On Tue, May 19, 2026 at 11:36:47AM -0600, Mathieu Poirier wrote: > On Wed, Apr 29, 2026 at 09:10:52AM -0700, Tanmay Shah wrote: > > 512 bytes isn't always suitable for all case, let firmware > > maker decide the best value from resource table. > > enable by VIRTIO_RPMSG_F_BUFSZ feature bit. > > > > Signed-off-by: Tanmay Shah <[email protected]> > > --- > > > > Test done: > > - Verify this patch works with the existing firmware > > - Verify this patch works with the firmware that configures > > differt tx & rx buf size > > > > Changes in v2: > > - %s/sbuf_size/tx_buf_size/ > > - %s/rbuf_size/rx_buf_size/ > > - fix typo > > - do not use ALIGN on buf size, rely on allocator > > - make err msg more explicit, %s/vdev config:/bad vdev config/ > > - fix license and add AMD copyrights in the header virtio_rpmsg.h > > - Assign bit 1 to VIRTIO_RPMSG_F_BUFSZ feature > > - use __virtio32 over __u32 > > - add version field to virtio rpmsg config structure > > - move linux/virtio_rpmsg.h to linux/rpmsg/virtio_rpmsg.h > > > > drivers/rpmsg/virtio_rpmsg_bus.c | 70 ++++++++++++++++++++++-------- > > include/linux/rpmsg/virtio_rpmsg.h | 27 ++++++++++++ > > 2 files changed, 79 insertions(+), 18 deletions(-) > > create mode 100644 include/linux/rpmsg/virtio_rpmsg.h > > > > diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c > > b/drivers/rpmsg/virtio_rpmsg_bus.c > > index e59d8cf9b975..8116d94413cc 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> > > @@ -39,7 +40,8 @@ > > * @tx_bufs: kernel address of tx buffers > > * @num_rx_buf: total number of buffers for rx > > * @num_tx_buf: total number of buffers for tx > > - * @buf_size: size of one rx or tx buffer > > + * @rx_buf_size: size of one rx buffer > > + * @tx_buf_size: size of one tx buffer > > * @last_sbuf: index of last tx buffer used > > * @bufs_dma: dma base addr of the buffers > > * @tx_lock: protects svq and tx_bufs, to allow concurrent senders. > > @@ -59,7 +61,8 @@ struct virtproc_info { > > void *rx_bufs, *tx_bufs; > > unsigned int num_rx_buf; > > unsigned int num_tx_buf; > > - unsigned int buf_size; > > + unsigned int rx_buf_size; > > + unsigned int tx_buf_size; > > int last_sbuf; > > dma_addr_t bufs_dma; > > struct mutex tx_lock; > > @@ -68,9 +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 > > @@ -128,7 +128,7 @@ struct virtio_rpmsg_channel { > > * processor. > > */ > > #define MAX_RPMSG_NUM_BUFS (256) > > -#define MAX_RPMSG_BUF_SIZE (512) > > +#define DEFAULT_RPMSG_BUF_SIZE (512) > > > > /* > > * Local addresses are dynamically allocated on-demand. > > @@ -444,7 +444,7 @@ static void *get_a_tx_buf(struct virtproc_info *vrp) > > > > /* either pick the next unused tx buffer */ > > if (vrp->last_sbuf < vrp->num_tx_buf) > > - ret = vrp->tx_bufs + vrp->buf_size * vrp->last_sbuf++; > > + ret = vrp->tx_bufs + vrp->tx_buf_size * vrp->last_sbuf++; > > /* or recycle a used one */ > > else > > ret = virtqueue_get_buf(vrp->svq, &len); > > @@ -514,7 +514,7 @@ 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; > > } > > @@ -647,7 +647,7 @@ 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, > > @@ -673,7 +673,7 @@ 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; > > @@ -706,7 +706,7 @@ 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); > > @@ -824,6 +824,7 @@ static int rpmsg_probe(struct virtio_device *vdev) > > int err = 0, i; > > size_t total_buf_space; > > bool notify; > > + u16 version; > > > > vrp = kzalloc_obj(*vrp); > > if (!vrp) > > @@ -855,9 +856,41 @@ static int rpmsg_probe(struct virtio_device *vdev) > > else > > vrp->num_tx_buf = MAX_RPMSG_NUM_BUFS; > > > > - vrp->buf_size = MAX_RPMSG_BUF_SIZE; > > + /* > > + * 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)) { > > + /* note: virtio_rpmsg_config is defined from remote view */ > > + version = 0; > > + virtio_cread(vdev, struct virtio_rpmsg_config, > > + version, &version); > > + 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); > > + > > A check is also needed to make sure the version received from the resource > table > is '0'. > > > + /* 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 = %d, tx buf sz = > > %d\n", > > + vrp->rx_buf_size, vrp->tx_buf_size); > > + err = -EINVAL; > > + goto vqs_del; > > + } > > + > > + dev_dbg(&vdev->dev, > > + "vdev config: version=%d, rx buf sz = 0x%x, tx buf 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; > > + } > > > > - total_buf_space = (vrp->num_rx_buf + vrp->num_tx_buf) * 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, > > @@ -875,14 +908,14 @@ static int rpmsg_probe(struct virtio_device *vdev) > > vrp->rx_bufs = bufs_va; > > > > /* and second part is dedicated for TX */ > > - vrp->tx_bufs = bufs_va + vrp->num_rx_buf * vrp->buf_size; > > + vrp->tx_bufs = bufs_va + (vrp->num_rx_buf * vrp->rx_buf_size); > > > > /* set up the receive buffers */ > > for (i = 0; i < vrp->num_rx_buf; i++) { > > struct scatterlist sg; > > - void *cpu_addr = vrp->rx_bufs + 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); > > @@ -965,8 +998,8 @@ static int rpmsg_remove_device(struct device *dev, void > > *data) > > static void rpmsg_remove(struct virtio_device *vdev) > > { > > struct virtproc_info *vrp = vdev->priv; > > - unsigned int num_bufs = vrp->num_rx_buf + vrp->num_tx_buf; > > - size_t total_buf_space = 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); > > @@ -992,6 +1025,7 @@ 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 = { > > diff --git a/include/linux/rpmsg/virtio_rpmsg.h > > b/include/linux/rpmsg/virtio_rpmsg.h > > new file mode 100644 > > index 000000000000..285918be68b9 > > --- /dev/null > > +++ b/include/linux/rpmsg/virtio_rpmsg.h > > @@ -0,0 +1,27 @@ > > +/* SPDX-License-Identifier: GPL-2.0 */ > > +/* > > + * Copyright (C) Pinecone Inc. 2019 > > + * Copyright (C) Xiang Xiao <[email protected]> > > + * Copyright (C) Advanced Micro Devices, Inc. > > + */ > > + > > +#ifndef _LINUX_VIRTIO_RPMSG_H > > +#define _LINUX_VIRTIO_RPMSG_H > > + > > +#include <linux/types.h> > > +#include <linux/virtio_types.h> > > + > > +/* The feature bitmap for virtio rpmsg */ > > +#define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */ > > +#define VIRTIO_RPMSG_F_BUFSZ 1 /* RP get buffer size from config > > space */ > > + > > +struct virtio_rpmsg_config { > > + __virtio16 version; > > + /* The tx/rx individual buffer size(if VIRTIO_RPMSG_F_BUFSZ) */ > > + __virtio32 txbuf_size; > > + __virtio32 rxbuf_size; > > + __virtio32 reserved[14]; /* Reserve for the future use */ > > 66 byte for the configuratio space? I'm puzzled about the reserved[14], how > did > you come up with that number? > > The rest looks good to me.
... and I am done reviewing this set. > > > + /* Put the customize config here */ > > +} __packed; > > + > > +#endif /* _LINUX_VIRTIO_RPMSG_H */ > > -- > > 2.34.1 > >
