AMD IOMMU: add device notifier callback

Impact: inform IOMMU about state change of a device in the driver core

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

1 files changed, 60 insertions, 2 deletions

diff --git a/arch/x86/kernel/amd_iommu.c b/arch/x86/kernel/amd_iommu.c
index 15456a3a18c8..140875b3f6ef 100644
--- a/arch/x86/kernel/amd_iommu.c
+++ b/arch/x86/kernel/amd_iommu.c
@@ -47,6 +47,8 @@ struct iommu_cmd {
 
 static int dma_ops_unity_map(struct dma_ops_domain *dma_dom,
                              struct unity_map_entry *e);
+static struct dma_ops_domain *find_protection_domain(u16 devid);
+
 
 /* returns !0 if the IOMMU is caching non-present entries in its TLB */
 static int iommu_has_npcache(struct amd_iommu *iommu)
@@ -844,7 +846,6 @@ static void attach_device(struct amd_iommu *iommu,
         iommu_queue_inv_dev_entry(iommu, devid);
 }
 
-#ifdef CONFIG_IOMMU_API
 /*
  * Removes a device from a protection domain (unlocked)
  */
@@ -881,7 +882,62 @@ static void detach_device(struct protection_domain *domain, u16 devid)
         __detach_device(domain, devid);
         write_unlock_irqrestore(&amd_iommu_devtable_lock, flags);
 }
-#endif
+
+static int device_change_notifier(struct notifier_block *nb,
+                                  unsigned long action, void *data)
+{
+        struct device *dev = data;
+        struct pci_dev *pdev = to_pci_dev(dev);
+        u16 devid = calc_devid(pdev->bus->number, pdev->devfn);
+        struct protection_domain *domain;
+        struct dma_ops_domain *dma_domain;
+        struct amd_iommu *iommu;
+
+        if (devid > amd_iommu_last_bdf)
+                goto out;
+
+        devid = amd_iommu_alias_table[devid];
+
+        iommu = amd_iommu_rlookup_table[devid];
+        if (iommu == NULL)
+                goto out;
+
+        domain = domain_for_device(devid);
+
+        if (domain && !dma_ops_domain(domain))
+                WARN_ONCE(1, "AMD IOMMU WARNING: device %s already bound "
+                          "to a non-dma-ops domain\n", dev_name(dev));
+
+        switch (action) {
+        case BUS_NOTIFY_BOUND_DRIVER:
+                if (domain)
+                        goto out;
+                dma_domain = find_protection_domain(devid);
+                if (!dma_domain)
+                        dma_domain = iommu->default_dom;
+                attach_device(iommu, &dma_domain->domain, devid);
+                printk(KERN_INFO "AMD IOMMU: Using protection domain %d for "
+                       "device %s\n", dma_domain->domain.id, dev_name(dev));
+                break;
+        case BUS_NOTIFY_UNBIND_DRIVER:
+                if (!domain)
+                        goto out;
+                detach_device(domain, devid);
+                break;
+        default:
+                goto out;
+        }
+
+        iommu_queue_inv_dev_entry(iommu, devid);
+        iommu_completion_wait(iommu);
+
+out:
+        return 0;
+}
+
+struct notifier_block device_nb = {
+        .notifier_call = device_change_notifier,
+};
 
 /*****************************************************************************
  *
@@ -1510,6 +1566,8 @@ int __init amd_iommu_init_dma_ops(void)
         /* Make the driver finally visible to the drivers */
         dma_ops = &amd_iommu_dma_ops;
 
+        bus_register_notifier(&pci_bus_type, &device_nb);
+
         return 0;
 
 free_domains: