[PATCH v2 19/20] rpmsg: glink: Request for intents when unavailable

Sricharan R
2017-08-24T07:23:02Z

While sending data, we search for suitable sized
intent to map and simply fail if a intent is not
found. Instead request for a intent of required
size and wait till one is alloted.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
drivers/rpmsg/qcom_glink_native.c | 76 +++++++++++++++++++++++++++++++++++++--
1 file changed, 74 insertions(+), 2 deletions(-)

diff --git a/drivers/rpmsg/qcom_glink_native.c b/drivers/rpmsg/qcom_glink_native.c
index 163c082..54ddb66 100644
--- a/drivers/rpmsg/qcom_glink_native.c
+++ b/drivers/rpmsg/qcom_glink_native.c
@@ -149,6 +149,9 @@ enum {
* @buf_size: size of current @buf
* @open_ack: completed once remote has acked the open-request
* @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
*/
struct glink_channel {
struct rpmsg_endpoint ept;
@@ -176,6 +179,10 @@ struct glink_channel {

struct completion open_ack;
struct completion open_req;
+
+ struct mutex intent_req_lock;
+ bool intent_req_result;
+ struct completion intent_req_comp;
};

#define to_glink_channel(_ept) container_of(_ept, struct glink_channel, ept)
@@ -342,6 +349,24 @@ static void qcom_glink_send_open_ack(struct qcom_glink *glink,
qcom_glink_tx(glink, &msg, sizeof(msg), NULL, 0, true);
}

+static void qcom_glink_handle_intent_req_ack(struct qcom_glink *glink,
+ unsigned int cid, bool granted)
+{
+ struct glink_channel *channel;
+ unsigned long flags;
+
+ spin_lock_irqsave(&glink->idr_lock, flags);
+ channel = idr_find(&glink->rcids, cid);
+ spin_unlock_irqrestore(&glink->idr_lock, flags);
+ if (!channel) {
+ dev_err(glink->dev, "unable to find channel\n");
+ return;
+ }
+
+ channel->intent_req_result = granted;
+ complete(&channel->intent_req_comp);
+}
+
/**
* qcom_glink_send_open_req() - send a RPM_CMD_OPEN request to the remote
* @glink: Ptr to the glink edge
@@ -940,6 +965,10 @@ static irqreturn_t qcom_glink_native_intr(int irq, void *data)
case RPM_CMD_INTENT:
qcom_glink_handle_intent(glink, param1, param2, avail);
break;
+ case RPM_CMD_RX_INTENT_REQ_ACK:
+ qcom_glink_handle_intent_req_ack(glink, param1, param2);
+ qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
+ break;
default:
qcom_glink_rx_advance(glink, ALIGN(sizeof(msg), 8));
dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
@@ -1106,6 +1135,42 @@ static void qcom_glink_destroy_ept(struct rpmsg_endpoint *ept)
qcom_glink_send_close_req(glink, channel);
}

+static int qcom_glink_request_intent(struct qcom_glink *glink,
+ struct glink_channel *channel,
+ size_t size)
+{
+ struct {
+ u16 id;
+ u16 cid;
+ u32 size;
+ } __packed cmd;
+
+ int ret;
+
+ mutex_lock(&channel->intent_req_lock);
+
+ reinit_completion(&channel->intent_req_comp);
+
+ cmd.id = RPM_CMD_RX_INTENT_REQ;
+ cmd.cid = channel->lcid;
+ cmd.size = size;
+
+ ret = qcom_glink_tx(glink, &cmd, sizeof(cmd), NULL, 0, true);
+ if (ret)
+ return ret;
+
+ ret = wait_for_completion_timeout(&channel->intent_req_comp, 10 * HZ);
+ if (!ret) {
+ dev_err(glink->dev, "intent request timed out\n");
+ ret = -ETIMEDOUT;
+ } else {
+ ret = channel->intent_req_result ? 0 : -ECANCELED;
+ }
+
+ mutex_unlock(&channel->intent_req_lock);
+ return ret;
+}
+
static int __qcom_glink_send(struct glink_channel *channel,
void *data, int len, bool wait)
{
@@ -1122,7 +1187,7 @@ static int __qcom_glink_send(struct glink_channel *channel,
unsigned long flags;

if (!glink->intentless) {
- if (!intent) {
+ while (!intent) {
spin_lock_irqsave(&channel->intent_lock, flags);
idr_for_each_entry(&channel->riids, tmp, iid) {
if (tmp->size >= len && !tmp->in_use) {
@@ -1134,8 +1199,15 @@ static int __qcom_glink_send(struct glink_channel *channel,
spin_unlock_irqrestore(&channel->intent_lock, flags);

/* We found an available intent */
- if (!intent)
+ if (intent)
+ break;
+
+ if (!wait)
return -EBUSY;
+
+ ret = qcom_glink_request_intent(glink, channel, len);
+ if (ret < 0)
+ return ret;
}

iid = intent->id;