[PATCH V3 RESEND 4/7] arm64: errata: Add detection for TRBE trace data corruption
From: Anshuman Khandual <hidden>
Date: 2022-01-25 14:29:30
Also in:
linux-doc, lkml
Subsystem:
arm64 port (aarch64 architecture), documentation, the rest · Maintainers:
Catalin Marinas, Will Deacon, Jonathan Corbet, Linus Torvalds
TRBE implementations affected by Arm erratum #1902691 might corrupt trace data or deadlock, when it's being written into the memory. So effectively TRBE is broken and hence cannot be used to capture trace data. This adds a new errata ARM64_ERRATUM_1902691 in arm64 errata framework. Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Suzuki Poulose <suzuki.poulose@arm.com> Cc: coresight@lists.linaro.org Cc: linux-doc@vger.kernel.org Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Anshuman Khandual <redacted> --- Documentation/arm64/silicon-errata.rst | 2 ++ arch/arm64/Kconfig | 18 ++++++++++++++++++ arch/arm64/kernel/cpu_errata.c | 9 +++++++++ arch/arm64/tools/cpucaps | 1 + 4 files changed, 30 insertions(+)
diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst
index e0ef3e9a4b8b..50018f60c4d4 100644
--- a/Documentation/arm64/silicon-errata.rst
+++ b/Documentation/arm64/silicon-errata.rst@@ -56,6 +56,8 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A510 | #2038923 | ARM64_ERRATUM_2038923 | +----------------+-----------------+-----------------+-----------------------------+ +| ARM | Cortex-A510 | #1902691 | ARM64_ERRATUM_1902691 | ++----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A53 | #826319 | ARM64_ERRATUM_826319 | +----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A53 | #827319 | ARM64_ERRATUM_827319 |
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index fecf2b09e870..9c3cf3875785 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig@@ -819,6 +819,24 @@ config ARM64_ERRATUM_2038923 If unsure, say Y. +config ARM64_ERRATUM_1902691 + bool "Cortex-A510: 1902691: workaround TRBE trace corruption" + depends on COMPILE_TEST # Until the CoreSight TRBE driver changes are in + default y + help + This option adds the workaround for ARM Cortex-A510 erratum 1902691. + + Affected Cortex-A510 core might cause trace data corruption, when being written + into the memory. Effectively TRBE is broken and hence cannot be used to capture + trace data. + + Work around this problem in the driver by just preventing TRBE initialization on + affected cpus. The firmware must have disabled the access to TRBE for the kernel + on such implementations. This will cover the kernel for any firmware that doesn't + do this already. + + If unsure, say Y. + config CAVIUM_ERRATUM_22375 bool "Cavium erratum 22375, 24313" default y
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 60b0c1f1d912..a3336dfb5a8a 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c@@ -615,6 +615,15 @@ const struct arm64_cpu_capabilities arm64_errata[] = { /* Cortex-A510 r0p0 - r0p2 */ ERRATA_MIDR_REV_RANGE(MIDR_CORTEX_A510, 0, 0, 2) }, +#endif +#ifdef CONFIG_ARM64_ERRATUM_1902691 + { + .desc = "ARM erratum 1902691", + .capability = ARM64_WORKAROUND_1902691, + + /* Cortex-A510 r0p0 - r0p1 */ + ERRATA_MIDR_REV_RANGE(MIDR_CORTEX_A510, 0, 0, 1) + }, #endif { }
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 45a06d36d080..e7719e8f18de 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps@@ -57,6 +57,7 @@ WORKAROUND_1508412 WORKAROUND_1542419 WORKAROUND_2064142 WORKAROUND_2038923 +WORKAROUND_1902691 WORKAROUND_TRBE_OVERWRITE_FILL_MODE WORKAROUND_TSB_FLUSH_FAILURE WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
--
2.25.1
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