nvme: add I/O timeout callback

Change-Id: Ie6220590467b88fe1e63b4b0f8a01221fc0c1206
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>

include/spdk/nvme.h

@@ -381,6 +381,28 @@ void spdk_nvme_ctrlr_register_aer_callback(struct spdk_nvme_ctrlr *ctrlr,
  */
 struct spdk_nvme_qpair;
 
+/**
+ * Signature for the callback function invoked when a timeout is
+ * detected on a request.
+ */
+typedef void (*spdk_nvme_timeout_cb)(struct spdk_nvme_ctrlr *ctrlr,
+				     struct spdk_nvme_qpair *qpair,
+				     void *cb_arg);
+
+/**
+ * \brief Register for timeout callback on a controller.
+ *
+ * The application can choose to register for timeout callback or not register
+ * for timeout callback.
+ *
+ * \param ctrlr NVMe controller on which to monitor for timeout.
+ * \param timeout_sec Timeout value in seconds.
+ * \param cb_fn A function pointer that points to the callback function
+ * \param cb_arg Argument to the callback function.
+ */
+void spdk_nvme_ctrlr_register_timeout_callback(struct spdk_nvme_ctrlr *ctrlr,
+		uint32_t timeout_sec, spdk_nvme_timeout_cb cb_fn, void *cb_arg);
+
 /**
  * \brief Allocate an I/O queue pair (submission and completion queue).
  *

lib/nvme/nvme_ctrlr.c

@@ -1299,6 +1299,9 @@ nvme_ctrlr_construct(struct spdk_nvme_ctrlr *ctrlr)
 	}
 
 	TAILQ_INIT(&ctrlr->active_procs);
+	ctrlr->timeout_cb_fn = NULL;
+	ctrlr->timeout_cb_arg = NULL;
+	ctrlr->timeout_ticks = 0;
 
 	return rc;
 }
@@ -1430,6 +1433,15 @@ spdk_nvme_ctrlr_register_aer_callback(struct spdk_nvme_ctrlr *ctrlr,
 	ctrlr->aer_cb_arg = aer_cb_arg;
 }
 
+void
+spdk_nvme_ctrlr_register_timeout_callback(struct spdk_nvme_ctrlr *ctrlr,
+		uint32_t nvme_timeout, spdk_nvme_timeout_cb cb_fn, void *cb_arg)
+{
+	ctrlr->timeout_ticks = nvme_timeout * spdk_get_ticks_hz();
+	ctrlr->timeout_cb_fn = cb_fn;
+	ctrlr->timeout_cb_arg = cb_arg;
+}
+
 bool
 spdk_nvme_ctrlr_is_log_page_supported(struct spdk_nvme_ctrlr *ctrlr, uint8_t log_page)
 {

lib/nvme/nvme_internal.h

@@ -411,6 +411,13 @@ struct spdk_nvme_ctrlr {
 
 	/** Track all the processes manage this controller */
 	TAILQ_HEAD(, spdk_nvme_ctrlr_process)	active_procs;
+
+	/**
+	 * A function pointer to timeout callback function
+	 */
+	spdk_nvme_timeout_cb		timeout_cb_fn;
+	void				*timeout_cb_arg;
+	uint64_t			timeout_ticks;
 };
 
 struct nvme_driver {

lib/nvme/nvme_pcie.c

@@ -121,14 +121,13 @@ struct nvme_tracker {
 
 	uint32_t			rsvd2;
 
+	uint64_t			timeout_tick;
 	uint64_t			prp_sgl_bus_addr;
 
 	union {
 		uint64_t			prp[NVME_MAX_PRP_LIST_ENTRIES];
 		struct spdk_nvme_sgl_descriptor	sgl[NVME_MAX_SGL_DESCRIPTORS];
 	} u;
-
-	uint64_t			rsvd3;
 };
 /*
  * struct nvme_tracker must be exactly 4K so that the prp[] array does not cross a page boundary
@@ -933,6 +932,8 @@ nvme_pcie_qpair_submit_tracker(struct spdk_nvme_qpair *qpair, struct nvme_tracke
 	struct nvme_pcie_qpair	*pqpair = nvme_pcie_qpair(qpair);
 	struct nvme_pcie_ctrlr	*pctrlr = nvme_pcie_ctrlr(qpair->ctrlr);
 
+	tr->timeout_tick = spdk_get_ticks() + qpair->ctrlr->timeout_ticks;
+
 	req = tr->req;
 	pqpair->tr[tr->cid].active = true;
 
@@ -1725,6 +1726,44 @@ exit:
 	return rc;
 }
 
+static void
+nvme_pcie_qpair_check_timeout(struct spdk_nvme_qpair *qpair)
+{
+	uint64_t t02;
+	struct nvme_tracker *tr;
+	struct nvme_pcie_qpair *pqpair = nvme_pcie_qpair(qpair);
+	struct spdk_nvme_ctrlr *ctrlr = qpair->ctrlr;
+
+	if (TAILQ_EMPTY(&pqpair->outstanding_tr)) {
+		return;
+	}
+
+	/*
+	 * qpair could be either for normal i/o or for admin command. If qpair is admin
+	 * and request is SPDK_NVME_OPC_ASYNC_EVENT_REQUEST, skip to next previous.
+	 */
+	tr = TAILQ_LAST(&pqpair->outstanding_tr, nvme_outstanding_tr_head);
+	while (tr->req->cmd.opc == SPDK_NVME_OPC_ASYNC_EVENT_REQUEST) {
+		/* qpair is for admin request */
+		tr = TAILQ_PREV(tr, nvme_outstanding_tr_head, tq_list);
+		if (!tr) {
+			/*
+			 * All request were AER
+			 */
+			return;
+		}
+	}
+
+	t02 = spdk_get_ticks();
+	if (tr->timeout_tick <= t02) {
+		/*
+		 * Request has timed out. This could be i/o or admin request.
+		 * Call the registered timeout function for user to take action.
+		 */
+		ctrlr->timeout_cb_fn(ctrlr, qpair, ctrlr->timeout_cb_arg);
+	}
+}
+
 int32_t
 nvme_pcie_qpair_process_completions(struct spdk_nvme_qpair *qpair, uint32_t max_completions)
 {
@@ -1791,6 +1830,15 @@ nvme_pcie_qpair_process_completions(struct spdk_nvme_qpair *qpair, uint32_t max_
 		g_thread_mmio_ctrlr = NULL;
 	}
 
+	if (qpair->ctrlr->state == NVME_CTRLR_STATE_READY) {
+		if (qpair->ctrlr->timeout_cb_fn) {
+			/*
+			 * User registered for timeout callback
+			 */
+			nvme_pcie_qpair_check_timeout(qpair);
+		}
+	}
+
 	/* Before returning, complete any pending admin request. */
 	if (nvme_qpair_is_admin_queue(qpair)) {
 		nvme_pcie_qpair_complete_pending_admin_request(qpair);