From ca96ea25e51aeae45b0c947feb432fc74e2d1928 Mon Sep 17 00:00:00 2001 From: Tanmay Shah Date: Fri, 28 Aug 2026 07:58:50 -0700 Subject: rpmsg: virtio_rpmsg_bus: Get buffer size from config space 512 bytes isn't always suitable for all the cases, let firmware maker decide the best value from the resource table. Enabled by VIRTIO_RPMSG_F_BUFSZ feature bit. Signed-off-by: Tanmay Shah Acked-by: Arnaud Pouliquen Link: https://lore.kernel.org/r/20260828145853.2843486-4-tanmay.shah@amd.com Signed-off-by: Mathieu Poirier --- include/linux/rpmsg/virtio_rpmsg.h | 41 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) create mode 100644 include/linux/rpmsg/virtio_rpmsg.h (limited to 'include/linux') diff --git a/include/linux/rpmsg/virtio_rpmsg.h b/include/linux/rpmsg/virtio_rpmsg.h new file mode 100644 index 000000000000..0872cbca4593 --- /dev/null +++ b/include/linux/rpmsg/virtio_rpmsg.h @@ -0,0 +1,41 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) Pinecone Inc. 2019 + * Copyright (C) Xiang Xiao + * Copyright (C) Advanced Micro Devices, Inc. 2026 + */ + +#ifndef _LINUX_VIRTIO_RPMSG_H +#define _LINUX_VIRTIO_RPMSG_H + +#include +#include + +/* The feature bitmap for virtio rpmsg */ +#define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */ +#define VIRTIO_RPMSG_F_BUFSZ 1 /* RP advertises RX/TX buffer sizes from config space */ + +/* Version of struct virtio_rpmsg_config understood by this driver */ +#define RPMSG_VDEV_CONFIG_V1 1 + +/** + * struct virtio_rpmsg_config - config space for rpmsg virtio device + * + * @version: version of this structure, currently %RPMSG_VDEV_CONFIG_V1. + * @size: size of this structure in bytes. + * @txbuf_size: Tx buf size from remote's view. For Linux this is rx buf size. + * @rxbuf_size: Rx buf size from remote's view. For Linux this is tx buf size. + * + * This is the configuration structure shared by the device and the driver, + * read when %VIRTIO_RPMSG_F_BUFSZ is negotiated. The fields are laid out so + * the structure is naturally 32-bit aligned. + */ +struct virtio_rpmsg_config { + u8 version; + __virtio16 size; + /* The tx/rx individual buffer size (if VIRTIO_RPMSG_F_BUFSZ) */ + __virtio32 txbuf_size; + __virtio32 rxbuf_size; +} __packed; + +#endif /* _LINUX_VIRTIO_RPMSG_H */ -- cgit v1.2.3