On Wed, Jun 5, 2019 at 4:02 PM Arnaud Pouliquen <arnaud.pouliquen@xxxxxx> wrote: > > > > On 6/5/19 4:40 AM, xiang xiao wrote: > > On Tue, Jun 4, 2019 at 10:25 PM Arnaud Pouliquen > > <arnaud.pouliquen@xxxxxx> wrote: > >> > >> 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 > > > > Yes, DEFAULT_RPMSG_BUF_SIZE is more reasonable now. > > > >>>>> + 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. > > > > The update is already done in if (virtio_has_feature(vdev, > > VIRTIO_RPMSG_F_BUFSZ)), here just handle the zero value in config > > space which mean the remote side want to use the default value even > > VIRTIO_RPMSG_F_BUFSZ set. > > For example: > > 1.remote side want to change one direction buffer size, but keep > > another direction as default > > 2.or remote side want to change other config options(define in the > > furture) not the buffer size > > In code above i can see a virtio_cread of the config structure, but no > writing of it... > I mentioned the configs space in the resource table itself. > Without an update, you must ensure that both have the same default > value... In addition, it makes sense that the master can update the > buffer size according to some other constraints. Get your point, thanks. > > > > >> > >>>>> > >>>>> /* 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? > > > > I just follow the practice other virtio drivers(e.g. > > include/uapi/virtio_net.h) applied, but rpmsg driver don't need to > > talk with the host VM software like other virtio driver, yes this > > header file isn't really needed. > > > >>>>> @@ -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 > > > > Good point, but it is better to put them into this document: > > https://docs.oasis-open.org/virtio/virtio/v1.1/csprd01/virtio-v1.1-csprd01.html > > like other vritio driver spec. > > > >>>>> + > >>>>> +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? > >> > > > > Yes, I consider this option before, but after review all > > include/uapi/virtio_*.h, I found that virito driver prefer feature > > bits than version number to handle the compability issue. > > For example, if we need introduce more options in the furture, we need: > > 1.Add new feature bit to notice the option exist > > 2.Allocate the field from reserved space > > > >>>>> +#endif /* _UAPI_LINUX_VIRTIO_RPMSG_H */ > >>>>> > >> -- > >> Thanks > >> Arnaud
