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-rw-r--r--arch/arm64/mm/flush.c37
1 files changed, 8 insertions, 29 deletions
diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c
index 88611c3a421..e4193e3adc7 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);