patch-2_6_7-vs1_9_1_12

[linux-2.6.git] / arch / parisc / kernel / cache.c

diff --git a/arch/parisc/kernel/cache.c b/arch/parisc/kernel/cache.c
index 27ae25f..9fc0614 100644 (file)
--- a/arch/parisc/kernel/cache.c
+++ b/arch/parisc/kernel/cache.c
@@ -17,6 +17,7 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/seq_file.h>
+#include <linux/pagemap.h>
 
 #include <asm/pdc.h>
 #include <asm/cache.h>
@@ -230,68 +231,45 @@ void disable_sr_hashing(void)
 void __flush_dcache_page(struct page *page)
 {
        struct address_space *mapping = page_mapping(page);
-       struct mm_struct *mm = current->active_mm;
-       struct list_head *l;
+       struct vm_area_struct *mpnt = NULL;
+       struct prio_tree_iter iter;
+       unsigned long offset;
+       unsigned long addr;
+       pgoff_t pgoff;
 
        flush_kernel_dcache_page(page_address(page));
 
        if (!mapping)
                return;
-       /* check shared list first if it's not empty...it's usually
-        * the shortest */
-       list_for_each(l, &mapping->i_mmap_shared) {
-               struct vm_area_struct *mpnt;
-               unsigned long off;
-
-               mpnt = list_entry(l, struct vm_area_struct, shared);
-
-               /*
-                * If this VMA is not in our MM, we can ignore it.
-                */
-               if (mpnt->vm_mm != mm)
-                       continue;
-
-               if (page->index < mpnt->vm_pgoff)
-                       continue;
-
-               off = page->index - mpnt->vm_pgoff;
-               if (off >= (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT)
-                       continue;
-
-               flush_cache_page(mpnt, mpnt->vm_start + (off << PAGE_SHIFT));
 
-               /* All user shared mappings should be equivalently mapped,
-                * so once we've flushed one we should be ok
-                */
-               return;
-       }
-
-       /* then check private mapping list for read only shared mappings
-        * which are flagged by VM_MAYSHARE */
-       list_for_each(l, &mapping->i_mmap) {
-               struct vm_area_struct *mpnt;
-               unsigned long off;
+       pgoff = page->index << (PAGE_CACHE_SHIFT - PAGE_SHIFT);
 
-               mpnt = list_entry(l, struct vm_area_struct, shared);
+       /* We have carefully arranged in arch_get_unmapped_area() that
+        * *any* mappings of a file are always congruently mapped (whether
+        * declared as MAP_PRIVATE or MAP_SHARED), so we only need
+        * to flush one address here for them all to become coherent */
 
+       flush_dcache_mmap_lock(mapping);
+       while ((mpnt = vma_prio_tree_next(mpnt, &mapping->i_mmap,
+                                       &iter, pgoff, pgoff)) != NULL) {
+               offset = (pgoff - mpnt->vm_pgoff) << PAGE_SHIFT;
+               addr = mpnt->vm_start + offset;
 
-               if (mpnt->vm_mm != mm || !(mpnt->vm_flags & VM_MAYSHARE))
-                       continue;
-
-               if (page->index < mpnt->vm_pgoff)
-                       continue;
+               /* Flush instructions produce non access tlb misses.
+                * On PA, we nullify these instructions rather than
+                * taking a page fault if the pte doesn't exist.
+                * This is just for speed.  If the page translation
+                * isn't there, there's no point exciting the
+                * nadtlb handler into a nullification frenzy */
 
-               off = page->index - mpnt->vm_pgoff;
-               if (off >= (mpnt->vm_end - mpnt->vm_start) >> PAGE_SHIFT)
+               if (!translation_exists(mpnt, addr))
                        continue;
 
-               flush_cache_page(mpnt, mpnt->vm_start + (off << PAGE_SHIFT));
+               __flush_cache_page(mpnt, addr);
 
-               /* All user shared mappings should be equivalently mapped,
-                * so once we've flushed one we should be ok
-                */
                break;
        }
+       flush_dcache_mmap_unlock(mapping);
 }
 EXPORT_SYMBOL(__flush_dcache_page);