From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oded Gabbay Subject: [PATCH 28/83] mm: Change timing of notification to IOMMUs about a page to be invalidated Date: Fri, 11 Jul 2014 00:53:26 +0300 Message-ID: <1405029208-6703-1-git-send-email-oded.gabbay@amd.com> Return-path: Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: David Airlie , Alex Deucher , Jerome Glisse , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, John Bridgman , Andrew Lewycky , Joerg Roedel , linux-mm , Oded Gabbay , Naoya Horiguchi , Joonsoo Kim , "Kirill A. Shutemov" , Hugh Dickins , Cyrill Gorcunov , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Jianyu Zhan List-Id: dri-devel@lists.freedesktop.org From: Andrew Lewycky This patch changes the location of the mmu_notifier_invalidate_page function call inside try_to_unmap_one. The mmu_notifier_invalidate_page function call tells the IOMMU that a pgae should be invalidated. The location is changed from after releasing the physical page to before releasing the physical page. This change should prevent the bug that would occur in the (rare) case where the GPU attempts to access a page while the CPU attempts to swap out that page (or discard it if it is not dirty). Signed-off-by: Andrew Lewycky Signed-off-by: Oded Gabbay --- mm/rmap.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/mm/rmap.c b/mm/rmap.c index 196cd0c..73d4c3d 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1231,13 +1231,17 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, } else dec_mm_counter(mm, MM_FILEPAGES); + pte_unmap_unlock(pte, ptl); + + mmu_notifier_invalidate_page(vma, address, event); + page_remove_rmap(page); page_cache_release(page); + return ret; + out_unmap: pte_unmap_unlock(pte, ptl); - if (ret != SWAP_FAIL && !(flags & TTU_MUNLOCK)) - mmu_notifier_invalidate_page(vma, address, event); out: return ret; -- 1.9.1 -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753796AbaGJVxl (ORCPT ); Thu, 10 Jul 2014 17:53:41 -0400 Received: from mail-wg0-f51.google.com ([74.125.82.51]:36315 "EHLO mail-wg0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753765AbaGJVxi (ORCPT ); Thu, 10 Jul 2014 17:53:38 -0400 From: Oded Gabbay X-Google-Original-From: Oded Gabbay To: Andrew Morton Cc: David Airlie , Alex Deucher , Jerome Glisse , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, John Bridgman , Andrew Lewycky , Joerg Roedel , linux-mm , Oded Gabbay , Naoya Horiguchi , Joonsoo Kim , "Kirill A. Shutemov" , Hugh Dickins , Cyrill Gorcunov , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Jianyu Zhan Subject: [PATCH 28/83] mm: Change timing of notification to IOMMUs about a page to be invalidated Date: Fri, 11 Jul 2014 00:53:26 +0300 Message-Id: <1405029208-6703-1-git-send-email-oded.gabbay@amd.com> X-Mailer: git-send-email 1.9.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andrew Lewycky This patch changes the location of the mmu_notifier_invalidate_page function call inside try_to_unmap_one. The mmu_notifier_invalidate_page function call tells the IOMMU that a pgae should be invalidated. The location is changed from after releasing the physical page to before releasing the physical page. This change should prevent the bug that would occur in the (rare) case where the GPU attempts to access a page while the CPU attempts to swap out that page (or discard it if it is not dirty). Signed-off-by: Andrew Lewycky Signed-off-by: Oded Gabbay --- mm/rmap.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/mm/rmap.c b/mm/rmap.c index 196cd0c..73d4c3d 100644 --- a/mm/rmap.c +++ b/mm/rmap.c @@ -1231,13 +1231,17 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma, } else dec_mm_counter(mm, MM_FILEPAGES); + pte_unmap_unlock(pte, ptl); + + mmu_notifier_invalidate_page(vma, address, event); + page_remove_rmap(page); page_cache_release(page); + return ret; + out_unmap: pte_unmap_unlock(pte, ptl); - if (ret != SWAP_FAIL && !(flags & TTU_MUNLOCK)) - mmu_notifier_invalidate_page(vma, address, event); out: return ret; -- 1.9.1