Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753533AbaG2QSS (ORCPT ); Tue, 29 Jul 2014 12:18:18 -0400 Received: from 8bytes.org ([81.169.241.247]:52459 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751583AbaG2QSR (ORCPT ); Tue, 29 Jul 2014 12:18:17 -0400 From: Joerg Roedel To: Andrew Morton , Andrea Arcangeli , Peter Zijlstra , Rik van Riel , Hugh Dickins , Mel Gorman , Johannes Weiner Cc: Jerome Glisse , jroedel@suse.de, Jay.Cornwall@amd.com, Oded.Gabbay@amd.com, John.Bridgman@amd.com, Suravee.Suthikulpanit@amd.com, ben.sander@amd.com, Jesse Barnes , David Woodhouse , linux-kernel@vger.kernel.org, linux-mm@kvack.org, iommu@lists.linux-foundation.org Subject: [PATCH 1/3] mmu_notifier: Add mmu_notifier_invalidate_range() Date: Tue, 29 Jul 2014 18:18:11 +0200 Message-Id: <1406650693-23315-2-git-send-email-joro@8bytes.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1406650693-23315-1-git-send-email-joro@8bytes.org> References: <1406650693-23315-1-git-send-email-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joerg Roedel This notifier closes two important gaps with the current invalidate_range_start()/end() notifiers. The _start() part is called when all pages are still mapped while the _end() notifier is called when all pages are potentially unmapped and already freed. This does not allow to manage external (non-CPU) hardware TLBs with MMU-notifiers because there is no way to prevent that hardware will establish new TLB entries between the calls of these two functions. But this is a requirement to the subsytem that implements these existing notifiers. To allow managing external TLBs the MMU-notifiers need to catch the moment when pages are unmapped but not yet freed. This new notifier catches that moment and notifies the interested subsytem when pages that were unmapped are about to be freed. The new notifier will be called between invalidate_range_start()/end() to catch the moment when pages are unmapped but not yet freed. For non-CPU TLBs it is also necessary to know when page-table pages are freed. This is the second gap in current mmu_notifiers. At those events the new notifier will also be called, without calling invalidate_range_start() and invalidate_range_end() around it. Signed-off-by: Joerg Roedel --- include/linux/mmu_notifier.h | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index deca874..1bac99c 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -235,6 +235,11 @@ static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm, __mmu_notifier_invalidate_range_end(mm, start, end); } +static inline void mmu_notifier_invalidate_range(struct mm_struct *mm, + unsigned long start, unsigned long end) +{ +} + static inline void mmu_notifier_mm_init(struct mm_struct *mm) { mm->mmu_notifier_mm = NULL; @@ -326,6 +331,11 @@ static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm, { } +static inline void mmu_notifier_invalidate_range(struct mm_struct *mm, + unsigned long start, unsigned long end) +{ +} + static inline void mmu_notifier_mm_init(struct mm_struct *mm) { } -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/