From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753091AbYLRUCy (ORCPT ); Thu, 18 Dec 2008 15:02:54 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752277AbYLRUBr (ORCPT ); Thu, 18 Dec 2008 15:01:47 -0500 Received: from mga03.intel.com ([143.182.124.21]:27028 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752166AbYLRUBp (ORCPT ); Thu, 18 Dec 2008 15:01:45 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.36,244,1228118400"; d="scan'208";a="91793682" Message-Id: <20081218194617.408164000@intel.com> References: <20081218194126.963894000@intel.com> User-Agent: quilt/0.46-1 Date: Thu, 18 Dec 2008 11:41:29 -0800 From: venkatesh.pallipadi@intel.com To: mingo@elte.hu, tglx@linutronix.de, hpa@zytor.com, akpm@linux-foundation.org, npiggin@suse.de, hugh@veritas.com Cc: arjan@infradead.org, jbarnes@virtuousgeek.org, rdreier@cisco.com, jeremy@goop.org, linux-kernel@vger.kernel.org, Venkatesh Pallipadi , Suresh Siddha Subject: [patch 3/7] x86 PAT: hooks in generic vm code to help archs to track pfnmap regions - v3 Content-Disposition: inline; filename=generic_pfn_range_tracking.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Introduce generic hooks in remap_pfn_range and vm_insert_pfn and corresponding copy and free routines with reserve and free tracking. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha --- include/linux/mm.h | 6 ++++ mm/memory.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 81 insertions(+), 1 deletion(-) Index: linux-2.6/mm/memory.c =================================================================== --- linux-2.6.orig/mm/memory.c 2008-12-18 10:10:50.000000000 -0800 +++ linux-2.6/mm/memory.c 2008-12-18 10:11:23.000000000 -0800 @@ -99,6 +99,50 @@ int randomize_va_space __read_mostly = 2; #endif +#ifndef track_pfn_vma_new +/* + * Interface that can be used by architecture code to keep track of + * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn) + * + * track_pfn_vma_new is called when a _new_ pfn mapping is being established + * for physical range indicated by pfn and size. + */ +int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot, + unsigned long pfn, unsigned long size) +{ + return 0; +} +#endif + +#ifndef track_pfn_vma_copy +/* + * Interface that can be used by architecture code to keep track of + * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn) + * + * track_pfn_vma_copy is called when vma that is covering the pfnmap gets + * copied through copy_page_range(). + */ +int track_pfn_vma_copy(struct vm_area_struct *vma) +{ + return 0; +} +#endif + +#ifndef untrack_pfn_vma +/* + * Interface that can be used by architecture code to keep track of + * memory type of pfn mappings (remap_pfn_range, vm_insert_pfn) + * + * untrack_pfn_vma is called while unmapping a pfnmap for a region. + * untrack can be called for a specific region indicated by pfn and size or + * can be for the entire vma (in which case size can be zero). + */ +void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn, + unsigned long size) +{ +} +#endif + static int __init disable_randmaps(char *s) { randomize_va_space = 0; @@ -669,6 +713,16 @@ int copy_page_range(struct mm_struct *ds if (is_vm_hugetlb_page(vma)) return copy_hugetlb_page_range(dst_mm, src_mm, vma); + if (is_pfn_mapping(vma)) { + /* + * We do not free on error cases below as remove_vma + * gets called on error from higher level routine + */ + ret = track_pfn_vma_copy(vma); + if (ret) + return ret; + } + /* * We need to invalidate the secondary MMU mappings only when * there could be a permission downgrade on the ptes of the @@ -915,6 +969,9 @@ unsigned long unmap_vmas(struct mmu_gath if (vma->vm_flags & VM_ACCOUNT) *nr_accounted += (end - start) >> PAGE_SHIFT; + if (is_pfn_mapping(vma)) + untrack_pfn_vma(vma, 0, 0); + while (start != end) { if (!tlb_start_valid) { tlb_start = start; @@ -1473,6 +1530,7 @@ out: int vm_insert_pfn(struct vm_area_struct *vma, unsigned long addr, unsigned long pfn) { + int ret; /* * Technically, architectures with pte_special can avoid all these * restrictions (same for remap_pfn_range). However we would like @@ -1487,7 +1545,15 @@ int vm_insert_pfn(struct vm_area_struct if (addr < vma->vm_start || addr >= vma->vm_end) return -EFAULT; - return insert_pfn(vma, addr, pfn, vma->vm_page_prot); + if (track_pfn_vma_new(vma, vma->vm_page_prot, pfn, PAGE_SIZE)) + return -EINVAL; + + ret = insert_pfn(vma, addr, pfn, vma->vm_page_prot); + + if (ret) + untrack_pfn_vma(vma, pfn, PAGE_SIZE); + + return ret; } EXPORT_SYMBOL(vm_insert_pfn); @@ -1625,6 +1691,10 @@ int remap_pfn_range(struct vm_area_struc vma->vm_flags |= VM_IO | VM_RESERVED | VM_PFNMAP; + err = track_pfn_vma_new(vma, prot, pfn, PAGE_ALIGN(size)); + if (err) + return -EINVAL; + BUG_ON(addr >= end); pfn -= addr >> PAGE_SHIFT; pgd = pgd_offset(mm, addr); @@ -1636,6 +1706,10 @@ int remap_pfn_range(struct vm_area_struc if (err) break; } while (pgd++, addr = next, addr != end); + + if (err) + untrack_pfn_vma(vma, pfn, PAGE_ALIGN(size)); + return err; } EXPORT_SYMBOL(remap_pfn_range); Index: linux-2.6/include/linux/mm.h =================================================================== --- linux-2.6.orig/include/linux/mm.h 2008-12-18 10:10:50.000000000 -0800 +++ linux-2.6/include/linux/mm.h 2008-12-18 10:11:23.000000000 -0800 @@ -155,6 +155,12 @@ static inline int is_pfn_mapping(struct return (vma->vm_flags & VM_PFNMAP); } +extern int track_pfn_vma_new(struct vm_area_struct *vma, pgprot_t prot, + unsigned long pfn, unsigned long size); +extern int track_pfn_vma_copy(struct vm_area_struct *vma); +extern void untrack_pfn_vma(struct vm_area_struct *vma, unsigned long pfn, + unsigned long size); + /* * vm_fault is filled by the the pagefault handler and passed to the vma's * ->fault function. The vma's ->fault is responsible for returning a bitmask --