The AMD IOMMU supports default domain, so the detach_dev op will never
be called. Remove it to avoid dead code.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
---
 drivers/iommu/amd/iommu.c | 26 --------------------------
 1 file changed, 26 deletions(-)

diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 5c381cc3658e..bd1970b4f48b 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c
@@ -2126,31 +2126,6 @@ static void amd_iommu_domain_free(struct iommu_domain *dom)
 	protection_domain_free(domain);
 }
 
-static void amd_iommu_detach_device(struct iommu_domain *dom,
-				    struct device *dev)
-{
-	struct iommu_dev_data *dev_data = dev_iommu_priv_get(dev);
-	struct amd_iommu *iommu;
-
-	if (!check_device(dev))
-		return;
-
-	if (dev_data->domain != NULL)
-		detach_device(dev);
-
-	iommu = rlookup_amd_iommu(dev);
-	if (!iommu)
-		return;
-
-#ifdef CONFIG_IRQ_REMAP
-	if (AMD_IOMMU_GUEST_IR_VAPIC(amd_iommu_guest_ir) &&
-	    (dom->type == IOMMU_DOMAIN_UNMANAGED))
-		dev_data->use_vapic = 0;
-#endif
-
-	iommu_completion_wait(iommu);
-}
-
 static int amd_iommu_attach_device(struct iommu_domain *dom,
 				   struct device *dev)
 {
@@ -2414,7 +2389,6 @@ const struct iommu_ops amd_iommu_ops = {
 	.def_domain_type = amd_iommu_def_domain_type,
 	.default_domain_ops = &(const struct iommu_domain_ops) {
 		.attach_dev	= amd_iommu_attach_device,
-		.detach_dev	= amd_iommu_detach_device,
 		.map_pages	= amd_iommu_map_pages,
 		.unmap_pages	= amd_iommu_unmap_pages,
 		.iotlb_sync_map	= amd_iommu_iotlb_sync_map,
-- 
2.34.1

On Mon, Nov 28, 2022 at 02:46:29PM +0800, Lu Baolu wrote:
> The AMD IOMMU supports default domain, so the detach_dev op will never
> be called. Remove it to avoid dead code.
> 
> Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
> ---
>  drivers/iommu/amd/iommu.c | 26 --------------------------
>  1 file changed, 26 deletions(-)

Driver oweners should look at what their detach_dev does and comment
in this series - eg if this is actually blocking DMA then it would be
great to convert it into a blocking domain.

But there is no issue with deleting it, and the blocking domain is an
optimization.

Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>

Jason