* [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines @ 2022-10-18 2:04 ` Xiongfeng Wang 0 siblings, 0 replies; 12+ messages in thread From: Xiongfeng Wang @ 2022-10-18 2:04 UTC (permalink / raw) To: suzuki.poulose Cc: yehaiyang2, wanghuiqiang, Linux Kernel Mailing List, linux-arm-kernel@lists.infradead.org, mark.rutland, Catalin Marinas Hi, Suzuki We are testing CoreSight ETMv4.4 and TRBE recently. ETMv4.4 obsoletes memory mapped access to ETM and mandates the system registers. The following commit add driver for sysreg only devices, but it only support device tree. commit 5214b563588e8414193bd7a174c52350256942a6 coresight: etm4x: Add support for sysreg only devices ACPI machine can use 'ARMHC500' to report a ETM4x device. But the corresponding driver is etm4x_amba_driver. It needs memory resouces and doesn't support sysreg only device. Do we have some other way to use CoreSight ETMv4.4 on ACPI machines. Thanks a lot. Thanks, Xiongfeng _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 12+ messages in thread
* [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines @ 2022-10-18 2:04 ` Xiongfeng Wang 0 siblings, 0 replies; 12+ messages in thread From: Xiongfeng Wang @ 2022-10-18 2:04 UTC (permalink / raw) To: suzuki.poulose Cc: yehaiyang2, wanghuiqiang, Linux Kernel Mailing List, linux-arm-kernel@lists.infradead.org, mark.rutland, Catalin Marinas Hi, Suzuki We are testing CoreSight ETMv4.4 and TRBE recently. ETMv4.4 obsoletes memory mapped access to ETM and mandates the system registers. The following commit add driver for sysreg only devices, but it only support device tree. commit 5214b563588e8414193bd7a174c52350256942a6 coresight: etm4x: Add support for sysreg only devices ACPI machine can use 'ARMHC500' to report a ETM4x device. But the corresponding driver is etm4x_amba_driver. It needs memory resouces and doesn't support sysreg only device. Do we have some other way to use CoreSight ETMv4.4 on ACPI machines. Thanks a lot. Thanks, Xiongfeng ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines 2022-10-18 2:04 ` Xiongfeng Wang @ 2022-10-18 9:18 ` Suzuki Kuruppassery Poulose -1 siblings, 0 replies; 12+ messages in thread From: Suzuki Kuruppassery Poulose @ 2022-10-18 9:18 UTC (permalink / raw) To: Xiongfeng Wang Cc: yehaiyang2, wanghuiqiang, Linux Kernel Mailing List, linux-arm-kernel@lists.infradead.org, mark.rutland, Catalin Marinas, Anshuman Khandual Hi, Cc: Anshuman On 18/10/2022 03:04, Xiongfeng Wang wrote: > Hi, Suzuki > > We are testing CoreSight ETMv4.4 and TRBE recently. ETMv4.4 obsoletes memory > mapped access to ETM and mandates the system registers. The following commit add > driver for sysreg only devices, but it only support device tree. > commit 5214b563588e8414193bd7a174c52350256942a6 > coresight: etm4x: Add support for sysreg only devices > > ACPI machine can use 'ARMHC500' to report a ETM4x device. But the corresponding > driver is etm4x_amba_driver. It needs memory resouces and doesn't support sysreg > only device. That is true. Unfortunately, supporting this requires us to move away from the AMBA framework (at least) for ETM4x devices. This is currently developed by Anshuman. We can share it as soon as this is complete. Thanks Suzuki > > Do we have some other way to use CoreSight ETMv4.4 on ACPI machines. Thanks a lot. > > Thanks, > Xiongfeng _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines @ 2022-10-18 9:18 ` Suzuki Kuruppassery Poulose 0 siblings, 0 replies; 12+ messages in thread From: Suzuki Kuruppassery Poulose @ 2022-10-18 9:18 UTC (permalink / raw) To: Xiongfeng Wang Cc: yehaiyang2, wanghuiqiang, Linux Kernel Mailing List, linux-arm-kernel@lists.infradead.org, mark.rutland, Catalin Marinas, Anshuman Khandual Hi, Cc: Anshuman On 18/10/2022 03:04, Xiongfeng Wang wrote: > Hi, Suzuki > > We are testing CoreSight ETMv4.4 and TRBE recently. ETMv4.4 obsoletes memory > mapped access to ETM and mandates the system registers. The following commit add > driver for sysreg only devices, but it only support device tree. > commit 5214b563588e8414193bd7a174c52350256942a6 > coresight: etm4x: Add support for sysreg only devices > > ACPI machine can use 'ARMHC500' to report a ETM4x device. But the corresponding > driver is etm4x_amba_driver. It needs memory resouces and doesn't support sysreg > only device. That is true. Unfortunately, supporting this requires us to move away from the AMBA framework (at least) for ETM4x devices. This is currently developed by Anshuman. We can share it as soon as this is complete. Thanks Suzuki > > Do we have some other way to use CoreSight ETMv4.4 on ACPI machines. Thanks a lot. > > Thanks, > Xiongfeng ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines 2022-10-18 9:18 ` Suzuki Kuruppassery Poulose @ 2022-10-19 2:04 ` Xiongfeng Wang -1 siblings, 0 replies; 12+ messages in thread From: Xiongfeng Wang @ 2022-10-19 2:04 UTC (permalink / raw) To: Suzuki Kuruppassery Poulose Cc: yehaiyang2, wanghuiqiang, Linux Kernel Mailing List, linux-arm-kernel@lists.infradead.org, mark.rutland, Catalin Marinas, Anshuman Khandual Hi, Suzuki, Anshuman On 2022/10/18 17:18, Suzuki Kuruppassery Poulose wrote: > Hi, > > Cc: Anshuman > > On 18/10/2022 03:04, Xiongfeng Wang wrote: >> Hi, Suzuki >> >> We are testing CoreSight ETMv4.4 and TRBE recently. ETMv4.4 obsoletes memory >> mapped access to ETM and mandates the system registers. The following commit add >> driver for sysreg only devices, but it only support device tree. >> commit 5214b563588e8414193bd7a174c52350256942a6 >> coresight: etm4x: Add support for sysreg only devices >> >> ACPI machine can use 'ARMHC500' to report a ETM4x device. But the corresponding >> driver is etm4x_amba_driver. It needs memory resouces and doesn't support sysreg >> only device. > > That is true. Unfortunately, supporting this requires us to move away from the > AMBA framework (at least) for ETM4x devices. This is currently > developed by Anshuman. We can share it as soon as this is complete. Thanks a lot. Really appreciate ! By the way, do we have plan to add ACPI support for TRBE driver? ACPI 6.5 add a field 'TRBE Interrupt' in GICC Structure. In the beginning, I plan to add a platform device when got this IRQ, just like what SPE does in the following commit commit d24a0c7099b32b6981d7f126c45348e381718350 arm_pmu: acpi: spe: Add initial MADT/SPE probing But it seems that TRBE still needs _DSD method to report the links(input port and output port). Do you have some other advices? Thanks a lot. Thanks Xiongfeng > > Thanks > Suzuki > >> >> Do we have some other way to use CoreSight ETMv4.4 on ACPI machines. Thanks a >> lot. >> >> Thanks, >> Xiongfeng > > > . _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines @ 2022-10-19 2:04 ` Xiongfeng Wang 0 siblings, 0 replies; 12+ messages in thread From: Xiongfeng Wang @ 2022-10-19 2:04 UTC (permalink / raw) To: Suzuki Kuruppassery Poulose Cc: yehaiyang2, wanghuiqiang, Linux Kernel Mailing List, linux-arm-kernel@lists.infradead.org, mark.rutland, Catalin Marinas, Anshuman Khandual Hi, Suzuki, Anshuman On 2022/10/18 17:18, Suzuki Kuruppassery Poulose wrote: > Hi, > > Cc: Anshuman > > On 18/10/2022 03:04, Xiongfeng Wang wrote: >> Hi, Suzuki >> >> We are testing CoreSight ETMv4.4 and TRBE recently. ETMv4.4 obsoletes memory >> mapped access to ETM and mandates the system registers. The following commit add >> driver for sysreg only devices, but it only support device tree. >> commit 5214b563588e8414193bd7a174c52350256942a6 >> coresight: etm4x: Add support for sysreg only devices >> >> ACPI machine can use 'ARMHC500' to report a ETM4x device. But the corresponding >> driver is etm4x_amba_driver. It needs memory resouces and doesn't support sysreg >> only device. > > That is true. Unfortunately, supporting this requires us to move away from the > AMBA framework (at least) for ETM4x devices. This is currently > developed by Anshuman. We can share it as soon as this is complete. Thanks a lot. Really appreciate ! By the way, do we have plan to add ACPI support for TRBE driver? ACPI 6.5 add a field 'TRBE Interrupt' in GICC Structure. In the beginning, I plan to add a platform device when got this IRQ, just like what SPE does in the following commit commit d24a0c7099b32b6981d7f126c45348e381718350 arm_pmu: acpi: spe: Add initial MADT/SPE probing But it seems that TRBE still needs _DSD method to report the links(input port and output port). Do you have some other advices? Thanks a lot. Thanks Xiongfeng > > Thanks > Suzuki > >> >> Do we have some other way to use CoreSight ETMv4.4 on ACPI machines. Thanks a >> lot. >> >> Thanks, >> Xiongfeng > > > . ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines 2022-10-19 2:04 ` Xiongfeng Wang @ 2022-10-20 16:03 ` Suzuki K Poulose -1 siblings, 0 replies; 12+ messages in thread From: Suzuki K Poulose @ 2022-10-20 16:03 UTC (permalink / raw) To: Xiongfeng Wang Cc: yehaiyang2, wanghuiqiang, Linux Kernel Mailing List, linux-arm-kernel@lists.infradead.org, mark.rutland, Catalin Marinas, Anshuman Khandual Hi On 19/10/2022 03:04, Xiongfeng Wang wrote: > Hi, Suzuki, Anshuman > > On 2022/10/18 17:18, Suzuki Kuruppassery Poulose wrote: >> Hi, >> >> Cc: Anshuman >> >> On 18/10/2022 03:04, Xiongfeng Wang wrote: >>> Hi, Suzuki >>> >>> We are testing CoreSight ETMv4.4 and TRBE recently. ETMv4.4 obsoletes memory >>> mapped access to ETM and mandates the system registers. The following commit add >>> driver for sysreg only devices, but it only support device tree. >>> commit 5214b563588e8414193bd7a174c52350256942a6 >>> coresight: etm4x: Add support for sysreg only devices >>> >>> ACPI machine can use 'ARMHC500' to report a ETM4x device. But the corresponding >>> driver is etm4x_amba_driver. It needs memory resouces and doesn't support sysreg >>> only device. >> >> That is true. Unfortunately, supporting this requires us to move away from the >> AMBA framework (at least) for ETM4x devices. This is currently >> developed by Anshuman. We can share it as soon as this is complete. > > Thanks a lot. Really appreciate ! > By the way, do we have plan to add ACPI support for TRBE driver? ACPI 6.5 add a Yes, this is again in our pipeline. But, without the ETE support, TRBE is literally unusable. So, this will follow the ETE/ETMv4 sysreg ACPI support. > field 'TRBE Interrupt' in GICC Structure. In the beginning, I plan to add a > platform device when got this IRQ, just like what SPE does in the following commit > commit d24a0c7099b32b6981d7f126c45348e381718350 > arm_pmu: acpi: spe: Add initial MADT/SPE probing > But it seems that TRBE still needs _DSD method to report the links(input port > and output port). Do you have some other advices? Thanks a lot. TRBE doesn't need to specify the input/output ports. It is a per-CPU sink and the TRBE driver registers it as such for each CPU that it probes. Suzuki _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines @ 2022-10-20 16:03 ` Suzuki K Poulose 0 siblings, 0 replies; 12+ messages in thread From: Suzuki K Poulose @ 2022-10-20 16:03 UTC (permalink / raw) To: Xiongfeng Wang Cc: yehaiyang2, wanghuiqiang, Linux Kernel Mailing List, linux-arm-kernel@lists.infradead.org, mark.rutland, Catalin Marinas, Anshuman Khandual Hi On 19/10/2022 03:04, Xiongfeng Wang wrote: > Hi, Suzuki, Anshuman > > On 2022/10/18 17:18, Suzuki Kuruppassery Poulose wrote: >> Hi, >> >> Cc: Anshuman >> >> On 18/10/2022 03:04, Xiongfeng Wang wrote: >>> Hi, Suzuki >>> >>> We are testing CoreSight ETMv4.4 and TRBE recently. ETMv4.4 obsoletes memory >>> mapped access to ETM and mandates the system registers. The following commit add >>> driver for sysreg only devices, but it only support device tree. >>> commit 5214b563588e8414193bd7a174c52350256942a6 >>> coresight: etm4x: Add support for sysreg only devices >>> >>> ACPI machine can use 'ARMHC500' to report a ETM4x device. But the corresponding >>> driver is etm4x_amba_driver. It needs memory resouces and doesn't support sysreg >>> only device. >> >> That is true. Unfortunately, supporting this requires us to move away from the >> AMBA framework (at least) for ETM4x devices. This is currently >> developed by Anshuman. We can share it as soon as this is complete. > > Thanks a lot. Really appreciate ! > By the way, do we have plan to add ACPI support for TRBE driver? ACPI 6.5 add a Yes, this is again in our pipeline. But, without the ETE support, TRBE is literally unusable. So, this will follow the ETE/ETMv4 sysreg ACPI support. > field 'TRBE Interrupt' in GICC Structure. In the beginning, I plan to add a > platform device when got this IRQ, just like what SPE does in the following commit > commit d24a0c7099b32b6981d7f126c45348e381718350 > arm_pmu: acpi: spe: Add initial MADT/SPE probing > But it seems that TRBE still needs _DSD method to report the links(input port > and output port). Do you have some other advices? Thanks a lot. TRBE doesn't need to specify the input/output ports. It is a per-CPU sink and the TRBE driver registers it as such for each CPU that it probes. Suzuki ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines 2022-10-18 9:18 ` Suzuki Kuruppassery Poulose @ 2022-10-19 8:46 ` Russell King (Oracle) -1 siblings, 0 replies; 12+ messages in thread From: Russell King (Oracle) @ 2022-10-19 8:46 UTC (permalink / raw) To: Suzuki Kuruppassery Poulose Cc: Xiongfeng Wang, yehaiyang2, wanghuiqiang, Linux Kernel Mailing List, linux-arm-kernel@lists.infradead.org, mark.rutland, Catalin Marinas, Anshuman Khandual On Tue, Oct 18, 2022 at 10:18:08AM +0100, Suzuki Kuruppassery Poulose wrote: > That is true. Unfortunately, supporting this requires us to move away from > the AMBA framework (at least) for ETM4x devices. This is currently > developed by Anshuman. We can share it as soon as this is complete. Can we not find a way to create AMBA devices from ACPI? -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines @ 2022-10-19 8:46 ` Russell King (Oracle) 0 siblings, 0 replies; 12+ messages in thread From: Russell King (Oracle) @ 2022-10-19 8:46 UTC (permalink / raw) To: Suzuki Kuruppassery Poulose Cc: Xiongfeng Wang, yehaiyang2, wanghuiqiang, Linux Kernel Mailing List, linux-arm-kernel@lists.infradead.org, mark.rutland, Catalin Marinas, Anshuman Khandual On Tue, Oct 18, 2022 at 10:18:08AM +0100, Suzuki Kuruppassery Poulose wrote: > That is true. Unfortunately, supporting this requires us to move away from > the AMBA framework (at least) for ETM4x devices. This is currently > developed by Anshuman. We can share it as soon as this is complete. Can we not find a way to create AMBA devices from ACPI? -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines 2022-10-19 8:46 ` Russell King (Oracle) @ 2022-10-19 9:28 ` Suzuki K Poulose -1 siblings, 0 replies; 12+ messages in thread From: Suzuki K Poulose @ 2022-10-19 9:28 UTC (permalink / raw) To: Russell King (Oracle) Cc: Xiongfeng Wang, yehaiyang2, wanghuiqiang, Linux Kernel Mailing List, linux-arm-kernel@lists.infradead.org, mark.rutland, Catalin Marinas, Anshuman Khandual Hi Russell On 19/10/2022 09:46, Russell King (Oracle) wrote: > On Tue, Oct 18, 2022 at 10:18:08AM +0100, Suzuki Kuruppassery Poulose wrote: >> That is true. Unfortunately, supporting this requires us to move away from >> the AMBA framework (at least) for ETM4x devices. This is currently >> developed by Anshuman. We can share it as soon as this is complete. > > Can we not find a way to create AMBA devices from ACPI? > There is a way today and that is how the AMBA devices (including ETMv4) work. But, the problem is ETM with system register access are not AMBA devices. On a DT based system, they have different compatible and are created as platform devices. But on ACPI, there is a single HID (which makes sense, because they both are ETM devices). Now, if the instance has memory resource, we need to use the AMBA hook, but otherwise fall back to the platform device driver. And this is not reliable, depending on which driver gets to the scan hook first. Also, another reason behind moving away from AMBA, in general is: we need to explicitly add PIDs of all new CPU ETMs to the driver to be able to probe them successfully. This doesn't work very well for older kernels running on newer platforms. Even now the list of PIDs is not complete and that would go on forever. And the "party bag" of this change is the runtime power managment on ACPI platforms, that works out of the box for platform devices. Thanks Suzuki _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel ^ permalink raw reply [flat|nested] 12+ messages in thread
* Re: [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines @ 2022-10-19 9:28 ` Suzuki K Poulose 0 siblings, 0 replies; 12+ messages in thread From: Suzuki K Poulose @ 2022-10-19 9:28 UTC (permalink / raw) To: Russell King (Oracle) Cc: Xiongfeng Wang, yehaiyang2, wanghuiqiang, Linux Kernel Mailing List, linux-arm-kernel@lists.infradead.org, mark.rutland, Catalin Marinas, Anshuman Khandual Hi Russell On 19/10/2022 09:46, Russell King (Oracle) wrote: > On Tue, Oct 18, 2022 at 10:18:08AM +0100, Suzuki Kuruppassery Poulose wrote: >> That is true. Unfortunately, supporting this requires us to move away from >> the AMBA framework (at least) for ETM4x devices. This is currently >> developed by Anshuman. We can share it as soon as this is complete. > > Can we not find a way to create AMBA devices from ACPI? > There is a way today and that is how the AMBA devices (including ETMv4) work. But, the problem is ETM with system register access are not AMBA devices. On a DT based system, they have different compatible and are created as platform devices. But on ACPI, there is a single HID (which makes sense, because they both are ETM devices). Now, if the instance has memory resource, we need to use the AMBA hook, but otherwise fall back to the platform device driver. And this is not reliable, depending on which driver gets to the scan hook first. Also, another reason behind moving away from AMBA, in general is: we need to explicitly add PIDs of all new CPU ETMs to the driver to be able to probe them successfully. This doesn't work very well for older kernels running on newer platforms. Even now the list of PIDs is not complete and that would go on forever. And the "party bag" of this change is the runtime power managment on ACPI platforms, that works out of the box for platform devices. Thanks Suzuki ^ permalink raw reply [flat|nested] 12+ messages in thread
end of thread, other threads:[~2022-10-20 16:09 UTC | newest] Thread overview: 12+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2022-10-18 2:04 [Question] Question about supporting sysreg only CoreSight ETMv4.4 on ACPI machines Xiongfeng Wang 2022-10-18 2:04 ` Xiongfeng Wang 2022-10-18 9:18 ` Suzuki Kuruppassery Poulose 2022-10-18 9:18 ` Suzuki Kuruppassery Poulose 2022-10-19 2:04 ` Xiongfeng Wang 2022-10-19 2:04 ` Xiongfeng Wang 2022-10-20 16:03 ` Suzuki K Poulose 2022-10-20 16:03 ` Suzuki K Poulose 2022-10-19 8:46 ` Russell King (Oracle) 2022-10-19 8:46 ` Russell King (Oracle) 2022-10-19 9:28 ` Suzuki K Poulose 2022-10-19 9:28 ` Suzuki K Poulose
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.