Some changes done a while ago to avoid pounding on ptep_set_access_flags and
update_mmu_cache in some race situations break sun4c which requires
update_mmu_cache() to always be called on minor faults.
This patch reworks ptep_set_access_flags() semantics, implementations and
callers so that it's now responsible for returning whether an update is
necessary or not (basically whether the PTE actually changed). This allow
fixing the sparc implementation to always return 1 on sun4c.
[akpm@linux-foundation.org: fixes, cleanups]
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: David Miller <davem@davemloft.net>
Cc: Mark Fortescue <mark@mtfhpc.demon.co.uk>
Acked-by: William Lee Irwin III <wli@holomorphy.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 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
* 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. We return whether 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) \
*/
#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
#endif
#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
*/
#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
#define ptep_set_access_flags(vma, address, ptep, entry, dirty) \
*/
#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 && dirty) { \
(ptep)->pte_low = (entry).pte_low; \
pte_update_defer((vma)->vm_mm, (address), (ptep)); \
flush_tlb_page(vma, address); \
} \
(ptep)->pte_low = (entry).pte_low; \
pte_update_defer((vma)->vm_mm, (address), (ptep)); \
flush_tlb_page(vma, address); \
} \
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
#define ptep_test_and_clear_dirty(vma, addr, ptep) ({ \
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
#define ptep_test_and_clear_dirty(vma, addr, ptep) ({ \
* daccess_bit in ivt.S).
*/
#ifdef CONFIG_SMP
* daccess_bit in ivt.S).
*/
#ifdef CONFIG_SMP
-# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
-do { \
- if (__safely_writable) { \
- set_pte(__ptep, __entry); \
- flush_tlb_page(__vma, __addr); \
- } \
-} while (0)
+# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
+({ \
+ int __changed = !pte_same(*(__ptep), __entry); \
+ if (__changed && __safely_writable) { \
+ set_pte(__ptep, __entry); \
+ flush_tlb_page(__vma, __addr); \
+ } \
+ __changed; \
+})
-# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
- ptep_establish(__vma, __addr, __ptep, __entry)
+# define ptep_set_access_flags(__vma, __addr, __ptep, __entry, __safely_writable) \
+({ \
+ int __changed = !pte_same(*(__ptep), __entry); \
+ if (__changed) \
+ ptep_establish(__vma, __addr, __ptep, __entry); \
+ __changed; \
+})
#endif
# ifdef CONFIG_VIRTUAL_MEM_MAP
#endif
# ifdef CONFIG_VIRTUAL_MEM_MAP
}
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
}
#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".
/*
* Macro to mark a page protection value as "uncacheable".
:"cc");
}
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
:"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".
/*
* Macro to mark a page protection value as "uncacheable".
}
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
}
#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".
/*
* Macro to mark a page protection value as "uncacheable".
}
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
}
#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.
/*
* Test and clear dirty bit in storage key.
#define GET_IOSPACE(pfn) (pfn >> (BITS_PER_LONG - 4))
#define GET_PFN(pfn) (pfn & 0x0fffffffUL)
#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__) */
#include <asm-generic/pgtable.h>
#endif /* !(__ASSEMBLY__) */
* bit at the same time. */
#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
* 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)
/* Encode and de-code a swap entry */
#define __swp_type(x) (((x).val >> 1) & 0x3f)
pte_t entry;
entry = pte_mkwrite(pte_mkdirty(*ptep));
pte_t entry;
entry = pte_mkwrite(pte_mkdirty(*ptep));
- ptep_set_access_flags(vma, address, ptep, entry, 1);
- update_mmu_cache(vma, address, entry);
- lazy_mmu_prot_update(entry);
+ if (ptep_set_access_flags(vma, address, ptep, entry, 1)) {
+ update_mmu_cache(vma, address, entry);
+ lazy_mmu_prot_update(entry);
+ }
flush_cache_page(vma, address, pte_pfn(orig_pte));
entry = pte_mkyoung(orig_pte);
entry = maybe_mkwrite(pte_mkdirty(entry), vma);
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;
}
ret |= VM_FAULT_WRITE;
goto unlock;
}
pte_t *pte, pmd_t *pmd, int write_access)
{
pte_t entry;
pte_t *pte, pmd_t *pmd, int write_access)
{
pte_t entry;
- old_entry = entry = *pte;
if (!pte_present(entry)) {
if (pte_none(entry)) {
if (vma->vm_ops) {
if (!pte_present(entry)) {
if (pte_none(entry)) {
if (vma->vm_ops) {
entry = pte_mkdirty(entry);
}
entry = pte_mkyoung(entry);
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 {
update_mmu_cache(vma, address, entry);
lazy_mmu_prot_update(entry);
} else {