rpmsg: glink: Transition intent request signaling to wait queue

Transition the intent request acknowledgement to use a wait queue so
that it's possible, in the next commit, to extend the wait to also wait
for an incoming intent.

Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
Reviewed-by: Chris Lew <quic_clew@quicinc.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230327144617.3134175-2-quic_bjorande@quicinc.com

diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
index 01d2805..0b6291f 100644 (file)
--- a/drivers/rpmsg/qcom_glink_native.c
+++ b/drivers/rpmsg/qcom_glink_native.c
@@ -16,6 +16,7 @@
 #include <linux/rpmsg.h>
 #include <linux/sizes.h>
 #include <linux/slab.h>
+#include <linux/wait.h>
 #include <linux/workqueue.h>
 #include <linux/mailbox_client.h>
 
@@ -145,7 +146,7 @@ enum {
  * @open_req:  completed once open-request has been received
  * @intent_req_lock: Synchronises multiple intent requests
  * @intent_req_result: Result of intent request
- * @intent_req_comp: Completion for intent_req signalling
+ * @intent_req_wq: wait queue for intent_req signalling
  */
 struct glink_channel {
        struct rpmsg_endpoint ept;
@@ -175,8 +176,8 @@ struct glink_channel {
        struct completion open_req;
 
        struct mutex intent_req_lock;
-       bool intent_req_result;
-       struct completion intent_req_comp;
+       int intent_req_result;
+       wait_queue_head_t intent_req_wq;
 };
 
 #define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
@@ -221,7 +222,7 @@ static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 
        init_completion(&channel->open_req);
        init_completion(&channel->open_ack);
-       init_completion(&channel->intent_req_comp);
+       init_waitqueue_head(&channel->intent_req_wq);
 
        INIT_LIST_HEAD(&channel->done_intents);
        INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
@@ -420,13 +421,13 @@ static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
        }
 
        channel->intent_req_result = granted;
-       complete(&channel->intent_req_comp);
+       wake_up_all(&channel->intent_req_wq);
 }
 
 static void qcom_glink_intent_req_abort(struct glink_channel *channel)
 {
        channel->intent_req_result = 0;
-       complete(&channel->intent_req_comp);
+       wake_up_all(&channel->intent_req_wq);
 }
 
 /**
@@ -1271,7 +1272,7 @@ static int qcom_glink_request_intent(struct qcom_glink *glink,
 
        mutex_lock(&channel->intent_req_lock);
 
-       reinit_completion(&channel->intent_req_comp);
+       WRITE_ONCE(channel->intent_req_result, -1);
 
        cmd.id = GLINK_CMD_RX_INTENT_REQ;
        cmd.cid = channel->lcid;
@@ -1281,12 +1282,14 @@ static int qcom_glink_request_intent(struct qcom_glink *glink,
        if (ret)
                goto unlock;
 
-       ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
+       ret = wait_event_timeout(channel->intent_req_wq,
+                                READ_ONCE(channel->intent_req_result) >= 0,
+                                10 * HZ);
        if (!ret) {
                dev_err(glink->dev, "intent request timed out\n");
                ret = -ETIMEDOUT;
        } else {
-               ret = channel->intent_req_result ? 0 : -ECANCELED;
+               ret = READ_ONCE(channel->intent_req_result) ? 0 : -ECANCELED;
        }
 
 unlock: