Message ID | 20210319061952.145040-1-andrew@aj.id.au (mailing list archive) |
---|---|
Headers | show |
Series | ipmi: Allow raw access to KCS devices | expand |
On Fri, Mar 19, 2021 at 01:19:30AM CDT, Andrew Jeffery wrote: >Hello, > >This series is a bit of a mix of things, but its primary purpose is to >expose BMC KCS IPMI devices to userspace in a way that enables userspace >to talk to host firmware using protocols that are not IPMI. > >v1 can be found here: > >https://lore.kernel.org/openbmc/20210219142523.3464540-1-andrew@aj.id.au/ > >Changes in v2 include: > >* A rebase onto v5.12-rc2 >* Incorporation of off-list feedback on SerIRQ configuration from > Chiawei >* Further validation on hardware for ASPEED KCS devices 2, 3 and 4 >* Lifting the existing single-open constraint of the IPMI chardev >* Fixes addressing Rob's feedback on the conversion of the ASPEED KCS > binding to dt-schema >* Fixes addressing Rob's feedback on the new aspeed,lpc-interrupts > property definition for the ASPEED KCS binding > >A new chardev device is added whose implementation exposes the Input >Data Register (IDR), Output Data Register (ODR) and Status Register >(STR) via read() and write(), and implements poll() for event >monitoring. > >The existing /dev/ipmi-kcs* chardev interface exposes the KCS devices in >a way which encoded the IPMI protocol in its behaviour. However, as >LPC[0] KCS devices give us bi-directional interrupts between the host >and a BMC with both a data and status byte, they are useful for purposes >beyond IPMI. > >As a concrete example, libmctp[1] implements a vendor-defined MCTP[2] >binding using a combination of LPC Firmware cycles for bulk data >transfer and a KCS device via LPC IO cycles for out-of-band protocol >control messages[3]. This gives a throughput improvement over the >standard KCS binding[4] while continuing to exploit the ease of setup of >the LPC bus for early boot firmware on the host processor. > >The series takes a bit of a winding path to achieve its aim: > >1. It begins with patches 1-5 put together by Chia-Wei, which I've >rebased on v5.12-rc2. These fix the ASPEED LPC bindings and other >non-KCS LPC-related ASPEED device drivers in a way that enables the >SerIRQ patches at the end of the series. With Joel's review I'm hoping >these 5 can go through the aspeed tree, and that the rest can go through >the IPMI tree. > >2. Next, patches 6-13 fairly heavily refactor the KCS support in the >IPMI part of the tree, re-architecting things such that it's possible to >support multiple chardev implementations sitting on top of the ASPEED >and Nuvoton device drivers. However, the KCS code didn't really have >great separation of concerns as it stood, so even if we disregard the >multiple-chardev support I think the cleanups are worthwhile. > >3. Patch 14 adds some interrupt management capabilities to the KCS >device drivers in preparation for patch 16, which introduces the new >"raw" KCS device interface. I'm not stoked about the device name/path, >so if people are looking to bikeshed something then feel free to lay >into that. > >4. The remaining patches switch the ASPEED KCS devicetree binding to >dt-schema, add a new interrupt property to describe the SerIRQ behaviour >of the device and finally clean up Serial IRQ support in the ASPEED KCS >driver. > >Rob: The dt-binding patches still come before the relevant driver >changes, I tried to keep the two close together in the series, hence the >bindings changes not being patches 1 and 2. > >I've exercised the series under qemu with the rainier-bmc machine plus >additional patches for KCS support[5]. I've also substituted this series in >place of a hacky out-of-tree driver that we've been using for the >libmctp stack and successfully booted the host processor under our >internal full-platform simulation tools for a Rainier system. > >Note that this work touches the Nuvoton driver as well as ASPEED's, but >I don't have the capability to test those changes or the IPMI chardev >path. Tested-by tags would be much appreciated if you can exercise one >or both. > >Please review! > >Andrew > After rebasing the series onto the OpenBMC dev-5.10 kernel (with only a tiny conflict for the addition of the ast2600 entry in ast_kcs_bmc_match) and enabling CONFIG_IPMI_KCS_BMC_CDEV_IPMI, my e3c246d4i system booted healthily and handled some basic ipmitool operations as expected. Tested-by: Zev Weiss <zweiss@equinix.com> Zev
Hi Corey, On Fri, 19 Mar 2021, at 16:49, Andrew Jeffery wrote: > Hello, > > This series is a bit of a mix of things, but its primary purpose is to > expose BMC KCS IPMI devices to userspace in a way that enables userspace > to talk to host firmware using protocols that are not IPMI. > > v1 can be found here: > > https://lore.kernel.org/openbmc/20210219142523.3464540-1-andrew@aj.id.au/ > > Changes in v2 include: > > * A rebase onto v5.12-rc2 > * Incorporation of off-list feedback on SerIRQ configuration from > Chiawei > * Further validation on hardware for ASPEED KCS devices 2, 3 and 4 > * Lifting the existing single-open constraint of the IPMI chardev > * Fixes addressing Rob's feedback on the conversion of the ASPEED KCS > binding to dt-schema > * Fixes addressing Rob's feedback on the new aspeed,lpc-interrupts > property definition for the ASPEED KCS binding > > A new chardev device is added whose implementation exposes the Input > Data Register (IDR), Output Data Register (ODR) and Status Register > (STR) via read() and write(), and implements poll() for event > monitoring. > > The existing /dev/ipmi-kcs* chardev interface exposes the KCS devices in > a way which encoded the IPMI protocol in its behaviour. However, as > LPC[0] KCS devices give us bi-directional interrupts between the host > and a BMC with both a data and status byte, they are useful for purposes > beyond IPMI. > > As a concrete example, libmctp[1] implements a vendor-defined MCTP[2] > binding using a combination of LPC Firmware cycles for bulk data > transfer and a KCS device via LPC IO cycles for out-of-band protocol > control messages[3]. This gives a throughput improvement over the > standard KCS binding[4] while continuing to exploit the ease of setup of > the LPC bus for early boot firmware on the host processor. > > The series takes a bit of a winding path to achieve its aim: > > 1. It begins with patches 1-5 put together by Chia-Wei, which I've > rebased on v5.12-rc2. These fix the ASPEED LPC bindings and other > non-KCS LPC-related ASPEED device drivers in a way that enables the > SerIRQ patches at the end of the series. With Joel's review I'm hoping > these 5 can go through the aspeed tree, and that the rest can go through > the IPMI tree. > > 2. Next, patches 6-13 fairly heavily refactor the KCS support in the > IPMI part of the tree, re-architecting things such that it's possible to > support multiple chardev implementations sitting on top of the ASPEED > and Nuvoton device drivers. However, the KCS code didn't really have > great separation of concerns as it stood, so even if we disregard the > multiple-chardev support I think the cleanups are worthwhile. > > 3. Patch 14 adds some interrupt management capabilities to the KCS > device drivers in preparation for patch 16, which introduces the new > "raw" KCS device interface. I'm not stoked about the device name/path, > so if people are looking to bikeshed something then feel free to lay > into that. > > 4. The remaining patches switch the ASPEED KCS devicetree binding to > dt-schema, add a new interrupt property to describe the SerIRQ behaviour > of the device and finally clean up Serial IRQ support in the ASPEED KCS > driver. > > Rob: The dt-binding patches still come before the relevant driver > changes, I tried to keep the two close together in the series, hence the > bindings changes not being patches 1 and 2. > > I've exercised the series under qemu with the rainier-bmc machine plus > additional patches for KCS support[5]. I've also substituted this series in > place of a hacky out-of-tree driver that we've been using for the > libmctp stack and successfully booted the host processor under our > internal full-platform simulation tools for a Rainier system. > > Note that this work touches the Nuvoton driver as well as ASPEED's, but > I don't have the capability to test those changes or the IPMI chardev > path. Tested-by tags would be much appreciated if you can exercise one > or both. > > Please review! Unfortunately the cover letter got detached from the rest of the series. Any chance you can take a look at the patches? https://lore.kernel.org/linux-arm-kernel/20210319062752.145730-1-andrew@aj.id.au/ Cheers, Andrew
On Thu, Apr 08, 2021 at 10:27:46AM +0930, Andrew Jeffery wrote: > Hi Corey, > > On Fri, 19 Mar 2021, at 16:49, Andrew Jeffery wrote: > > Hello, > > > > This series is a bit of a mix of things, but its primary purpose is to > > expose BMC KCS IPMI devices to userspace in a way that enables userspace > > to talk to host firmware using protocols that are not IPMI. > > > > v1 can be found here: > > > > https://lore.kernel.org/openbmc/20210219142523.3464540-1-andrew@aj.id.au/ > > > > Changes in v2 include: > > > > * A rebase onto v5.12-rc2 > > * Incorporation of off-list feedback on SerIRQ configuration from > > Chiawei > > * Further validation on hardware for ASPEED KCS devices 2, 3 and 4 > > * Lifting the existing single-open constraint of the IPMI chardev > > * Fixes addressing Rob's feedback on the conversion of the ASPEED KCS > > binding to dt-schema > > * Fixes addressing Rob's feedback on the new aspeed,lpc-interrupts > > property definition for the ASPEED KCS binding > > > > A new chardev device is added whose implementation exposes the Input > > Data Register (IDR), Output Data Register (ODR) and Status Register > > (STR) via read() and write(), and implements poll() for event > > monitoring. > > > > The existing /dev/ipmi-kcs* chardev interface exposes the KCS devices in > > a way which encoded the IPMI protocol in its behaviour. However, as > > LPC[0] KCS devices give us bi-directional interrupts between the host > > and a BMC with both a data and status byte, they are useful for purposes > > beyond IPMI. > > > > As a concrete example, libmctp[1] implements a vendor-defined MCTP[2] > > binding using a combination of LPC Firmware cycles for bulk data > > transfer and a KCS device via LPC IO cycles for out-of-band protocol > > control messages[3]. This gives a throughput improvement over the > > standard KCS binding[4] while continuing to exploit the ease of setup of > > the LPC bus for early boot firmware on the host processor. > > > > The series takes a bit of a winding path to achieve its aim: > > > > 1. It begins with patches 1-5 put together by Chia-Wei, which I've > > rebased on v5.12-rc2. These fix the ASPEED LPC bindings and other > > non-KCS LPC-related ASPEED device drivers in a way that enables the > > SerIRQ patches at the end of the series. With Joel's review I'm hoping > > these 5 can go through the aspeed tree, and that the rest can go through > > the IPMI tree. > > > > 2. Next, patches 6-13 fairly heavily refactor the KCS support in the > > IPMI part of the tree, re-architecting things such that it's possible to > > support multiple chardev implementations sitting on top of the ASPEED > > and Nuvoton device drivers. However, the KCS code didn't really have > > great separation of concerns as it stood, so even if we disregard the > > multiple-chardev support I think the cleanups are worthwhile. > > > > 3. Patch 14 adds some interrupt management capabilities to the KCS > > device drivers in preparation for patch 16, which introduces the new > > "raw" KCS device interface. I'm not stoked about the device name/path, > > so if people are looking to bikeshed something then feel free to lay > > into that. > > > > 4. The remaining patches switch the ASPEED KCS devicetree binding to > > dt-schema, add a new interrupt property to describe the SerIRQ behaviour > > of the device and finally clean up Serial IRQ support in the ASPEED KCS > > driver. > > > > Rob: The dt-binding patches still come before the relevant driver > > changes, I tried to keep the two close together in the series, hence the > > bindings changes not being patches 1 and 2. > > > > I've exercised the series under qemu with the rainier-bmc machine plus > > additional patches for KCS support[5]. I've also substituted this series in > > place of a hacky out-of-tree driver that we've been using for the > > libmctp stack and successfully booted the host processor under our > > internal full-platform simulation tools for a Rainier system. > > > > Note that this work touches the Nuvoton driver as well as ASPEED's, but > > I don't have the capability to test those changes or the IPMI chardev > > path. Tested-by tags would be much appreciated if you can exercise one > > or both. > > > > Please review! > > Unfortunately the cover letter got detached from the rest of the series. > > Any chance you can take a look at the patches? There were some minor concerns that were unanswered, and there really was no review by others for many of the patches. I would like this patch set, it makes some good cleanups. But I would like some more review and testing by others, if possible. I'm fairly sure it has already been done, it just needs to be documented. -corey > > https://lore.kernel.org/linux-arm-kernel/20210319062752.145730-1-andrew@aj.id.au/ > > Cheers, > > Andrew
On Thu, 8 Apr 2021, at 21:44, Corey Minyard wrote: > On Thu, Apr 08, 2021 at 10:27:46AM +0930, Andrew Jeffery wrote: > > Hi Corey, > > > > On Fri, 19 Mar 2021, at 16:49, Andrew Jeffery wrote: > > > Hello, > > > > > > This series is a bit of a mix of things, but its primary purpose is to > > > expose BMC KCS IPMI devices to userspace in a way that enables userspace > > > to talk to host firmware using protocols that are not IPMI. > > > > > > v1 can be found here: > > > > > > https://lore.kernel.org/openbmc/20210219142523.3464540-1-andrew@aj.id.au/ > > > > > > Changes in v2 include: > > > > > > * A rebase onto v5.12-rc2 > > > * Incorporation of off-list feedback on SerIRQ configuration from > > > Chiawei > > > * Further validation on hardware for ASPEED KCS devices 2, 3 and 4 > > > * Lifting the existing single-open constraint of the IPMI chardev > > > * Fixes addressing Rob's feedback on the conversion of the ASPEED KCS > > > binding to dt-schema > > > * Fixes addressing Rob's feedback on the new aspeed,lpc-interrupts > > > property definition for the ASPEED KCS binding > > > > > > A new chardev device is added whose implementation exposes the Input > > > Data Register (IDR), Output Data Register (ODR) and Status Register > > > (STR) via read() and write(), and implements poll() for event > > > monitoring. > > > > > > The existing /dev/ipmi-kcs* chardev interface exposes the KCS devices in > > > a way which encoded the IPMI protocol in its behaviour. However, as > > > LPC[0] KCS devices give us bi-directional interrupts between the host > > > and a BMC with both a data and status byte, they are useful for purposes > > > beyond IPMI. > > > > > > As a concrete example, libmctp[1] implements a vendor-defined MCTP[2] > > > binding using a combination of LPC Firmware cycles for bulk data > > > transfer and a KCS device via LPC IO cycles for out-of-band protocol > > > control messages[3]. This gives a throughput improvement over the > > > standard KCS binding[4] while continuing to exploit the ease of setup of > > > the LPC bus for early boot firmware on the host processor. > > > > > > The series takes a bit of a winding path to achieve its aim: > > > > > > 1. It begins with patches 1-5 put together by Chia-Wei, which I've > > > rebased on v5.12-rc2. These fix the ASPEED LPC bindings and other > > > non-KCS LPC-related ASPEED device drivers in a way that enables the > > > SerIRQ patches at the end of the series. With Joel's review I'm hoping > > > these 5 can go through the aspeed tree, and that the rest can go through > > > the IPMI tree. > > > > > > 2. Next, patches 6-13 fairly heavily refactor the KCS support in the > > > IPMI part of the tree, re-architecting things such that it's possible to > > > support multiple chardev implementations sitting on top of the ASPEED > > > and Nuvoton device drivers. However, the KCS code didn't really have > > > great separation of concerns as it stood, so even if we disregard the > > > multiple-chardev support I think the cleanups are worthwhile. > > > > > > 3. Patch 14 adds some interrupt management capabilities to the KCS > > > device drivers in preparation for patch 16, which introduces the new > > > "raw" KCS device interface. I'm not stoked about the device name/path, > > > so if people are looking to bikeshed something then feel free to lay > > > into that. > > > > > > 4. The remaining patches switch the ASPEED KCS devicetree binding to > > > dt-schema, add a new interrupt property to describe the SerIRQ behaviour > > > of the device and finally clean up Serial IRQ support in the ASPEED KCS > > > driver. > > > > > > Rob: The dt-binding patches still come before the relevant driver > > > changes, I tried to keep the two close together in the series, hence the > > > bindings changes not being patches 1 and 2. > > > > > > I've exercised the series under qemu with the rainier-bmc machine plus > > > additional patches for KCS support[5]. I've also substituted this series in > > > place of a hacky out-of-tree driver that we've been using for the > > > libmctp stack and successfully booted the host processor under our > > > internal full-platform simulation tools for a Rainier system. > > > > > > Note that this work touches the Nuvoton driver as well as ASPEED's, but > > > I don't have the capability to test those changes or the IPMI chardev > > > path. Tested-by tags would be much appreciated if you can exercise one > > > or both. > > > > > > Please review! > > > > Unfortunately the cover letter got detached from the rest of the series. > > > > Any chance you can take a look at the patches? > > There were some minor concerns that were unanswered, and there really > was no review by others for many of the patches. Right; I was planning to clean up the minor concerns once I'd received some more feedback. I could have done a better job of communicating that :) > > I would like this patch set, it makes some good cleanups. But I would > like some more review and testing by others, if possible. No worries. I'm trying to rope some others in to take a look. Thanks for the response. Andrew
On Thu, 8 Apr 2021 at 23:47, Andrew Jeffery <andrew@aj.id.au> wrote: > On Thu, 8 Apr 2021, at 21:44, Corey Minyard wrote: > > On Thu, Apr 08, 2021 at 10:27:46AM +0930, Andrew Jeffery wrote: > > > > 1. It begins with patches 1-5 put together by Chia-Wei, which I've > > > > rebased on v5.12-rc2. These fix the ASPEED LPC bindings and other > > > > non-KCS LPC-related ASPEED device drivers in a way that enables the > > > > SerIRQ patches at the end of the series. With Joel's review I'm hoping > > > > these 5 can go through the aspeed tree, and that the rest can go through > > > > the IPMI tree. > > > > > > > > Please review! > > > > > > Unfortunately the cover letter got detached from the rest of the series. > > > > > > Any chance you can take a look at the patches? > > > > There were some minor concerns that were unanswered, and there really > > was no review by others for many of the patches. > > Right; I was planning to clean up the minor concerns once I'd received > some more feedback. I could have done a better job of communicating > that :) I'll merge the first five through the aspeed tree this coming merge window. We have acks from the relevant maintainers. Arnd: would you prefer that this come as it's own pull request, or as part of the device tree branch? Andrew, Corey: once I've got my pull requests out I'll look at reviewing the rest of the series. Perhaps it would pay to re-send that hunk of patches Andrew with the nits fixed? Cheers, Joel
On Fri, 9 Apr 2021, at 13:37, Joel Stanley wrote: > On Thu, 8 Apr 2021 at 23:47, Andrew Jeffery <andrew@aj.id.au> wrote: > > On Thu, 8 Apr 2021, at 21:44, Corey Minyard wrote: > > > On Thu, Apr 08, 2021 at 10:27:46AM +0930, Andrew Jeffery wrote: > > > > > > 1. It begins with patches 1-5 put together by Chia-Wei, which I've > > > > > rebased on v5.12-rc2. These fix the ASPEED LPC bindings and other > > > > > non-KCS LPC-related ASPEED device drivers in a way that enables the > > > > > SerIRQ patches at the end of the series. With Joel's review I'm hoping > > > > > these 5 can go through the aspeed tree, and that the rest can go through > > > > > the IPMI tree. > > > > > > > > > > > Please review! > > > > > > > > Unfortunately the cover letter got detached from the rest of the series. > > > > > > > > Any chance you can take a look at the patches? > > > > > > There were some minor concerns that were unanswered, and there really > > > was no review by others for many of the patches. > > > > Right; I was planning to clean up the minor concerns once I'd received > > some more feedback. I could have done a better job of communicating > > that :) > > I'll merge the first five through the aspeed tree this coming merge > window. We have acks from the relevant maintainers. > > Arnd: would you prefer that this come as it's own pull request, or as > part of the device tree branch? > > Andrew, Corey: once I've got my pull requests out I'll look at > reviewing the rest of the series. Perhaps it would pay to re-send that > hunk of patches Andrew with the nits fixed? Yep; Zev has done some reviews for me so I'll address those, rebase on your tree once you've sent out the pull-req and send out a v3. Corey: Are you okay with that for now? Cheers, Andrew
On Fri, Apr 9, 2021 at 6:09 AM Joel Stanley <joel@jms.id.au> wrote: > On Thu, 8 Apr 2021 at 23:47, Andrew Jeffery <andrew@aj.id.au> wrote: > > On Thu, 8 Apr 2021, at 21:44, Corey Minyard wrote: > > > On Thu, Apr 08, 2021 at 10:27:46AM +0930, Andrew Jeffery wrote: > > > There were some minor concerns that were unanswered, and there really > > > was no review by others for many of the patches. > > > > Right; I was planning to clean up the minor concerns once I'd received > > some more feedback. I could have done a better job of communicating > > that :) > > I'll merge the first five through the aspeed tree this coming merge > window. We have acks from the relevant maintainers. > > Arnd: would you prefer that this come as it's own pull request, or as > part of the device tree branch? When you are unsure, it's almost never wrong to go for a separate branch, which gives you a chance to have a concise description of the contents in the tag. This would be particularly helpful if there are incompatible changes to the DT binding that require a justification. If you are only adding a few DT nodes to existing files, then merging these through the regular branch is probably easier. Arnd