powerpc/mm: Add helper for converting pte bit to hpte bits
Instead of open coding it in multiple code paths, export the helper
and add more documentation. Also make sure we don't make assumption
regarding pte bit position
Acked-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/book3s/64/hash.h b/arch/powerpc/include/asm/book3s/64/hash.h
index e4ea9d7..9c212449 100644
--- a/arch/powerpc/include/asm/book3s/64/hash.h
+++ b/arch/powerpc/include/asm/book3s/64/hash.h
@@ -236,6 +236,7 @@
pmd_t *pmdp,
unsigned long clr,
unsigned long set);
+extern unsigned long htab_convert_pte_flags(unsigned long pteflags);
/* Atomic PTE updates */
static inline unsigned long pte_update(struct mm_struct *mm,
unsigned long addr,
diff --git a/arch/powerpc/mm/hash64_4k.c b/arch/powerpc/mm/hash64_4k.c
index 3b49c6f..ee86313 100644
--- a/arch/powerpc/mm/hash64_4k.c
+++ b/arch/powerpc/mm/hash64_4k.c
@@ -53,18 +53,7 @@
* PP bits. _PAGE_USER is already PP bit 0x2, so we only
* need to add in 0x1 if it's a read-only user page
*/
- rflags = new_pte & _PAGE_USER;
- if ((new_pte & _PAGE_USER) && !((new_pte & _PAGE_RW) &&
- (new_pte & _PAGE_DIRTY)))
- rflags |= 0x1;
- /*
- * _PAGE_EXEC -> HW_NO_EXEC since it's inverted
- */
- rflags |= ((new_pte & _PAGE_EXEC) ? 0 : HPTE_R_N);
- /*
- * Always add C and Memory coherence bit
- */
- rflags |= HPTE_R_C | HPTE_R_M;
+ rflags = htab_convert_pte_flags(new_pte);
/*
* Add in WIMG bits
*/
diff --git a/arch/powerpc/mm/hash64_64k.c b/arch/powerpc/mm/hash64_64k.c
index fc0898e..b14280e 100644
--- a/arch/powerpc/mm/hash64_64k.c
+++ b/arch/powerpc/mm/hash64_64k.c
@@ -85,22 +85,7 @@
* Handle the subpage protection bits
*/
subpg_pte = new_pte & ~subpg_prot;
- /*
- * PP bits. _PAGE_USER is already PP bit 0x2, so we only
- * need to add in 0x1 if it's a read-only user page
- */
- rflags = subpg_pte & _PAGE_USER;
- if ((subpg_pte & _PAGE_USER) && !((subpg_pte & _PAGE_RW) &&
- (subpg_pte & _PAGE_DIRTY)))
- rflags |= 0x1;
- /*
- * _PAGE_EXEC -> HW_NO_EXEC since it's inverted
- */
- rflags |= ((subpg_pte & _PAGE_EXEC) ? 0 : HPTE_R_N);
- /*
- * Always add C and Memory coherence bit
- */
- rflags |= HPTE_R_C | HPTE_R_M;
+ rflags = htab_convert_pte_flags(subpg_pte);
/*
* Add in WIMG bits
*/
@@ -271,22 +256,8 @@
new_pte |= _PAGE_DIRTY;
} while (old_pte != __cmpxchg_u64((unsigned long *)ptep,
old_pte, new_pte));
- /*
- * PP bits. _PAGE_USER is already PP bit 0x2, so we only
- * need to add in 0x1 if it's a read-only user page
- */
- rflags = new_pte & _PAGE_USER;
- if ((new_pte & _PAGE_USER) && !((new_pte & _PAGE_RW) &&
- (new_pte & _PAGE_DIRTY)))
- rflags |= 0x1;
- /*
- * _PAGE_EXEC -> HW_NO_EXEC since it's inverted
- */
- rflags |= ((new_pte & _PAGE_EXEC) ? 0 : HPTE_R_N);
- /*
- * Always add C and Memory coherence bit
- */
- rflags |= HPTE_R_C | HPTE_R_M;
+
+ rflags = htab_convert_pte_flags(new_pte);
/*
* Add in WIMG bits
*/
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index cab2deb..6c67bd0 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -159,20 +159,26 @@
},
};
-static unsigned long htab_convert_pte_flags(unsigned long pteflags)
+unsigned long htab_convert_pte_flags(unsigned long pteflags)
{
- unsigned long rflags = pteflags & 0x1fa;
+ unsigned long rflags = 0;
/* _PAGE_EXEC -> NOEXEC */
if ((pteflags & _PAGE_EXEC) == 0)
rflags |= HPTE_R_N;
-
- /* PP bits. PAGE_USER is already PP bit 0x2, so we only
- * need to add in 0x1 if it's a read-only user page
+ /*
+ * PP bits:
+ * Linux use slb key 0 for kernel and 1 for user.
+ * kernel areas are mapped by PP bits 00
+ * and and there is no kernel RO (_PAGE_KERNEL_RO).
+ * User area mapped by 0x2 and read only use by
+ * 0x3.
*/
- if ((pteflags & _PAGE_USER) && !((pteflags & _PAGE_RW) &&
- (pteflags & _PAGE_DIRTY)))
- rflags |= 1;
+ if (pteflags & _PAGE_USER) {
+ rflags |= 0x2;
+ if (!((pteflags & _PAGE_RW) && (pteflags & _PAGE_DIRTY)))
+ rflags |= 0x1;
+ }
/*
* Always add "C" bit for perf. Memory coherence is always enabled
*/
diff --git a/arch/powerpc/mm/hugepage-hash64.c b/arch/powerpc/mm/hugepage-hash64.c
index 4d87122..91fcac6 100644
--- a/arch/powerpc/mm/hugepage-hash64.c
+++ b/arch/powerpc/mm/hugepage-hash64.c
@@ -54,18 +54,7 @@
new_pmd |= _PAGE_DIRTY;
} while (old_pmd != __cmpxchg_u64((unsigned long *)pmdp,
old_pmd, new_pmd));
- /*
- * PP bits. _PAGE_USER is already PP bit 0x2, so we only
- * need to add in 0x1 if it's a read-only user page
- */
- rflags = new_pmd & _PAGE_USER;
- if ((new_pmd & _PAGE_USER) && !((new_pmd & _PAGE_RW) &&
- (new_pmd & _PAGE_DIRTY)))
- rflags |= 0x1;
- /*
- * _PAGE_EXEC -> HW_NO_EXEC since it's inverted
- */
- rflags |= ((new_pmd & _PAGE_EXEC) ? 0 : HPTE_R_N);
+ rflags = htab_convert_pte_flags(new_pmd);
#if 0
if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE)) {
diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
index 7584e84..304c852 100644
--- a/arch/powerpc/mm/hugetlbpage-hash64.c
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -59,10 +59,8 @@
new_pte |= _PAGE_DIRTY;
} while(old_pte != __cmpxchg_u64((unsigned long *)ptep,
old_pte, new_pte));
+ rflags = htab_convert_pte_flags(new_pte);
- rflags = 0x2 | (!(new_pte & _PAGE_RW));
- /* _PAGE_EXEC -> HW_NO_EXEC since it's inverted */
- rflags |= ((new_pte & _PAGE_EXEC) ? 0 : HPTE_R_N);
sz = ((1UL) << shift);
if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
/* No CPU has hugepages but lacks no execute, so we