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* [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64)
@ 2024-07-02 13:51 Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 01/23] powerpc/64e: Remove unused IBM HTW code Christophe Leroy
                   ` (22 more replies)
  0 siblings, 23 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

This series should have reached maturity for linux-next.

Version v7 is rebased on top of mm-unstable (9bb8753acdd8)

Also see https://github.com/linuxppc/issues/issues/483

Unlike most architectures, powerpc 8xx HW requires a two-level
pagetable topology for all page sizes. So a leaf PMD-contig approach
is not feasible as such.

Possible sizes on 8xx are 4k, 16k, 512k and 8M.

First level (PGD/PMD) covers 4M per entry. For 8M pages, two PMD entries
must point to a single entry level-2 page table. Until now that was
done using hugepd. This series changes it to use standard page tables
where the entry is replicated 1024 times on each of the two pagetables
refered by the two associated PMD entries for that 8M page.

For e500 and book3s/64 there are less constraints because it is not
tied to the HW assisted tablewalk like on 8xx, so it is easier to use
leaf PMDs (and PUDs).

On e500 the supported page sizes are 4M, 16M, 64M, 256M and 1G. All at
PMD level on e500/32 (mpc85xx) and mix of PMD and PUD for e500/64. We
encode page size with 4 available bits in PTE entries. On e300/32 PGD
entries size is increases to 64 bits in order to allow leaf-PMD entries
because PTE are 64 bits on e500.

On book3s/64 only the hash-4k mode is concerned. It supports 16M pages
as cont-PMD and 16G pages as cont-PUD. In other modes (radix-4k, radix-6k
and hash-64k) the sizes match with PMD and PUD sizes so that's just leaf
entries. The hash processing make things a bit more complex. To ease
things, __hash_page_huge() is modified to bail out when DIRTY or ACCESSED
bits are missing, leaving it to mm core to fix it.

Global changes in v7:
- Rebased on top of mm-unstable (9bb8753acdd8)
- Added Ack from Michael on patch 21

Global changes in v6:
- Unsquashed preliminary series from Michael so that everything gets merged together through mm
- In patch 3, removed the modification of pte-40x.h, because 40x is going away completely in another series. This has no impact.
- Added a WARN_ON_ONCE() in patch 21 as commented by Oscar.

Global changes in v5:
- Now use PAGE SIZE field in e500's PTE to store TSIZE instead of using U0-U3
- On e500/64, use highest bit to discriminate leaf entries because PUD entries are not garantied to be 4k aligned so PAGE SIZE field is not garantied to be 0 on a non-leaf entry.

Global changes in v4:
- Fixed a few issues reported privately by robots
- Rebased on top of v6.10-rc1

Global changes in v3:
- Removed patches 1 and 2
- Squashed patch 11 into patch 5
- Replaced patches 12 and 13 with a series from Michael
- Reordered patches a bit to have more general patches up front

For more details on changes, see in each patch.

Christophe Leroy (17):
  mm: Define __pte_leaf_size() to also take a PMD entry
  mm: Provide mm_struct and address to huge_ptep_get()
  powerpc/mm: Remove _PAGE_PSIZE
  powerpc/mm: Fix __find_linux_pte() on 32 bits with PMD leaf entries
  powerpc/mm: Allow hugepages without hugepd
  powerpc/8xx: Fix size given to set_huge_pte_at()
  powerpc/8xx: Rework support for 8M pages using contiguous PTE entries
  powerpc/8xx: Simplify struct mmu_psize_def
  powerpc/e500: Remove enc and ind fields from struct mmu_psize_def
  powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits)
  powerpc/e500: Encode hugepage size in PTE bits
  powerpc/e500: Don't pre-check write access on data TLB error
  powerpc/e500: Free r10 for FIND_PTE
  powerpc/e500: Use contiguous PMD instead of hugepd
  powerpc/64s: Use contiguous PMD/PUD instead of HUGEPD
  powerpc/mm: Remove hugepd leftovers
  mm: Remove CONFIG_ARCH_HAS_HUGEPD

Michael Ellerman (6):
  powerpc/64e: Remove unused IBM HTW code
  powerpc/64e: Split out nohash Book3E 64-bit code
  powerpc/64e: Drop E500 ifdefs in 64-bit code
  powerpc/64e: Drop MMU_FTR_TYPE_FSL_E checks in 64-bit code
  powerpc/64e: Consolidate TLB miss handler patching
  powerpc/64e: Drop unused TLB miss handlers

 arch/arm/include/asm/hugetlb-3level.h         |   4 +-
 arch/arm64/include/asm/hugetlb.h              |   2 +-
 arch/arm64/mm/hugetlbpage.c                   |   2 +-
 arch/powerpc/Kconfig                          |   1 -
 arch/powerpc/include/asm/book3s/32/pgalloc.h  |   2 -
 arch/powerpc/include/asm/book3s/64/hash-4k.h  |  15 -
 arch/powerpc/include/asm/book3s/64/hash.h     |  40 +-
 arch/powerpc/include/asm/book3s/64/hugetlb.h  |  38 --
 .../include/asm/book3s/64/pgtable-4k.h        |  47 --
 .../include/asm/book3s/64/pgtable-64k.h       |  20 -
 arch/powerpc/include/asm/book3s/64/pgtable.h  |  22 +-
 arch/powerpc/include/asm/hugetlb.h            |  15 +-
 .../include/asm/nohash/32/hugetlb-8xx.h       |  38 +-
 arch/powerpc/include/asm/nohash/32/mmu-8xx.h  |   9 +-
 arch/powerpc/include/asm/nohash/32/pte-44x.h  |   3 -
 arch/powerpc/include/asm/nohash/32/pte-85xx.h |   3 -
 arch/powerpc/include/asm/nohash/32/pte-8xx.h  |  58 ++-
 .../powerpc/include/asm/nohash/hugetlb-e500.h |  39 +-
 arch/powerpc/include/asm/nohash/mmu-e500.h    |   6 +-
 arch/powerpc/include/asm/nohash/pgalloc.h     |   2 -
 arch/powerpc/include/asm/nohash/pgtable.h     |  46 +-
 arch/powerpc/include/asm/nohash/pte-e500.h    |  63 ++-
 arch/powerpc/include/asm/page.h               |  32 --
 arch/powerpc/include/asm/pgtable-be-types.h   |  10 -
 arch/powerpc/include/asm/pgtable-types.h      |  13 +-
 arch/powerpc/include/asm/pgtable.h            |   3 +
 arch/powerpc/kernel/exceptions-64e.S          |   4 +-
 arch/powerpc/kernel/head_85xx.S               |  70 +--
 arch/powerpc/kernel/head_8xx.S                |  10 +-
 arch/powerpc/kernel/setup_64.c                |   6 +-
 arch/powerpc/mm/book3s64/hash_utils.c         |  11 +-
 arch/powerpc/mm/book3s64/hugetlbpage.c        |  10 +
 arch/powerpc/mm/book3s64/pgtable.c            |  12 -
 arch/powerpc/mm/hugetlbpage.c                 | 455 +-----------------
 arch/powerpc/mm/init-common.c                 |   8 +-
 arch/powerpc/mm/kasan/8xx.c                   |  21 +-
 arch/powerpc/mm/nohash/8xx.c                  |  43 +-
 arch/powerpc/mm/nohash/Makefile               |   2 +-
 arch/powerpc/mm/nohash/book3e_pgtable.c       |   4 +-
 arch/powerpc/mm/nohash/tlb.c                  | 407 +---------------
 arch/powerpc/mm/nohash/tlb_64e.c              | 314 ++++++++++++
 arch/powerpc/mm/nohash/tlb_low_64e.S          | 428 +---------------
 arch/powerpc/mm/pgtable.c                     |  94 ++--
 arch/powerpc/mm/pgtable_32.c                  |   2 +-
 arch/riscv/include/asm/hugetlb.h              |   2 +-
 arch/riscv/mm/hugetlbpage.c                   |   2 +-
 arch/s390/include/asm/hugetlb.h               |   4 +-
 arch/s390/mm/hugetlbpage.c                    |   4 +-
 fs/hugetlbfs/inode.c                          |   2 +-
 fs/proc/task_mmu.c                            |  10 +-
 fs/userfaultfd.c                              |   2 +-
 include/asm-generic/hugetlb.h                 |   2 +-
 include/linux/hugetlb.h                       |   6 -
 include/linux/pgtable.h                       |   3 +
 include/linux/swapops.h                       |   4 +-
 kernel/events/core.c                          |   2 +-
 mm/Kconfig                                    |  10 -
 mm/damon/vaddr.c                              |   6 +-
 mm/gup.c                                      | 194 +-------
 mm/hmm.c                                      |   2 +-
 mm/hugetlb.c                                  |  44 +-
 mm/memory-failure.c                           |   2 +-
 mm/mempolicy.c                                |   2 +-
 mm/migrate.c                                  |   4 +-
 mm/mincore.c                                  |   2 +-
 mm/pagewalk.c                                 |  57 +--
 mm/userfaultfd.c                              |   2 +-
 67 files changed, 751 insertions(+), 2051 deletions(-)
 delete mode 100644 arch/powerpc/include/asm/book3s/64/pgtable-4k.h
 create mode 100644 arch/powerpc/mm/nohash/tlb_64e.c

-- 
2.44.0



^ permalink raw reply	[flat|nested] 28+ messages in thread

* [PATCH v7 01/23] powerpc/64e: Remove unused IBM HTW code
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 02/23] powerpc/64e: Split out nohash Book3E 64-bit code Christophe Leroy
                   ` (21 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

From: Michael Ellerman <mpe@ellerman.id.au>

The nohash HTW_IBM (Hardware Table Walk) code is unused since support
for A2 was removed in commit fb5a515704d7 ("powerpc: Remove platforms/
wsp and associated pieces") (2014).

The remaining supported CPUs use either no HTW (data_tlb_miss_bolted),
or the e6500 HTW (data_tlb_miss_e6500).

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/nohash/mmu-e500.h |   3 +-
 arch/powerpc/mm/nohash/tlb.c               |  57 +-----
 arch/powerpc/mm/nohash/tlb_low_64e.S       | 195 ---------------------
 3 files changed, 2 insertions(+), 253 deletions(-)

diff --git a/arch/powerpc/include/asm/nohash/mmu-e500.h b/arch/powerpc/include/asm/nohash/mmu-e500.h
index 6ddced0415cb..7dc24b8632d7 100644
--- a/arch/powerpc/include/asm/nohash/mmu-e500.h
+++ b/arch/powerpc/include/asm/nohash/mmu-e500.h
@@ -303,8 +303,7 @@ extern unsigned long linear_map_top;
 extern int book3e_htw_mode;
 
 #define PPC_HTW_NONE	0
-#define PPC_HTW_IBM	1
-#define PPC_HTW_E6500	2
+#define PPC_HTW_E6500	1
 
 /*
  * 64-bit booke platforms don't load the tlb in the tlb miss handler code.
diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb.c
index 5ffa0af4328a..a5bb87ec8578 100644
--- a/arch/powerpc/mm/nohash/tlb.c
+++ b/arch/powerpc/mm/nohash/tlb.c
@@ -400,9 +400,8 @@ void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address)
 static void __init setup_page_sizes(void)
 {
 	unsigned int tlb0cfg;
-	unsigned int tlb0ps;
 	unsigned int eptcfg;
-	int i, psize;
+	int psize;
 
 #ifdef CONFIG_PPC_E500
 	unsigned int mmucfg = mfspr(SPRN_MMUCFG);
@@ -471,50 +470,6 @@ static void __init setup_page_sizes(void)
 		goto out;
 	}
 #endif
-
-	tlb0cfg = mfspr(SPRN_TLB0CFG);
-	tlb0ps = mfspr(SPRN_TLB0PS);
-	eptcfg = mfspr(SPRN_EPTCFG);
-
-	/* Look for supported direct sizes */
-	for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
-		struct mmu_psize_def *def = &mmu_psize_defs[psize];
-
-		if (tlb0ps & (1U << (def->shift - 10)))
-			def->flags |= MMU_PAGE_SIZE_DIRECT;
-	}
-
-	/* Indirect page sizes supported ? */
-	if ((tlb0cfg & TLBnCFG_IND) == 0 ||
-	    (tlb0cfg & TLBnCFG_PT) == 0)
-		goto out;
-
-	book3e_htw_mode = PPC_HTW_IBM;
-
-	/* Now, we only deal with one IND page size for each
-	 * direct size. Hopefully all implementations today are
-	 * unambiguous, but we might want to be careful in the
-	 * future.
-	 */
-	for (i = 0; i < 3; i++) {
-		unsigned int ps, sps;
-
-		sps = eptcfg & 0x1f;
-		eptcfg >>= 5;
-		ps = eptcfg & 0x1f;
-		eptcfg >>= 5;
-		if (!ps || !sps)
-			continue;
-		for (psize = 0; psize < MMU_PAGE_COUNT; psize++) {
-			struct mmu_psize_def *def = &mmu_psize_defs[psize];
-
-			if (ps == (def->shift - 10))
-				def->flags |= MMU_PAGE_SIZE_INDIRECT;
-			if (sps == (def->shift - 10))
-				def->ind = ps + 10;
-		}
-	}
-
 out:
 	/* Cleanup array and print summary */
 	pr_info("MMU: Supported page sizes\n");
@@ -543,10 +498,6 @@ static void __init setup_mmu_htw(void)
 	 */
 
 	switch (book3e_htw_mode) {
-	case PPC_HTW_IBM:
-		patch_exception(0x1c0, exc_data_tlb_miss_htw_book3e);
-		patch_exception(0x1e0, exc_instruction_tlb_miss_htw_book3e);
-		break;
 #ifdef CONFIG_PPC_E500
 	case PPC_HTW_E6500:
 		extlb_level_exc = EX_TLB_SIZE;
@@ -577,12 +528,6 @@ static void early_init_this_mmu(void)
 		mmu_pte_psize = MMU_PAGE_2M;
 		break;
 
-	case PPC_HTW_IBM:
-		mas4 |= MAS4_INDD;
-		mas4 |=	BOOK3E_PAGESZ_1M << MAS4_TSIZED_SHIFT;
-		mmu_pte_psize = MMU_PAGE_1M;
-		break;
-
 	case PPC_HTW_NONE:
 		mas4 |=	BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT;
 		mmu_pte_psize = mmu_virtual_psize;
diff --git a/arch/powerpc/mm/nohash/tlb_low_64e.S b/arch/powerpc/mm/nohash/tlb_low_64e.S
index 7e0b8fe1c279..b0eb3f7eaed1 100644
--- a/arch/powerpc/mm/nohash/tlb_low_64e.S
+++ b/arch/powerpc/mm/nohash/tlb_low_64e.S
@@ -893,201 +893,6 @@ virt_page_table_tlb_miss_whacko_fault:
 	TLB_MISS_EPILOG_ERROR
 	b	exc_data_storage_book3e
 
-
-/**************************************************************
- *                                                            *
- * TLB miss handling for Book3E with hw page table support    *
- *                                                            *
- **************************************************************/
-
-
-/* Data TLB miss */
-	START_EXCEPTION(data_tlb_miss_htw)
-	TLB_MISS_PROLOG
-
-	/* Now we handle the fault proper. We only save DEAR in normal
-	 * fault case since that's the only interesting values here.
-	 * We could probably also optimize by not saving SRR0/1 in the
-	 * linear mapping case but I'll leave that for later
-	 */
-	mfspr	r14,SPRN_ESR
-	mfspr	r16,SPRN_DEAR		/* get faulting address */
-	srdi	r11,r16,44		/* get region */
-	xoris	r11,r11,0xc
-	cmpldi	cr0,r11,0		/* linear mapping ? */
-	beq	tlb_load_linear		/* yes -> go to linear map load */
-	cmpldi	cr1,r11,1		/* vmalloc mapping ? */
-
-	/* We do the user/kernel test for the PID here along with the RW test
-	 */
-	srdi.	r11,r16,60		/* Check for user region */
-	ld	r15,PACAPGD(r13)	/* Load user pgdir */
-	beq	htw_tlb_miss
-
-	/* XXX replace the RMW cycles with immediate loads + writes */
-1:	mfspr	r10,SPRN_MAS1
-	rlwinm	r10,r10,0,16,1		/* Clear TID */
-	mtspr	SPRN_MAS1,r10
-	ld	r15,PACA_KERNELPGD(r13)	/* Load kernel pgdir */
-	beq+	cr1,htw_tlb_miss
-
-	/* We got a crappy address, just fault with whatever DEAR and ESR
-	 * are here
-	 */
-	TLB_MISS_EPILOG_ERROR
-	b	exc_data_storage_book3e
-
-/* Instruction TLB miss */
-	START_EXCEPTION(instruction_tlb_miss_htw)
-	TLB_MISS_PROLOG
-
-	/* If we take a recursive fault, the second level handler may need
-	 * to know whether we are handling a data or instruction fault in
-	 * order to get to the right store fault handler. We provide that
-	 * info by keeping a crazy value for ESR in r14
-	 */
-	li	r14,-1	/* store to exception frame is done later */
-
-	/* Now we handle the fault proper. We only save DEAR in the non
-	 * linear mapping case since we know the linear mapping case will
-	 * not re-enter. We could indeed optimize and also not save SRR0/1
-	 * in the linear mapping case but I'll leave that for later
-	 *
-	 * Faulting address is SRR0 which is already in r16
-	 */
-	srdi	r11,r16,44		/* get region */
-	xoris	r11,r11,0xc
-	cmpldi	cr0,r11,0		/* linear mapping ? */
-	beq	tlb_load_linear		/* yes -> go to linear map load */
-	cmpldi	cr1,r11,1		/* vmalloc mapping ? */
-
-	/* We do the user/kernel test for the PID here along with the RW test
-	 */
-	srdi.	r11,r16,60		/* Check for user region */
-	ld	r15,PACAPGD(r13)		/* Load user pgdir */
-	beq	htw_tlb_miss
-
-	/* XXX replace the RMW cycles with immediate loads + writes */
-1:	mfspr	r10,SPRN_MAS1
-	rlwinm	r10,r10,0,16,1			/* Clear TID */
-	mtspr	SPRN_MAS1,r10
-	ld	r15,PACA_KERNELPGD(r13)		/* Load kernel pgdir */
-	beq+	htw_tlb_miss
-
-	/* We got a crappy address, just fault */
-	TLB_MISS_EPILOG_ERROR
-	b	exc_instruction_storage_book3e
-
-
-/*
- * This is the guts of the second-level TLB miss handler for direct
- * misses. We are entered with:
- *
- * r16 = virtual page table faulting address
- * r15 = PGD pointer
- * r14 = ESR
- * r13 = PACA
- * r12 = TLB exception frame in PACA
- * r11 = crap (free to use)
- * r10 = crap (free to use)
- *
- * It can be re-entered by the linear mapping miss handler. However, to
- * avoid too much complication, it will save/restore things for us
- */
-htw_tlb_miss:
-#ifdef CONFIG_PPC_KUAP
-	mfspr	r10,SPRN_MAS1
-	rlwinm.	r10,r10,0,0x3fff0000
-	beq-	htw_tlb_miss_fault /* KUAP fault */
-#endif
-	/* Search if we already have a TLB entry for that virtual address, and
-	 * if we do, bail out.
-	 *
-	 * MAS1:IND should be already set based on MAS4
-	 */
-	PPC_TLBSRX_DOT(0,R16)
-	beq	htw_tlb_miss_done
-
-	/* Now, we need to walk the page tables. First check if we are in
-	 * range.
-	 */
-	rldicl.	r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
-	bne-	htw_tlb_miss_fault
-
-	/* Get the PGD pointer */
-	cmpldi	cr0,r15,0
-	beq-	htw_tlb_miss_fault
-
-	/* Get to PGD entry */
-	rldicl	r11,r16,64-(PGDIR_SHIFT-3),64-PGD_INDEX_SIZE-3
-	clrrdi	r10,r11,3
-	ldx	r15,r10,r15
-	cmpdi	cr0,r15,0
-	bge	htw_tlb_miss_fault
-
-	/* Get to PUD entry */
-	rldicl	r11,r16,64-(PUD_SHIFT-3),64-PUD_INDEX_SIZE-3
-	clrrdi	r10,r11,3
-	ldx	r15,r10,r15
-	cmpdi	cr0,r15,0
-	bge	htw_tlb_miss_fault
-
-	/* Get to PMD entry */
-	rldicl	r11,r16,64-(PMD_SHIFT-3),64-PMD_INDEX_SIZE-3
-	clrrdi	r10,r11,3
-	ldx	r15,r10,r15
-	cmpdi	cr0,r15,0
-	bge	htw_tlb_miss_fault
-
-	/* Ok, we're all right, we can now create an indirect entry for
-	 * a 1M or 256M page.
-	 *
-	 * The last trick is now that because we use "half" pages for
-	 * the HTW (1M IND is 2K and 256M IND is 32K) we need to account
-	 * for an added LSB bit to the RPN. For 64K pages, there is no
-	 * problem as we already use 32K arrays (half PTE pages), but for
-	 * 4K page we need to extract a bit from the virtual address and
-	 * insert it into the "PA52" bit of the RPN.
-	 */
-	rlwimi	r15,r16,32-9,20,20
-	/* Now we build the MAS:
-	 *
-	 * MAS 0   :	Fully setup with defaults in MAS4 and TLBnCFG
-	 * MAS 1   :	Almost fully setup
-	 *               - PID already updated by caller if necessary
-	 *               - TSIZE for now is base ind page size always
-	 * MAS 2   :	Use defaults
-	 * MAS 3+7 :	Needs to be done
-	 */
-	ori	r10,r15,(BOOK3E_PAGESZ_4K << MAS3_SPSIZE_SHIFT)
-
-	srdi	r16,r10,32
-	mtspr	SPRN_MAS3,r10
-	mtspr	SPRN_MAS7,r16
-
-	tlbwe
-
-htw_tlb_miss_done:
-	/* We don't bother with restoring DEAR or ESR since we know we are
-	 * level 0 and just going back to userland. They are only needed
-	 * if you are going to take an access fault
-	 */
-	TLB_MISS_EPILOG_SUCCESS
-	rfi
-
-htw_tlb_miss_fault:
-	/* We need to check if it was an instruction miss. We know this
-	 * though because r14 would contain -1
-	 */
-	cmpdi	cr0,r14,-1
-	beq	1f
-	mtspr	SPRN_DEAR,r16
-	mtspr	SPRN_ESR,r14
-	TLB_MISS_EPILOG_ERROR
-	b	exc_data_storage_book3e
-1:	TLB_MISS_EPILOG_ERROR
-	b	exc_instruction_storage_book3e
-
 /*
  * This is the guts of "any" level TLB miss handler for kernel linear
  * mapping misses. We are entered with:
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 02/23] powerpc/64e: Split out nohash Book3E 64-bit code
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 01/23] powerpc/64e: Remove unused IBM HTW code Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 03/23] powerpc/64e: Drop E500 ifdefs in " Christophe Leroy
                   ` (20 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

From: Michael Ellerman <mpe@ellerman.id.au>

A reasonable chunk of nohash/tlb.c is 64-bit only code, split it out
into a separate file.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/Makefile             |   2 +-
 arch/powerpc/mm/nohash/tlb.c                | 343 +-------------------
 arch/powerpc/mm/nohash/{tlb.c => tlb_64e.c} | 328 -------------------
 3 files changed, 2 insertions(+), 671 deletions(-)
 copy arch/powerpc/mm/nohash/{tlb.c => tlb_64e.c} (56%)

diff --git a/arch/powerpc/mm/nohash/Makefile b/arch/powerpc/mm/nohash/Makefile
index b3f0498dd42f..90e846f0c46c 100644
--- a/arch/powerpc/mm/nohash/Makefile
+++ b/arch/powerpc/mm/nohash/Makefile
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-y				+= mmu_context.o tlb.o tlb_low.o kup.o
-obj-$(CONFIG_PPC_BOOK3E_64)  	+= tlb_low_64e.o book3e_pgtable.o
+obj-$(CONFIG_PPC_BOOK3E_64)  	+= tlb_64e.o tlb_low_64e.o book3e_pgtable.o
 obj-$(CONFIG_40x)		+= 40x.o
 obj-$(CONFIG_44x)		+= 44x.o
 obj-$(CONFIG_PPC_8xx)		+= 8xx.o
diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb.c
index a5bb87ec8578..f57dc721d063 100644
--- a/arch/powerpc/mm/nohash/tlb.c
+++ b/arch/powerpc/mm/nohash/tlb.c
@@ -110,28 +110,6 @@ struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
 };
 #endif
 
-/* The variables below are currently only used on 64-bit Book3E
- * though this will probably be made common with other nohash
- * implementations at some point
- */
-#ifdef CONFIG_PPC64
-
-int mmu_pte_psize;		/* Page size used for PTE pages */
-int mmu_vmemmap_psize;		/* Page size used for the virtual mem map */
-int book3e_htw_mode;		/* HW tablewalk?  Value is PPC_HTW_* */
-unsigned long linear_map_top;	/* Top of linear mapping */
-
-
-/*
- * Number of bytes to add to SPRN_SPRG_TLB_EXFRAME on crit/mcheck/debug
- * exceptions.  This is used for bolted and e6500 TLB miss handlers which
- * do not modify this SPRG in the TLB miss code; for other TLB miss handlers,
- * this is set to zero.
- */
-int extlb_level_exc;
-
-#endif /* CONFIG_PPC64 */
-
 #ifdef CONFIG_PPC_E500
 /* next_tlbcam_idx is used to round-robin tlbcam entry assignment */
 DEFINE_PER_CPU(int, next_tlbcam_idx);
@@ -358,326 +336,7 @@ void tlb_flush(struct mmu_gather *tlb)
 	flush_tlb_mm(tlb->mm);
 }
 
-/*
- * Below are functions specific to the 64-bit variant of Book3E though that
- * may change in the future
- */
-
-#ifdef CONFIG_PPC64
-
-/*
- * Handling of virtual linear page tables or indirect TLB entries
- * flushing when PTE pages are freed
- */
-void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address)
-{
-	int tsize = mmu_psize_defs[mmu_pte_psize].enc;
-
-	if (book3e_htw_mode != PPC_HTW_NONE) {
-		unsigned long start = address & PMD_MASK;
-		unsigned long end = address + PMD_SIZE;
-		unsigned long size = 1UL << mmu_psize_defs[mmu_pte_psize].shift;
-
-		/* This isn't the most optimal, ideally we would factor out the
-		 * while preempt & CPU mask mucking around, or even the IPI but
-		 * it will do for now
-		 */
-		while (start < end) {
-			__flush_tlb_page(tlb->mm, start, tsize, 1);
-			start += size;
-		}
-	} else {
-		unsigned long rmask = 0xf000000000000000ul;
-		unsigned long rid = (address & rmask) | 0x1000000000000000ul;
-		unsigned long vpte = address & ~rmask;
-
-		vpte = (vpte >> (PAGE_SHIFT - 3)) & ~0xffful;
-		vpte |= rid;
-		__flush_tlb_page(tlb->mm, vpte, tsize, 0);
-	}
-}
-
-static void __init setup_page_sizes(void)
-{
-	unsigned int tlb0cfg;
-	unsigned int eptcfg;
-	int psize;
-
-#ifdef CONFIG_PPC_E500
-	unsigned int mmucfg = mfspr(SPRN_MMUCFG);
-	int fsl_mmu = mmu_has_feature(MMU_FTR_TYPE_FSL_E);
-
-	if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
-		unsigned int tlb1cfg = mfspr(SPRN_TLB1CFG);
-		unsigned int min_pg, max_pg;
-
-		min_pg = (tlb1cfg & TLBnCFG_MINSIZE) >> TLBnCFG_MINSIZE_SHIFT;
-		max_pg = (tlb1cfg & TLBnCFG_MAXSIZE) >> TLBnCFG_MAXSIZE_SHIFT;
-
-		for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
-			struct mmu_psize_def *def;
-			unsigned int shift;
-
-			def = &mmu_psize_defs[psize];
-			shift = def->shift;
-
-			if (shift == 0 || shift & 1)
-				continue;
-
-			/* adjust to be in terms of 4^shift Kb */
-			shift = (shift - 10) >> 1;
-
-			if ((shift >= min_pg) && (shift <= max_pg))
-				def->flags |= MMU_PAGE_SIZE_DIRECT;
-		}
-
-		goto out;
-	}
-
-	if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V2) {
-		u32 tlb1cfg, tlb1ps;
-
-		tlb0cfg = mfspr(SPRN_TLB0CFG);
-		tlb1cfg = mfspr(SPRN_TLB1CFG);
-		tlb1ps = mfspr(SPRN_TLB1PS);
-		eptcfg = mfspr(SPRN_EPTCFG);
-
-		if ((tlb1cfg & TLBnCFG_IND) && (tlb0cfg & TLBnCFG_PT))
-			book3e_htw_mode = PPC_HTW_E6500;
-
-		/*
-		 * We expect 4K subpage size and unrestricted indirect size.
-		 * The lack of a restriction on indirect size is a Freescale
-		 * extension, indicated by PSn = 0 but SPSn != 0.
-		 */
-		if (eptcfg != 2)
-			book3e_htw_mode = PPC_HTW_NONE;
-
-		for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
-			struct mmu_psize_def *def = &mmu_psize_defs[psize];
-
-			if (!def->shift)
-				continue;
-
-			if (tlb1ps & (1U << (def->shift - 10))) {
-				def->flags |= MMU_PAGE_SIZE_DIRECT;
-
-				if (book3e_htw_mode && psize == MMU_PAGE_2M)
-					def->flags |= MMU_PAGE_SIZE_INDIRECT;
-			}
-		}
-
-		goto out;
-	}
-#endif
-out:
-	/* Cleanup array and print summary */
-	pr_info("MMU: Supported page sizes\n");
-	for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
-		struct mmu_psize_def *def = &mmu_psize_defs[psize];
-		const char *__page_type_names[] = {
-			"unsupported",
-			"direct",
-			"indirect",
-			"direct & indirect"
-		};
-		if (def->flags == 0) {
-			def->shift = 0;	
-			continue;
-		}
-		pr_info("  %8ld KB as %s\n", 1ul << (def->shift - 10),
-			__page_type_names[def->flags & 0x3]);
-	}
-}
-
-static void __init setup_mmu_htw(void)
-{
-	/*
-	 * If we want to use HW tablewalk, enable it by patching the TLB miss
-	 * handlers to branch to the one dedicated to it.
-	 */
-
-	switch (book3e_htw_mode) {
-#ifdef CONFIG_PPC_E500
-	case PPC_HTW_E6500:
-		extlb_level_exc = EX_TLB_SIZE;
-		patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e);
-		patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e);
-		break;
-#endif
-	}
-	pr_info("MMU: Book3E HW tablewalk %s\n",
-		book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported");
-}
-
-/*
- * Early initialization of the MMU TLB code
- */
-static void early_init_this_mmu(void)
-{
-	unsigned int mas4;
-
-	/* Set MAS4 based on page table setting */
-
-	mas4 = 0x4 << MAS4_WIMGED_SHIFT;
-	switch (book3e_htw_mode) {
-	case PPC_HTW_E6500:
-		mas4 |= MAS4_INDD;
-		mas4 |= BOOK3E_PAGESZ_2M << MAS4_TSIZED_SHIFT;
-		mas4 |= MAS4_TLBSELD(1);
-		mmu_pte_psize = MMU_PAGE_2M;
-		break;
-
-	case PPC_HTW_NONE:
-		mas4 |=	BOOK3E_PAGESZ_4K << MAS4_TSIZED_SHIFT;
-		mmu_pte_psize = mmu_virtual_psize;
-		break;
-	}
-	mtspr(SPRN_MAS4, mas4);
-
-#ifdef CONFIG_PPC_E500
-	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
-		unsigned int num_cams;
-		bool map = true;
-
-		/* use a quarter of the TLBCAM for bolted linear map */
-		num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
-
-		/*
-		 * Only do the mapping once per core, or else the
-		 * transient mapping would cause problems.
-		 */
-#ifdef CONFIG_SMP
-		if (hweight32(get_tensr()) > 1)
-			map = false;
-#endif
-
-		if (map)
-			linear_map_top = map_mem_in_cams(linear_map_top,
-							 num_cams, false, true);
-	}
-#endif
-
-	/* A sync won't hurt us after mucking around with
-	 * the MMU configuration
-	 */
-	mb();
-}
-
-static void __init early_init_mmu_global(void)
-{
-	/* XXX This should be decided at runtime based on supported
-	 * page sizes in the TLB, but for now let's assume 16M is
-	 * always there and a good fit (which it probably is)
-	 *
-	 * Freescale booke only supports 4K pages in TLB0, so use that.
-	 */
-	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
-		mmu_vmemmap_psize = MMU_PAGE_4K;
-	else
-		mmu_vmemmap_psize = MMU_PAGE_16M;
-
-	/* XXX This code only checks for TLB 0 capabilities and doesn't
-	 *     check what page size combos are supported by the HW. It
-	 *     also doesn't handle the case where a separate array holds
-	 *     the IND entries from the array loaded by the PT.
-	 */
-	/* Look for supported page sizes */
-	setup_page_sizes();
-
-	/* Look for HW tablewalk support */
-	setup_mmu_htw();
-
-#ifdef CONFIG_PPC_E500
-	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
-		if (book3e_htw_mode == PPC_HTW_NONE) {
-			extlb_level_exc = EX_TLB_SIZE;
-			patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e);
-			patch_exception(0x1e0,
-				exc_instruction_tlb_miss_bolted_book3e);
-		}
-	}
-#endif
-
-	/* Set the global containing the top of the linear mapping
-	 * for use by the TLB miss code
-	 */
-	linear_map_top = memblock_end_of_DRAM();
-
-	ioremap_bot = IOREMAP_BASE;
-}
-
-static void __init early_mmu_set_memory_limit(void)
-{
-#ifdef CONFIG_PPC_E500
-	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
-		/*
-		 * Limit memory so we dont have linear faults.
-		 * Unlike memblock_set_current_limit, which limits
-		 * memory available during early boot, this permanently
-		 * reduces the memory available to Linux.  We need to
-		 * do this because highmem is not supported on 64-bit.
-		 */
-		memblock_enforce_memory_limit(linear_map_top);
-	}
-#endif
-
-	memblock_set_current_limit(linear_map_top);
-}
-
-/* boot cpu only */
-void __init early_init_mmu(void)
-{
-	early_init_mmu_global();
-	early_init_this_mmu();
-	early_mmu_set_memory_limit();
-}
-
-void early_init_mmu_secondary(void)
-{
-	early_init_this_mmu();
-}
-
-void setup_initial_memory_limit(phys_addr_t first_memblock_base,
-				phys_addr_t first_memblock_size)
-{
-	/* On non-FSL Embedded 64-bit, we adjust the RMA size to match
-	 * the bolted TLB entry. We know for now that only 1G
-	 * entries are supported though that may eventually
-	 * change.
-	 *
-	 * on FSL Embedded 64-bit, usually all RAM is bolted, but with
-	 * unusual memory sizes it's possible for some RAM to not be mapped
-	 * (such RAM is not used at all by Linux, since we don't support
-	 * highmem on 64-bit).  We limit ppc64_rma_size to what would be
-	 * mappable if this memblock is the only one.  Additional memblocks
-	 * can only increase, not decrease, the amount that ends up getting
-	 * mapped.  We still limit max to 1G even if we'll eventually map
-	 * more.  This is due to what the early init code is set up to do.
-	 *
-	 * We crop it to the size of the first MEMBLOCK to
-	 * avoid going over total available memory just in case...
-	 */
-#ifdef CONFIG_PPC_E500
-	if (early_mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
-		unsigned long linear_sz;
-		unsigned int num_cams;
-
-		/* use a quarter of the TLBCAM for bolted linear map */
-		num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
-
-		linear_sz = map_mem_in_cams(first_memblock_size, num_cams,
-					    true, true);
-
-		ppc64_rma_size = min_t(u64, linear_sz, 0x40000000);
-	} else
-#endif
-		ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
-
-	/* Finally limit subsequent allocations */
-	memblock_set_current_limit(first_memblock_base + ppc64_rma_size);
-}
-#else /* ! CONFIG_PPC64 */
+#ifndef CONFIG_PPC64
 void __init early_init_mmu(void)
 {
 	unsigned long root = of_get_flat_dt_root();
diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb_64e.c
similarity index 56%
copy from arch/powerpc/mm/nohash/tlb.c
copy to arch/powerpc/mm/nohash/tlb_64e.c
index a5bb87ec8578..7d5506d23eab 100644
--- a/arch/powerpc/mm/nohash/tlb.c
+++ b/arch/powerpc/mm/nohash/tlb_64e.c
@@ -1,13 +1,5 @@
 // SPDX-License-Identifier: GPL-2.0-or-later
 /*
- * This file contains the routines for TLB flushing.
- * On machines where the MMU does not use a hash table to store virtual to
- * physical translations (ie, SW loaded TLBs or Book3E compilant processors,
- * this does -not- include 603 however which shares the implementation with
- * hash based processors)
- *
- *  -- BenH
- *
  * Copyright 2008,2009 Ben Herrenschmidt <benh@kernel.crashing.org>
  *                     IBM Corp.
  *
@@ -26,96 +18,21 @@
 #include <linux/export.h>
 #include <linux/mm.h>
 #include <linux/init.h>
-#include <linux/highmem.h>
 #include <linux/pagemap.h>
-#include <linux/preempt.h>
-#include <linux/spinlock.h>
 #include <linux/memblock.h>
-#include <linux/of_fdt.h>
-#include <linux/hugetlb.h>
 
 #include <asm/pgalloc.h>
 #include <asm/tlbflush.h>
 #include <asm/tlb.h>
 #include <asm/code-patching.h>
 #include <asm/cputhreads.h>
-#include <asm/hugetlb.h>
-#include <asm/paca.h>
 
 #include <mm/mmu_decl.h>
 
-/*
- * This struct lists the sw-supported page sizes.  The hardawre MMU may support
- * other sizes not listed here.   The .ind field is only used on MMUs that have
- * indirect page table entries.
- */
-#ifdef CONFIG_PPC_E500
-struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
-	[MMU_PAGE_4K] = {
-		.shift	= 12,
-		.enc	= BOOK3E_PAGESZ_4K,
-	},
-	[MMU_PAGE_2M] = {
-		.shift	= 21,
-		.enc	= BOOK3E_PAGESZ_2M,
-	},
-	[MMU_PAGE_4M] = {
-		.shift	= 22,
-		.enc	= BOOK3E_PAGESZ_4M,
-	},
-	[MMU_PAGE_16M] = {
-		.shift	= 24,
-		.enc	= BOOK3E_PAGESZ_16M,
-	},
-	[MMU_PAGE_64M] = {
-		.shift	= 26,
-		.enc	= BOOK3E_PAGESZ_64M,
-	},
-	[MMU_PAGE_256M] = {
-		.shift	= 28,
-		.enc	= BOOK3E_PAGESZ_256M,
-	},
-	[MMU_PAGE_1G] = {
-		.shift	= 30,
-		.enc	= BOOK3E_PAGESZ_1GB,
-	},
-};
-
-static inline int mmu_get_tsize(int psize)
-{
-	return mmu_psize_defs[psize].enc;
-}
-#else
-static inline int mmu_get_tsize(int psize)
-{
-	/* This isn't used on !Book3E for now */
-	return 0;
-}
-#endif
-
-#ifdef CONFIG_PPC_8xx
-struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
-	[MMU_PAGE_4K] = {
-		.shift	= 12,
-	},
-	[MMU_PAGE_16K] = {
-		.shift	= 14,
-	},
-	[MMU_PAGE_512K] = {
-		.shift	= 19,
-	},
-	[MMU_PAGE_8M] = {
-		.shift	= 23,
-	},
-};
-#endif
-
 /* The variables below are currently only used on 64-bit Book3E
  * though this will probably be made common with other nohash
  * implementations at some point
  */
-#ifdef CONFIG_PPC64
-
 int mmu_pte_psize;		/* Page size used for PTE pages */
 int mmu_vmemmap_psize;		/* Page size used for the virtual mem map */
 int book3e_htw_mode;		/* HW tablewalk?  Value is PPC_HTW_* */
@@ -130,241 +47,6 @@ unsigned long linear_map_top;	/* Top of linear mapping */
  */
 int extlb_level_exc;
 
-#endif /* CONFIG_PPC64 */
-
-#ifdef CONFIG_PPC_E500
-/* next_tlbcam_idx is used to round-robin tlbcam entry assignment */
-DEFINE_PER_CPU(int, next_tlbcam_idx);
-EXPORT_PER_CPU_SYMBOL(next_tlbcam_idx);
-#endif
-
-/*
- * Base TLB flushing operations:
- *
- *  - flush_tlb_mm(mm) flushes the specified mm context TLB's
- *  - flush_tlb_page(vma, vmaddr) flushes one page
- *  - flush_tlb_range(vma, start, end) flushes a range of pages
- *  - flush_tlb_kernel_range(start, end) flushes kernel pages
- *
- *  - local_* variants of page and mm only apply to the current
- *    processor
- */
-
-#ifndef CONFIG_PPC_8xx
-/*
- * These are the base non-SMP variants of page and mm flushing
- */
-void local_flush_tlb_mm(struct mm_struct *mm)
-{
-	unsigned int pid;
-
-	preempt_disable();
-	pid = mm->context.id;
-	if (pid != MMU_NO_CONTEXT)
-		_tlbil_pid(pid);
-	preempt_enable();
-}
-EXPORT_SYMBOL(local_flush_tlb_mm);
-
-void __local_flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
-			    int tsize, int ind)
-{
-	unsigned int pid;
-
-	preempt_disable();
-	pid = mm ? mm->context.id : 0;
-	if (pid != MMU_NO_CONTEXT)
-		_tlbil_va(vmaddr, pid, tsize, ind);
-	preempt_enable();
-}
-
-void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
-{
-	__local_flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
-			       mmu_get_tsize(mmu_virtual_psize), 0);
-}
-EXPORT_SYMBOL(local_flush_tlb_page);
-
-void local_flush_tlb_page_psize(struct mm_struct *mm,
-				unsigned long vmaddr, int psize)
-{
-	__local_flush_tlb_page(mm, vmaddr, mmu_get_tsize(psize), 0);
-}
-EXPORT_SYMBOL(local_flush_tlb_page_psize);
-
-#endif
-
-/*
- * And here are the SMP non-local implementations
- */
-#ifdef CONFIG_SMP
-
-static DEFINE_RAW_SPINLOCK(tlbivax_lock);
-
-struct tlb_flush_param {
-	unsigned long addr;
-	unsigned int pid;
-	unsigned int tsize;
-	unsigned int ind;
-};
-
-static void do_flush_tlb_mm_ipi(void *param)
-{
-	struct tlb_flush_param *p = param;
-
-	_tlbil_pid(p ? p->pid : 0);
-}
-
-static void do_flush_tlb_page_ipi(void *param)
-{
-	struct tlb_flush_param *p = param;
-
-	_tlbil_va(p->addr, p->pid, p->tsize, p->ind);
-}
-
-
-/* Note on invalidations and PID:
- *
- * We snapshot the PID with preempt disabled. At this point, it can still
- * change either because:
- * - our context is being stolen (PID -> NO_CONTEXT) on another CPU
- * - we are invaliating some target that isn't currently running here
- *   and is concurrently acquiring a new PID on another CPU
- * - some other CPU is re-acquiring a lost PID for this mm
- * etc...
- *
- * However, this shouldn't be a problem as we only guarantee
- * invalidation of TLB entries present prior to this call, so we
- * don't care about the PID changing, and invalidating a stale PID
- * is generally harmless.
- */
-
-void flush_tlb_mm(struct mm_struct *mm)
-{
-	unsigned int pid;
-
-	preempt_disable();
-	pid = mm->context.id;
-	if (unlikely(pid == MMU_NO_CONTEXT))
-		goto no_context;
-	if (!mm_is_core_local(mm)) {
-		struct tlb_flush_param p = { .pid = pid };
-		/* Ignores smp_processor_id() even if set. */
-		smp_call_function_many(mm_cpumask(mm),
-				       do_flush_tlb_mm_ipi, &p, 1);
-	}
-	_tlbil_pid(pid);
- no_context:
-	preempt_enable();
-}
-EXPORT_SYMBOL(flush_tlb_mm);
-
-void __flush_tlb_page(struct mm_struct *mm, unsigned long vmaddr,
-		      int tsize, int ind)
-{
-	struct cpumask *cpu_mask;
-	unsigned int pid;
-
-	/*
-	 * This function as well as __local_flush_tlb_page() must only be called
-	 * for user contexts.
-	 */
-	if (WARN_ON(!mm))
-		return;
-
-	preempt_disable();
-	pid = mm->context.id;
-	if (unlikely(pid == MMU_NO_CONTEXT))
-		goto bail;
-	cpu_mask = mm_cpumask(mm);
-	if (!mm_is_core_local(mm)) {
-		/* If broadcast tlbivax is supported, use it */
-		if (mmu_has_feature(MMU_FTR_USE_TLBIVAX_BCAST)) {
-			int lock = mmu_has_feature(MMU_FTR_LOCK_BCAST_INVAL);
-			if (lock)
-				raw_spin_lock(&tlbivax_lock);
-			_tlbivax_bcast(vmaddr, pid, tsize, ind);
-			if (lock)
-				raw_spin_unlock(&tlbivax_lock);
-			goto bail;
-		} else {
-			struct tlb_flush_param p = {
-				.pid = pid,
-				.addr = vmaddr,
-				.tsize = tsize,
-				.ind = ind,
-			};
-			/* Ignores smp_processor_id() even if set in cpu_mask */
-			smp_call_function_many(cpu_mask,
-					       do_flush_tlb_page_ipi, &p, 1);
-		}
-	}
-	_tlbil_va(vmaddr, pid, tsize, ind);
- bail:
-	preempt_enable();
-}
-
-void flush_tlb_page(struct vm_area_struct *vma, unsigned long vmaddr)
-{
-#ifdef CONFIG_HUGETLB_PAGE
-	if (vma && is_vm_hugetlb_page(vma))
-		flush_hugetlb_page(vma, vmaddr);
-#endif
-
-	__flush_tlb_page(vma ? vma->vm_mm : NULL, vmaddr,
-			 mmu_get_tsize(mmu_virtual_psize), 0);
-}
-EXPORT_SYMBOL(flush_tlb_page);
-
-#endif /* CONFIG_SMP */
-
-/*
- * Flush kernel TLB entries in the given range
- */
-#ifndef CONFIG_PPC_8xx
-void flush_tlb_kernel_range(unsigned long start, unsigned long end)
-{
-#ifdef CONFIG_SMP
-	preempt_disable();
-	smp_call_function(do_flush_tlb_mm_ipi, NULL, 1);
-	_tlbil_pid(0);
-	preempt_enable();
-#else
-	_tlbil_pid(0);
-#endif
-}
-EXPORT_SYMBOL(flush_tlb_kernel_range);
-#endif
-
-/*
- * Currently, for range flushing, we just do a full mm flush. This should
- * be optimized based on a threshold on the size of the range, since
- * some implementation can stack multiple tlbivax before a tlbsync but
- * for now, we keep it that way
- */
-void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
-		     unsigned long end)
-
-{
-	if (end - start == PAGE_SIZE && !(start & ~PAGE_MASK))
-		flush_tlb_page(vma, start);
-	else
-		flush_tlb_mm(vma->vm_mm);
-}
-EXPORT_SYMBOL(flush_tlb_range);
-
-void tlb_flush(struct mmu_gather *tlb)
-{
-	flush_tlb_mm(tlb->mm);
-}
-
-/*
- * Below are functions specific to the 64-bit variant of Book3E though that
- * may change in the future
- */
-
-#ifdef CONFIG_PPC64
-
 /*
  * Handling of virtual linear page tables or indirect TLB entries
  * flushing when PTE pages are freed
@@ -677,13 +359,3 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 	/* Finally limit subsequent allocations */
 	memblock_set_current_limit(first_memblock_base + ppc64_rma_size);
 }
-#else /* ! CONFIG_PPC64 */
-void __init early_init_mmu(void)
-{
-	unsigned long root = of_get_flat_dt_root();
-
-	if (IS_ENABLED(CONFIG_PPC_47x) && IS_ENABLED(CONFIG_SMP) &&
-	    of_get_flat_dt_prop(root, "cooperative-partition", NULL))
-		mmu_clear_feature(MMU_FTR_USE_TLBIVAX_BCAST);
-}
-#endif /* CONFIG_PPC64 */
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 03/23] powerpc/64e: Drop E500 ifdefs in 64-bit code
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 01/23] powerpc/64e: Remove unused IBM HTW code Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 02/23] powerpc/64e: Split out nohash Book3E 64-bit code Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 04/23] powerpc/64e: Drop MMU_FTR_TYPE_FSL_E checks " Christophe Leroy
                   ` (19 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

From: Michael Ellerman <mpe@ellerman.id.au>

All 64-bit Book3E have E500=y, so drop the unneeded ifdefs.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/tlb_64e.c | 12 ------------
 1 file changed, 12 deletions(-)

diff --git a/arch/powerpc/mm/nohash/tlb_64e.c b/arch/powerpc/mm/nohash/tlb_64e.c
index 7d5506d23eab..9db85ee9ba5b 100644
--- a/arch/powerpc/mm/nohash/tlb_64e.c
+++ b/arch/powerpc/mm/nohash/tlb_64e.c
@@ -85,7 +85,6 @@ static void __init setup_page_sizes(void)
 	unsigned int eptcfg;
 	int psize;
 
-#ifdef CONFIG_PPC_E500
 	unsigned int mmucfg = mfspr(SPRN_MMUCFG);
 	int fsl_mmu = mmu_has_feature(MMU_FTR_TYPE_FSL_E);
 
@@ -151,7 +150,6 @@ static void __init setup_page_sizes(void)
 
 		goto out;
 	}
-#endif
 out:
 	/* Cleanup array and print summary */
 	pr_info("MMU: Supported page sizes\n");
@@ -180,13 +178,11 @@ static void __init setup_mmu_htw(void)
 	 */
 
 	switch (book3e_htw_mode) {
-#ifdef CONFIG_PPC_E500
 	case PPC_HTW_E6500:
 		extlb_level_exc = EX_TLB_SIZE;
 		patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e);
 		patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e);
 		break;
-#endif
 	}
 	pr_info("MMU: Book3E HW tablewalk %s\n",
 		book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported");
@@ -217,7 +213,6 @@ static void early_init_this_mmu(void)
 	}
 	mtspr(SPRN_MAS4, mas4);
 
-#ifdef CONFIG_PPC_E500
 	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
 		unsigned int num_cams;
 		bool map = true;
@@ -238,7 +233,6 @@ static void early_init_this_mmu(void)
 			linear_map_top = map_mem_in_cams(linear_map_top,
 							 num_cams, false, true);
 	}
-#endif
 
 	/* A sync won't hurt us after mucking around with
 	 * the MMU configuration
@@ -270,7 +264,6 @@ static void __init early_init_mmu_global(void)
 	/* Look for HW tablewalk support */
 	setup_mmu_htw();
 
-#ifdef CONFIG_PPC_E500
 	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
 		if (book3e_htw_mode == PPC_HTW_NONE) {
 			extlb_level_exc = EX_TLB_SIZE;
@@ -279,7 +272,6 @@ static void __init early_init_mmu_global(void)
 				exc_instruction_tlb_miss_bolted_book3e);
 		}
 	}
-#endif
 
 	/* Set the global containing the top of the linear mapping
 	 * for use by the TLB miss code
@@ -291,7 +283,6 @@ static void __init early_init_mmu_global(void)
 
 static void __init early_mmu_set_memory_limit(void)
 {
-#ifdef CONFIG_PPC_E500
 	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
 		/*
 		 * Limit memory so we dont have linear faults.
@@ -302,7 +293,6 @@ static void __init early_mmu_set_memory_limit(void)
 		 */
 		memblock_enforce_memory_limit(linear_map_top);
 	}
-#endif
 
 	memblock_set_current_limit(linear_map_top);
 }
@@ -340,7 +330,6 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 	 * We crop it to the size of the first MEMBLOCK to
 	 * avoid going over total available memory just in case...
 	 */
-#ifdef CONFIG_PPC_E500
 	if (early_mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
 		unsigned long linear_sz;
 		unsigned int num_cams;
@@ -353,7 +342,6 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 
 		ppc64_rma_size = min_t(u64, linear_sz, 0x40000000);
 	} else
-#endif
 		ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
 
 	/* Finally limit subsequent allocations */
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 04/23] powerpc/64e: Drop MMU_FTR_TYPE_FSL_E checks in 64-bit code
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (2 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 03/23] powerpc/64e: Drop E500 ifdefs in " Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 05/23] powerpc/64e: Consolidate TLB miss handler patching Christophe Leroy
                   ` (18 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

From: Michael Ellerman <mpe@ellerman.id.au>

All 64-bit Book3E have MMU_FTR_TYPE_FSL_E, since A2 was removed, so
remove checks for it in 64-bit only code.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/setup_64.c   |  6 +-
 arch/powerpc/mm/nohash/tlb_64e.c | 97 ++++++++++++--------------------
 2 files changed, 38 insertions(+), 65 deletions(-)

diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index ae36a129789f..22f83fbbc762 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -696,11 +696,7 @@ __init u64 ppc64_bolted_size(void)
 {
 #ifdef CONFIG_PPC_BOOK3E_64
 	/* Freescale BookE bolts the entire linear mapping */
-	/* XXX: BookE ppc64_rma_limit setup seems to disagree? */
-	if (early_mmu_has_feature(MMU_FTR_TYPE_FSL_E))
-		return linear_map_top;
-	/* Other BookE, we assume the first GB is bolted */
-	return 1ul << 30;
+	return linear_map_top;
 #else
 	/* BookS radix, does not take faults on linear mapping */
 	if (early_radix_enabled())
diff --git a/arch/powerpc/mm/nohash/tlb_64e.c b/arch/powerpc/mm/nohash/tlb_64e.c
index 9db85ee9ba5b..21c4b2442fcf 100644
--- a/arch/powerpc/mm/nohash/tlb_64e.c
+++ b/arch/powerpc/mm/nohash/tlb_64e.c
@@ -86,9 +86,8 @@ static void __init setup_page_sizes(void)
 	int psize;
 
 	unsigned int mmucfg = mfspr(SPRN_MMUCFG);
-	int fsl_mmu = mmu_has_feature(MMU_FTR_TYPE_FSL_E);
 
-	if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
+	if ((mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V1) {
 		unsigned int tlb1cfg = mfspr(SPRN_TLB1CFG);
 		unsigned int min_pg, max_pg;
 
@@ -115,7 +114,7 @@ static void __init setup_page_sizes(void)
 		goto out;
 	}
 
-	if (fsl_mmu && (mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V2) {
+	if ((mmucfg & MMUCFG_MAVN) == MMUCFG_MAVN_V2) {
 		u32 tlb1cfg, tlb1ps;
 
 		tlb0cfg = mfspr(SPRN_TLB0CFG);
@@ -213,26 +212,24 @@ static void early_init_this_mmu(void)
 	}
 	mtspr(SPRN_MAS4, mas4);
 
-	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
-		unsigned int num_cams;
-		bool map = true;
+	unsigned int num_cams;
+	bool map = true;
 
-		/* use a quarter of the TLBCAM for bolted linear map */
-		num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
+	/* use a quarter of the TLBCAM for bolted linear map */
+	num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
 
-		/*
-		 * Only do the mapping once per core, or else the
-		 * transient mapping would cause problems.
-		 */
+	/*
+	 * Only do the mapping once per core, or else the
+	 * transient mapping would cause problems.
+	 */
 #ifdef CONFIG_SMP
-		if (hweight32(get_tensr()) > 1)
-			map = false;
+	if (hweight32(get_tensr()) > 1)
+		map = false;
 #endif
 
-		if (map)
-			linear_map_top = map_mem_in_cams(linear_map_top,
-							 num_cams, false, true);
-	}
+	if (map)
+		linear_map_top = map_mem_in_cams(linear_map_top,
+						 num_cams, false, true);
 
 	/* A sync won't hurt us after mucking around with
 	 * the MMU configuration
@@ -242,16 +239,10 @@ static void early_init_this_mmu(void)
 
 static void __init early_init_mmu_global(void)
 {
-	/* XXX This should be decided at runtime based on supported
-	 * page sizes in the TLB, but for now let's assume 16M is
-	 * always there and a good fit (which it probably is)
-	 *
+	/*
 	 * Freescale booke only supports 4K pages in TLB0, so use that.
 	 */
-	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E))
-		mmu_vmemmap_psize = MMU_PAGE_4K;
-	else
-		mmu_vmemmap_psize = MMU_PAGE_16M;
+	mmu_vmemmap_psize = MMU_PAGE_4K;
 
 	/* XXX This code only checks for TLB 0 capabilities and doesn't
 	 *     check what page size combos are supported by the HW. It
@@ -264,13 +255,10 @@ static void __init early_init_mmu_global(void)
 	/* Look for HW tablewalk support */
 	setup_mmu_htw();
 
-	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
-		if (book3e_htw_mode == PPC_HTW_NONE) {
-			extlb_level_exc = EX_TLB_SIZE;
-			patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e);
-			patch_exception(0x1e0,
-				exc_instruction_tlb_miss_bolted_book3e);
-		}
+	if (book3e_htw_mode == PPC_HTW_NONE) {
+		extlb_level_exc = EX_TLB_SIZE;
+		patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e);
+		patch_exception(0x1e0, exc_instruction_tlb_miss_bolted_book3e);
 	}
 
 	/* Set the global containing the top of the linear mapping
@@ -283,16 +271,14 @@ static void __init early_init_mmu_global(void)
 
 static void __init early_mmu_set_memory_limit(void)
 {
-	if (mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
-		/*
-		 * Limit memory so we dont have linear faults.
-		 * Unlike memblock_set_current_limit, which limits
-		 * memory available during early boot, this permanently
-		 * reduces the memory available to Linux.  We need to
-		 * do this because highmem is not supported on 64-bit.
-		 */
-		memblock_enforce_memory_limit(linear_map_top);
-	}
+	/*
+	 * Limit memory so we dont have linear faults.
+	 * Unlike memblock_set_current_limit, which limits
+	 * memory available during early boot, this permanently
+	 * reduces the memory available to Linux.  We need to
+	 * do this because highmem is not supported on 64-bit.
+	 */
+	memblock_enforce_memory_limit(linear_map_top);
 
 	memblock_set_current_limit(linear_map_top);
 }
@@ -313,12 +299,8 @@ void early_init_mmu_secondary(void)
 void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 				phys_addr_t first_memblock_size)
 {
-	/* On non-FSL Embedded 64-bit, we adjust the RMA size to match
-	 * the bolted TLB entry. We know for now that only 1G
-	 * entries are supported though that may eventually
-	 * change.
-	 *
-	 * on FSL Embedded 64-bit, usually all RAM is bolted, but with
+	/*
+	 * On FSL Embedded 64-bit, usually all RAM is bolted, but with
 	 * unusual memory sizes it's possible for some RAM to not be mapped
 	 * (such RAM is not used at all by Linux, since we don't support
 	 * highmem on 64-bit).  We limit ppc64_rma_size to what would be
@@ -330,19 +312,14 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
 	 * We crop it to the size of the first MEMBLOCK to
 	 * avoid going over total available memory just in case...
 	 */
-	if (early_mmu_has_feature(MMU_FTR_TYPE_FSL_E)) {
-		unsigned long linear_sz;
-		unsigned int num_cams;
-
-		/* use a quarter of the TLBCAM for bolted linear map */
-		num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
+	unsigned long linear_sz;
+	unsigned int num_cams;
 
-		linear_sz = map_mem_in_cams(first_memblock_size, num_cams,
-					    true, true);
+	/* use a quarter of the TLBCAM for bolted linear map */
+	num_cams = (mfspr(SPRN_TLB1CFG) & TLBnCFG_N_ENTRY) / 4;
 
-		ppc64_rma_size = min_t(u64, linear_sz, 0x40000000);
-	} else
-		ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
+	linear_sz = map_mem_in_cams(first_memblock_size, num_cams, true, true);
+	ppc64_rma_size = min_t(u64, linear_sz, 0x40000000);
 
 	/* Finally limit subsequent allocations */
 	memblock_set_current_limit(first_memblock_base + ppc64_rma_size);
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 05/23] powerpc/64e: Consolidate TLB miss handler patching
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (3 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 04/23] powerpc/64e: Drop MMU_FTR_TYPE_FSL_E checks " Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 06/23] powerpc/64e: Drop unused TLB miss handlers Christophe Leroy
                   ` (17 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

From: Michael Ellerman <mpe@ellerman.id.au>

The 64e TLB miss handler patching is done in setup_mmu_htw(), and then
again immediately afterward in early_init_mmu_global(). Consolidate it
into a single location.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/mm/nohash/tlb_64e.c | 38 +++++++++++++-------------------
 1 file changed, 15 insertions(+), 23 deletions(-)

diff --git a/arch/powerpc/mm/nohash/tlb_64e.c b/arch/powerpc/mm/nohash/tlb_64e.c
index 21c4b2442fcf..d83ecf466929 100644
--- a/arch/powerpc/mm/nohash/tlb_64e.c
+++ b/arch/powerpc/mm/nohash/tlb_64e.c
@@ -169,24 +169,6 @@ static void __init setup_page_sizes(void)
 	}
 }
 
-static void __init setup_mmu_htw(void)
-{
-	/*
-	 * If we want to use HW tablewalk, enable it by patching the TLB miss
-	 * handlers to branch to the one dedicated to it.
-	 */
-
-	switch (book3e_htw_mode) {
-	case PPC_HTW_E6500:
-		extlb_level_exc = EX_TLB_SIZE;
-		patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e);
-		patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e);
-		break;
-	}
-	pr_info("MMU: Book3E HW tablewalk %s\n",
-		book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported");
-}
-
 /*
  * Early initialization of the MMU TLB code
  */
@@ -252,15 +234,25 @@ static void __init early_init_mmu_global(void)
 	/* Look for supported page sizes */
 	setup_page_sizes();
 
-	/* Look for HW tablewalk support */
-	setup_mmu_htw();
-
-	if (book3e_htw_mode == PPC_HTW_NONE) {
-		extlb_level_exc = EX_TLB_SIZE;
+	/*
+	 * If we want to use HW tablewalk, enable it by patching the TLB miss
+	 * handlers to branch to the one dedicated to it.
+	 */
+	extlb_level_exc = EX_TLB_SIZE;
+	switch (book3e_htw_mode) {
+	case PPC_HTW_E6500:
+		patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e);
+		patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e);
+		break;
+	case PPC_HTW_NONE:
 		patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e);
 		patch_exception(0x1e0, exc_instruction_tlb_miss_bolted_book3e);
+		break;
 	}
 
+	pr_info("MMU: Book3E HW tablewalk %s\n",
+		book3e_htw_mode != PPC_HTW_NONE ? "enabled" : "not supported");
+
 	/* Set the global containing the top of the linear mapping
 	 * for use by the TLB miss code
 	 */
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 06/23] powerpc/64e: Drop unused TLB miss handlers
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (4 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 05/23] powerpc/64e: Consolidate TLB miss handler patching Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 07/23] mm: Define __pte_leaf_size() to also take a PMD entry Christophe Leroy
                   ` (16 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

From: Michael Ellerman <mpe@ellerman.id.au>

There are two possibilities for book3e_htw_mode, PPC_HTW_E6500 or
PPC_HTW_NONE.

The TLB miss handlers are patched to use, respectively:
  - exc_[data|indstruction]_tlb_miss_e6500_book3e
  - exc_[data|indstruction]_tlb_miss_bolted_book3e

Which means the default handlers are never used. Remove those, and use
the bolted handlers (PPC_HTW_NONE) by default.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/kernel/exceptions-64e.S |   4 +-
 arch/powerpc/mm/nohash/tlb_64e.c     |   4 -
 arch/powerpc/mm/nohash/tlb_low_64e.S | 226 ---------------------------
 3 files changed, 2 insertions(+), 232 deletions(-)

diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index dcf0591ad3c2..63f6b9f513a4 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -485,8 +485,8 @@ interrupt_base_book3e:					/* fake trap */
 	EXCEPTION_STUB(0x160, decrementer)		/* 0x0900 */
 	EXCEPTION_STUB(0x180, fixed_interval)		/* 0x0980 */
 	EXCEPTION_STUB(0x1a0, watchdog)			/* 0x09f0 */
-	EXCEPTION_STUB(0x1c0, data_tlb_miss)
-	EXCEPTION_STUB(0x1e0, instruction_tlb_miss)
+	EXCEPTION_STUB(0x1c0, data_tlb_miss_bolted)
+	EXCEPTION_STUB(0x1e0, instruction_tlb_miss_bolted)
 	EXCEPTION_STUB(0x200, altivec_unavailable)
 	EXCEPTION_STUB(0x220, altivec_assist)
 	EXCEPTION_STUB(0x260, perfmon)
diff --git a/arch/powerpc/mm/nohash/tlb_64e.c b/arch/powerpc/mm/nohash/tlb_64e.c
index d83ecf466929..053128a5636c 100644
--- a/arch/powerpc/mm/nohash/tlb_64e.c
+++ b/arch/powerpc/mm/nohash/tlb_64e.c
@@ -244,10 +244,6 @@ static void __init early_init_mmu_global(void)
 		patch_exception(0x1c0, exc_data_tlb_miss_e6500_book3e);
 		patch_exception(0x1e0, exc_instruction_tlb_miss_e6500_book3e);
 		break;
-	case PPC_HTW_NONE:
-		patch_exception(0x1c0, exc_data_tlb_miss_bolted_book3e);
-		patch_exception(0x1e0, exc_instruction_tlb_miss_bolted_book3e);
-		break;
 	}
 
 	pr_info("MMU: Book3E HW tablewalk %s\n",
diff --git a/arch/powerpc/mm/nohash/tlb_low_64e.S b/arch/powerpc/mm/nohash/tlb_low_64e.S
index b0eb3f7eaed1..a54e7d6c3d0b 100644
--- a/arch/powerpc/mm/nohash/tlb_low_64e.S
+++ b/arch/powerpc/mm/nohash/tlb_low_64e.S
@@ -511,232 +511,6 @@ itlb_miss_fault_e6500:
 	tlb_epilog_bolted
 	b	exc_instruction_storage_book3e
 
-/**********************************************************************
- *                                                                    *
- * TLB miss handling for Book3E with TLB reservation and HES support  *
- *                                                                    *
- **********************************************************************/
-
-
-/* Data TLB miss */
-	START_EXCEPTION(data_tlb_miss)
-	TLB_MISS_PROLOG
-
-	/* Now we handle the fault proper. We only save DEAR in normal
-	 * fault case since that's the only interesting values here.
-	 * We could probably also optimize by not saving SRR0/1 in the
-	 * linear mapping case but I'll leave that for later
-	 */
-	mfspr	r14,SPRN_ESR
-	mfspr	r16,SPRN_DEAR		/* get faulting address */
-	srdi	r15,r16,44		/* get region */
-	xoris	r15,r15,0xc
-	cmpldi	cr0,r15,0		/* linear mapping ? */
-	beq	tlb_load_linear		/* yes -> go to linear map load */
-	cmpldi	cr1,r15,1		/* vmalloc mapping ? */
-
-	/* The page tables are mapped virtually linear. At this point, though,
-	 * we don't know whether we are trying to fault in a first level
-	 * virtual address or a virtual page table address. We can get that
-	 * from bit 0x1 of the region ID which we have set for a page table
-	 */
-	andis.	r10,r15,0x1
-	bne-	virt_page_table_tlb_miss
-
-	std	r14,EX_TLB_ESR(r12);	/* save ESR */
-	std	r16,EX_TLB_DEAR(r12);	/* save DEAR */
-
-	 /* We need _PAGE_PRESENT and  _PAGE_ACCESSED set */
-	li	r11,_PAGE_PRESENT
-	oris	r11,r11,_PAGE_ACCESSED@h
-
-	/* We do the user/kernel test for the PID here along with the RW test
-	 */
-	srdi.	r15,r16,60		/* Check for user region */
-
-	/* We pre-test some combination of permissions to avoid double
-	 * faults:
-	 *
-	 * We move the ESR:ST bit into the position of _PAGE_BAP_SW in the PTE
-	 * ESR_ST   is 0x00800000
-	 * _PAGE_BAP_SW is 0x00000010
-	 * So the shift is >> 19. This tests for supervisor writeability.
-	 * If the page happens to be supervisor writeable and not user
-	 * writeable, we will take a new fault later, but that should be
-	 * a rare enough case.
-	 *
-	 * We also move ESR_ST in _PAGE_DIRTY position
-	 * _PAGE_DIRTY is 0x00001000 so the shift is >> 11
-	 *
-	 * MAS1 is preset for all we need except for TID that needs to
-	 * be cleared for kernel translations
-	 */
-	rlwimi	r11,r14,32-19,27,27
-	rlwimi	r11,r14,32-16,19,19
-	beq	normal_tlb_miss_user
-	/* XXX replace the RMW cycles with immediate loads + writes */
-1:	mfspr	r10,SPRN_MAS1
-	rlwinm	r10,r10,0,16,1		/* Clear TID */
-	mtspr	SPRN_MAS1,r10
-	beq+	cr1,normal_tlb_miss
-
-	/* We got a crappy address, just fault with whatever DEAR and ESR
-	 * are here
-	 */
-	TLB_MISS_EPILOG_ERROR
-	b	exc_data_storage_book3e
-
-/* Instruction TLB miss */
-	START_EXCEPTION(instruction_tlb_miss)
-	TLB_MISS_PROLOG
-
-	/* If we take a recursive fault, the second level handler may need
-	 * to know whether we are handling a data or instruction fault in
-	 * order to get to the right store fault handler. We provide that
-	 * info by writing a crazy value in ESR in our exception frame
-	 */
-	li	r14,-1	/* store to exception frame is done later */
-
-	/* Now we handle the fault proper. We only save DEAR in the non
-	 * linear mapping case since we know the linear mapping case will
-	 * not re-enter. We could indeed optimize and also not save SRR0/1
-	 * in the linear mapping case but I'll leave that for later
-	 *
-	 * Faulting address is SRR0 which is already in r16
-	 */
-	srdi	r15,r16,44		/* get region */
-	xoris	r15,r15,0xc
-	cmpldi	cr0,r15,0		/* linear mapping ? */
-	beq	tlb_load_linear		/* yes -> go to linear map load */
-	cmpldi	cr1,r15,1		/* vmalloc mapping ? */
-
-	/* We do the user/kernel test for the PID here along with the RW test
-	 */
-	li	r11,_PAGE_PRESENT|_PAGE_BAP_UX	/* Base perm */
-	oris	r11,r11,_PAGE_ACCESSED@h
-
-	srdi.	r15,r16,60			/* Check for user region */
-	std	r14,EX_TLB_ESR(r12)		/* write crazy -1 to frame */
-	beq	normal_tlb_miss_user
-
-	li	r11,_PAGE_PRESENT|_PAGE_BAP_SX	/* Base perm */
-	oris	r11,r11,_PAGE_ACCESSED@h
-	/* XXX replace the RMW cycles with immediate loads + writes */
-	mfspr	r10,SPRN_MAS1
-	rlwinm	r10,r10,0,16,1			/* Clear TID */
-	mtspr	SPRN_MAS1,r10
-	beq+	cr1,normal_tlb_miss
-
-	/* We got a crappy address, just fault */
-	TLB_MISS_EPILOG_ERROR
-	b	exc_instruction_storage_book3e
-
-/*
- * This is the guts of the first-level TLB miss handler for direct
- * misses. We are entered with:
- *
- * r16 = faulting address
- * r15 = region ID
- * r14 = crap (free to use)
- * r13 = PACA
- * r12 = TLB exception frame in PACA
- * r11 = PTE permission mask
- * r10 = crap (free to use)
- */
-normal_tlb_miss_user:
-#ifdef CONFIG_PPC_KUAP
-	mfspr	r14,SPRN_MAS1
-	rlwinm.	r14,r14,0,0x3fff0000
-	beq-	normal_tlb_miss_access_fault /* KUAP fault */
-#endif
-normal_tlb_miss:
-	/* So we first construct the page table address. We do that by
-	 * shifting the bottom of the address (not the region ID) by
-	 * PAGE_SHIFT-3, clearing the bottom 3 bits (get a PTE ptr) and
-	 * or'ing the fourth high bit.
-	 *
-	 * NOTE: For 64K pages, we do things slightly differently in
-	 * order to handle the weird page table format used by linux
-	 */
-	srdi	r15,r16,44
-	oris	r10,r15,0x1
-	rldicl	r14,r16,64-(PAGE_SHIFT-3),PAGE_SHIFT-3+4
-	sldi	r15,r10,44
-	clrrdi	r14,r14,19
-	or	r10,r15,r14
-
-	ld	r14,0(r10)
-
-finish_normal_tlb_miss:
-	/* Check if required permissions are met */
-	andc.	r15,r11,r14
-	bne-	normal_tlb_miss_access_fault
-
-	/* Now we build the MAS:
-	 *
-	 * MAS 0   :	Fully setup with defaults in MAS4 and TLBnCFG
-	 * MAS 1   :	Almost fully setup
-	 *               - PID already updated by caller if necessary
-	 *               - TSIZE need change if !base page size, not
-	 *                 yet implemented for now
-	 * MAS 2   :	Defaults not useful, need to be redone
-	 * MAS 3+7 :	Needs to be done
-	 *
-	 * TODO: mix up code below for better scheduling
-	 */
-	clrrdi	r10,r16,12		/* Clear low crap in EA */
-	rlwimi	r10,r14,32-19,27,31	/* Insert WIMGE */
-	mtspr	SPRN_MAS2,r10
-
-	/* Check page size, if not standard, update MAS1 */
-	rldicl	r10,r14,64-8,64-8
-	cmpldi	cr0,r10,BOOK3E_PAGESZ_4K
-	beq-	1f
-	mfspr	r11,SPRN_MAS1
-	rlwimi	r11,r14,31,21,24
-	rlwinm	r11,r11,0,21,19
-	mtspr	SPRN_MAS1,r11
-1:
-	/* Move RPN in position */
-	rldicr	r11,r14,64-(PTE_RPN_SHIFT-PAGE_SHIFT),63-PAGE_SHIFT
-	clrldi	r15,r11,12		/* Clear crap at the top */
-	rlwimi	r15,r14,32-8,22,25	/* Move in U bits */
-	rlwimi	r15,r14,32-2,26,31	/* Move in BAP bits */
-
-	/* Mask out SW and UW if !DIRTY (XXX optimize this !) */
-	andi.	r11,r14,_PAGE_DIRTY
-	bne	1f
-	li	r11,MAS3_SW|MAS3_UW
-	andc	r15,r15,r11
-1:
-	srdi	r16,r15,32
-	mtspr	SPRN_MAS3,r15
-	mtspr	SPRN_MAS7,r16
-
-	tlbwe
-
-normal_tlb_miss_done:
-	/* We don't bother with restoring DEAR or ESR since we know we are
-	 * level 0 and just going back to userland. They are only needed
-	 * if you are going to take an access fault
-	 */
-	TLB_MISS_EPILOG_SUCCESS
-	rfi
-
-normal_tlb_miss_access_fault:
-	/* We need to check if it was an instruction miss */
-	andi.	r10,r11,_PAGE_BAP_UX
-	bne	1f
-	ld	r14,EX_TLB_DEAR(r12)
-	ld	r15,EX_TLB_ESR(r12)
-	mtspr	SPRN_DEAR,r14
-	mtspr	SPRN_ESR,r15
-	TLB_MISS_EPILOG_ERROR
-	b	exc_data_storage_book3e
-1:	TLB_MISS_EPILOG_ERROR
-	b	exc_instruction_storage_book3e
-
-
 /*
  * This is the guts of the second-level TLB miss handler for direct
  * misses. We are entered with:
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 07/23] mm: Define __pte_leaf_size() to also take a PMD entry
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (5 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 06/23] powerpc/64e: Drop unused TLB miss handlers Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 08/23] mm: Provide mm_struct and address to huge_ptep_get() Christophe Leroy
                   ` (15 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

On powerpc 8xx, when a page is 8M size, the information is in the PMD
entry. So allow architectures to provide __pte_leaf_size() instead of
pte_leaf_size() and provide the PMD entry to that function.

When __pte_leaf_size() is not defined, define it as a pte_leaf_size()
so that architectures not interested in the PMD arguments are not
impacted.

Only define a default pte_leaf_size() when __pte_leaf_size() is not
defined to make sure nobody adds new calls to pte_leaf_size() in the
core.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
---
v3: Don't change pte_leaf_size() to not impact other architectures
---
 include/linux/pgtable.h | 3 +++
 kernel/events/core.c    | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index 2f32eaccf0b9..2a6a3cccfc36 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -1907,9 +1907,12 @@ typedef unsigned int pgtbl_mod_mask;
 #ifndef pmd_leaf_size
 #define pmd_leaf_size(x) PMD_SIZE
 #endif
+#ifndef __pte_leaf_size
 #ifndef pte_leaf_size
 #define pte_leaf_size(x) PAGE_SIZE
 #endif
+#define __pte_leaf_size(x,y) pte_leaf_size(y)
+#endif
 
 /*
  * We always define pmd_pfn for all archs as it's used in lots of generic
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 8f908f077935..b2ca11bdc11e 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -7609,7 +7609,7 @@ static u64 perf_get_pgtable_size(struct mm_struct *mm, unsigned long addr)
 
 	pte = ptep_get_lockless(ptep);
 	if (pte_present(pte))
-		size = pte_leaf_size(pte);
+		size = __pte_leaf_size(pmd, pte);
 	pte_unmap(ptep);
 #endif /* CONFIG_HAVE_GUP_FAST */
 
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 08/23] mm: Provide mm_struct and address to huge_ptep_get()
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (6 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 07/23] mm: Define __pte_leaf_size() to also take a PMD entry Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 09/23] powerpc/mm: Remove _PAGE_PSIZE Christophe Leroy
                   ` (14 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

On powerpc 8xx huge_ptep_get() will need to know whether the given
ptep is a PTE entry or a PMD entry. This cannot be known with the
PMD entry itself because there is no easy way to know it from the
content of the entry.

So huge_ptep_get() will need to know either the size of the page
or get the pmd.

In order to be consistent with huge_ptep_get_and_clear(), give
mm and address to huge_ptep_get().

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
---
v2: Add missing changes in arch implementations
v3: Fixed a comment in ARM and missing changes in S390
v4: Fix missing or bad changes in mm/hugetlb.c and rebased on v6.10-rc1
v5: Fix vma->mm to vma->vm_mm
---
 arch/arm/include/asm/hugetlb-3level.h |  4 +--
 arch/arm64/include/asm/hugetlb.h      |  2 +-
 arch/arm64/mm/hugetlbpage.c           |  2 +-
 arch/riscv/include/asm/hugetlb.h      |  2 +-
 arch/riscv/mm/hugetlbpage.c           |  2 +-
 arch/s390/include/asm/hugetlb.h       |  4 +--
 arch/s390/mm/hugetlbpage.c            |  4 +--
 fs/hugetlbfs/inode.c                  |  2 +-
 fs/proc/task_mmu.c                    | 10 +++---
 fs/userfaultfd.c                      |  2 +-
 include/asm-generic/hugetlb.h         |  2 +-
 include/linux/swapops.h               |  4 +--
 mm/damon/vaddr.c                      |  6 ++--
 mm/gup.c                              |  2 +-
 mm/hmm.c                              |  2 +-
 mm/hugetlb.c                          | 44 +++++++++++++--------------
 mm/memory-failure.c                   |  2 +-
 mm/mempolicy.c                        |  2 +-
 mm/migrate.c                          |  4 +--
 mm/mincore.c                          |  2 +-
 mm/userfaultfd.c                      |  2 +-
 21 files changed, 53 insertions(+), 53 deletions(-)

diff --git a/arch/arm/include/asm/hugetlb-3level.h b/arch/arm/include/asm/hugetlb-3level.h
index a30be5505793..87d48e2d90ad 100644
--- a/arch/arm/include/asm/hugetlb-3level.h
+++ b/arch/arm/include/asm/hugetlb-3level.h
@@ -13,12 +13,12 @@
 
 /*
  * If our huge pte is non-zero then mark the valid bit.
- * This allows pte_present(huge_ptep_get(ptep)) to return true for non-zero
+ * This allows pte_present(huge_ptep_get(mm,addr,ptep)) to return true for non-zero
  * ptes.
  * (The valid bit is automatically cleared by set_pte_at for PROT_NONE ptes).
  */
 #define __HAVE_ARCH_HUGE_PTEP_GET
-static inline pte_t huge_ptep_get(pte_t *ptep)
+static inline pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	pte_t retval = *ptep;
 	if (pte_val(retval))
diff --git a/arch/arm64/include/asm/hugetlb.h b/arch/arm64/include/asm/hugetlb.h
index 3954cbd2ff56..293f880865e8 100644
--- a/arch/arm64/include/asm/hugetlb.h
+++ b/arch/arm64/include/asm/hugetlb.h
@@ -46,7 +46,7 @@ extern pte_t huge_ptep_clear_flush(struct vm_area_struct *vma,
 extern void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
 			   pte_t *ptep, unsigned long sz);
 #define __HAVE_ARCH_HUGE_PTEP_GET
-extern pte_t huge_ptep_get(pte_t *ptep);
+extern pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
 
 void __init arm64_hugetlb_cma_reserve(void);
 
diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
index 3f09ac73cce3..5f1e2103888b 100644
--- a/arch/arm64/mm/hugetlbpage.c
+++ b/arch/arm64/mm/hugetlbpage.c
@@ -127,7 +127,7 @@ static inline int num_contig_ptes(unsigned long size, size_t *pgsize)
 	return contig_ptes;
 }
 
-pte_t huge_ptep_get(pte_t *ptep)
+pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	int ncontig, i;
 	size_t pgsize;
diff --git a/arch/riscv/include/asm/hugetlb.h b/arch/riscv/include/asm/hugetlb.h
index b1ce97a9dbfc..faf3624d8057 100644
--- a/arch/riscv/include/asm/hugetlb.h
+++ b/arch/riscv/include/asm/hugetlb.h
@@ -44,7 +44,7 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 			       pte_t pte, int dirty);
 
 #define __HAVE_ARCH_HUGE_PTEP_GET
-pte_t huge_ptep_get(pte_t *ptep);
+pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
 
 pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags);
 #define arch_make_huge_pte arch_make_huge_pte
diff --git a/arch/riscv/mm/hugetlbpage.c b/arch/riscv/mm/hugetlbpage.c
index 0ebd968b33c9..42314f093922 100644
--- a/arch/riscv/mm/hugetlbpage.c
+++ b/arch/riscv/mm/hugetlbpage.c
@@ -3,7 +3,7 @@
 #include <linux/err.h>
 
 #ifdef CONFIG_RISCV_ISA_SVNAPOT
-pte_t huge_ptep_get(pte_t *ptep)
+pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	unsigned long pte_num;
 	int i;
diff --git a/arch/s390/include/asm/hugetlb.h b/arch/s390/include/asm/hugetlb.h
index ce5f4fe8be4d..cf1b5d6fb1a6 100644
--- a/arch/s390/include/asm/hugetlb.h
+++ b/arch/s390/include/asm/hugetlb.h
@@ -19,7 +19,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 		     pte_t *ptep, pte_t pte, unsigned long sz);
 void __set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 		     pte_t *ptep, pte_t pte);
-pte_t huge_ptep_get(pte_t *ptep);
+pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
 			      unsigned long addr, pte_t *ptep);
 
@@ -64,7 +64,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 					     unsigned long addr, pte_t *ptep,
 					     pte_t pte, int dirty)
 {
-	int changed = !pte_same(huge_ptep_get(ptep), pte);
+	int changed = !pte_same(huge_ptep_get(vma->vm_mm, addr, ptep), pte);
 	if (changed) {
 		huge_ptep_get_and_clear(vma->vm_mm, addr, ptep);
 		__set_huge_pte_at(vma->vm_mm, addr, ptep, pte);
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index 2675aab4acc7..1be481672f4a 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -169,7 +169,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
 	__set_huge_pte_at(mm, addr, ptep, pte);
 }
 
-pte_t huge_ptep_get(pte_t *ptep)
+pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	return __rste_to_pte(pte_val(*ptep));
 }
@@ -177,7 +177,7 @@ pte_t huge_ptep_get(pte_t *ptep)
 pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
 			      unsigned long addr, pte_t *ptep)
 {
-	pte_t pte = huge_ptep_get(ptep);
+	pte_t pte = huge_ptep_get(mm, addr, ptep);
 	pmd_t *pmdp = (pmd_t *) ptep;
 	pud_t *pudp = (pud_t *) ptep;
 
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index c34faef62daf..8d7b3d9c5a43 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -422,7 +422,7 @@ static bool hugetlb_vma_maps_page(struct vm_area_struct *vma,
 	if (!ptep)
 		return false;
 
-	pte = huge_ptep_get(ptep);
+	pte = huge_ptep_get(vma->vm_mm, addr, ptep);
 	if (huge_pte_none(pte) || !pte_present(pte))
 		return false;
 
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index d99a390a0f41..90ad9df8ea73 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1013,7 +1013,7 @@ static int smaps_hugetlb_range(pte_t *pte, unsigned long hmask,
 {
 	struct mem_size_stats *mss = walk->private;
 	struct vm_area_struct *vma = walk->vma;
-	pte_t ptent = huge_ptep_get(pte);
+	pte_t ptent = huge_ptep_get(walk->mm, addr, pte);
 	struct folio *folio = NULL;
 	bool present = false;
 
@@ -1882,7 +1882,7 @@ static int pagemap_hugetlb_range(pte_t *ptep, unsigned long hmask,
 	if (vma->vm_flags & VM_SOFTDIRTY)
 		flags |= PM_SOFT_DIRTY;
 
-	pte = huge_ptep_get(ptep);
+	pte = huge_ptep_get(walk->mm, addr, ptep);
 	if (pte_present(pte)) {
 		struct folio *folio = page_folio(pte_page(pte));
 
@@ -2571,7 +2571,7 @@ static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask,
 	if (~p->arg.flags & PM_SCAN_WP_MATCHING) {
 		/* Go the short route when not write-protecting pages. */
 
-		pte = huge_ptep_get(ptep);
+		pte = huge_ptep_get(walk->mm, start, ptep);
 		categories = p->cur_vma_category | pagemap_hugetlb_category(pte);
 
 		if (!pagemap_scan_is_interesting_page(categories, p))
@@ -2583,7 +2583,7 @@ static int pagemap_scan_hugetlb_entry(pte_t *ptep, unsigned long hmask,
 	i_mmap_lock_write(vma->vm_file->f_mapping);
 	ptl = huge_pte_lock(hstate_vma(vma), vma->vm_mm, ptep);
 
-	pte = huge_ptep_get(ptep);
+	pte = huge_ptep_get(walk->mm, start, ptep);
 	categories = p->cur_vma_category | pagemap_hugetlb_category(pte);
 
 	if (!pagemap_scan_is_interesting_page(categories, p))
@@ -2979,7 +2979,7 @@ static int gather_pte_stats(pmd_t *pmd, unsigned long addr,
 static int gather_hugetlb_stats(pte_t *pte, unsigned long hmask,
 		unsigned long addr, unsigned long end, struct mm_walk *walk)
 {
-	pte_t huge_pte = huge_ptep_get(pte);
+	pte_t huge_pte = huge_ptep_get(walk->mm, addr, pte);
 	struct numa_maps *md;
 	struct page *page;
 
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 17e409ceaa33..27a3e9285fbf 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -257,7 +257,7 @@ static inline bool userfaultfd_huge_must_wait(struct userfaultfd_ctx *ctx,
 		goto out;
 
 	ret = false;
-	pte = huge_ptep_get(ptep);
+	pte = huge_ptep_get(vma->vm_mm, vmf->address, ptep);
 
 	/*
 	 * Lockless access: we're in a wait_event so it's ok if it
diff --git a/include/asm-generic/hugetlb.h b/include/asm-generic/hugetlb.h
index 6dcf4d576970..594d5905f615 100644
--- a/include/asm-generic/hugetlb.h
+++ b/include/asm-generic/hugetlb.h
@@ -144,7 +144,7 @@ static inline int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 #endif
 
 #ifndef __HAVE_ARCH_HUGE_PTEP_GET
-static inline pte_t huge_ptep_get(pte_t *ptep)
+static inline pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 {
 	return ptep_get(ptep);
 }
diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index a5c560a2f8c2..cb468e418ea1 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -334,7 +334,7 @@ static inline bool is_migration_entry_dirty(swp_entry_t entry)
 
 extern void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
 					unsigned long address);
-extern void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *pte);
+extern void migration_entry_wait_huge(struct vm_area_struct *vma, unsigned long addr, pte_t *pte);
 #else  /* CONFIG_MIGRATION */
 static inline swp_entry_t make_readable_migration_entry(pgoff_t offset)
 {
@@ -359,7 +359,7 @@ static inline int is_migration_entry(swp_entry_t swp)
 static inline void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
 					unsigned long address) { }
 static inline void migration_entry_wait_huge(struct vm_area_struct *vma,
-					pte_t *pte) { }
+					     unsigned long addr, pte_t *pte) { }
 static inline int is_writable_migration_entry(swp_entry_t entry)
 {
 	return 0;
diff --git a/mm/damon/vaddr.c b/mm/damon/vaddr.c
index 381559e4a1fa..58829baf8b5d 100644
--- a/mm/damon/vaddr.c
+++ b/mm/damon/vaddr.c
@@ -339,7 +339,7 @@ static void damon_hugetlb_mkold(pte_t *pte, struct mm_struct *mm,
 				struct vm_area_struct *vma, unsigned long addr)
 {
 	bool referenced = false;
-	pte_t entry = huge_ptep_get(pte);
+	pte_t entry = huge_ptep_get(mm, addr, pte);
 	struct folio *folio = pfn_folio(pte_pfn(entry));
 	unsigned long psize = huge_page_size(hstate_vma(vma));
 
@@ -373,7 +373,7 @@ static int damon_mkold_hugetlb_entry(pte_t *pte, unsigned long hmask,
 	pte_t entry;
 
 	ptl = huge_pte_lock(h, walk->mm, pte);
-	entry = huge_ptep_get(pte);
+	entry = huge_ptep_get(walk->mm, addr, pte);
 	if (!pte_present(entry))
 		goto out;
 
@@ -509,7 +509,7 @@ static int damon_young_hugetlb_entry(pte_t *pte, unsigned long hmask,
 	pte_t entry;
 
 	ptl = huge_pte_lock(h, walk->mm, pte);
-	entry = huge_ptep_get(pte);
+	entry = huge_ptep_get(walk->mm, addr, pte);
 	if (!pte_present(entry))
 		goto out;
 
diff --git a/mm/gup.c b/mm/gup.c
index 0faf07b2c51d..aaf6ef4e28ee 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -508,7 +508,7 @@ static int gup_hugepte(struct vm_area_struct *vma, pte_t *ptep, unsigned long sz
 	if (pte_end < end)
 		end = pte_end;
 
-	pte = huge_ptep_get(ptep);
+	pte = huge_ptep_get(vma->vm_mm, addr, ptep);
 
 	if (!pte_access_permitted(pte, flags & FOLL_WRITE))
 		return 0;
diff --git a/mm/hmm.c b/mm/hmm.c
index 93aebd9cc130..7e0229ae4a5a 100644
--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -480,7 +480,7 @@ static int hmm_vma_walk_hugetlb_entry(pte_t *pte, unsigned long hmask,
 	pte_t entry;
 
 	ptl = huge_pte_lock(hstate_vma(vma), walk->mm, pte);
-	entry = huge_ptep_get(pte);
+	entry = huge_ptep_get(walk->mm, addr, pte);
 
 	i = (start - range->start) >> PAGE_SHIFT;
 	pfn_req_flags = range->hmm_pfns[i];
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 0a69e194b517..61847f799b6a 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -5286,7 +5286,7 @@ static void set_huge_ptep_writable(struct vm_area_struct *vma,
 {
 	pte_t entry;
 
-	entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(ptep)));
+	entry = huge_pte_mkwrite(huge_pte_mkdirty(huge_ptep_get(vma->vm_mm, address, ptep)));
 	if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1))
 		update_mmu_cache(vma, address, ptep);
 }
@@ -5394,7 +5394,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 		dst_ptl = huge_pte_lock(h, dst, dst_pte);
 		src_ptl = huge_pte_lockptr(h, src, src_pte);
 		spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
-		entry = huge_ptep_get(src_pte);
+		entry = huge_ptep_get(src_vma->vm_mm, addr, src_pte);
 again:
 		if (huge_pte_none(entry)) {
 			/*
@@ -5432,7 +5432,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 				set_huge_pte_at(dst, addr, dst_pte,
 						make_pte_marker(marker), sz);
 		} else {
-			entry = huge_ptep_get(src_pte);
+			entry = huge_ptep_get(src_vma->vm_mm, addr, src_pte);
 			pte_folio = page_folio(pte_page(entry));
 			folio_get(pte_folio);
 
@@ -5473,7 +5473,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 				dst_ptl = huge_pte_lock(h, dst, dst_pte);
 				src_ptl = huge_pte_lockptr(h, src, src_pte);
 				spin_lock_nested(src_ptl, SINGLE_DEPTH_NESTING);
-				entry = huge_ptep_get(src_pte);
+				entry = huge_ptep_get(src_vma->vm_mm, addr, src_pte);
 				if (!pte_same(src_pte_old, entry)) {
 					restore_reserve_on_error(h, dst_vma, addr,
 								new_folio);
@@ -5583,7 +5583,7 @@ int move_hugetlb_page_tables(struct vm_area_struct *vma,
 			new_addr |= last_addr_mask;
 			continue;
 		}
-		if (huge_pte_none(huge_ptep_get(src_pte)))
+		if (huge_pte_none(huge_ptep_get(mm, old_addr, src_pte)))
 			continue;
 
 		if (huge_pmd_unshare(mm, vma, old_addr, src_pte)) {
@@ -5656,7 +5656,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
 			continue;
 		}
 
-		pte = huge_ptep_get(ptep);
+		pte = huge_ptep_get(mm, address, ptep);
 		if (huge_pte_none(pte)) {
 			spin_unlock(ptl);
 			continue;
@@ -5905,7 +5905,7 @@ static vm_fault_t hugetlb_wp(struct folio *pagecache_folio,
 	struct vm_area_struct *vma = vmf->vma;
 	struct mm_struct *mm = vma->vm_mm;
 	const bool unshare = vmf->flags & FAULT_FLAG_UNSHARE;
-	pte_t pte = huge_ptep_get(vmf->pte);
+	pte_t pte = huge_ptep_get(mm, vmf->address, vmf->pte);
 	struct hstate *h = hstate_vma(vma);
 	struct folio *old_folio;
 	struct folio *new_folio;
@@ -6026,7 +6026,7 @@ static vm_fault_t hugetlb_wp(struct folio *pagecache_folio,
 			vmf->pte = hugetlb_walk(vma, vmf->address,
 					huge_page_size(h));
 			if (likely(vmf->pte &&
-				   pte_same(huge_ptep_get(vmf->pte), pte)))
+				   pte_same(huge_ptep_get(mm, vmf->address, vmf->pte), pte)))
 				goto retry_avoidcopy;
 			/*
 			 * race occurs while re-acquiring page table
@@ -6064,7 +6064,7 @@ static vm_fault_t hugetlb_wp(struct folio *pagecache_folio,
 	 */
 	spin_lock(vmf->ptl);
 	vmf->pte = hugetlb_walk(vma, vmf->address, huge_page_size(h));
-	if (likely(vmf->pte && pte_same(huge_ptep_get(vmf->pte), pte))) {
+	if (likely(vmf->pte && pte_same(huge_ptep_get(mm, vmf->address, vmf->pte), pte))) {
 		pte_t newpte = make_huge_pte(vma, &new_folio->page, !unshare);
 
 		/* Break COW or unshare */
@@ -6165,14 +6165,14 @@ static inline vm_fault_t hugetlb_handle_userfault(struct vm_fault *vmf,
  * Recheck pte with pgtable lock.  Returns true if pte didn't change, or
  * false if pte changed or is changing.
  */
-static bool hugetlb_pte_stable(struct hstate *h, struct mm_struct *mm,
+static bool hugetlb_pte_stable(struct hstate *h, struct mm_struct *mm, unsigned long addr,
 			       pte_t *ptep, pte_t old_pte)
 {
 	spinlock_t *ptl;
 	bool same;
 
 	ptl = huge_pte_lock(h, mm, ptep);
-	same = pte_same(huge_ptep_get(ptep), old_pte);
+	same = pte_same(huge_ptep_get(mm, addr, ptep), old_pte);
 	spin_unlock(ptl);
 
 	return same;
@@ -6233,7 +6233,7 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 			 * never happen on the page after UFFDIO_COPY has
 			 * correctly installed the page and returned.
 			 */
-			if (!hugetlb_pte_stable(h, mm, vmf->pte, vmf->orig_pte)) {
+			if (!hugetlb_pte_stable(h, mm, vmf->address, vmf->pte, vmf->orig_pte)) {
 				ret = 0;
 				goto out;
 			}
@@ -6262,7 +6262,7 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 			 * here.  Before returning error, get ptl and make
 			 * sure there really is no pte entry.
 			 */
-			if (hugetlb_pte_stable(h, mm, vmf->pte, vmf->orig_pte))
+			if (hugetlb_pte_stable(h, mm, vmf->address, vmf->pte, vmf->orig_pte))
 				ret = vmf_error(PTR_ERR(folio));
 			else
 				ret = 0;
@@ -6311,7 +6311,7 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 			folio_unlock(folio);
 			folio_put(folio);
 			/* See comment in userfaultfd_missing() block above */
-			if (!hugetlb_pte_stable(h, mm, vmf->pte, vmf->orig_pte)) {
+			if (!hugetlb_pte_stable(h, mm, vmf->address, vmf->pte, vmf->orig_pte)) {
 				ret = 0;
 				goto out;
 			}
@@ -6338,7 +6338,7 @@ static vm_fault_t hugetlb_no_page(struct address_space *mapping,
 	vmf->ptl = huge_pte_lock(h, mm, vmf->pte);
 	ret = 0;
 	/* If pte changed from under us, retry */
-	if (!pte_same(huge_ptep_get(vmf->pte), vmf->orig_pte))
+	if (!pte_same(huge_ptep_get(mm, vmf->address, vmf->pte), vmf->orig_pte))
 		goto backout;
 
 	if (anon_rmap)
@@ -6459,7 +6459,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 		return VM_FAULT_OOM;
 	}
 
-	vmf.orig_pte = huge_ptep_get(vmf.pte);
+	vmf.orig_pte = huge_ptep_get(mm, vmf.address, vmf.pte);
 	if (huge_pte_none_mostly(vmf.orig_pte)) {
 		if (is_pte_marker(vmf.orig_pte)) {
 			pte_marker marker =
@@ -6500,7 +6500,7 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 			 * be released there.
 			 */
 			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
-			migration_entry_wait_huge(vma, vmf.pte);
+			migration_entry_wait_huge(vma, vmf.address, vmf.pte);
 			return 0;
 		} else if (unlikely(is_hugetlb_entry_hwpoisoned(vmf.orig_pte)))
 			ret = VM_FAULT_HWPOISON_LARGE |
@@ -6533,11 +6533,11 @@ vm_fault_t hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	vmf.ptl = huge_pte_lock(h, mm, vmf.pte);
 
 	/* Check for a racing update before calling hugetlb_wp() */
-	if (unlikely(!pte_same(vmf.orig_pte, huge_ptep_get(vmf.pte))))
+	if (unlikely(!pte_same(vmf.orig_pte, huge_ptep_get(mm, vmf.address, vmf.pte))))
 		goto out_ptl;
 
 	/* Handle userfault-wp first, before trying to lock more pages */
-	if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(vmf.pte)) &&
+	if (userfaultfd_wp(vma) && huge_pte_uffd_wp(huge_ptep_get(mm, vmf.address, vmf.pte)) &&
 	    (flags & FAULT_FLAG_WRITE) && !huge_pte_write(vmf.orig_pte)) {
 		if (!userfaultfd_wp_async(vma)) {
 			spin_unlock(vmf.ptl);
@@ -6665,7 +6665,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
 		ptl = huge_pte_lock(h, dst_mm, dst_pte);
 
 		/* Don't overwrite any existing PTEs (even markers) */
-		if (!huge_pte_none(huge_ptep_get(dst_pte))) {
+		if (!huge_pte_none(huge_ptep_get(dst_mm, dst_addr, dst_pte))) {
 			spin_unlock(ptl);
 			return -EEXIST;
 		}
@@ -6801,7 +6801,7 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_pte,
 	 * page backing it, then access the page.
 	 */
 	ret = -EEXIST;
-	if (!huge_pte_none_mostly(huge_ptep_get(dst_pte)))
+	if (!huge_pte_none_mostly(huge_ptep_get(dst_mm, dst_addr, dst_pte)))
 		goto out_release_unlock;
 
 	if (folio_in_pagecache)
@@ -6922,7 +6922,7 @@ long hugetlb_change_protection(struct vm_area_struct *vma,
 			address |= last_addr_mask;
 			continue;
 		}
-		pte = huge_ptep_get(ptep);
+		pte = huge_ptep_get(mm, address, ptep);
 		if (unlikely(is_hugetlb_entry_hwpoisoned(pte))) {
 			/* Nothing to do. */
 		} else if (unlikely(is_hugetlb_entry_migration(pte))) {
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index ac661a0e967c..0cb1b7bea9a5 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -835,7 +835,7 @@ static int hwpoison_hugetlb_range(pte_t *ptep, unsigned long hmask,
 			    struct mm_walk *walk)
 {
 	struct hwpoison_walk *hwp = walk->private;
-	pte_t pte = huge_ptep_get(ptep);
+	pte_t pte = huge_ptep_get(walk->mm, addr, ptep);
 	struct hstate *h = hstate_vma(walk->vma);
 
 	return check_hwpoisoned_entry(pte, addr, huge_page_shift(h),
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index f73acb01ad45..f8703feb68b7 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -624,7 +624,7 @@ static int queue_folios_hugetlb(pte_t *pte, unsigned long hmask,
 	pte_t entry;
 
 	ptl = huge_pte_lock(hstate_vma(walk->vma), walk->mm, pte);
-	entry = huge_ptep_get(pte);
+	entry = huge_ptep_get(walk->mm, addr, pte);
 	if (!pte_present(entry)) {
 		if (unlikely(is_hugetlb_entry_migration(entry)))
 			qp->nr_failed++;
diff --git a/mm/migrate.c b/mm/migrate.c
index c64d867f239d..e10d2445fbd8 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -338,14 +338,14 @@ void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
  *
  * This function will release the vma lock before returning.
  */
-void migration_entry_wait_huge(struct vm_area_struct *vma, pte_t *ptep)
+void migration_entry_wait_huge(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
 {
 	spinlock_t *ptl = huge_pte_lockptr(hstate_vma(vma), vma->vm_mm, ptep);
 	pte_t pte;
 
 	hugetlb_vma_assert_locked(vma);
 	spin_lock(ptl);
-	pte = huge_ptep_get(ptep);
+	pte = huge_ptep_get(vma->vm_mm, addr, ptep);
 
 	if (unlikely(!is_hugetlb_entry_migration(pte))) {
 		spin_unlock(ptl);
diff --git a/mm/mincore.c b/mm/mincore.c
index e31cf1bde614..d6bd19e520fc 100644
--- a/mm/mincore.c
+++ b/mm/mincore.c
@@ -33,7 +33,7 @@ static int mincore_hugetlb(pte_t *pte, unsigned long hmask, unsigned long addr,
 	 * Hugepages under user process are always in RAM and never
 	 * swapped out, but theoretically it needs to be checked.
 	 */
-	present = pte && !huge_pte_none_mostly(huge_ptep_get(pte));
+	present = pte && !huge_pte_none_mostly(huge_ptep_get(walk->mm, addr, pte));
 	for (; addr != end; vec++, addr += PAGE_SIZE)
 		*vec = present;
 	walk->private = vec;
diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c
index 8dedaec00486..e54e5c8907fa 100644
--- a/mm/userfaultfd.c
+++ b/mm/userfaultfd.c
@@ -587,7 +587,7 @@ static __always_inline ssize_t mfill_atomic_hugetlb(
 		}
 
 		if (!uffd_flags_mode_is(flags, MFILL_ATOMIC_CONTINUE) &&
-		    !huge_pte_none_mostly(huge_ptep_get(dst_pte))) {
+		    !huge_pte_none_mostly(huge_ptep_get(dst_mm, dst_addr, dst_pte))) {
 			err = -EEXIST;
 			hugetlb_vma_unlock_read(dst_vma);
 			mutex_unlock(&hugetlb_fault_mutex_table[hash]);
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 09/23] powerpc/mm: Remove _PAGE_PSIZE
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (7 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 08/23] mm: Provide mm_struct and address to huge_ptep_get() Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 10/23] powerpc/mm: Fix __find_linux_pte() on 32 bits with PMD leaf entries Christophe Leroy
                   ` (13 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

_PAGE_PSIZE macro is never used outside the place it is defined
and is used only on 8xx and e500.

Remove indirection, remove it and use its content directly.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
---
v6: Removed the change to pte-40x.h to avoid conflict with the removal of 40x
---
 arch/powerpc/include/asm/nohash/32/pte-44x.h  | 3 ---
 arch/powerpc/include/asm/nohash/32/pte-85xx.h | 3 ---
 arch/powerpc/include/asm/nohash/32/pte-8xx.h  | 5 ++---
 arch/powerpc/include/asm/nohash/pte-e500.h    | 4 +---
 4 files changed, 3 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/include/asm/nohash/32/pte-44x.h b/arch/powerpc/include/asm/nohash/32/pte-44x.h
index 851813725237..da0469928273 100644
--- a/arch/powerpc/include/asm/nohash/32/pte-44x.h
+++ b/arch/powerpc/include/asm/nohash/32/pte-44x.h
@@ -75,9 +75,6 @@
 #define _PAGE_NO_CACHE	0x00000400		/* H: I bit */
 #define _PAGE_WRITETHRU	0x00000800		/* H: W bit */
 
-/* No page size encoding in the linux PTE */
-#define _PAGE_PSIZE		0
-
 /* TODO: Add large page lowmem mapping support */
 #define _PMD_PRESENT	0
 #define _PMD_PRESENT_MASK (PAGE_MASK)
diff --git a/arch/powerpc/include/asm/nohash/32/pte-85xx.h b/arch/powerpc/include/asm/nohash/32/pte-85xx.h
index 653a342d3b25..14d64b4f3f14 100644
--- a/arch/powerpc/include/asm/nohash/32/pte-85xx.h
+++ b/arch/powerpc/include/asm/nohash/32/pte-85xx.h
@@ -31,9 +31,6 @@
 #define _PAGE_WRITETHRU	0x00400	/* H: W bit */
 #define _PAGE_SPECIAL	0x00800 /* S: Special page */
 
-/* No page size encoding in the linux PTE */
-#define _PAGE_PSIZE		0
-
 #define _PMD_PRESENT	0
 #define _PMD_PRESENT_MASK (PAGE_MASK)
 #define _PMD_BAD	(~PAGE_MASK)
diff --git a/arch/powerpc/include/asm/nohash/32/pte-8xx.h b/arch/powerpc/include/asm/nohash/32/pte-8xx.h
index 137dc3c84e45..625c31d6ce5c 100644
--- a/arch/powerpc/include/asm/nohash/32/pte-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/pte-8xx.h
@@ -74,12 +74,11 @@
 #define _PTE_NONE_MASK	0
 
 #ifdef CONFIG_PPC_16K_PAGES
-#define _PAGE_PSIZE	_PAGE_SPS
+#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_SPS)
 #else
-#define _PAGE_PSIZE		0
+#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED)
 #endif
 
-#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_PSIZE)
 #define _PAGE_BASE	(_PAGE_BASE_NC)
 
 #include <asm/pgtable-masks.h>
diff --git a/arch/powerpc/include/asm/nohash/pte-e500.h b/arch/powerpc/include/asm/nohash/pte-e500.h
index f516f0b5b7a8..975facc7e38e 100644
--- a/arch/powerpc/include/asm/nohash/pte-e500.h
+++ b/arch/powerpc/include/asm/nohash/pte-e500.h
@@ -65,8 +65,6 @@
 
 #define _PAGE_SPECIAL	_PAGE_SW0
 
-/* Base page size */
-#define _PAGE_PSIZE	_PAGE_PSIZE_4K
 #define	PTE_RPN_SHIFT	(24)
 
 #define PTE_WIMGE_SHIFT (19)
@@ -89,7 +87,7 @@
  * pages. We always set _PAGE_COHERENT when SMP is enabled or
  * the processor might need it for DMA coherency.
  */
-#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_PSIZE)
+#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_PSIZE_4K)
 #if defined(CONFIG_SMP)
 #define _PAGE_BASE	(_PAGE_BASE_NC | _PAGE_COHERENT)
 #else
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 10/23] powerpc/mm: Fix __find_linux_pte() on 32 bits with PMD leaf entries
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (8 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 09/23] powerpc/mm: Remove _PAGE_PSIZE Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 11/23] powerpc/mm: Allow hugepages without hugepd Christophe Leroy
                   ` (12 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

Building on 32 bits with pmd_leaf() not returning always false leads
to the following error:

  CC      arch/powerpc/mm/pgtable.o
arch/powerpc/mm/pgtable.c: In function '__find_linux_pte':
arch/powerpc/mm/pgtable.c:506:1: error: function may return address of local variable [-Werror=return-local-addr]
  506 | }
      | ^
arch/powerpc/mm/pgtable.c:394:15: note: declared here
  394 |         pud_t pud, *pudp;
      |               ^~~
arch/powerpc/mm/pgtable.c:394:15: note: declared here

This is due to pmd_offset() being a no-op in that case.

So rework it for powerpc/32 so that pXd_offset() are used on real
pointers and not on on-stack copies.

Behind fixing the problem, it also has the advantage of simplifying
__find_linux_pte() including the removal of stack frame:

After this patch:

	00000018 <__find_linux_pte>:
	  18:	2c 06 00 00 	cmpwi   r6,0
	  1c:	41 82 00 0c 	beq     28 <__find_linux_pte+0x10>
	  20:	39 20 00 00 	li      r9,0
	  24:	91 26 00 00 	stw     r9,0(r6)
	  28:	2f 85 00 00 	cmpwi   cr7,r5,0
	  2c:	41 9e 00 0c 	beq     cr7,38 <__find_linux_pte+0x20>
	  30:	39 20 00 00 	li      r9,0
	  34:	99 25 00 00 	stb     r9,0(r5)
	  38:	54 89 65 3a 	rlwinm  r9,r4,12,20,29
	  3c:	7c 63 48 2e 	lwzx    r3,r3,r9
	  40:	2f 83 00 00 	cmpwi   cr7,r3,0
	  44:	41 9e 00 30 	beq     cr7,74 <__find_linux_pte+0x5c>
	  48:	54 69 07 3a 	rlwinm  r9,r3,0,28,29
	  4c:	2f 89 00 0c 	cmpwi   cr7,r9,12
	  50:	54 63 00 26 	clrrwi  r3,r3,12
	  54:	54 84 b5 36 	rlwinm  r4,r4,22,20,27
	  58:	3c 63 c0 00 	addis   r3,r3,-16384
	  5c:	7c 63 22 14 	add     r3,r3,r4
	  60:	4c be 00 20 	bnelr+  cr7
	  64:	4d 82 00 20 	beqlr
	  68:	39 20 00 17 	li      r9,23
	  6c:	91 26 00 00 	stw     r9,0(r6)
	  70:	4e 80 00 20 	blr
	  74:	38 60 00 00 	li      r3,0
	  78:	4e 80 00 20 	blr

Before this patch:

	00000018 <__find_linux_pte>:
	  18:	2c 06 00 00 	cmpwi   r6,0
	  1c:	94 21 ff e0 	stwu    r1,-32(r1)
	  20:	41 82 00 0c 	beq     2c <__find_linux_pte+0x14>
	  24:	39 20 00 00 	li      r9,0
	  28:	91 26 00 00 	stw     r9,0(r6)
	  2c:	2f 85 00 00 	cmpwi   cr7,r5,0
	  30:	41 9e 00 0c 	beq     cr7,3c <__find_linux_pte+0x24>
	  34:	39 20 00 00 	li      r9,0
	  38:	99 25 00 00 	stb     r9,0(r5)
	  3c:	54 89 65 3a 	rlwinm  r9,r4,12,20,29
	  40:	7c 63 48 2e 	lwzx    r3,r3,r9
	  44:	54 69 07 3a 	rlwinm  r9,r3,0,28,29
	  48:	2f 89 00 0c 	cmpwi   cr7,r9,12
	  4c:	90 61 00 0c 	stw     r3,12(r1)
	  50:	41 9e 00 4c 	beq     cr7,9c <__find_linux_pte+0x84>
	  54:	80 61 00 0c 	lwz     r3,12(r1)
	  58:	54 69 07 3a 	rlwinm  r9,r3,0,28,29
	  5c:	2f 89 00 0c 	cmpwi   cr7,r9,12
	  60:	90 61 00 08 	stw     r3,8(r1)
	  64:	41 9e 00 38 	beq     cr7,9c <__find_linux_pte+0x84>
	  68:	80 61 00 08 	lwz     r3,8(r1)
	  6c:	2f 83 00 00 	cmpwi   cr7,r3,0
	  70:	41 9e 00 54 	beq     cr7,c4 <__find_linux_pte+0xac>
	  74:	54 69 07 3a 	rlwinm  r9,r3,0,28,29
	  78:	2f 89 00 0c 	cmpwi   cr7,r9,12
	  7c:	54 69 00 26 	clrrwi  r9,r3,12
	  80:	54 8a b5 36 	rlwinm  r10,r4,22,20,27
	  84:	3c 69 c0 00 	addis   r3,r9,-16384
	  88:	7c 63 52 14 	add     r3,r3,r10
	  8c:	54 84 93 be 	srwi    r4,r4,14
	  90:	41 9e 00 14 	beq     cr7,a4 <__find_linux_pte+0x8c>
	  94:	38 21 00 20 	addi    r1,r1,32
	  98:	4e 80 00 20 	blr
	  9c:	54 69 00 26 	clrrwi  r9,r3,12
	  a0:	54 84 93 be 	srwi    r4,r4,14
	  a4:	3c 69 c0 00 	addis   r3,r9,-16384
	  a8:	54 84 25 36 	rlwinm  r4,r4,4,20,27
	  ac:	7c 63 22 14 	add     r3,r3,r4
	  b0:	41 a2 ff e4 	beq     94 <__find_linux_pte+0x7c>
	  b4:	39 20 00 17 	li      r9,23
	  b8:	91 26 00 00 	stw     r9,0(r6)
	  bc:	38 21 00 20 	addi    r1,r1,32
	  c0:	4e 80 00 20 	blr
	  c4:	38 60 00 00 	li      r3,0
	  c8:	38 21 00 20 	addi    r1,r1,32
	  cc:	4e 80 00 20 	blr

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
---
v3: Removed p4dp and pudp locals for PPC32 and add a comment.
v4: Properly set pdshift on PPC32 case
v5: Enhanced commit message
---
 arch/powerpc/mm/pgtable.c | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 9e7ba9c3851f..bce8a8619589 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -382,8 +382,10 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
 			bool *is_thp, unsigned *hpage_shift)
 {
 	pgd_t *pgdp;
+#ifdef CONFIG_PPC64
 	p4d_t p4d, *p4dp;
 	pud_t pud, *pudp;
+#endif
 	pmd_t pmd, *pmdp;
 	pte_t *ret_pte;
 	hugepd_t *hpdp = NULL;
@@ -401,8 +403,12 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
 	 * page fault or a page unmap. The return pte_t * is still not
 	 * stable. So should be checked there for above conditions.
 	 * Top level is an exception because it is folded into p4d.
+	 *
+	 * On PPC32, P4D/PUD/PMD are folded into PGD so go straight to
+	 * PMD level.
 	 */
 	pgdp = pgdir + pgd_index(ea);
+#ifdef CONFIG_PPC64
 	p4dp = p4d_offset(pgdp, ea);
 	p4d  = READ_ONCE(*p4dp);
 	pdshift = P4D_SHIFT;
@@ -442,8 +448,11 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
 		goto out_huge;
 	}
 
-	pdshift = PMD_SHIFT;
 	pmdp = pmd_offset(&pud, ea);
+#else
+	pmdp = pmd_offset(pud_offset(p4d_offset(pgdp, ea), ea), ea);
+#endif
+	pdshift = PMD_SHIFT;
 	pmd  = READ_ONCE(*pmdp);
 
 	/*
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 11/23] powerpc/mm: Allow hugepages without hugepd
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (9 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 10/23] powerpc/mm: Fix __find_linux_pte() on 32 bits with PMD leaf entries Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 12/23] powerpc/8xx: Fix size given to set_huge_pte_at() Christophe Leroy
                   ` (11 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

In preparation of implementing huge pages on powerpc 8xx
without hugepd, enclose hugepd related code inside an
ifdef CONFIG_ARCH_HAS_HUGEPD

This also allows removing some stubs.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
---
v3:
- Prepare huge_pte_alloc() for full standard topology, not only for 2-level
- Reordered last part of huge_pte_alloc()

v4:
- Rebased of v6.10-rc1

v5:
- Moved the Kconfig split in this patch.
---
 arch/powerpc/Kconfig                         |  1 -
 arch/powerpc/include/asm/book3s/32/pgalloc.h |  2 --
 arch/powerpc/include/asm/hugetlb.h           | 10 ++----
 arch/powerpc/include/asm/nohash/pgtable.h    |  2 +-
 arch/powerpc/mm/hugetlbpage.c                | 33 ++++++++++++++++++++
 arch/powerpc/mm/pgtable.c                    |  2 ++
 arch/powerpc/platforms/Kconfig.cputype       |  3 ++
 7 files changed, 41 insertions(+), 12 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index c88c6d46a5bc..b60b6e991227 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -135,7 +135,6 @@ config PPC
 	select ARCH_HAS_DMA_MAP_DIRECT 		if PPC_PSERIES
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_GCOV_PROFILE_ALL
-	select ARCH_HAS_HUGEPD			if HUGETLB_PAGE
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_KERNEL_FPU_SUPPORT	if PPC64 && PPC_FPU
 	select ARCH_HAS_MEMBARRIER_CALLBACKS
diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h b/arch/powerpc/include/asm/book3s/32/pgalloc.h
index dc5c039eb28e..dd4eb3063175 100644
--- a/arch/powerpc/include/asm/book3s/32/pgalloc.h
+++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h
@@ -47,8 +47,6 @@ static inline void pgtable_free(void *table, unsigned index_size)
 	}
 }
 
-#define get_hugepd_cache_index(x)  (x)
-
 static inline void pgtable_free_tlb(struct mmu_gather *tlb,
 				    void *table, int shift)
 {
diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index ea71f7245a63..79176a499763 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -30,10 +30,12 @@ static inline int is_hugepage_only_range(struct mm_struct *mm,
 }
 #define is_hugepage_only_range is_hugepage_only_range
 
+#ifdef CONFIG_ARCH_HAS_HUGEPD
 #define __HAVE_ARCH_HUGETLB_FREE_PGD_RANGE
 void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
 			    unsigned long end, unsigned long floor,
 			    unsigned long ceiling);
+#endif
 
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
@@ -67,14 +69,6 @@ static inline void flush_hugetlb_page(struct vm_area_struct *vma,
 {
 }
 
-#define hugepd_shift(x) 0
-static inline pte_t *hugepte_offset(hugepd_t hpd, unsigned long addr,
-				    unsigned pdshift)
-{
-	return NULL;
-}
-
-
 static inline void __init gigantic_hugetlb_cma_reserve(void)
 {
 }
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index f5f39d4f03c8..e7fc1314c23e 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -340,7 +340,7 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
 
 #define pgprot_writecombine pgprot_noncached_wc
 
-#ifdef CONFIG_HUGETLB_PAGE
+#ifdef CONFIG_ARCH_HAS_HUGEPD
 static inline int hugepd_ok(hugepd_t hpd)
 {
 #ifdef CONFIG_PPC_8xx
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 594a4b7b2ca2..20fad59ff9f5 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -42,6 +42,7 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr, unsigned long s
 	return __find_linux_pte(mm->pgd, addr, NULL, NULL);
 }
 
+#ifdef CONFIG_ARCH_HAS_HUGEPD
 static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
 			   unsigned long address, unsigned int pdshift,
 			   unsigned int pshift, spinlock_t *ptl)
@@ -193,6 +194,36 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
 
 	return hugepte_offset(*hpdp, addr, pdshift);
 }
+#else
+pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
+		      unsigned long addr, unsigned long sz)
+{
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+
+	addr &= ~(sz - 1);
+
+	p4d = p4d_offset(pgd_offset(mm, addr), addr);
+	if (!mm_pud_folded(mm) && sz >= P4D_SIZE)
+		return (pte_t *)p4d;
+
+	pud = pud_alloc(mm, p4d, addr);
+	if (!pud)
+		return NULL;
+	if (!mm_pmd_folded(mm) && sz >= PUD_SIZE)
+		return (pte_t *)pud;
+
+	pmd = pmd_alloc(mm, pud, addr);
+	if (!pmd)
+		return NULL;
+
+	if (sz >= PMD_SIZE)
+		return (pte_t *)pmd;
+
+	return pte_alloc_huge(mm, pmd, addr);
+}
+#endif
 
 #ifdef CONFIG_PPC_BOOK3S_64
 /*
@@ -248,6 +279,7 @@ int __init alloc_bootmem_huge_page(struct hstate *h, int nid)
 	return __alloc_bootmem_huge_page(h, nid);
 }
 
+#ifdef CONFIG_ARCH_HAS_HUGEPD
 #ifndef CONFIG_PPC_BOOK3S_64
 #define HUGEPD_FREELIST_SIZE \
 	((PAGE_SIZE - sizeof(struct hugepd_freelist)) / sizeof(pte_t))
@@ -505,6 +537,7 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb,
 		}
 	} while (addr = next, addr != end);
 }
+#endif
 
 bool __init arch_hugetlb_valid_size(unsigned long size)
 {
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index bce8a8619589..9010973f036c 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -496,8 +496,10 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
 	if (!hpdp)
 		return NULL;
 
+#ifdef CONFIG_ARCH_HAS_HUGEPD
 	ret_pte = hugepte_offset(*hpdp, ea, pdshift);
 	pdshift = hugepd_shift(*hpdp);
+#endif
 out:
 	if (hpage_shift)
 		*hpage_shift = pdshift;
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index b2d8c0da2ad9..0c3c69ebf19f 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -37,6 +37,7 @@ config PPC_85xx
 
 config PPC_8xx
 	bool "Freescale 8xx"
+	select ARCH_HAS_HUGEPD if HUGETLB_PAGE
 	select ARCH_SUPPORTS_HUGETLBFS
 	select FSL_SOC
 	select PPC_KUEP
@@ -98,6 +99,7 @@ config PPC_BOOK3S_64
 	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
 	select ARCH_ENABLE_SPLIT_PMD_PTLOCK
 	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
+	select ARCH_HAS_HUGEPD if HUGETLB_PAGE
 	select ARCH_SUPPORTS_HUGETLBFS
 	select ARCH_SUPPORTS_NUMA_BALANCING
 	select HAVE_MOVE_PMD
@@ -290,6 +292,7 @@ config PPC_BOOK3S
 config PPC_E500
 	select FSL_EMB_PERFMON
 	bool
+	select ARCH_HAS_HUGEPD if HUGETLB_PAGE
 	select ARCH_SUPPORTS_HUGETLBFS if PHYS_64BIT || PPC64
 	select PPC_SMP_MUXED_IPI
 	select PPC_DOORBELL
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 12/23] powerpc/8xx: Fix size given to set_huge_pte_at()
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (10 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 11/23] powerpc/mm: Allow hugepages without hugepd Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 13/23] powerpc/8xx: Rework support for 8M pages using contiguous PTE entries Christophe Leroy
                   ` (10 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

set_huge_pte_at() expects the size of the hugepage as an int, not the
psize which is the index of the page definition in table mmu_psize_defs[]

Fixes: 935d4f0c6dc8 ("mm: hugetlb: add huge page size param to set_huge_pte_at()")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
---
 arch/powerpc/mm/nohash/8xx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index 43d4842bb1c7..d93433e26ded 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -94,7 +94,8 @@ static int __ref __early_map_kernel_hugepage(unsigned long va, phys_addr_t pa,
 		return -EINVAL;
 
 	set_huge_pte_at(&init_mm, va, ptep,
-			pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot)), psize);
+			pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot)),
+			1UL << mmu_psize_to_shift(psize));
 
 	return 0;
 }
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 13/23] powerpc/8xx: Rework support for 8M pages using contiguous PTE entries
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (11 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 12/23] powerpc/8xx: Fix size given to set_huge_pte_at() Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 14/23] powerpc/8xx: Simplify struct mmu_psize_def Christophe Leroy
                   ` (9 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

In order to fit better with standard Linux page tables layout, add
support for 8M pages using contiguous PTE entries in a standard
page table. Page tables will then be populated with 1024 similar
entries and two PMD entries will point to that page table.

The PMD entries also get a flag to tell it is addressing an 8M page,
this is required for the HW tablewalk assistance.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
---
v3:
- Move huge_ptep_get() for a more readable commit diff
- Flag PMD as 8Mbytes in set_huge_pte_at()
- Define __pte_leaf_size()
- Change pte_update() instead of all huge callers of pte_update()
- Added ptep_is_8m_pmdp() helper
- Fixed kasan early memory 8M allocation

v5:
- In huge_ptep_get(), change pte_offset_kernel((pmd_t *)ptep, 0) to pte_offset_kernel((pmd_t *)ptep, ALIGN_DOWN(addr, SZ_8M)) which is more correct allthough not different.
---
 .../include/asm/nohash/32/hugetlb-8xx.h       | 38 +++----------
 arch/powerpc/include/asm/nohash/32/pte-8xx.h  | 53 ++++++++++++-------
 arch/powerpc/include/asm/nohash/pgtable.h     |  4 --
 arch/powerpc/include/asm/page.h               |  5 --
 arch/powerpc/include/asm/pgtable.h            |  3 ++
 arch/powerpc/kernel/head_8xx.S                | 10 +---
 arch/powerpc/mm/hugetlbpage.c                 | 21 +++++---
 arch/powerpc/mm/kasan/8xx.c                   | 21 +++++---
 arch/powerpc/mm/nohash/8xx.c                  | 40 +++++++-------
 arch/powerpc/mm/pgtable.c                     | 27 +++++++---
 arch/powerpc/mm/pgtable_32.c                  |  2 +-
 arch/powerpc/platforms/Kconfig.cputype        |  1 -
 12 files changed, 111 insertions(+), 114 deletions(-)

diff --git a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
index 92df40c6cc6b..014799557f60 100644
--- a/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/hugetlb-8xx.h
@@ -4,42 +4,12 @@
 
 #define PAGE_SHIFT_8M		23
 
-static inline pte_t *hugepd_page(hugepd_t hpd)
-{
-	BUG_ON(!hugepd_ok(hpd));
-
-	return (pte_t *)__va(hpd_val(hpd) & ~HUGEPD_SHIFT_MASK);
-}
-
-static inline unsigned int hugepd_shift(hugepd_t hpd)
-{
-	return PAGE_SHIFT_8M;
-}
-
-static inline pte_t *hugepte_offset(hugepd_t hpd, unsigned long addr,
-				    unsigned int pdshift)
-{
-	unsigned long idx = (addr & (SZ_4M - 1)) >> PAGE_SHIFT;
-
-	return hugepd_page(hpd) + idx;
-}
-
 static inline void flush_hugetlb_page(struct vm_area_struct *vma,
 				      unsigned long vmaddr)
 {
 	flush_tlb_page(vma, vmaddr);
 }
 
-static inline void hugepd_populate(hugepd_t *hpdp, pte_t *new, unsigned int pshift)
-{
-	*hpdp = __hugepd(__pa(new) | _PMD_USER | _PMD_PRESENT | _PMD_PAGE_8M);
-}
-
-static inline void hugepd_populate_kernel(hugepd_t *hpdp, pte_t *new, unsigned int pshift)
-{
-	*hpdp = __hugepd(__pa(new) | _PMD_PRESENT | _PMD_PAGE_8M);
-}
-
 static inline int check_and_get_huge_psize(int shift)
 {
 	return shift_to_mmu_psize(shift);
@@ -49,6 +19,14 @@ static inline int check_and_get_huge_psize(int shift)
 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 		     pte_t pte, unsigned long sz);
 
+#define __HAVE_ARCH_HUGE_PTEP_GET
+static inline pte_t huge_ptep_get(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+	if (ptep_is_8m_pmdp(mm, addr, ptep))
+		ptep = pte_offset_kernel((pmd_t *)ptep, ALIGN_DOWN(addr, SZ_8M));
+	return ptep_get(ptep);
+}
+
 #define __HAVE_ARCH_HUGE_PTE_CLEAR
 static inline void huge_pte_clear(struct mm_struct *mm, unsigned long addr,
 				  pte_t *ptep, unsigned long sz)
diff --git a/arch/powerpc/include/asm/nohash/32/pte-8xx.h b/arch/powerpc/include/asm/nohash/32/pte-8xx.h
index 625c31d6ce5c..54ebb91dbdcf 100644
--- a/arch/powerpc/include/asm/nohash/32/pte-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/pte-8xx.h
@@ -119,7 +119,7 @@ static inline pte_t pte_mkhuge(pte_t pte)
 
 #define pte_mkhuge pte_mkhuge
 
-static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p,
+static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 				     unsigned long clr, unsigned long set, int huge);
 
 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
@@ -141,19 +141,12 @@ static inline void __ptep_set_access_flags(struct vm_area_struct *vma, pte_t *pt
 }
 #define __ptep_set_access_flags __ptep_set_access_flags
 
-static inline unsigned long pgd_leaf_size(pgd_t pgd)
-{
-	if (pgd_val(pgd) & _PMD_PAGE_8M)
-		return SZ_8M;
-	return SZ_4M;
-}
-
-#define pgd_leaf_size pgd_leaf_size
-
-static inline unsigned long pte_leaf_size(pte_t pte)
+static inline unsigned long __pte_leaf_size(pmd_t pmd, pte_t pte)
 {
 	pte_basic_t val = pte_val(pte);
 
+	if (pmd_val(pmd) & _PMD_PAGE_8M)
+		return SZ_8M;
 	if (val & _PAGE_HUGE)
 		return SZ_512K;
 	if (val & _PAGE_SPS)
@@ -161,31 +154,38 @@ static inline unsigned long pte_leaf_size(pte_t pte)
 	return SZ_4K;
 }
 
-#define pte_leaf_size pte_leaf_size
+#define __pte_leaf_size __pte_leaf_size
 
 /*
  * On the 8xx, the page tables are a bit special. For 16k pages, we have
  * 4 identical entries. For 512k pages, we have 128 entries as if it was
  * 4k pages, but they are flagged as 512k pages for the hardware.
- * For other page sizes, we have a single entry in the table.
+ * For 8M pages, we have 1024 entries as if it was 4M pages (PMD_SIZE)
+ * but they are flagged as 8M pages for the hardware.
+ * For 4k pages, we have a single entry in the table.
  */
 static pmd_t *pmd_off(struct mm_struct *mm, unsigned long addr);
-static int hugepd_ok(hugepd_t hpd);
+static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long address);
+
+static inline bool ptep_is_8m_pmdp(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+	return (pmd_t *)ptep == pmd_off(mm, ALIGN_DOWN(addr, SZ_8M));
+}
 
 static inline int number_of_cells_per_pte(pmd_t *pmd, pte_basic_t val, int huge)
 {
 	if (!huge)
 		return PAGE_SIZE / SZ_4K;
-	else if (hugepd_ok(*((hugepd_t *)pmd)))
-		return 1;
+	else if ((pmd_val(*pmd) & _PMD_PAGE_MASK) == _PMD_PAGE_8M)
+		return SZ_4M / SZ_4K;
 	else if (IS_ENABLED(CONFIG_PPC_4K_PAGES) && !(val & _PAGE_HUGE))
 		return SZ_16K / SZ_4K;
 	else
 		return SZ_512K / SZ_4K;
 }
 
-static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p,
-				     unsigned long clr, unsigned long set, int huge)
+static inline pte_basic_t __pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p,
+				       unsigned long clr, unsigned long set, int huge)
 {
 	pte_basic_t *entry = (pte_basic_t *)p;
 	pte_basic_t old = pte_val(*p);
@@ -197,7 +197,7 @@ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, p
 
 	for (i = 0; i < num; i += PAGE_SIZE / SZ_4K, new += PAGE_SIZE) {
 		*entry++ = new;
-		if (IS_ENABLED(CONFIG_PPC_16K_PAGES) && num != 1) {
+		if (IS_ENABLED(CONFIG_PPC_16K_PAGES)) {
 			*entry++ = new;
 			*entry++ = new;
 			*entry++ = new;
@@ -207,6 +207,21 @@ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, p
 	return old;
 }
 
+static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+				     unsigned long clr, unsigned long set, int huge)
+{
+	pte_basic_t old;
+
+	if (huge && ptep_is_8m_pmdp(mm, addr, ptep)) {
+		pmd_t *pmdp = (pmd_t *)ptep;
+
+		old = __pte_update(mm, addr, pte_offset_kernel(pmdp, 0), clr, set, huge);
+		__pte_update(mm, addr, pte_offset_kernel(pmdp + 1, 0), clr, set, huge);
+	} else {
+		old = __pte_update(mm, addr, ptep, clr, set, huge);
+	}
+	return old;
+}
 #define pte_update pte_update
 
 #ifdef CONFIG_PPC_16K_PAGES
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index e7fc1314c23e..90d6a0943b35 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -343,12 +343,8 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
 #ifdef CONFIG_ARCH_HAS_HUGEPD
 static inline int hugepd_ok(hugepd_t hpd)
 {
-#ifdef CONFIG_PPC_8xx
-	return ((hpd_val(hpd) & _PMD_PAGE_MASK) == _PMD_PAGE_8M);
-#else
 	/* We clear the top bit to indicate hugepd */
 	return (hpd_val(hpd) && (hpd_val(hpd) & PD_HUGE) == 0);
-#endif
 }
 
 #define is_hugepd(hpd)		(hugepd_ok(hpd))
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index e411e5a70ea3..018c3d55232c 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -293,13 +293,8 @@ static inline const void *pfn_to_kaddr(unsigned long pfn)
 /*
  * Some number of bits at the level of the page table that points to
  * a hugepte are used to encode the size.  This masks those bits.
- * On 8xx, HW assistance requires 4k alignment for the hugepte.
  */
-#ifdef CONFIG_PPC_8xx
-#define HUGEPD_SHIFT_MASK     0xfff
-#else
 #define HUGEPD_SHIFT_MASK     0x3f
-#endif
 
 #ifndef __ASSEMBLY__
 
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index 239709a2f68e..264a6c09517a 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -106,6 +106,9 @@ unsigned long vmalloc_to_phys(void *vmalloc_addr);
 
 void pgtable_cache_add(unsigned int shift);
 
+#ifdef CONFIG_PPC32
+void __init *early_alloc_pgtable(unsigned long size);
+#endif
 pte_t *early_pte_alloc_kernel(pmd_t *pmdp, unsigned long va);
 
 #if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_PPC32)
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index edc479a7c2bc..ac74321b1192 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -415,14 +415,13 @@ FixupDAR:/* Entry point for dcbx workaround. */
 	oris	r11, r11, (swapper_pg_dir - PAGE_OFFSET)@ha
 3:
 	lwz	r11, (swapper_pg_dir-PAGE_OFFSET)@l(r11)	/* Get the level 1 entry */
+	rlwinm	r11, r11, 0, ~_PMD_PAGE_8M
 	mtspr	SPRN_MD_TWC, r11
-	mtcrf	0x01, r11
 	mfspr	r11, SPRN_MD_TWC
 	lwz	r11, 0(r11)	/* Get the pte */
-	bt	28,200f		/* bit 28 = Large page (8M) */
 	/* concat physical page address(r11) and page offset(r10) */
 	rlwimi	r11, r10, 0, 32 - PAGE_SHIFT, 31
-201:	lwz	r11,0(r11)
+	lwz	r11,0(r11)
 /* Check if it really is a dcbx instruction. */
 /* dcbt and dcbtst does not generate DTLB Misses/Errors,
  * no need to include them here */
@@ -441,11 +440,6 @@ FixupDAR:/* Entry point for dcbx workaround. */
 141:	mfspr	r10,SPRN_M_TW
 	b	DARFixed	/* Nope, go back to normal TLB processing */
 
-200:
-	/* concat physical page address(r11) and page offset(r10) */
-	rlwimi	r11, r10, 0, 32 - PAGE_SHIFT_8M, 31
-	b	201b
-
 144:	mfspr	r10, SPRN_DSISR
 	rlwinm	r10, r10,0,7,5	/* Clear store bit for buggy dcbst insn */
 	mtspr	SPRN_DSISR, r10
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 20fad59ff9f5..394846197974 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -183,9 +183,6 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
 	if (!hpdp)
 		return NULL;
 
-	if (IS_ENABLED(CONFIG_PPC_8xx) && pshift < PMD_SHIFT)
-		return pte_alloc_huge(mm, (pmd_t *)hpdp, addr);
-
 	BUG_ON(!hugepd_none(*hpdp) && !hugepd_ok(*hpdp));
 
 	if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr,
@@ -218,8 +215,18 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
 	if (!pmd)
 		return NULL;
 
-	if (sz >= PMD_SIZE)
+	if (sz >= PMD_SIZE) {
+		/* On 8xx, all hugepages are handled as contiguous PTEs */
+		if (IS_ENABLED(CONFIG_PPC_8xx)) {
+			int i;
+
+			for (i = 0; i < sz / PMD_SIZE; i++) {
+				if (!pte_alloc_huge(mm, pmd + i, addr))
+					return NULL;
+			}
+		}
 		return (pte_t *)pmd;
+	}
 
 	return pte_alloc_huge(mm, pmd, addr);
 }
@@ -617,10 +624,8 @@ static int __init hugetlbpage_init(void)
 		 * use pgt cache for hugepd.
 		 */
 		if (pdshift > shift) {
-			if (!IS_ENABLED(CONFIG_PPC_8xx))
-				pgtable_cache_add(pdshift - shift);
-		} else if (IS_ENABLED(CONFIG_PPC_E500) ||
-			   IS_ENABLED(CONFIG_PPC_8xx)) {
+			pgtable_cache_add(pdshift - shift);
+		} else if (IS_ENABLED(CONFIG_PPC_E500)) {
 			pgtable_cache_add(PTE_T_ORDER);
 		}
 
diff --git a/arch/powerpc/mm/kasan/8xx.c b/arch/powerpc/mm/kasan/8xx.c
index 2784224054f8..989d6cdf4141 100644
--- a/arch/powerpc/mm/kasan/8xx.c
+++ b/arch/powerpc/mm/kasan/8xx.c
@@ -6,28 +6,33 @@
 #include <linux/memblock.h>
 #include <linux/hugetlb.h>
 
+#include <asm/pgalloc.h>
+
 static int __init
 kasan_init_shadow_8M(unsigned long k_start, unsigned long k_end, void *block)
 {
 	pmd_t *pmd = pmd_off_k(k_start);
 	unsigned long k_cur, k_next;
 
-	for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd += 2, block += SZ_8M) {
-		pte_basic_t *new;
+	for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++, block += SZ_4M) {
+		pte_t *ptep;
+		int i;
 
 		k_next = pgd_addr_end(k_cur, k_end);
-		k_next = pgd_addr_end(k_next, k_end);
 		if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
 			continue;
 
-		new = memblock_alloc(sizeof(pte_basic_t), SZ_4K);
-		if (!new)
+		ptep = memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE);
+		if (!ptep)
 			return -ENOMEM;
 
-		*new = pte_val(pte_mkhuge(pfn_pte(PHYS_PFN(__pa(block)), PAGE_KERNEL)));
+		for (i = 0; i < PTRS_PER_PTE; i++) {
+			pte_t pte = pte_mkhuge(pfn_pte(PHYS_PFN(__pa(block + i * PAGE_SIZE)), PAGE_KERNEL));
 
-		hugepd_populate_kernel((hugepd_t *)pmd, (pte_t *)new, PAGE_SHIFT_8M);
-		hugepd_populate_kernel((hugepd_t *)pmd + 1, (pte_t *)new, PAGE_SHIFT_8M);
+			__set_pte_at(&init_mm, k_cur, ptep + i, pte, 1);
+		}
+		pmd_populate_kernel(&init_mm, pmd, ptep);
+		*pmd = __pmd(pmd_val(*pmd) | _PMD_PAGE_8M);
 	}
 	return 0;
 }
diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c
index d93433e26ded..388bba0ab3e7 100644
--- a/arch/powerpc/mm/nohash/8xx.c
+++ b/arch/powerpc/mm/nohash/8xx.c
@@ -11,6 +11,7 @@
 #include <linux/hugetlb.h>
 
 #include <asm/fixmap.h>
+#include <asm/pgalloc.h>
 
 #include <mm/mmu_decl.h>
 
@@ -48,20 +49,6 @@ unsigned long p_block_mapped(phys_addr_t pa)
 	return 0;
 }
 
-static pte_t __init *early_hugepd_alloc_kernel(hugepd_t *pmdp, unsigned long va)
-{
-	if (hpd_val(*pmdp) == 0) {
-		pte_t *ptep = memblock_alloc(sizeof(pte_basic_t), SZ_4K);
-
-		if (!ptep)
-			return NULL;
-
-		hugepd_populate_kernel((hugepd_t *)pmdp, ptep, PAGE_SHIFT_8M);
-		hugepd_populate_kernel((hugepd_t *)pmdp + 1, ptep, PAGE_SHIFT_8M);
-	}
-	return hugepte_offset(*(hugepd_t *)pmdp, va, PGDIR_SHIFT);
-}
-
 static int __ref __early_map_kernel_hugepage(unsigned long va, phys_addr_t pa,
 					     pgprot_t prot, int psize, bool new)
 {
@@ -75,24 +62,33 @@ static int __ref __early_map_kernel_hugepage(unsigned long va, phys_addr_t pa,
 		if (WARN_ON(slab_is_available()))
 			return -EINVAL;
 
-		if (psize == MMU_PAGE_512K)
+		if (psize == MMU_PAGE_512K) {
 			ptep = early_pte_alloc_kernel(pmdp, va);
-		else
-			ptep = early_hugepd_alloc_kernel((hugepd_t *)pmdp, va);
+			/* The PTE should never be already present */
+			if (WARN_ON(pte_present(*ptep) && pgprot_val(prot)))
+				return -EINVAL;
+		} else {
+			if (WARN_ON(!pmd_none(*pmdp) || !pmd_none(*(pmdp + 1))))
+				return -EINVAL;
+
+			ptep = early_alloc_pgtable(PTE_FRAG_SIZE);
+			pmd_populate_kernel(&init_mm, pmdp, ptep);
+
+			ptep = early_alloc_pgtable(PTE_FRAG_SIZE);
+			pmd_populate_kernel(&init_mm, pmdp + 1, ptep);
+
+			ptep = (pte_t *)pmdp;
+		}
 	} else {
 		if (psize == MMU_PAGE_512K)
 			ptep = pte_offset_kernel(pmdp, va);
 		else
-			ptep = hugepte_offset(*(hugepd_t *)pmdp, va, PGDIR_SHIFT);
+			ptep = (pte_t *)pmdp;
 	}
 
 	if (WARN_ON(!ptep))
 		return -ENOMEM;
 
-	/* The PTE should never be already present */
-	if (new && WARN_ON(pte_present(*ptep) && pgprot_val(prot)))
-		return -EINVAL;
-
 	set_huge_pte_at(&init_mm, va, ptep,
 			pte_mkhuge(pfn_pte(pa >> PAGE_SHIFT, prot)),
 			1UL << mmu_psize_to_shift(psize));
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 9010973f036c..294775c793ab 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -297,11 +297,8 @@ int huge_ptep_set_access_flags(struct vm_area_struct *vma,
 }
 
 #if defined(CONFIG_PPC_8xx)
-void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
-		     pte_t pte, unsigned long sz)
+static void __set_huge_pte_at(pmd_t *pmd, pte_t *ptep, pte_basic_t val)
 {
-	pmd_t *pmd = pmd_off(mm, addr);
-	pte_basic_t val;
 	pte_basic_t *entry = (pte_basic_t *)ptep;
 	int num, i;
 
@@ -311,15 +308,29 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 	 */
 	VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep));
 
-	pte = set_pte_filter(pte, addr);
-
-	val = pte_val(pte);
-
 	num = number_of_cells_per_pte(pmd, val, 1);
 
 	for (i = 0; i < num; i++, entry++, val += SZ_4K)
 		*entry = val;
 }
+
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+		     pte_t pte, unsigned long sz)
+{
+	pmd_t *pmdp = pmd_off(mm, addr);
+
+	pte = set_pte_filter(pte, addr);
+
+	if (sz == SZ_8M) { /* Flag both PMD entries as 8M and fill both page tables */
+		*pmdp = __pmd(pmd_val(*pmdp) | _PMD_PAGE_8M);
+		*(pmdp + 1) = __pmd(pmd_val(*(pmdp + 1)) | _PMD_PAGE_8M);
+
+		__set_huge_pte_at(pmdp, pte_offset_kernel(pmdp, 0), pte_val(pte));
+		__set_huge_pte_at(pmdp, pte_offset_kernel(pmdp + 1, 0), pte_val(pte) + SZ_4M);
+	} else {
+		__set_huge_pte_at(pmdp, ptep, pte_val(pte));
+	}
+}
 #endif
 #endif /* CONFIG_HUGETLB_PAGE */
 
diff --git a/arch/powerpc/mm/pgtable_32.c b/arch/powerpc/mm/pgtable_32.c
index cfd622ebf774..787b22206386 100644
--- a/arch/powerpc/mm/pgtable_32.c
+++ b/arch/powerpc/mm/pgtable_32.c
@@ -48,7 +48,7 @@ notrace void __init early_ioremap_init(void)
 	early_ioremap_setup();
 }
 
-static void __init *early_alloc_pgtable(unsigned long size)
+void __init *early_alloc_pgtable(unsigned long size)
 {
 	void *ptr = memblock_alloc(size, size);
 
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 0c3c69ebf19f..fa4bb096b3ae 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -37,7 +37,6 @@ config PPC_85xx
 
 config PPC_8xx
 	bool "Freescale 8xx"
-	select ARCH_HAS_HUGEPD if HUGETLB_PAGE
 	select ARCH_SUPPORTS_HUGETLBFS
 	select FSL_SOC
 	select PPC_KUEP
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 14/23] powerpc/8xx: Simplify struct mmu_psize_def
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (12 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 13/23] powerpc/8xx: Rework support for 8M pages using contiguous PTE entries Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 15/23] powerpc/e500: Remove enc and ind fields from " Christophe Leroy
                   ` (8 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

On 8xx, only the shift field is used in struct mmu_psize_def

Remove other fields and related macros.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
---
 arch/powerpc/include/asm/nohash/32/mmu-8xx.h | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/arch/powerpc/include/asm/nohash/32/mmu-8xx.h b/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
index 141d82e249a8..a756a1e59c54 100644
--- a/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
+++ b/arch/powerpc/include/asm/nohash/32/mmu-8xx.h
@@ -189,19 +189,14 @@ typedef struct {
 
 #define PHYS_IMMR_BASE (mfspr(SPRN_IMMR) & 0xfff80000)
 
-/* Page size definitions, common between 32 and 64-bit
+/*
+ * Page size definitions for 8xx
  *
  *    shift : is the "PAGE_SHIFT" value for that page size
- *    penc  : is the pte encoding mask
  *
  */
 struct mmu_psize_def {
 	unsigned int	shift;	/* number of bits */
-	unsigned int	enc;	/* PTE encoding */
-	unsigned int    ind;    /* Corresponding indirect page size shift */
-	unsigned int	flags;
-#define MMU_PAGE_SIZE_DIRECT	0x1	/* Supported as a direct size */
-#define MMU_PAGE_SIZE_INDIRECT	0x2	/* Supported as an indirect size */
 };
 
 extern struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 15/23] powerpc/e500: Remove enc and ind fields from struct mmu_psize_def
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (13 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 14/23] powerpc/8xx: Simplify struct mmu_psize_def Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 16/23] powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits) Christophe Leroy
                   ` (7 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

enc field is hidden behind BOOK3E_PAGESZ_XX macros, and when you look
closer you realise that this field is nothing else than the value of
shift minus ten.

So remove enc field and calculate tsize from shift field.

Also remove inc field which is unused.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
---
 arch/powerpc/include/asm/nohash/mmu-e500.h | 3 ---
 arch/powerpc/mm/nohash/book3e_pgtable.c    | 4 ++--
 arch/powerpc/mm/nohash/tlb.c               | 9 +--------
 arch/powerpc/mm/nohash/tlb_64e.c           | 2 +-
 4 files changed, 4 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/include/asm/nohash/mmu-e500.h b/arch/powerpc/include/asm/nohash/mmu-e500.h
index 7dc24b8632d7..b281d9eeaf1e 100644
--- a/arch/powerpc/include/asm/nohash/mmu-e500.h
+++ b/arch/powerpc/include/asm/nohash/mmu-e500.h
@@ -244,14 +244,11 @@ typedef struct {
 /* Page size definitions, common between 32 and 64-bit
  *
  *    shift : is the "PAGE_SHIFT" value for that page size
- *    penc  : is the pte encoding mask
  *
  */
 struct mmu_psize_def
 {
 	unsigned int	shift;	/* number of bits */
-	unsigned int	enc;	/* PTE encoding */
-	unsigned int    ind;    /* Corresponding indirect page size shift */
 	unsigned int	flags;
 #define MMU_PAGE_SIZE_DIRECT	0x1	/* Supported as a direct size */
 #define MMU_PAGE_SIZE_INDIRECT	0x2	/* Supported as an indirect size */
diff --git a/arch/powerpc/mm/nohash/book3e_pgtable.c b/arch/powerpc/mm/nohash/book3e_pgtable.c
index 1c5e4ecbebeb..ad2a7c26f2a0 100644
--- a/arch/powerpc/mm/nohash/book3e_pgtable.c
+++ b/arch/powerpc/mm/nohash/book3e_pgtable.c
@@ -29,10 +29,10 @@ int __meminit vmemmap_create_mapping(unsigned long start,
 		_PAGE_KERNEL_RW;
 
 	/* PTEs only contain page size encodings up to 32M */
-	BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].enc > 0xf);
+	BUG_ON(mmu_psize_defs[mmu_vmemmap_psize].shift - 10 > 0xf);
 
 	/* Encode the size in the PTE */
-	flags |= mmu_psize_defs[mmu_vmemmap_psize].enc << 8;
+	flags |= (mmu_psize_defs[mmu_vmemmap_psize].shift - 10) << 8;
 
 	/* For each PTE for that area, map things. Note that we don't
 	 * increment phys because all PTEs are of the large size and
diff --git a/arch/powerpc/mm/nohash/tlb.c b/arch/powerpc/mm/nohash/tlb.c
index f57dc721d063..b653a7be4cb1 100644
--- a/arch/powerpc/mm/nohash/tlb.c
+++ b/arch/powerpc/mm/nohash/tlb.c
@@ -53,37 +53,30 @@
 struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT] = {
 	[MMU_PAGE_4K] = {
 		.shift	= 12,
-		.enc	= BOOK3E_PAGESZ_4K,
 	},
 	[MMU_PAGE_2M] = {
 		.shift	= 21,
-		.enc	= BOOK3E_PAGESZ_2M,
 	},
 	[MMU_PAGE_4M] = {
 		.shift	= 22,
-		.enc	= BOOK3E_PAGESZ_4M,
 	},
 	[MMU_PAGE_16M] = {
 		.shift	= 24,
-		.enc	= BOOK3E_PAGESZ_16M,
 	},
 	[MMU_PAGE_64M] = {
 		.shift	= 26,
-		.enc	= BOOK3E_PAGESZ_64M,
 	},
 	[MMU_PAGE_256M] = {
 		.shift	= 28,
-		.enc	= BOOK3E_PAGESZ_256M,
 	},
 	[MMU_PAGE_1G] = {
 		.shift	= 30,
-		.enc	= BOOK3E_PAGESZ_1GB,
 	},
 };
 
 static inline int mmu_get_tsize(int psize)
 {
-	return mmu_psize_defs[psize].enc;
+	return mmu_psize_defs[psize].shift - 10;
 }
 #else
 static inline int mmu_get_tsize(int psize)
diff --git a/arch/powerpc/mm/nohash/tlb_64e.c b/arch/powerpc/mm/nohash/tlb_64e.c
index 053128a5636c..7988238496d7 100644
--- a/arch/powerpc/mm/nohash/tlb_64e.c
+++ b/arch/powerpc/mm/nohash/tlb_64e.c
@@ -53,7 +53,7 @@ int extlb_level_exc;
  */
 void tlb_flush_pgtable(struct mmu_gather *tlb, unsigned long address)
 {
-	int tsize = mmu_psize_defs[mmu_pte_psize].enc;
+	int tsize = mmu_psize_defs[mmu_pte_psize].shift - 10;
 
 	if (book3e_htw_mode != PPC_HTW_NONE) {
 		unsigned long start = address & PMD_MASK;
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 16/23] powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits)
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (14 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 15/23] powerpc/e500: Remove enc and ind fields from " Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-29 22:10   ` Guenter Roeck
  2024-07-02 13:51 ` [PATCH v7 17/23] powerpc/e500: Encode hugepage size in PTE bits Christophe Leroy
                   ` (6 subsequent siblings)
  22 siblings, 1 reply; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

At the time being when CONFIG_PTE_64BIT is selected, PTE entries are
64 bits but PGD entries are still 32 bits.

In order to allow leaf PMD entries, switch the PGD to 64 bits entries.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
 arch/powerpc/include/asm/pgtable-types.h |  4 ++++
 arch/powerpc/kernel/head_85xx.S          | 10 ++++++----
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/pgtable-types.h b/arch/powerpc/include/asm/pgtable-types.h
index 082c85cc09b1..db965d98e0ae 100644
--- a/arch/powerpc/include/asm/pgtable-types.h
+++ b/arch/powerpc/include/asm/pgtable-types.h
@@ -49,7 +49,11 @@ static inline unsigned long pud_val(pud_t x)
 #endif /* CONFIG_PPC64 */
 
 /* PGD level */
+#if defined(CONFIG_PPC_E500) && defined(CONFIG_PTE_64BIT)
+typedef struct { unsigned long long pgd; } pgd_t;
+#else
 typedef struct { unsigned long pgd; } pgd_t;
+#endif
 #define __pgd(x)	((pgd_t) { (x) })
 static inline unsigned long pgd_val(pgd_t x)
 {
diff --git a/arch/powerpc/kernel/head_85xx.S b/arch/powerpc/kernel/head_85xx.S
index 39724ff5ae1f..a305244afc9f 100644
--- a/arch/powerpc/kernel/head_85xx.S
+++ b/arch/powerpc/kernel/head_85xx.S
@@ -307,8 +307,9 @@ set_ivor:
 #ifdef CONFIG_PTE_64BIT
 #ifdef CONFIG_HUGETLB_PAGE
 #define FIND_PTE	\
-	rlwinm	r12, r10, 13, 19, 29;	/* Compute pgdir/pmd offset */	\
-	lwzx	r11, r12, r11;		/* Get pgd/pmd entry */		\
+	rlwinm	r12, r10, 14, 18, 28;	/* Compute pgdir/pmd offset */	\
+	add	r12, r11, r12;						\
+	lwz	r11, 4(r12);		/* Get pgd/pmd entry */		\
 	rlwinm.	r12, r11, 0, 0, 20;	/* Extract pt base address */	\
 	blt	1000f;			/* Normal non-huge page */	\
 	beq	2f;			/* Bail if no table */		\
@@ -321,8 +322,9 @@ set_ivor:
 1001:	lwz	r11, 4(r12);		/* Get pte entry */
 #else
 #define FIND_PTE	\
-	rlwinm	r12, r10, 13, 19, 29;	/* Compute pgdir/pmd offset */	\
-	lwzx	r11, r12, r11;		/* Get pgd/pmd entry */		\
+	rlwinm	r12, r10, 14, 18, 28;	/* Compute pgdir/pmd offset */	\
+	add	r12, r11, r12;						\
+	lwz	r11, 4(r12);		/* Get pgd/pmd entry */		\
 	rlwinm.	r12, r11, 0, 0, 20;	/* Extract pt base address */	\
 	beq	2f;			/* Bail if no table */		\
 	rlwimi	r12, r10, 23, 20, 28;	/* Compute pte address */	\
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 17/23] powerpc/e500: Encode hugepage size in PTE bits
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (15 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 16/23] powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits) Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 18/23] powerpc/e500: Don't pre-check write access on data TLB error Christophe Leroy
                   ` (5 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

Use PTE page size bits to encode hugepage size with the following
format corresponding to the values expected in bits 52-55 in MAS1
register. Those bits are called TSIZE:
	0001 	4 Kbyte
	0010 	16 Kbyte
	0011 	64 Kbyte
	0100 	256 Kbyte
	0101 	1 Mbyte
	0110 	4 Mbyte
	0111 	16 Mbyte
	1000 	64 Mbyte
	1001 	256 Mbyte
	1010 	1 Gbyte
	1011 	4 Gbyte
	1100 	16 Gbyte
	1101	64 Gbyte
	1110	256 Gbyte
	1111	1 Tbyte

It corresponds to shift value minus 10 with lowest bit removed.

It is not the value expected in the PTE in that field, but only
e6500 performs HW based TLB loading and the e6500 reference manual
explicitely says that this field is ignored.

Also add pte_huge_size() which will be used later.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v5: Use PAGE SIZE field instead of U0-U3 because on some HW U2-U3 are used for something else.
---
 .../powerpc/include/asm/nohash/hugetlb-e500.h |  9 ++++++
 arch/powerpc/include/asm/nohash/pte-e500.h    | 28 +++++++++----------
 2 files changed, 22 insertions(+), 15 deletions(-)

diff --git a/arch/powerpc/include/asm/nohash/hugetlb-e500.h b/arch/powerpc/include/asm/nohash/hugetlb-e500.h
index 8f04ad20e040..c6a0938e86fd 100644
--- a/arch/powerpc/include/asm/nohash/hugetlb-e500.h
+++ b/arch/powerpc/include/asm/nohash/hugetlb-e500.h
@@ -42,4 +42,13 @@ static inline int check_and_get_huge_psize(int shift)
 	return shift_to_mmu_psize(shift);
 }
 
+static inline pte_t arch_make_huge_pte(pte_t entry, unsigned int shift, vm_flags_t flags)
+{
+	unsigned int tsize = shift - _PAGE_PSIZE_SHIFT_OFFSET;
+	pte_basic_t val = (tsize << _PAGE_PSIZE_SHIFT) & _PAGE_PSIZE_MSK;
+
+	return __pte((pte_val(entry) & ~(pte_basic_t)_PAGE_PSIZE_MSK) | val);
+}
+#define arch_make_huge_pte arch_make_huge_pte
+
 #endif /* _ASM_POWERPC_NOHASH_HUGETLB_E500_H */
diff --git a/arch/powerpc/include/asm/nohash/pte-e500.h b/arch/powerpc/include/asm/nohash/pte-e500.h
index 975facc7e38e..6dac1c0a6937 100644
--- a/arch/powerpc/include/asm/nohash/pte-e500.h
+++ b/arch/powerpc/include/asm/nohash/pte-e500.h
@@ -19,20 +19,7 @@
 #define _PAGE_BAP_SX	0x000040
 #define _PAGE_BAP_UX	0x000080
 #define _PAGE_PSIZE_MSK	0x000f00
-#define _PAGE_PSIZE_4K	0x000200
-#define _PAGE_PSIZE_8K	0x000300
-#define _PAGE_PSIZE_16K	0x000400
-#define _PAGE_PSIZE_32K	0x000500
-#define _PAGE_PSIZE_64K	0x000600
-#define _PAGE_PSIZE_128K	0x000700
-#define _PAGE_PSIZE_256K	0x000800
-#define _PAGE_PSIZE_512K	0x000900
-#define _PAGE_PSIZE_1M	0x000a00
-#define _PAGE_PSIZE_2M	0x000b00
-#define _PAGE_PSIZE_4M	0x000c00
-#define _PAGE_PSIZE_8M	0x000d00
-#define _PAGE_PSIZE_16M	0x000e00
-#define _PAGE_PSIZE_32M	0x000f00
+#define _PAGE_TSIZE_4K	0x000100
 #define _PAGE_DIRTY	0x001000 /* C: page changed */
 #define _PAGE_SW0	0x002000
 #define _PAGE_U3	0x004000
@@ -46,6 +33,9 @@
 #define _PAGE_NO_CACHE	0x400000 /* I: cache inhibit */
 #define _PAGE_WRITETHRU	0x800000 /* W: cache write-through */
 
+#define _PAGE_PSIZE_SHIFT		7
+#define _PAGE_PSIZE_SHIFT_OFFSET	10
+
 /* "Higher level" linux bit combinations */
 #define _PAGE_EXEC		(_PAGE_BAP_SX | _PAGE_BAP_UX) /* .. and was cache cleaned */
 #define _PAGE_READ		(_PAGE_BAP_SR | _PAGE_BAP_UR) /* User read permission */
@@ -87,7 +77,7 @@
  * pages. We always set _PAGE_COHERENT when SMP is enabled or
  * the processor might need it for DMA coherency.
  */
-#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_PSIZE_4K)
+#define _PAGE_BASE_NC	(_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_TSIZE_4K)
 #if defined(CONFIG_SMP)
 #define _PAGE_BASE	(_PAGE_BASE_NC | _PAGE_COHERENT)
 #else
@@ -103,6 +93,14 @@ static inline pte_t pte_mkexec(pte_t pte)
 }
 #define pte_mkexec pte_mkexec
 
+static inline unsigned long pte_huge_size(pte_t pte)
+{
+	pte_basic_t val = pte_val(pte);
+
+	return 1UL << (((val & _PAGE_PSIZE_MSK) >> _PAGE_PSIZE_SHIFT) + _PAGE_PSIZE_SHIFT_OFFSET);
+}
+#define pte_huge_size pte_huge_size
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __KERNEL__ */
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 18/23] powerpc/e500: Don't pre-check write access on data TLB error
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (16 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 17/23] powerpc/e500: Encode hugepage size in PTE bits Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 19/23] powerpc/e500: Free r10 for FIND_PTE Christophe Leroy
                   ` (4 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

Don't pre-check write access on read-only pages on data TLB error.

Load the TLB anyway and take a DSI exception when it happens. This
avoids reading SPRN_ESR at every data TLB error exception.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v5: New
---
 arch/powerpc/kernel/head_85xx.S | 15 ---------------
 1 file changed, 15 deletions(-)

diff --git a/arch/powerpc/kernel/head_85xx.S b/arch/powerpc/kernel/head_85xx.S
index a305244afc9f..282e49c51deb 100644
--- a/arch/powerpc/kernel/head_85xx.S
+++ b/arch/powerpc/kernel/head_85xx.S
@@ -472,27 +472,12 @@ END_BTB_FLUSH_SECTION
 #endif
 
 4:
-	/* Mask of required permission bits. Note that while we
-	 * do copy ESR:ST to _PAGE_WRITE position as trying to write
-	 * to an RO page is pretty common, we don't do it with
-	 * _PAGE_DIRTY. We could do it, but it's a fairly rare
-	 * event so I'd rather take the overhead when it happens
-	 * rather than adding an instruction here. We should measure
-	 * whether the whole thing is worth it in the first place
-	 * as we could avoid loading SPRN_ESR completely in the first
-	 * place...
-	 *
-	 * TODO: Is it worth doing that mfspr & rlwimi in the first
-	 *       place or can we save a couple of instructions here ?
-	 */
-	mfspr	r12,SPRN_ESR
 #ifdef CONFIG_PTE_64BIT
 	li	r13,_PAGE_PRESENT|_PAGE_BAP_SR
 	oris	r13,r13,_PAGE_ACCESSED@h
 #else
 	li	r13,_PAGE_PRESENT|_PAGE_READ|_PAGE_ACCESSED
 #endif
-	rlwimi	r13,r12,11,29,29
 
 	FIND_PTE
 	andc.	r13,r13,r11		/* Check permission */
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 19/23] powerpc/e500: Free r10 for FIND_PTE
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (17 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 18/23] powerpc/e500: Don't pre-check write access on data TLB error Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 20/23] powerpc/e500: Use contiguous PMD instead of hugepd Christophe Leroy
                   ` (3 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

Move r13 load after the call to FIND_PTE, and use r13 instead of
r10 for storing fault address. This will allow using r10 freely
in FIND_PTE in following patch to handle hugepage size.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v5: New
---
 arch/powerpc/kernel/head_85xx.S | 30 ++++++++++++++++--------------
 1 file changed, 16 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/kernel/head_85xx.S b/arch/powerpc/kernel/head_85xx.S
index 282e49c51deb..226f88e77d6d 100644
--- a/arch/powerpc/kernel/head_85xx.S
+++ b/arch/powerpc/kernel/head_85xx.S
@@ -294,9 +294,10 @@ set_ivor:
 /* Macros to hide the PTE size differences
  *
  * FIND_PTE -- walks the page tables given EA & pgdir pointer
- *   r10 -- EA of fault
+ *   r10 -- free
  *   r11 -- PGDIR pointer
  *   r12 -- free
+ *   r13 -- EA of fault
  *   label 2: is the bailout case
  *
  * if we find the pte (fall through):
@@ -307,7 +308,7 @@ set_ivor:
 #ifdef CONFIG_PTE_64BIT
 #ifdef CONFIG_HUGETLB_PAGE
 #define FIND_PTE	\
-	rlwinm	r12, r10, 14, 18, 28;	/* Compute pgdir/pmd offset */	\
+	rlwinm	r12, r13, 14, 18, 28;	/* Compute pgdir/pmd offset */	\
 	add	r12, r11, r12;						\
 	lwz	r11, 4(r12);		/* Get pgd/pmd entry */		\
 	rlwinm.	r12, r11, 0, 0, 20;	/* Extract pt base address */	\
@@ -317,26 +318,26 @@ set_ivor:
 	andi.	r10, r11, HUGEPD_SHIFT_MASK@l; /* extract size field */	\
 	xor	r12, r10, r11;		/* drop size bits from pointer */ \
 	b	1001f;							\
-1000:	rlwimi	r12, r10, 23, 20, 28;	/* Compute pte address */	\
+1000:	rlwimi	r12, r13, 23, 20, 28;	/* Compute pte address */	\
 	li	r10, 0;			/* clear r10 */			\
 1001:	lwz	r11, 4(r12);		/* Get pte entry */
 #else
 #define FIND_PTE	\
-	rlwinm	r12, r10, 14, 18, 28;	/* Compute pgdir/pmd offset */	\
+	rlwinm	r12, r13, 14, 18, 28;	/* Compute pgdir/pmd offset */	\
 	add	r12, r11, r12;						\
 	lwz	r11, 4(r12);		/* Get pgd/pmd entry */		\
 	rlwinm.	r12, r11, 0, 0, 20;	/* Extract pt base address */	\
 	beq	2f;			/* Bail if no table */		\
-	rlwimi	r12, r10, 23, 20, 28;	/* Compute pte address */	\
+	rlwimi	r12, r13, 23, 20, 28;	/* Compute pte address */	\
 	lwz	r11, 4(r12);		/* Get pte entry */
 #endif /* HUGEPAGE */
 #else /* !PTE_64BIT */
 #define FIND_PTE	\
-	rlwimi	r11, r10, 12, 20, 29;	/* Create L1 (pgdir/pmd) address */	\
+	rlwimi	r11, r13, 12, 20, 29;	/* Create L1 (pgdir/pmd) address */	\
 	lwz	r11, 0(r11);		/* Get L1 entry */			\
 	rlwinm.	r12, r11, 0, 0, 19;	/* Extract L2 (pte) base address */	\
 	beq	2f;			/* Bail if no table */			\
-	rlwimi	r12, r10, 22, 20, 29;	/* Compute PTE address */		\
+	rlwimi	r12, r13, 22, 20, 29;	/* Compute PTE address */		\
 	lwz	r11, 0(r12);		/* Get Linux PTE */
 #endif
 
@@ -443,13 +444,13 @@ START_BTB_FLUSH_SECTION
 	BTB_FLUSH(r10)
 1:
 END_BTB_FLUSH_SECTION
-	mfspr	r10, SPRN_DEAR		/* Get faulting address */
+	mfspr	r13, SPRN_DEAR		/* Get faulting address */
 
 	/* If we are faulting a kernel address, we have to use the
 	 * kernel page tables.
 	 */
 	lis	r11, PAGE_OFFSET@h
-	cmplw	5, r10, r11
+	cmplw	5, r13, r11
 	blt	5, 3f
 	lis	r11, swapper_pg_dir@h
 	ori	r11, r11, swapper_pg_dir@l
@@ -472,14 +473,14 @@ END_BTB_FLUSH_SECTION
 #endif
 
 4:
+	FIND_PTE
+
 #ifdef CONFIG_PTE_64BIT
 	li	r13,_PAGE_PRESENT|_PAGE_BAP_SR
 	oris	r13,r13,_PAGE_ACCESSED@h
 #else
 	li	r13,_PAGE_PRESENT|_PAGE_READ|_PAGE_ACCESSED
 #endif
-
-	FIND_PTE
 	andc.	r13,r13,r11		/* Check permission */
 
 #ifdef CONFIG_PTE_64BIT
@@ -536,13 +537,13 @@ START_BTB_FLUSH_SECTION
 1:
 END_BTB_FLUSH_SECTION
 
-	mfspr	r10, SPRN_SRR0		/* Get faulting address */
+	mfspr	r13, SPRN_SRR0		/* Get faulting address */
 
 	/* If we are faulting a kernel address, we have to use the
 	 * kernel page tables.
 	 */
 	lis	r11, PAGE_OFFSET@h
-	cmplw	5, r10, r11
+	cmplw	5, r13, r11
 	blt	5, 3f
 	lis	r11, swapper_pg_dir@h
 	ori	r11, r11, swapper_pg_dir@l
@@ -551,6 +552,7 @@ END_BTB_FLUSH_SECTION
 	rlwinm	r12,r12,0,16,1
 	mtspr	SPRN_MAS1,r12
 
+	FIND_PTE
 	/* Make up the required permissions for kernel code */
 #ifdef CONFIG_PTE_64BIT
 	li	r13,_PAGE_PRESENT | _PAGE_BAP_SX
@@ -571,6 +573,7 @@ END_BTB_FLUSH_SECTION
 	beq	2f			/* KUAP fault */
 #endif
 
+	FIND_PTE
 	/* Make up the required permissions for user code */
 #ifdef CONFIG_PTE_64BIT
 	li	r13,_PAGE_PRESENT | _PAGE_BAP_UX
@@ -580,7 +583,6 @@ END_BTB_FLUSH_SECTION
 #endif
 
 4:
-	FIND_PTE
 	andc.	r13,r13,r11		/* Check permission */
 
 #ifdef CONFIG_PTE_64BIT
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 20/23] powerpc/e500: Use contiguous PMD instead of hugepd
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (18 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 19/23] powerpc/e500: Free r10 for FIND_PTE Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 21/23] powerpc/64s: Use contiguous PMD/PUD instead of HUGEPD Christophe Leroy
                   ` (2 subsequent siblings)
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

e500 supports many page sizes among which the following size are
implemented in the kernel at the time being: 4M, 16M, 64M, 256M, 1G.

On e500, TLB miss for hugepages is exclusively handled by SW even
on e6500 which has HW assistance for 4k pages, so there are no
constraints like on the 8xx.

On e500/32, all are at PGD/PMD level and can be handled as
cont-PMD.

On e500/64, smaller ones are on PMD while bigger ones are on PUD.
Again, they can easily be handled as cont-PMD and cont-PUD instead
of hugepd.

On e500/32, use the pagesize bits in PTE to know if it is a PMD or
a leaf entry. This works because the pagesize bits are in the last
12 bits and page tables are 4k aligned.

On e500/64, use highest bit which is always 1 on PxD (Because PxD
contains virtual address of a kernel memory) and always 0 on PTEs
because not all bits of RPN are used/possible.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
---
v3: Add missing pmd_leaf_size() and pud_leaf_size()
v4: Rebased of v6.10-rc1 : pmd_huge() and pud_huge() are gone
v5:
- Define pte_huge_size() to reduce redundant and handle the case of mpc85xx with 32 bits PTE.
- Replace hard-coded page shift offset (10) with new macro _PAGE_PSIZE_SHIFT_OFFSET
- Use TSIZE encoding in SIZE field in PTE
- On 64 bits, use highest bit to know if it is a PUD/PMD or leaf entry. Avoids problem with page table alignment.
---
 .../powerpc/include/asm/nohash/hugetlb-e500.h | 32 ++------------
 arch/powerpc/include/asm/nohash/pgalloc.h     |  2 -
 arch/powerpc/include/asm/nohash/pgtable.h     | 42 ++++++++++++++-----
 arch/powerpc/include/asm/nohash/pte-e500.h    | 33 +++++++++++++++
 arch/powerpc/include/asm/page.h               | 15 +------
 arch/powerpc/kernel/head_85xx.S               | 21 ++++------
 arch/powerpc/mm/hugetlbpage.c                 |  2 -
 arch/powerpc/mm/nohash/tlb_low_64e.S          |  7 +---
 arch/powerpc/mm/pgtable.c                     | 31 ++++++++++++++
 arch/powerpc/platforms/Kconfig.cputype        |  1 -
 10 files changed, 107 insertions(+), 79 deletions(-)

diff --git a/arch/powerpc/include/asm/nohash/hugetlb-e500.h b/arch/powerpc/include/asm/nohash/hugetlb-e500.h
index c6a0938e86fd..812c71fc5eb1 100644
--- a/arch/powerpc/include/asm/nohash/hugetlb-e500.h
+++ b/arch/powerpc/include/asm/nohash/hugetlb-e500.h
@@ -2,38 +2,12 @@
 #ifndef _ASM_POWERPC_NOHASH_HUGETLB_E500_H
 #define _ASM_POWERPC_NOHASH_HUGETLB_E500_H
 
-static inline pte_t *hugepd_page(hugepd_t hpd)
-{
-	if (WARN_ON(!hugepd_ok(hpd)))
-		return NULL;
-
-	return (pte_t *)((hpd_val(hpd) & ~HUGEPD_SHIFT_MASK) | PD_HUGE);
-}
-
-static inline unsigned int hugepd_shift(hugepd_t hpd)
-{
-	return hpd_val(hpd) & HUGEPD_SHIFT_MASK;
-}
-
-static inline pte_t *hugepte_offset(hugepd_t hpd, unsigned long addr,
-				    unsigned int pdshift)
-{
-	/*
-	 * On FSL BookE, we have multiple higher-level table entries that
-	 * point to the same hugepte.  Just use the first one since they're all
-	 * identical.  So for that case, idx=0.
-	 */
-	return hugepd_page(hpd);
-}
+#define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+		     pte_t pte, unsigned long sz);
 
 void flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
 
-static inline void hugepd_populate(hugepd_t *hpdp, pte_t *new, unsigned int pshift)
-{
-	/* We use the old format for PPC_E500 */
-	*hpdp = __hugepd(((unsigned long)new & ~PD_HUGE) | pshift);
-}
-
 static inline int check_and_get_huge_psize(int shift)
 {
 	if (shift & 1)	/* Not a power of 4 */
diff --git a/arch/powerpc/include/asm/nohash/pgalloc.h b/arch/powerpc/include/asm/nohash/pgalloc.h
index 4b62376318e1..d06efac6d7aa 100644
--- a/arch/powerpc/include/asm/nohash/pgalloc.h
+++ b/arch/powerpc/include/asm/nohash/pgalloc.h
@@ -44,8 +44,6 @@ static inline void pgtable_free(void *table, int shift)
 	}
 }
 
-#define get_hugepd_cache_index(x)	(x)
-
 static inline void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift)
 {
 	unsigned long pgf = (unsigned long)table;
diff --git a/arch/powerpc/include/asm/nohash/pgtable.h b/arch/powerpc/include/asm/nohash/pgtable.h
index 90d6a0943b35..8d1f0b7062eb 100644
--- a/arch/powerpc/include/asm/nohash/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/pgtable.h
@@ -31,6 +31,13 @@ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, p
 
 extern int icache_44x_need_flush;
 
+#ifndef pte_huge_size
+static inline unsigned long pte_huge_size(pte_t pte)
+{
+	return PAGE_SIZE;
+}
+#endif
+
 /*
  * PTE updates. This function is called whenever an existing
  * valid PTE is updated. This does -not- include set_pte_at()
@@ -52,11 +59,34 @@ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, p
 {
 	pte_basic_t old = pte_val(*p);
 	pte_basic_t new = (old & ~(pte_basic_t)clr) | set;
+	unsigned long sz;
+	unsigned long pdsize;
+	int i;
 
 	if (new == old)
 		return old;
 
-	*p = __pte(new);
+	if (huge)
+		sz = pte_huge_size(__pte(old));
+	else
+		sz = PAGE_SIZE;
+
+	if (sz < PMD_SIZE)
+		pdsize = PAGE_SIZE;
+	else if (sz < PUD_SIZE)
+		pdsize = PMD_SIZE;
+	else if (sz < P4D_SIZE)
+		pdsize = PUD_SIZE;
+	else if (sz < PGDIR_SIZE)
+		pdsize = P4D_SIZE;
+	else
+		pdsize = PGDIR_SIZE;
+
+	for (i = 0; i < sz / pdsize; i++, p++) {
+		*p = __pte(new);
+		if (new)
+			new += (unsigned long long)(pdsize / PAGE_SIZE) << PTE_RPN_SHIFT;
+	}
 
 	if (IS_ENABLED(CONFIG_44x) && !is_kernel_addr(addr) && (old & _PAGE_EXEC))
 		icache_44x_need_flush = 1;
@@ -340,16 +370,6 @@ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr,
 
 #define pgprot_writecombine pgprot_noncached_wc
 
-#ifdef CONFIG_ARCH_HAS_HUGEPD
-static inline int hugepd_ok(hugepd_t hpd)
-{
-	/* We clear the top bit to indicate hugepd */
-	return (hpd_val(hpd) && (hpd_val(hpd) & PD_HUGE) == 0);
-}
-
-#define is_hugepd(hpd)		(hugepd_ok(hpd))
-#endif
-
 int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot);
 void unmap_kernel_page(unsigned long va);
 
diff --git a/arch/powerpc/include/asm/nohash/pte-e500.h b/arch/powerpc/include/asm/nohash/pte-e500.h
index 6dac1c0a6937..cb78392494da 100644
--- a/arch/powerpc/include/asm/nohash/pte-e500.h
+++ b/arch/powerpc/include/asm/nohash/pte-e500.h
@@ -101,6 +101,39 @@ static inline unsigned long pte_huge_size(pte_t pte)
 }
 #define pte_huge_size pte_huge_size
 
+static inline int pmd_leaf(pmd_t pmd)
+{
+	if (IS_ENABLED(CONFIG_PPC64))
+		return (long)pmd_val(pmd) > 0;
+	else
+		return pmd_val(pmd) & _PAGE_PSIZE_MSK;
+}
+#define pmd_leaf pmd_leaf
+
+static inline unsigned long pmd_leaf_size(pmd_t pmd)
+{
+	return pte_huge_size(__pte(pmd_val(pmd)));
+}
+#define pmd_leaf_size pmd_leaf_size
+
+#ifdef CONFIG_PPC64
+static inline int pud_leaf(pud_t pud)
+{
+	if (IS_ENABLED(CONFIG_PPC64))
+		return (long)pud_val(pud) > 0;
+	else
+		return pud_val(pud) & _PAGE_PSIZE_MSK;
+}
+#define pud_leaf pud_leaf
+
+static inline unsigned long pud_leaf_size(pud_t pud)
+{
+	return pte_huge_size(__pte(pud_val(pud)));
+}
+#define pud_leaf_size pud_leaf_size
+
+#endif
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* __KERNEL__ */
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 018c3d55232c..7d3c3bc40e6a 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -269,20 +269,7 @@ static inline const void *pfn_to_kaddr(unsigned long pfn)
 #define is_kernel_addr(x)	((x) >= TASK_SIZE)
 #endif
 
-#ifndef CONFIG_PPC_BOOK3S_64
-/*
- * Use the top bit of the higher-level page table entries to indicate whether
- * the entries we point to contain hugepages.  This works because we know that
- * the page tables live in kernel space.  If we ever decide to support having
- * page tables at arbitrary addresses, this breaks and will have to change.
- */
-#ifdef CONFIG_PPC64
-#define PD_HUGE 0x8000000000000000UL
-#else
-#define PD_HUGE 0x80000000
-#endif
-
-#else	/* CONFIG_PPC_BOOK3S_64 */
+#ifdef CONFIG_PPC_BOOK3S_64
 /*
  * Book3S 64 stores real addresses in the hugepd entries to
  * avoid overlaps with _PAGE_PRESENT and _PAGE_PTE.
diff --git a/arch/powerpc/kernel/head_85xx.S b/arch/powerpc/kernel/head_85xx.S
index 226f88e77d6d..f9a73fae6464 100644
--- a/arch/powerpc/kernel/head_85xx.S
+++ b/arch/powerpc/kernel/head_85xx.S
@@ -311,16 +311,14 @@ set_ivor:
 	rlwinm	r12, r13, 14, 18, 28;	/* Compute pgdir/pmd offset */	\
 	add	r12, r11, r12;						\
 	lwz	r11, 4(r12);		/* Get pgd/pmd entry */		\
+	rlwinm.	r10, r11, 32 - _PAGE_PSIZE_SHIFT, 0x1e; /* get tsize*/	\
+	bne	1000f;			/* Huge page (leaf entry) */	\
 	rlwinm.	r12, r11, 0, 0, 20;	/* Extract pt base address */	\
-	blt	1000f;			/* Normal non-huge page */	\
 	beq	2f;			/* Bail if no table */		\
-	oris	r11, r11, PD_HUGE@h;	/* Put back address bit */	\
-	andi.	r10, r11, HUGEPD_SHIFT_MASK@l; /* extract size field */	\
-	xor	r12, r10, r11;		/* drop size bits from pointer */ \
-	b	1001f;							\
-1000:	rlwimi	r12, r13, 23, 20, 28;	/* Compute pte address */	\
+	rlwimi	r12, r13, 23, 20, 28;	/* Compute pte address */	\
 	li	r10, 0;			/* clear r10 */			\
-1001:	lwz	r11, 4(r12);		/* Get pte entry */
+	lwz	r11, 4(r12);		/* Get pte entry */		\
+1000:
 #else
 #define FIND_PTE	\
 	rlwinm	r12, r13, 14, 18, 28;	/* Compute pgdir/pmd offset */	\
@@ -735,17 +733,12 @@ finish_tlb_load:
 	lwz	r15, 0(r14)
 100:	stw	r15, 0(r17)
 
-	/*
-	 * Calc MAS1_TSIZE from r10 (which has pshift encoded)
-	 * tlb_enc = (pshift - 10).
-	 */
-	subi	r15, r10, 10
 	mfspr	r16, SPRN_MAS1
-	rlwimi	r16, r15, 7, 20, 24
+	rlwimi	r16, r10, MAS1_TSIZE_SHIFT, MAS1_TSIZE_MASK
 	mtspr	SPRN_MAS1, r16
 
 	/* copy the pshift for use later */
-	mr	r14, r10
+	addi	r14, r10, _PAGE_PSIZE_SHIFT_OFFSET
 
 	/* fall through */
 
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 394846197974..9e692d96f9e1 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -625,8 +625,6 @@ static int __init hugetlbpage_init(void)
 		 */
 		if (pdshift > shift) {
 			pgtable_cache_add(pdshift - shift);
-		} else if (IS_ENABLED(CONFIG_PPC_E500)) {
-			pgtable_cache_add(PTE_T_ORDER);
 		}
 
 		configured = true;
diff --git a/arch/powerpc/mm/nohash/tlb_low_64e.S b/arch/powerpc/mm/nohash/tlb_low_64e.S
index a54e7d6c3d0b..de568297d5c5 100644
--- a/arch/powerpc/mm/nohash/tlb_low_64e.S
+++ b/arch/powerpc/mm/nohash/tlb_low_64e.S
@@ -450,11 +450,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_SMT)
 
 tlb_miss_huge_e6500:
 	beq	tlb_miss_fault_e6500
-	li	r10,1
-	andi.	r15,r14,HUGEPD_SHIFT_MASK@l /* r15 = psize */
-	rldimi	r14,r10,63,0		/* Set PD_HUGE */
-	xor	r14,r14,r15		/* Clear size bits */
-	ldx	r14,0,r14
+	rlwinm	r15,r14,32-_PAGE_PSIZE_SHIFT,0x1e
 
 	/*
 	 * Now we build the MAS for a huge page.
@@ -465,7 +461,6 @@ tlb_miss_huge_e6500:
 	 * MAS 2,3+7:	Needs to be redone similar to non-tablewalk handler
 	 */
 
-	subi	r15,r15,10		/* Convert psize to tsize */
 	mfspr	r10,SPRN_MAS1
 	rlwinm	r10,r10,0,~MAS1_IND
 	rlwimi	r10,r15,MAS1_TSIZE_SHIFT,MAS1_TSIZE_MASK
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 294775c793ab..6498454959f3 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -331,6 +331,37 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 		__set_huge_pte_at(pmdp, ptep, pte_val(pte));
 	}
 }
+#elif defined(CONFIG_PPC_E500)
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+		     pte_t pte, unsigned long sz)
+{
+	unsigned long pdsize;
+	int i;
+
+	pte = set_pte_filter(pte, addr);
+
+	/*
+	 * Make sure hardware valid bit is not set. We don't do
+	 * tlb flush for this update.
+	 */
+	VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep));
+
+	if (sz < PMD_SIZE)
+		pdsize = PAGE_SIZE;
+	else if (sz < PUD_SIZE)
+		pdsize = PMD_SIZE;
+	else if (sz < P4D_SIZE)
+		pdsize = PUD_SIZE;
+	else if (sz < PGDIR_SIZE)
+		pdsize = P4D_SIZE;
+	else
+		pdsize = PGDIR_SIZE;
+
+	for (i = 0; i < sz / pdsize; i++, ptep++, addr += pdsize) {
+		__set_pte_at(mm, addr, ptep, pte, 0);
+		pte = __pte(pte_val(pte) + ((unsigned long long)pdsize / PAGE_SIZE << PFN_PTE_SHIFT));
+	}
+}
 #endif
 #endif /* CONFIG_HUGETLB_PAGE */
 
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index fa4bb096b3ae..30a78e99663e 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -291,7 +291,6 @@ config PPC_BOOK3S
 config PPC_E500
 	select FSL_EMB_PERFMON
 	bool
-	select ARCH_HAS_HUGEPD if HUGETLB_PAGE
 	select ARCH_SUPPORTS_HUGETLBFS if PHYS_64BIT || PPC64
 	select PPC_SMP_MUXED_IPI
 	select PPC_DOORBELL
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 21/23] powerpc/64s: Use contiguous PMD/PUD instead of HUGEPD
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (19 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 20/23] powerpc/e500: Use contiguous PMD instead of hugepd Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 22/23] powerpc/mm: Remove hugepd leftovers Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 23/23] mm: Remove CONFIG_ARCH_HAS_HUGEPD Christophe Leroy
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

On book3s/64, the only user of hugepd is hash in 4k mode.

All other setups (hash-64, radix-4, radix-64) use leaf PMD/PUD.

Rework hash-4k to use contiguous PMD and PUD instead.

In that setup there are only two huge page sizes: 16M and 16G.

16M sits at PMD level and 16G at PUD level.

pte_update doesn't know page size, lets use the same trick as
hpte_need_flush() to get page size from segment properties. That's
not the most efficient way but let's do that until callers of
pte_update() provide page size instead of just a huge flag.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
---
v3:
- Add missing pmd_leaf_size() and pud_leaf_size()
- More cleanup in hugetlbpage_init()
- Take a page fault when DIRTY or ACCESSED is missing on hash-4 hugepage

v4: Rebased on v6.10-rc1

v6: Added a WARN_ON_ONCE() in hash__pte_update() in case the pagesize is unexpected.
---
 arch/powerpc/include/asm/book3s/64/hash-4k.h  | 15 ------
 arch/powerpc/include/asm/book3s/64/hash.h     | 40 +++++++++++++---
 arch/powerpc/include/asm/book3s/64/hugetlb.h  | 38 ---------------
 .../include/asm/book3s/64/pgtable-4k.h        | 47 -------------------
 .../include/asm/book3s/64/pgtable-64k.h       | 20 --------
 arch/powerpc/include/asm/book3s/64/pgtable.h  | 22 +++++++--
 arch/powerpc/include/asm/hugetlb.h            |  4 ++
 .../powerpc/include/asm/nohash/hugetlb-e500.h |  4 --
 arch/powerpc/include/asm/page.h               |  8 ----
 arch/powerpc/mm/book3s64/hash_utils.c         | 11 +++--
 arch/powerpc/mm/book3s64/hugetlbpage.c        | 10 ++++
 arch/powerpc/mm/book3s64/pgtable.c            | 12 -----
 arch/powerpc/mm/hugetlbpage.c                 | 26 ----------
 arch/powerpc/mm/pgtable.c                     |  2 +-
 arch/powerpc/platforms/Kconfig.cputype        |  1 -
 15 files changed, 74 insertions(+), 186 deletions(-)
 delete mode 100644 arch/powerpc/include/asm/book3s/64/pgtable-4k.h

diff --git a/arch/powerpc/include/asm/book3s/64/hash-4k.h b/arch/powerpc/include/asm/book3s/64/hash-4k.h
index 6472b08fa1b0..c654c376ef8b 100644
--- a/arch/powerpc/include/asm/book3s/64/hash-4k.h
+++ b/arch/powerpc/include/asm/book3s/64/hash-4k.h
@@ -74,21 +74,6 @@
 #define remap_4k_pfn(vma, addr, pfn, prot)	\
 	remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE, (prot))
 
-#ifdef CONFIG_HUGETLB_PAGE
-static inline int hash__hugepd_ok(hugepd_t hpd)
-{
-	unsigned long hpdval = hpd_val(hpd);
-	/*
-	 * if it is not a pte and have hugepd shift mask
-	 * set, then it is a hugepd directory pointer
-	 */
-	if (!(hpdval & _PAGE_PTE) && (hpdval & _PAGE_PRESENT) &&
-	    ((hpdval & HUGEPD_SHIFT_MASK) != 0))
-		return true;
-	return false;
-}
-#endif
-
 /*
  * 4K PTE format is different from 64K PTE format. Saving the hash_slot is just
  * a matter of returning the PTE bits that need to be modified. On 64K PTE,
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index faf3e3b4e4b2..0755f2567021 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -4,6 +4,7 @@
 #ifdef __KERNEL__
 
 #include <asm/asm-const.h>
+#include <asm/book3s/64/slice.h>
 
 /*
  * Common bits between 4K and 64K pages in a linux-style PTE.
@@ -161,14 +162,10 @@ extern void hpte_need_flush(struct mm_struct *mm, unsigned long addr,
 			    pte_t *ptep, unsigned long pte, int huge);
 unsigned long htab_convert_pte_flags(unsigned long pteflags, unsigned long flags);
 /* Atomic PTE updates */
-static inline unsigned long hash__pte_update(struct mm_struct *mm,
-					 unsigned long addr,
-					 pte_t *ptep, unsigned long clr,
-					 unsigned long set,
-					 int huge)
+static inline unsigned long hash__pte_update_one(pte_t *ptep, unsigned long clr,
+						 unsigned long set)
 {
 	__be64 old_be, tmp_be;
-	unsigned long old;
 
 	__asm__ __volatile__(
 	"1:	ldarx	%0,0,%3		# pte_update\n\
@@ -182,11 +179,40 @@ static inline unsigned long hash__pte_update(struct mm_struct *mm,
 	: "r" (ptep), "r" (cpu_to_be64(clr)), "m" (*ptep),
 	  "r" (cpu_to_be64(H_PAGE_BUSY)), "r" (cpu_to_be64(set))
 	: "cc" );
+
+	return be64_to_cpu(old_be);
+}
+
+static inline unsigned long hash__pte_update(struct mm_struct *mm,
+					 unsigned long addr,
+					 pte_t *ptep, unsigned long clr,
+					 unsigned long set,
+					 int huge)
+{
+	unsigned long old;
+
+	old = hash__pte_update_one(ptep, clr, set);
+
+	if (IS_ENABLED(CONFIG_PPC_4K_PAGES) && huge) {
+		unsigned int psize = get_slice_psize(mm, addr);
+		int nb, i;
+
+		if (psize == MMU_PAGE_16M)
+			nb = SZ_16M / PMD_SIZE;
+		else if (psize == MMU_PAGE_16G)
+			nb = SZ_16G / PUD_SIZE;
+		else
+			nb = 1;
+
+		WARN_ON_ONCE(nb == 1);	/* Should never happen */
+
+		for (i = 1; i < nb; i++)
+			hash__pte_update_one(ptep + i, clr, set);
+	}
 	/* huge pages use the old page table lock */
 	if (!huge)
 		assert_pte_locked(mm, addr);
 
-	old = be64_to_cpu(old_be);
 	if (old & H_PAGE_HASHPTE)
 		hpte_need_flush(mm, addr, ptep, old, huge);
 
diff --git a/arch/powerpc/include/asm/book3s/64/hugetlb.h b/arch/powerpc/include/asm/book3s/64/hugetlb.h
index aa1c67c8bfc8..f0bba9c5f9c3 100644
--- a/arch/powerpc/include/asm/book3s/64/hugetlb.h
+++ b/arch/powerpc/include/asm/book3s/64/hugetlb.h
@@ -49,9 +49,6 @@ static inline bool gigantic_page_runtime_supported(void)
 	return true;
 }
 
-/* hugepd entry valid bit */
-#define HUGEPD_VAL_BITS		(0x8000000000000000UL)
-
 #define huge_ptep_modify_prot_start huge_ptep_modify_prot_start
 extern pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
 					 unsigned long addr, pte_t *ptep);
@@ -60,29 +57,7 @@ extern pte_t huge_ptep_modify_prot_start(struct vm_area_struct *vma,
 extern void huge_ptep_modify_prot_commit(struct vm_area_struct *vma,
 					 unsigned long addr, pte_t *ptep,
 					 pte_t old_pte, pte_t new_pte);
-/*
- * This should work for other subarchs too. But right now we use the
- * new format only for 64bit book3s
- */
-static inline pte_t *hugepd_page(hugepd_t hpd)
-{
-	BUG_ON(!hugepd_ok(hpd));
-	/*
-	 * We have only four bits to encode, MMU page size
-	 */
-	BUILD_BUG_ON((MMU_PAGE_COUNT - 1) > 0xf);
-	return __va(hpd_val(hpd) & HUGEPD_ADDR_MASK);
-}
-
-static inline unsigned int hugepd_mmu_psize(hugepd_t hpd)
-{
-	return (hpd_val(hpd) & HUGEPD_SHIFT_MASK) >> 2;
-}
 
-static inline unsigned int hugepd_shift(hugepd_t hpd)
-{
-	return mmu_psize_to_shift(hugepd_mmu_psize(hpd));
-}
 static inline void flush_hugetlb_page(struct vm_area_struct *vma,
 				      unsigned long vmaddr)
 {
@@ -90,19 +65,6 @@ static inline void flush_hugetlb_page(struct vm_area_struct *vma,
 		return radix__flush_hugetlb_page(vma, vmaddr);
 }
 
-static inline pte_t *hugepte_offset(hugepd_t hpd, unsigned long addr,
-				    unsigned int pdshift)
-{
-	unsigned long idx = (addr & ((1UL << pdshift) - 1)) >> hugepd_shift(hpd);
-
-	return hugepd_page(hpd) + idx;
-}
-
-static inline void hugepd_populate(hugepd_t *hpdp, pte_t *new, unsigned int pshift)
-{
-	*hpdp = __hugepd(__pa(new) | HUGEPD_VAL_BITS | (shift_to_mmu_psize(pshift) << 2));
-}
-
 void flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
 
 static inline int check_and_get_huge_psize(int shift)
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable-4k.h b/arch/powerpc/include/asm/book3s/64/pgtable-4k.h
deleted file mode 100644
index baf934578c3a..000000000000
--- a/arch/powerpc/include/asm/book3s/64/pgtable-4k.h
+++ /dev/null
@@ -1,47 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _ASM_POWERPC_BOOK3S_64_PGTABLE_4K_H
-#define _ASM_POWERPC_BOOK3S_64_PGTABLE_4K_H
-/*
- * hash 4k can't share hugetlb and also doesn't support THP
- */
-#ifndef __ASSEMBLY__
-#ifdef CONFIG_HUGETLB_PAGE
-/*
- * With radix , we have hugepage ptes in the pud and pmd entries. We don't
- * need to setup hugepage directory for them. Our pte and page directory format
- * enable us to have this enabled.
- */
-static inline int hugepd_ok(hugepd_t hpd)
-{
-	if (radix_enabled())
-		return 0;
-	return hash__hugepd_ok(hpd);
-}
-#define is_hugepd(hpd)		(hugepd_ok(hpd))
-
-/*
- * 16M and 16G huge page directory tables are allocated from slab cache
- *
- */
-#define H_16M_CACHE_INDEX (PAGE_SHIFT + H_PTE_INDEX_SIZE + H_PMD_INDEX_SIZE - 24)
-#define H_16G_CACHE_INDEX                                                      \
-	(PAGE_SHIFT + H_PTE_INDEX_SIZE + H_PMD_INDEX_SIZE + H_PUD_INDEX_SIZE - 34)
-
-static inline int get_hugepd_cache_index(int index)
-{
-	switch (index) {
-	case H_16M_CACHE_INDEX:
-		return HTLB_16M_INDEX;
-	case H_16G_CACHE_INDEX:
-		return HTLB_16G_INDEX;
-	default:
-		BUG();
-	}
-	/* should not reach */
-}
-
-#endif /* CONFIG_HUGETLB_PAGE */
-
-#endif /* __ASSEMBLY__ */
-
-#endif /*_ASM_POWERPC_BOOK3S_64_PGTABLE_4K_H */
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable-64k.h b/arch/powerpc/include/asm/book3s/64/pgtable-64k.h
index 6ac73da7b80e..4d8d7b4ea16b 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable-64k.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable-64k.h
@@ -5,26 +5,6 @@
 #ifndef __ASSEMBLY__
 #ifdef CONFIG_HUGETLB_PAGE
 
-/*
- * With 64k page size, we have hugepage ptes in the pgd and pmd entries. We don't
- * need to setup hugepage directory for them. Our pte and page directory format
- * enable us to have this enabled.
- */
-static inline int hugepd_ok(hugepd_t hpd)
-{
-	return 0;
-}
-
-#define is_hugepd(pdep)			0
-
-/*
- * This should never get called
- */
-static __always_inline int get_hugepd_cache_index(int index)
-{
-	BUILD_BUG();
-}
-
 #endif /* CONFIG_HUGETLB_PAGE */
 
 static inline int remap_4k_pfn(struct vm_area_struct *vma, unsigned long addr,
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index 8f9432e3855a..519b1743a0f4 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -274,6 +274,24 @@ static inline bool pud_leaf(pud_t pud)
 {
 	return !!(pud_raw(pud) & cpu_to_be64(_PAGE_PTE));
 }
+
+#define pmd_leaf_size pmd_leaf_size
+static inline unsigned long pmd_leaf_size(pmd_t pmd)
+{
+	if (IS_ENABLED(CONFIG_PPC_4K_PAGES) && !radix_enabled())
+		return SZ_16M;
+	else
+		return PMD_SIZE;
+}
+
+#define pud_leaf_size pud_leaf_size
+static inline unsigned long pud_leaf_size(pud_t pud)
+{
+	if (IS_ENABLED(CONFIG_PPC_4K_PAGES) && !radix_enabled())
+		return SZ_16G;
+	else
+		return PUD_SIZE;
+}
 #endif /* __ASSEMBLY__ */
 
 #include <asm/book3s/64/hash.h>
@@ -285,11 +303,9 @@ static inline bool pud_leaf(pud_t pud)
 #define  MAX_PHYSMEM_BITS	R_MAX_PHYSMEM_BITS
 #endif
 
-
+/* hash 4k can't share hugetlb and also doesn't support THP */
 #ifdef CONFIG_PPC_64K_PAGES
 #include <asm/book3s/64/pgtable-64k.h>
-#else
-#include <asm/book3s/64/pgtable-4k.h>
 #endif
 
 #include <asm/barrier.h>
diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index 79176a499763..e959c26c0b52 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -37,6 +37,10 @@ void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
 			    unsigned long ceiling);
 #endif
 
+#define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
+void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
+		     pte_t pte, unsigned long sz);
+
 #define __HAVE_ARCH_HUGE_PTEP_GET_AND_CLEAR
 static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
 					    unsigned long addr, pte_t *ptep)
diff --git a/arch/powerpc/include/asm/nohash/hugetlb-e500.h b/arch/powerpc/include/asm/nohash/hugetlb-e500.h
index 812c71fc5eb1..cab0e1f1eea0 100644
--- a/arch/powerpc/include/asm/nohash/hugetlb-e500.h
+++ b/arch/powerpc/include/asm/nohash/hugetlb-e500.h
@@ -2,10 +2,6 @@
 #ifndef _ASM_POWERPC_NOHASH_HUGETLB_E500_H
 #define _ASM_POWERPC_NOHASH_HUGETLB_E500_H
 
-#define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
-void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
-		     pte_t pte, unsigned long sz);
-
 void flush_hugetlb_page(struct vm_area_struct *vma, unsigned long vmaddr);
 
 static inline int check_and_get_huge_psize(int shift)
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index 7d3c3bc40e6a..c0af246a64ff 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -269,14 +269,6 @@ static inline const void *pfn_to_kaddr(unsigned long pfn)
 #define is_kernel_addr(x)	((x) >= TASK_SIZE)
 #endif
 
-#ifdef CONFIG_PPC_BOOK3S_64
-/*
- * Book3S 64 stores real addresses in the hugepd entries to
- * avoid overlaps with _PAGE_PRESENT and _PAGE_PTE.
- */
-#define HUGEPD_ADDR_MASK	(0x0ffffffffffffffful & ~HUGEPD_SHIFT_MASK)
-#endif /* CONFIG_PPC_BOOK3S_64 */
-
 /*
  * Some number of bits at the level of the page table that points to
  * a hugepte are used to encode the size.  This masks those bits.
diff --git a/arch/powerpc/mm/book3s64/hash_utils.c b/arch/powerpc/mm/book3s64/hash_utils.c
index 01c3b4b65241..6727a15ab94f 100644
--- a/arch/powerpc/mm/book3s64/hash_utils.c
+++ b/arch/powerpc/mm/book3s64/hash_utils.c
@@ -1233,10 +1233,6 @@ void __init hash__early_init_mmu(void)
 	__pmd_table_size = H_PMD_TABLE_SIZE;
 	__pud_table_size = H_PUD_TABLE_SIZE;
 	__pgd_table_size = H_PGD_TABLE_SIZE;
-	/*
-	 * 4k use hugepd format, so for hash set then to
-	 * zero
-	 */
 	__pmd_val_bits = HASH_PMD_VAL_BITS;
 	__pud_val_bits = HASH_PUD_VAL_BITS;
 	__pgd_val_bits = HASH_PGD_VAL_BITS;
@@ -1546,6 +1542,13 @@ int hash_page_mm(struct mm_struct *mm, unsigned long ea,
 		goto bail;
 	}
 
+	if (IS_ENABLED(CONFIG_PPC_4K_PAGES) && !radix_enabled()) {
+		if (hugeshift == PMD_SHIFT && psize == MMU_PAGE_16M)
+			hugeshift = mmu_psize_defs[MMU_PAGE_16M].shift;
+		if (hugeshift == PUD_SHIFT && psize == MMU_PAGE_16G)
+			hugeshift = mmu_psize_defs[MMU_PAGE_16G].shift;
+	}
+
 	/*
 	 * Add _PAGE_PRESENT to the required access perm. If there are parallel
 	 * updates to the pte that can possibly clear _PAGE_PTE, catch that too.
diff --git a/arch/powerpc/mm/book3s64/hugetlbpage.c b/arch/powerpc/mm/book3s64/hugetlbpage.c
index 5a2e512e96db..83c3361b358b 100644
--- a/arch/powerpc/mm/book3s64/hugetlbpage.c
+++ b/arch/powerpc/mm/book3s64/hugetlbpage.c
@@ -53,6 +53,16 @@ int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
 		/* If PTE permissions don't match, take page fault */
 		if (unlikely(!check_pte_access(access, old_pte)))
 			return 1;
+		/*
+		 * If hash-4k, hugepages use seeral contiguous PxD entries
+		 * so bail out and let mm make the page young or dirty
+		 */
+		if (IS_ENABLED(CONFIG_PPC_4K_PAGES)) {
+			if (!(old_pte & _PAGE_ACCESSED))
+				return 1;
+			if ((access & _PAGE_WRITE) && !(old_pte & _PAGE_DIRTY))
+				return 1;
+		}
 
 		/*
 		 * Try to lock the PTE, add ACCESSED and DIRTY if it was
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 2975ea0841ba..f4d8d3c40e5c 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -461,18 +461,6 @@ static inline void pgtable_free(void *table, int index)
 	case PUD_INDEX:
 		__pud_free(table);
 		break;
-#if defined(CONFIG_PPC_4K_PAGES) && defined(CONFIG_HUGETLB_PAGE)
-		/* 16M hugepd directory at pud level */
-	case HTLB_16M_INDEX:
-		BUILD_BUG_ON(H_16M_CACHE_INDEX <= 0);
-		kmem_cache_free(PGT_CACHE(H_16M_CACHE_INDEX), table);
-		break;
-		/* 16G hugepd directory at the pgd level */
-	case HTLB_16G_INDEX:
-		BUILD_BUG_ON(H_16G_CACHE_INDEX <= 0);
-		kmem_cache_free(PGT_CACHE(H_16G_CACHE_INDEX), table);
-		break;
-#endif
 		/* We don't free pgd table via RCU callback */
 	default:
 		BUG();
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 9e692d96f9e1..1fe2843f5b12 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -592,40 +592,14 @@ static int __init hugetlbpage_init(void)
 
 	for (psize = 0; psize < MMU_PAGE_COUNT; ++psize) {
 		unsigned shift;
-		unsigned pdshift;
 
 		if (!mmu_psize_defs[psize].shift)
 			continue;
 
 		shift = mmu_psize_to_shift(psize);
 
-#ifdef CONFIG_PPC_BOOK3S_64
-		if (shift > PGDIR_SHIFT)
-			continue;
-		else if (shift > PUD_SHIFT)
-			pdshift = PGDIR_SHIFT;
-		else if (shift > PMD_SHIFT)
-			pdshift = PUD_SHIFT;
-		else
-			pdshift = PMD_SHIFT;
-#else
-		if (shift < PUD_SHIFT)
-			pdshift = PMD_SHIFT;
-		else if (shift < PGDIR_SHIFT)
-			pdshift = PUD_SHIFT;
-		else
-			pdshift = PGDIR_SHIFT;
-#endif
-
 		if (add_huge_page_size(1ULL << shift) < 0)
 			continue;
-		/*
-		 * if we have pdshift and shift value same, we don't
-		 * use pgt cache for hugepd.
-		 */
-		if (pdshift > shift) {
-			pgtable_cache_add(pdshift - shift);
-		}
 
 		configured = true;
 	}
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 6498454959f3..218792cb2c47 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -331,7 +331,7 @@ void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 		__set_huge_pte_at(pmdp, ptep, pte_val(pte));
 	}
 }
-#elif defined(CONFIG_PPC_E500)
+#else
 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 		     pte_t pte, unsigned long sz)
 {
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 30a78e99663e..b2d8c0da2ad9 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -98,7 +98,6 @@ config PPC_BOOK3S_64
 	select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
 	select ARCH_ENABLE_SPLIT_PMD_PTLOCK
 	select ARCH_ENABLE_THP_MIGRATION if TRANSPARENT_HUGEPAGE
-	select ARCH_HAS_HUGEPD if HUGETLB_PAGE
 	select ARCH_SUPPORTS_HUGETLBFS
 	select ARCH_SUPPORTS_NUMA_BALANCING
 	select HAVE_MOVE_PMD
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 22/23] powerpc/mm: Remove hugepd leftovers
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (20 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 21/23] powerpc/64s: Use contiguous PMD/PUD instead of HUGEPD Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  2024-07-02 13:51 ` [PATCH v7 23/23] mm: Remove CONFIG_ARCH_HAS_HUGEPD Christophe Leroy
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

All targets have now opted out of CONFIG_ARCH_HAS_HUGEPD so
remove left over code.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Oscar Salvador <osalvador@suse.de>
---
v5: Fix a forgotten #endif which ended up in following patch
---
 arch/powerpc/include/asm/hugetlb.h          |   7 -
 arch/powerpc/include/asm/page.h             |   6 -
 arch/powerpc/include/asm/pgtable-be-types.h |  10 -
 arch/powerpc/include/asm/pgtable-types.h    |   9 -
 arch/powerpc/mm/hugetlbpage.c               | 413 --------------------
 arch/powerpc/mm/init-common.c               |   8 +-
 arch/powerpc/mm/pgtable.c                   |  27 +-
 7 files changed, 3 insertions(+), 477 deletions(-)

diff --git a/arch/powerpc/include/asm/hugetlb.h b/arch/powerpc/include/asm/hugetlb.h
index e959c26c0b52..18a3028ac3b6 100644
--- a/arch/powerpc/include/asm/hugetlb.h
+++ b/arch/powerpc/include/asm/hugetlb.h
@@ -30,13 +30,6 @@ static inline int is_hugepage_only_range(struct mm_struct *mm,
 }
 #define is_hugepage_only_range is_hugepage_only_range
 
-#ifdef CONFIG_ARCH_HAS_HUGEPD
-#define __HAVE_ARCH_HUGETLB_FREE_PGD_RANGE
-void hugetlb_free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
-			    unsigned long end, unsigned long floor,
-			    unsigned long ceiling);
-#endif
-
 #define __HAVE_ARCH_HUGE_SET_HUGE_PTE_AT
 void set_huge_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep,
 		     pte_t pte, unsigned long sz);
diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
index c0af246a64ff..83d0a4fc5f75 100644
--- a/arch/powerpc/include/asm/page.h
+++ b/arch/powerpc/include/asm/page.h
@@ -269,12 +269,6 @@ static inline const void *pfn_to_kaddr(unsigned long pfn)
 #define is_kernel_addr(x)	((x) >= TASK_SIZE)
 #endif
 
-/*
- * Some number of bits at the level of the page table that points to
- * a hugepte are used to encode the size.  This masks those bits.
- */
-#define HUGEPD_SHIFT_MASK     0x3f
-
 #ifndef __ASSEMBLY__
 
 #ifdef CONFIG_PPC_BOOK3S_64
diff --git a/arch/powerpc/include/asm/pgtable-be-types.h b/arch/powerpc/include/asm/pgtable-be-types.h
index 82633200b500..6bd8f89b25dc 100644
--- a/arch/powerpc/include/asm/pgtable-be-types.h
+++ b/arch/powerpc/include/asm/pgtable-be-types.h
@@ -101,14 +101,4 @@ static inline bool pmd_xchg(pmd_t *pmdp, pmd_t old, pmd_t new)
 	return pmd_raw(old) == prev;
 }
 
-#ifdef CONFIG_ARCH_HAS_HUGEPD
-typedef struct { __be64 pdbe; } hugepd_t;
-#define __hugepd(x) ((hugepd_t) { cpu_to_be64(x) })
-
-static inline unsigned long hpd_val(hugepd_t x)
-{
-	return be64_to_cpu(x.pdbe);
-}
-#endif
-
 #endif /* _ASM_POWERPC_PGTABLE_BE_TYPES_H */
diff --git a/arch/powerpc/include/asm/pgtable-types.h b/arch/powerpc/include/asm/pgtable-types.h
index db965d98e0ae..7b3d4c592a10 100644
--- a/arch/powerpc/include/asm/pgtable-types.h
+++ b/arch/powerpc/include/asm/pgtable-types.h
@@ -87,13 +87,4 @@ static inline bool pte_xchg(pte_t *ptep, pte_t old, pte_t new)
 }
 #endif
 
-#ifdef CONFIG_ARCH_HAS_HUGEPD
-typedef struct { unsigned long pd; } hugepd_t;
-#define __hugepd(x) ((hugepd_t) { (x) })
-static inline unsigned long hpd_val(hugepd_t x)
-{
-	return x.pd;
-}
-#endif
-
 #endif /* _ASM_POWERPC_PGTABLE_TYPES_H */
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 1fe2843f5b12..6b043180220a 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -28,8 +28,6 @@
 
 bool hugetlb_disabled = false;
 
-#define hugepd_none(hpd)	(hpd_val(hpd) == 0)
-
 #define PTE_T_ORDER	(__builtin_ffs(sizeof(pte_basic_t)) - \
 			 __builtin_ffs(sizeof(void *)))
 
@@ -42,156 +40,6 @@ pte_t *huge_pte_offset(struct mm_struct *mm, unsigned long addr, unsigned long s
 	return __find_linux_pte(mm->pgd, addr, NULL, NULL);
 }
 
-#ifdef CONFIG_ARCH_HAS_HUGEPD
-static int __hugepte_alloc(struct mm_struct *mm, hugepd_t *hpdp,
-			   unsigned long address, unsigned int pdshift,
-			   unsigned int pshift, spinlock_t *ptl)
-{
-	struct kmem_cache *cachep;
-	pte_t *new;
-	int i;
-	int num_hugepd;
-
-	if (pshift >= pdshift) {
-		cachep = PGT_CACHE(PTE_T_ORDER);
-		num_hugepd = 1 << (pshift - pdshift);
-	} else {
-		cachep = PGT_CACHE(pdshift - pshift);
-		num_hugepd = 1;
-	}
-
-	if (!cachep) {
-		WARN_ONCE(1, "No page table cache created for hugetlb tables");
-		return -ENOMEM;
-	}
-
-	new = kmem_cache_alloc(cachep, pgtable_gfp_flags(mm, GFP_KERNEL));
-
-	BUG_ON(pshift > HUGEPD_SHIFT_MASK);
-	BUG_ON((unsigned long)new & HUGEPD_SHIFT_MASK);
-
-	if (!new)
-		return -ENOMEM;
-
-	/*
-	 * Make sure other cpus find the hugepd set only after a
-	 * properly initialized page table is visible to them.
-	 * For more details look for comment in __pte_alloc().
-	 */
-	smp_wmb();
-
-	spin_lock(ptl);
-	/*
-	 * We have multiple higher-level entries that point to the same
-	 * actual pte location.  Fill in each as we go and backtrack on error.
-	 * We need all of these so the DTLB pgtable walk code can find the
-	 * right higher-level entry without knowing if it's a hugepage or not.
-	 */
-	for (i = 0; i < num_hugepd; i++, hpdp++) {
-		if (unlikely(!hugepd_none(*hpdp)))
-			break;
-		hugepd_populate(hpdp, new, pshift);
-	}
-	/* If we bailed from the for loop early, an error occurred, clean up */
-	if (i < num_hugepd) {
-		for (i = i - 1 ; i >= 0; i--, hpdp--)
-			*hpdp = __hugepd(0);
-		kmem_cache_free(cachep, new);
-	} else {
-		kmemleak_ignore(new);
-	}
-	spin_unlock(ptl);
-	return 0;
-}
-
-/*
- * At this point we do the placement change only for BOOK3S 64. This would
- * possibly work on other subarchs.
- */
-pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
-		      unsigned long addr, unsigned long sz)
-{
-	pgd_t *pg;
-	p4d_t *p4;
-	pud_t *pu;
-	pmd_t *pm;
-	hugepd_t *hpdp = NULL;
-	unsigned pshift = __ffs(sz);
-	unsigned pdshift = PGDIR_SHIFT;
-	spinlock_t *ptl;
-
-	addr &= ~(sz-1);
-	pg = pgd_offset(mm, addr);
-	p4 = p4d_offset(pg, addr);
-
-#ifdef CONFIG_PPC_BOOK3S_64
-	if (pshift == PGDIR_SHIFT)
-		/* 16GB huge page */
-		return (pte_t *) p4;
-	else if (pshift > PUD_SHIFT) {
-		/*
-		 * We need to use hugepd table
-		 */
-		ptl = &mm->page_table_lock;
-		hpdp = (hugepd_t *)p4;
-	} else {
-		pdshift = PUD_SHIFT;
-		pu = pud_alloc(mm, p4, addr);
-		if (!pu)
-			return NULL;
-		if (pshift == PUD_SHIFT)
-			return (pte_t *)pu;
-		else if (pshift > PMD_SHIFT) {
-			ptl = pud_lockptr(mm, pu);
-			hpdp = (hugepd_t *)pu;
-		} else {
-			pdshift = PMD_SHIFT;
-			pm = pmd_alloc(mm, pu, addr);
-			if (!pm)
-				return NULL;
-			if (pshift == PMD_SHIFT)
-				/* 16MB hugepage */
-				return (pte_t *)pm;
-			else {
-				ptl = pmd_lockptr(mm, pm);
-				hpdp = (hugepd_t *)pm;
-			}
-		}
-	}
-#else
-	if (pshift >= PGDIR_SHIFT) {
-		ptl = &mm->page_table_lock;
-		hpdp = (hugepd_t *)p4;
-	} else {
-		pdshift = PUD_SHIFT;
-		pu = pud_alloc(mm, p4, addr);
-		if (!pu)
-			return NULL;
-		if (pshift >= PUD_SHIFT) {
-			ptl = pud_lockptr(mm, pu);
-			hpdp = (hugepd_t *)pu;
-		} else {
-			pdshift = PMD_SHIFT;
-			pm = pmd_alloc(mm, pu, addr);
-			if (!pm)
-				return NULL;
-			ptl = pmd_lockptr(mm, pm);
-			hpdp = (hugepd_t *)pm;
-		}
-	}
-#endif
-	if (!hpdp)
-		return NULL;
-
-	BUG_ON(!hugepd_none(*hpdp) && !hugepd_ok(*hpdp));
-
-	if (hugepd_none(*hpdp) && __hugepte_alloc(mm, hpdp, addr,
-						  pdshift, pshift, ptl))
-		return NULL;
-
-	return hugepte_offset(*hpdp, addr, pdshift);
-}
-#else
 pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
 		      unsigned long addr, unsigned long sz)
 {
@@ -230,7 +78,6 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
 
 	return pte_alloc_huge(mm, pmd, addr);
 }
-#endif
 
 #ifdef CONFIG_PPC_BOOK3S_64
 /*
@@ -286,266 +133,6 @@ int __init alloc_bootmem_huge_page(struct hstate *h, int nid)
 	return __alloc_bootmem_huge_page(h, nid);
 }
 
-#ifdef CONFIG_ARCH_HAS_HUGEPD
-#ifndef CONFIG_PPC_BOOK3S_64
-#define HUGEPD_FREELIST_SIZE \
-	((PAGE_SIZE - sizeof(struct hugepd_freelist)) / sizeof(pte_t))
-
-struct hugepd_freelist {
-	struct rcu_head	rcu;
-	unsigned int index;
-	void *ptes[];
-};
-
-static DEFINE_PER_CPU(struct hugepd_freelist *, hugepd_freelist_cur);
-
-static void hugepd_free_rcu_callback(struct rcu_head *head)
-{
-	struct hugepd_freelist *batch =
-		container_of(head, struct hugepd_freelist, rcu);
-	unsigned int i;
-
-	for (i = 0; i < batch->index; i++)
-		kmem_cache_free(PGT_CACHE(PTE_T_ORDER), batch->ptes[i]);
-
-	free_page((unsigned long)batch);
-}
-
-static void hugepd_free(struct mmu_gather *tlb, void *hugepte)
-{
-	struct hugepd_freelist **batchp;
-
-	batchp = &get_cpu_var(hugepd_freelist_cur);
-
-	if (atomic_read(&tlb->mm->mm_users) < 2 ||
-	    mm_is_thread_local(tlb->mm)) {
-		kmem_cache_free(PGT_CACHE(PTE_T_ORDER), hugepte);
-		put_cpu_var(hugepd_freelist_cur);
-		return;
-	}
-
-	if (*batchp == NULL) {
-		*batchp = (struct hugepd_freelist *)__get_free_page(GFP_ATOMIC);
-		(*batchp)->index = 0;
-	}
-
-	(*batchp)->ptes[(*batchp)->index++] = hugepte;
-	if ((*batchp)->index == HUGEPD_FREELIST_SIZE) {
-		call_rcu(&(*batchp)->rcu, hugepd_free_rcu_callback);
-		*batchp = NULL;
-	}
-	put_cpu_var(hugepd_freelist_cur);
-}
-#else
-static inline void hugepd_free(struct mmu_gather *tlb, void *hugepte) {}
-#endif
-
-/* Return true when the entry to be freed maps more than the area being freed */
-static bool range_is_outside_limits(unsigned long start, unsigned long end,
-				    unsigned long floor, unsigned long ceiling,
-				    unsigned long mask)
-{
-	if ((start & mask) < floor)
-		return true;
-	if (ceiling) {
-		ceiling &= mask;
-		if (!ceiling)
-			return true;
-	}
-	return end - 1 > ceiling - 1;
-}
-
-static void free_hugepd_range(struct mmu_gather *tlb, hugepd_t *hpdp, int pdshift,
-			      unsigned long start, unsigned long end,
-			      unsigned long floor, unsigned long ceiling)
-{
-	pte_t *hugepte = hugepd_page(*hpdp);
-	int i;
-
-	unsigned long pdmask = ~((1UL << pdshift) - 1);
-	unsigned int num_hugepd = 1;
-	unsigned int shift = hugepd_shift(*hpdp);
-
-	/* Note: On fsl the hpdp may be the first of several */
-	if (shift > pdshift)
-		num_hugepd = 1 << (shift - pdshift);
-
-	if (range_is_outside_limits(start, end, floor, ceiling, pdmask))
-		return;
-
-	for (i = 0; i < num_hugepd; i++, hpdp++)
-		*hpdp = __hugepd(0);
-
-	if (shift >= pdshift)
-		hugepd_free(tlb, hugepte);
-	else
-		pgtable_free_tlb(tlb, hugepte,
-				 get_hugepd_cache_index(pdshift - shift));
-}
-
-static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
-				   unsigned long addr, unsigned long end,
-				   unsigned long floor, unsigned long ceiling)
-{
-	pgtable_t token = pmd_pgtable(*pmd);
-
-	if (range_is_outside_limits(addr, end, floor, ceiling, PMD_MASK))
-		return;
-
-	pmd_clear(pmd);
-	pte_free_tlb(tlb, token, addr);
-	mm_dec_nr_ptes(tlb->mm);
-}
-
-static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
-				   unsigned long addr, unsigned long end,
-				   unsigned long floor, unsigned long ceiling)
-{
-	pmd_t *pmd;
-	unsigned long next;
-	unsigned long start;
-
-	start = addr;
-	do {
-		unsigned long more;
-
-		pmd = pmd_offset(pud, addr);
-		next = pmd_addr_end(addr, end);
-		if (!is_hugepd(__hugepd(pmd_val(*pmd)))) {
-			if (pmd_none_or_clear_bad(pmd))
-				continue;
-
-			/*
-			 * if it is not hugepd pointer, we should already find
-			 * it cleared.
-			 */
-			WARN_ON(!IS_ENABLED(CONFIG_PPC_8xx));
-
-			hugetlb_free_pte_range(tlb, pmd, addr, end, floor, ceiling);
-
-			continue;
-		}
-		/*
-		 * Increment next by the size of the huge mapping since
-		 * there may be more than one entry at this level for a
-		 * single hugepage, but all of them point to
-		 * the same kmem cache that holds the hugepte.
-		 */
-		more = addr + (1UL << hugepd_shift(*(hugepd_t *)pmd));
-		if (more > next)
-			next = more;
-
-		free_hugepd_range(tlb, (hugepd_t *)pmd, PMD_SHIFT,
-				  addr, next, floor, ceiling);
-	} while (addr = next, addr != end);
-
-	if (range_is_outside_limits(start, end, floor, ceiling, PUD_MASK))
-		return;
-
-	pmd = pmd_offset(pud, start & PUD_MASK);
-	pud_clear(pud);
-	pmd_free_tlb(tlb, pmd, start & PUD_MASK);
-	mm_dec_nr_pmds(tlb->mm);
-}
-
-static void hugetlb_free_pud_range(struct mmu_gather *tlb, p4d_t *p4d,
-				   unsigned long addr, unsigned long end,
-				   unsigned long floor, unsigned long ceiling)
-{
-	pud_t *pud;
-	unsigned long next;
-	unsigned long start;
-
-	start = addr;
-	do {
-		pud = pud_offset(p4d, addr);
-		next = pud_addr_end(addr, end);
-		if (!is_hugepd(__hugepd(pud_val(*pud)))) {
-			if (pud_none_or_clear_bad(pud))
-				continue;
-			hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
-					       ceiling);
-		} else {
-			unsigned long more;
-			/*
-			 * Increment next by the size of the huge mapping since
-			 * there may be more than one entry at this level for a
-			 * single hugepage, but all of them point to
-			 * the same kmem cache that holds the hugepte.
-			 */
-			more = addr + (1UL << hugepd_shift(*(hugepd_t *)pud));
-			if (more > next)
-				next = more;
-
-			free_hugepd_range(tlb, (hugepd_t *)pud, PUD_SHIFT,
-					  addr, next, floor, ceiling);
-		}
-	} while (addr = next, addr != end);
-
-	if (range_is_outside_limits(start, end, floor, ceiling, PGDIR_MASK))
-		return;
-
-	pud = pud_offset(p4d, start & PGDIR_MASK);
-	p4d_clear(p4d);
-	pud_free_tlb(tlb, pud, start & PGDIR_MASK);
-	mm_dec_nr_puds(tlb->mm);
-}
-
-/*
- * This function frees user-level page tables of a process.
- */
-void hugetlb_free_pgd_range(struct mmu_gather *tlb,
-			    unsigned long addr, unsigned long end,
-			    unsigned long floor, unsigned long ceiling)
-{
-	pgd_t *pgd;
-	p4d_t *p4d;
-	unsigned long next;
-
-	/*
-	 * Because there are a number of different possible pagetable
-	 * layouts for hugepage ranges, we limit knowledge of how
-	 * things should be laid out to the allocation path
-	 * (huge_pte_alloc(), above).  Everything else works out the
-	 * structure as it goes from information in the hugepd
-	 * pointers.  That means that we can't here use the
-	 * optimization used in the normal page free_pgd_range(), of
-	 * checking whether we're actually covering a large enough
-	 * range to have to do anything at the top level of the walk
-	 * instead of at the bottom.
-	 *
-	 * To make sense of this, you should probably go read the big
-	 * block comment at the top of the normal free_pgd_range(),
-	 * too.
-	 */
-
-	do {
-		next = pgd_addr_end(addr, end);
-		pgd = pgd_offset(tlb->mm, addr);
-		p4d = p4d_offset(pgd, addr);
-		if (!is_hugepd(__hugepd(pgd_val(*pgd)))) {
-			if (p4d_none_or_clear_bad(p4d))
-				continue;
-			hugetlb_free_pud_range(tlb, p4d, addr, next, floor, ceiling);
-		} else {
-			unsigned long more;
-			/*
-			 * Increment next by the size of the huge mapping since
-			 * there may be more than one entry at the pgd level
-			 * for a single hugepage, but all of them point to the
-			 * same kmem cache that holds the hugepte.
-			 */
-			more = addr + (1UL << hugepd_shift(*(hugepd_t *)pgd));
-			if (more > next)
-				next = more;
-
-			free_hugepd_range(tlb, (hugepd_t *)p4d, PGDIR_SHIFT,
-					  addr, next, floor, ceiling);
-		}
-	} while (addr = next, addr != end);
-}
-#endif
-
 bool __init arch_hugetlb_valid_size(unsigned long size)
 {
 	int shift = __ffs(size);
diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c
index d3a7726ecf51..024e95c62a2d 100644
--- a/arch/powerpc/mm/init-common.c
+++ b/arch/powerpc/mm/init-common.c
@@ -120,12 +120,8 @@ void pgtable_cache_add(unsigned int shift)
 	/* When batching pgtable pointers for RCU freeing, we store
 	 * the index size in the low bits.  Table alignment must be
 	 * big enough to fit it.
-	 *
-	 * Likewise, hugeapge pagetable pointers contain a (different)
-	 * shift value in the low bits.  All tables must be aligned so
-	 * as to leave enough 0 bits in the address to contain it. */
-	unsigned long minalign = max(MAX_PGTABLE_INDEX_SIZE + 1,
-				     HUGEPD_SHIFT_MASK + 1);
+	 */
+	unsigned long minalign = MAX_PGTABLE_INDEX_SIZE + 1;
 	struct kmem_cache *new = NULL;
 
 	/* It would be nice if this was a BUILD_BUG_ON(), but at the
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index 218792cb2c47..ab0656115424 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -409,11 +409,10 @@ unsigned long vmalloc_to_phys(void *va)
 EXPORT_SYMBOL_GPL(vmalloc_to_phys);
 
 /*
- * We have 4 cases for pgds and pmds:
+ * We have 3 cases for pgds and pmds:
  * (1) invalid (all zeroes)
  * (2) pointer to next table, as normal; bottom 6 bits == 0
  * (3) leaf pte for huge page _PAGE_PTE set
- * (4) hugepd pointer, _PAGE_PTE = 0 and bits [2..6] indicate size of table
  *
  * So long as we atomically load page table pointers we are safe against teardown,
  * we can follow the address down to the page and take a ref on it.
@@ -430,7 +429,6 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
 #endif
 	pmd_t pmd, *pmdp;
 	pte_t *ret_pte;
-	hugepd_t *hpdp = NULL;
 	unsigned pdshift;
 
 	if (hpage_shift)
@@ -463,11 +461,6 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
 		goto out;
 	}
 
-	if (is_hugepd(__hugepd(p4d_val(p4d)))) {
-		hpdp = (hugepd_t *)&p4d;
-		goto out_huge;
-	}
-
 	/*
 	 * Even if we end up with an unmap, the pgtable will not
 	 * be freed, because we do an rcu free and here we are
@@ -485,11 +478,6 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
 		goto out;
 	}
 
-	if (is_hugepd(__hugepd(pud_val(pud)))) {
-		hpdp = (hugepd_t *)&pud;
-		goto out_huge;
-	}
-
 	pmdp = pmd_offset(&pud, ea);
 #else
 	pmdp = pmd_offset(pud_offset(p4d_offset(pgdp, ea), ea), ea);
@@ -527,21 +515,8 @@ pte_t *__find_linux_pte(pgd_t *pgdir, unsigned long ea,
 		goto out;
 	}
 
-	if (is_hugepd(__hugepd(pmd_val(pmd)))) {
-		hpdp = (hugepd_t *)&pmd;
-		goto out_huge;
-	}
-
 	return pte_offset_kernel(&pmd, ea);
 
-out_huge:
-	if (!hpdp)
-		return NULL;
-
-#ifdef CONFIG_ARCH_HAS_HUGEPD
-	ret_pte = hugepte_offset(*hpdp, ea, pdshift);
-	pdshift = hugepd_shift(*hpdp);
-#endif
 out:
 	if (hpage_shift)
 		*hpage_shift = pdshift;
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* [PATCH v7 23/23] mm: Remove CONFIG_ARCH_HAS_HUGEPD
  2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
                   ` (21 preceding siblings ...)
  2024-07-02 13:51 ` [PATCH v7 22/23] powerpc/mm: Remove hugepd leftovers Christophe Leroy
@ 2024-07-02 13:51 ` Christophe Leroy
  22 siblings, 0 replies; 28+ messages in thread
From: Christophe Leroy @ 2024-07-02 13:51 UTC (permalink / raw)
  To: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin
  Cc: Christophe Leroy, linux-kernel, linux-mm, linuxppc-dev

powerpc was the only user of CONFIG_ARCH_HAS_HUGEPD and doesn't
use it anymore, so remove all related code.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Acked-by: Oscar Salvador <osalvador@suse.de>
---
v4: Rebased on v6.10-rc1

v7: Rebased on mm-unstable (9bb8753acdd8)
---
 include/linux/hugetlb.h |   6 --
 mm/Kconfig              |  10 ---
 mm/gup.c                | 194 ++--------------------------------------
 mm/pagewalk.c           |  57 +-----------
 4 files changed, 9 insertions(+), 258 deletions(-)

diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index a951c0d06061..ecd0ceeea206 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -20,12 +20,6 @@ struct user_struct;
 struct mmu_gather;
 struct node;
 
-#ifndef CONFIG_ARCH_HAS_HUGEPD
-typedef struct { unsigned long pd; } hugepd_t;
-#define is_hugepd(hugepd) (0)
-#define __hugepd(x) ((hugepd_t) { (x) })
-#endif
-
 void free_huge_folio(struct folio *folio);
 
 #ifdef CONFIG_HUGETLB_PAGE
diff --git a/mm/Kconfig b/mm/Kconfig
index 991fa9cf6137..60796402850e 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -1126,16 +1126,6 @@ config DMAPOOL_TEST
 config ARCH_HAS_PTE_SPECIAL
 	bool
 
-#
-# Some architectures require a special hugepage directory format that is
-# required to support multiple hugepage sizes. For example a4fe3ce76
-# "powerpc/mm: Allow more flexible layouts for hugepage pagetables"
-# introduced it on powerpc.  This allows for a more flexible hugepage
-# pagetable layouts.
-#
-config ARCH_HAS_HUGEPD
-	bool
-
 config MAPPING_DIRTY_HELPERS
         bool
 
diff --git a/mm/gup.c b/mm/gup.c
index aaf6ef4e28ee..87581ce6bc45 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -462,7 +462,7 @@ static inline void mm_set_has_pinned_flag(unsigned long *mm_flags)
 
 #ifdef CONFIG_MMU
 
-#if defined(CONFIG_ARCH_HAS_HUGEPD) || defined(CONFIG_HAVE_GUP_FAST)
+#ifdef CONFIG_HAVE_GUP_FAST
 static int record_subpages(struct page *page, unsigned long sz,
 			   unsigned long addr, unsigned long end,
 			   struct page **pages)
@@ -476,154 +476,7 @@ static int record_subpages(struct page *page, unsigned long sz,
 
 	return nr;
 }
-#endif	/* CONFIG_ARCH_HAS_HUGEPD || CONFIG_HAVE_GUP_FAST */
-
-#ifdef CONFIG_ARCH_HAS_HUGEPD
-static unsigned long hugepte_addr_end(unsigned long addr, unsigned long end,
-				      unsigned long sz)
-{
-	unsigned long __boundary = (addr + sz) & ~(sz-1);
-	return (__boundary - 1 < end - 1) ? __boundary : end;
-}
-
-/*
- * Returns 1 if succeeded, 0 if failed, -EMLINK if unshare needed.
- *
- * NOTE: for the same entry, gup-fast and gup-slow can return different
- * results (0 v.s. -EMLINK) depending on whether vma is available.  This is
- * the expected behavior, where we simply want gup-fast to fallback to
- * gup-slow to take the vma reference first.
- */
-static int gup_hugepte(struct vm_area_struct *vma, pte_t *ptep, unsigned long sz,
-		       unsigned long addr, unsigned long end, unsigned int flags,
-		       struct page **pages, int *nr, bool fast)
-{
-	unsigned long pte_end;
-	struct page *page;
-	struct folio *folio;
-	pte_t pte;
-	int refs;
-
-	pte_end = (addr + sz) & ~(sz-1);
-	if (pte_end < end)
-		end = pte_end;
-
-	pte = huge_ptep_get(vma->vm_mm, addr, ptep);
-
-	if (!pte_access_permitted(pte, flags & FOLL_WRITE))
-		return 0;
-
-	/* hugepages are never "special" */
-	VM_BUG_ON(!pfn_valid(pte_pfn(pte)));
-
-	page = pte_page(pte);
-	refs = record_subpages(page, sz, addr, end, pages + *nr);
-
-	if (fast) {
-		folio = try_grab_folio_fast(page, refs, flags);
-		if (!folio)
-			return 0;
-	} else {
-		folio = page_folio(page);
-		if (try_grab_folio(folio, refs, flags))
-			return 0;
-	}
-
-	if (unlikely(pte_val(pte) != pte_val(ptep_get(ptep)))) {
-		gup_put_folio(folio, refs, flags);
-		return 0;
-	}
-
-	if (!pte_write(pte) && gup_must_unshare(vma, flags, &folio->page)) {
-		gup_put_folio(folio, refs, flags);
-		return -EMLINK;
-	}
-
-	*nr += refs;
-	folio_set_referenced(folio);
-	return 1;
-}
-
-/*
- * NOTE: currently GUP for a hugepd is only possible on hugetlbfs file
- * systems on Power, which does not have issue with folio writeback against
- * GUP updates.  When hugepd will be extended to support non-hugetlbfs or
- * even anonymous memory, we need to do extra check as what we do with most
- * of the other folios. See writable_file_mapping_allowed() and
- * gup_fast_folio_allowed() for more information.
- */
-static int gup_hugepd(struct vm_area_struct *vma, hugepd_t hugepd,
-		      unsigned long addr, unsigned int pdshift,
-		      unsigned long end, unsigned int flags,
-		      struct page **pages, int *nr, bool fast)
-{
-	pte_t *ptep;
-	unsigned long sz = 1UL << hugepd_shift(hugepd);
-	unsigned long next;
-	int ret;
-
-	ptep = hugepte_offset(hugepd, addr, pdshift);
-	do {
-		next = hugepte_addr_end(addr, end, sz);
-		ret = gup_hugepte(vma, ptep, sz, addr, end, flags, pages, nr,
-				  fast);
-		if (ret != 1)
-			return ret;
-	} while (ptep++, addr = next, addr != end);
-
-	return 1;
-}
-
-static struct page *follow_hugepd(struct vm_area_struct *vma, hugepd_t hugepd,
-				  unsigned long addr, unsigned int pdshift,
-				  unsigned int flags,
-				  struct follow_page_context *ctx)
-{
-	struct page *page;
-	struct hstate *h;
-	spinlock_t *ptl;
-	int nr = 0, ret;
-	pte_t *ptep;
-
-	/* Only hugetlb supports hugepd */
-	if (WARN_ON_ONCE(!is_vm_hugetlb_page(vma)))
-		return ERR_PTR(-EFAULT);
-
-	h = hstate_vma(vma);
-	ptep = hugepte_offset(hugepd, addr, pdshift);
-	ptl = huge_pte_lock(h, vma->vm_mm, ptep);
-	ret = gup_hugepd(vma, hugepd, addr, pdshift, addr + PAGE_SIZE,
-			 flags, &page, &nr, false);
-	spin_unlock(ptl);
-
-	if (ret == 1) {
-		/* GUP succeeded */
-		WARN_ON_ONCE(nr != 1);
-		ctx->page_mask = (1U << huge_page_order(h)) - 1;
-		return page;
-	}
-
-	/* ret can be either 0 (translates to NULL) or negative */
-	return ERR_PTR(ret);
-}
-#else /* CONFIG_ARCH_HAS_HUGEPD */
-static inline int gup_hugepd(struct vm_area_struct *vma, hugepd_t hugepd,
-			     unsigned long addr, unsigned int pdshift,
-			     unsigned long end, unsigned int flags,
-			     struct page **pages, int *nr, bool fast)
-{
-	return 0;
-}
-
-static struct page *follow_hugepd(struct vm_area_struct *vma, hugepd_t hugepd,
-				  unsigned long addr, unsigned int pdshift,
-				  unsigned int flags,
-				  struct follow_page_context *ctx)
-{
-	return NULL;
-}
-#endif /* CONFIG_ARCH_HAS_HUGEPD */
-
+#endif	/* CONFIG_HAVE_GUP_FAST */
 
 static struct page *no_page_table(struct vm_area_struct *vma,
 				  unsigned int flags, unsigned long address)
@@ -993,9 +846,6 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma,
 		return no_page_table(vma, flags, address);
 	if (!pmd_present(pmdval))
 		return no_page_table(vma, flags, address);
-	if (unlikely(is_hugepd(__hugepd(pmd_val(pmdval)))))
-		return follow_hugepd(vma, __hugepd(pmd_val(pmdval)),
-				     address, PMD_SHIFT, flags, ctx);
 	if (pmd_devmap(pmdval)) {
 		ptl = pmd_lock(mm, pmd);
 		page = follow_devmap_pmd(vma, address, pmd, flags, &ctx->pgmap);
@@ -1046,9 +896,6 @@ static struct page *follow_pud_mask(struct vm_area_struct *vma,
 	pud = READ_ONCE(*pudp);
 	if (!pud_present(pud))
 		return no_page_table(vma, flags, address);
-	if (unlikely(is_hugepd(__hugepd(pud_val(pud)))))
-		return follow_hugepd(vma, __hugepd(pud_val(pud)),
-				     address, PUD_SHIFT, flags, ctx);
 	if (pud_leaf(pud)) {
 		ptl = pud_lock(mm, pudp);
 		page = follow_huge_pud(vma, address, pudp, flags, ctx);
@@ -1074,10 +921,6 @@ static struct page *follow_p4d_mask(struct vm_area_struct *vma,
 	p4d = READ_ONCE(*p4dp);
 	BUILD_BUG_ON(p4d_leaf(p4d));
 
-	if (unlikely(is_hugepd(__hugepd(p4d_val(p4d)))))
-		return follow_hugepd(vma, __hugepd(p4d_val(p4d)),
-				     address, P4D_SHIFT, flags, ctx);
-
 	if (!p4d_present(p4d) || p4d_bad(p4d))
 		return no_page_table(vma, flags, address);
 
@@ -1121,10 +964,7 @@ static struct page *follow_page_mask(struct vm_area_struct *vma,
 	ctx->page_mask = 0;
 	pgd = pgd_offset(mm, address);
 
-	if (unlikely(is_hugepd(__hugepd(pgd_val(*pgd)))))
-		page = follow_hugepd(vma, __hugepd(pgd_val(*pgd)),
-				     address, PGDIR_SHIFT, flags, ctx);
-	else if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
+	if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd)))
 		page = no_page_table(vma, flags, address);
 	else
 		page = follow_p4d_mask(vma, address, pgd, flags, ctx);
@@ -3362,15 +3202,6 @@ static int gup_fast_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr,
 				pages, nr))
 				return 0;
 
-		} else if (unlikely(is_hugepd(__hugepd(pmd_val(pmd))))) {
-			/*
-			 * architecture have different format for hugetlbfs
-			 * pmd format and THP pmd format
-			 */
-			if (gup_hugepd(NULL, __hugepd(pmd_val(pmd)), addr,
-				       PMD_SHIFT, next, flags, pages, nr,
-				       true) != 1)
-				return 0;
 		} else if (!gup_fast_pte_range(pmd, pmdp, addr, next, flags,
 					       pages, nr))
 			return 0;
@@ -3397,11 +3228,6 @@ static int gup_fast_pud_range(p4d_t *p4dp, p4d_t p4d, unsigned long addr,
 			if (!gup_fast_pud_leaf(pud, pudp, addr, next, flags,
 					       pages, nr))
 				return 0;
-		} else if (unlikely(is_hugepd(__hugepd(pud_val(pud))))) {
-			if (gup_hugepd(NULL, __hugepd(pud_val(pud)), addr,
-				       PUD_SHIFT, next, flags, pages, nr,
-				       true) != 1)
-				return 0;
 		} else if (!gup_fast_pmd_range(pudp, pud, addr, next, flags,
 					       pages, nr))
 			return 0;
@@ -3425,13 +3251,8 @@ static int gup_fast_p4d_range(pgd_t *pgdp, pgd_t pgd, unsigned long addr,
 		if (!p4d_present(p4d))
 			return 0;
 		BUILD_BUG_ON(p4d_leaf(p4d));
-		if (unlikely(is_hugepd(__hugepd(p4d_val(p4d))))) {
-			if (gup_hugepd(NULL, __hugepd(p4d_val(p4d)), addr,
-				       P4D_SHIFT, next, flags, pages, nr,
-				       true) != 1)
-				return 0;
-		} else if (!gup_fast_pud_range(p4dp, p4d, addr, next, flags,
-					       pages, nr))
+		if (!gup_fast_pud_range(p4dp, p4d, addr, next, flags,
+					pages, nr))
 			return 0;
 	} while (p4dp++, addr = next, addr != end);
 
@@ -3455,11 +3276,6 @@ static void gup_fast_pgd_range(unsigned long addr, unsigned long end,
 			if (!gup_fast_pgd_leaf(pgd, pgdp, addr, next, flags,
 					       pages, nr))
 				return;
-		} else if (unlikely(is_hugepd(__hugepd(pgd_val(pgd))))) {
-			if (gup_hugepd(NULL, __hugepd(pgd_val(pgd)), addr,
-				       PGDIR_SHIFT, next, flags, pages, nr,
-				       true) != 1)
-				return;
 		} else if (!gup_fast_p4d_range(pgdp, pgd, addr, next, flags,
 					       pages, nr))
 			return;
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index f46c80b18ce4..ae2f08ce991b 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -73,45 +73,6 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 	return err;
 }
 
-#ifdef CONFIG_ARCH_HAS_HUGEPD
-static int walk_hugepd_range(hugepd_t *phpd, unsigned long addr,
-			     unsigned long end, struct mm_walk *walk, int pdshift)
-{
-	int err = 0;
-	const struct mm_walk_ops *ops = walk->ops;
-	int shift = hugepd_shift(*phpd);
-	int page_size = 1 << shift;
-
-	if (!ops->pte_entry)
-		return 0;
-
-	if (addr & (page_size - 1))
-		return 0;
-
-	for (;;) {
-		pte_t *pte;
-
-		spin_lock(&walk->mm->page_table_lock);
-		pte = hugepte_offset(*phpd, addr, pdshift);
-		err = ops->pte_entry(pte, addr, addr + page_size, walk);
-		spin_unlock(&walk->mm->page_table_lock);
-
-		if (err)
-			break;
-		if (addr >= end - page_size)
-			break;
-		addr += page_size;
-	}
-	return err;
-}
-#else
-static int walk_hugepd_range(hugepd_t *phpd, unsigned long addr,
-			     unsigned long end, struct mm_walk *walk, int pdshift)
-{
-	return 0;
-}
-#endif
-
 static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
 			  struct mm_walk *walk)
 {
@@ -159,10 +120,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
 		if (walk->vma)
 			split_huge_pmd(walk->vma, pmd, addr);
 
-		if (is_hugepd(__hugepd(pmd_val(*pmd))))
-			err = walk_hugepd_range((hugepd_t *)pmd, addr, next, walk, PMD_SHIFT);
-		else
-			err = walk_pte_range(pmd, addr, next, walk);
+		err = walk_pte_range(pmd, addr, next, walk);
 		if (err)
 			break;
 
@@ -215,10 +173,7 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
 		if (pud_none(*pud))
 			goto again;
 
-		if (is_hugepd(__hugepd(pud_val(*pud))))
-			err = walk_hugepd_range((hugepd_t *)pud, addr, next, walk, PUD_SHIFT);
-		else
-			err = walk_pmd_range(pud, addr, next, walk);
+		err = walk_pmd_range(pud, addr, next, walk);
 		if (err)
 			break;
 	} while (pud++, addr = next, addr != end);
@@ -250,9 +205,7 @@ static int walk_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
 			if (err)
 				break;
 		}
-		if (is_hugepd(__hugepd(p4d_val(*p4d))))
-			err = walk_hugepd_range((hugepd_t *)p4d, addr, next, walk, P4D_SHIFT);
-		else if (ops->pud_entry || ops->pmd_entry || ops->pte_entry)
+		if (ops->pud_entry || ops->pmd_entry || ops->pte_entry)
 			err = walk_pud_range(p4d, addr, next, walk);
 		if (err)
 			break;
@@ -287,9 +240,7 @@ static int walk_pgd_range(unsigned long addr, unsigned long end,
 			if (err)
 				break;
 		}
-		if (is_hugepd(__hugepd(pgd_val(*pgd))))
-			err = walk_hugepd_range((hugepd_t *)pgd, addr, next, walk, PGDIR_SHIFT);
-		else if (ops->p4d_entry || ops->pud_entry || ops->pmd_entry || ops->pte_entry)
+		if (ops->p4d_entry || ops->pud_entry || ops->pmd_entry || ops->pte_entry)
 			err = walk_p4d_range(pgd, addr, next, walk);
 		if (err)
 			break;
-- 
2.44.0



^ permalink raw reply related	[flat|nested] 28+ messages in thread

* Re: [PATCH v7 16/23] powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits)
  2024-07-02 13:51 ` [PATCH v7 16/23] powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits) Christophe Leroy
@ 2024-07-29 22:10   ` Guenter Roeck
  2024-07-31 15:36     ` LEROY Christophe
  0 siblings, 1 reply; 28+ messages in thread
From: Guenter Roeck @ 2024-07-29 22:10 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: Andrew Morton, Jason Gunthorpe, Peter Xu, Oscar Salvador,
	Michael Ellerman, Nicholas Piggin, linux-kernel, linux-mm,
	linuxppc-dev

Hi,

On Tue, Jul 02, 2024 at 03:51:28PM +0200, Christophe Leroy wrote:
> At the time being when CONFIG_PTE_64BIT is selected, PTE entries are
> 64 bits but PGD entries are still 32 bits.
> 
> In order to allow leaf PMD entries, switch the PGD to 64 bits entries.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

With this patch in the mainline kernel, all my boot tests based on the
mpc8544ds qemu emulation start crashing. Example crash log:

kernel BUG at include/linux/pgtable.h:1599!
Oops: Exception in kernel mode, sig: 5 [#1]
BE PAGE_SIZE=4K MPC8544 DS
Modules linked in:
CPU: 0 UID: 0 PID: 1 Comm: swapper Tainted: G                 N 6.11.0-rc1 #1
Tainted: [N]=TEST
Hardware name: MPC8544DS e500v2 0x80210030 MPC8544 DS
NIP:  c01f51b8 LR: c01f6fec CTR: 00000000
REGS: c4135c40 TRAP: 0700   Tainted: G                 N  (6.11.0-rc1)
MSR:  00029000 <CE,EE,ME>  CR: 24228288  XER: 20000000
GPR00: c01f6fc0 c4135d30 c415bf20 c762e3f0 c29c9318 c7624ff8 0000026b b5fc2ea1
GPR08: 00000000 00000000 5a5a5000 b7f4dd55 44228282 00000000 c0005014 00000000
GPR16: 00000000 00000000 00000001 00050003 24228282 24228282 00000000 00000095
GPR24: c1375b30 c4135de8 c4135e48 00050003 c762e3a0 c762e3f0 bffffff1 c7676a08
NIP [c01f51b8] pmd_write.constprop.0.isra.0+0x4/0x8
LR [c01f6fec] follow_page_mask+0x150/0x17c
Call Trace:
[c4135d30] [c4135de8] 0xc4135de8 (unreliable)
[c4135d40] [c01f6fc0] follow_page_mask+0x124/0x17c
[c4135d70] [c01f7170] __get_user_pages+0x158/0x5d8
[c4135dd0] [c01f7750] get_user_pages_remote+0x160/0x560
[c4135e30] [c026838c] get_arg_page+0xb0/0x25c
[c4135e70] [c0268dd4] copy_string_kernel+0xf0/0x200
[c4135eb0] [c026a0e4] kernel_execve+0xbc/0x190
[c4135ee0] [c0005108] kernel_init+0xf4/0x1d4
[c4135f00] [c0016224] ret_from_kernel_user_thread+0x10/0x18

This is with v6.11-rc1; the actually observed crash differs from test
to test while running bisect.

I can't just revert the patch because subsequent patches depend on it.
Is this confirmed to work on real hardware ? If so, do you have a
suggestion how I could continue to use the mpc8544ds emulation for
testing, or is it just dead ?

For reference, the configuration file is mpc85xx_defconfig.
Bisect log is attached.

Thanks,
Guenter

---
# bad: [8400291e289ee6b2bf9779ff1c83a291501f017b] Linux 6.11-rc1
# good: [2c9b3512402ed192d1f43f4531fb5da947e72bd0] Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
git bisect start 'v6.11-rc1' '2c9b3512402e'
# bad: [6dc2e98d5f1de162d1777aee97e59d75d70d07c5] s390: Remove protvirt and kvm config guards for uv code
git bisect bad 6dc2e98d5f1de162d1777aee97e59d75d70d07c5
# bad: [30d77b7eef019fa4422980806e8b7cdc8674493e] mm/mglru: fix ineffective protection calculation
git bisect bad 30d77b7eef019fa4422980806e8b7cdc8674493e
# good: [c02525a33969000fa7b595b743deb4d79804916b] ftrace: unpoison ftrace_regs in ftrace_ops_list_func()
git bisect good c02525a33969000fa7b595b743deb4d79804916b
# good: [8ef6fd0e9ea83a792ba53882ddc6e0d38ce0d636] Merge branch 'mm-hotfixes-stable' into mm-stable to pick up "mm: fix crashes from deferred split racing folio migration", needed by "mm: migrate: split folio_migrate_mapping()".
git bisect good 8ef6fd0e9ea83a792ba53882ddc6e0d38ce0d636
# good: [a898530eea3d0ba08c17a60865995a3bb468d1bc] powerpc/64e: split out nohash Book3E 64-bit code
git bisect good a898530eea3d0ba08c17a60865995a3bb468d1bc
# bad: [00f58104202c472e487f0866fbd38832523fd4f9] mm: fix khugepaged activation policy
git bisect bad 00f58104202c472e487f0866fbd38832523fd4f9
# good: [e081c14744f4a93514069e1af1a7273d5451b909] powerpc/e500: remove enc and ind fields from struct mmu_psize_def
git bisect good e081c14744f4a93514069e1af1a7273d5451b909
# bad: [57fb15c32f4f6a4f1a58f1fbc58a799c3f975ed8] powerpc/64s: use contiguous PMD/PUD instead of HUGEPD
git bisect bad 57fb15c32f4f6a4f1a58f1fbc58a799c3f975ed8
# bad: [276d5affbbaea4d369d1e5b9711cb2951037f6ee] powerpc/e500: don't pre-check write access on data TLB error
git bisect bad 276d5affbbaea4d369d1e5b9711cb2951037f6ee
# bad: [84319905ca5f3759c42082e20ed978c81f4dead0] powerpc/e500: encode hugepage size in PTE bits
git bisect bad 84319905ca5f3759c42082e20ed978c81f4dead0
# bad: [6b0e82791bd03b2326c7f7d8c1124c825742f2a4] powerpc/e500: switch to 64 bits PGD on 85xx (32 bits)
git bisect bad 6b0e82791bd03b2326c7f7d8c1124c825742f2a4
# first bad commit: [6b0e82791bd03b2326c7f7d8c1124c825742f2a4] powerpc/e500: switch to 64 bits PGD on 85xx (32 bits)


^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [PATCH v7 16/23] powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits)
  2024-07-29 22:10   ` Guenter Roeck
@ 2024-07-31 15:36     ` LEROY Christophe
  2024-07-31 16:35       ` Guenter Roeck
  0 siblings, 1 reply; 28+ messages in thread
From: LEROY Christophe @ 2024-07-31 15:36 UTC (permalink / raw)
  To: Guenter Roeck, LEROY Christophe
  Cc: linux-kernel@vger.kernel.org, Nicholas Piggin, linux-mm@kvack.org,
	Peter Xu, Jason Gunthorpe, Andrew Morton,
	linuxppc-dev@lists.ozlabs.org, Oscar Salvador

[-- Attachment #1: Type: text/plain, Size: 5757 bytes --]


Hi Guenter,
Thanks for this report. I'm afk this week, i"ll have a look at it in more détails next week.
But to be sûre, does that Oops match the bisected commit ? Because pmd_leaf()  for e500 doesn't exist yet so pmd_write() shouldnt be called.
I did validate all my changes with mpc8544 on qemu when i implemented this séries, using map_hugetlb mm selftest. What test tool are you using ?
Thanks
Christophe

Envoyé à partir de Outlook pour Android<https://aka.ms/AAb9ysg>
________________________________
From: Linuxppc-dev <linuxppc-dev-bounces+christophe.leroy2=cs-soprasteria.com@lists.ozlabs.org> on behalf of Guenter Roeck <linux@roeck-us.net>
Sent: Tuesday, July 30, 2024 12:10:51 AM
To: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>; Nicholas Piggin <npiggin@gmail.com>; linux-mm@kvack.org <linux-mm@kvack.org>; Peter Xu <peterx@redhat.com>; Jason Gunthorpe <jgg@nvidia.com>; Andrew Morton <akpm@linux-foundation.org>; linuxppc-dev@lists.ozlabs.org <linuxppc-dev@lists.ozlabs.org>; Oscar Salvador <osalvador@suse.de>
Subject: Re: [PATCH v7 16/23] powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits)

Hi,

On Tue, Jul 02, 2024 at 03:51:28PM +0200, Christophe Leroy wrote:
> At the time being when CONFIG_PTE_64BIT is selected, PTE entries are
> 64 bits but PGD entries are still 32 bits.
>
> In order to allow leaf PMD entries, switch the PGD to 64 bits entries.
>
> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

With this patch in the mainline kernel, all my boot tests based on the
mpc8544ds qemu emulation start crashing. Example crash log:

kernel BUG at include/linux/pgtable.h:1599!
Oops: Exception in kernel mode, sig: 5 [#1]
BE PAGE_SIZE=4K MPC8544 DS
Modules linked in:
CPU: 0 UID: 0 PID: 1 Comm: swapper Tainted: G                 N 6.11.0-rc1 #1
Tainted: [N]=TEST
Hardware name: MPC8544DS e500v2 0x80210030 MPC8544 DS
NIP:  c01f51b8 LR: c01f6fec CTR: 00000000
REGS: c4135c40 TRAP: 0700   Tainted: G                 N  (6.11.0-rc1)
MSR:  00029000 <CE,EE,ME>  CR: 24228288  XER: 20000000
GPR00: c01f6fc0 c4135d30 c415bf20 c762e3f0 c29c9318 c7624ff8 0000026b b5fc2ea1
GPR08: 00000000 00000000 5a5a5000 b7f4dd55 44228282 00000000 c0005014 00000000
GPR16: 00000000 00000000 00000001 00050003 24228282 24228282 00000000 00000095
GPR24: c1375b30 c4135de8 c4135e48 00050003 c762e3a0 c762e3f0 bffffff1 c7676a08
NIP [c01f51b8] pmd_write.constprop.0.isra.0+0x4/0x8
LR [c01f6fec] follow_page_mask+0x150/0x17c
Call Trace:
[c4135d30] [c4135de8] 0xc4135de8 (unreliable)
[c4135d40] [c01f6fc0] follow_page_mask+0x124/0x17c
[c4135d70] [c01f7170] __get_user_pages+0x158/0x5d8
[c4135dd0] [c01f7750] get_user_pages_remote+0x160/0x560
[c4135e30] [c026838c] get_arg_page+0xb0/0x25c
[c4135e70] [c0268dd4] copy_string_kernel+0xf0/0x200
[c4135eb0] [c026a0e4] kernel_execve+0xbc/0x190
[c4135ee0] [c0005108] kernel_init+0xf4/0x1d4
[c4135f00] [c0016224] ret_from_kernel_user_thread+0x10/0x18

This is with v6.11-rc1; the actually observed crash differs from test
to test while running bisect.

I can't just revert the patch because subsequent patches depend on it.
Is this confirmed to work on real hardware ? If so, do you have a
suggestion how I could continue to use the mpc8544ds emulation for
testing, or is it just dead ?

For reference, the configuration file is mpc85xx_defconfig.
Bisect log is attached.

Thanks,
Guenter

---
# bad: [8400291e289ee6b2bf9779ff1c83a291501f017b] Linux 6.11-rc1
# good: [2c9b3512402ed192d1f43f4531fb5da947e72bd0] Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
git bisect start 'v6.11-rc1' '2c9b3512402e'
# bad: [6dc2e98d5f1de162d1777aee97e59d75d70d07c5] s390: Remove protvirt and kvm config guards for uv code
git bisect bad 6dc2e98d5f1de162d1777aee97e59d75d70d07c5
# bad: [30d77b7eef019fa4422980806e8b7cdc8674493e] mm/mglru: fix ineffective protection calculation
git bisect bad 30d77b7eef019fa4422980806e8b7cdc8674493e
# good: [c02525a33969000fa7b595b743deb4d79804916b] ftrace: unpoison ftrace_regs in ftrace_ops_list_func()
git bisect good c02525a33969000fa7b595b743deb4d79804916b
# good: [8ef6fd0e9ea83a792ba53882ddc6e0d38ce0d636] Merge branch 'mm-hotfixes-stable' into mm-stable to pick up "mm: fix crashes from deferred split racing folio migration", needed by "mm: migrate: split folio_migrate_mapping()".
git bisect good 8ef6fd0e9ea83a792ba53882ddc6e0d38ce0d636
# good: [a898530eea3d0ba08c17a60865995a3bb468d1bc] powerpc/64e: split out nohash Book3E 64-bit code
git bisect good a898530eea3d0ba08c17a60865995a3bb468d1bc
# bad: [00f58104202c472e487f0866fbd38832523fd4f9] mm: fix khugepaged activation policy
git bisect bad 00f58104202c472e487f0866fbd38832523fd4f9
# good: [e081c14744f4a93514069e1af1a7273d5451b909] powerpc/e500: remove enc and ind fields from struct mmu_psize_def
git bisect good e081c14744f4a93514069e1af1a7273d5451b909
# bad: [57fb15c32f4f6a4f1a58f1fbc58a799c3f975ed8] powerpc/64s: use contiguous PMD/PUD instead of HUGEPD
git bisect bad 57fb15c32f4f6a4f1a58f1fbc58a799c3f975ed8
# bad: [276d5affbbaea4d369d1e5b9711cb2951037f6ee] powerpc/e500: don't pre-check write access on data TLB error
git bisect bad 276d5affbbaea4d369d1e5b9711cb2951037f6ee
# bad: [84319905ca5f3759c42082e20ed978c81f4dead0] powerpc/e500: encode hugepage size in PTE bits
git bisect bad 84319905ca5f3759c42082e20ed978c81f4dead0
# bad: [6b0e82791bd03b2326c7f7d8c1124c825742f2a4] powerpc/e500: switch to 64 bits PGD on 85xx (32 bits)
git bisect bad 6b0e82791bd03b2326c7f7d8c1124c825742f2a4
# first bad commit: [6b0e82791bd03b2326c7f7d8c1124c825742f2a4] powerpc/e500: switch to 64 bits PGD on 85xx (32 bits)


C2 - Usage restreint

[-- Attachment #2: Type: text/html, Size: 7431 bytes --]

^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [PATCH v7 16/23] powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits)
  2024-07-31 15:36     ` LEROY Christophe
@ 2024-07-31 16:35       ` Guenter Roeck
       [not found]         ` <b73e991e-5f66-455e-a271-e10511ebeaef@csgroup.eu>
  0 siblings, 1 reply; 28+ messages in thread
From: Guenter Roeck @ 2024-07-31 16:35 UTC (permalink / raw)
  To: LEROY Christophe, LEROY Christophe
  Cc: linux-kernel@vger.kernel.org, Nicholas Piggin, linux-mm@kvack.org,
	Peter Xu, Jason Gunthorpe, Andrew Morton,
	linuxppc-dev@lists.ozlabs.org, Oscar Salvador

On 7/31/24 08:36, LEROY Christophe wrote:
> 
> Hi Guenter,
> Thanks for this report. I'm afk this week, i"ll have a look at it in more détails next week.
> But to be sûre, does that Oops match the bisected commit ? Because pmd_leaf()  for e500 doesn't exist yet so pmd_write() shouldnt be called.
> I did validate all my changes with mpc8544 on qemu when i implemented this séries, using map_hugetlb mm selftest. What test tool are you using ?

Nothing special; it is just a qemu boot test with various module test and debug options enabled,
using a root file system generated with buildroot.

As mentioned, I can not just revert the offending commit, and the crash signature changes while
running bisect. If I run a test on v6.10-rc6-396-g6b0e82791bd0, I get the following.

...
Btrfs loaded, zoned=no, fsverity=no
------------[ cut here ]------------
WARNING: CPU: 0 PID: 61 at mm/gup.c:685 follow_hugepd.constprop.0+0x138/0x170
Modules linked in:
CPU: 0 PID: 61 Comm: kworker/u4:1 Not tainted 6.10.0-rc6-00396-g6b0e82791bd0 #1
Hardware name: MPC8544DS e500v2 0x80210030 MPC8544 DS
NIP:  c01f5af8 LR: c01f60f4 CTR: 00000000
REGS: c7147be0 TRAP: 0700   Not tainted  (6.10.0-rc6-00396-g6b0e82791bd0)
MSR:  00029000 <CE,EE,ME>  CR: 28228202  XER: 20000000
GPR00: c01f66b8 c7147cd0 c5c08020 c5f2fb88 c7147d1c bfffffed 00050003 c7147d74
GPR08: 00000001 00000000 00000000 ffffffff 28228202 00000000 c0071dcc c5c98968
GPR16: 00000000 00000000 00000001 00050003 28228202 28228202 00000000 00000095
GPR24: c135ce70 c7147dd8 c7147e38 5a5a5a5a 00050003 bfffffed c7147d74 c5f2fb88
NIP [c01f5af8] follow_hugepd.constprop.0+0x138/0x170
LR [c01f60f4] follow_page_mask+0xac/0x518
Call Trace:
[c7147d10] [c02097a4] find_vma+0x44/0x8c
[c7147d60] [c01f66b8] __get_user_pages+0x158/0x5d8
[c7147dc0] [c01f6c98] get_user_pages_remote+0x160/0x560
[c7147e20] [c0266e94] get_arg_page+0xb0/0x25c
[c7147e60] [c02679b8] copy_string_kernel+0xf0/0x200
[c7147ea0] [c0268dbc] kernel_execve+0xfc/0x1dc
[c7147ed0] [c0071ed8] call_usermodehelper_exec_async+0x10c/0x198
[c7147f00] [c0016224] ret_from_kernel_user_thread+0x10/0x18
--- interrupt: 0 at 0x0
Code: 0fe00000 4bffff6c 81210018 2c090001 4082002c 81590050 39200001 80610014 7d295030 3929ffff 913a0004 4bffff94 <0fe00000> 3860fff2 4bffffa8 0fe00000
irq event stamp: 78
hardirqs last  enabled at (77): [<c10391e4>] _raw_spin_unlock_irqrestore+0x70/0xa8
hardirqs last disabled at (78): [<c000ed0c>] program_check_exception+0x78/0x12c
softirqs last  enabled at (0): [<c005047c>] copy_process+0x7dc/0x1e70
softirqs last disabled at (0): [<00000000>] 0x0
---[ end trace 0000000000000000 ]---
mm/pgtable-generic.c:54: bad pgd 5a5a5a5a.
=============================================================================
BUG pgtable-2^11 (Tainted: G        W         ): Object padding overwritten
-----------------------------------------------------------------------------
0xc5fdcff8-0xc5fdcfff @offset=20472. First byte 0x0 instead of 0x5a
Allocated in mm_init.constprop.0+0x260/0x2b4 age=2 cpu=0 pid=61
  mm_init.constprop.0+0x260/0x2b4
  alloc_bprm+0xd0/0x38c
  kernel_execve+0x58/0x1dc
  call_usermodehelper_exec_async+0x10c/0x198
  ret_from_kernel_user_thread+0x10/0x18
Slab 0xcfeb1b00 objects=1 used=1 fp=0x00000000 flags=0x40(head|zone=0)
Object 0xc5fda000 @offset=8192 fp=0x00000000
Redzone  c5fd8000: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................
...
Padding  c5fddff0: 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a 5a  ZZZZZZZZZZZZZZZZ
CPU: 0 PID: 61 Comm: kworker/u4:1 Tainted: G        W          6.10.0-rc6-00396-g6b0e82791bd0 #1
Hardware name: MPC8544DS e500v2 0x80210030 MPC8544 DS
Call Trace:
[c7147d60] [c0ff7a5c] dump_stack_lvl+0x4c/0xc8 (unreliable)
[c7147d80] [c02336b4] check_bytes_and_report+0x17c/0x200
[c7147dc0] [c02318b8] check_object+0x108/0x418
[c7147df0] [c0231ddc] free_to_partial_list+0x214/0x764
[c7147e50] [c004e258] __mmdrop+0x6c/0x140
[c7147e80] [c0267070] free_bprm+0x30/0xbc
[c7147ea0] [c0268e10] kernel_execve+0x150/0x1dc
[c7147ed0] [c0071ed8] call_usermodehelper_exec_async+0x10c/0x198
[c7147f00] [c0016224] ret_from_kernel_user_thread+0x10/0x18
--- interrupt: 0 at 0x0
Disabling lock debugging due to kernel taint
FIX pgtable-2^11: Restoring Object padding 0xc5fdcff8-0xc5fdcfff=0x5a
mm/pgtable-generic.c:54: bad pgd 5a5a5a5a.
=============================================================================
BUG pgtable-2^11 (Tainted: G    B   W         ): Object padding overwritten
-----------------------------------------------------------------------------
0xc5fdcff8-0xc5fdcfff @offset=20472. First byte 0x0 instead of 0x5a
Allocated in mm_init.constprop.0+0x260/0x2b4 age=0 cpu=0 pid=62
  mm_init.constprop.0+0x260/0x2b4
  alloc_bprm+0xd0/0x38c
  kernel_execve+0x58/0x1dc
  call_usermodehelper_exec_async+0x10c/0x198
  ret_from_kernel_user_thread+0x10/0x18
Freed in __mmdrop+0x6c/0x140 age=46 cpu=0 pid=61
  free_bprm+0x30/0xbc
  kernel_execve+0x150/0x1dc
  call_usermodehelper_exec_async+0x10c/0x198
  ret_from_kernel_user_thread+0x10/0x18
Slab 0xcfeb1b00 objects=1 used=1 fp=0x00000000 flags=0x40(head|zone=0)
Object 0xc5fda000 @offset=8192 fp=0x00000000
Redzone  c5fd8000: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc  ................

and so on. The same boot test passes with v6.10-rc6-395-ge081c14744f4.

Context:

Build reference: v6.10-rc6-396-g6b0e82791bd0
Compiler version: powerpc64-linux-gcc (GCC) 11.5.0
Qemu version: 6.2.0 (Debian 1:6.2+dfsg-2ubuntu6.21)

I also tried with qemu 9.0.2 and gcc 13.3, with the same result.

Build reference: v6.10-rc6-396-g6b0e82791bd0
Compiler version: powerpc64-linux-gcc (GCC) 13.3.0
Qemu version: 9.0.2 (v9.0.2-34-gc332443796-dirty)

Guenter

> Thanks
> Christophe
> 
> Envoyé à partir de Outlook pour Android <https://aka.ms/AAb9ysg>
> ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
> *From:* Linuxppc-dev <linuxppc-dev-bounces+christophe.leroy2=cs-soprasteria.com@lists.ozlabs.org> on behalf of Guenter Roeck <linux@roeck-us.net>
> *Sent:* Tuesday, July 30, 2024 12:10:51 AM
> *To:* Christophe Leroy <christophe.leroy@csgroup.eu>
> *Cc:* linux-kernel@vger.kernel.org <linux-kernel@vger.kernel.org>; Nicholas Piggin <npiggin@gmail.com>; linux-mm@kvack.org <linux-mm@kvack.org>; Peter Xu <peterx@redhat.com>; Jason Gunthorpe <jgg@nvidia.com>; Andrew Morton <akpm@linux-foundation.org>; linuxppc-dev@lists.ozlabs.org <linuxppc-dev@lists.ozlabs.org>; Oscar Salvador <osalvador@suse.de>
> *Subject:* Re: [PATCH v7 16/23] powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits)
> Hi,
> 
> On Tue, Jul 02, 2024 at 03:51:28PM +0200, Christophe Leroy wrote:
>> At the time being when CONFIG_PTE_64BIT is selected, PTE entries are
>> 64 bits but PGD entries are still 32 bits.
>> 
>> In order to allow leaf PMD entries, switch the PGD to 64 bits entries.
>> 
>> Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
> 
> With this patch in the mainline kernel, all my boot tests based on the
> mpc8544ds qemu emulation start crashing. Example crash log:
> 
> kernel BUG at include/linux/pgtable.h:1599!
> Oops: Exception in kernel mode, sig: 5 [#1]
> BE PAGE_SIZE=4K MPC8544 DS
> Modules linked in:
> CPU: 0 UID: 0 PID: 1 Comm: swapper Tainted: G                 N 6.11.0-rc1 #1
> Tainted: [N]=TEST
> Hardware name: MPC8544DS e500v2 0x80210030 MPC8544 DS
> NIP:  c01f51b8 LR: c01f6fec CTR: 00000000
> REGS: c4135c40 TRAP: 0700   Tainted: G                 N  (6.11.0-rc1)
> MSR:  00029000 <CE,EE,ME>  CR: 24228288  XER: 20000000
> GPR00: c01f6fc0 c4135d30 c415bf20 c762e3f0 c29c9318 c7624ff8 0000026b b5fc2ea1
> GPR08: 00000000 00000000 5a5a5000 b7f4dd55 44228282 00000000 c0005014 00000000
> GPR16: 00000000 00000000 00000001 00050003 24228282 24228282 00000000 00000095
> GPR24: c1375b30 c4135de8 c4135e48 00050003 c762e3a0 c762e3f0 bffffff1 c7676a08
> NIP [c01f51b8] pmd_write.constprop.0.isra.0+0x4/0x8
> LR [c01f6fec] follow_page_mask+0x150/0x17c
> Call Trace:
> [c4135d30] [c4135de8] 0xc4135de8 (unreliable)
> [c4135d40] [c01f6fc0] follow_page_mask+0x124/0x17c
> [c4135d70] [c01f7170] __get_user_pages+0x158/0x5d8
> [c4135dd0] [c01f7750] get_user_pages_remote+0x160/0x560
> [c4135e30] [c026838c] get_arg_page+0xb0/0x25c
> [c4135e70] [c0268dd4] copy_string_kernel+0xf0/0x200
> [c4135eb0] [c026a0e4] kernel_execve+0xbc/0x190
> [c4135ee0] [c0005108] kernel_init+0xf4/0x1d4
> [c4135f00] [c0016224] ret_from_kernel_user_thread+0x10/0x18
> 
> This is with v6.11-rc1; the actually observed crash differs from test
> to test while running bisect.
> 
> I can't just revert the patch because subsequent patches depend on it.
> Is this confirmed to work on real hardware ? If so, do you have a
> suggestion how I could continue to use the mpc8544ds emulation for
> testing, or is it just dead ?
> 
> For reference, the configuration file is mpc85xx_defconfig.
> Bisect log is attached.
> 
> Thanks,
> Guenter
> 
> ---
> # bad: [8400291e289ee6b2bf9779ff1c83a291501f017b] Linux 6.11-rc1
> # good: [2c9b3512402ed192d1f43f4531fb5da947e72bd0] Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
> git bisect start 'v6.11-rc1' '2c9b3512402e'
> # bad: [6dc2e98d5f1de162d1777aee97e59d75d70d07c5] s390: Remove protvirt and kvm config guards for uv code
> git bisect bad 6dc2e98d5f1de162d1777aee97e59d75d70d07c5
> # bad: [30d77b7eef019fa4422980806e8b7cdc8674493e] mm/mglru: fix ineffective protection calculation
> git bisect bad 30d77b7eef019fa4422980806e8b7cdc8674493e
> # good: [c02525a33969000fa7b595b743deb4d79804916b] ftrace: unpoison ftrace_regs in ftrace_ops_list_func()
> git bisect good c02525a33969000fa7b595b743deb4d79804916b
> # good: [8ef6fd0e9ea83a792ba53882ddc6e0d38ce0d636] Merge branch 'mm-hotfixes-stable' into mm-stable to pick up "mm: fix crashes from deferred split racing folio migration", needed by "mm: migrate: split folio_migrate_mapping()".
> git bisect good 8ef6fd0e9ea83a792ba53882ddc6e0d38ce0d636
> # good: [a898530eea3d0ba08c17a60865995a3bb468d1bc] powerpc/64e: split out nohash Book3E 64-bit code
> git bisect good a898530eea3d0ba08c17a60865995a3bb468d1bc
> # bad: [00f58104202c472e487f0866fbd38832523fd4f9] mm: fix khugepaged activation policy
> git bisect bad 00f58104202c472e487f0866fbd38832523fd4f9
> # good: [e081c14744f4a93514069e1af1a7273d5451b909] powerpc/e500: remove enc and ind fields from struct mmu_psize_def
> git bisect good e081c14744f4a93514069e1af1a7273d5451b909
> # bad: [57fb15c32f4f6a4f1a58f1fbc58a799c3f975ed8] powerpc/64s: use contiguous PMD/PUD instead of HUGEPD
> git bisect bad 57fb15c32f4f6a4f1a58f1fbc58a799c3f975ed8
> # bad: [276d5affbbaea4d369d1e5b9711cb2951037f6ee] powerpc/e500: don't pre-check write access on data TLB error
> git bisect bad 276d5affbbaea4d369d1e5b9711cb2951037f6ee
> # bad: [84319905ca5f3759c42082e20ed978c81f4dead0] powerpc/e500: encode hugepage size in PTE bits
> git bisect bad 84319905ca5f3759c42082e20ed978c81f4dead0
> # bad: [6b0e82791bd03b2326c7f7d8c1124c825742f2a4] powerpc/e500: switch to 64 bits PGD on 85xx (32 bits)
> git bisect bad 6b0e82791bd03b2326c7f7d8c1124c825742f2a4
> # first bad commit: [6b0e82791bd03b2326c7f7d8c1124c825742f2a4] powerpc/e500: switch to 64 bits PGD on 85xx (32 bits)
> 
> C2 – Usage restreint
> 


^ permalink raw reply	[flat|nested] 28+ messages in thread

* Re: [PATCH v7 16/23] powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits)
       [not found]             ` <17eed040-969e-4d2c-b20b-ecfd93450901@csgroup.eu>
@ 2024-08-08 15:21               ` Guenter Roeck
  0 siblings, 0 replies; 28+ messages in thread
From: Guenter Roeck @ 2024-08-08 15:21 UTC (permalink / raw)
  To: Christophe Leroy
  Cc: linux-kernel@vger.kernel.org, Nicholas Piggin, linux-mm@kvack.org,
	Peter Xu, Jason Gunthorpe, Andrew Morton,
	linuxppc-dev@lists.ozlabs.org, Oscar Salvador

On 8/8/24 02:36, Christophe Leroy wrote:
> 
> 
> Le 07/08/2024 à 16:51, Guenter Roeck a écrit :
>> On 8/7/24 03:11, Christophe Leroy wrote:
>>> Hi,
>>>
>>> Le 31/07/2024 à 18:35, Guenter Roeck a écrit :
>>>> On 7/31/24 08:36, LEROY Christophe wrote:
>>>>>
>>>>> Hi Guenter,
>>>>> Thanks for this report. I'm afk this week, i"ll have a look at it in more détails next week.
>>>>> But to be sûre, does that Oops match the bisected commit ? Because pmd_leaf()  for e500 doesn't exist yet so pmd_write() shouldnt be called.
>>>>> I did validate all my changes with mpc8544 on qemu when i implemented this séries, using map_hugetlb mm selftest. What test tool are you using ?
>>>>
>>>> Nothing special; it is just a qemu boot test with various module test and debug options enabled,
>>>> using a root file system generated with buildroot.
>>>
>>> I still don't get anything with mpc85xx_defconfig.
>>>
>>> Can you tell with debug options you use and which module tests ?
>>>
>>
>> Please see https://eur01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fserver.roeck-us.net%2Fqemu%2Fppc-v6.11-rc2%2F&data=05%7C02%7Cchristophe.leroy%40csgroup.eu%7Cfd337af1375448bcda1508dcb6f06644%7C8b87af7d86474dc78df45f69a2011bb5%7C0%7C0%7C638586390853555531%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=7kihrxw5%2FrCI6TzmxGM56tEmghc1Bj7b1czXuM0%2BVrk%3D&reserved=0.
>>
> 
> Thanks,
> 
> CONFIG_SLUB_DEBUG_ON is what exhibits the problem.
> 
> I sent out a patch: https://patchwork.ozlabs.org/project/linuxppc-dev/patch/1cdaacb391cbd3e0240f0e0faf691202874e9422.1723109462.git.christophe.leroy@csgroup.eu/
> 
> With that patch I can successfully boot your config.
> 
> Can you give it a test ?
> 

Done; the patch fixes the problem for me.

Thanks!
Guenter




^ permalink raw reply	[flat|nested] 28+ messages in thread

end of thread, other threads:[~2024-08-08 15:21 UTC | newest]

Thread overview: 28+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2024-07-02 13:51 [PATCH v7 00/23] Reimplement huge pages without hugepd on powerpc (8xx, e500, book3s/64) Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 01/23] powerpc/64e: Remove unused IBM HTW code Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 02/23] powerpc/64e: Split out nohash Book3E 64-bit code Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 03/23] powerpc/64e: Drop E500 ifdefs in " Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 04/23] powerpc/64e: Drop MMU_FTR_TYPE_FSL_E checks " Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 05/23] powerpc/64e: Consolidate TLB miss handler patching Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 06/23] powerpc/64e: Drop unused TLB miss handlers Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 07/23] mm: Define __pte_leaf_size() to also take a PMD entry Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 08/23] mm: Provide mm_struct and address to huge_ptep_get() Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 09/23] powerpc/mm: Remove _PAGE_PSIZE Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 10/23] powerpc/mm: Fix __find_linux_pte() on 32 bits with PMD leaf entries Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 11/23] powerpc/mm: Allow hugepages without hugepd Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 12/23] powerpc/8xx: Fix size given to set_huge_pte_at() Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 13/23] powerpc/8xx: Rework support for 8M pages using contiguous PTE entries Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 14/23] powerpc/8xx: Simplify struct mmu_psize_def Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 15/23] powerpc/e500: Remove enc and ind fields from " Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 16/23] powerpc/e500: Switch to 64 bits PGD on 85xx (32 bits) Christophe Leroy
2024-07-29 22:10   ` Guenter Roeck
2024-07-31 15:36     ` LEROY Christophe
2024-07-31 16:35       ` Guenter Roeck
     [not found]         ` <b73e991e-5f66-455e-a271-e10511ebeaef@csgroup.eu>
     [not found]           ` <5cc43ed9-b4f8-49f5-99ee-b411bb144085@roeck-us.net>
     [not found]             ` <17eed040-969e-4d2c-b20b-ecfd93450901@csgroup.eu>
2024-08-08 15:21               ` Guenter Roeck
2024-07-02 13:51 ` [PATCH v7 17/23] powerpc/e500: Encode hugepage size in PTE bits Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 18/23] powerpc/e500: Don't pre-check write access on data TLB error Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 19/23] powerpc/e500: Free r10 for FIND_PTE Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 20/23] powerpc/e500: Use contiguous PMD instead of hugepd Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 21/23] powerpc/64s: Use contiguous PMD/PUD instead of HUGEPD Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 22/23] powerpc/mm: Remove hugepd leftovers Christophe Leroy
2024-07-02 13:51 ` [PATCH v7 23/23] mm: Remove CONFIG_ARCH_HAS_HUGEPD Christophe Leroy

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