Commit 9a74b3eb authored by Ralf Baechle's avatar Ralf Baechle
Browse files

[MIPS] Fix buggy invocations of kmap_coherent() 



kmap_coherent will only work correctly if the page it is called on is
not marked dirty.  If it's dirty the kernel address of the page should
be used instead of a temporary mapping.

Signed-off-by: default avatarRalf Baechle <ralf@linux-mips.org>
parent c42d95d6

arch/mips/mm/cache.c

+10 −5
Original line number Diff line number Diff line
@@ -92,12 +92,17 @@ EXPORT_SYMBOL(__flush_dcache_page); 


void __flush_anon_page(struct page *page, unsigned long vmaddr)

{

	if (pages_do_alias((unsigned long)page_address(page), vmaddr)) {

	unsigned long addr = (unsigned long) page_address(page);



	if (pages_do_alias(addr, vmaddr)) {

		if (page_mapped(page) && !Page_dcache_dirty(page)) {

			void *kaddr;



			kaddr = kmap_coherent(page, vmaddr);

			flush_data_cache_page((unsigned long)kaddr);

			kunmap_coherent();

		} else

			flush_data_cache_page(addr);

	}

}

arch/mips/mm/init.c

+6 −3
Original line number Diff line number Diff line
@@ -211,7 +211,8 @@ void copy_user_highpage(struct page *to, struct page *from, 
	void *vfrom, *vto;



	vto = kmap_atomic(to, KM_USER1);

	if (cpu_has_dc_aliases && page_mapped(from)) {

	if (cpu_has_dc_aliases &&

	    page_mapped(from) && !Page_dcache_dirty(from)) {

		vfrom = kmap_coherent(from, vaddr);

		copy_page(vto, vfrom);

		kunmap_coherent();
@@ -234,7 +235,8 @@ void copy_to_user_page(struct vm_area_struct *vma, 
	struct page *page, unsigned long vaddr, void *dst, const void *src,

	unsigned long len)

{

	if (cpu_has_dc_aliases && page_mapped(page)) {

	if (cpu_has_dc_aliases &&

	    page_mapped(page) && !Page_dcache_dirty(page)) {

		void *vto = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);

		memcpy(vto, src, len);

		kunmap_coherent();
@@ -253,7 +255,8 @@ void copy_from_user_page(struct vm_area_struct *vma, 
	struct page *page, unsigned long vaddr, void *dst, const void *src,

	unsigned long len)

{

	if (cpu_has_dc_aliases && page_mapped(page)) {

	if (cpu_has_dc_aliases &&

	    page_mapped(page) && !Page_dcache_dirty(page)) {

		void *vfrom = kmap_coherent(page, vaddr) + (vaddr & ~PAGE_MASK);

		memcpy(dst, vfrom, len);

		kunmap_coherent();