[PATCH 10/10] iommu/vt-d: Misc macro clean up for SVM

Jacob Pan
2019-11-15T23:05:26Z

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>
---
drivers/iommu/intel-svm.c | 85 ++++++++++++++++++++++-------------------------
1 file changed, 40 insertions(+), 45 deletions(-)

diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index 189865501411..a7f67a9da3fc 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -226,6 +226,10 @@ 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, dev) \
+ list_for_each_entry(sdev, &svm->devs, list) \
+ if (dev != 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);
@@ -274,15 +278,13 @@ 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(sdev, svm, dev) {
+ if (sdev->ops != ops) {
+ ret = -EBUSY;
+ goto out;
}
+ sdev->users++;
+ goto success;
}

break;
@@ -427,45 +429,38 @@ int intel_svm_unbind_mm(struct device *dev, int pasid)
goto out;
}

- 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);
- kfree_rcu(sdev, rcu);
-
- if (list_empty(&svm->devs)) {
- /* Clear private data so that free pass check */
- ioasid_set_data(svm->pasid, NULL);
- 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)) {
+ /* Clear private data so that free pass check */
+ ioasid_set_data(svm->pasid, NULL);
+ 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