rpmsg: glink: Receive and store the remote intent buffers

Just like we allocating and sending intent ids to remote, remote side
allocates and sends us the intents as well.  So save the intent ids and
use it later while sending data targeting the appropriate intents based
on the size.
Acked-by: Arun Kumar Neelakantam <aneela@codeaurora.org>
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

drivers/rpmsg/qcom_glink_native.c

@@ -140,8 +140,9 @@ enum {
  * @name:	unique channel name/identifier
  * @lcid:	channel id, in local space
  * @rcid:	channel id, in remote space
- * @intent_lock: lock for protection of @liids
+ * @intent_lock: lock for protection of @liids, @riids
  * @liids:	idr of all local intents
+ * @riids:	idr of all remote intents
  * @intent_work: worker responsible for transmitting rx_done packets
  * @done_intents: list of intents that needs to be announced rx_done
  * @buf:	receive buffer, for gathering fragments
@@ -166,6 +167,7 @@ struct glink_channel {
 
 	spinlock_t intent_lock;
 	struct idr liids;
+	struct idr riids;
 	struct work_struct intent_work;
 	struct list_head done_intents;
 
@@ -223,6 +225,7 @@ static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 	INIT_WORK(&channel->intent_work, qcom_glink_rx_done_work);
 
 	idr_init(&channel->liids);
+	idr_init(&channel->riids);
 	kref_init(&channel->refcount);
 
 	return channel;
@@ -236,6 +239,7 @@ static void qcom_glink_channel_release(struct kref *ref)
 
 	spin_lock_irqsave(&channel->intent_lock, flags);
 	idr_destroy(&channel->liids);
+	idr_destroy(&channel->riids);
 	spin_unlock_irqrestore(&channel->intent_lock, flags);
 
 	kfree(channel->name);
@@ -807,6 +811,68 @@ static int qcom_glink_rx_data(struct qcom_glink *glink, size_t avail)
 	return ret;
 }
 
+static void qcom_glink_handle_intent(struct qcom_glink *glink,
+				     unsigned int cid,
+				     unsigned int count,
+				     size_t avail)
+{
+	struct glink_core_rx_intent *intent;
+	struct glink_channel *channel;
+	struct intent_pair {
+		__le32 size;
+		__le32 iid;
+	};
+
+	struct {
+		struct glink_msg msg;
+		struct intent_pair intents[];
+	} __packed * msg;
+
+	const size_t msglen = sizeof(*msg) + sizeof(struct intent_pair) * count;
+	int ret;
+	int i;
+	unsigned long flags;
+
+	if (avail < msglen) {
+		dev_dbg(glink->dev, "Not enough data in fifo\n");
+		return;
+	}
+
+	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, "intents for non-existing channel\n");
+		return;
+	}
+
+	msg = kmalloc(msglen, GFP_ATOMIC);
+	if (!msg)
+		return;
+
+	qcom_glink_rx_peak(glink, msg, 0, msglen);
+
+	for (i = 0; i < count; ++i) {
+		intent = kzalloc(sizeof(*intent), GFP_ATOMIC);
+		if (!intent)
+			break;
+
+		intent->id = le32_to_cpu(msg->intents[i].iid);
+		intent->size = le32_to_cpu(msg->intents[i].size);
+
+		spin_lock_irqsave(&channel->intent_lock, flags);
+		ret = idr_alloc(&channel->riids, intent,
+				intent->id, intent->id + 1, GFP_ATOMIC);
+		spin_unlock_irqrestore(&channel->intent_lock, flags);
+
+		if (ret < 0)
+			dev_err(glink->dev, "failed to store remote intent\n");
+	}
+
+	kfree(msg);
+	qcom_glink_rx_advance(glink, ALIGN(msglen, 8));
+}
+
 static int qcom_glink_rx_open_ack(struct qcom_glink *glink, unsigned int lcid)
 {
 	struct glink_channel *channel;
@@ -872,6 +938,9 @@ static irqreturn_t qcom_glink_native_intr(int irq, void *data)
 
 			ret = 0;
 			break;
+		case RPM_CMD_INTENT:
+			qcom_glink_handle_intent(glink, param1, param2, avail);
+			break;
 		default:
 			dev_err(glink->dev, "unhandled rx cmd: %d\n", cmd);
 			ret = -EINVAL;