Hello Xiang, On 5/9/19 3:00 PM, xiang xiao wrote: > On Thu, May 9, 2019 at 8:36 PM Arnaud Pouliquen <arnaud.pouliquen@xxxxxx> wrote: >> >> 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... >> > > Just saw this patchset, so it's common problem hit by many vendor, > rpmsg framework need to address it.:) > >> Main differences (except interesting RX/TX size split) seems that you >> - don't use the virtio_config_ops->get > > virtio_cread call virtio_config_ops->get internally, the ideal is same > for both patch, just the implementation detail is different. > >> - define a new feature VIRTIO_RPMSG_F_NS. > > I add this flag to keep the compatibility with old remote peer, and > also follow the common virito driver practice. I discussed with Loic, he is ok to go further with your patch and abandon his one. Please find some remarks below in-line > >> >> 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; In this case constant should be renamed DEFAULT_RPMSG_BUF_SIZE as it is no more a max value >>> + if (!vrp->sbuf_size) >>> + vrp->sbuf_size = MAX_RPMSG_BUF_SIZE; Here, if the config space exists you need to update it in consequence to ensure coherency with the remote processor config. >>> >>> /* 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 Strange to define a user space API for kernel usage need. Could you elaborate? >>> @@ -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 */ Would be useful to document it in rpmsg.txt >>> + >>> +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)); >>> + Wouldn't it be better to add an identifier and a version fields at the beginning of the structure? Idea would be to simplify a future extension In this case is VIRTIO_RPMSG_F_BUFSZ still useful? >>> +#endif /* _UAPI_LINUX_VIRTIO_RPMSG_H */ >>> -- Thanks Arnaud
