On 7/1/19 7:31 AM, Bjorn Andersson wrote: > On Fri 10 May 08:02 PDT 2019, Arnaud Pouliquen wrote: > >> Return the rpmsg buffer payload size for sending message, so rpmsg users >> can split a long message in several sub rpmsg buffers. >> >> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx> >> Signed-off-by: Fabien Dessenne <fabien.dessenne@xxxxxx> > > This should list each person who dealt with the patch. So the first > would be the author and the last would be the one that posted it on the > list. > > If you both authored the patch then you should add Co-developed-by to > denote this. ok i will update it > >> --- >> drivers/rpmsg/rpmsg_core.c | 20 ++++++++++++++++++++ >> drivers/rpmsg/rpmsg_internal.h | 2 ++ >> drivers/rpmsg/virtio_rpmsg_bus.c | 11 +++++++++++ >> include/linux/rpmsg.h | 10 ++++++++++ >> 4 files changed, 43 insertions(+) >> >> diff --git a/drivers/rpmsg/rpmsg_core.c b/drivers/rpmsg/rpmsg_core.c >> index 8122807db380..75c8c403ffe5 100644 >> --- a/drivers/rpmsg/rpmsg_core.c >> +++ b/drivers/rpmsg/rpmsg_core.c >> @@ -283,6 +283,26 @@ int rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, u32 dst, >> } >> EXPORT_SYMBOL(rpmsg_trysend_offchannel); >> >> +/** >> + * rpmsg_get_buf_payload_size() >> + * This function returns buffer payload size available for sending messages. >> + * >> + * @ept: the rpmsg endpoint >> + * >> + * Returns buffer payload size on success and an appropriate error value on >> + * failure. >> + */ > > Please read > https://www.kernel.org/doc/Documentation/kernel-doc-nano-HOWTO.txt oops sorry for this dirty documentation. > >> +int rpmsg_get_buf_payload_size(struct rpmsg_endpoint *ept) > > payload size can have many meanings and hopefully we'll end up in a > situation where its dynamic. But it could be considered useful to have a > way to query the maximum transmission size in such a setup. > > So please rename this rpmsg_get_mtu() or something similar. > > And I would prefer ssize_t as return type. ssize_t rpmsg_get_mtu(struct rpmsg_endpoint *ept) sounds good, ok for this >> +{ >> + if (WARN_ON(!ept)) >> + return -EINVAL; >> + if (!ept->ops->get_buf_payload_size) >> + return -ENXIO; >> + >> + return ept->ops->get_buf_payload_size(ept); >> +} >> +EXPORT_SYMBOL(rpmsg_get_buf_payload_size); >> + >> /* >> * match an rpmsg channel with a channel info struct. >> * this is used to make sure we're not creating rpmsg devices for channels >> diff --git a/drivers/rpmsg/rpmsg_internal.h b/drivers/rpmsg/rpmsg_internal.h >> index 0d791c30b7ea..6f733a556139 100644 >> --- a/drivers/rpmsg/rpmsg_internal.h >> +++ b/drivers/rpmsg/rpmsg_internal.h >> @@ -46,6 +46,7 @@ struct rpmsg_device_ops { >> * @trysend: see @rpmsg_trysend(), required >> * @trysendto: see @rpmsg_trysendto(), optional >> * @trysend_offchannel: see @rpmsg_trysend_offchannel(), optional >> + * @get_buf_payload_size: see @rpmsg_get_buf_payload_size(), 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 >> @@ -65,6 +66,7 @@ struct rpmsg_endpoint_ops { >> void *data, int len); >> __poll_t (*poll)(struct rpmsg_endpoint *ept, struct file *filp, >> poll_table *wait); >> + int (*get_buf_payload_size)(struct rpmsg_endpoint *ept); >> }; >> >> int rpmsg_register_device(struct rpmsg_device *rpdev); >> diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c b/drivers/rpmsg/virtio_rpmsg_bus.c >> index 5d3685bd76a2..82753e76e377 100644 >> --- a/drivers/rpmsg/virtio_rpmsg_bus.c >> +++ b/drivers/rpmsg/virtio_rpmsg_bus.c >> @@ -175,6 +175,7 @@ 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 int virtio_get_buf_payload_size(struct rpmsg_endpoint *ept); >> >> static const struct rpmsg_endpoint_ops virtio_endpoint_ops = { >> .destroy_ept = virtio_rpmsg_destroy_ept, >> @@ -184,6 +185,7 @@ static const struct rpmsg_endpoint_ops virtio_endpoint_ops = { >> .trysend = virtio_rpmsg_trysend, >> .trysendto = virtio_rpmsg_trysendto, >> .trysend_offchannel = virtio_rpmsg_trysend_offchannel, >> + .get_buf_payload_size = virtio_get_buf_payload_size, >> }; >> >> /** >> @@ -699,6 +701,15 @@ static int virtio_rpmsg_trysend_offchannel(struct rpmsg_endpoint *ept, u32 src, >> return rpmsg_send_offchannel_raw(rpdev, src, dst, data, len, false); >> } >> >> +static int virtio_get_buf_payload_size(struct rpmsg_endpoint *ept) >> +{ >> + struct rpmsg_device *rpdev = ept->rpdev; >> + struct virtio_rpmsg_channel *vch = to_virtio_rpmsg_channel(rpdev); >> + int size = vch->vrp->buf_size - sizeof(struct rpmsg_hdr); >> + >> + return size < 0 ? -EMSGSIZE : size; > > Seems that a rpmsg instance configured to not even have space for the > rpmsg_hdr in each message is rather broken. Shouldn't this be prohibited > elsewhere? yes seems that the are some useless check in code on buf_size, i will suppress the check here. there are some other instances in code...For time being the size is fixed, but good place seems to be in the rpmsg_probe probe function. i will propose a patch to clean this. Thanks, Arnaud > > Regards, > Bjorn > >> +} >> + >> static int rpmsg_recv_single(struct virtproc_info *vrp, struct device *dev, >> struct rpmsg_hdr *msg, unsigned int len) >> { >> diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h >> index 9fe156d1c018..250df2165086 100644 >> --- a/include/linux/rpmsg.h >> +++ b/include/linux/rpmsg.h >> @@ -135,6 +135,8 @@ 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); >> >> +int rpmsg_get_buf_payload_size(struct rpmsg_endpoint *ept); >> + >> #else >> >> static inline int register_rpmsg_device(struct rpmsg_device *dev) >> @@ -242,6 +244,14 @@ static inline __poll_t rpmsg_poll(struct rpmsg_endpoint *ept, >> return 0; >> } >> >> +static int rpmsg_get_buf_payload_size(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 */ >> -- >> 2.7.4 >>
