From: hanjun.guo@linaro.org (Hanjun Guo)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 19/19] Documentation: ACPI for ARM64
Date: Fri, 15 Aug 2014 17:09:42 +0800 [thread overview]
Message-ID: <53EDCE56.6020702@linaro.org> (raw)
In-Reply-To: <20140814102723.GB9039@arm.com>
On 2014-8-14 18:27, Catalin Marinas wrote:
> On Thu, Aug 14, 2014 at 04:21:25AM +0100, Hanjun Guo wrote:
>> On 2014-8-14 7:41, Rafael J. Wysocki wrote:
>>> On Tuesday, August 12, 2014 07:23:47 PM Catalin Marinas wrote:
>>>> If we consider ACPI unusable on ARM but we still want to start merging
>>>> patches, we should rather make the config option depend on BROKEN
>>>> (though if it is that unusable that no real platform can use it, I would
>>>> rather not merge it at all at this stage).
>>>
>>> I agree here.
>>>
>>> I would recommend creating a separate branch for that living outside of the
>>> mainline kernel and merging it when there are real users.
>>
>> Real users will coming soon, we already tested this patch set on real hardware
>> (ARM64 Juno platform),
>
> I don't consider Juno a server platform ;) (but it's good enough for
> development).
>
>> and I think ARM64 server chips and platforms will show up before 3.18
>> is released.
>
> That's what I've heard/seen. The questions I have are (a) whether
> current ACPI patchset is enough to successfully run Linux on such
> _hardware_ platform (maybe not fully optimised, for example just WFI
> cpuidle) and (b) whether we still want to mandate a DT in the kernel for
> such platforms.
For (a), this patch set is only for ARM64 core, not including platform
specific device drivers, it will be covered by the binding of _DSD or
explicit definition of PNP ID/ACPI ID(s).
>
> Given the answer to (a) and what other features are needed, we may or
> may not mandate (b). We were pretty clear few months ago that (b) is
> still required but at the time we were only openly talking about ACPI
> 5.0 which was lacking many features. I think we need to revisit that
> position based on how usable ACPI 5.1 for ARM (and current kernel
> implementation) is. Would you mind elaborating what an ACPI-only
> platform miss?
Do you mean something still missing? We still miss some features for
ARM in ACPI, but I think they are not critical, here is the list I can
remember:
- ITS for GICv3/4;
- SMMU support;
- CPU idle control.
For ACPI 5.1, it fixes many problems for ARM:
- weak definition for GIC, so we introduce visualization, v2m and
part of GICv3/4 (redistributors) support.
- No support for PSCI. Fix it to support PSCI 0.2+;
- Not support for Always-on timer and SBSA-L1 watchdog.
- How to describe device properties, so _DSD is introduced for
device probe.
>
> I would expect a new server platform designed with ACPI in mind to
> require minimal SoC specific code, so we may only see a few patches
> under drivers/ for such platforms adding ACPI-specific probing (possibly
> new drivers as well if it's a new component).
>
>> For this patch set, DT is the first class citizen at now:
>>
>> a) We can always set CONFIG_ACPI as off in Kconfig, and use DT only;
>
> Not just off but, based on maturity, depend on EXPERT.
Ok. And don't set ACPI default off (pass acpi=on to enable it)?
>
>> b) Even if we set CONFIG_ACPI=Y, we also can use DT as normal:
>>
>> - Pass DT blob without (valid) ACPI tables (just as we boot the kernel now),
>> ACPI will disabled in the very early stage and FDT will still to be
>> unflattened, so will not break DT booting.
>>
>> - We can pass ACPI=off to disable ACPI and use DT even if we got valid
>> ACPI tables (in the v1 patch set);
>>
>> So it is safe for people who want to use DT, and didn't change any behavior
>> of DT booting except some extra test of if(acpi_disabled).
>
> But should we require SoC firmware to provide both valid DT and ACPI
> tables so that the user can decide which one to select at boot-time?
No, I think only one of them should be provided on real platforms.
Thanks
Hanjun
next prev parent reply other threads:[~2014-08-15 9:09 UTC|newest]
Thread overview: 131+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-07-24 13:00 [PATCH 00/19] Introduce ACPI for ARM64 based on ACPI 5.1 Hanjun Guo
2014-07-24 13:00 ` [PATCH 01/19] ARM64 / ACPI: Get RSDP and ACPI boot-time tables Hanjun Guo
2014-07-28 18:29 ` Sudeep Holla
2014-07-28 22:49 ` Graeme Gregory
2014-07-29 8:49 ` Sudeep Holla
2014-07-29 13:08 ` Hanjun Guo
2014-07-29 13:50 ` Sudeep Holla
2014-07-29 14:07 ` Hanjun Guo
2014-07-28 18:30 ` Sudeep Holla
2014-07-24 13:00 ` [PATCH 02/19] ARM64 / ACPI: Introduce early_param for "acpi" Hanjun Guo
2014-07-28 18:35 ` Sudeep Holla
2014-07-29 13:10 ` Hanjun Guo
2014-07-24 13:00 ` [PATCH 03/19] ARM64 / ACPI: Introduce lowlevel suspend function Hanjun Guo
2014-07-24 15:34 ` Mark Rutland
2014-07-25 10:42 ` Hanjun Guo
2014-07-28 18:28 ` Sudeep Holla
2014-07-29 13:00 ` Hanjun Guo
2014-07-24 13:00 ` [PATCH 04/19] ARM64 / ACPI: Introduce arch_fix_phys_package_id() for cpu topology Hanjun Guo
2014-07-24 14:43 ` Mark Brown
2014-07-25 10:32 ` Hanjun Guo
2014-07-28 18:51 ` Sudeep Holla
2014-08-01 6:35 ` Hanjun Guo
2014-08-01 10:48 ` Sudeep Holla
2014-07-24 13:00 ` [PATCH 05/19] ARM64 / ACPI: Make PCI optional for ACPI on ARM64 Hanjun Guo
2014-07-24 21:57 ` Naresh Bhat
2014-07-29 16:40 ` Sudeep Holla
2014-07-24 13:00 ` [PATCH 06/19] ARM64 / ACPI: Parse FADT table to get PSCI flags for PSCI init Hanjun Guo
2014-07-29 16:40 ` Sudeep Holla
2014-07-31 3:53 ` Hanjun Guo
2014-07-31 4:22 ` Olof Johansson
2014-07-31 10:23 ` Hanjun Guo
2014-08-20 15:02 ` Grant Likely
2014-08-20 15:00 ` Grant Likely
2014-08-20 15:29 ` Catalin Marinas
2014-08-20 15:43 ` graeme.gregory at linaro.org
2014-07-24 13:00 ` [PATCH 07/19] ARM64 / ACPI: Parse MADT to map logical cpu to MPIDR and get cpu_possible/present_map Hanjun Guo
2014-07-24 23:06 ` Naresh Bhat
2014-07-25 11:11 ` Hanjun Guo
2014-07-30 18:20 ` Sudeep Holla
2014-07-31 8:14 ` Hanjun Guo
2014-08-20 15:14 ` Grant Likely
2014-07-24 13:00 ` [PATCH 08/19] ACPI / table: Print GIC information when MADT is parsed Hanjun Guo
2014-07-30 18:21 ` Sudeep Holla
2014-07-31 8:15 ` Hanjun Guo
2014-07-24 13:00 ` [PATCH 09/19] ARM64 / ACPI: Move the initialization of cpu_logical_map(0) before acpi_boot_init() Hanjun Guo
2014-07-24 15:21 ` Mark Rutland
2014-07-25 10:39 ` Hanjun Guo
2014-07-25 12:18 ` Mark Rutland
2014-07-24 13:00 ` [PATCH 10/19] ARM64 / ACPI: Get the enable method for SMP initialization in ACPI way Hanjun Guo
2014-07-24 15:47 ` Mark Rutland
2014-07-25 10:51 ` Hanjun Guo
2014-07-25 12:24 ` Mark Rutland
2014-07-29 8:12 ` Hanjun Guo
2014-07-31 6:54 ` Olof Johansson
2014-07-31 10:57 ` Hanjun Guo
2014-08-04 9:56 ` Hanjun Guo
2014-07-31 18:52 ` Geoff Levand
2014-08-01 6:49 ` Hanjun Guo
2014-07-24 13:00 ` [PATCH 11/19] ACPI / processor: Make it possible to get CPU hardware ID via GICC Hanjun Guo
2014-07-24 13:00 ` [PATCH 12/19] ARM64 / ACPI: Introduce ACPI_IRQ_MODEL_GIC and register device's gsi Hanjun Guo
2014-07-24 13:00 ` [PATCH 13/19] ACPI / table: Add new function to get table entries Hanjun Guo
2014-07-24 13:00 ` [PATCH 14/19] ARM64 / ACPI: Add GICv2 specific ACPI boot support Hanjun Guo
2014-07-24 13:00 ` [PATCH 15/19] ARM64 / ACPI: Parse GTDT to initialize arch timer Hanjun Guo
2014-07-24 13:00 ` [PATCH 16/19] ARM64 / ACPI: Select ACPI_REDUCED_HARDWARE_ONLY if ACPI is enabled on ARM64 Hanjun Guo
2014-07-24 13:00 ` [PATCH 17/19] ARM64 / ACPI: If we chose to boot from acpi then disable FDT Hanjun Guo
2014-07-24 13:00 ` [PATCH 18/19] ARM64 / ACPI: Enable ARM64 in Kconfig Hanjun Guo
2014-07-24 13:00 ` [PATCH 19/19] Documentation: ACPI for ARM64 Hanjun Guo
2014-07-24 20:42 ` Randy Dunlap
2014-07-25 10:55 ` Hanjun Guo
[not found] ` <CAFoFrHaWWxRPRYM5+bWj0tGnz05SokqwVGejUCUi+U-KChFBdQ@mail.gmail.com>
2014-07-24 21:19 ` Randy Dunlap
2014-07-29 10:07 ` Christoffer Dall
2014-07-27 2:34 ` Olof Johansson
2014-07-28 8:42 ` Graeme Gregory
2014-07-28 16:23 ` Olof Johansson
2014-07-28 17:44 ` Mark Brown
2014-07-28 9:07 ` Arnd Bergmann
2014-07-28 9:23 ` Graeme Gregory
2014-07-28 10:46 ` Arnd Bergmann
2014-07-28 14:20 ` Andre Przywara
2014-07-28 15:23 ` Arnd Bergmann
2014-07-28 16:14 ` Andre Przywara
2014-07-29 9:17 ` Graeme Gregory
2014-07-29 10:07 ` Arnd Bergmann
2014-07-28 10:12 ` Mark Rutland
2014-07-28 16:33 ` Olof Johansson
2014-07-28 18:37 ` Mark Rutland
2014-07-28 18:44 ` Olof Johansson
2014-07-28 16:27 ` Olof Johansson
2014-07-28 17:00 ` Mark Rutland
2014-07-28 18:27 ` Olof Johansson
2014-08-12 18:23 ` Catalin Marinas
2014-08-13 23:41 ` Rafael J. Wysocki
2014-08-14 3:21 ` Hanjun Guo
2014-08-14 10:27 ` Catalin Marinas
2014-08-14 20:53 ` Arnd Bergmann
2014-08-15 1:02 ` Olof Johansson
2014-08-15 19:49 ` Arnd Bergmann
2014-08-15 23:19 ` Mark Brown
2014-08-16 12:51 ` graeme.gregory at linaro.org
2014-08-15 9:09 ` Hanjun Guo [this message]
2014-08-15 10:01 ` Catalin Marinas
2014-08-18 9:29 ` Hanjun Guo
2014-08-18 12:49 ` Mark Rutland
2014-08-20 22:17 ` Olof Johansson
2014-08-21 4:00 ` Hanjun Guo
2014-07-29 9:01 ` Hanjun Guo
2014-07-28 10:06 ` Mark Rutland
2014-07-28 16:44 ` Olof Johansson
2014-07-28 17:36 ` Mark Rutland
2014-07-28 18:34 ` Olof Johansson
2014-07-29 10:29 ` Christoffer Dall
2014-07-29 10:41 ` Arnd Bergmann
2014-07-29 10:55 ` Mark Rutland
2014-07-29 11:28 ` Mark Rutland
2014-07-29 12:37 ` Christoffer Dall
2014-07-29 12:52 ` Arnd Bergmann
2014-07-29 13:08 ` Mark Rutland
2014-07-29 13:31 ` Christoffer Dall
2014-07-29 14:04 ` Mark Rutland
2014-07-29 14:41 ` Arnd Bergmann
2014-07-29 15:01 ` Christoffer Dall
2014-07-30 6:47 ` Hanjun Guo
2014-07-30 7:14 ` Christoffer Dall
2014-07-30 9:36 ` Hanjun Guo
2014-07-29 13:33 ` Christoffer Dall
2014-07-29 7:58 ` Hanjun Guo
2014-07-29 10:30 ` Christoffer Dall
2014-08-15 22:43 ` Len Brown
2014-08-16 12:45 ` Graeme Gregory
2014-08-20 16:42 ` Grant Likely
2014-07-25 0:46 ` [PATCH 00/19] Introduce ACPI for ARM64 based on ACPI 5.1 Hanjun Guo
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