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| author | Steve Capper <steve.capper@linaro.org> | 2016-07-08 16:01:13 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2016-07-12 16:09:37 +0100 |
| commit | f8d9f924526ad3c983569437f60e3833d6c55578 (patch) | |
| tree | 0f8222aa38a71ac52a9a43367211f54a6d854011 /Documentation/ABI | |
| parent | 49eea433b326a0ac5c7c941a011b2c65990bd19b (diff) | |
| download | linux-rpi-f8d9f924526ad3c983569437f60e3833d6c55578.tar.gz linux-rpi-f8d9f924526ad3c983569437f60e3833d6c55578.tar.bz2 linux-rpi-f8d9f924526ad3c983569437f60e3833d6c55578.zip | |
arm64: cpuinfo: Expose MIDR_EL1 and REVIDR_EL1 to sysfs
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 code generation.
This patch exposes these registers through sysfs:
/sys/devices/system/cpu/cpu$ID/regs/identification/midr_el1
/sys/devices/system/cpu/cpu$ID/regs/identification/revidr_el1
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.
Cc: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Steve Capper <steve.capper@linaro.org>
[suzuki.poulose@arm.com: ABI documentation updates, hotplug notifiers, kobject changes]
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-system-cpu | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 16501334b99f..498741737055 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -340,3 +340,13 @@ Description: POWERNV CPUFreq driver's frequency throttle stats directory and 'policyX/throttle_stats' directory and all the attributes are same as the /sys/devices/system/cpu/cpuX/cpufreq/throttle_stats directory and attributes which give the frequency throttle information of the chip. + +What: /sys/devices/system/cpu/cpuX/regs/ + /sys/devices/system/cpu/cpuX/regs/identification/ + /sys/devices/system/cpu/cpuX/regs/identification/midr_el1 + /sys/devices/system/cpu/cpuX/regs/identification/revidr_el1 +Date: June 2016 +Contact: Linux ARM Kernel Mailing list <linux-arm-kernel@lists.infradead.org> +Description: AArch64 CPU registers + 'identification' directory exposes the CPU ID registers for + identifying model and revision of the CPU. |