From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 8 Jul 2008 11:38:09 -0500 From: Jack Steiner Subject: [PATCH 1/2] - Unmap driver ptes Message-ID: <20080708163809.GA19366@sgi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: akpm@osdl.org Cc: linux-mm@kvack.org List-ID: Add 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. Signed-off-by: Jack Steiner --- include/linux/mm.h | 2 ++ mm/memory.c | 23 +++++++++++++++++++++++ 2 files changed, 25 insertions(+) Index: linux/include/linux/mm.h =================================================================== --- linux.orig/include/linux/mm.h 2008-07-07 12:22:17.809892803 -0500 +++ linux/include/linux/mm.h 2008-07-07 12:22:56.126695482 -0500 @@ -742,6 +742,8 @@ 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, Index: linux/mm/memory.c =================================================================== --- linux.orig/mm/memory.c 2008-07-07 12:22:18.357961503 -0500 +++ linux/mm/memory.c 2008-07-07 12:31:51.097688882 -0500 @@ -978,6 +978,29 @@ unsigned long zap_page_range(struct vm_a } EXPORT_SYMBOL_GPL(zap_page_range); +/** + * 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. */ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org