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authorPeter Zijlstra <peterz@infradead.org>2015-02-03 15:25:51 +0300
committerJoerg Roedel <jroedel@suse.de>2015-02-04 17:33:36 +0300
commit91f65facba5add493fffb643acdb258bd9f54eb2 (patch)
tree7bebcccc51912a17e346d02a144852a0bf71b0dd /drivers/iommu/amd_iommu_v2.c
parente36f014edff70fc02b3d3d79cead1d58f289332e (diff)
downloadlinux-91f65facba5add493fffb643acdb258bd9f54eb2.tar.xz
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>
Diffstat (limited to 'drivers/iommu/amd_iommu_v2.c')
-rw-r--r--drivers/iommu/amd_iommu_v2.c20
1 files changed, 7 insertions, 13 deletions
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 90f70d0e1141..b6398d7285f7 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -151,18 +151,6 @@ static void put_device_state(struct device_state *dev_state)
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 @@ void amd_iommu_free_device(struct pci_dev *pdev)
/* 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);