arm64: Extend workaround for erratum 1024718 to all versions of Cortex-A55

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
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a6b5b7ef40aea08f036e58d2684f87f378773644..afe4bc55d4eba08679f5d099781f85324bbd7a93 100644 (file)
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -520,7 +520,7 @@ 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 65a522fbd87431bdf19c265b551f8ccba15e89fb..7da9a7cee4cef54c36b01a6785ea465ea61001ad 100644 (file)
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1457,7 +1457,7 @@ 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),
                /* Kryo4xx Silver (rdpe => r1p0) */
                MIDR_REV(MIDR_QCOM_KRYO_4XX_SILVER, 0xd, 0xe),
 #endif