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From: Joerg Roedel <joro@8bytes.org>
To: iommu@lists.linux-foundation.org, Joerg Roedel <joro@8bytes.org>
Cc: Filippo Sironi <sironi@amazon.de>, jroedel@suse.de
Subject: [PATCH 4/6] iommu/amd: Check for busy devices earlier in attach_device()
Date: Wed, 25 Sep 2019 15:22:58 +0200	[thread overview]
Message-ID: <20190925132300.3038-5-joro@8bytes.org> (raw)
In-Reply-To: <20190925132300.3038-1-joro@8bytes.org>

From: Joerg Roedel <jroedel@suse.de>

Check early in attach_device whether the device is already attached to a
domain. This also simplifies the code path so that __attach_device() can
be removed.

Fixes: 92d420ec028d ("iommu/amd: Relax locking in dma_ops path")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
 drivers/iommu/amd_iommu.c | 25 +++++++------------------
 1 file changed, 7 insertions(+), 18 deletions(-)

diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 2919168577ff..459247c32dc0 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -2072,23 +2072,6 @@ static void do_detach(struct iommu_dev_data *dev_data)
 	domain->dev_cnt                 -= 1;
 }
 
-/*
- * If a device is not yet associated with a domain, this function makes the
- * device visible in the domain
- */
-static int __attach_device(struct iommu_dev_data *dev_data,
-			   struct protection_domain *domain)
-{
-	if (dev_data->domain != NULL)
-		return -EBUSY;
-
-	/* Attach alias group root */
-	do_attach(dev_data, domain);
-
-	return 0;
-}
-
-
 static void pdev_iommuv2_disable(struct pci_dev *pdev)
 {
 	pci_disable_ats(pdev);
@@ -2174,6 +2157,10 @@ static int attach_device(struct device *dev,
 
 	dev_data = get_dev_data(dev);
 
+	ret = -EBUSY;
+	if (dev_data->domain != NULL)
+		goto out;
+
 	if (!dev_is_pci(dev))
 		goto skip_ats_check;
 
@@ -2198,7 +2185,9 @@ static int attach_device(struct device *dev,
 	}
 
 skip_ats_check:
-	ret = __attach_device(dev_data, domain);
+	ret = 0;
+
+	do_attach(dev_data, domain);
 
 	/*
 	 * We might boot into a crash-kernel here. The crashed kernel
-- 
2.17.1

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  parent reply	other threads:[~2019-09-25 13:23 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-09-25 13:22 [PATCH 0/6] iommu/amd: Locking Fixes Joerg Roedel
2019-09-25 13:22 ` [PATCH 1/6] iommu/amd: Remove domain->updated Joerg Roedel
2019-09-25 15:45   ` Sironi, Filippo via iommu
2019-09-26  6:18   ` Jerry Snitselaar
2019-09-25 13:22 ` [PATCH 2/6] iommu/amd: Remove amd_iommu_devtable_lock Joerg Roedel
2019-09-25 15:50   ` Sironi, Filippo via iommu
2019-09-25 15:52     ` Sironi, Filippo via iommu
2019-09-26  6:24   ` Jerry Snitselaar
2019-09-25 13:22 ` [PATCH 3/6] iommu/amd: Take domain->lock for complete attach/detach path Joerg Roedel
2019-09-25 15:53   ` Sironi, Filippo via iommu
2019-09-26  6:34   ` Jerry Snitselaar
2019-09-25 13:22 ` Joerg Roedel [this message]
2019-09-25 15:55   ` [PATCH 4/6] iommu/amd: Check for busy devices earlier in attach_device() Sironi, Filippo via iommu
2019-09-26  6:37   ` Jerry Snitselaar
2019-09-25 13:22 ` [PATCH 5/6] iommu/amd: Lock dev_data in attach/detach code paths Joerg Roedel
2019-09-25 15:56   ` Sironi, Filippo via iommu
2019-09-26  6:41   ` Jerry Snitselaar
2019-09-25 13:23 ` [PATCH 6/6] iommu/amd: Lock code paths traversing protection_domain->dev_list Joerg Roedel
2019-09-25 15:58   ` Sironi, Filippo via iommu
2019-09-26  6:48   ` Jerry Snitselaar
2019-09-26  0:25 ` [PATCH 0/6] iommu/amd: Locking Fixes Jerry Snitselaar
2019-09-26  5:46   ` Joerg Roedel

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