1 files changed, 8 insertions, 29 deletions

diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c
index 88611c3a421a..e4193e3adc7f 100644
--- a/arch/arm64/mm/flush.c
+++ b/arch/arm64/mm/flush.c
@@ -70,23 +70,16 @@ void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
 #endif
 }
 
-void __flush_dcache_page(struct page *page)
-{
-        __flush_dcache_area(page_address(page), PAGE_SIZE);
-}
-
 void __sync_icache_dcache(pte_t pte, unsigned long addr)
 {
-        unsigned long pfn;
-        struct page *page;
+        struct page *page = pte_page(pte);
 
-        pfn = pte_pfn(pte);
-        if (!pfn_valid(pfn))
+        /* no flushing needed for anonymous pages */
+        if (!page_mapping(page))
                 return;
 
-        page = pfn_to_page(pfn);
         if (!test_and_set_bit(PG_dcache_clean, &page->flags)) {
-                __flush_dcache_page(page);
+                __flush_dcache_area(page_address(page), PAGE_SIZE);
                 __flush_icache_all();
         } else if (icache_is_aivivt()) {
                 __flush_icache_all();
@@ -94,28 +87,14 @@ void __sync_icache_dcache(pte_t pte, unsigned long addr)
 }
 
 /*
- * Ensure cache coherency between kernel mapping and userspace mapping of this
- * page.
+ * This function is called when a page has been modified by the kernel. Mark
+ * it as dirty for later flushing when mapped in user space (if executable,
+ * see __sync_icache_dcache).
  */
 void flush_dcache_page(struct page *page)
 {
-        struct address_space *mapping;
-
-        /*
-         * The zero page is never written to, so never has any dirty cache
-         * lines, and therefore never needs to be flushed.
-         */
-        if (page == ZERO_PAGE(0))
-                return;
-
-        mapping = page_mapping(page);
-        if (mapping && mapping_mapped(mapping)) {
-                __flush_dcache_page(page);
-                __flush_icache_all();
-                set_bit(PG_dcache_clean, &page->flags);
-        } else {
+        if (test_bit(PG_dcache_clean, &page->flags))
                 clear_bit(PG_dcache_clean, &page->flags);
-        }
 }
 EXPORT_SYMBOL(flush_dcache_page);