From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joerg Roedel Subject: [PATCH 4/7] iommu/amd: Add locking to per-domain flush-queue Date: Wed, 7 Jun 2017 16:58:17 +0200 Message-ID: <1496847500-6781-5-git-send-email-joro@8bytes.org> References: <1496847500-6781-1-git-send-email-joro@8bytes.org> Return-path: In-Reply-To: <1496847500-6781-1-git-send-email-joro@8bytes.org> Sender: linux-kernel-owner@vger.kernel.org To: iommu@lists.linux-foundation.org Cc: linux-kernel@vger.kernel.org, Tom Lendacky , Arindam Nath , Joerg Roedel List-Id: iommu@lists.linux-foundation.org From: Joerg Roedel With locking we can safely access the flush-queues of other cpus. Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 6a5c858..9aa2735 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -144,6 +144,7 @@ struct flush_queue_entry { struct flush_queue { struct flush_queue_entry *entries; unsigned head, tail; + spinlock_t lock; }; /* @@ -1773,6 +1774,8 @@ static int dma_ops_domain_alloc_flush_queue(struct dma_ops_domain *dom) dma_ops_domain_free_flush_queue(dom); return -ENOMEM; } + + spin_lock_init(&queue->lock); } return 0; @@ -1780,6 +1783,8 @@ static int dma_ops_domain_alloc_flush_queue(struct dma_ops_domain *dom) static inline bool queue_ring_full(struct flush_queue *queue) { + assert_spin_locked(&queue->lock); + return (((queue->tail + 1) % FLUSH_QUEUE_SIZE) == queue->head); } @@ -1791,6 +1796,8 @@ static void queue_release(struct dma_ops_domain *dom, { unsigned i; + assert_spin_locked(&queue->lock); + queue_ring_for_each(i, queue) free_iova_fast(&dom->iovad, queue->entries[i].iova_pfn, @@ -1803,6 +1810,7 @@ static inline unsigned queue_ring_add(struct flush_queue *queue) { unsigned idx = queue->tail; + assert_spin_locked(&queue->lock); queue->tail = (idx + 1) % FLUSH_QUEUE_SIZE; return idx; @@ -1812,12 +1820,14 @@ static void queue_add(struct dma_ops_domain *dom, unsigned long address, unsigned long pages) { struct flush_queue *queue; + unsigned long flags; int idx; pages = __roundup_pow_of_two(pages); address >>= PAGE_SHIFT; queue = get_cpu_ptr(dom->flush_queue); + spin_lock_irqsave(&queue->lock, flags); if (queue_ring_full(queue)) { domain_flush_tlb(&dom->domain); @@ -1830,6 +1840,7 @@ static void queue_add(struct dma_ops_domain *dom, queue->entries[idx].iova_pfn = address; queue->entries[idx].pages = pages; + spin_unlock_irqrestore(&queue->lock, flags); put_cpu_ptr(dom->flush_queue); } -- 2.7.4