On 10/3/23 10:28 AM, Divin Raj wrote: > Hello, > > Thanks for all review comments. > It makes sense to incorporate a variable-length buffer size. However, we > still require an implementation that can successfully achieve this objective. > > We will be investigating this matter and will return with a feasible solution.
Thanks. Here is the previous effort: Series: "Enhance virtio rpmsg bus driver buffer allocation" https://lore.kernel.org/all/1548949280-31794-1-git-send-email-xiaoxi...@xiaomi.com/ There was discussion to revive the patch and the activity is still pending. This can be good start if we want to achieve it. Thanks, Tanmay > > Thanks, > > On 9/28/23 5:10 PM, Tanmay Shah wrote: > > Hello, > > Thanks for your patch. > > Instead of having this in Kconfig, It's better to have buffer size decided > dynamically. Probably by resource-table. > > We still need implementation that achieves that goal. Meanwhile I think it's > best to keep buffer size fixed. > > Thanks. > > On 9/28/23 10:38 AM, Divin Raj wrote: > > > > CAUTION: This message has originated from an External Source. Please use > proper judgment and caution when opening attachments, clicking links, or > responding to this email. > > > From: Peter Hoyes <peter.ho...@arm.com><mailto:peter.ho...@arm.com> > > Replace the MAX_RPMSG_BUF_SIZE and MAX_RPMSG_NUM_BUFS #define in > virtio_rpmsg_bus.c with the Kconfig parameters CONFIG_RPMSG_VIRTIO_BUF_SIZE > and CONFIG_RPMSG_VIRTIO_MAX_NUM_BUFS, allowing user-provided customization. > > Making both the number of buffers and size configurable facilitates aligning > memory requirements between vdev-buffer and vdev-vrings for client drivers > that require larger buffer sizes, for example. > > Signed-off-by: Peter Hoyes <peter.ho...@arm.com><mailto:peter.ho...@arm.com> > Signed-off-by: Divin Raj <divin....@arm.com><mailto:divin....@arm.com> > --- > drivers/rpmsg/Kconfig | 23 +++++++++++++++++++++++ > drivers/rpmsg/virtio_rpmsg_bus.c | 27 +++------------------------ > 2 files changed, 26 insertions(+), 24 deletions(-) > > diff --git a/drivers/rpmsg/Kconfig b/drivers/rpmsg/Kconfig > index d3795860f5c0..677f4a1ac8bb 100644 > --- a/drivers/rpmsg/Kconfig > +++ b/drivers/rpmsg/Kconfig > @@ -81,4 +81,27 @@ config RPMSG_VIRTIO > select RPMSG_NS > select VIRTIO > > +config RPMSG_VIRTIO_MAX_BUF_SIZE > + int "Virtio RPMSG max buffer size (in bytes)" > + default 512 > + depends on RPMSG_VIRTIO > + help > + This option allows you to configure the maximum buffer size (in > bytes) > + for Virtio RPMSG communications. The number of buffers will be > computed > + based on the number of buffers (CONFIG_RPMSG_VIRTIO_MAX_NUM_BUFS) > + supported by the vring. By default, it supports up to a maximum of > 512 > + buffers (256 in each direction). Each buffer consists of 16 bytes > for the > + message header and the remaining bytes for the payload.The default > values > + will utilize a maximum total space of 256KB for the buffers. > + > +config RPMSG_VIRTIO_MAX_NUM_BUFS > + int "Virtio RPMSG max buffer count (even number for TX and Rx)" > + default 512 > + depends on RPMSG_VIRTIO > + help > + This option allows you to configure the maximum number of buffers > used > + for Virtio RPMSG communication. By default, it supports up to a > maximum > + of 512 buffers (256 in each direction). Please note that this value > + should be an even number, as it accounts for both transmit (TX) and > + receive (Rx) buffers. > endmenu > diff --git a/drivers/rpmsg/virtio_rpmsg_bus.c > b/drivers/rpmsg/virtio_rpmsg_bus.c > index 905ac7910c98..87a9a4fa30e0 100644 > --- a/drivers/rpmsg/virtio_rpmsg_bus.c > +++ b/drivers/rpmsg/virtio_rpmsg_bus.c > @@ -109,27 +109,6 @@ 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, > @@ -902,12 +881,12 @@ static int rpmsg_probe(struct virtio_device *vdev) > virtqueue_get_vring_size(vrp->svq)); > > /* we need less buffers if vrings are small */ > - if (virtqueue_get_vring_size(vrp->rvq) < MAX_RPMSG_NUM_BUFS / 2) > + if (virtqueue_get_vring_size(vrp->rvq) < > CONFIG_RPMSG_VIRTIO_MAX_NUM_BUFS / 2) > vrp->num_bufs = virtqueue_get_vring_size(vrp->rvq) * 2; > else > - vrp->num_bufs = MAX_RPMSG_NUM_BUFS; > + vrp->num_bufs = CONFIG_RPMSG_VIRTIO_MAX_NUM_BUFS; > > - vrp->buf_size = MAX_RPMSG_BUF_SIZE; > + vrp->buf_size = CONFIG_RPMSG_VIRTIO_MAX_BUF_SIZE; > > total_buf_space = vrp->num_bufs * vrp->buf_size; > > -- > 2.25.1 > > > > IMPORTANT NOTICE: The contents of this email and any attachments are > confidential and may also be privileged. If you are not the intended > recipient, please notify the sender immediately and do not disclose the > contents to any other person, use it for any purpose, or store or copy the > information in any medium. Thank you. >
