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From:   Nicolin Chen <nicolinc@nvidia.com>
To:     <joro@8bytes.org>, <will@kernel.org>, <robin.murphy@arm.com>
CC:     <jgg@nvidia.com>, <kevin.tian@intel.com>,
        <suravee.suthikulpanit@amd.com>, <iommu@lists.linux.dev>,
        <linux-kernel@vger.kernel.org>
Subject: [PATCH v6 1/5] iommu/amd: Drop unnecessary checks in amd_iommu_attach_device()
Date:   Fri, 23 Sep 2022 00:17:01 -0700
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The same checks are done in amd_iommu_probe_device(). If any of them fails
there, then the device won't get a group, so there's no way for it to even
reach amd_iommu_attach_device anymore.

Suggested-by: Robin Murphy <robin.murphy@arm.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Reviewed-by: Vasant Hegde <vasant.hegde@amd.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
 drivers/iommu/amd/iommu.c | 12 ++----------
 1 file changed, 2 insertions(+), 10 deletions(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 828672a46a3d..930d9946b9f7 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2135,21 +2135,13 @@ static void amd_iommu_detach_device(struct iommu_domain *dom,
 static int amd_iommu_attach_device(struct iommu_domain *dom,
 				   struct device *dev)
 {
+	struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
 	struct protection_domain *domain = to_pdomain(dom);
-	struct iommu_dev_data *dev_data;
-	struct amd_iommu *iommu;
+	struct amd_iommu *iommu = rlookup_amd_iommu(dev);
 	int ret;
 
-	if (!check_device(dev))
-		return -EINVAL;
-
-	dev_data = dev_iommu_priv_get(dev);
 	dev_data->defer_attach = false;
 
-	iommu = rlookup_amd_iommu(dev);
-	if (!iommu)
-		return -EINVAL;
-
 	if (dev_data->domain)
 		detach_device(dev);
 
-- 
2.17.1