iommu/arm-smmu: handle multi-alias IOMMU groups for PCI devices
authorWill Deacon <will.deacon@arm.com>
Mon, 19 Jan 2015 14:27:33 +0000 (14:27 +0000)
committerWill Deacon <will.deacon@arm.com>
Fri, 27 Mar 2015 13:39:36 +0000 (13:39 +0000)
IOMMU groups for PCI devices can correspond to multiple DMA aliases due
to things like ACS and PCI quirks.

This patch extends the ARM SMMU ->add_device callback so that we
consider all of the DMA aliases for a PCI IOMMU group, rather than
creating a separate group for each Requester ID.

Signed-off-by: Will Deacon <will.deacon@arm.com>
drivers/iommu/arm-smmu.c

index 161dd46..6ac1846 100644 (file)
@@ -1330,61 +1330,83 @@ static void __arm_smmu_release_pci_iommudata(void *data)
        kfree(data);
 }
 
-static int arm_smmu_add_device(struct device *dev)
+static int arm_smmu_add_pci_device(struct pci_dev *pdev)
 {
-       struct arm_smmu_device *smmu;
-       struct arm_smmu_master_cfg *cfg;
+       int i, ret;
+       u16 sid;
        struct iommu_group *group;
-       void (*releasefn)(void *) = NULL;
-       int ret;
-
-       smmu = find_smmu_for_device(dev);
-       if (!smmu)
-               return -ENODEV;
+       struct arm_smmu_master_cfg *cfg;
 
-       group = iommu_group_alloc();
-       if (IS_ERR(group)) {
-               dev_err(dev, "Failed to allocate IOMMU group\n");
+       group = iommu_group_get_for_dev(&pdev->dev);
+       if (IS_ERR(group))
                return PTR_ERR(group);
-       }
-
-       if (dev_is_pci(dev)) {
-               struct pci_dev *pdev = to_pci_dev(dev);
 
+       cfg = iommu_group_get_iommudata(group);
+       if (!cfg) {
                cfg = kzalloc(sizeof(*cfg), GFP_KERNEL);
                if (!cfg) {
                        ret = -ENOMEM;
                        goto out_put_group;
                }
 
-               cfg->num_streamids = 1;
-               /*
-                * Assume Stream ID == Requester ID for now.
-                * We need a way to describe the ID mappings in FDT.
-                */
-               pci_for_each_dma_alias(pdev, __arm_smmu_get_pci_sid,
-                                      &cfg->streamids[0]);
-               releasefn = __arm_smmu_release_pci_iommudata;
-       } else {
-               struct arm_smmu_master *master;
-
-               master = find_smmu_master(smmu, dev->of_node);
-               if (!master) {
-                       ret = -ENODEV;
-                       goto out_put_group;
-               }
+               iommu_group_set_iommudata(group, cfg,
+                                         __arm_smmu_release_pci_iommudata);
+       }
 
-               cfg = &master->cfg;
+       if (cfg->num_streamids >= MAX_MASTER_STREAMIDS) {
+               ret = -ENOSPC;
+               goto out_put_group;
        }
 
-       iommu_group_set_iommudata(group, cfg, releasefn);
-       ret = iommu_group_add_device(group, dev);
+       /*
+        * Assume Stream ID == Requester ID for now.
+        * We need a way to describe the ID mappings in FDT.
+        */
+       pci_for_each_dma_alias(pdev, __arm_smmu_get_pci_sid, &sid);
+       for (i = 0; i < cfg->num_streamids; ++i)
+               if (cfg->streamids[i] == sid)
+                       break;
+
+       /* Avoid duplicate SIDs, as this can lead to SMR conflicts */
+       if (i == cfg->num_streamids)
+               cfg->streamids[cfg->num_streamids++] = sid;
 
+       return 0;
 out_put_group:
        iommu_group_put(group);
        return ret;
 }
 
+static int arm_smmu_add_platform_device(struct device *dev)
+{
+       struct iommu_group *group;
+       struct arm_smmu_master *master;
+       struct arm_smmu_device *smmu = find_smmu_for_device(dev);
+
+       if (!smmu)
+               return -ENODEV;
+
+       master = find_smmu_master(smmu, dev->of_node);
+       if (!master)
+               return -ENODEV;
+
+       /* No automatic group creation for platform devices */
+       group = iommu_group_alloc();
+       if (IS_ERR(group))
+               return PTR_ERR(group);
+
+       iommu_group_set_iommudata(group, &master->cfg, NULL);
+       return iommu_group_add_device(group, dev);
+}
+
+static int arm_smmu_add_device(struct device *dev)
+{
+       if (dev_is_pci(dev))
+               return arm_smmu_add_pci_device(to_pci_dev(dev));
+
+       return arm_smmu_add_platform_device(dev);
+}
+
 static void arm_smmu_remove_device(struct device *dev)
 {
        iommu_group_remove_device(dev);