iommu/vt-d: Probe DMA-capable ACPI name space devices

Some platforms may support ACPI name-space enumerated devices
that are capable of generating DMA requests. Platforms which
support DMA remapping explicitly declares any such DMA-capable
ACPI name-space devices in the platform through ACPI Name-space
Device Declaration (ANDD) structure and enumerate them through
the Device Scope of the appropriate remapping hardware unit.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 87f9f22..0bae0b7 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4796,6 +4796,48 @@ static int __init platform_optin_force_iommu(void)
        return 1;
 }
 
+static int __init probe_acpi_namespace_devices(void)
+{
+       struct dmar_drhd_unit *drhd;
+       struct intel_iommu *iommu;
+       struct device *dev;
+       int i, ret = 0;
+
+       for_each_active_iommu(iommu, drhd) {
+               for_each_active_dev_scope(drhd->devices,
+                                         drhd->devices_cnt, i, dev) {
+                       struct acpi_device_physical_node *pn;
+                       struct iommu_group *group;
+                       struct acpi_device *adev;
+
+                       if (dev->bus != &acpi_bus_type)
+                               continue;
+
+                       adev = to_acpi_device(dev);
+                       mutex_lock(&adev->physical_node_lock);
+                       list_for_each_entry(pn,
+                                           &adev->physical_node_list, node) {
+                               group = iommu_group_get(pn->dev);
+                               if (group) {
+                                       iommu_group_put(group);
+                                       continue;
+                               }
+
+                               pn->dev->bus->iommu_ops = &intel_iommu_ops;
+                               ret = iommu_probe_device(pn->dev);
+                               if (ret)
+                                       break;
+                       }
+                       mutex_unlock(&adev->physical_node_lock);
+
+                       if (ret)
+                               return ret;
+               }
+       }
+
+       return 0;
+}
+
 int __init intel_iommu_init(void)
 {
        int ret = -ENODEV;
@@ -4908,6 +4950,9 @@ int __init intel_iommu_init(void)
        cpuhp_setup_state(CPUHP_IOMMU_INTEL_DEAD, "iommu/intel:dead", NULL,
                          intel_iommu_cpu_dead);
 
+       if (probe_acpi_namespace_devices())
+               pr_warn("ACPI name space devices didn't probe correctly\n");
+
        /* Finally, we enable the DMA remapping hardware. */
        for_each_iommu(iommu, drhd) {
                if (!translation_pre_enabled(iommu))