Merge tag 'rpmsg-v7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux

Pull rpmsg updates from Bjorn Andersson:

 - Allow virtio rpmsg to use separate transmit and receive buffer counts
   based on the vring sizes, and obtain buffer sizes from virtio config
   space when the feature is negotiated. Document the configuration and
   report the MTU in the sample driver.

 - Fix signal interruption and timeout handling while waiting for a
   virtio transmit buffer. Release the device tree node reference on
   MediaTek channel teardown.

 - Convert the rpmsg control ioctl comments to kernel-doc format.

* tag 'rpmsg-v7.4' of git://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux:
  rpmsg: virtio: fix error handling in TX buffer wait
  rpmsg: mtk: release channel OF node on device teardown
  samples: rpmsg: Fix mtu printk specifiers
  samples: rpmsg: Add MTU size info
  docs: rpmsg: Add virtio config space details
  rpmsg: virtio_rpmsg_bus: Get buffer size from config space
  rpmsg: virtio_rpmsg_bus: Allow different size of tx and rx bufs
  rpmsg: virtio_rpmsg_bus: Rename rbufs and sbufs
  rpmsg: ctrl: use kernel-doc format for ioctl macros

2 files changed, 114 insertions, 48 deletions

diff --git a/drivers/rpmsg/mtk_rpmsg.c b/drivers/rpmsg/mtk_rpmsg.c
index 1b670ed54cfa..430a9b2aa7bb 100644
--- a/drivers/rpmsg/mtk_rpmsg.c
+++ b/drivers/rpmsg/mtk_rpmsg.c
@@ -168,6 +168,7 @@ static void mtk_rpmsg_release_device(struct device *dev)
 	struct rpmsg_device *rpdev = to_rpmsg_device(dev);
 	struct mtk_rpmsg_device *mdev = to_mtk_rpmsg_device(rpdev);
 
+	of_node_put(dev->of_node);
 	kfree(mdev);
 }
 
diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
index 1b8bb05924af..23ff6c8b7a20 100644
--- a/drivers/rpmsg/virtio_rpmsg_bus.c
+++ b/drivers/rpmsg/virtio_rpmsg_bus.c
@@ -20,6 +20,7 @@
 #include <linux/rpmsg.h>
 #include <linux/rpmsg/byteorder.h>
 #include <linux/rpmsg/ns.h>
+#include <linux/rpmsg/virtio_rpmsg.h>
 #include <linux/scatterlist.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
@@ -35,13 +36,15 @@
  * @vdev:	the virtio device
  * @rvq:	rx virtqueue
  * @svq:	tx virtqueue
- * @rbufs:	kernel address of rx buffers
- * @sbufs:	kernel address of tx buffers
- * @num_bufs:	total number of buffers for rx and tx
- * @buf_size:   size of one rx or tx buffer
- * @last_sbuf:	index of last tx buffer used
+ * @rx_bufs:	kernel address of rx buffers
+ * @tx_bufs:	kernel address of tx buffers
+ * @num_rx_buf: total number of rx buffers
+ * @num_tx_buf: total number of tx buffers
+ * @rx_buf_size: size of one rx buffer
+ * @tx_buf_size: size of one tx buffer
+ * @last_tx_buf: index of last tx buffer used
  * @bufs_dma:	dma base addr of the buffers
- * @tx_lock:	protects svq and sbufs, to allow concurrent senders.
+ * @tx_lock:	protects svq and tx_bufs, to allow concurrent senders.
  *		sending a message might require waking up a dozing remote
  *		processor, which involves sleeping, hence the mutex.
  * @endpoints:	idr of local endpoints, allows fast retrieval
@@ -55,10 +58,12 @@
 struct virtproc_info {
 	struct virtio_device *vdev;
 	struct virtqueue *rvq, *svq;
-	void *rbufs, *sbufs;
-	unsigned int num_bufs;
-	unsigned int buf_size;
-	int last_sbuf;
+	void *rx_bufs, *tx_bufs;
+	unsigned int num_rx_buf;
+	unsigned int num_tx_buf;
+	unsigned int rx_buf_size;
+	unsigned int tx_buf_size;
+	int last_tx_buf;
 	dma_addr_t bufs_dma;
 	struct mutex tx_lock;
 	struct idr endpoints;
@@ -66,9 +71,6 @@ struct virtproc_info {
 	wait_queue_head_t sendq;
 };
 
-/* The feature bitmap for virtio rpmsg */
-#define VIRTIO_RPMSG_F_NS	0 /* RP supports name service notifications */
-
 /**
  * struct rpmsg_hdr - common header for all rpmsg messages
  * @src: source address
@@ -110,7 +112,7 @@ struct virtio_rpmsg_channel {
 /*
  * We're allocating buffers of 512 bytes each for communications. The
  * number of buffers will be computed from the number of buffers supported
- * by the vring, upto a maximum of 512 buffers (256 in each direction).
+ * by the vring, up to a maximum of 256 in each direction.
  *
  * Each buffer will have 16 bytes for the msg header and 496 bytes for
  * the payload.
@@ -125,8 +127,8 @@ struct virtio_rpmsg_channel {
  * can change this without changing anything in the firmware of the remote
  * processor.
  */
-#define MAX_RPMSG_NUM_BUFS	(512)
-#define MAX_RPMSG_BUF_SIZE	(512)
+#define MAX_RPMSG_NUM_BUFS	(256)
+#define DEFAULT_RPMSG_BUF_SIZE	(512)
 
 /*
  * Local addresses are dynamically allocated on-demand.
@@ -439,12 +441,9 @@ static void *get_a_tx_buf(struct virtproc_info *vrp)
 
 	mutex_lock(&vrp->tx_lock);
 
-	/*
-	 * either pick the next unused tx buffer
-	 * (half of our buffers are used for sending messages)
-	 */
-	if (vrp->last_sbuf < vrp->num_bufs / 2)
-		ret = vrp->sbufs + vrp->buf_size * vrp->last_sbuf++;
+	/* either pick the next unused tx buffer */
+	if (vrp->last_tx_buf < vrp->num_tx_buf)
+		ret = vrp->tx_bufs + vrp->tx_buf_size * vrp->last_tx_buf++;
 	/* or recycle a used one */
 	else
 		ret = virtqueue_get_buf(vrp->svq, &len);
@@ -514,7 +513,7 @@ static int rpmsg_send_offchannel_raw(struct rpmsg_device *rpdev,
 	 * messaging), or to improve the buffer allocator, to support
 	 * variable-length buffer sizes.
 	 */
-	if (len > vrp->buf_size - sizeof(struct rpmsg_hdr)) {
+	if (len > vrp->tx_buf_size - sizeof(struct rpmsg_hdr)) {
 		dev_err(dev, "message is too big (%d)\n", len);
 		return -EMSGSIZE;
 	}
@@ -536,10 +535,13 @@ static int rpmsg_send_offchannel_raw(struct rpmsg_device *rpdev,
 					(msg = get_a_tx_buf(vrp)),
 					msecs_to_jiffies(15000));
 
+		if (err < 0)
+			return err;
+
 		/* timeout ? */
 		if (!err) {
 			dev_err(dev, "timeout waiting for a tx buffer\n");
-			return -ERESTARTSYS;
+			return -ETIMEDOUT;
 		}
 	}
 
@@ -630,11 +632,10 @@ static __poll_t virtio_rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,
 
 	/*
 	 * check for a free buffer, either:
-	 * - we haven't used all of the available transmit buffers (half of the
-	 *   allocated buffers are used for transmit, hence num_bufs / 2), or,
+	 * - we haven't used all of the available transmit buffers or,
 	 * - we ask the virtqueue if there's a buffer available
 	 */
-	if (vrp->last_sbuf < vrp->num_bufs / 2 ||
+	if (vrp->last_tx_buf < vrp->num_tx_buf ||
 	    !virtqueue_enable_cb(vrp->svq))
 		mask |= EPOLLOUT;
 
@@ -648,7 +649,7 @@ static ssize_t virtio_rpmsg_get_mtu(struct rpmsg_endpoint *ept)
 	struct rpmsg_device *rpdev = ept->rpdev;
 	struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);
 
-	return vch->vrp->buf_size - sizeof(struct rpmsg_hdr);
+	return vch->vrp->tx_buf_size - sizeof(struct rpmsg_hdr);
 }
 
 static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,
@@ -674,7 +675,7 @@ static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,
 	 * We currently use fixed-sized buffers, so trivially sanitize
 	 * the reported payload length.
 	 */
-	if (len > vrp->buf_size ||
+	if (len > vrp->rx_buf_size ||
 	    msg_len > (len - sizeof(struct rpmsg_hdr))) {
 		dev_warn(dev, "inbound msg too big: (%d, %d)\n", len, msg_len);
 		return -EINVAL;
@@ -707,7 +708,7 @@ static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,
 		dev_warn_ratelimited(dev, "msg received with no recipient\n");
 
 	/* publish the real size of the buffer */
-	rpmsg_sg_init(&sg, msg, vrp->buf_size);
+	rpmsg_sg_init(&sg, msg, vrp->rx_buf_size);
 
 	/* add the buffer back to the remote processor's virtqueue */
 	err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, msg, GFP_KERNEL);
@@ -811,6 +812,65 @@ static void rpmsg_virtio_del_ctrl_dev(struct rpmsg_device *rpdev_ctrl)
 	device_unregister(&rpdev_ctrl->dev);
 }
 
+static int rpmsg_virtio_get_buf_size(struct virtproc_info *vrp)
+{
+	struct virtio_device *vdev;
+	u8 version;
+	u16 size;
+
+	vdev = vrp->vdev;
+
+	/*
+	 * If VIRTIO_RPMSG_F_BUFSZ feature is supported, then configure buf
+	 * size from virtio device config space from the resource table.
+	 * If the feature is not supported, then assign default buf size.
+	 */
+	if (virtio_has_feature(vdev, VIRTIO_RPMSG_F_BUFSZ)) {
+		virtio_cread(vdev, struct virtio_rpmsg_config,
+			     version, &version);
+
+		/* for now we support only v1 */
+		if (version != RPMSG_VDEV_CONFIG_V1) {
+			dev_err(&vdev->dev,
+				"unsupported vdev config version %u\n", version);
+			return -EINVAL;
+		}
+
+		/* size of the config space must match */
+		virtio_cread(vdev, struct virtio_rpmsg_config,
+			     size, &size);
+		if (size != sizeof(struct virtio_rpmsg_config)) {
+			dev_err(&vdev->dev, "invalid size of vdev config %u\n",
+				size);
+			return -EINVAL;
+		}
+
+		/* note: tx and rx are defined from remote view */
+		virtio_cread(vdev, struct virtio_rpmsg_config,
+			     txbuf_size, &vrp->rx_buf_size);
+		virtio_cread(vdev, struct virtio_rpmsg_config,
+			     rxbuf_size, &vrp->tx_buf_size);
+
+		/* The buffers must hold at least the rpmsg header */
+		if (vrp->rx_buf_size < sizeof(struct rpmsg_hdr) ||
+		    vrp->tx_buf_size < sizeof(struct rpmsg_hdr)) {
+			dev_err(&vdev->dev,
+				"bad vdev config: rx buf sz = %u, tx buf sz = %u\n",
+				vrp->rx_buf_size, vrp->tx_buf_size);
+			return -EINVAL;
+		}
+
+		dev_dbg(&vdev->dev,
+			"vdev config: ver=%u, rx sz = 0x%x, tx sz = 0x%x\n",
+			version, vrp->rx_buf_size, vrp->tx_buf_size);
+	} else {
+		vrp->rx_buf_size = DEFAULT_RPMSG_BUF_SIZE;
+		vrp->tx_buf_size = DEFAULT_RPMSG_BUF_SIZE;
+	}
+
+	return 0;
+}
+
 static int rpmsg_probe(struct virtio_device *vdev)
 {
 	struct virtqueue_info vqs_info[] = {
@@ -845,19 +905,23 @@ static int rpmsg_probe(struct virtio_device *vdev)
 	vrp->rvq = vqs[0];
 	vrp->svq = vqs[1];
 
-	/* we expect symmetric tx/rx vrings */
-	WARN_ON(virtqueue_get_vring_size(vrp->rvq) !=
-		virtqueue_get_vring_size(vrp->svq));
-
 	/* we need less buffers if vrings are small */
-	if (virtqueue_get_vring_size(vrp->rvq) < MAX_RPMSG_NUM_BUFS / 2)
-		vrp->num_bufs = virtqueue_get_vring_size(vrp->rvq) * 2;
+	if (virtqueue_get_vring_size(vrp->rvq) < MAX_RPMSG_NUM_BUFS)
+		vrp->num_rx_buf = virtqueue_get_vring_size(vrp->rvq);
+	else
+		vrp->num_rx_buf = MAX_RPMSG_NUM_BUFS;
+
+	if (virtqueue_get_vring_size(vrp->svq) < MAX_RPMSG_NUM_BUFS)
+		vrp->num_tx_buf = virtqueue_get_vring_size(vrp->svq);
 	else
-		vrp->num_bufs = MAX_RPMSG_NUM_BUFS;
+		vrp->num_tx_buf = MAX_RPMSG_NUM_BUFS;
 
-	vrp->buf_size = MAX_RPMSG_BUF_SIZE;
+	err = rpmsg_virtio_get_buf_size(vrp);
+	if (err)
+		goto vqs_del;
 
-	total_buf_space = vrp->num_bufs * vrp->buf_size;
+	total_buf_space = (vrp->num_rx_buf * vrp->rx_buf_size) +
+			  (vrp->num_tx_buf * vrp->tx_buf_size);
 
 	/* allocate coherent memory for the buffers */
 	bufs_va = dma_alloc_coherent(vdev->dev.parent,
@@ -871,18 +935,17 @@ static int rpmsg_probe(struct virtio_device *vdev)
 	dev_dbg(&vdev->dev, "buffers: va %p, dma %pad\n",
 		bufs_va, &vrp->bufs_dma);
 
-	/* half of the buffers is dedicated for RX */
-	vrp->rbufs = bufs_va;
+	/* first part of the buffers is dedicated for RX */
+	vrp->rx_bufs = bufs_va;
 
-	/* and half is dedicated for TX */
-	vrp->sbufs = bufs_va + total_buf_space / 2;
+	vrp->tx_bufs = bufs_va + (vrp->num_rx_buf * vrp->rx_buf_size);
 
 	/* set up the receive buffers */
-	for (i = 0; i < vrp->num_bufs / 2; i++) {
+	for (i = 0; i < vrp->num_rx_buf; i++) {
 		struct scatterlist sg;
-		void *cpu_addr = vrp->rbufs + i * vrp->buf_size;
+		void *cpu_addr = vrp->rx_bufs + i * vrp->rx_buf_size;
 
-		rpmsg_sg_init(&sg, cpu_addr, vrp->buf_size);
+		rpmsg_sg_init(&sg, cpu_addr, vrp->rx_buf_size);
 
 		err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, cpu_addr,
 					  GFP_KERNEL);
@@ -965,7 +1028,8 @@ static int rpmsg_remove_device(struct device *dev, void *data)
 static void rpmsg_remove(struct virtio_device *vdev)
 {
 	struct virtproc_info *vrp = vdev->priv;
-	size_t total_buf_space = vrp->num_bufs * vrp->buf_size;
+	size_t total_buf_space = (vrp->num_rx_buf * vrp->rx_buf_size) +
+				 (vrp->num_tx_buf * vrp->tx_buf_size);
 	int ret;
 
 	virtio_reset_device(vdev);
@@ -979,7 +1043,7 @@ static void rpmsg_remove(struct virtio_device *vdev)
 	vdev->config->del_vqs(vrp->vdev);
 
 	dma_free_coherent(vdev->dev.parent, total_buf_space,
-			  vrp->rbufs, vrp->bufs_dma);
+			  vrp->rx_bufs, vrp->bufs_dma);
 
 	kfree(vrp);
 }
@@ -991,6 +1055,7 @@ static struct virtio_device_id id_table[] = {
 
 static unsigned int features[] = {
 	VIRTIO_RPMSG_F_NS,
+	VIRTIO_RPMSG_F_BUFSZ,
 };
 
 static struct virtio_driver virtio_ipc_driver = {