diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/linux/highmem.h |
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/linux/highmem.h')
-rw-r--r-- | include/linux/highmem.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/include/linux/highmem.h b/include/linux/highmem.h new file mode 100644 index 000000000000..2a7e6c65c882 --- /dev/null +++ b/include/linux/highmem.h @@ -0,0 +1,104 @@ +#ifndef _LINUX_HIGHMEM_H +#define _LINUX_HIGHMEM_H + +#include <linux/config.h> +#include <linux/fs.h> +#include <linux/mm.h> + +#include <asm/cacheflush.h> + +#ifdef CONFIG_HIGHMEM + +#include <asm/highmem.h> + +/* declarations for linux/mm/highmem.c */ +unsigned int nr_free_highpages(void); + +#else /* CONFIG_HIGHMEM */ + +static inline unsigned int nr_free_highpages(void) { return 0; } + +static inline void *kmap(struct page *page) +{ + might_sleep(); + return page_address(page); +} + +#define kunmap(page) do { (void) (page); } while (0) + +#define kmap_atomic(page, idx) page_address(page) +#define kunmap_atomic(addr, idx) do { } while (0) +#define kmap_atomic_to_page(ptr) virt_to_page(ptr) + +#endif /* CONFIG_HIGHMEM */ + +/* when CONFIG_HIGHMEM is not set these will be plain clear/copy_page */ +static inline void clear_user_highpage(struct page *page, unsigned long vaddr) +{ + void *addr = kmap_atomic(page, KM_USER0); + clear_user_page(addr, vaddr, page); + kunmap_atomic(addr, KM_USER0); + /* Make sure this page is cleared on other CPU's too before using it */ + smp_wmb(); +} + +#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE +static inline struct page * +alloc_zeroed_user_highpage(struct vm_area_struct *vma, unsigned long vaddr) +{ + struct page *page = alloc_page_vma(GFP_HIGHUSER, vma, vaddr); + + if (page) + clear_user_highpage(page, vaddr); + + return page; +} +#endif + +static inline void clear_highpage(struct page *page) +{ + void *kaddr = kmap_atomic(page, KM_USER0); + clear_page(kaddr); + kunmap_atomic(kaddr, KM_USER0); +} + +/* + * Same but also flushes aliased cache contents to RAM. + */ +static inline void memclear_highpage_flush(struct page *page, unsigned int offset, unsigned int size) +{ + void *kaddr; + + BUG_ON(offset + size > PAGE_SIZE); + + kaddr = kmap_atomic(page, KM_USER0); + memset((char *)kaddr + offset, 0, size); + flush_dcache_page(page); + kunmap_atomic(kaddr, KM_USER0); +} + +static inline void copy_user_highpage(struct page *to, struct page *from, unsigned long vaddr) +{ + char *vfrom, *vto; + + vfrom = kmap_atomic(from, KM_USER0); + vto = kmap_atomic(to, KM_USER1); + copy_user_page(vto, vfrom, vaddr, to); + kunmap_atomic(vfrom, KM_USER0); + kunmap_atomic(vto, KM_USER1); + /* Make sure this page is cleared on other CPU's too before using it */ + smp_wmb(); +} + +static inline void copy_highpage(struct page *to, struct page *from) +{ + char *vfrom, *vto; + + vfrom = kmap_atomic(from, KM_USER0); + vto = kmap_atomic(to, KM_USER1); + copy_page(vto, vfrom); + kunmap_atomic(vfrom, KM_USER0); + kunmap_atomic(vto, KM_USER1); +} + +#endif /* _LINUX_HIGHMEM_H */ |