[Patch V2 4/4] iommu/vt-d: refine dmar_acpi_dev_scope_init() with dmar_walk_dmar_table()

[Wei Yang]

dmar_acpi_dev_scope_init() iterates on the remapping structure and just do
proper job for ANDD structure. This is the what dmar_walk_dmar_table()
does.

This patch improves the code with dmar_walk_dmar_table().

Signed-off-by: Wei Yang <richard.weiy...@gmail.com>
---
 drivers/iommu/dmar.c |   56 ++++++++++++++++++++++++++++----------------------
 1 file changed, 32 insertions(+), 24 deletions(-)

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 82f0b92..538e260 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -733,36 +733,44 @@ static void __init dmar_acpi_insert_dev_scope(u8 
device_number,
                device_number, dev_name(&adev->dev));
 }
 
-static int __init dmar_acpi_dev_scope_init(void)
+static int __dmar_acpi_dev_scope_init(struct acpi_dmar_header *header,
+                                     void *arg)
 {
        struct acpi_dmar_andd *andd;
+       acpi_handle h;
+       struct acpi_device *adev;
+
+       andd = (struct acpi_dmar_andd *)header;
+       if (!ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT,
+                                         andd->device_name,
+                                         &h))) {
+               pr_err("Failed to find handle for ACPI object %s\n",
+                      andd->device_name);
+               return 0;
+       }
+       if (acpi_bus_get_device(h, &adev)) {
+               pr_err("Failed to get device for ACPI object %s\n",
+                      andd->device_name);
+               return 0;
+       }
+       dmar_acpi_insert_dev_scope(andd->device_number, adev);
+       return 0;
+}
+
+static int __init dmar_acpi_dev_scope_init(void)
+{
+       struct acpi_table_dmar *dmar;
+       struct dmar_res_callback cb = {
+               .print_entry = false,
+               .ignore_unhandled = true,
+               .cb[ACPI_DMAR_TYPE_NAMESPACE] = &__dmar_acpi_dev_scope_init,
+       };
 
        if (dmar_tbl == NULL)
                return -ENODEV;
 
-       for (andd = (void *)dmar_tbl + sizeof(struct acpi_table_dmar);
-            ((unsigned long)andd) < ((unsigned long)dmar_tbl) + 
dmar_tbl->length;
-            andd = ((void *)andd) + andd->header.length) {
-               if (andd->header.type == ACPI_DMAR_TYPE_NAMESPACE) {
-                       acpi_handle h;
-                       struct acpi_device *adev;
-
-                       if (!ACPI_SUCCESS(acpi_get_handle(ACPI_ROOT_OBJECT,
-                                                         andd->device_name,
-                                                         &h))) {
-                               pr_err("Failed to find handle for ACPI object 
%s\n",
-                                      andd->device_name);
-                               continue;
-                       }
-                       if (acpi_bus_get_device(h, &adev)) {
-                               pr_err("Failed to get device for ACPI object 
%s\n",
-                                      andd->device_name);
-                               continue;
-                       }
-                       dmar_acpi_insert_dev_scope(andd->device_number, adev);
-               }
-       }
-       return 0;
+       dmar = (struct acpi_table_dmar *)dmar_tbl;
+       return dmar_walk_dmar_table(dmar, &cb);
 }
 
 int __init dmar_dev_scope_init(void)
-- 
1.7.9.5