arm64: cpufeature: Expose CPUID registers by emulation

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This patch adds the hook for emulating MRS instruction to
export the 'user visible' value of supported system registers.
We emulate only the following id space for system registers:

 Op0=3, Op1=0, CRn=0, CRm=[0, 4-7]

The rest will fall back to SIGILL. This capability is also
advertised via a new HWCAP_CPUID.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
[will: add missing static keyword to enable_mrs_emulation]
Signed-off-by: Will Deacon <will.deacon@arm.com>

...

This commit is contained in:

Suzuki K Poulose 2017-01-09 17:28:31 +00:00 • committed by Will Deacon

parent fe4fbdbcdd

commit 77c97b4ee2

4 changed files with 107 additions and 0 deletions

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4

arch/arm64/include/asm/sysreg.h

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1

arch/arm64/include/uapi/asm/hwcap.h

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101

arch/arm64/kernel/cpufeature.c

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1

arch/arm64/kernel/cpuinfo.c

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