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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>
This commit is contained in:
Peter Zijlstra 2015-02-03 13:25:51 +01:00 committed by Joerg Roedel
parent e36f014edf
commit 91f65facba
1 changed files with 7 additions and 13 deletions
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20
drivers/iommu/amd_iommu_v2.c
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@ -151,18 +151,6 @@ static void put_device_state(struct device_state *dev_state)
wake_up(&dev_state->wq); 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 */ /* Must be called under dev_state->lock */
static struct pasid_state **__get_pasid_state_ptr(struct device_state *dev_state, static struct pasid_state **__get_pasid_state_ptr(struct device_state *dev_state,
int pasid, bool alloc) int pasid, bool alloc)
@ -851,7 +839,13 @@ void amd_iommu_free_device(struct pci_dev *pdev)
/* Get rid of any remaining pasid states */ /* Get rid of any remaining pasid states */
free_pasid_states(dev_state); 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); EXPORT_SYMBOL(amd_iommu_free_device);