diff options
| author | Jack Steiner <steiner@sgi.com> | 2008-07-29 22:33:53 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-30 09:41:47 -0700 |
| commit | c627f9cc046c7cd93b4525d89377fb409e170a18 (patch) | |
| tree | 851913d2ebd2946b577592fb410f750e6fdc943b | |
| parent | f718cd4add5aea9d379faff92f162571e356cc5f (diff) | |
| download | linux-c627f9cc046c7cd93b4525d89377fb409e170a18.tar.bz2 | |
mm: add zap_vma_ptes(): a library function to unmap driver ptes
zap_vma_ptes() is intended to be used by drivers to unmap ptes assigned to the
driver private vmas. This interface is similar to zap_page_range() but is
less general & less likely to be abused.
Needed by the GRU driver.
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | include/linux/mm.h | 2 | ||||
| -rw-r--r-- | mm/memory.c | 23 |
2 files changed, 25 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 5e2c8af49998..335288bff1b7 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -744,6 +744,8 @@ struct zap_details { struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr, pte_t pte); +int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address, + unsigned long size); unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address, unsigned long size, struct zap_details *); unsigned long unmap_vmas(struct mmu_gather **tlb, diff --git a/mm/memory.c b/mm/memory.c index 67f0ab9077d9..6793b9c68107 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -994,6 +994,29 @@ unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address, return end; } +/** + * zap_vma_ptes - remove ptes mapping the vma + * @vma: vm_area_struct holding ptes to be zapped + * @address: starting address of pages to zap + * @size: number of bytes to zap + * + * This function only unmaps ptes assigned to VM_PFNMAP vmas. + * + * The entire address range must be fully contained within the vma. + * + * Returns 0 if successful. + */ +int zap_vma_ptes(struct vm_area_struct *vma, unsigned long address, + unsigned long size) +{ + if (address < vma->vm_start || address + size > vma->vm_end || + !(vma->vm_flags & VM_PFNMAP)) + return -1; + zap_page_range(vma, address, size, NULL); + return 0; +} +EXPORT_SYMBOL_GPL(zap_vma_ptes); + /* * Do a quick page-table lookup for a single page. */ |