Smatch static checker warns:
        drivers/iommu/amd/iommu_v2.c:133 free_device_state()
        warn: sleeping in atomic context

Fixes by storing the list of struct device_state in a temporary
list, and then free the memory after releasing the spinlock.

Reported-by: Dan Carpenter <[email protected]>
Fixes: dc6a709e5123 ("iommu/amd: Improve amd_iommu_v2_exit()")
Signed-off-by: Suravee Suthikulpanit <[email protected]>
---
 drivers/iommu/amd/iommu_v2.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/amd/iommu_v2.c b/drivers/iommu/amd/iommu_v2.c
index 490da41c3c71..5a6e4f87d875 100644
--- a/drivers/iommu/amd/iommu_v2.c
+++ b/drivers/iommu/amd/iommu_v2.c
@@ -947,6 +947,7 @@ static void __exit amd_iommu_v2_exit(void)
 {
        struct device_state *dev_state, *next;
        unsigned long flags;
+       LIST_HEAD(freelist);
 
        if (!amd_iommu_v2_supported())
                return;
@@ -966,11 +967,20 @@ static void __exit amd_iommu_v2_exit(void)
 
                put_device_state(dev_state);
                list_del(&dev_state->list);
-               free_device_state(dev_state);
+               list_add_tail(&dev_state->list, &freelist);
        }
 
        spin_unlock_irqrestore(&state_lock, flags);
 
+       /*
+        * Since free_device_state waits on the count to be zero,
+        * we need to free dev_state outside the spinlock.
+        */
+       list_for_each_entry_safe(dev_state, next, &freelist, list) {
+               list_del(&dev_state->list);
+               free_device_state(dev_state);
+       }
+
        destroy_workqueue(iommu_wq);
 }
 
-- 
2.17.1

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