iommu/vt-d: Misc macro clean up for SVM

Use combined macros for_each_svm_dev() to simplify SVM device iteration
and error checking.

Suggested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 7c6a6e8..0402303 100644 (file)
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -222,6 +222,10 @@ static const struct mmu_notifier_ops intel_mmuops = {
 static DEFINE_MUTEX(pasid_mutex);
 static LIST_HEAD(global_svm_list);
 
+#define for_each_svm_dev(sdev, svm, d)                 \
+       list_for_each_entry((sdev), &(svm)->devs, list) \
+               if ((d) != (sdev)->dev) {} else
+
 int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ops *ops)
 {
        struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
@@ -270,15 +274,14 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
                                goto out;
                        }
 
-                       list_for_each_entry(sdev, &svm->devs, list) {
-                               if (dev == sdev->dev) {
-                                       if (sdev->ops != ops) {
-                                               ret = -EBUSY;
-                                               goto out;
-                                       }
-                                       sdev->users++;
-                                       goto success;
+                       /* Find the matching device in svm list */
+                       for_each_svm_dev(sdev, svm, dev) {
+                               if (sdev->ops != ops) {
+                                       ret = -EBUSY;
+                                       goto out;
                                }
+                               sdev->users++;
+                               goto success;
                        }
 
                        break;
@@ -423,40 +426,36 @@ int intel_svm_unbind_mm(struct device *dev, int pasid)
                goto out;
        }
 
-       list_for_each_entry(sdev, &svm->devs, list) {
-               if (dev == sdev->dev) {
-                       ret = 0;
-                       sdev->users--;
-                       if (!sdev->users) {
-                               list_del_rcu(&sdev->list);
-                               /* Flush the PASID cache and IOTLB for this device.
-                                * Note that we do depend on the hardware *not* using
-                                * the PASID any more. Just as we depend on other
-                                * devices never using PASIDs that they have no right
-                                * to use. We have a *shared* PASID table, because it's
-                                * large and has to be physically contiguous. So it's
-                                * hard to be as defensive as we might like. */
-                               intel_pasid_tear_down_entry(iommu, dev, svm->pasid);
-                               intel_flush_svm_range_dev(svm, sdev, 0, -1, 0);
-                               kfree_rcu(sdev, rcu);
-
-                               if (list_empty(&svm->devs)) {
-                                       ioasid_free(svm->pasid);
-                                       if (svm->mm)
-                                               mmu_notifier_unregister(&svm->notifier, svm->mm);
-
-                                       list_del(&svm->list);
-
-                                       /* We mandate that no page faults may be outstanding
-                                        * for the PASID when intel_svm_unbind_mm() is called.
-                                        * If that is not obeyed, subtle errors will happen.
-                                        * Let's make them less subtle... */
-                                       memset(svm, 0x6b, sizeof(*svm));
-                                       kfree(svm);
-                               }
+       for_each_svm_dev(sdev, svm, dev) {
+               ret = 0;
+               sdev->users--;
+               if (!sdev->users) {
+                       list_del_rcu(&sdev->list);
+                       /* Flush the PASID cache and IOTLB for this device.
+                        * Note that we do depend on the hardware *not* using
+                        * the PASID any more. Just as we depend on other
+                        * devices never using PASIDs that they have no right
+                        * to use. We have a *shared* PASID table, because it's
+                        * large and has to be physically contiguous. So it's
+                        * hard to be as defensive as we might like. */
+                       intel_pasid_tear_down_entry(iommu, dev, svm->pasid);
+                       intel_flush_svm_range_dev(svm, sdev, 0, -1, 0);
+                       kfree_rcu(sdev, rcu);
+
+                       if (list_empty(&svm->devs)) {
+                               ioasid_free(svm->pasid);
+                               if (svm->mm)
+                                       mmu_notifier_unregister(&svm->notifier, svm->mm);
+                               list_del(&svm->list);
+                               /* We mandate that no page faults may be outstanding
+                                * for the PASID when intel_svm_unbind_mm() is called.
+                                * If that is not obeyed, subtle errors will happen.
+                                * Let's make them less subtle... */
+                               memset(svm, 0x6b, sizeof(*svm));
+                               kfree(svm);
                        }
-                       break;
                }
+               break;
        }
  out:
        mutex_unlock(&pasid_mutex);