rpmsg updates for v4.16

This fixes a few issues found in the SMD and GLINK drivers and corrects the
 handling of SMD channels that are found in an (previously) unexpected state.
 -----BEGIN PGP SIGNATURE-----
 Version: GnuPG v1
 
 iQIcBAABAgAGBQJaeJV5AAoJEAsfOT8Nma3FN8YP/1UjlQmor7yTeWUg37nordmy
 ELjpNdjhBI6570XbeUdtBLi5LZLdYxkAxqt2J67YdnBkyL+EedlYS3tto7Rupo0e
 P/kLokPJ6I+6FxwKftBi27mt8uyNdIx2nXXof2QhnjtVvXChoOj4e3BEi9KTfuMk
 1LPOjldIXHN8ORibcYT5beEcyhZKdOJIsgC5qVsxJ27sLtFPVT9YHpSVVUPZIqO8
 EAmSMUqzwCOaiOoEztl29izobYfBH2zR1wvLkq6TWyJXT9uhzkMuyBALbEzwzdBz
 pgOm1YadEL8rHoSc2TI1sOGAfsQLxHN2h2/QwSeMeRGI1bF7w1EEmjlTKJkDdUug
 +1om6t8XL08oodrCnkltSF2GGhVHaNOkdm0+sYySsWr6fPDAGO8rd4SimzMr1+9J
 xIhOBeFfj4Q1xlreVgvvGPlJu1UBaJO9xK8bNShNy3irRLLRKObIAy9RkKfVD+qq
 sW7xjjsDZ94rSSVGq7vs041ozBZKwa67YBn3eRuZvRHJqKyfVVIGduNx5Ld28qJJ
 0Au8a4+g7fxXA0NdxYhwmHGOVEi7pb39U4aREzlJjy4fw1dGlTaEOCfjTXG2DRhs
 TOuCpn2Rr9fbWjDDXUUEVQCNl8R3IoQfqUDF1VyXdPrGVeDtQvFgn9rlQFPZirt6
 b184EJEuQCylkMTRqwV3
 =J7N0
 -----END PGP SIGNATURE-----

Merge tag 'rpmsg-v4.16' of git://github.com/andersson/remoteproc

Pull rpmsg updates from Bjorn Andersson:
 "This fixes a few issues found in the SMD and GLINK drivers and
  corrects the handling of SMD channels that are found in an
  (previously) unexpected state"

* tag 'rpmsg-v4.16' of git://github.com/andersson/remoteproc:
  rpmsg: smd: Fix double unlock in __qcom_smd_send()
  rpmsg: glink: Fix missing mutex_init() in qcom_glink_alloc_channel()
  rpmsg: smd: Don't hold the tx lock during wait
  rpmsg: smd: Fail send on a closed channel
  rpmsg: smd: Wake up all waiters
  rpmsg: smd: Create device for all channels
  rpmsg: smd: Perform handshake during open
  rpmsg: glink: smem: Ensure ordering during tx
  drivers: rpmsg: remove duplicate includes
  remoteproc: qcom: Use PTR_ERR_OR_ZERO() in glink prob

drivers/remoteproc/qcom_common.c

@@ -57,7 +57,7 @@ static int glink_subdev_probe(struct rproc_subdev *subdev)
 
 	glink->edge = qcom_glink_smem_register(glink->dev, glink->node);
 
-	return IS_ERR(glink->edge) ? PTR_ERR(glink->edge) : 0;
+	return PTR_ERR_OR_ZERO(glink->edge);
 }
 
 static void glink_subdev_remove(struct rproc_subdev *subdev)

drivers/rpmsg/qcom_glink_native.c

@@ -221,6 +221,7 @@ static struct glink_channel *qcom_glink_alloc_channel(struct qcom_glink *glink,
 	/* Setup glink internal glink_channel data */
 	spin_lock_init(&channel->recv_lock);
 	spin_lock_init(&channel->intent_lock);
+	mutex_init(&channel->intent_req_lock);
 
 	channel->glink = glink;
 	channel->name = kstrdup(name, GFP_KERNEL);

drivers/rpmsg/qcom_glink_smem.c

@@ -29,8 +29,6 @@
 #include <linux/workqueue.h>
 #include <linux/list.h>
 
-#include <linux/delay.h>
-#include <linux/rpmsg.h>
 #include <linux/rpmsg/qcom_glink.h>
 
 #include "qcom_glink_native.h"
@@ -185,6 +183,9 @@ static void glink_smem_tx_write(struct qcom_glink_pipe *glink_pipe,
 	if (head >= pipe->native.length)
 		head -= pipe->native.length;
 
+	/* Ensure ordering of fifo and head update */
+	wmb();
+
 	*pipe->head = cpu_to_le32(head);
 }
 

drivers/rpmsg/qcom_smd.c

@@ -200,6 +200,7 @@ struct qcom_smd_channel {
 	char *name;
 	enum smd_channel_state state;
 	enum smd_channel_state remote_state;
+	wait_queue_head_t state_change_event;
 
 	struct smd_channel_info_pair *info;
 	struct smd_channel_info_word_pair *info_word;
@@ -570,13 +571,15 @@ static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel)
 	if (remote_state != channel->remote_state) {
 		channel->remote_state = remote_state;
 		need_state_scan = true;
+
+		wake_up_interruptible_all(&channel->state_change_event);
 	}
 	/* Indicate that we have seen any state change */
 	SET_RX_CHANNEL_FLAG(channel, fSTATE, 0);
 
 	/* Signal waiting qcom_smd_send() about the interrupt */
 	if (!GET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR))
-		wake_up_interruptible(&channel->fblockread_event);
+		wake_up_interruptible_all(&channel->fblockread_event);
 
 	/* Don't consume any data until we've opened the channel */
 	if (channel->state != SMD_CHANNEL_OPENED)
@@ -740,28 +743,37 @@ static int __qcom_smd_send(struct qcom_smd_channel *channel, const void *data,
 	if (ret)
 		return ret;
 
-	while (qcom_smd_get_tx_avail(channel) < tlen) {
+	while (qcom_smd_get_tx_avail(channel) < tlen &&
+	       channel->state == SMD_CHANNEL_OPENED) {
 		if (!wait) {
 			ret = -EAGAIN;
-			goto out;
-		}
-
-		if (channel->state != SMD_CHANNEL_OPENED) {
-			ret = -EPIPE;
-			goto out;
+			goto out_unlock;
 		}
 
 		SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0);
 
+		/* Wait without holding the tx_lock */
+		mutex_unlock(&channel->tx_lock);
+
 		ret = wait_event_interruptible(channel->fblockread_event,
 				       qcom_smd_get_tx_avail(channel) >= tlen ||
 				       channel->state != SMD_CHANNEL_OPENED);
 		if (ret)
-			goto out;
+			return ret;
+
+		ret = mutex_lock_interruptible(&channel->tx_lock);
+		if (ret)
+			return ret;
 
 		SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1);
 	}
 
+	/* Fail if the channel was closed */
+	if (channel->state != SMD_CHANNEL_OPENED) {
+		ret = -EPIPE;
+		goto out_unlock;
+	}
+
 	SET_TX_CHANNEL_FLAG(channel, fTAIL, 0);
 
 	qcom_smd_write_fifo(channel, hdr, sizeof(hdr));
@@ -774,7 +786,7 @@ static int __qcom_smd_send(struct qcom_smd_channel *channel, const void *data,
 
 	qcom_smd_signal_channel(channel);
 
-out:
+out_unlock:
 	mutex_unlock(&channel->tx_lock);
 
 	return ret;
@@ -786,7 +798,9 @@ out:
 static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
 				 rpmsg_rx_cb_t cb)
 {
+	struct qcom_smd_edge *edge = channel->edge;
 	size_t bb_size;
+	int ret;
 
 	/*
 	 * Packets are maximum 4k, but reduce if the fifo is smaller
@@ -798,9 +812,33 @@ static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
 
 	qcom_smd_channel_set_callback(channel, cb);
 	qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
+
+	/* Wait for remote to enter opening or opened */
+	ret = wait_event_interruptible_timeout(channel->state_change_event,
+			channel->remote_state == SMD_CHANNEL_OPENING ||
+			channel->remote_state == SMD_CHANNEL_OPENED,
+			HZ);
+	if (!ret) {
+		dev_err(&edge->dev, "remote side did not enter opening state\n");
+		goto out_close_timeout;
+	}
+
 	qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
 
+	/* Wait for remote to enter opened */
+	ret = wait_event_interruptible_timeout(channel->state_change_event,
+			channel->remote_state == SMD_CHANNEL_OPENED,
+			HZ);
+	if (!ret) {
+		dev_err(&edge->dev, "remote side did not enter open state\n");
+		goto out_close_timeout;
+	}
+
 	return 0;
+
+out_close_timeout:
+	qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
+	return -ETIMEDOUT;
 }
 
 /*
@@ -1055,6 +1093,7 @@ static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *ed
 	mutex_init(&channel->tx_lock);
 	spin_lock_init(&channel->recv_lock);
 	init_waitqueue_head(&channel->fblockread_event);
+	init_waitqueue_head(&channel->state_change_event);
 
 	info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size);
 	if (IS_ERR(info)) {
@@ -1161,7 +1200,7 @@ static void qcom_channel_scan_worker(struct work_struct *work)
 			dev_dbg(&edge->dev, "new channel found: '%s'\n", channel->name);
 			set_bit(i, edge->allocated[tbl]);
 
-			wake_up_interruptible(&edge->new_channel_event);
+			wake_up_interruptible_all(&edge->new_channel_event);
 		}
 	}
 
@@ -1195,11 +1234,6 @@ static void qcom_channel_state_worker(struct work_struct *work)
 		if (channel->state != SMD_CHANNEL_CLOSED)
 			continue;
 
-		remote_state = GET_RX_CHANNEL_INFO(channel, state);
-		if (remote_state != SMD_CHANNEL_OPENING &&
-		    remote_state != SMD_CHANNEL_OPENED)
-			continue;
-
 		if (channel->registered)
 			continue;