From ec131b2d7fa629edf88a1f51669d1b4a189cba44 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= Date: Tue, 30 Oct 2018 15:04:28 -0700 Subject: [PATCH] mm/hmm: invalidate device page table at start of invalidation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Invalidate device page table at start of invalidation and invalidate in progress CPU page table snapshooting at both start and end of any invalidation. This is helpful when device need to dirty page because the device page table report the page as dirty. Dirtying page must happen in the start mmu notifier callback and not in the end one. Link: http://lkml.kernel.org/r/20181019160442.18723-7-jglisse@redhat.com Signed-off-by: Jérôme Glisse Cc: Ralph Campbell Cc: John Hubbard Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hmm.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/mm/hmm.c b/mm/hmm.c index b4e9afdc2181..90c34f3d1243 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -43,7 +43,6 @@ static const struct mmu_notifier_ops hmm_mmu_notifier_ops; * * @mm: mm struct this HMM struct is bound to * @lock: lock protecting ranges list - * @sequence: we track updates to the CPU page table with a sequence number * @ranges: list of range being snapshotted * @mirrors: list of mirrors for this mm * @mmu_notifier: mmu notifier to track updates to CPU page table @@ -52,7 +51,6 @@ static const struct mmu_notifier_ops hmm_mmu_notifier_ops; struct hmm { struct mm_struct *mm; spinlock_t lock; - atomic_t sequence; struct list_head ranges; struct list_head mirrors; struct mmu_notifier mmu_notifier; @@ -85,7 +83,6 @@ static struct hmm *hmm_register(struct mm_struct *mm) return NULL; INIT_LIST_HEAD(&hmm->mirrors); init_rwsem(&hmm->mirrors_sem); - atomic_set(&hmm->sequence, 0); hmm->mmu_notifier.ops = NULL; INIT_LIST_HEAD(&hmm->ranges); spin_lock_init(&hmm->lock); @@ -126,7 +123,7 @@ void hmm_mm_destroy(struct mm_struct *mm) kfree(mm->hmm); } -static int hmm_invalidate_range(struct hmm *hmm, +static int hmm_invalidate_range(struct hmm *hmm, bool device, const struct hmm_update *update) { struct hmm_mirror *mirror; @@ -147,6 +144,9 @@ static int hmm_invalidate_range(struct hmm *hmm, } spin_unlock(&hmm->lock); + if (!device) + return 0; + down_read(&hmm->mirrors_sem); list_for_each_entry(mirror, &hmm->mirrors, list) { int ret; @@ -189,18 +189,21 @@ static void hmm_release(struct mmu_notifier *mn, struct mm_struct *mm) } static int hmm_invalidate_range_start(struct mmu_notifier *mn, - struct mm_struct *mm, - unsigned long start, - unsigned long end, - bool blockable) + struct mm_struct *mm, + unsigned long start, + unsigned long end, + bool blockable) { + struct hmm_update update; struct hmm *hmm = mm->hmm; VM_BUG_ON(!hmm); - atomic_inc(&hmm->sequence); - - return 0; + update.start = start; + update.end = end; + update.event = HMM_UPDATE_INVALIDATE; + update.blockable = blockable; + return hmm_invalidate_range(hmm, true, &update); } static void hmm_invalidate_range_end(struct mmu_notifier *mn, @@ -217,7 +220,7 @@ static void hmm_invalidate_range_end(struct mmu_notifier *mn, update.end = end; update.event = HMM_UPDATE_INVALIDATE; update.blockable = true; - hmm_invalidate_range(hmm, &update); + hmm_invalidate_range(hmm, false, &update); } static const struct mmu_notifier_ops hmm_mmu_notifier_ops = {