Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753961AbaG2QSp (ORCPT ); Tue, 29 Jul 2014 12:18:45 -0400 Received: from 8bytes.org ([81.169.241.247]:52458 "EHLO theia.8bytes.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751575AbaG2QSR (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 3/3] mmu_notifier: Add the call-back for mmu_notifier_invalidate_range() Date: Tue, 29 Jul 2014 18:18:13 +0200 Message-Id: <1406650693-23315-4-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 Now that the mmu_notifier_invalidate_range() calls are in place, add the call-back to allow subsystems to register against it. 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 f760e95..596ea08 100644 --- a/include/linux/mmu_notifier.h +++ b/include/linux/mmu_notifier.h @@ -95,11 +95,11 @@ 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 @@ -141,6 +141,29 @@ 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 + * page-table pages are about to be freed. + * + * 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); }; /* @@ -184,6 +207,8 @@ 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) { @@ -238,6 +263,8 @@ 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 41cefdf..e8ecbed 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -173,6 +173,16 @@ 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); } @@ -180,6 +190,21 @@ 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) -- 1.9.1 -- 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/