ARC: [mm] Assume pagecache page dirty by default

Similar to ARM/SH

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

3 files changed, 14 insertions, 7 deletions

diff --git a/arch/arc/include/asm/cacheflush.h b/arch/arc/include/asm/cacheflush.h
index 185dfd03dcdb..6abc4972bc93 100644
--- a/arch/arc/include/asm/cacheflush.h
+++ b/arch/arc/include/asm/cacheflush.h
@@ -81,6 +81,13 @@ void flush_anon_page(struct vm_area_struct *vma,
 #endif  /* CONFIG_ARC_CACHE_VIPT_ALIASING */
 
 /*
+ * A new pagecache page has PG_arch_1 clear - thus dcache dirty by default
+ * This works around some PIO based drivers which don't call flush_dcache_page
+ * to record that they dirtied the dcache
+ */
+#define PG_dc_clean     PG_arch_1
+
+/*
  * Simple wrapper over config option
  * Bootup code ensures that hardware matches kernel configuration
  */
diff --git a/arch/arc/mm/cache_arc700.c b/arch/arc/mm/cache_arc700.c
index 074658704d86..66c75ee16e50 100644
--- a/arch/arc/mm/cache_arc700.c
+++ b/arch/arc/mm/cache_arc700.c
@@ -512,7 +512,7 @@ void flush_dcache_page(struct page *page)
         struct address_space *mapping;
 
         if (!cache_is_vipt_aliasing()) {
-                set_bit(PG_arch_1, &page->flags);
+                clear_bit(PG_dc_clean, &page->flags);
                 return;
         }
 
@@ -526,7 +526,7 @@ void flush_dcache_page(struct page *page)
          * Make a note that K-mapping is dirty
          */
         if (!mapping_mapped(mapping)) {
-                set_bit(PG_arch_1, &page->flags);
+                clear_bit(PG_dc_clean, &page->flags);
         } else if (page_mapped(page)) {
 
                 /* kernel reading from page with U-mapping */
@@ -734,7 +734,7 @@ void copy_user_highpage(struct page *to, struct page *from,
          * non copied user pages (e.g. read faults which wire in pagecache page
          * directly).
          */
-        set_bit(PG_arch_1, &to->flags);
+        clear_bit(PG_dc_clean, &to->flags);
 
         /*
          * if SRC was already usermapped and non-congruent to kernel mapping
@@ -742,16 +742,16 @@ void copy_user_highpage(struct page *to, struct page *from,
          */
         if (clean_src_k_mappings) {
                 __flush_dcache_page(kfrom, kfrom);
-                clear_bit(PG_arch_1, &from->flags);
+                set_bit(PG_dc_clean, &from->flags);
         } else {
-                set_bit(PG_arch_1, &from->flags);
+                clear_bit(PG_dc_clean, &from->flags);
         }
 }
 
 void clear_user_page(void *to, unsigned long u_vaddr, struct page *page)
 {
         clear_page(to);
-        set_bit(PG_arch_1, &page->flags);
+        clear_bit(PG_dc_clean, &page->flags);
 }
 
 
diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c
index 1c91dbc8ddd8..d44ae33c2d1e 100644
--- a/arch/arc/mm/tlb.c
+++ b/arch/arc/mm/tlb.c
@@ -453,7 +453,7 @@ void update_mmu_cache(struct vm_area_struct *vma, unsigned long vaddr_unaligned,
         if ((vma->vm_flags & VM_EXEC) ||
              addr_not_cache_congruent(paddr, vaddr)) {
 
-                int dirty = test_and_clear_bit(PG_arch_1, &page->flags);
+                int dirty = !test_and_set_bit(PG_dc_clean, &page->flags);
                 if (dirty) {
                         /* wback + inv dcache lines */
                         __flush_dcache_page(paddr, paddr);