Merge branch 'for-5.16-vsprintf-pgp' into for-linus

1 files changed, 12 insertions, 7 deletions

diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 4b9b3f35ba0e..0c228787704f 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -31,8 +31,6 @@ static irqreturn_t prq_event_thread(int irq, void *d);
 static void intel_svm_drain_prq(struct device *dev, u32 pasid);
 #define to_intel_svm_dev(handle) container_of(handle, struct intel_svm_dev, sva)
 
-#define PRQ_ORDER 0
-
 static DEFINE_XARRAY_ALLOC(pasid_private_array);
 static int pasid_private_add(ioasid_t pasid, void *priv)
 {
@@ -516,9 +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);
 
@@ -725,8 +720,6 @@ struct page_req_dsc {
 	u64 priv_data[2];
 };
 
-#define PRQ_RING_MASK	((0x1000 << PRQ_ORDER) - 0x20)
-
 static bool is_canonical_address(u64 addr)
 {
 	int shift = 64 - (__VIRTUAL_MASK_SHIFT + 1);
@@ -796,7 +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