| Subject | Re: [PATCH v3 24/24] arm64: cpuinfo: Expose MIDR_EL1 and REVIDR_EL1 to sysfs | From | "Suzuki K. Poulose" <> | Date | Wed, 14 Oct 2015 10:03:51 +0100 |
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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
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