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>

1 files changed, 45 insertions, 0 deletions

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 87f9f2237238..0bae0b73076c 100644
--- 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))