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* [PATCH 6/20] powerpc/mm: Add support for early ioremap on non-hash 64-bit processors
@ 2009-07-23  5:59 Benjamin Herrenschmidt
  0 siblings, 0 replies; 2+ messages in thread
From: Benjamin Herrenschmidt @ 2009-07-23  5:59 UTC (permalink / raw)
  To: linuxppc-dev

This adds some code to do early ioremap's using page tables instead of
bolting entries in the hash table. This will be used by the upcoming
64-bits BookE port.

The patch also changes the test for early vs. late ioremap to use
slab_is_available() instead of our old hackish mem_init_done.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---

 arch/powerpc/mm/pgtable_64.c |   59 +++++++++++++++++++++++++++++++++++++++----
 1 file changed, 54 insertions(+), 5 deletions(-)

--- linux-work.orig/arch/powerpc/mm/pgtable_64.c	2009-07-22 15:49:09.000000000 +1000
+++ linux-work/arch/powerpc/mm/pgtable_64.c	2009-07-23 14:56:39.000000000 +1000
@@ -33,6 +33,8 @@
 #include <linux/stddef.h>
 #include <linux/vmalloc.h>
 #include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/lmb.h>
 
 #include <asm/pgalloc.h>
 #include <asm/page.h>
@@ -55,19 +57,36 @@
 
 unsigned long ioremap_bot = IOREMAP_BASE;
 
+
+#ifdef CONFIG_PPC_MMU_NOHASH
+static void *early_alloc_pgtable(unsigned long size)
+{
+	void *pt;
+
+	if (init_bootmem_done)
+		pt = __alloc_bootmem(size, size, __pa(MAX_DMA_ADDRESS));
+	else
+		pt = __va(lmb_alloc_base(size, size,
+					 __pa(MAX_DMA_ADDRESS)));
+	memset(pt, 0, size);
+
+	return pt;
+}
+#endif /* CONFIG_PPC_MMU_NOHASH */
+
 /*
- * map_io_page currently only called by __ioremap
- * map_io_page adds an entry to the ioremap page table
+ * map_kernel_page currently only called by __ioremap
+ * map_kernel_page adds an entry to the ioremap page table
  * and adds an entry to the HPT, possibly bolting it
  */
-static int map_io_page(unsigned long ea, unsigned long pa, int flags)
+static int map_kernel_page(unsigned long ea, unsigned long pa, int flags)
 {
 	pgd_t *pgdp;
 	pud_t *pudp;
 	pmd_t *pmdp;
 	pte_t *ptep;
 
-	if (mem_init_done) {
+	if (slab_is_available()) {
 		pgdp = pgd_offset_k(ea);
 		pudp = pud_alloc(&init_mm, pgdp, ea);
 		if (!pudp)
@@ -81,6 +100,35 @@ static int map_io_page(unsigned long ea,
 		set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
 							  __pgprot(flags)));
 	} else {
+#ifdef CONFIG_PPC_MMU_NOHASH
+		/* Warning ! This will blow up if bootmem is not initialized
+		 * which our ppc64 code is keen to do that, we'll need to
+		 * fix it and/or be more careful
+		 */
+		pgdp = pgd_offset_k(ea);
+#ifdef PUD_TABLE_SIZE
+		if (pgd_none(*pgdp)) {
+			pudp = early_alloc_pgtable(PUD_TABLE_SIZE);
+			BUG_ON(pudp == NULL);
+			pgd_populate(&init_mm, pgdp, pudp);
+		}
+#endif /* PUD_TABLE_SIZE */
+		pudp = pud_offset(pgdp, ea);
+		if (pud_none(*pudp)) {
+			pmdp = early_alloc_pgtable(PMD_TABLE_SIZE);
+			BUG_ON(pmdp == NULL);
+			pud_populate(&init_mm, pudp, pmdp);
+		}
+		pmdp = pmd_offset(pudp, ea);
+		if (!pmd_present(*pmdp)) {
+			ptep = early_alloc_pgtable(PAGE_SIZE);
+			BUG_ON(ptep == NULL);
+			pmd_populate_kernel(&init_mm, pmdp, ptep);
+		}
+		ptep = pte_offset_kernel(pmdp, ea);
+		set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT,
+							  __pgprot(flags)));
+#else /* CONFIG_PPC_MMU_NOHASH */
 		/*
 		 * If the mm subsystem is not fully up, we cannot create a
 		 * linux page table entry for this mapping.  Simply bolt an
@@ -93,6 +141,7 @@ static int map_io_page(unsigned long ea,
 			       "memory at %016lx !\n", pa);
 			return -ENOMEM;
 		}
+#endif /* !CONFIG_PPC_MMU_NOHASH */
 	}
 	return 0;
 }
@@ -124,7 +173,7 @@ void __iomem * __ioremap_at(phys_addr_t 
 	WARN_ON(size & ~PAGE_MASK);
 
 	for (i = 0; i < size; i += PAGE_SIZE)
-		if (map_io_page((unsigned long)ea+i, pa+i, flags))
+		if (map_kernel_page((unsigned long)ea+i, pa+i, flags))
 			return NULL;
 
 	return (void __iomem *)ea;

^ permalink raw reply	[flat|nested] 2+ messages in thread
* [PATCH 0/20] powerpc: base 64-bit Book3E processor support (v2)
@ 2009-07-24  9:15 Benjamin Herrenschmidt
  2009-07-24  9:15 ` [PATCH 6/20] powerpc/mm: Add support for early ioremap on non-hash 64-bit processors Benjamin Herrenschmidt
  0 siblings, 1 reply; 2+ messages in thread
From: Benjamin Herrenschmidt @ 2009-07-24  9:15 UTC (permalink / raw)
  To: linuxppc-dev

Here is a series of patches that implement some basic support
for 64-bit Book3E processors that comply to architecture 2.06.

There is no specific processor announced yet. The patches make
some shortcut which means they currently rely on an implementation
that supports MMU v2 with support for the "HES" feature (HW entry
select) and with support for the "TLB reservation" feature. They
also assume a single unified TLB array. I shouldn't be very hard
to implement support for other variants of the architecture on
top of this though.

The current set of patch has no proper support yet for hugetlb,
nor for "special" interrupt levels (debug, critical and machine
check). Some minimal support for debug/critical levels is provided
specifically for the "Debug" interrupt (single step etc...) only
when it occurs from within user space code. 

The intend is to merge these in 2.6.32. They rely on pretty much
all the other patches I've been posting lately including the
generic changes to add the virtual address argument to pte_free_tlb.

v2. Various fixes, some addressing comments recieved and a whole
bunch fixing other issues including breakage of existing platforms

^ permalink raw reply	[flat|nested] 2+ messages in thread
end of thread, other threads:[~2009-07-24  9:15 UTC | newest]

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2009-07-23  5:59 [PATCH 6/20] powerpc/mm: Add support for early ioremap on non-hash 64-bit processors Benjamin Herrenschmidt
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2009-07-24  9:15 [PATCH 0/20] powerpc: base 64-bit Book3E processor support (v2) Benjamin Herrenschmidt
2009-07-24  9:15 ` [PATCH 6/20] powerpc/mm: Add support for early ioremap on non-hash 64-bit processors Benjamin Herrenschmidt

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