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| author | Peter Zijlstra <peterz@infradead.org> | 2015-02-03 13:25:51 +0100 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2015-02-04 15:33:36 +0100 |
| commit | 91f65facba5add493fffb643acdb258bd9f54eb2 (patch) | |
| tree | 7bebcccc51912a17e346d02a144852a0bf71b0dd | |
| parent | e36f014edff70fc02b3d3d79cead1d58f289332e (diff) | |
| download | linux-91f65facba5add493fffb643acdb258bd9f54eb2.tar.gz linux-91f65facba5add493fffb643acdb258bd9f54eb2.tar.bz2 linux-91f65facba5add493fffb643acdb258bd9f54eb2.zip | |
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>
| -rw-r--r-- | drivers/iommu/amd_iommu_v2.c | 20 |
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); |