[dpdk-dev] [PATCH 20/50] net/liquidio: add APIs for response list

[Shijith Thotton]

Add API to setup and process response list. It is used to wait for
response from device.

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: 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 3702c61..a6813e0 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..515ba79 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)
+{
+	CIRCLEQ_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 (CIRCLEQ_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_CLIST_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
+			 */
+			CIRCLEQ_REMOVE(&ordered_sc_list->head,
+				       &sc->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 8dab73e..58e2a6e 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_CLIST_FIRST_ENTRY(ptr, type, elem)	\
+	(type *)((char *)((ptr)->cqh_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 a06726b..ad67ed1 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_clist_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 circular-linked list 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