Hello Xiang, Similar mechanism has been proposed by Loic 2 years ago (link to the series here https://lkml.org/lkml/2017/3/28/349). Did you see them? Regarding history, patches seem just on hold... Main differences (except interesting RX/TX size split) seems that you - don't use the virtio_config_ops->get - define a new feature VIRTIO_RPMSG_F_NS. Regards Arnaud On 1/31/19 4:41 PM, Xiang Xiao 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: Xiang Xiao <xiaoxiang@xxxxxxxxxx> > --- > drivers/rpmsg/virtio_rpmsg_bus.c | 50 +++++++++++++++++++++++++-------------- > include/uapi/linux/virtio_rpmsg.h | 24 +++++++++++++++++++ > 2 files changed, 56 insertions(+), 18 deletions(-) > create mode 100644 include/uapi/linux/virtio_rpmsg.h > > diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c > index 59c4554..049dd97 100644 > --- a/drivers/rpmsg/virtio_rpmsg_bus.c > +++ b/drivers/rpmsg/virtio_rpmsg_bus.c > @@ -16,6 +16,7 @@ > #include <linux/virtio.h> > #include <linux/virtio_ids.h> > #include <linux/virtio_config.h> > +#include <linux/virtio_rpmsg.h> > #include <linux/scatterlist.h> > #include <linux/dma-mapping.h> > #include <linux/slab.h> > @@ -38,7 +39,8 @@ > * @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 > * @rbufs_dma: dma base addr of rx buffers > * @sbufs_dma: dma base addr of tx buffers > @@ -61,7 +63,8 @@ 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 rbufs_dma; > dma_addr_t sbufs_dma; > @@ -73,9 +76,6 @@ struct virtproc_info { > struct rpmsg_endpoint *ns_ept; > }; > > -/* 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 > @@ -452,7 +452,7 @@ 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); > @@ -578,7 +578,7 @@ 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; > } > @@ -718,7 +718,7 @@ 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; > @@ -751,7 +751,7 @@ static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev, > dev_warn(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); > @@ -907,11 +907,24 @@ static int rpmsg_probe(struct virtio_device *vdev) > else > vrp->num_sbufs = MAX_RPMSG_NUM_BUFS; > > - vrp->buf_size = MAX_RPMSG_BUF_SIZE; > + /* try to get buffer size from config space */ > + 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); > + } > + > + /* use the default if resource table doesn't provide one */ > + if (!vrp->rbuf_size) > + vrp->rbuf_size = MAX_RPMSG_BUF_SIZE; > + if (!vrp->sbuf_size) > + vrp->sbuf_size = MAX_RPMSG_BUF_SIZE; > > /* allocate coherent memory for the buffers */ > vrp->rbufs = dma_alloc_coherent(vdev->dev.parent->parent, > - vrp->num_rbufs * vrp->buf_size, > + vrp->num_rbufs * vrp->rbuf_size, > &vrp->rbufs_dma, GFP_KERNEL); > if (!vrp->rbufs) { > err = -ENOMEM; > @@ -922,7 +935,7 @@ static int rpmsg_probe(struct virtio_device *vdev) > vrp->rbufs, &vrp->rbufs_dma); > > vrp->sbufs = dma_alloc_coherent(vdev->dev.parent->parent, > - vrp->num_sbufs * vrp->buf_size, > + vrp->num_sbufs * vrp->sbuf_size, > &vrp->sbufs_dma, GFP_KERNEL); > if (!vrp->sbufs) { > err = -ENOMEM; > @@ -935,9 +948,9 @@ static int rpmsg_probe(struct virtio_device *vdev) > /* 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); > @@ -984,11 +997,11 @@ static int rpmsg_probe(struct virtio_device *vdev) > > free_sbufs: > dma_free_coherent(vdev->dev.parent->parent, > - vrp->num_sbufs * vrp->buf_size, > + vrp->num_sbufs * vrp->sbuf_size, > vrp->sbufs, vrp->sbufs_dma); > free_rbufs: > dma_free_coherent(vdev->dev.parent->parent, > - vrp->num_rbufs * vrp->buf_size, > + vrp->num_rbufs * vrp->rbuf_size, > vrp->rbufs, vrp->rbufs_dma); > vqs_del: > vdev->config->del_vqs(vrp->vdev); > @@ -1023,10 +1036,10 @@ static void rpmsg_remove(struct virtio_device *vdev) > vdev->config->del_vqs(vrp->vdev); > > dma_free_coherent(vdev->dev.parent->parent, > - vrp->num_sbufs * vrp->buf_size, > + vrp->num_sbufs * vrp->sbuf_size, > vrp->sbufs, vrp->sbufs_dma); > dma_free_coherent(vdev->dev.parent->parent, > - vrp->num_rbufs * vrp->buf_size, > + vrp->num_rbufs * vrp->rbuf_size, > vrp->rbufs, vrp->rbufs_dma); > > kfree(vrp); > @@ -1039,6 +1052,7 @@ 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/uapi/linux/virtio_rpmsg.h b/include/uapi/linux/virtio_rpmsg.h > new file mode 100644 > index 0000000..24fa0dd > --- /dev/null > +++ b/include/uapi/linux/virtio_rpmsg.h > @@ -0,0 +1,24 @@ > +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ > +/* > + * Copyright (C) Pinecone Inc. 2019 > + * Copyright (C) Xiang Xiao <xiaoxiang@xxxxxxxxxxxx> > + */ > + > +#ifndef _UAPI_LINUX_VIRTIO_RPMSG_H > +#define _UAPI_LINUX_VIRTIO_RPMSG_H > + > +#include <linux/types.h> > + > +/* 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)); > + > +#endif /* _UAPI_LINUX_VIRTIO_RPMSG_H */ >
