From 7e01c949989b984c074469e04ab99c47367c7187 Mon Sep 17 00:00:00 2001 From: Paul Mundt Date: Fri, 4 Dec 2009 15:14:52 +0900 Subject: sh: Partial revert of copy/clear_user_highpage() optimizations. These still require more testing, so revert them for now. We keep the off-by-1 in the fixmap colouring and drop the rest. Signed-off-by: Paul Mundt --- arch/sh/mm/cache.c | 66 +++++++++++------------------------------------------- 1 file changed, 13 insertions(+), 53 deletions(-) (limited to 'arch') diff --git a/arch/sh/mm/cache.c b/arch/sh/mm/cache.c index 997c7e42b1e1..e9415d3ea94a 100644 --- a/arch/sh/mm/cache.c +++ b/arch/sh/mm/cache.c @@ -46,18 +46,6 @@ static inline void cacheop_on_each_cpu(void (*func) (void *info), void *info, preempt_enable(); } -/* - * copy_to_user_page - * @vma: vm_area_struct holding the pages - * @page: struct page - * @vaddr: user space address - * @dst: address of page in kernel space (possibly from kmap) - * @src: source address in kernel logical memory - * @len: length of data in bytes (may be less than PAGE_SIZE) - * - * Copy data into the address space of a process other than the current - * process (eg for ptrace). - */ void copy_to_user_page(struct vm_area_struct *vma, struct page *page, unsigned long vaddr, void *dst, const void *src, unsigned long len) @@ -93,49 +81,28 @@ void copy_from_user_page(struct vm_area_struct *vma, struct page *page, } } -/* - * copy_user_highpage - * @to: destination page - * @from: source page - * @vaddr: address of pages in user address space - * @vma: vm_area_struct holding the pages - * - * This is used in COW implementation to copy data from page @from to - * page @to. @from was previousl mapped at @vaddr, and @to will be. - * As this is used only in the COW implementation, this means that the - * source is unmodified, and so we don't have to worry about cache - * aliasing on that side. - */ -#ifdef CONFIG_HIGHMEM -/* - * If we ever have a real highmem system, this code will need fixing - * (as will clear_user/clear_user_highmem), because the kmap potentitally - * creates another alias risk. - */ -#error This code is broken with real HIGHMEM -#endif void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr, struct vm_area_struct *vma) { void *vfrom, *vto; vto = kmap_atomic(to, KM_USER1); - vfrom = kmap_atomic(from, KM_USER0); - - if (pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK)) - __flush_invalidate_region(vto, PAGE_SIZE); if (boot_cpu_data.dcache.n_aliases && page_mapped(from) && !test_bit(PG_dcache_dirty, &from->flags)) { - void *vto_coloured = kmap_coherent(to, vaddr); - copy_page(vto_coloured, vfrom); - kunmap_coherent(vto_coloured); - } else + vfrom = kmap_coherent(from, vaddr); copy_page(vto, vfrom); + kunmap_coherent(vfrom); + } else { + vfrom = kmap_atomic(from, KM_USER0); + copy_page(vto, vfrom); + kunmap_atomic(vfrom, KM_USER0); + } - kunmap_atomic(vfrom, KM_USER0); - kunmap_atomic(vto, KM_USER1); + if (pages_do_alias((unsigned long)vto, vaddr & PAGE_MASK)) + __flush_purge_region(vto, PAGE_SIZE); + kunmap_atomic(vto, KM_USER1); /* Make sure this page is cleared on other CPU's too before using it */ smp_wmb(); } @@ -145,17 +112,10 @@ void clear_user_highpage(struct page *page, unsigned long vaddr) { void *kaddr = kmap_atomic(page, KM_USER0); - if (pages_do_alias((unsigned long)kaddr, vaddr & PAGE_MASK)) { - void *vto; + clear_page(kaddr); - /* Kernel alias may have modified data in the cache. */ - __flush_invalidate_region(kaddr, PAGE_SIZE); - - vto = kmap_coherent(page, vaddr); - clear_page(vto); - kunmap_coherent(vto); - } else - clear_page(kaddr); + if (pages_do_alias((unsigned long)kaddr, vaddr & PAGE_MASK)) + __flush_purge_region(kaddr, PAGE_SIZE); kunmap_atomic(kaddr, KM_USER0); } -- cgit v1.2.3