From 9ce3a72cd7f7e0b9ba1c5952e4461b363824bca9 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 22 Jun 2017 12:16:33 +0200 Subject: [PATCH] iommu/amd: Free already flushed ring-buffer entries before full-check To benefit from IOTLB flushes on other CPUs we have to free the already flushed IOVAs from the ring-buffer before we do the queue_ring_full() check. Signed-off-by: Joerg Roedel --- drivers/iommu/amd_iommu.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index 95ee360a5199..c618c26a3b33 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -1910,15 +1910,21 @@ static void queue_add(struct dma_ops_domain *dom, queue = get_cpu_ptr(dom->flush_queue); spin_lock_irqsave(&queue->lock, flags); + /* + * First remove the enries from the ring-buffer that are already + * flushed to make the below queue_ring_full() check less likely + */ + queue_ring_free_flushed(dom, queue); + /* * When ring-queue is full, flush the entries from the IOTLB so * that we can free all entries with queue_ring_free_flushed() * below. */ - if (queue_ring_full(queue)) + if (queue_ring_full(queue)) { dma_ops_domain_flush_tlb(dom); - - queue_ring_free_flushed(dom, queue); + queue_ring_free_flushed(dom, queue); + } idx = queue_ring_add(queue);