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From:   Filippo Sironi <sironi@amazon.de>
To:     sironi@amazon.de, joro@8bytes.org,
        iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
Cc:     Wei Wang <wawei@amazon.de>
Subject: [PATCH 5/5] iommu/amd: Hold the domain lock when calling domain_flush_tlb[_pde]
Date:   Tue, 10 Sep 2019 19:49:25 +0200
Message-Id: <1568137765-20278-6-git-send-email-sironi@amazon.de>
In-Reply-To: <1568137765-20278-1-git-send-email-sironi@amazon.de>
References: <1568137765-20278-1-git-send-email-sironi@amazon.de>
Sender: linux-kernel-owner@vger.kernel.org
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From: Wei Wang <wawei@amazon.de>

domain_flush_tlb[_pde] traverses the device list, which is protected by
the domain lock.

Signed-off-by: Wei Wang <wawei@amazon.de>
Signed-off-by: Filippo Sironi <sironi@amazon.de>
---
 drivers/iommu/amd_iommu.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 3714ae5ded31..f5df23acd1c7 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1806,7 +1806,11 @@ static void free_gcr3_table(struct protection_domain *domain)
 
 static void dma_ops_domain_flush_tlb(struct dma_ops_domain *dom)
 {
+	unsigned long flags;
+
+	spin_lock_irqsave(&dom->domain.lock, flags);
 	domain_flush_tlb(&dom->domain);
+	spin_unlock_irqrestore(&dom->domain.lock, flags);
 	domain_flush_complete(&dom->domain);
 }
 
@@ -2167,7 +2171,9 @@ static int attach_device(struct device *dev,
 	 * left the caches in the IOMMU dirty. So we have to flush
 	 * here to evict all dirty stuff.
 	 */
+	spin_lock_irqsave(&domain->lock, flags);
 	domain_flush_tlb_pde(domain);
+	spin_unlock_irqrestore(&domain->lock, flags);
 
 	domain_flush_complete(domain);
 
@@ -3245,8 +3251,11 @@ static bool amd_iommu_is_attach_deferred(struct iommu_domain *domain,
 static void amd_iommu_flush_iotlb_all(struct iommu_domain *domain)
 {
 	struct protection_domain *dom = to_pdomain(domain);
+	unsigned long flags;
 
+	spin_lock_irqsave(&dom->lock, flags);
 	domain_flush_tlb_pde(dom);
+	spin_unlock_irqrestore(&dom->lock, flags);
 	domain_flush_complete(dom);
 }
 
-- 
2.7.4