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author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-10-31 16:32:19 +0000 |
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committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-11-27 23:53:48 +0000 |
commit | 303c6443659bc1dc911356f5de149f48ff1d97b8 (patch) | |
tree | 75da0aef28ec8e843cdeb24c96349bdf812e2740 /arch/arm/mm/copypage-v6.c | |
parent | 063b0a4207e43acbeff3d4b09f43e750e0212b48 (diff) | |
download | lwn-303c6443659bc1dc911356f5de149f48ff1d97b8.tar.gz lwn-303c6443659bc1dc911356f5de149f48ff1d97b8.zip |
[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 <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm/copypage-v6.c')
-rw-r--r-- | arch/arm/mm/copypage-v6.c | 23 |
1 files changed, 9 insertions, 14 deletions
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; } |