From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752307AbYLRUCV (ORCPT ); Thu, 18 Dec 2008 15:02:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752188AbYLRUBq (ORCPT ); Thu, 18 Dec 2008 15:01:46 -0500 Received: from mga09.intel.com ([134.134.136.24]:27331 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750746AbYLRUBp (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="475173569" Message-Id: <20081218194617.247280000@intel.com> References: <20081218194126.963894000@intel.com> User-Agent: quilt/0.46-1 Date: Thu, 18 Dec 2008 11:41:28 -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 2/7] x86 PAT: Add follow_pfnmp_pte routine to help tracking pfnmap pages - v3 Content-Disposition: inline; filename=follow_pfn.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a generic interface to follow pfn in a pfnmap vma range. This is used by one of the subsequent x86 PAT related patch to keep track of memory types for vma regions across vma copy and free. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Suresh Siddha --- include/linux/mm.h | 3 +++ mm/memory.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+) Index: linux-2.6/include/linux/mm.h =================================================================== --- linux-2.6.orig/include/linux/mm.h 2008-11-25 13:56:46.000000000 -0800 +++ linux-2.6/include/linux/mm.h 2008-11-25 14:20:23.000000000 -0800 @@ -1223,6 +1223,9 @@ struct page *follow_page(struct vm_area_ #define FOLL_GET 0x04 /* do get_page on page */ #define FOLL_ANON 0x08 /* give ZERO_PAGE if no pgtable */ +int follow_pfnmap_pte(struct vm_area_struct *vma, + unsigned long address, pte_t *ret_ptep); + typedef int (*pte_fn_t)(pte_t *pte, pgtable_t token, unsigned long addr, void *data); extern int apply_to_page_range(struct mm_struct *mm, unsigned long address, Index: linux-2.6/mm/memory.c =================================================================== --- linux-2.6.orig/mm/memory.c 2008-11-25 14:07:42.000000000 -0800 +++ linux-2.6/mm/memory.c 2008-11-25 14:18:35.000000000 -0800 @@ -1111,6 +1111,49 @@ no_page_table: return page; } +int follow_pfnmap_pte(struct vm_area_struct *vma, unsigned long address, + pte_t *ret_ptep) +{ + pgd_t *pgd; + pud_t *pud; + pmd_t *pmd; + pte_t *ptep, pte; + spinlock_t *ptl; + struct page *page; + struct mm_struct *mm = vma->vm_mm; + + if (!is_pfn_mapping(vma)) + goto err; + + page = NULL; + pgd = pgd_offset(mm, address); + if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) + goto err; + + pud = pud_offset(pgd, address); + if (pud_none(*pud) || unlikely(pud_bad(*pud))) + goto err; + + pmd = pmd_offset(pud, address); + if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd))) + goto err; + + ptep = pte_offset_map_lock(mm, pmd, address, &ptl); + + pte = *ptep; + if (!pte_present(pte)) + goto err_unlock; + + *ret_ptep = pte; + pte_unmap_unlock(ptep, ptl); + return 0; + +err_unlock: + pte_unmap_unlock(ptep, ptl); +err: + return -EINVAL; +} + /* Can we do the FOLL_ANON optimization? */ static inline int use_zero_page(struct vm_area_struct *vma) { --