Openamp-rp May 2023

openamp-rp@lists.openampproject.org

4 participants
3 discussions

Re: [RFC]: Variable RpMsg buffer size in Linux Kernel

by Arnaud POULIQUEN

ST Restricted > -----Original Message----- > From: Mathieu Poirier <mathieu.poirier(a)linaro.org> > Sent: Saturday, May 20, 2023 1:00 AM > To: Bill Mills <bill.mills(a)linaro.org> > Cc: Shah, Tanmay <tanmay.shah(a)amd.com>; ed.mooring(a)gmail.com; > tammy.leino(a)siemens.com; Arnaud POULIQUEN > <arnaud.pouliquen(a)st.com>; openamp-rp(a)lists.openampproject.org > Subject: Re: [RFC]: Variable RpMsg buffer size in Linux Kernel > > On Thu, 18 May 2023 at 10:27, Bill Mills <bill.mills(a)linaro.org> wrote: > > > > > > > > On 5/18/23 12:00 PM, Shah, Tanmay wrote: > > > Hi all, > > > > > > As of now, rpmsg buffer size is decided by RPMSG_BUF_SIZE macro. > > > This is fixed to 512 bytes. > > > > > > If platform needs to send larger than 512 bytes of payload, then the > > > payload needs to be split between multiple buffers. > > > > > > Instead of that, it would be useful if platform can configure > > > RPMSG_BUF_SIZE somehow. > > > > > > There are multiple options to achieve this: > > > > > > 1. Move RPMSG_BUF_SIZE to Kconfig -> The approach is not accepted as > > > single kernel may not work for all platforms. > > > 2. Keep device-tree property that mentions rpmsg buffer size. > > > 1. Something in dts: “rpmsg-buf-size = <512>” > > > 2. This way one kernel can work for all the platforms. If property > > > is not mentioned, then we fallback to default size of 512 bytes. > > > 3. Dynamic buffer allocation > > > 1. This effort was done previously. Please refer to following > > > discussion from kernel and openamp library: > > > > > > i.Openamp library: https://github.com/OpenAMP/open-amp/pull/155 > > > <https://github.com/OpenAMP/open-amp/pull/155> > > > > > > 1. Conclusion: > > > > > > https://github.com/OpenAMP/open-amp/issues/322#issuecomment- > 98657382 > > > 8 > > > <https://github.com/OpenAMP/open-amp/issues/322#issuecomment- > 9865738 > > > 28> > > > > > > ii.Kernel: > > > https://patchwork.kernel.org/project/linux-remoteproc/cover/15489492 > > > 80-31794-1-git-send-email-xiaoxiang(a)xiaomi.com/ > > > <https://patchwork.kernel.org/project/linux-remoteproc/cover/1548949 > > > 280-31794-1-git-send-email-xiaoxiang(a)xiaomi.com/> > > > > > > > Lore link to same: > > https://lore.kernel.org/lkml/20190605043452.GI22737@tuxbook-pro/T/ > > > > I saw nothing in this thread that I would call a rejection. > > > > It made the size choice based on the virtio config space which could > > come from firmware resource table now or virtio device config space if > > using virtio-mmio etc. > > > > Bjorn did point out that a system where each side allocated its own > > buffers of whatever size desired would be more flexible but: > > * did not object to this step > > * that would be a pretty big departure from what we have not and we > > would still need to negotiate its use. > > > > The biggest issues I saw with the patch series was the details of how > > it did the config. That could have been fixed with a bit more effort. > > > > I would vote we just resurrect this patch set and clean it up rather > > than going down the DTS route. > > > > I agree - I did not find anything controversial in that patchset either. We can > start with that and later supplement with the DTS if needed. Also in favor of this approach Regards, Arnaud > > > Bill > > > > > 2. As part of this, RPMSG_BUF_SIZE is configurable on library side, > > > but not on kernel side. > > > > > > If it looks reasonable to go with approach 2 without side-effects, I > > > can develop and send the patch. > > > > > > Thanks, > > > > > > Tanmay > > > > > > > -- > > Bill Mills > > Principal Technical Consultant, Linaro > > +1-240-643-0836 > > TZ: US Eastern > > Work Schedule: Tues/Wed/Thur

12 months

[OpenAMP/open-amp] 1697a1: apps: zynqmp: Add Versal_net IPI values.

by Arnaud Pouliquen

Branch: refs/heads/main Home: https://github.com/OpenAMP/open-amp Commit: 1697a15f477578104e81092406fb2318a56e2f72 https://github.com/OpenAMP/open-amp/commit/1697a15f477578104e81092406fb2318… Author: Ben Levinsky <ben.levinsky(a)amd.com> Date: 2023-05-22 (Mon, 22 May 2023) Changed paths: M apps/machine/zynqmp/platform_info.c Log Message: ----------- apps: zynqmp: Add Versal_net IPI values. Enable Linux demos to run on Versal_net by updating the IPI values that are specific to this hardware platform. Signed-off-by: Ben Levinsky <ben.levinsky(a)amd.com>

12 months

Re: [RFC]: Variable RpMsg buffer size in Linux Kernel

by Bill Mills

On 5/18/23 12:00 PM, Shah, Tanmay wrote: > Hi all, > > As of now, rpmsg buffer size is decided by RPMSG_BUF_SIZE macro. This is > fixed to 512 bytes. > > If platform needs to send larger than 512 bytes of payload, then the > payload needs to be split between multiple buffers. > > Instead of that, it would be useful if platform can configure > RPMSG_BUF_SIZE somehow. > > There are multiple options to achieve this: > > 1. Move RPMSG_BUF_SIZE to Kconfig -> The approach is not accepted as > single kernel may not work for all platforms. > 2. Keep device-tree property that mentions rpmsg buffer size. > 1. Something in dts: “rpmsg-buf-size = <512>” > 2. This way one kernel can work for all the platforms. If property > is not mentioned, then we fallback to default size of 512 bytes. > 3. Dynamic buffer allocation > 1. This effort was done previously. Please refer to following > discussion from kernel and openamp library: > > i.Openamp library: https://github.com/OpenAMP/open-amp/pull/155 > <https://github.com/OpenAMP/open-amp/pull/155> > > 1. Conclusion: > https://github.com/OpenAMP/open-amp/issues/322#issuecomment-986573828 <https://github.com/OpenAMP/open-amp/issues/322#issuecomment-986573828> > > ii.Kernel: > https://patchwork.kernel.org/project/linux-remoteproc/cover/1548949280-3179… <https://patchwork.kernel.org/project/linux-remoteproc/cover/1548949280-3179…> > Lore link to same: https://lore.kernel.org/lkml/20190605043452.GI22737@tuxbook-pro/T/ I saw nothing in this thread that I would call a rejection. It made the size choice based on the virtio config space which could come from firmware resource table now or virtio device config space if using virtio-mmio etc. Bjorn did point out that a system where each side allocated its own buffers of whatever size desired would be more flexible but: * did not object to this step * that would be a pretty big departure from what we have not and we would still need to negotiate its use. The biggest issues I saw with the patch series was the details of how it did the config. That could have been fixed with a bit more effort. I would vote we just resurrect this patch set and clean it up rather than going down the DTS route. Bill > 2. As part of this, RPMSG_BUF_SIZE is configurable on library side, > but not on kernel side. > > If it looks reasonable to go with approach 2 without side-effects, I can > develop and send the patch. > > Thanks, > > Tanmay > -- Bill Mills Principal Technical Consultant, Linaro +1-240-643-0836 TZ: US Eastern Work Schedule: Tues/Wed/Thur

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Openamp-rp May 2023