iommu/vt-d: Introduce macro for_each_dev_scope() to walk device scope entries

Introduce for_each_dev_scope()/for_each_active_dev_scope() to walk
{active} device scope entries. This will help following RCU lock
related patches.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

1 files changed, 9 insertions, 5 deletions

diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c
index 58dde75c5229..4ae6df27ad5d 100644
--- a/drivers/iommu/dmar.c
+++ b/drivers/iommu/dmar.c
@@ -170,9 +170,12 @@ int __init dmar_parse_dev_scope(void *start, void *end, int *cnt,
 
 void dmar_free_dev_scope(struct pci_dev ***devices, int *cnt)
 {
+        int i;
+        struct pci_dev *tmp_dev;
+
         if (*devices && *cnt) {
-                while (--*cnt >= 0)
-                        pci_dev_put((*devices)[*cnt]);
+                for_each_active_dev_scope(*devices, *cnt, i, tmp_dev)
+                        pci_dev_put(tmp_dev);
                 kfree(*devices);
                 *devices = NULL;
                 *cnt = 0;
@@ -402,10 +405,11 @@ static int dmar_pci_device_match(struct pci_dev *devices[], int cnt,
                           struct pci_dev *dev)
 {
         int index;
+        struct pci_dev *tmp;
 
         while (dev) {
-                for (index = 0; index < cnt; index++)
-                        if (dev == devices[index])
+                for_each_active_dev_scope(devices, cnt, index, tmp)
+                        if (dev == tmp)
                                 return 1;
 
                 /* Check our parent */
@@ -452,7 +456,7 @@ int __init dmar_dev_scope_init(void)
         if (list_empty(&dmar_drhd_units))
                 goto fail;
 
-        list_for_each_entry(drhd, &dmar_drhd_units, list) {
+        for_each_drhd_unit(drhd) {
                 ret = dmar_parse_dev(drhd);
                 if (ret)
                         goto fail;