From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-la0-f45.google.com (mail-la0-f45.google.com [209.85.215.45]) by kanga.kvack.org (Postfix) with ESMTP id 2A44C900021 for ; Tue, 28 Oct 2014 13:14:27 -0400 (EDT) Received: by mail-la0-f45.google.com with SMTP id gm9so1037651lab.4 for ; Tue, 28 Oct 2014 10:14:25 -0700 (PDT) Received: from theia.8bytes.org (8bytes.org. [2a01:238:4383:600:38bc:a715:4b6d:a889]) by mx.google.com with ESMTPS id b9si3499895lbp.50.2014.10.28.10.14.20 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 28 Oct 2014 10:14:21 -0700 (PDT) From: Joerg Roedel Subject: [PATCH 3/3] mmu_notifier: Add the call-back for mmu_notifier_invalidate_range() Date: Tue, 28 Oct 2014 18:14:00 +0100 Message-Id: <1414516440-910-4-git-send-email-joro@8bytes.org> In-Reply-To: <1414516440-910-1-git-send-email-joro@8bytes.org> References: <1414516440-910-1-git-send-email-joro@8bytes.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton , Andrea Arcangeli , Peter Zijlstra , Rik van Riel , Hugh Dickins , Mel Gorman , Johannes Weiner Cc: Jerome Glisse , 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, jroedel@suse.de, joro@8bytes.org From: Joerg Roedel Now that the mmu_notifier_invalidate_range() calls are in place, add the call-back to allow subsystems to register against it. Reviewed-by: Andrea Arcangeli Reviewed-by: JA(C)rA'me Glisse Signed-off-by: Joerg Roedel --- include/linux/mmu_notifier.h | 37 ++++++++++++++++++++++++++++++++----- mm/mmu_notifier.c | 25 +++++++++++++++++++++++++ 2 files changed, 57 insertions(+), 5 deletions(-) diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h index 966da2b..94d19f6 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -98,11 +98,11 @@ struct mmu_notifier_ops { /* * invalidate_range_start() and invalidate_range_end() must be * paired and are called only when the mmap_sem and/or the - * locks protecting the reverse maps are held. The subsystem - * must guarantee that no additional references are taken to - * the pages in the range established between the call to - * invalidate_range_start() and the matching call to - * invalidate_range_end(). + * locks protecting the reverse maps are held. If the subsystem + * can't guarantee that no additional references are taken to + * the pages in the range, it has to implement the + * invalidate_range() notifier to remove any references taken + * after invalidate_range_start(). * * Invalidation of multiple concurrent ranges may be * optionally permitted by the driver. Either way the @@ -144,6 +144,29 @@ struct mmu_notifier_ops { void (*invalidate_range_end)(struct mmu_notifier *mn, struct mm_struct *mm, unsigned long start, unsigned long end); + + /* + * invalidate_range() is either called between + * invalidate_range_start() and invalidate_range_end() when the + * VM has to free pages that where unmapped, but before the + * pages are actually freed, or outside of _start()/_end() when + * a (remote) TLB is necessary. + * + * If invalidate_range() is used to manage a non-CPU TLB with + * shared page-tables, it not necessary to implement the + * invalidate_range_start()/end() notifiers, as + * invalidate_range() alread catches the points in time when an + * external TLB range needs to be flushed. + * + * The invalidate_range() function is called under the ptl + * spin-lock and not allowed to sleep. + * + * Note that this function might be called with just a sub-range + * of what was passed to invalidate_range_start()/end(), if + * called between those functions. + */ + void (*invalidate_range)(struct mmu_notifier *mn, struct mm_struct *mm, + unsigned long start, unsigned long end); }; /* @@ -190,6 +213,8 @@ extern void __mmu_notifier_invalidate_range_start(struct mm_struct *mm, unsigned long start, unsigned long end); extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, unsigned long start, unsigned long end); +extern void __mmu_notifier_invalidate_range(struct mm_struct *mm, + unsigned long start, unsigned long end); static inline void mmu_notifier_release(struct mm_struct *mm) { @@ -245,6 +270,8 @@ 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) { + if (mm_has_notifiers(mm)) + __mmu_notifier_invalidate_range(mm, start, end); } static inline void mmu_notifier_mm_init(struct mm_struct *mm) diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 2c8da98..3b9b3d0 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -193,6 +193,16 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, id = srcu_read_lock(&srcu); hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { + /* + * Call invalidate_range here too to avoid the need for the + * subsystem of having to register an invalidate_range_end + * call-back when there is invalidate_range already. Usually a + * subsystem registers either invalidate_range_start()/end() or + * invalidate_range(), so this will be no additional overhead + * (besides the pointer check). + */ + if (mn->ops->invalidate_range) + mn->ops->invalidate_range(mn, mm, start, end); if (mn->ops->invalidate_range_end) mn->ops->invalidate_range_end(mn, mm, start, end); } @@ -200,6 +210,21 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm, } EXPORT_SYMBOL_GPL(__mmu_notifier_invalidate_range_end); +void __mmu_notifier_invalidate_range(struct mm_struct *mm, + unsigned long start, unsigned long end) +{ + struct mmu_notifier *mn; + int id; + + id = srcu_read_lock(&srcu); + hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) { + if (mn->ops->invalidate_range) + mn->ops->invalidate_range(mn, mm, start, end); + } + srcu_read_unlock(&srcu, id); +} +EXPORT_SYMBOL_GPL(__mmu_notifier_invalidate_range); + static int do_mmu_notifier_register(struct mmu_notifier *mn, struct mm_struct *mm, int take_mmap_sem) -- 1.8.4.5 -- 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