The patch titled
Rework ptep_set_access_flags and fix sun4c
has been added to the -mm tree. Its filename is
rework-ptep_set_access_flags-and-fix-sun4c.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: Rework ptep_set_access_flags and fix sun4c
From: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
This patch reworks ptep_set_access_flags() and the callers so that the
comparison to the old PTE is done inside that function, which then returns
wether an update_mmu_cache() is needed. That allows fixing the sun4c
situation where update_mmu_cache() needs to be forced, always.
Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Cc: Hugh Dickins <hugh@xxxxxxxxxxx>
Cc: David Miller <davem@xxxxxxxxxxxxx>
Cc: Mark Fortescue <mark@xxxxxxxxxxxxxxxxxx>
Cc: William Lee Irwin III <wli@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/asm-generic/pgtable.h | 17 ++++++++++++-----
include/asm-i386/pgtable.h | 8 +++++---
include/asm-powerpc/pgtable-ppc32.h | 12 ++++++++----
include/asm-powerpc/pgtable-ppc64.h | 12 ++++++++----
include/asm-ppc/pgtable.h | 12 ++++++++----
include/asm-s390/pgtable.h | 7 ++++++-
include/asm-sparc/pgtable.h | 11 +++++++++++
include/asm-x86_64/pgtable.h | 14 ++++++++------
mm/memory.c | 13 ++++++-------
9 files changed, 72 insertions(+), 34 deletions(-)
diff -puN include/asm-generic/pgtable.h~rework-ptep_set_access_flags-and-fix-sun4c include/asm-generic/pgtable.h
--- a/include/asm-generic/pgtable.h~rework-ptep_set_access_flags-and-fix-sun4c
+++ a/include/asm-generic/pgtable.h
@@ -27,13 +27,20 @@ do { \
* Largely same as above, but only sets the access flags (dirty,
* accessed, and writable). Furthermore, we know it always gets set
* to a "more permissive" setting, which allows most architectures
- * to optimize this.
+ * to optimize this. We return wether the PTE actually changed, which
+ * in turn instructs the caller to do things like update__mmu_cache.
+ * This used to be done in the caller, but sparc needs minor faults to
+ * force that call on sun4c so we changed this macro slightly
*/
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
-do { \
- set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \
- flush_tlb_page(__vma, __address); \
-} while (0)
+({ \
+ int __changed = !pte_same(*(__ptep), __entry); \
+ if (__changed) { \
+ set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \
+ flush_tlb_page(__vma, __address); \
+ } \
+ __changed; \
+})
#endif
#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
diff -puN include/asm-i386/pgtable.h~rework-ptep_set_access_flags-and-fix-sun4c include/asm-i386/pgtable.h
--- a/include/asm-i386/pgtable.h~rework-ptep_set_access_flags-and-fix-sun4c
+++ a/include/asm-i386/pgtable.h
@@ -285,13 +285,15 @@ static inline pte_t native_local_ptep_ge
*/
#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
#define ptep_set_access_flags(vma, address, ptep, entry, dirty) \
-do { \
- if (dirty) { \
+({ \
+ int __changed = !pte_same(*(__ptep), __entry); \
+ if (__changed && dirty) { \
(ptep)->pte_low = (entry).pte_low; \
pte_update_defer((vma)->vm_mm, (address), (ptep)); \
flush_tlb_page(vma, address); \
} \
-} while (0)
+ __changed; \
+})
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
#define ptep_test_and_clear_dirty(vma, addr, ptep) ({ \
diff -puN include/asm-powerpc/pgtable-ppc32.h~rework-ptep_set_access_flags-and-fix-sun4c include/asm-powerpc/pgtable-ppc32.h
--- a/include/asm-powerpc/pgtable-ppc32.h~rework-ptep_set_access_flags-and-fix-sun4c
+++ a/include/asm-powerpc/pgtable-ppc32.h
@@ -673,10 +673,14 @@ static inline void __ptep_set_access_fla
}
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
- do { \
- __ptep_set_access_flags(__ptep, __entry, __dirty); \
- flush_tlb_page_nohash(__vma, __address); \
- } while(0)
+({ \
+ int __changed = !pte_same(*(__ptep), __entry); \
+ if (__changed) { \
+ __ptep_set_access_flags(__ptep, __entry, __dirty); \
+ flush_tlb_page_nohash(__vma, __address); \
+ } \
+ __changed; \
+})
/*
* Macro to mark a page protection value as "uncacheable".
diff -puN include/asm-powerpc/pgtable-ppc64.h~rework-ptep_set_access_flags-and-fix-sun4c include/asm-powerpc/pgtable-ppc64.h
--- a/include/asm-powerpc/pgtable-ppc64.h~rework-ptep_set_access_flags-and-fix-sun4c
+++ a/include/asm-powerpc/pgtable-ppc64.h
@@ -413,10 +413,14 @@ static inline void __ptep_set_access_fla
:"cc");
}
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
- do { \
- __ptep_set_access_flags(__ptep, __entry, __dirty); \
- flush_tlb_page_nohash(__vma, __address); \
- } while(0)
+({ \
+ int __changed = !pte_same(*(__ptep), __entry); \
+ if (__changed) { \
+ __ptep_set_access_flags(__ptep, __entry, __dirty); \
+ flush_tlb_page_nohash(__vma, __address); \
+ } \
+ __changed; \
+})
/*
* Macro to mark a page protection value as "uncacheable".
diff -puN include/asm-ppc/pgtable.h~rework-ptep_set_access_flags-and-fix-sun4c include/asm-ppc/pgtable.h
--- a/include/asm-ppc/pgtable.h~rework-ptep_set_access_flags-and-fix-sun4c
+++ a/include/asm-ppc/pgtable.h
@@ -694,10 +694,14 @@ static inline void __ptep_set_access_fla
}
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
- do { \
- __ptep_set_access_flags(__ptep, __entry, __dirty); \
- flush_tlb_page_nohash(__vma, __address); \
- } while(0)
+({ \
+ int __changed = !pte_same(*(__ptep), __entry); \
+ if (__changed) { \
+ __ptep_set_access_flags(__ptep, __entry, __dirty); \
+ flush_tlb_page_nohash(__vma, __address); \
+ } \
+ __changed; \
+})
/*
* Macro to mark a page protection value as "uncacheable".
diff -puN include/asm-s390/pgtable.h~rework-ptep_set_access_flags-and-fix-sun4c include/asm-s390/pgtable.h
--- a/include/asm-s390/pgtable.h~rework-ptep_set_access_flags-and-fix-sun4c
+++ a/include/asm-s390/pgtable.h
@@ -744,7 +744,12 @@ ptep_establish(struct vm_area_struct *vm
}
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
- ptep_establish(__vma, __address, __ptep, __entry)
+({ \
+ int __changed = !pte_same(*(__ptep), __entry); \
+ if (__changed) \
+ ptep_establish(__vma, __address, __ptep, __entry); \
+ __changed; \
+})
/*
* Test and clear dirty bit in storage key.
diff -puN include/asm-sparc/pgtable.h~rework-ptep_set_access_flags-and-fix-sun4c include/asm-sparc/pgtable.h
--- a/include/asm-sparc/pgtable.h~rework-ptep_set_access_flags-and-fix-sun4c
+++ a/include/asm-sparc/pgtable.h
@@ -446,6 +446,17 @@ extern int io_remap_pfn_range(struct vm_
#define GET_IOSPACE(pfn) (pfn >> (BITS_PER_LONG - 4))
#define GET_PFN(pfn) (pfn & 0x0fffffffUL)
+#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
+#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
+({ \
+ int __changed = !pte_same(*(__ptep), __entry); \
+ if (__changed) { \
+ set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \
+ flush_tlb_page(__vma, __address); \
+ } \
+ (sparc_cpu_model == sun4c) || __changed; \
+})
+
#include <asm-generic/pgtable.h>
#endif /* !(__ASSEMBLY__) */
diff -puN include/asm-x86_64/pgtable.h~rework-ptep_set_access_flags-and-fix-sun4c include/asm-x86_64/pgtable.h
--- a/include/asm-x86_64/pgtable.h~rework-ptep_set_access_flags-and-fix-sun4c
+++ a/include/asm-x86_64/pgtable.h
@@ -395,12 +395,14 @@ static inline pte_t pte_modify(pte_t pte
* bit at the same time. */
#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
- do { \
- if (__dirty) { \
- set_pte(__ptep, __entry); \
- flush_tlb_page(__vma, __address); \
- } \
- } while (0)
+({ \
+ int __changed = !pte_same(*(__ptep), __entry); \
+ if (__changed && __dirty) { \
+ set_pte(__ptep, __entry); \
+ flush_tlb_page(__vma, __address); \
+ } \
+ __changed; \
+})
/* Encode and de-code a swap entry */
#define __swp_type(x) (((x).val >> 1) & 0x3f)
diff -puN mm/memory.c~rework-ptep_set_access_flags-and-fix-sun4c mm/memory.c
--- a/mm/memory.c~rework-ptep_set_access_flags-and-fix-sun4c
+++ a/mm/memory.c
@@ -1697,9 +1697,10 @@ static int do_wp_page(struct mm_struct *
flush_cache_page(vma, address, pte_pfn(orig_pte));
entry = pte_mkyoung(orig_pte);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
- ptep_set_access_flags(vma, address, page_table, entry, 1);
- update_mmu_cache(vma, address, entry);
- lazy_mmu_prot_update(entry);
+ if (ptep_set_access_flags(vma, address, page_table, entry,1)) {
+ update_mmu_cache(vma, address, entry);
+ lazy_mmu_prot_update(entry);
+ }
ret |= VM_FAULT_WRITE;
goto unlock;
}
@@ -2508,10 +2509,9 @@ static inline int handle_pte_fault(struc
pte_t *pte, pmd_t *pmd, int write_access)
{
pte_t entry;
- pte_t old_entry;
spinlock_t *ptl;
- old_entry = entry = *pte;
+ entry = *pte;
if (!pte_present(entry)) {
if (pte_none(entry)) {
if (vma->vm_ops) {
@@ -2540,8 +2540,7 @@ static inline int handle_pte_fault(struc
entry = pte_mkdirty(entry);
}
entry = pte_mkyoung(entry);
- if (!pte_same(old_entry, entry)) {
- ptep_set_access_flags(vma, address, pte, entry, write_access);
+ if (ptep_set_access_flags(vma, address, pte, entry, write_access)) {
update_mmu_cache(vma, address, entry);
lazy_mmu_prot_update(entry);
} else {
_
Patches currently in -mm which might be from benh@xxxxxxxxxxxxxxxxxxx are
powerpc-fix.patch
do-not-select-macintosh-drivers-by-default.patch
8xx-mpc885ads-pcmcia-support.patch
8xx-mpc885ads-pcmcia-support-fix.patch
8xx-fix-whitespace-and-indentation.patch
dts-kill-hardcoded-phandles.patch
git-libata-all.patch
rework-ptep_set_access_flags-and-fix-sun4c.patch
fallocate-implementation-on-i86-x86_64-and-powerpc.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
