--- v4
+++ v2
@@ -1,40 +1,125 @@
-We now use physical address in upper page table tree levels. Even though
-they are aligned to their size, for the masked bits we use the
-overloaded bit positions as per PowerISA 3.0. We keep the bad bits check
-as it is, and will use conditional there when adding radix. Bad bits
-check also check for reserved bits and we oveload some of the reserved
-fields of radix in hash config.
+With next generation power processor, we are having a new mmu model
+[1] that require us to maintain a different linux page table format.
+
+Inorder to support both current and future ppc64 systems with a single
+kernel we need to make sure kernel can select between different page
+table format at runtime. With the new MMU (radix MMU) added, we will
+have to dynamically switch between different protection map. Hence
+override vm_get_page_prot instead of using arch_vm_get_page_prot. We
+also drop arch_vm_get_page_prot since only powerpc used it.
+
+[1] http://ibm.biz/power-isa3 (Needs registration).
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
---
- arch/powerpc/include/asm/book3s/64/hash-64k.h | 15 ++++++---------
- 1 file changed, 6 insertions(+), 9 deletions(-)
+ arch/powerpc/include/asm/book3s/64/hash.h | 3 +++
+ arch/powerpc/include/asm/mman.h | 6 ------
+ arch/powerpc/mm/hash_utils_64.c | 19 +++++++++++++++++++
+ include/linux/mman.h | 4 ----
+ mm/mmap.c | 9 ++++++---
+ 5 files changed, 28 insertions(+), 13 deletions(-)
-diff --git a/arch/powerpc/include/asm/book3s/64/hash-64k.h b/arch/powerpc/include/asm/book3s/64/hash-64k.h
-index f0f5f91d7909..60c2c912c3a7 100644
---- a/arch/powerpc/include/asm/book3s/64/hash-64k.h
-+++ b/arch/powerpc/include/asm/book3s/64/hash-64k.h
-@@ -60,15 +60,12 @@
- #define PTE_FRAG_SIZE_SHIFT 12
- #define PTE_FRAG_SIZE (1UL << PTE_FRAG_SIZE_SHIFT)
+diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
+index 6aae0b0b649b..c568eaa1c26d 100644
+--- a/arch/powerpc/include/asm/book3s/64/hash.h
++++ b/arch/powerpc/include/asm/book3s/64/hash.h
+@@ -538,6 +538,9 @@ static inline pgprot_t pgprot_writecombine(pgprot_t prot)
+ return pgprot_noncached_wc(prot);
+ }
--/*
-- * Bits to mask out from a PMD to get to the PTE page
-- * PMDs point to PTE table fragments which are PTE_FRAG_SIZE aligned.
-- */
--#define PMD_MASKED_BITS (PTE_FRAG_SIZE - 1)
--/* Bits to mask out from a PGD/PUD to get to the PMD page */
--#define PUD_MASKED_BITS 0x1ff
--/* FIXME!! Will be fixed in next patch */
--#define PGD_MASKED_BITS 0
-+/* Bits to mask out from a PMD to get to the PTE page */
-+#define PMD_MASKED_BITS 0xc0000000000000ffUL
-+/* Bits to mask out from a PUD to get to the PMD page */
-+#define PUD_MASKED_BITS 0xc0000000000000ffUL
-+/* Bits to mask out from a PGD to get to the PUD page */
-+#define PGD_MASKED_BITS 0xc0000000000000ffUL
++extern pgprot_t vm_get_page_prot(unsigned long vm_flags);
++#define vm_get_page_prot vm_get_page_prot
++
+ #ifdef CONFIG_TRANSPARENT_HUGEPAGE
+ extern void hpte_do_hugepage_flush(struct mm_struct *mm, unsigned long addr,
+ pmd_t *pmdp, unsigned long old_pmd);
+diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h
+index 8565c254151a..9f48698af024 100644
+--- a/arch/powerpc/include/asm/mman.h
++++ b/arch/powerpc/include/asm/mman.h
+@@ -24,12 +24,6 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot)
+ }
+ #define arch_calc_vm_prot_bits(prot) arch_calc_vm_prot_bits(prot)
- #ifndef __ASSEMBLY__
+-static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags)
+-{
+- return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0);
+-}
+-#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags)
+-
+ static inline int arch_validate_prot(unsigned long prot)
+ {
+ if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | PROT_SAO))
+diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
+index ba59d5977f34..3199bbc654c5 100644
+--- a/arch/powerpc/mm/hash_utils_64.c
++++ b/arch/powerpc/mm/hash_utils_64.c
+@@ -1564,3 +1564,22 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
+ /* Finally limit subsequent allocations */
+ memblock_set_current_limit(ppc64_rma_size);
+ }
++
++static pgprot_t hash_protection_map[16] = {
++ __P000, __P001, __P010, __P011, __P100,
++ __P101, __P110, __P111, __S000, __S001,
++ __S010, __S011, __S100, __S101, __S110, __S111
++};
++
++pgprot_t vm_get_page_prot(unsigned long vm_flags)
++{
++ pgprot_t prot_soa = __pgprot(0);
++
++ if (vm_flags & VM_SAO)
++ prot_soa = __pgprot(_PAGE_SAO);
++
++ return __pgprot(pgprot_val(hash_protection_map[vm_flags &
++ (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
++ pgprot_val(prot_soa));
++}
++EXPORT_SYMBOL(vm_get_page_prot);
+diff --git a/include/linux/mman.h b/include/linux/mman.h
+index 16373c8f5f57..d44abea464e2 100644
+--- a/include/linux/mman.h
++++ b/include/linux/mman.h
+@@ -38,10 +38,6 @@ static inline void vm_unacct_memory(long pages)
+ #define arch_calc_vm_prot_bits(prot) 0
+ #endif
+-#ifndef arch_vm_get_page_prot
+-#define arch_vm_get_page_prot(vm_flags) __pgprot(0)
+-#endif
+-
+ #ifndef arch_validate_prot
+ /*
+ * This is called from mprotect(). PROT_GROWSDOWN and PROT_GROWSUP have
+diff --git a/mm/mmap.c b/mm/mmap.c
+index cfc0cdca421e..aa2e901029d0 100644
+--- a/mm/mmap.c
++++ b/mm/mmap.c
+@@ -92,6 +92,10 @@ static void unmap_region(struct mm_struct *mm,
+ * x: (no) no x: (no) yes x: (no) yes x: (yes) yes
+ *
+ */
++/*
++ * Give arch an option to override the below in dynamic matter
++ */
++#ifndef vm_get_page_prot
+ pgprot_t protection_map[16] = {
+ __P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111,
+ __S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
+@@ -99,11 +103,10 @@ pgprot_t protection_map[16] = {
+
+ pgprot_t vm_get_page_prot(unsigned long vm_flags)
+ {
+- return __pgprot(pgprot_val(protection_map[vm_flags &
+- (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) |
+- pgprot_val(arch_vm_get_page_prot(vm_flags)));
++ return protection_map[vm_flags & (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)];
+ }
+ EXPORT_SYMBOL(vm_get_page_prot);
++#endif
+
+ static pgprot_t vm_pgprot_modify(pgprot_t oldprot, unsigned long vm_flags)
+ {
--
2.5.0