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 :). > > 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()/ 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 */ >>
