Hi Suman, On 1/15/20 12:40 AM, Suman Anna wrote: > Hi Arnaud, > > On 1/13/20 7:19 AM, Arnaud POULIQUEN wrote: >> Hi Bjorn, Suman, >> >> Gentleman reminder :) > > Thanks for the revised version, and very sorry about the delay. Only > one minor nit that you missed from my comments the v6 rpmsg-tty series > [1], otherwise I am good with the changes. See below. > > FWIW, I have already been using this patch on our downstream 2020 LTS > based kernel and eliminate the the need to expose the virtio_rpmsg's > rpmsg_hdr to rpmsg client drivers :). Right without this API the client needs also to know the RPMSG buffer size to compute the MTU. > >> >> Thank in advance, >> >> Arnaud >> >> On 11/13/19 6:22 PM, Arnaud Pouliquen wrote: >>> Return the rpmsg buffer MTU for sending message, so rpmsg users >>> can split a long message in several sub rpmsg buffers. >>> >>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@xxxxxx> >>> --- >>> V1 to V2 >>> >>> V1 patch:https://lore.kernel.org/patchwork/patch/1124684/ >>> - Change patch title, >>> - as not solution today to support MTU on GLINK make ops optional, >>> RPMsg client API returns -ENOTSUPP in this case, >>> - suppress smd and glink patches. >>> --- >>> drivers/rpmsg/rpmsg_core.c | 21 +++++++++++++++++++++ >>> drivers/rpmsg/rpmsg_internal.h | 2 ++ >>> drivers/rpmsg/virtio_rpmsg_bus.c | 10 ++++++++++ >>> 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 e330ec4dfc33..a6ef54c4779a 100644 >>> --- a/drivers/rpmsg/rpmsg_core.c >>> +++ b/drivers/rpmsg/rpmsg_core.c >>> @@ -283,6 +283,27 @@ 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 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 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 3fc83cd50e98..0e56e046f5c6 100644 >>> --- a/drivers/rpmsg/rpmsg_internal.h >>> +++ b/drivers/rpmsg/rpmsg_internal.h >>> @@ -47,6 +47,7 @@ struct rpmsg_device_ops { >>> * @trysendto: see @rpmsg_trysendto(), optional >>> * @trysend_offchannel: see @rpmsg_trysend_offchannel(), optional >>> * @poll: see @rpmsg_poll(), optional >>> + * @get_mtu: see @get_mpu(), optional > > In the description for the ops, 'mpu' is a typo. My earlier comment was > essentially, > %s/see @get_mpu()/see @rpmsg_get_mtu()/ Sorry, completly missed it i sent a v3 Thanks, Arnaud > > regards > Suman > > [1] https://patchwork.kernel.org/patch/11130209/ > >>> * >>> * Indirection table for the operations that a rpmsg backend should implement. >>> * In addition to @destroy_ept, the backend must at least implement @send and >>> @@ -66,6 +67,7 @@ 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); >>> }; >>> >>> 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 376ebbf880d6..6e48fdf24555 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 ssize_t virtio_rpmsg_get_mtu(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_mtu = virtio_rpmsg_get_mtu, >>> }; >>> >>> /** >>> @@ -699,6 +701,14 @@ 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) >>> { >>> diff --git a/include/linux/rpmsg.h b/include/linux/rpmsg.h >>> index 9fe156d1c018..88d7892ca93d 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); >>> >>> +ssize_t rpmsg_get_mtu(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 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 */ >>> >
