dmaengine: idxd: enable SVA feature for IOMMU

Enable IOMMU_DEV_FEAT_SVA before attempt to bind pasid. This is needed
according to iommu_sva_bind_device() comment. Currently Intel IOMMU code
does this before bind call. It really needs to be controlled by the driver.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/161894440621.3202472.17644507396206848134.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index ef58750c24cc00360efbe4f16f67edc97a97a607..eb0b3a00a2d7e690c2d0dd5e82a59553184e3127 100644 (file)
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -501,11 +501,18 @@ static int idxd_probe(struct idxd_device *idxd)
        dev_dbg(dev, "IDXD reset complete\n");
 
        if (IS_ENABLED(CONFIG_INTEL_IDXD_SVM) && sva) {
-               rc = idxd_enable_system_pasid(idxd);
-               if (rc < 0)
-                       dev_warn(dev, "Failed to enable PASID. No SVA support: %d\n", rc);
-               else
-                       set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
+               rc = iommu_dev_enable_feature(dev, IOMMU_DEV_FEAT_SVA);
+               if (rc == 0) {
+                       rc = idxd_enable_system_pasid(idxd);
+                       if (rc < 0) {
+                               iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
+                               dev_warn(dev, "Failed to enable PASID. No SVA support: %d\n", rc);
+                       } else {
+                               set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
+                       }
+               } else {
+                       dev_warn(dev, "Unable to turn on SVA feature.\n");
+               }
        } else if (!sva) {
                dev_warn(dev, "User forced SVA off via module param.\n");
        }
@@ -539,6 +546,7 @@ static int idxd_probe(struct idxd_device *idxd)
  err:
        if (device_pasid_enabled(idxd))
                idxd_disable_system_pasid(idxd);
+       iommu_dev_disable_feature(dev, IOMMU_DEV_FEAT_SVA);
        return rc;
 }
 
@@ -699,6 +707,7 @@ static void idxd_remove(struct pci_dev *pdev)
        if (device_pasid_enabled(idxd))
                idxd_disable_system_pasid(idxd);
        idxd_unregister_devices(idxd);
+       iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_SVA);
 }
 
 static struct pci_driver idxd_pci_driver = {