Hi,
On 10/25/19 3:55 AM, Jacob Pan wrote:
Use combined macros for_each_svm_dev() to simplify SVM device iteration
and error checking.
Suggested-by: Andy Shevchenko <[email protected]>
Signed-off-by: Jacob Pan <[email protected]>
Reviewed-by: Eric Auger <[email protected]>
---
drivers/iommu/intel-svm.c | 89 ++++++++++++++++++++++-------------------------
1 file changed, 42 insertions(+), 47 deletions(-)
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
index a9a7f85a09bc..a18b02a9709d 100644
--- a/drivers/iommu/intel-svm.c
+++ b/drivers/iommu/intel-svm.c
@@ -212,6 +212,10 @@ static const struct mmu_notifier_ops intel_mmuops = {
static DEFINE_MUTEX(pasid_mutex);
static LIST_HEAD(global_svm_list);
+#define for_each_svm_dev(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)
{
struct intel_iommu *iommu = intel_svm_device_to_iommu(dev);
@@ -257,15 +261,13 @@ 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(svm, dev) {
+ if (sdev->ops != ops) {
+ ret = -EBUSY;
+ goto out;
}
+ sdev->users++;
+ goto success;
}
break;
@@ -402,50 +404,43 @@ int intel_svm_unbind_mm(struct device *dev, int pasid)
goto out;
svm = ioasid_find(NULL, pasid, NULL);
- if (IS_ERR(svm)) {
+ if (IS_ERR_OR_NULL(svm)) {
ret = PTR_ERR(svm);
goto out;
}
- if (!svm)
- goto out;
If svm == NULL here, this function will return success. This isn't
expected, right?
Others looks good to me.
Reviewed-by: Lu Baolu <[email protected]>
Best regards,
baolu
-
- 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(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);
@@ -581,7 +576,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)
* to unbind the mm while any page faults are
outstanding.
* So we only need RCU to protect the internal idr
code. */
rcu_read_unlock();
- if (IS_ERR(svm) || !svm) {
+ if (IS_ERR_OR_NULL(svm)) {
pr_err("%s: Page request for invalid PASID %d:
%08llx %08llx\n",
iommu->name, req->pasid, ((unsigned long
long *)req)[0],
((unsigned long long *)req)[1]);
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