From 303c6443659bc1dc911356f5de149f48ff1d97b8 Mon Sep 17 00:00:00 2001 From: Russell King Date: Fri, 31 Oct 2008 16:32:19 +0000 Subject: [ARM] clearpage: provide our own clear_user_highpage() For similar reasons as copy_user_page(), we want to avoid the additional kmap_atomic if it's unnecessary. Signed-off-by: Russell King --- arch/arm/mm/copypage-v6.c | 23 +++++++++-------------- 1 file changed, 9 insertions(+), 14 deletions(-) (limited to 'arch/arm/mm/copypage-v6.c') diff --git a/arch/arm/mm/copypage-v6.c b/arch/arm/mm/copypage-v6.c index 2ea75d0f5048..4127a7bddfe5 100644 --- a/arch/arm/mm/copypage-v6.c +++ b/arch/arm/mm/copypage-v6.c @@ -49,9 +49,11 @@ static void v6_copy_user_highpage_nonaliasing(struct page *to, * Clear the user page. No aliasing to deal with so we can just * attack the kernel's existing mapping of this page. */ -static void v6_clear_user_page_nonaliasing(void *kaddr, unsigned long vaddr) +static void v6_clear_user_highpage_nonaliasing(struct page *page, unsigned long vaddr) { + void *kaddr = kmap_atomic(page, KM_USER0); clear_page(kaddr); + kunmap_atomic(kaddr, KM_USER0); } /* @@ -107,20 +109,13 @@ static void v6_copy_user_highpage_aliasing(struct page *to, * so remap the kernel page into the same cache colour as the user * page. */ -static void v6_clear_user_page_aliasing(void *kaddr, unsigned long vaddr) +static void v6_clear_user_highpage_aliasing(struct page *page, unsigned long vaddr) { unsigned int offset = CACHE_COLOUR(vaddr); unsigned long to = to_address + (offset << PAGE_SHIFT); - /* - * Discard data in the kernel mapping for the new page - * FIXME: needs this MCRR to be supported. - */ - __asm__("mcrr p15, 0, %1, %0, c6 @ 0xec401f06" - : - : "r" (kaddr), - "r" ((unsigned long)kaddr + PAGE_SIZE - L1_CACHE_BYTES) - : "cc"); + /* FIXME: not highmem safe */ + discard_old_kernel_data(page_address(page)); /* * Now clear the page using the same cache colour as @@ -128,7 +123,7 @@ static void v6_clear_user_page_aliasing(void *kaddr, unsigned long vaddr) */ spin_lock(&v6_lock); - set_pte_ext(TOP_PTE(to_address) + offset, pfn_pte(__pa(kaddr) >> PAGE_SHIFT, PAGE_KERNEL), 0); + set_pte_ext(TOP_PTE(to_address) + offset, pfn_pte(page_to_pfn(page), PAGE_KERNEL), 0); flush_tlb_kernel_page(to); clear_page((void *)to); @@ -136,14 +131,14 @@ static void v6_clear_user_page_aliasing(void *kaddr, unsigned long vaddr) } struct cpu_user_fns v6_user_fns __initdata = { - .cpu_clear_user_page = v6_clear_user_page_nonaliasing, + .cpu_clear_user_highpage = v6_clear_user_highpage_nonaliasing, .cpu_copy_user_highpage = v6_copy_user_highpage_nonaliasing, }; static int __init v6_userpage_init(void) { if (cache_is_vipt_aliasing()) { - cpu_user.cpu_clear_user_page = v6_clear_user_page_aliasing; + cpu_user.cpu_clear_user_highpage = v6_clear_user_highpage_aliasing; cpu_user.cpu_copy_user_highpage = v6_copy_user_highpage_aliasing; } -- cgit v1.2.3-70-g09d2