[PATCH v5 06/18] powerpc/mm: Allow hugepages without hugepd

Christophe Leroy
2024-06-10T05:55:31Z

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