Commit e279317e authored by Arnaud Pouliquen's avatar Arnaud Pouliquen Committed by Greg Kroah-Hartman
Browse files

rpmsg: core: add API to get MTU 



Return the rpmsg buffer MTU for sending message, so rpmsg users
can split a long message in several sub rpmsg buffers.

Reviewed-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Reviewed-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
Acked-by: default avatarSuman Anna <s-anna@ti.com>
Signed-off-by: default avatarArnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Link: https://lore.kernel.org/r/20211015094701.5732-2-arnaud.pouliquen@foss.st.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 74365bc1

drivers/rpmsg/rpmsg_core.c

+21 −0
Original line number Diff line number Diff line
@@ -327,6 +327,27 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, 
}

EXPORT_SYMBOL(rpmsg_trysend_offchannel);



/**

 * rpmsg_get_mtu() - get maximum transmission buffer size for sending message.

 * @ept: the rpmsg endpoint

 *

 * This function returns maximum buffer size available for a single outgoing message.

 *

 * Return: the maximum transmission size on success and an appropriate error

 * value on failure.

 */



ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept)

{

	if (WARN_ON(!ept))

		return -EINVAL;

	if (!ept->ops->get_mtu)

		return -ENOTSUPP;



	return ept->ops->get_mtu(ept);

}

EXPORT_SYMBOL(rpmsg_get_mtu);



/*

 * match a rpmsg channel with a channel info struct.

 * this is used to make sure we're not creating rpmsg devices for channels

drivers/rpmsg/rpmsg_internal.h

+2 −0
Original line number Diff line number Diff line
@@ -53,6 +53,7 @@ struct rpmsg_device_ops { 
 * @trysendto:		see @rpmsg_trysendto(), optional

 * @trysend_offchannel:	see @rpmsg_trysend_offchannel(), optional

 * @poll:		see @rpmsg_poll(), optional

 * @get_mtu:		see @rpmsg_get_mtu(), optional

 *

 * Indirection table for the operations that a rpmsg backend should implement.

 * In addition to @destroy_ept, the backend must at least implement @send and
@@ -72,6 +73,7 @@ struct rpmsg_endpoint_ops { 
			     void *data, int len);

	__poll_t (*poll)(struct rpmsg_endpoint *ept, struct file *filp,

			     poll_table *wait);

	ssize_t (*get_mtu)(struct rpmsg_endpoint *ept);

};



struct device *rpmsg_find_device(struct device *parent,

drivers/rpmsg/virtio_rpmsg_bus.c

+10 −0
Original line number Diff line number Diff line
@@ -149,6 +149,7 @@ static int virtio_rpmsg_trysendto(struct rpmsg_endpoint *ept, void *data, 
				  int len, u32 dst);

static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src,

					   u32 dst, void *data, int len);

static ssize_t virtio_rpmsg_get_mtu(struct rpmsg_endpoint *ept);

static struct rpmsg_device *__rpmsg_create_channel(struct virtproc_info *vrp,

						   struct rpmsg_channel_info *chinfo);
@@ -160,6 +161,7 @@ static const struct rpmsg_endpoint_ops virtio_endpoint_ops = { 
	.trysend = virtio_rpmsg_trysend,

	.trysendto = virtio_rpmsg_trysendto,

	.trysend_offchannel = virtio_rpmsg_trysend_offchannel,

	.get_mtu = virtio_rpmsg_get_mtu,

};



/**
@@ -696,6 +698,14 @@ static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, 
	return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false);

}



static ssize_t virtio_rpmsg_get_mtu(struct rpmsg_endpoint *ept)

{

	struct rpmsg_device *rpdev = ept->rpdev;

	struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev);



	return vch->vrp->buf_size - sizeof(struct rpmsg_hdr);

}



static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev,

			     struct rpmsg_hdr *msg, unsigned int len)

{

include/linux/rpmsg.h

+10 −0
Original line number Diff line number Diff line
@@ -186,6 +186,8 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, 
__poll_t rpmsg_poll(struct rpmsg_endpoint *ept, struct file *filp,

			poll_table *wait);



ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept);



#else



static inline int rpmsg_register_device(struct rpmsg_device *rpdev)
@@ -296,6 +298,14 @@ static inline __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, 
	return 0;

}



static inline ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept)

{

	/* This shouldn't be possible */

	WARN_ON(1);



	return -ENXIO;

}



#endif /* IS_ENABLED(CONFIG_RPMSG) */



/* use a macro to avoid include chaining to get THIS_MODULE */