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X-OriginatorOrg: foss.st.com X-MS-Exchange-CrossTenant-OriginalArrivalTime: 21 Nov 2025 09:44:13.2305 (UTC) X-MS-Exchange-CrossTenant-Network-Message-Id: 08e43389-18bb-4b5c-8128-08de28e2876f X-MS-Exchange-CrossTenant-Id: 75e027c9-20d5-47d5-b82f-77d7cd041e8f X-MS-Exchange-CrossTenant-OriginalAttributedTenantConnectingIp: TenantId=75e027c9-20d5-47d5-b82f-77d7cd041e8f;Ip=[164.130.1.60];Helo=[smtpO365.st.com] X-MS-Exchange-CrossTenant-AuthSource: AM2PEPF0001C710.eurprd05.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Anonymous X-MS-Exchange-CrossTenant-FromEntityHeader: HybridOnPrem X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR10MB3296 X-Authority-Analysis: v=2.4 cv=DNSCIiNb c=1 sm=1 tr=0 ts=69203472 cx=c_pps a=lTC8IeES+PzMwLEJ9HO3BQ==:117 a=uCuRqK4WZKO1kjFMGfU4lQ==:17 a=6eWqkTHjU83fiwn7nKZWdM+Sl24=:19 a=FOPVHIcnkjUA:10 a=IkcTkHD0fZMA:10 a=6UeiqGixMTsA:10 a=s63m1ICgrNkA:10 a=KrXZwBdWH7kA:10 a=VkNPw1HP01LnGYTKEx00:22 a=pGLkceISAAAA:8 a=IeNN-m2dAAAA:8 a=zd2uoN0lAAAA:8 a=j2MSVUfDAAAA:8 a=oGp5VSZPowymOWLuIFMA:9 a=QEXdDO2ut3YA:10 a=9a3gGlFUS2ax-cngMeOV:22 X-Proofpoint-GUID: 3pJ72A7S460aWc_9x3g-MkcWGNwucJy- X-Proofpoint-ORIG-GUID: 3pJ72A7S460aWc_9x3g-MkcWGNwucJy- X-Proofpoint-Spam-Details-Enc: AW1haW4tMjUxMTIxMDA3MyBTYWx0ZWRfXyzMkpG9BEO7V PpBIGunX1PeeNMCkN3MaAZi1ZundzZ7kthN9SGCHRYHPRDqIRcb1lKhNpjL/1N3ThOiGoppONpP SZ6kso0nOVGYhjQh7YT0GNE8AgcrAVgT6mJR+KMwJQp5mTVrOhS07D8bwMxrl6ezQW0YIUV2vXK 4Z92yrkS6S/KLvcYYyk2fMGrGKORezAVbLhTcSV4mHPExNslXYi3WFjX0Yss6m9wc07Td/BiCT7 wt2edZhJkfzPYrgjsFhdOdZvw40LxrElwRLHq1HYRXV4A6ZVNIM6cRjndwU+hfbqoba7GVHqUzh ONtwlYlvjohqFCWyYAPK4AyApxizpYSLhYsv/dGh2pjNwMzNRVAnzmPLekGiHirTHspxb4tCy2j Ss6DDkuJj55w3ebK4cMwPLKp10597Q== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1121,Hydra:6.1.9,FMLib:17.12.100.49 definitions=2025-11-21_03,2025-11-20_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 bulkscore=0 suspectscore=0 impostorscore=0 malwarescore=0 adultscore=0 lowpriorityscore=0 phishscore=0 clxscore=1015 spamscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2510240001 definitions=main-2511210073 On 11/14/25 19:46, Tanmay Shah wrote: > From: Xiang Xiao > > 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: Xiang Xiao > Signed-off-by: Tanmay Shah > --- > drivers/rpmsg/virtio_rpmsg_bus.c | 68 +++++++++++++++++++++++--------- > include/linux/virtio_rpmsg.h | 24 +++++++++++ > 2 files changed, 74 insertions(+), 18 deletions(-) > create mode 100644 include/linux/virtio_rpmsg.h > > diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c > index cc26dfcc3e29..03dd5535880a 100644 > --- a/drivers/rpmsg/virtio_rpmsg_bus.c > +++ b/drivers/rpmsg/virtio_rpmsg_bus.c > @@ -25,6 +25,7 @@ > #include > #include > #include > +#include > #include > #include > > @@ -39,7 +40,8 @@ > * @sbufs: kernel address of tx buffers > * @num_rbufs: total number of buffers for rx > * @num_sbufs: total number of buffers for tx > - * @buf_size: size of one rx or tx buffer > + * @rbuf_size: size of one rx buffer > + * @sbuf_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, sbufs and sleepers, to allow concurrent senders. > @@ -60,7 +62,8 @@ struct virtproc_info { > void *rbufs, *sbufs; > unsigned int num_rbufs; > unsigned int num_sbufs; > - unsigned int buf_size; > + unsigned int rbuf_size; > + unsigned int sbuf_size; > int last_sbuf; > dma_addr_t bufs_dma; > struct mutex tx_lock; > @@ -70,9 +73,6 @@ struct virtproc_info { > atomic_t sleepers; > }; > > -/* 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 > @@ -130,7 +130,7 @@ 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. > @@ -443,7 +443,7 @@ static void *get_a_tx_buf(struct virtproc_info *vrp) > > /* either pick the next unused tx buffer */ > if (vrp->last_sbuf < vrp->num_sbufs) > - ret = vrp->sbufs + vrp->buf_size * vrp->last_sbuf++; > + ret = vrp->sbufs + vrp->sbuf_size * vrp->last_sbuf++; > /* or recycle a used one */ > else > ret = virtqueue_get_buf(vrp->svq, &len); > @@ -569,7 +569,7 @@ 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->sbuf_size - sizeof(struct rpmsg_hdr)) { > dev_err(dev, "message is too big (%d)\n", len); > return -EMSGSIZE; > } > @@ -680,7 +680,7 @@ 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->sbuf_size - sizeof(struct rpmsg_hdr); > } > > static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev, > @@ -706,7 +706,7 @@ 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->rbuf_size || > msg_len > (len - sizeof(struct rpmsg_hdr))) { > dev_warn(dev, "inbound msg too big: (%d, %d)\n", len, msg_len); > return -EINVAL; > @@ -739,7 +739,7 @@ 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->rbuf_size); > > /* add the buffer back to the remote processor's virtqueue */ > err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, msg, GFP_KERNEL); > @@ -888,9 +888,39 @@ static int rpmsg_probe(struct virtio_device *vdev) > else > vrp->num_sbufs = 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 */ > + virtio_cread(vdev, struct virtio_rpmsg_config, > + txbuf_size, &vrp->rbuf_size); > + virtio_cread(vdev, struct virtio_rpmsg_config, > + rxbuf_size, &vrp->sbuf_size); > + > + /* The buffers must hold rpmsg header atleast */ typo: /* The buffers must hold at least the rpmsg header */ > + if (vrp->rbuf_size < sizeof(struct rpmsg_hdr) || > + vrp->sbuf_size < sizeof(struct rpmsg_hdr)) { > + dev_err(&vdev->dev, > + "vdev config: rx buf sz = %d, tx buf sz = %d\n", message could be more explicit: s/"vdev config:/"bad vdev config:/ > + vrp->rbuf_size, vrp->sbuf_size); > + err = -EINVAL; > + goto vqs_del; > + } > + > + dev_dbg(&vdev->dev, > + "vdev config: rx buf sz = 0x%x, tx buf sz = 0x%x\n", > + vrp->rbuf_size, vrp->sbuf_size); > + } else { > + vrp->rbuf_size = DEFAULT_RPMSG_BUF_SIZE; > + vrp->sbuf_size = DEFAULT_RPMSG_BUF_SIZE; > + } > > - total_buf_space = (vrp->num_rbufs + vrp->num_sbufs) * vrp->buf_size; > + total_buf_space = (vrp->num_rbufs * vrp->rbuf_size) + > + (vrp->num_sbufs * vrp->sbuf_size); > + total_buf_space = ALIGN(total_buf_space, PAGE_SIZE); Needed? The allocator does not manage the page alignment? > > /* allocate coherent memory for the buffers */ > bufs_va = dma_alloc_coherent(vdev->dev.parent, > @@ -908,14 +938,14 @@ static int rpmsg_probe(struct virtio_device *vdev) > vrp->rbufs = bufs_va; > > /* and second part is dedicated for TX */ > - vrp->sbufs = bufs_va + vrp->num_rbufs * vrp->buf_size; > + vrp->sbufs = bufs_va + (vrp->num_rbufs * vrp->rbuf_size); > > /* set up the receive buffers */ > for (i = 0; i < vrp->num_rbufs; i++) { > struct scatterlist sg; > - void *cpu_addr = vrp->rbufs + i * vrp->buf_size; > + void *cpu_addr = vrp->rbufs + i * vrp->rbuf_size; > > - rpmsg_sg_init(&sg, cpu_addr, vrp->buf_size); > + rpmsg_sg_init(&sg, cpu_addr, vrp->rbuf_size); > > err = virtqueue_add_inbuf(vrp->rvq, &sg, 1, cpu_addr, > GFP_KERNEL); > @@ -1001,8 +1031,8 @@ 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_rbufs + vrp->num_sbufs; > - size_t total_buf_space = num_bufs * vrp->buf_size; > + size_t total_buf_space = (vrp->num_rbufs * vrp->rbuf_size) + > + (vrp->num_sbufs * vrp->sbuf_size); > int ret; > > virtio_reset_device(vdev); > @@ -1015,6 +1045,7 @@ static void rpmsg_remove(struct virtio_device *vdev) > > vdev->config->del_vqs(vrp->vdev); > > + total_buf_space = ALIGN(total_buf_space, PAGE_SIZE); > dma_free_coherent(vdev->dev.parent, total_buf_space, > vrp->rbufs, vrp->bufs_dma); > > @@ -1028,6 +1059,7 @@ 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/virtio_rpmsg.h b/include/linux/virtio_rpmsg.h > new file mode 100644 > index 000000000000..6406bc505383 > --- /dev/null > +++ b/include/linux/virtio_rpmsg.h > @@ -0,0 +1,24 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ This licensing seems reserved for the UAPIs > +/* > + * Copyright (C) Pinecone Inc. 2019 > + * Copyright (C) Xiang Xiao > + */ > + > +#ifndef _LINUX_VIRTIO_RPMSG_H > +#define _LINUX_VIRTIO_RPMSG_H > + > +#include > + > +/* The feature bitmap for virtio rpmsg */ > +#define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */ > +#define VIRTIO_RPMSG_F_BUFSZ 2 /* RP get buffer size from config space */ > + > +struct virtio_rpmsg_config { > + /* The tx/rx individual buffer size(if VIRTIO_RPMSG_F_BUFSZ) */ > + __u32 txbuf_size; > + __u32 rxbuf_size; > + __u32 reserved[14]; /* Reserve for the future use */ > + /* Put the customize config here */ > +} __attribute__((packed)); I am still convinced that adding a version field would help with future improvements, even though a feature bit field can be used to handle new configurations. Indeed, how can we address the need for more space beyond the 14 reserved words? Thanks, Arnaud > + > +#endif /* _LINUX_VIRTIO_RPMSG_H */