sh: Assume new page cache pages have dirty dcache lines.

This follows the ARM change c01778001a4f5ad9c62d882776235f3f31922fdd
("ARM: 6379/1: Assume new page cache pages have dirty D-cache") for the
same rationale:

    There are places in Linux where writes to newly allocated page
    cache pages happen without a subsequent call to flush_dcache_page()
    (several PIO drivers including USB HCD). This patch changes the
    meaning of PG_arch_1 to be PG_dcache_clean and always flush the
    D-cache for a newly mapped page in update_mmu_cache().

This addresses issues seen with executing binaries from MMC, in
addition to some of the other HCDs that don't explicitly do cache
management for their pipe-in buffers.

Requested-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 7 insertions, 7 deletions

diff --git a/arch/sh/mm/cache.c b/arch/sh/mm/cache.c
index ba401d137bb9..88d3dc3d30d5 100644
--- a/arch/sh/mm/cache.c
+++ b/arch/sh/mm/cache.c
@@ -60,14 +60,14 @@ void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
 		       unsigned long len)
 {
 	if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
-	    !test_bit(PG_dcache_dirty, &page->flags)) {
+	    test_bit(PG_dcache_clean, &page->flags)) {
 		void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 		memcpy(vto, src, len);
 		kunmap_coherent(vto);
 	} else {
 		memcpy(dst, src, len);
 		if (boot_cpu_data.dcache.n_aliases)
-			set_bit(PG_dcache_dirty, &page->flags);
+			clear_bit(PG_dcache_clean, &page->flags);
 	}
 
 	if (vma->vm_flags & VM_EXEC)
@@ -79,14 +79,14 @@ void copy_from_user_page(struct vm_area_struct *vma, struct page *page,
 			 unsigned long len)
 {
 	if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
-	    !test_bit(PG_dcache_dirty, &page->flags)) {
+	    test_bit(PG_dcache_clean, &page->flags)) {
 		void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);
 		memcpy(dst, vfrom, len);
 		kunmap_coherent(vfrom);
 	} else {
 		memcpy(dst, src, len);
 		if (boot_cpu_data.dcache.n_aliases)
-			set_bit(PG_dcache_dirty, &page->flags);
+			clear_bit(PG_dcache_clean, &page->flags);
 	}
 }
 
@@ -98,7 +98,7 @@ void copy_user_highpage(struct page *to, struct page *from,
 	vto = kmap_atomic(to, KM_USER1);
 
 	if (boot_cpu_data.dcache.n_aliases && page_mapped(from) &&
-	    !test_bit(PG_dcache_dirty, &from->flags)) {
+	    test_bit(PG_dcache_clean, &from->flags)) {
 		vfrom = kmap_coherent(from, vaddr);
 		copy_page(vto, vfrom);
 		kunmap_coherent(vfrom);
@@ -141,7 +141,7 @@ void __update_cache(struct vm_area_struct *vma,
 
 	page = pfn_to_page(pfn);
 	if (pfn_valid(pfn)) {
-		int dirty = test_and_clear_bit(PG_dcache_dirty, &page->flags);
+		int dirty = !test_and_set_bit(PG_dcache_clean, &page->flags);
 		if (dirty)
 			__flush_purge_region(page_address(page), PAGE_SIZE);
 	}
@@ -153,7 +153,7 @@ void __flush_anon_page(struct page *page, unsigned long vmaddr)
 
 	if (pages_do_alias(addr, vmaddr)) {
 		if (boot_cpu_data.dcache.n_aliases && page_mapped(page) &&
-		    !test_bit(PG_dcache_dirty, &page->flags)) {
+		    test_bit(PG_dcache_clean, &page->flags)) {
 			void *kaddr;
 
 			kaddr = kmap_coherent(page, vmaddr);