ipmi/bt: Enable adding messages to the start of the queue

By default new ipmi messages are added to the end of the transmission
queue. However sometimes it is necessary to add messages to the start
of the queue. This patch adds a new ipmi function that adds messages
to the start of the transmission queue.

Signed-off-by: Alistair Popple <alistair@popple.id.au>
Signed-off-by: Stewart Smith <stewart@linux.vnet.ibm.com>

1 files changed, 23 insertions, 5 deletions

diff --git a/hw/bt.c b/hw/bt.c
index 355cc93..afdd5df 100644
--- a/hw/bt.c
+++ b/hw/bt.c
@@ -374,14 +374,10 @@ static void bt_poll(struct timer *t __unused, void *data __unused)
 		       bt.irq_ok ? TIMER_POLL : msecs_to_tb(BT_DEFAULT_POLL_MS));
 }
 
-static int bt_add_ipmi_msg(struct ipmi_msg *ipmi_msg)
+static void bt_add_msg(struct bt_msg *bt_msg)
 {
-	struct bt_msg *bt_msg = container_of(ipmi_msg, struct bt_msg, ipmi_msg);
-
-	lock(&bt.msgq_lock);
 	bt_msg->tb = 0;
 	bt_msg->seq = ipmi_seq++;
-	list_add_tail(&bt.msgq, &bt_msg->link);
 	bt.queue_len++;
 	if (bt.queue_len > BT_MAX_QUEUE_LEN) {
 		/* Maximum ueue lenght exceeded - remove the oldest message
@@ -391,10 +387,31 @@ static int bt_add_ipmi_msg(struct ipmi_msg *ipmi_msg)
 		assert(bt_msg);
 		bt_msg_del(bt_msg);
 	}
+}
+
+static int bt_add_ipmi_msg_head(struct ipmi_msg *ipmi_msg)
+{
+	struct bt_msg *bt_msg = container_of(ipmi_msg, struct bt_msg, ipmi_msg);
+
+	lock(&bt.msgq_lock);
+	bt_add_msg(bt_msg);
+	list_add(&bt.msgq, &bt_msg->link);
 	unlock(&bt.msgq_lock);
 
 	bt_poll(NULL, NULL);
+	return 0;
+}
+
+static int bt_add_ipmi_msg(struct ipmi_msg *ipmi_msg)
+{
+	struct bt_msg *bt_msg = container_of(ipmi_msg, struct bt_msg, ipmi_msg);
 
+	lock(&bt.msgq_lock);
+	bt_add_msg(bt_msg);
+	list_add_tail(&bt.msgq, &bt_msg->link);
+	unlock(&bt.msgq_lock);
+
+	bt_poll(NULL, NULL);
 	return 0;
 }
 
@@ -459,6 +476,7 @@ struct ipmi_backend bt_backend = {
 	.alloc_msg = bt_alloc_ipmi_msg,
 	.free_msg = bt_free_ipmi_msg,
 	.queue_msg = bt_add_ipmi_msg,
+	.queue_msg_head = bt_add_ipmi_msg_head,
 	.dequeue_msg = bt_del_ipmi_msg,
 };