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| author |  Mark Brown <broonie@kernel.org>
| 2022-07-07 11:36:30 +0100 |
|---|---|---|
| committer |  Will Deacon <will@kernel.org>
| 2022-07-20 11:18:11 +0100 |
| commit | d3e4a9d30804a78387bfcb383371209417e05c9a (patch) | |
| tree | 89a84ff4aac76af570967b559a25fdb87de6d7bd /arch/arm64/include/uapi | |
| parent | arm64: trap implementation defined functionality in userspace (diff) | |
| download | linux-d3e4a9d30804a78387bfcb383371209417e05c9a.tar.gz linux-d3e4a9d30804a78387bfcb383371209417e05c9a.tar.bz2 linux-d3e4a9d30804a78387bfcb383371209417e05c9a.zip | |
arm64/hwcap: Document allocation of upper bits of AT_HWCAP
The top two bits of AT_HWCAP are reserved for use by glibc and the rest of
the top 32 bits are being kept unallocated for potential use by glibc.
Document this in the header.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Link: https://lore.kernel.org/r/20220707103632.12745-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'arch/arm64/include/uapi')
| -rw-r--r-- | arch/arm64/include/uapi/asm/hwcap.h | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/arch/arm64/include/uapi/asm/hwcap.h b/arch/arm64/include/uapi/asm/hwcap.h index 4bb2cc8ac446..fd7577cf8e77 100644 --- a/arch/arm64/include/uapi/asm/hwcap.h +++ b/arch/arm64/include/uapi/asm/hwcap.h @@ -19,6 +19,9 @@ /* * HWCAP flags - for AT_HWCAP + * + * Bits 62 and 63 are reserved for use by libc. + * Bits 32-61 are unallocated for potential use by libc. */ #define HWCAP_FP (1 << 0) #define HWCAP_ASIMD (1 << 1) |