diff options
Diffstat (limited to 'drivers/iommu/intel/svm.c')
| -rw-r--r-- | drivers/iommu/intel/svm.c | 15 |
1 files changed, 12 insertions, 3 deletions
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c index 2014fe8695ac..0c228787704f 100644 --- a/drivers/iommu/intel/svm.c +++ b/drivers/iommu/intel/svm.c @@ -514,9 +514,6 @@ static void load_pasid(struct mm_struct *mm, u32 pasid) { mutex_lock(&mm->context.lock); - /* Synchronize with READ_ONCE in update_pasid(). */ - smp_store_release(&mm->pasid, pasid); - /* Update PASID MSR on all CPUs running the mm's tasks. */ on_each_cpu_mask(mm_cpumask(mm), _load_pasid, NULL, true); @@ -792,7 +789,19 @@ prq_retry: goto prq_retry; } + /* + * A work in IO page fault workqueue may try to lock pasid_mutex now. + * Holding pasid_mutex while waiting in iopf_queue_flush_dev() for + * all works in the workqueue to finish may cause deadlock. + * + * It's unnecessary to hold pasid_mutex in iopf_queue_flush_dev(). + * Unlock it to allow the works to be handled while waiting for + * them to finish. + */ + lockdep_assert_held(&pasid_mutex); + mutex_unlock(&pasid_mutex); iopf_queue_flush_dev(dev); + mutex_lock(&pasid_mutex); /* * Perform steps described in VT-d spec CH7.10 to drain page |