Hi Tanmay, On Fri, Nov 14, 2025 at 10:46:39AM -0800, Tanmay Shah wrote: > From: Xiang Xiao <[email protected]> >
This feature has been abandoned a long time ago - you own it now. > it's useful if the communication throughput is different from each side > Please provide a better changelog. > Signed-off-by: Xiang Xiao <[email protected]> > Signed-off-by: Tanmay Shah <[email protected]> > --- > drivers/rpmsg/virtio_rpmsg_bus.c | 47 ++++++++++++++++---------------- > 1 file changed, 24 insertions(+), 23 deletions(-) > > diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c > b/drivers/rpmsg/virtio_rpmsg_bus.c > index 484890b4a6a7..cc26dfcc3e29 100644 > --- a/drivers/rpmsg/virtio_rpmsg_bus.c > +++ b/drivers/rpmsg/virtio_rpmsg_bus.c > @@ -37,8 +37,9 @@ > * @svq: tx virtqueue > * @rbufs: kernel address of rx buffers > * @sbufs: kernel address of tx buffers > - * @num_bufs: total number of buffers for rx and tx > - * @buf_size: size of one rx or tx buffer > + * @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 > * @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. > @@ -57,7 +58,8 @@ struct virtproc_info { > struct virtio_device *vdev; > struct virtqueue *rvq, *svq; > void *rbufs, *sbufs; > - unsigned int num_bufs; > + unsigned int num_rbufs; > + unsigned int num_sbufs; > unsigned int buf_size; > int last_sbuf; > dma_addr_t bufs_dma; > @@ -112,7 +114,7 @@ struct virtio_rpmsg_channel { > /* > * We're allocating buffers of 512 bytes each for communications. The > * number of buffers will be computed from the number of buffers supported > - * by the vring, upto a maximum of 512 buffers (256 in each direction). > + * by the vring, up to a maximum of 256 in each direction. > * > * Each buffer will have 16 bytes for the msg header and 496 bytes for > * the payload. > @@ -127,7 +129,7 @@ struct virtio_rpmsg_channel { > * can change this without changing anything in the firmware of the remote > * processor. > */ > -#define MAX_RPMSG_NUM_BUFS (512) > +#define MAX_RPMSG_NUM_BUFS (256) > #define MAX_RPMSG_BUF_SIZE (512) > > /* > @@ -439,11 +441,8 @@ static void *get_a_tx_buf(struct virtproc_info *vrp) > /* support multiple concurrent senders */ > mutex_lock(&vrp->tx_lock); > > - /* > - * either pick the next unused tx buffer > - * (half of our buffers are used for sending messages) > - */ > - if (vrp->last_sbuf < vrp->num_bufs / 2) > + /* either pick the next unused tx buffer */ > + if (vrp->last_sbuf < vrp->num_sbufs) > ret = vrp->sbufs + vrp->buf_size * vrp->last_sbuf++; > /* or recycle a used one */ > else > @@ -878,19 +877,20 @@ static int rpmsg_probe(struct virtio_device *vdev) > vrp->rvq = vqs[0]; > vrp->svq = vqs[1]; > > - /* we expect symmetric tx/rx vrings */ > - WARN_ON(virtqueue_get_vring_size(vrp->rvq) != > - virtqueue_get_vring_size(vrp->svq)); > - > /* we need less buffers if vrings are small */ > - if (virtqueue_get_vring_size(vrp->rvq) < MAX_RPMSG_NUM_BUFS / 2) > - vrp->num_bufs = virtqueue_get_vring_size(vrp->rvq) * 2; > + if (virtqueue_get_vring_size(vrp->rvq) < MAX_RPMSG_NUM_BUFS) > + vrp->num_rbufs = virtqueue_get_vring_size(vrp->rvq); > + else > + vrp->num_rbufs = MAX_RPMSG_NUM_BUFS; > + > + if (virtqueue_get_vring_size(vrp->svq) < MAX_RPMSG_NUM_BUFS) > + vrp->num_sbufs = virtqueue_get_vring_size(vrp->svq); > else > - vrp->num_bufs = MAX_RPMSG_NUM_BUFS; > + vrp->num_sbufs = MAX_RPMSG_NUM_BUFS; > > vrp->buf_size = MAX_RPMSG_BUF_SIZE; > > - total_buf_space = vrp->num_bufs * vrp->buf_size; > + total_buf_space = (vrp->num_rbufs + vrp->num_sbufs) * vrp->buf_size; > > /* allocate coherent memory for the buffers */ > bufs_va = dma_alloc_coherent(vdev->dev.parent, > @@ -904,14 +904,14 @@ static int rpmsg_probe(struct virtio_device *vdev) > dev_dbg(&vdev->dev, "buffers: va %p, dma %pad\n", > bufs_va, &vrp->bufs_dma); > > - /* half of the buffers is dedicated for RX */ > + /* first part of the buffers is dedicated for RX */ > vrp->rbufs = bufs_va; > > - /* and half is dedicated for TX */ > - vrp->sbufs = bufs_va + total_buf_space / 2; > + /* and second part is dedicated for TX */ > + vrp->sbufs = bufs_va + vrp->num_rbufs * vrp->buf_size; > > /* set up the receive buffers */ > - for (i = 0; i < vrp->num_bufs / 2; i++) { > + for (i = 0; i < vrp->num_rbufs; i++) { > struct scatterlist sg; > void *cpu_addr = vrp->rbufs + i * vrp->buf_size; > > @@ -1001,7 +1001,8 @@ static int rpmsg_remove_device(struct device *dev, void > *data) > static void rpmsg_remove(struct virtio_device *vdev) > { > struct virtproc_info *vrp = vdev->priv; > - size_t total_buf_space = vrp->num_bufs * vrp->buf_size; > + unsigned int num_bufs = vrp->num_rbufs + vrp->num_sbufs; > + size_t total_buf_space = num_bufs * vrp->buf_size; > int ret; > > virtio_reset_device(vdev); > -- > 2.34.1 >
