[PATCH v3 13/16] iommu/vt-d: Clean up for SVM device list

Jacob Pan
2019-05-03T22:31:13Z

Use combined macro for_each_svm_dev() to simplify SVM device iteration.

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>
---
drivers/iommu/intel-svm.c | 79 +++++++++++++++++++++++------------------------
1 file changed, 39 insertions(+), 40 deletions(-)

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 8fff212..068dd9e 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -227,6 +227,9 @@ static const struct mmu_notifier_ops intel_mmuops = {

static DEFINE_MUTEX(pasid_mutex);
static LIST_HEAD(global_svm_list);
+#define for_each_svm_dev() \
+ list_for_each_entry(sdev, &svm->devs, list) \
+ if (dev == sdev->dev) \

int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_ops *ops)
{
@@ -273,15 +276,13 @@ 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;
+ for_each_svm_dev() {
+ if (sdev->ops != ops) {
+ ret = -EBUSY;
+ goto out;
}
+ sdev->users++;
+ goto success;
}

break;
@@ -411,40 +412,38 @@ int intel_svm_unbind_mm(struct device *dev, int pasid)
if (!svm)
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, !svm->mm);
- 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() {
+ 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, !svm->mm);
+ 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);
--
2.7.4