Re: [PATCH v4 2/4] rpmsg: move common structures and defines to headers

Mathieu Poirier
2020-08-11T18:00:32Z

On Wed, Jul 22, 2020 at 05:09:25PM +0200, Guennadi Liakhovetski wrote:
> virtio_rpmsg_bus.c keeps RPMsg protocol structure declarations and
> common defines like the ones, needed for name-space announcements,
> internal. Move them to common headers instead.
>
> Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
> ---
> drivers/rpmsg/virtio_rpmsg_bus.c | 78 +-----------------------------
> include/linux/virtio_rpmsg.h | 83 ++++++++++++++++++++++++++++++++

I am ambivalent about whether virtio_rpmsg.h should go under
include/linux/rpmsg/ or just stay where you have it. Not that it matters
much... I will let Bjorn make the final call on this.

If it does stay here, it will need to be added to MAINTAINERS.

For the v5.10 merge window only:

Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>

> include/uapi/linux/rpmsg.h | 3 ++
> 3 files changed, 88 insertions(+), 76 deletions(-)
> create mode 100644 include/linux/virtio_rpmsg.h
>
> diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c
> index 9006fc7f73d0..9d5dd3f0a648 100644
> --- a/drivers/rpmsg/virtio_rpmsg_bus.c
> +++ b/drivers/rpmsg/virtio_rpmsg_bus.c
> @@ -26,7 +26,9 @@
> #include <linux/virtio_byteorder.h>
> #include <linux/virtio_ids.h>
> #include <linux/virtio_config.h>
> +#include <linux/virtio_rpmsg.h>
> #include <linux/wait.h>
> +#include <uapi/linux/rpmsg.h>
>
> #include "rpmsg_internal.h"
>
> @@ -70,58 +72,6 @@ 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
> - * @dst: destination address
> - * @reserved: reserved for future use
> - * @len: length of payload (in bytes)
> - * @flags: message flags
> - * @data: @len bytes of message payload data
> - *
> - * Every message sent(/received) on the rpmsg bus begins with this header.
> - */
> -struct rpmsg_hdr {
> - __virtio32 src;
> - __virtio32 dst;
> - __virtio32 reserved;
> - __virtio16 len;
> - __virtio16 flags;
> - u8 data[];
> -} __packed;
> -
> -/**
> - * struct rpmsg_ns_msg - dynamic name service announcement message
> - * @name: name of remote service that is published
> - * @addr: address of remote service that is published
> - * @flags: indicates whether service is created or destroyed
> - *
> - * This message is sent across to publish a new service, or announce
> - * about its removal. When we receive these messages, an appropriate
> - * rpmsg channel (i.e device) is created/destroyed. In turn, the ->probe()
> - * or ->remove() handler of the appropriate rpmsg driver will be invoked
> - * (if/as-soon-as one is registered).
> - */
> -struct rpmsg_ns_msg {
> - char name[RPMSG_NAME_SIZE];
> - __virtio32 addr;
> - __virtio32 flags;
> -} __packed;
> -
> -/**
> - * enum rpmsg_ns_flags - dynamic name service announcement flags
> - *
> - * @RPMSG_NS_CREATE: a new remote service was just created
> - * @RPMSG_NS_DESTROY: a known remote service was just destroyed
> - */
> -enum rpmsg_ns_flags {
> - RPMSG_NS_CREATE = 0,
> - RPMSG_NS_DESTROY = 1,
> -};
> -
> /**
> * @vrp: the remote processor this channel belongs to
> */
> @@ -134,27 +84,6 @@ struct virtio_rpmsg_channel {
> #define to_virtio_rpmsg_channel(_rpdev) \
> container_of(_rpdev, struct virtio_rpmsg_channel, rpdev)
>
> -/*
> - * 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).
> - *
> - * Each buffer will have 16 bytes for the msg header and 496 bytes for
> - * the payload.
> - *
> - * This will utilize a maximum total space of 256KB for the buffers.
> - *
> - * We might also want to add support for user-provided buffers in time.
> - * This will allow bigger buffer size flexibility, and can also be used
> - * to achieve zero-copy messaging.
> - *
> - * Note that these numbers are purely a decision of this driver - we
> - * can change this without changing anything in the firmware of the remote
> - * processor.
> - */
> -#define MAX_RPMSG_NUM_BUFS (512)
> -#define MAX_RPMSG_BUF_SIZE (512)
> -
> /*
> * Local addresses are dynamically allocated on-demand.
> * We do not dynamically assign addresses from the low 1024 range,
> @@ -162,9 +91,6 @@ struct virtio_rpmsg_channel {
> */
> #define RPMSG_RESERVED_ADDRESSES (1024)
>
> -/* Address 53 is reserved for advertising remote services */
> -#define RPMSG_NS_ADDR (53)
> -
> static void virtio_rpmsg_destroy_ept(struct rpmsg_endpoint *ept);
> static int virtio_rpmsg_send(struct rpmsg_endpoint *ept, void *data, int len);
> static int virtio_rpmsg_sendto(struct rpmsg_endpoint *ept, void *data, int len,
> diff --git a/include/linux/virtio_rpmsg.h b/include/linux/virtio_rpmsg.h
> new file mode 100644
> index 000000000000..fcb523831e73
> --- /dev/null
> +++ b/include/linux/virtio_rpmsg.h
> @@ -0,0 +1,83 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +
> +#ifndef _LINUX_VIRTIO_RPMSG_H
> +#define _LINUX_VIRTIO_RPMSG_H
> +
> +#include <linux/mod_devicetable.h>
> +#include <linux/types.h>
> +#include <linux/virtio_types.h>
> +
> +/**
> + * struct rpmsg_hdr - common header for all rpmsg messages
> + * @src: source address
> + * @dst: destination address
> + * @reserved: reserved for future use
> + * @len: length of payload (in bytes)
> + * @flags: message flags
> + * @data: @len bytes of message payload data
> + *
> + * Every message sent(/received) on the rpmsg bus begins with this header.
> + */
> +struct rpmsg_hdr {
> + __virtio32 src;
> + __virtio32 dst;
> + __virtio32 reserved;
> + __virtio16 len;
> + __virtio16 flags;
> + u8 data[];
> +} __packed;
> +
> +/**
> + * struct rpmsg_ns_msg - dynamic name service announcement message
> + * @name: name of remote service that is published
> + * @addr: address of remote service that is published
> + * @flags: indicates whether service is created or destroyed
> + *
> + * This message is sent across to publish a new service, or announce
> + * about its removal. When we receive these messages, an appropriate
> + * rpmsg channel (i.e device) is created/destroyed. In turn, the ->probe()
> + * or ->remove() handler of the appropriate rpmsg driver will be invoked
> + * (if/as-soon-as one is registered).
> + */
> +struct rpmsg_ns_msg {
> + char name[RPMSG_NAME_SIZE];
> + __virtio32 addr;
> + __virtio32 flags;
> +} __packed;
> +
> +/**
> + * enum rpmsg_ns_flags - dynamic name service announcement flags
> + *
> + * @RPMSG_NS_CREATE: a new remote service was just created
> + * @RPMSG_NS_DESTROY: a known remote service was just destroyed
> + */
> +enum rpmsg_ns_flags {
> + RPMSG_NS_CREATE = 0,
> + RPMSG_NS_DESTROY = 1,
> +};
> +
> +/*
> + * 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).
> + *
> + * Each buffer will have 16 bytes for the msg header and 496 bytes for
> + * the payload.
> + *
> + * This will utilize a maximum total space of 256KB for the buffers.
> + *
> + * We might also want to add support for user-provided buffers in time.
> + * This will allow bigger buffer size flexibility, and can also be used
> + * to achieve zero-copy messaging.
> + *
> + * Note that these numbers are purely a decision of this driver - we
> + * can change this without changing anything in the firmware of the remote
> + * processor.
> + */
> +#define MAX_RPMSG_NUM_BUFS 512
> +#define MAX_RPMSG_BUF_SIZE 512
> +
> +/* Address 53 is reserved for advertising remote services */
> +#define RPMSG_NS_ADDR 53
> +
> +#endif
> diff --git a/include/uapi/linux/rpmsg.h b/include/uapi/linux/rpmsg.h
> index e14c6dab4223..d669c04ef289 100644
> --- a/include/uapi/linux/rpmsg.h
> +++ b/include/uapi/linux/rpmsg.h
> @@ -24,4 +24,7 @@ struct rpmsg_endpoint_info {
> #define RPMSG_CREATE_EPT_IOCTL _IOW(0xb5, 0x1, struct rpmsg_endpoint_info)
> #define RPMSG_DESTROY_EPT_IOCTL _IO(0xb5, 0x2)
>
> +/* The feature bitmap for virtio rpmsg */
> +#define VIRTIO_RPMSG_F_NS 0 /* RP supports name service notifications */
> +
> #endif
> --
> 2.27.0
>