[dpdk-dev] [PATCH v3 17/46] net/liquidio: add APIs for response list

[Shijith Thotton]

Add APIs to setup and process response list. Response list holds soft
commands waiting for response from device. Entries of this list are
processed to check for command response or timeout.

Signed-off-by: Shijith Thotton <shijith.thotton at caviumnetworks.com>
Signed-off-by: Jerin Jacob <jerin.jacob at caviumnetworks.com>
Signed-off-by: Derek Chickles <derek.chickles at caviumnetworks.com>
Signed-off-by: Venkat Koppula <venkat.koppula at caviumnetworks.com>
Signed-off-by: Srisivasubramanian S <ssrinivasan at caviumnetworks.com>
Signed-off-by: Mallesham Jatharakonda <mjatharakonda at oneconvergence.com>
---
 drivers/net/liquidio/lio_ethdev.c |   5 ++
 drivers/net/liquidio/lio_rxtx.c   | 106 ++++++++++++++++++++++++++++++++++++++
 drivers/net/liquidio/lio_rxtx.h   |  73 ++++++++++++++++++++++++++
 drivers/net/liquidio/lio_struct.h |  14 +++++
 4 files changed, 198 insertions(+)

diff --git a/drivers/net/liquidio/lio_ethdev.c b/drivers/net/liquidio/lio_ethdev.c
index a1dcdf6..97a7369 100644
--- a/drivers/net/liquidio/lio_ethdev.c
+++ b/drivers/net/liquidio/lio_ethdev.c
@@ -107,6 +107,11 @@
 		return -1;
 	}
 
+	/* Initialize lists to manage the requests of different types that
+	 * arrive from applications for this lio device.
+	 */
+	lio_setup_response_list(lio_dev);
+
 	if (lio_dev->fn_list.setup_mbox(lio_dev)) {
 		lio_dev_err(lio_dev, "Mailbox setup failed\n");
 		goto error;
diff --git a/drivers/net/liquidio/lio_rxtx.c b/drivers/net/liquidio/lio_rxtx.c
index cfec96d..c61397f 100644
--- a/drivers/net/liquidio/lio_rxtx.c
+++ b/drivers/net/liquidio/lio_rxtx.c
@@ -293,3 +293,109 @@ struct lio_soft_command *
 {
 	rte_pktmbuf_free(sc->mbuf);
 }
+
+void
+lio_setup_response_list(struct lio_device *lio_dev)
+{
+	STAILQ_INIT(&lio_dev->response_list.head);
+	rte_spinlock_init(&lio_dev->response_list.lock);
+	rte_atomic64_set(&lio_dev->response_list.pending_req_count, 0);
+}
+
+int
+lio_process_ordered_list(struct lio_device *lio_dev)
+{
+	int resp_to_process = LIO_MAX_ORD_REQS_TO_PROCESS;
+	struct lio_response_list *ordered_sc_list;
+	struct lio_soft_command *sc;
+	int request_complete = 0;
+	uint64_t status64;
+	uint32_t status;
+
+	ordered_sc_list = &lio_dev->response_list;
+
+	do {
+		rte_spinlock_lock(&ordered_sc_list->lock);
+
+		if (STAILQ_EMPTY(&ordered_sc_list->head)) {
+			/* ordered_sc_list is empty; there is
+			 * nothing to process
+			 */
+			rte_spinlock_unlock(&ordered_sc_list->lock);
+			return -1;
+		}
+
+		sc = LIO_STQUEUE_FIRST_ENTRY(&ordered_sc_list->head,
+					     struct lio_soft_command, node);
+
+		status = LIO_REQUEST_PENDING;
+
+		/* check if octeon has finished DMA'ing a response
+		 * to where rptr is pointing to
+		 */
+		status64 = *sc->status_word;
+
+		if (status64 != LIO_COMPLETION_WORD_INIT) {
+			/* This logic ensures that all 64b have been written.
+			 * 1. check byte 0 for non-FF
+			 * 2. if non-FF, then swap result from BE to host order
+			 * 3. check byte 7 (swapped to 0) for non-FF
+			 * 4. if non-FF, use the low 32-bit status code
+			 * 5. if either byte 0 or byte 7 is FF, don't use status
+			 */
+			if ((status64 & 0xff) != 0xff) {
+				lio_swap_8B_data(&status64, 1);
+				if (((status64 & 0xff) != 0xff)) {
+					/* retrieve 16-bit firmware status */
+					status = (uint32_t)(status64 &
+							    0xffffULL);
+					if (status) {
+						status =
+						LIO_FIRMWARE_STATUS_CODE(
+									status);
+					} else {
+						/* i.e. no error */
+						status = LIO_REQUEST_DONE;
+					}
+				}
+			}
+		} else if ((sc->timeout && lio_check_timeout(lio_uptime,
+							     sc->timeout))) {
+			lio_dev_err(lio_dev,
+				    "cmd failed, timeout (%ld, %ld)\n",
+				    (long)lio_uptime, (long)sc->timeout);
+			status = LIO_REQUEST_TIMEOUT;
+		}
+
+		if (status != LIO_REQUEST_PENDING) {
+			/* we have received a response or we have timed out.
+			 * remove node from linked list
+			 */
+			STAILQ_REMOVE(&ordered_sc_list->head,
+				      &sc->node, lio_stailq_node, entries);
+			rte_atomic64_dec(
+			    &lio_dev->response_list.pending_req_count);
+			rte_spinlock_unlock(&ordered_sc_list->lock);
+
+			if (sc->callback)
+				sc->callback(status, sc->callback_arg);
+
+			request_complete++;
+		} else {
+			/* no response yet */
+			request_complete = 0;
+			rte_spinlock_unlock(&ordered_sc_list->lock);
+		}
+
+		/* If we hit the Max Ordered requests to process every loop,
+		 * we quit and let this function be invoked the next time
+		 * the poll thread runs to process the remaining requests.
+		 * This function can take up the entire CPU if there is
+		 * no upper limit to the requests processed.
+		 */
+		if (request_complete >= resp_to_process)
+			break;
+	} while (request_complete);
+
+	return 0;
+}
diff --git a/drivers/net/liquidio/lio_rxtx.h b/drivers/net/liquidio/lio_rxtx.h
index 284cb18..0e7eb6a 100644
--- a/drivers/net/liquidio/lio_rxtx.h
+++ b/drivers/net/liquidio/lio_rxtx.h
@@ -42,6 +42,14 @@
 
 #include "lio_struct.h"
 
+#define LIO_STQUEUE_FIRST_ENTRY(ptr, type, elem)	\
+	(type *)((char *)((ptr)->stqh_first) - offsetof(type, elem))
+
+#define lio_check_timeout(cur_time, chk_time) ((cur_time) > (chk_time))
+
+#define lio_uptime		\
+	(size_t)(rte_get_timer_cycles() / rte_get_timer_hz())
+
 struct lio_request_list {
 	uint32_t reqtype;
 	void *buf;
@@ -94,6 +102,71 @@ struct lio_soft_command *
 		       uint32_t ctxsize);
 void lio_free_soft_command(struct lio_soft_command *sc);
 
+/** Maximum ordered requests to process in every invocation of
+ *  lio_process_ordered_list(). The function will continue to process requests
+ *  as long as it can find one that has finished processing. If it keeps
+ *  finding requests that have completed, the function can run for ever. The
+ *  value defined here sets an upper limit on the number of requests it can
+ *  process before it returns control to the poll thread.
+ */
+#define LIO_MAX_ORD_REQS_TO_PROCESS	4096
+
+/** Error codes used in Octeon Host-Core communication.
+ *
+ *   31		16 15		0
+ *   ----------------------------
+ * |		|		|
+ *   ----------------------------
+ *   Error codes are 32-bit wide. The upper 16-bits, called Major Error Number,
+ *   are reserved to identify the group to which the error code belongs. The
+ *   lower 16-bits, called Minor Error Number, carry the actual code.
+ *
+ *   So error codes are (MAJOR NUMBER << 16)| MINOR_NUMBER.
+ */
+/** Status for a request.
+ *  If the request is successfully queued, the driver will return
+ *  a LIO_REQUEST_PENDING status. LIO_REQUEST_TIMEOUT is only returned by
+ *  the driver if the response for request failed to arrive before a
+ *  time-out period or if the request processing * got interrupted due to
+ *  a signal respectively.
+ */
+enum {
+	/** A value of 0x00000000 indicates no error i.e. success */
+	LIO_REQUEST_DONE	= 0x00000000,
+	/** (Major number: 0x0000; Minor Number: 0x0001) */
+	LIO_REQUEST_PENDING	= 0x00000001,
+	LIO_REQUEST_TIMEOUT	= 0x00000003,
+
+};
+
+/*------ Error codes used by firmware (bits 15..0 set by firmware */
+#define LIO_FIRMWARE_MAJOR_ERROR_CODE	 0x0001
+#define LIO_FIRMWARE_STATUS_CODE(status) \
+	((LIO_FIRMWARE_MAJOR_ERROR_CODE << 16) | (status))
+
+/** Initialize the response lists. The number of response lists to create is
+ *  given by count.
+ *  @param lio_dev - the lio device structure.
+ */
+void lio_setup_response_list(struct lio_device *lio_dev);
+
+/** Check the status of first entry in the ordered list. If the instruction at
+ *  that entry finished processing or has timed-out, the entry is cleaned.
+ *  @param lio_dev - the lio device structure.
+ *  @return 1 if the ordered list is empty, 0 otherwise.
+ */
+int lio_process_ordered_list(struct lio_device *lio_dev);
+
+static inline void
+lio_swap_8B_data(uint64_t *data, uint32_t blocks)
+{
+	while (blocks) {
+		*data = rte_cpu_to_be_64(*data);
+		blocks--;
+		data++;
+	}
+}
+
 /** Setup instruction queue zero for the device
  *  @param lio_dev which lio device to setup
  *
diff --git a/drivers/net/liquidio/lio_struct.h b/drivers/net/liquidio/lio_struct.h
index 45f9ac9..add0e7d 100644
--- a/drivers/net/liquidio/lio_struct.h
+++ b/drivers/net/liquidio/lio_struct.h
@@ -213,6 +213,17 @@ struct lio_sriov_info {
 	uint32_t num_vfs;
 };
 
+/* Head of a response list */
+struct lio_response_list {
+	/** List structure to add delete pending entries to */
+	struct lio_stailq_head head;
+
+	/** A lock for this response list */
+	rte_spinlock_t lock;
+
+	rte_atomic64_t pending_req_count;
+};
+
 /* Structure to define the configuration attributes for each Input queue. */
 struct lio_iq_config {
 	/* Max number of IQs available */
@@ -289,6 +300,9 @@ struct lio_device {
 	/** The input instruction queues */
 	struct lio_instr_queue *instr_queue[LIO_MAX_POSSIBLE_INSTR_QUEUES];
 
+	/** The singly-linked tail queues of instruction response */
+	struct lio_response_list response_list;
+
 	struct lio_io_enable io_qmask;
 
 	struct lio_sriov_info sriov_info;
-- 
1.8.3.1