1 files changed, 38 insertions, 31 deletions

diff --git a/drivers/dma/idxd/submit.c b/drivers/dma/idxd/submit.c
index 83452fbbb168..e289fd48711a 100644
--- a/drivers/dma/idxd/submit.c
+++ b/drivers/dma/idxd/submit.c
@@ -21,15 +21,6 @@ static struct idxd_desc *__get_desc(struct idxd_wq *wq, int idx, int cpu)
 	if (device_pasid_enabled(idxd))
 		desc->hw->pasid = idxd->pasid;
 
-	/*
-	 * On host, MSIX vecotr 0 is used for misc interrupt. Therefore when we match
-	 * vector 1:1 to the WQ id, we need to add 1
-	 */
-	if (!idxd->int_handles)
-		desc->hw->int_handle = wq->id + 1;
-	else
-		desc->hw->int_handle = idxd->int_handles[wq->id];
-
 	return desc;
 }
 
@@ -134,35 +125,58 @@ static void llist_abort_desc(struct idxd_wq *wq, struct idxd_irq_entry *ie,
 	spin_unlock(&ie->list_lock);
 
 	if (found)
-		complete_desc(found, IDXD_COMPLETE_ABORT);
+		idxd_dma_complete_txd(found, IDXD_COMPLETE_ABORT, false);
 
 	/*
-	 * complete_desc() will return desc to allocator and the desc can be
-	 * acquired by a different process and the desc->list can be modified.
-	 * Delete desc from list so the list trasversing does not get corrupted
-	 * by the other process.
+	 * completing the descriptor will return desc to allocator and
+	 * the desc can be acquired by a different process and the
+	 * desc->list can be modified.  Delete desc from list so the
+	 * list trasversing does not get corrupted by the other process.
 	 */
 	list_for_each_entry_safe(d, t, &flist, list) {
 		list_del_init(&d->list);
-		complete_desc(d, IDXD_COMPLETE_NORMAL);
+		idxd_dma_complete_txd(found, IDXD_COMPLETE_ABORT, true);
 	}
 }
 
+/*
+ * ENQCMDS typically fail when the WQ is inactive or busy. On host submission, the driver
+ * has better control of number of descriptors being submitted to a shared wq by limiting
+ * the number of driver allocated descriptors to the wq size. However, when the swq is
+ * exported to a guest kernel, it may be shared with multiple guest kernels. This means
+ * the likelihood of getting busy returned on the swq when submitting goes significantly up.
+ * Having a tunable retry mechanism allows the driver to keep trying for a bit before giving
+ * up. The sysfs knob can be tuned by the system administrator.
+ */
+int idxd_enqcmds(struct idxd_wq *wq, void __iomem *portal, const void *desc)
+{
+	int rc, retries = 0;
+
+	do {
+		rc = enqcmds(portal, desc);
+		if (rc == 0)
+			break;
+		cpu_relax();
+	} while (retries++ < wq->enqcmds_retries);
+
+	return rc;
+}
+
 int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
 {
 	struct idxd_device *idxd = wq->idxd;
 	struct idxd_irq_entry *ie = NULL;
+	u32 desc_flags = desc->hw->flags;
 	void __iomem *portal;
 	int rc;
 
-	if (idxd->state != IDXD_DEV_ENABLED) {
-		idxd_free_desc(wq, desc);
+	if (idxd->state != IDXD_DEV_ENABLED)
 		return -EIO;
-	}
 
 	if (!percpu_ref_tryget_live(&wq->wq_active)) {
-		idxd_free_desc(wq, desc);
-		return -ENXIO;
+		wait_for_completion(&wq->wq_resurrect);
+		if (!percpu_ref_tryget_live(&wq->wq_active))
+			return -ENXIO;
 	}
 
 	portal = idxd_wq_portal_addr(wq);
@@ -178,28 +192,21 @@ int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
 	 * Pending the descriptor to the lockless list for the irq_entry
 	 * that we designated the descriptor to.
 	 */
-	if (desc->hw->flags & IDXD_OP_FLAG_RCI) {
-		ie = &idxd->irq_entries[wq->id + 1];
+	if (desc_flags & IDXD_OP_FLAG_RCI) {
+		ie = &wq->ie;
+		desc->hw->int_handle = ie->int_handle;
 		llist_add(&desc->llnode, &ie->pending_llist);
 	}
 
 	if (wq_dedicated(wq)) {
 		iosubmit_cmds512(portal, desc->hw, 1);
 	} else {
-		/*
-		 * It's not likely that we would receive queue full rejection
-		 * since the descriptor allocation gates at wq size. If we
-		 * receive a -EAGAIN, that means something went wrong such as the
-		 * device is not accepting descriptor at all.
-		 */
-		rc = enqcmds(portal, desc->hw);
+		rc = idxd_enqcmds(wq, portal, desc->hw);
 		if (rc < 0) {
 			percpu_ref_put(&wq->wq_active);
 			/* abort operation frees the descriptor */
 			if (ie)
 				llist_abort_desc(wq, ie, desc);
-			else
-				idxd_free_desc(wq, desc);
 			return rc;
 		}
 	}