liquidio: improve soft command handling

1. Set LIO_SC_MAX_TMO_MS as the maximum timeout value for a soft command
   (sc).  All sc's use this value as a hard timeout value. Add expiry_time
   in struct octeon_soft_command to keep the hard timeout value. The field
   wait_time and timeout in struct octeon_soft_command will be obsoleted in
   the last patch of this patch series.
2. Add processing a synchronous sc in sc response thread
   lio_process_ordered_list. The memory allocated for a synchronous sc will
   be freed by lio_process_ordered_list() to the sc pool.
3. Add two response lists for lio_process_ordered_list to process the
   storage allocated for sc's:
   OCTEON_DONE_SC_LIST response list keeps all sc's which will be freed to
   the pool after their requestors have finished processing the responses.
   OCTEON_ZOMBIE_SC_LIST response list keeps all sc's which have got
   LIO_SC_MAX_TMO_MS timeout.
   When an sc gets a hard timeout, lio_process_order_list() will recheck
   its status 1 ms later. If the status has not updated by the firmware at
   that time, the sc will be removed from OCTEON_DONE_SC_LIST response list
   to OCTEON_ZOMBIE_SC_LIST response list. The sc's in the
   OCTEON_ZOMBIE_SC_LIST response list will be freed when the driver is
   unloaded.

Signed-off-by: Weilin Chang <weilin.chang@cavium.com>
Signed-off-by: Felix Manlunas <felix.manlunas@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 85 insertions, 29 deletions

diff --git a/drivers/net/ethernet/cavium/liquidio/request_manager.c b/drivers/net/ethernet/cavium/liquidio/request_manager.c
index 5de5ce9a8f54..bd0153e16deb 100644
--- a/drivers/net/ethernet/cavium/liquidio/request_manager.c
+++ b/drivers/net/ethernet/cavium/liquidio/request_manager.c
@@ -409,33 +409,22 @@ lio_process_iq_request_list(struct octeon_device *oct,
 			else
 				irh = (struct octeon_instr_irh *)
 					&sc->cmd.cmd2.irh;
-			if (irh->rflag) {
-				/* We're expecting a response from Octeon.
-				 * It's up to lio_process_ordered_list() to
-				 * process  sc. Add sc to the ordered soft
-				 * command response list because we expect
-				 * a response from Octeon.
-				 */
-				spin_lock_irqsave
-					(&oct->response_list
-					 [OCTEON_ORDERED_SC_LIST].lock,
-					 flags);
-				atomic_inc(&oct->response_list
-					[OCTEON_ORDERED_SC_LIST].
-					pending_req_count);
-				list_add_tail(&sc->node, &oct->response_list
-					[OCTEON_ORDERED_SC_LIST].head);
-				spin_unlock_irqrestore
-					(&oct->response_list
-					 [OCTEON_ORDERED_SC_LIST].lock,
-					 flags);
-			} else {
-				if (sc->callback) {
-					/* This callback must not sleep */
-					sc->callback(oct, OCTEON_REQUEST_DONE,
-						     sc->callback_arg);
-				}
-			}
+
+			/* We're expecting a response from Octeon.
+			 * It's up to lio_process_ordered_list() to
+			 * process  sc. Add sc to the ordered soft
+			 * command response list because we expect
+			 * a response from Octeon.
+			 */
+			spin_lock_irqsave(&oct->response_list
+					  [OCTEON_ORDERED_SC_LIST].lock, flags);
+			atomic_inc(&oct->response_list
+				   [OCTEON_ORDERED_SC_LIST].pending_req_count);
+			list_add_tail(&sc->node, &oct->response_list
+				[OCTEON_ORDERED_SC_LIST].head);
+			spin_unlock_irqrestore(&oct->response_list
+					       [OCTEON_ORDERED_SC_LIST].lock,
+					       flags);
 			break;
 		default:
 			dev_err(&oct->pci_dev->dev,
@@ -755,8 +744,7 @@ int octeon_send_soft_command(struct octeon_device *oct,
 		len = (u32)ih2->dlengsz;
 	}
 
-	if (sc->wait_time)
-		sc->timeout = jiffies + sc->wait_time;
+	sc->expiry_time = jiffies + msecs_to_jiffies(LIO_SC_MAX_TMO_MS);
 
 	return (octeon_send_command(oct, sc->iq_no, 1, &sc->cmd, sc,
 				    len, REQTYPE_SOFT_COMMAND));
@@ -791,11 +779,76 @@ int octeon_setup_sc_buffer_pool(struct octeon_device *oct)
 	return 0;
 }
 
+int octeon_free_sc_done_list(struct octeon_device *oct)
+{
+	struct octeon_response_list *done_sc_list, *zombie_sc_list;
+	struct octeon_soft_command *sc;
+	struct list_head *tmp, *tmp2;
+	spinlock_t *sc_lists_lock; /* lock for response_list */
+
+	done_sc_list = &oct->response_list[OCTEON_DONE_SC_LIST];
+	zombie_sc_list = &oct->response_list[OCTEON_ZOMBIE_SC_LIST];
+
+	if (!atomic_read(&done_sc_list->pending_req_count))
+		return 0;
+
+	sc_lists_lock = &oct->response_list[OCTEON_ORDERED_SC_LIST].lock;
+
+	spin_lock_bh(sc_lists_lock);
+
+	list_for_each_safe(tmp, tmp2, &done_sc_list->head) {
+		sc = list_entry(tmp, struct octeon_soft_command, node);
+
+		if (READ_ONCE(sc->caller_is_done)) {
+			list_del(&sc->node);
+			atomic_dec(&done_sc_list->pending_req_count);
+
+			if (*sc->status_word == COMPLETION_WORD_INIT) {
+				/* timeout; move sc to zombie list */
+				list_add_tail(&sc->node, &zombie_sc_list->head);
+				atomic_inc(&zombie_sc_list->pending_req_count);
+			} else {
+				octeon_free_soft_command(oct, sc);
+			}
+		}
+	}
+
+	spin_unlock_bh(sc_lists_lock);
+
+	return 0;
+}
+
+int octeon_free_sc_zombie_list(struct octeon_device *oct)
+{
+	struct octeon_response_list *zombie_sc_list;
+	struct octeon_soft_command *sc;
+	struct list_head *tmp, *tmp2;
+	spinlock_t *sc_lists_lock; /* lock for response_list */
+
+	zombie_sc_list = &oct->response_list[OCTEON_ZOMBIE_SC_LIST];
+	sc_lists_lock = &oct->response_list[OCTEON_ORDERED_SC_LIST].lock;
+
+	spin_lock_bh(sc_lists_lock);
+
+	list_for_each_safe(tmp, tmp2, &zombie_sc_list->head) {
+		list_del(tmp);
+		atomic_dec(&zombie_sc_list->pending_req_count);
+		sc = list_entry(tmp, struct octeon_soft_command, node);
+		octeon_free_soft_command(oct, sc);
+	}
+
+	spin_unlock_bh(sc_lists_lock);
+
+	return 0;
+}
+
 int octeon_free_sc_buffer_pool(struct octeon_device *oct)
 {
 	struct list_head *tmp, *tmp2;
 	struct octeon_soft_command *sc;
 
+	octeon_free_sc_zombie_list(oct);
+
 	spin_lock_bh(&oct->sc_buf_pool.lock);
 
 	list_for_each_safe(tmp, tmp2, &oct->sc_buf_pool.head) {
@@ -824,6 +877,9 @@ struct octeon_soft_command *octeon_alloc_soft_command(struct octeon_device *oct,
 	struct octeon_soft_command *sc = NULL;
 	struct list_head *tmp;
 
+	if (!rdatasize)
+		rdatasize = 16;
+
 	WARN_ON((offset + datasize + rdatasize + ctxsize) >
 	       SOFT_COMMAND_BUFFER_SIZE);