kernel-ark/include/linux/highmem.h

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#ifndef _LINUX_HIGHMEM_H
#define _LINUX_HIGHMEM_H
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#ifndef ARCH_HAS_FLUSH_ANON_PAGE
static inline void flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vmaddr)
{
}
#endif
#ifndef ARCH_HAS_FLUSH_KERNEL_DCACHE_PAGE
static inline void flush_kernel_dcache_page(struct page *page)
{
}
#endif
#ifdef CONFIG_HIGHMEM
#include <asm/highmem.h>
/* declarations for linux/mm/highmem.c */
unsigned int nr_free_highpages(void);
extern unsigned long totalhigh_pages;
void kmap_flush_unused(void);
#else /* CONFIG_HIGHMEM */
static inline unsigned int nr_free_highpages(void) { return 0; }
#define totalhigh_pages 0
#ifndef ARCH_HAS_KMAP
static inline void *kmap(struct page *page)
{
might_sleep();
return page_address(page);
}
#define kunmap(page) do { (void) (page); } while (0)
#include <asm/kmap_types.h>
static inline void *kmap_atomic(struct page *page, enum km_type idx)
{
pagefault_disable();
return page_address(page);
}
#define kmap_atomic_prot(page, idx, prot) kmap_atomic(page, idx)
#define kunmap_atomic(addr, idx) do { pagefault_enable(); } while (0)
#define kmap_atomic_pfn(pfn, idx) kmap_atomic(pfn_to_page(pfn), (idx))
#define kmap_atomic_to_page(ptr) virt_to_page(ptr)
#define kmap_flush_unused() do {} while(0)
#endif
#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
Add __GFP_MOVABLE for callers to flag allocations from high memory that may be migrated It is often known at allocation time whether a page may be migrated or not. This patch adds a flag called __GFP_MOVABLE and a new mask called GFP_HIGH_MOVABLE. Allocations using the __GFP_MOVABLE can be either migrated using the page migration mechanism or reclaimed by syncing with backing storage and discarding. An API function very similar to alloc_zeroed_user_highpage() is added for __GFP_MOVABLE allocations called alloc_zeroed_user_highpage_movable(). The flags used by alloc_zeroed_user_highpage() are not changed because it would change the semantics of an existing API. After this patch is applied there are no in-kernel users of alloc_zeroed_user_highpage() so it probably should be marked deprecated if this patch is merged. Note that this patch includes a minor cleanup to the use of __GFP_ZERO in shmem.c to keep all flag modifications to inode->mapping in the shmem_dir_alloc() helper function. This clean-up suggestion is courtesy of Hugh Dickens. Additional credit goes to Christoph Lameter and Linus Torvalds for shaping the concept. Credit to Hugh Dickens for catching issues with shmem swap vector and ramfs allocations. [akpm@linux-foundation.org: build fix] [hugh@veritas.com: __GFP_ZERO cleanup] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 11:03:05 +00:00
/**
* __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags
* @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE
* @vma: The VMA the page is to be allocated for
* @vaddr: The virtual address the page will be inserted into
*
* This function will allocate a page for a VMA but the caller is expected
* to specify via movableflags whether the page will be movable in the
* future or not
*
* An architecture may override this function by defining
* __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own
* implementation.
*/
static inline struct page *
Add __GFP_MOVABLE for callers to flag allocations from high memory that may be migrated It is often known at allocation time whether a page may be migrated or not. This patch adds a flag called __GFP_MOVABLE and a new mask called GFP_HIGH_MOVABLE. Allocations using the __GFP_MOVABLE can be either migrated using the page migration mechanism or reclaimed by syncing with backing storage and discarding. An API function very similar to alloc_zeroed_user_highpage() is added for __GFP_MOVABLE allocations called alloc_zeroed_user_highpage_movable(). The flags used by alloc_zeroed_user_highpage() are not changed because it would change the semantics of an existing API. After this patch is applied there are no in-kernel users of alloc_zeroed_user_highpage() so it probably should be marked deprecated if this patch is merged. Note that this patch includes a minor cleanup to the use of __GFP_ZERO in shmem.c to keep all flag modifications to inode->mapping in the shmem_dir_alloc() helper function. This clean-up suggestion is courtesy of Hugh Dickens. Additional credit goes to Christoph Lameter and Linus Torvalds for shaping the concept. Credit to Hugh Dickens for catching issues with shmem swap vector and ramfs allocations. [akpm@linux-foundation.org: build fix] [hugh@veritas.com: __GFP_ZERO cleanup] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 11:03:05 +00:00
__alloc_zeroed_user_highpage(gfp_t movableflags,
struct vm_area_struct *vma,
unsigned long vaddr)
{
Add __GFP_MOVABLE for callers to flag allocations from high memory that may be migrated It is often known at allocation time whether a page may be migrated or not. This patch adds a flag called __GFP_MOVABLE and a new mask called GFP_HIGH_MOVABLE. Allocations using the __GFP_MOVABLE can be either migrated using the page migration mechanism or reclaimed by syncing with backing storage and discarding. An API function very similar to alloc_zeroed_user_highpage() is added for __GFP_MOVABLE allocations called alloc_zeroed_user_highpage_movable(). The flags used by alloc_zeroed_user_highpage() are not changed because it would change the semantics of an existing API. After this patch is applied there are no in-kernel users of alloc_zeroed_user_highpage() so it probably should be marked deprecated if this patch is merged. Note that this patch includes a minor cleanup to the use of __GFP_ZERO in shmem.c to keep all flag modifications to inode->mapping in the shmem_dir_alloc() helper function. This clean-up suggestion is courtesy of Hugh Dickens. Additional credit goes to Christoph Lameter and Linus Torvalds for shaping the concept. Credit to Hugh Dickens for catching issues with shmem swap vector and ramfs allocations. [akpm@linux-foundation.org: build fix] [hugh@veritas.com: __GFP_ZERO cleanup] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 11:03:05 +00:00
struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags,
vma, vaddr);
if (page)
clear_user_highpage(page, vaddr);
return page;
}
#endif
Add __GFP_MOVABLE for callers to flag allocations from high memory that may be migrated It is often known at allocation time whether a page may be migrated or not. This patch adds a flag called __GFP_MOVABLE and a new mask called GFP_HIGH_MOVABLE. Allocations using the __GFP_MOVABLE can be either migrated using the page migration mechanism or reclaimed by syncing with backing storage and discarding. An API function very similar to alloc_zeroed_user_highpage() is added for __GFP_MOVABLE allocations called alloc_zeroed_user_highpage_movable(). The flags used by alloc_zeroed_user_highpage() are not changed because it would change the semantics of an existing API. After this patch is applied there are no in-kernel users of alloc_zeroed_user_highpage() so it probably should be marked deprecated if this patch is merged. Note that this patch includes a minor cleanup to the use of __GFP_ZERO in shmem.c to keep all flag modifications to inode->mapping in the shmem_dir_alloc() helper function. This clean-up suggestion is courtesy of Hugh Dickens. Additional credit goes to Christoph Lameter and Linus Torvalds for shaping the concept. Credit to Hugh Dickens for catching issues with shmem swap vector and ramfs allocations. [akpm@linux-foundation.org: build fix] [hugh@veritas.com: __GFP_ZERO cleanup] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-17 11:03:05 +00:00
/**
* alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move
* @vma: The VMA the page is to be allocated for
* @vaddr: The virtual address the page will be inserted into
*
* This function will allocate a page for a VMA that the caller knows will
* be able to migrate in the future using move_pages() or reclaimed
*/
static inline struct page *
alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma,
unsigned long vaddr)
{
return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr);
}
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.
*
* This must be a macro because KM_USER0 and friends aren't defined if
* !CONFIG_HIGHMEM
*/
#define zero_user_page(page, offset, size, km_type) \
do { \
void *kaddr; \
\
BUG_ON((offset) + (size) > PAGE_SIZE); \
\
kaddr = kmap_atomic(page, km_type); \
memset((char *)kaddr + (offset), 0, (size)); \
flush_dcache_page(page); \
kunmap_atomic(kaddr, (km_type)); \
} while (0)
static inline void __deprecated memclear_highpage_flush(struct page *page,
unsigned int offset, unsigned int size)
{
zero_user_page(page, offset, size, KM_USER0);
}
#ifndef __HAVE_ARCH_COPY_USER_HIGHPAGE
static inline void copy_user_highpage(struct page *to, struct page *from,
unsigned long vaddr, struct vm_area_struct *vma)
{
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();
}
#endif
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 */