iommu/amd: Fix amd_iommu_free_device()
put_device_state_wait() doesn't loop on the condition and a spurious
wakeup will have it free the device state even though there might still
be references out to it.
Fix this by using 'normal' wait primitives.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 90f70d0..b6398d7 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -151,18 +151,6 @@
wake_up(&dev_state->wq);
}
-static void put_device_state_wait(struct device_state *dev_state)
-{
- DEFINE_WAIT(wait);
-
- prepare_to_wait(&dev_state->wq, &wait, TASK_UNINTERRUPTIBLE);
- if (!atomic_dec_and_test(&dev_state->count))
- schedule();
- finish_wait(&dev_state->wq, &wait);
-
- free_device_state(dev_state);
-}
-
/* Must be called under dev_state->lock */
static struct pasid_state **__get_pasid_state_ptr(struct device_state *dev_state,
int pasid, bool alloc)
@@ -851,7 +839,13 @@
/* Get rid of any remaining pasid states */
free_pasid_states(dev_state);
- put_device_state_wait(dev_state);
+ put_device_state(dev_state);
+ /*
+ * Wait until the last reference is dropped before freeing
+ * the device state.
+ */
+ wait_event(dev_state->wq, !atomic_read(&dev_state->count));
+ free_device_state(dev_state);
}
EXPORT_SYMBOL(amd_iommu_free_device);
