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From: "Suzuki K. Poulose" <Suzuki.Poulose@arm.com>
To: linux-arm-kernel@lists.infradead.org
Cc: catalin.marinas@arm.com, will.deacon@arm.com,
	mark.rutland@arm.com, dave.martin@arm.com,
	Vladimir.Murzin@arm.com, steve.capper@linaro.org,
	linux-kernel@vger.kernel.org, ard.biesheuvel@linaro.org,
	james.morse@arm.com, marc.zyngier@arm.com,
	christoffer.dall@linaro.org, andre.przywara@arm.com,
	edward.nevill@linaro.org, aph@redhat.com, ryan.arnold@linaro.org
Subject: Re: [PATCH v3 24/24] arm64: cpuinfo: Expose MIDR_EL1 and REVIDR_EL1 to sysfs
Date: Wed, 14 Oct 2015 10:03:51 +0100	[thread overview]
Message-ID: <561E1A77.1060902@arm.com> (raw)
In-Reply-To: <1444756952-31145-25-git-send-email-suzuki.poulose@arm.com>

On 13/10/15 18:22, Suzuki K. Poulose wrote:
> From: Steve Capper <steve.capper@linaro.org>
>
> It can be useful for JIT software to be aware of MIDR_EL1 and
> REVIDR_EL1 to ascertain the presence of any core errata that could
> affect codegen.
>
> This patch exposes these registers through sysfs:
>
> /sys/devices/system/cpu/cpu$ID/identification/midr
> /sys/devices/system/cpu/cpu$ID/identification/revidr
>
> where $ID is the cpu number. For big.LITTLE systems, one can have a
> mixture of cores (e.g. Cortex A53 and Cortex A57), thus all CPUs need
> to be enumerated.
>
> If the kernel does not have valid information to populate these entries
> with, an empty string is returned to userspace.
>

For the record:

> Signed-off-by: Steve Capper <steve.capper@linaro.org>
  [ Added error code for cpus !present in show_xxx_name ]
> Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>

Suzuki


  reply	other threads:[~2015-10-14  9:03 UTC|newest]

Thread overview: 38+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-10-13 17:22 [PATCH v3 00/24] arm64: Consolidate CPU feature handling Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 01/24] arm64: Make the CPU information more clear Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 02/24] arm64: Delay ELF HWCAP initialisation until all CPUs are up Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 03/24] arm64: Delay cpuinfo_store_boot_cpu Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 04/24] arm64: Move cpu feature detection code Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 05/24] arm64: Move mixed endian support detection Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 06/24] arm64: Move /proc/cpuinfo handling code Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 07/24] arm64: Define helper for sys_reg id manipulation Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 08/24] arm64: Handle width of a cpuid feature Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 09/24] arm64: Keep track of CPU feature registers Suzuki K. Poulose
2015-10-15 10:36   ` Catalin Marinas
2015-10-15 10:45     ` Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 10/24] arm64: Consolidate CPU Sanity check to CPU Feature infrastructure Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 11/24] arm64: Read system wide CPUID value Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 12/24] arm64: Cleanup mixed endian support detection Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 13/24] arm64: Populate cpuinfo after notify_cpu_starting Suzuki K. Poulose
2015-10-15 10:54   ` Catalin Marinas
2015-10-15 13:23     ` Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 14/24] arm64: Delay cpu feature capability checks Suzuki K. Poulose
2015-10-17 22:56   ` kbuild test robot
2015-10-19  9:41     ` Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 15/24] arm64: Make use of system wide " Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 16/24] arm64: Cleanup HWCAP handling Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 17/24] arm64: Move FP/ASIMD hwcap handling to common code Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 18/24] arm64/debug: Make use of the system wide safe value Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 19/24] arm64/kvm: Make use of the system wide safe values Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 20/24] arm64: Documentation - Expose CPU feature registers Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 21/24] arm64: Add helper to decode register from instruction Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 22/24] arm64: cpufeature: Track the user visible fields Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 23/24] arm64: Expose feature registers by emulating MRS Suzuki K. Poulose
2015-10-13 17:22 ` [PATCH v3 24/24] arm64: cpuinfo: Expose MIDR_EL1 and REVIDR_EL1 to sysfs Suzuki K. Poulose
2015-10-14  9:03   ` Suzuki K. Poulose [this message]
2015-10-16 15:13 ` [PATCH v3 00/24] arm64: Consolidate CPU feature handling Dave Martin
2015-10-16 15:32   ` Suzuki K. Poulose
2015-10-16 15:42     ` Dave Martin
2015-10-25  8:06 ` Siddhesh Poyarekar
2015-10-27 18:09   ` Suzuki K. Poulose
2015-10-28  8:53     ` Siddhesh Poyarekar

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