flush icache for ia64 take4.
This patch is against 2.6.23-rc1.

Changes V5 -> V6:
  - no changes. (added new patches to the patch set)

Changes V4 -> V5:
  - removed sync_icache_dcache from do_wp_page() page reuse case.

Changes v3 -> v4:
  - avoid implementing flush_(i)cache_pages().
  - added sync_icache_dcache() call.
  - change Documentation/cachetlb.txt

Current ia64 kernel flushes icache by lazy_mmu_prot_update() *after*
set_pte(). This is wrong. This patch removes lazy_mmu_prot_update and
add sync_icache_dcache(). sync_icache_dcache() is called before set_pte()
if necessary and synchronize icache with dcache (fc.i instruction).

This patch fixes SIGILL problem on NFS/ia64.

About Icache-Dcache inconsistency in ia64
 - When the cache line is modified, Icache and Dcache are purged.

 - When I-cache misses, I-cache will access just the lower layer cache(memory).
   Then, If the lower_layer_cache is not up-to-date, I-cache will see
   old information. For avoiding this case, Icache-Dcache synchronization(fc.i)
   is necessary. (Icache-Dcache synchronization means making Dcache and lower
   layer unified cache(memory) consistent.)

Details:
 - In general, cache flushing macro are used for virtually tagged caches.
   IA64 has physically tagged caches but doesn't guarantee consistency 
   between Icache and Dcache. So, new macro, sync_icache_dcache() is added.
   This is NO-OP in other archs.
 - sync_icache_dcache() only works if pte is executable.
 - sync_icache_dcache must be called before set_pte().
 - A page which is consistent is marked as PG_arch_1.

About changes in generic codes:
 - do_wp_page() ....need to sync newly copied page.
                    Here, lazy_mmu_prot_update() was done before set_pte().
                    This was because SIGILL in JAVA was reported and quick
                    fix was applied.

 - do_anonymous_page() .... newly installed anon pages doesn't contains any
                    instruction when set_pte() is executed, icache-dcache
                    synchronization is not necessary.

 - __do_fault() .... need to sync newly-installed page.

 - handle_pte_fault() .... just changes access bit...then, no need to sync.

 - remove_migration_pte().... need to sync newly-installed page.

 
 - change_pte_range() .... need to sync icache-dcache. When a user writes
                     instruction into the page and modifies protection to be    
                     executable, it should be synced.

 - hugetlb_change_protection() .... Maybe cache will be expired...but
                          it is safe to sync Icache before set_pte().

 - page_mkclean_one() .... no need to sync icache-dcache. There is no page
                           contents modification. And there is no protection 
                           change.

Thanks to Zoltan Menyhart for his advices.

Signed-off-by: KAMEZAWA Hiroyuki <[EMAIL PROTECTED]>

---
 Documentation/cachetlb.txt    |   11 +++++++----
 arch/ia64/mm/init.c           |    6 ++----
 include/asm-generic/pgtable.h |    8 ++++----
 include/asm-ia64/pgtable.h    |   15 ++++++++++-----
 mm/hugetlb.c                  |    3 +--
 mm/memory.c                   |    7 ++-----
 mm/migrate.c                  |    2 +-
 mm/mprotect.c                 |    2 +-
 mm/rmap.c                     |    1 -
 9 files changed, 28 insertions(+), 27 deletions(-)

Index: linux-2.6.23-rc1.test/include/asm-generic/pgtable.h
===================================================================
--- linux-2.6.23-rc1.test.orig/include/asm-generic/pgtable.h
+++ linux-2.6.23-rc1.test/include/asm-generic/pgtable.h
@@ -124,14 +124,14 @@ static inline void ptep_set_wrprotect(st
 #define pgd_offset_gate(mm, addr)      pgd_offset(mm, addr)
 #endif
 
-#ifndef __HAVE_ARCH_LAZY_MMU_PROT_UPDATE
-#define lazy_mmu_prot_update(pte)      do { } while (0)
-#endif
-
 #ifndef __HAVE_ARCH_MOVE_PTE
 #define move_pte(pte, prot, old_addr, new_addr)        (pte)
 #endif
 
+#ifndef __HAVE_ARCH_SYNC_ICACHE_DCACHE
+#define sync_icache_dcache(pte)                do {} while (0)
+#endif
+
 /*
  * A facility to provide lazy MMU batching.  This allows PTE updates and
  * page invalidations to be delayed until a call to leave lazy MMU mode
Index: linux-2.6.23-rc1.test/include/asm-ia64/pgtable.h
===================================================================
--- linux-2.6.23-rc1.test.orig/include/asm-ia64/pgtable.h
+++ linux-2.6.23-rc1.test/include/asm-ia64/pgtable.h
@@ -484,11 +484,18 @@ extern struct page *zero_page_memmap_ptr
 #endif
 
 /*
- * IA-64 doesn't have any external MMU info: the page tables contain all the 
necessary
- * information.  However, we use this routine to take care of any (delayed) 
i-cache
- * flushing that may be necessary.
+ * IA-64 doesn't guarantee Icache is consistent with Dcache. For ensure
+ * Icache consistency, we have to synchronize them before setting pte
+ * as an executable pte.
  */
-extern void lazy_mmu_prot_update (pte_t pte);
+extern void __sync_icache_dcache(pte_t pte);
+static inline void sync_icache_dcache(pte_t pte)
+{
+       if (pte_exec(pte))
+               __sync_icache_dcache(pte);
+}
+#define __HAVE_ARCH_SYNC_ICACHE_DCACHE
+
 
 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 /*
@@ -578,7 +585,6 @@ extern void lazy_mmu_prot_update (pte_t 
 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
 #define __HAVE_ARCH_PTE_SAME
 #define __HAVE_ARCH_PGD_OFFSET_GATE
-#define __HAVE_ARCH_LAZY_MMU_PROT_UPDATE
 
 #ifndef CONFIG_PGTABLE_4
 #include <asm-generic/pgtable-nopud.h>
Index: linux-2.6.23-rc1.test/Documentation/cachetlb.txt
===================================================================
--- linux-2.6.23-rc1.test.orig/Documentation/cachetlb.txt
+++ linux-2.6.23-rc1.test/Documentation/cachetlb.txt
@@ -133,11 +133,14 @@ changes occur:
        The ia64 sn2 platform is one example of a platform
        that uses this interface.
 
-8) void lazy_mmu_prot_update(pte_t pte)
-       This interface is called whenever the protection on
-       any user PTEs change.  This interface provides a notification
-       to architecture specific code to take appropriate action.
+8) void sync_icache_dcache(pte_t pte)
+       This interface is used for synchronize icache and dcache.
+       Even if the cache is physically tagged, some archs doesn't
+       guarantee consistency between I-cache and D-cache. In such arch,
+       we need to synchronize I-cache and D-cache before installing
+       executable pages.
 
+       This is used only for ia64 now.
 
 Next, we have the cache flushing interfaces.  In general, when Linux
 is changing an existing virtual-->physical mapping to a new value,
Index: linux-2.6.23-rc1.test/mm/memory.c
===================================================================
--- linux-2.6.23-rc1.test.orig/mm/memory.c
+++ linux-2.6.23-rc1.test/mm/memory.c
@@ -1699,7 +1699,6 @@ static int do_wp_page(struct mm_struct *
                entry = maybe_mkwrite(pte_mkdirty(entry), vma);
                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;
@@ -1741,7 +1740,7 @@ gotten:
                flush_cache_page(vma, address, pte_pfn(orig_pte));
                entry = mk_pte(new_page, vma->vm_page_prot);
                entry = maybe_mkwrite(pte_mkdirty(entry), vma);
-               lazy_mmu_prot_update(entry);
+               sync_icache_dcache(entry);
                /*
                 * Clear the pte entry and flush it first, before updating the
                 * pte with the new entry. This will avoid a race condition
@@ -2286,7 +2285,6 @@ static int do_anonymous_page(struct mm_s
 
        /* No need to invalidate - it was non-present before */
        update_mmu_cache(vma, address, entry);
-       lazy_mmu_prot_update(entry);
 unlock:
        pte_unmap_unlock(page_table, ptl);
        return 0;
@@ -2419,6 +2417,7 @@ static int __do_fault(struct mm_struct *
        if (likely(pte_same(*page_table, orig_pte))) {
                flush_icache_page(vma, page);
                entry = mk_pte(page, vma->vm_page_prot);
+               sync_icache_dcache(entry);
                if (flags & FAULT_FLAG_WRITE)
                        entry = maybe_mkwrite(pte_mkdirty(entry), vma);
                set_pte_at(mm, address, page_table, entry);
@@ -2437,7 +2436,6 @@ static int __do_fault(struct mm_struct *
 
                /* no need to invalidate: a not-present page won't be cached */
                update_mmu_cache(vma, address, entry);
-               lazy_mmu_prot_update(entry);
        } else {
                if (anon)
                        page_cache_release(page);
@@ -2611,7 +2609,6 @@ static inline int handle_pte_fault(struc
        entry = pte_mkyoung(entry);
        if (ptep_set_access_flags(vma, address, pte, entry, write_access)) {
                update_mmu_cache(vma, address, entry);
-               lazy_mmu_prot_update(entry);
        } else {
                /*
                 * This is needed only for protection faults but the arch code
Index: linux-2.6.23-rc1.test/mm/migrate.c
===================================================================
--- linux-2.6.23-rc1.test.orig/mm/migrate.c
+++ linux-2.6.23-rc1.test/mm/migrate.c
@@ -173,6 +173,7 @@ static void remove_migration_pte(struct 
        if (is_write_migration_entry(entry))
                pte = pte_mkwrite(pte);
        flush_cache_page(vma, addr, pte_pfn(pte));
+       sync_icache_dcache(pte);
        set_pte_at(mm, addr, ptep, pte);
 
        if (PageAnon(new))
@@ -182,7 +183,6 @@ static void remove_migration_pte(struct 
 
        /* No need to invalidate - it was non-present before */
        update_mmu_cache(vma, addr, pte);
-       lazy_mmu_prot_update(pte);
 
 out:
        pte_unmap_unlock(ptep, ptl);
Index: linux-2.6.23-rc1.test/mm/hugetlb.c
===================================================================
--- linux-2.6.23-rc1.test.orig/mm/hugetlb.c
+++ linux-2.6.23-rc1.test/mm/hugetlb.c
@@ -352,7 +352,6 @@ static void set_huge_ptep_writable(struc
        entry = pte_mkwrite(pte_mkdirty(*ptep));
        if (ptep_set_access_flags(vma, address, ptep, entry, 1)) {
                update_mmu_cache(vma, address, entry);
-               lazy_mmu_prot_update(entry);
        }
 }
 
@@ -704,8 +703,8 @@ void hugetlb_change_protection(struct vm
                if (!pte_none(*ptep)) {
                        pte = huge_ptep_get_and_clear(mm, address, ptep);
                        pte = pte_mkhuge(pte_modify(pte, newprot));
+                       sync_icache_dcache(pte);
                        set_huge_pte_at(mm, address, ptep, pte);
-                       lazy_mmu_prot_update(pte);
                }
        }
        spin_unlock(&mm->page_table_lock);
Index: linux-2.6.23-rc1.test/arch/ia64/mm/init.c
===================================================================
--- linux-2.6.23-rc1.test.orig/arch/ia64/mm/init.c
+++ linux-2.6.23-rc1.test/arch/ia64/mm/init.c
@@ -53,16 +53,13 @@ EXPORT_SYMBOL(vmem_map);
 struct page *zero_page_memmap_ptr;     /* map entry for zero page */
 EXPORT_SYMBOL(zero_page_memmap_ptr);
 
-void
-lazy_mmu_prot_update (pte_t pte)
+void __sync_icache_dcache(pte_t pte)
 {
        unsigned long addr;
        struct page *page;
        unsigned long order;
 
-       if (!pte_exec(pte))
-               return;                         /* not an executable page... */
-
+       BUG_ON(!pte_exec(pte));
        page = pte_page(pte);
        addr = (unsigned long) page_address(page);
 
Index: linux-2.6.23-rc1.test/mm/mprotect.c
===================================================================
--- linux-2.6.23-rc1.test.orig/mm/mprotect.c
+++ linux-2.6.23-rc1.test/mm/mprotect.c
@@ -52,8 +52,8 @@ static void change_pte_range(struct mm_s
                         */
                        if (dirty_accountable && pte_dirty(ptent))
                                ptent = pte_mkwrite(ptent);
+                       sync_icache_dcache(ptent);
                        set_pte_at(mm, addr, pte, ptent);
-                       lazy_mmu_prot_update(ptent);
 #ifdef CONFIG_MIGRATION
                } else if (!pte_file(oldpte)) {
                        swp_entry_t entry = pte_to_swp_entry(oldpte);
Index: linux-2.6.23-rc1.test/mm/rmap.c
===================================================================
--- linux-2.6.23-rc1.test.orig/mm/rmap.c
+++ linux-2.6.23-rc1.test/mm/rmap.c
@@ -436,7 +436,6 @@ static int page_mkclean_one(struct page 
                entry = pte_wrprotect(entry);
                entry = pte_mkclean(entry);
                set_pte_at(mm, address, pte, entry);
-               lazy_mmu_prot_update(entry);
                ret = 1;
        }
 

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