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xtensa: implement clear_user_highpage and copy_user_highpage

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Existing clear_user_page and copy_user_page cannot be used with highmem
because they calculate physical page address from its virtual address
and do it incorrectly in case of high memory page mapped with
kmap_atomic. Also kmap is not needed, as most likely userspace mapping
color would be different from the kmapped color.

Provide clear_user_highpage and copy_user_highpage functions that
determine if temporary mapping is needed for the pages. Move most of the
logic of the former clear_user_page and copy_user_page to
xtensa/mm/cache.c only leaving temporary mapping setup, invalidation and
clearing/copying in the xtensa/mm/misc.S. Rename these functions to
clear_page_alias and copy_page_alias.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
This commit is contained in:
Max Filippov
2014-07-21 18:54:11 +04:00
parent 7128039fe2
commit a91902db29
4 changed files with 127 additions and 66 deletions
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12
arch/xtensa/include/asm/page.h
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@@ -134,6 +134,7 @@ static inline __attribute_const__ int get_order(unsigned long size)
#endif
struct page;
struct vm_area_struct;
extern void clear_page(void *page);
extern void copy_page(void *to, void *from);
@@ -143,8 +144,15 @@ extern void copy_page(void *to, void *from);
*/
#if DCACHE_WAY_SIZE > PAGE_SIZE
extern void clear_user_page(void*, unsigned long, struct page*);
extern void copy_user_page(void*, void*, unsigned long, struct page*);
extern void clear_page_alias(void *vaddr, unsigned long paddr);
extern void copy_page_alias(void *to, void *from,
unsigned long to_paddr, unsigned long from_paddr);
#define clear_user_highpage clear_user_highpage
void clear_user_highpage(struct page *page, unsigned long vaddr);
#define __HAVE_ARCH_COPY_USER_HIGHPAGE
void copy_user_highpage(struct page *to, struct page *from,
unsigned long vaddr, struct vm_area_struct *vma);
#else
# define clear_user_page(page, vaddr, pg) clear_page(page)
# define copy_user_page(to, from, vaddr, pg) copy_page(to, from)