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| author | James Morse <james.morse@arm.com> | 2022-09-09 19:59:36 +0300 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2022-09-16 17:16:34 +0300 |
| commit | 237405ebef580a7352a52129b2465c117145eafa (patch) | |
| tree | 230ce084281a4d3c964cbb2e0675ff88be865582 /tools/perf/scripts/python/export-to-postgresql.py | |
| parent | b90cb1053190353cc30f0fef0ef1f378ccc063c5 (diff) | |
| download | linux-237405ebef580a7352a52129b2465c117145eafa.tar.xz | |
arm64: cpufeature: Force HWCAP to be based on the sysreg visible to user-space
arm64 advertises hardware features to user-space via HWCAPs, and by
emulating access to the CPUs id registers. The cpufeature code has a
sanitised system-wide view of an id register, and a sanitised user-space
view of an id register, where some features use their 'safe' value
instead of the hardware value.
It is currently possible for a HWCAP to be advertised where the user-space
view of the id register does not show the feature as supported.
Erratum workaround need to remove both the HWCAP, and the feature from
the user-space view of the id register. This involves duplicating the
code, and spreading it over cpufeature.c and cpu_errata.c.
Make the HWCAP code use the user-space view of id registers. This ensures
the values never diverge, and allows erratum workaround to remove HWCAP
by modifying the user-space view of the id register.
Signed-off-by: James Morse <james.morse@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20220909165938.3931307-2-james.morse@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'tools/perf/scripts/python/export-to-postgresql.py')
0 files changed, 0 insertions, 0 deletions