iommu/arm-smmu: Don't unregister on shutdown

[platform/kernel/linux-starfive.git] / drivers / iommu / s390-iommu.c

diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c
index 3c07178..c2e5e81 100644 (file)
--- a/drivers/iommu/s390-iommu.c
+++ b/drivers/iommu/s390-iommu.c
@@ -79,10 +79,36 @@ static void s390_domain_free(struct iommu_domain *domain)
 {
        struct s390_domain *s390_domain = to_s390_domain(domain);
 
+       WARN_ON(!list_empty(&s390_domain->devices));
        dma_cleanup_tables(s390_domain->dma_table);
        kfree(s390_domain);
 }
 
+static void __s390_iommu_detach_device(struct zpci_dev *zdev)
+{
+       struct s390_domain *s390_domain = zdev->s390_domain;
+       struct s390_domain_device *domain_device, *tmp;
+       unsigned long flags;
+
+       if (!s390_domain)
+               return;
+
+       spin_lock_irqsave(&s390_domain->list_lock, flags);
+       list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices,
+                                list) {
+               if (domain_device->zdev == zdev) {
+                       list_del(&domain_device->list);
+                       kfree(domain_device);
+                       break;
+               }
+       }
+       spin_unlock_irqrestore(&s390_domain->list_lock, flags);
+
+       zpci_unregister_ioat(zdev, 0);
+       zdev->s390_domain = NULL;
+       zdev->dma_table = NULL;
+}
+
 static int s390_iommu_attach_device(struct iommu_domain *domain,
                                    struct device *dev)
 {
@@ -90,7 +116,7 @@ static int s390_iommu_attach_device(struct iommu_domain *domain,
        struct zpci_dev *zdev = to_zpci_dev(dev);
        struct s390_domain_device *domain_device;
        unsigned long flags;
-       int cc, rc;
+       int cc, rc = 0;
 
        if (!zdev)
                return -ENODEV;
@@ -99,24 +125,18 @@ static int s390_iommu_attach_device(struct iommu_domain *domain,
        if (!domain_device)
                return -ENOMEM;
 
-       if (zdev->dma_table && !zdev->s390_domain) {
-               cc = zpci_dma_exit_device(zdev);
-               if (cc) {
-                       rc = -EIO;
-                       goto out_free;
-               }
-       }
-
        if (zdev->s390_domain)
-               zpci_unregister_ioat(zdev, 0);
+               __s390_iommu_detach_device(zdev);
+       else if (zdev->dma_table)
+               zpci_dma_exit_device(zdev);
 
-       zdev->dma_table = s390_domain->dma_table;
        cc = zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
-                               virt_to_phys(zdev->dma_table));
+                               virt_to_phys(s390_domain->dma_table));
        if (cc) {
                rc = -EIO;
-               goto out_restore;
+               goto out_free;
        }
+       zdev->dma_table = s390_domain->dma_table;
 
        spin_lock_irqsave(&s390_domain->list_lock, flags);
        /* First device defines the DMA range limits */
@@ -127,9 +147,9 @@ static int s390_iommu_attach_device(struct iommu_domain *domain,
        /* Allow only devices with identical DMA range limits */
        } else if (domain->geometry.aperture_start != zdev->start_dma ||
                   domain->geometry.aperture_end != zdev->end_dma) {
-               rc = -EINVAL;
                spin_unlock_irqrestore(&s390_domain->list_lock, flags);
-               goto out_restore;
+               rc = -EINVAL;
+               goto out_unregister;
        }
        domain_device->zdev = zdev;
        zdev->s390_domain = s390_domain;
@@ -138,14 +158,9 @@ static int s390_iommu_attach_device(struct iommu_domain *domain,
 
        return 0;
 
-out_restore:
-       if (!zdev->s390_domain) {
-               zpci_dma_init_device(zdev);
-       } else {
-               zdev->dma_table = zdev->s390_domain->dma_table;
-               zpci_register_ioat(zdev, 0, zdev->start_dma, zdev->end_dma,
-                                  virt_to_phys(zdev->dma_table));
-       }
+out_unregister:
+       zpci_unregister_ioat(zdev, 0);
+       zdev->dma_table = NULL;
 out_free:
        kfree(domain_device);
 
@@ -155,32 +170,12 @@ out_free:
 static void s390_iommu_detach_device(struct iommu_domain *domain,
                                     struct device *dev)
 {
-       struct s390_domain *s390_domain = to_s390_domain(domain);
        struct zpci_dev *zdev = to_zpci_dev(dev);
-       struct s390_domain_device *domain_device, *tmp;
-       unsigned long flags;
-       int found = 0;
 
-       if (!zdev)
-               return;
+       WARN_ON(zdev->s390_domain != to_s390_domain(domain));
 
-       spin_lock_irqsave(&s390_domain->list_lock, flags);
-       list_for_each_entry_safe(domain_device, tmp, &s390_domain->devices,
-                                list) {
-               if (domain_device->zdev == zdev) {
-                       list_del(&domain_device->list);
-                       kfree(domain_device);
-                       found = 1;
-                       break;
-               }
-       }
-       spin_unlock_irqrestore(&s390_domain->list_lock, flags);
-
-       if (found && (zdev->s390_domain == s390_domain)) {
-               zdev->s390_domain = NULL;
-               zpci_unregister_ioat(zdev, 0);
-               zpci_dma_init_device(zdev);
-       }
+       __s390_iommu_detach_device(zdev);
+       zpci_dma_init_device(zdev);
 }
 
 static struct iommu_device *s390_iommu_probe_device(struct device *dev)
@@ -198,24 +193,13 @@ static struct iommu_device *s390_iommu_probe_device(struct device *dev)
 static void s390_iommu_release_device(struct device *dev)
 {
        struct zpci_dev *zdev = to_zpci_dev(dev);
-       struct iommu_domain *domain;
 
        /*
-        * This is a workaround for a scenario where the IOMMU API common code
-        * "forgets" to call the detach_dev callback: After binding a device
-        * to vfio-pci and completing the VFIO_SET_IOMMU ioctl (which triggers
-        * the attach_dev), removing the device via
-        * "echo 1 > /sys/bus/pci/devices/.../remove" won't trigger detach_dev,
-        * only release_device will be called via the BUS_NOTIFY_REMOVED_DEVICE
-        * notifier.
-        *
-        * So let's call detach_dev from here if it hasn't been called before.
+        * release_device is expected to detach any domain currently attached
+        * to the device, but keep it attached to other devices in the group.
         */
-       if (zdev && zdev->s390_domain) {
-               domain = iommu_get_domain_for_dev(dev);
-               if (domain)
-                       s390_iommu_detach_device(domain, dev);
-       }
+       if (zdev)
+               __s390_iommu_detach_device(zdev);
 }
 
 static int s390_iommu_update_trans(struct s390_domain *s390_domain,