From: Suzuki K Poulose <suzuki.poulose@arm.com>
Date: Wed, 3 Feb 2021 23:00:57 +0000
Subject: arm64: Extend workaround for erratum 1024718 to all versions of
Cortex-A55
Git-commit: c0b15c25d25171db4b70cc0b7dbc1130ee94017d
Patch-mainline: v5.12-rc1
References: git-fixes
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
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>
Acked-by: Ivan T. Ivanov <iivanov@suse.de>
---
arch/arm64/Kconfig | 2 +-
arch/arm64/kernel/cpufeature.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -494,7 +494,7 @@ 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
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1131,7 +1131,7 @@ 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
{},
};