| Message ID | 20210301125815.3047065-1-suzuki.poulose@arm.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] arm64: Extend workaround for erratum 1024718 to all versions of Cortex-A55 | expand |
On Mon, Mar 01, 2021 at 12:58:15PM +0000, Suzuki K Poulose wrote: > commit c0b15c25d25171db4b70cc0b7dbc1130ee94017d upstream > > The erratum 1024718 affects Cortex-A55 r0p0 to r2p0. However > we apply the work around for r0p0 - r1p0. Unfortunately this > won't be fixed for the future revisions for the CPU. Thus > extend the work around for all versions of A55, to cover > for r2p0 and any future revisions. > > Cc: stable@vger.kernel.org # v5.4- > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will@kernel.org> > Cc: James Morse <james.morse@arm.com> > Cc: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > Link: https://lore.kernel.org/r/20210203230057.3961239-1-suzuki.poulose@arm.com > [will: Update Kconfig help text] > Signed-off-by: Will Deacon <will@kernel.org> > Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> > --- > Changes in v2: > - Match the Kconfig text to the original commit > "versions" => "revisions" > > arch/arm64/Kconfig | 2 +- > arch/arm64/kernel/cpufeature.c | 2 +- > 2 files changed, 2 insertions(+), 2 deletions(-) Applied to 5.4.y and 4.19.y, if it needs to go anywhere older, please provide working backports. thanks, greg k-h
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index a0bc9bbb92f3..9c8ea5939865 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -489,7 +489,7 @@ config ARM64_ERRATUM_1024718 help This option adds a workaround for ARM Cortex-A55 Erratum 1024718. - Affected Cortex-A55 cores (r0p0, r0p1, r1p0) could cause incorrect + Affected Cortex-A55 cores (all revisions) could cause incorrect update of the hardware dirty bit when the DBM/AP bits are updated without a break-before-make. The workaround is to disable the usage of hardware DBM locally on the affected cores. CPUs not affected by diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index f2ec84540414..79caab15ccbf 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -1092,7 +1092,7 @@ static bool cpu_has_broken_dbm(void) /* List of CPUs which have broken DBM support. */ static const struct midr_range cpus[] = { #ifdef CONFIG_ARM64_ERRATUM_1024718 - MIDR_RANGE(MIDR_CORTEX_A55, 0, 0, 1, 0), // A55 r0p0 -r1p0 + MIDR_ALL_VERSIONS(MIDR_CORTEX_A55), #endif {}, };