diff options
| author | James Morse <[email protected]> | 2022-09-09 16:59:36 +0000 |
|---|---|---|
| committer | Catalin Marinas <[email protected]> | 2022-09-16 14:16:34 +0000 |
| commit | 237405ebef580a7352a52129b2465c117145eafa (patch) | |
| tree | 230ce084281a4d3c964cbb2e0675ff88be865582 /lib/overflow_kunit.c | |
| parent | Linux 6.0-rc3 (diff) | |
| download | kernel-237405ebef580a7352a52129b2465c117145eafa.tar.gz kernel-237405ebef580a7352a52129b2465c117145eafa.zip | |
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 <[email protected]>
Reviewed-by: Suzuki K Poulose <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Catalin Marinas <[email protected]>
Diffstat (limited to 'lib/overflow_kunit.c')
0 files changed, 0 insertions, 0 deletions