[PATCH V2 2/7] arm64: errata: Add detection for TRBE ignored system register writes
From: Anshuman Khandual <hidden>
Date: 2022-01-07 01:10:26
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 #2064142 might fail to write into certain system registers after the TRBE has been disabled. Under some conditions after TRBE has been disabled, writes into certain TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1 and TRBTRG_EL1 will be ignored and not be effected. This adds a new errata ARM64_ERRATUM_2064142 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 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 5342e895fb60..c9b30e6c2b6c 100644
--- a/Documentation/arm64/silicon-errata.rst
+++ b/Documentation/arm64/silicon-errata.rst@@ -52,6 +52,8 @@ stable kernels. | Allwinner | A64/R18 | UNKNOWN1 | SUN50I_ERRATUM_UNKNOWN1 | +----------------+-----------------+-----------------+-----------------------------+ +----------------+-----------------+-----------------+-----------------------------+ +| ARM | Cortex-A510 | #2064142 | ARM64_ERRATUM_2064142 | ++----------------+-----------------+-----------------+-----------------------------+ | 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 c4207cf9bb17..e27ccfe9fa9c 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig@@ -778,6 +778,24 @@ config ARM64_ERRATUM_2224489 If unsure, say Y. +config ARM64_ERRATUM_2064142 + bool "Cortex-A510: 2064142: workaround TRBE register writes while disabled" + 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 2064142. + + Affected Cortex-A510 core might fail to write into system registers after the + TRBE has been disabled. Under some conditions after the TRBE has been disabled + writes into TRBE registers TRBLIMITR_EL1, TRBPTR_EL1, TRBBASER_EL1, TRBSR_EL1, + and TRBTRG_EL1 will be ignored and will not be effected. + + Work around this in the driver by executing TSB CSYNC and DSB after collection + is stopped and before performing a system register write to one of the affected + registers. + + 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 9e1c1aef9ebd..cbb7d5a9aee7 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c@@ -597,6 +597,15 @@ const struct arm64_cpu_capabilities arm64_errata[] = { .type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE, CAP_MIDR_RANGE_LIST(trbe_write_out_of_range_cpus), }, +#endif +#ifdef CONFIG_ARM64_ERRATUM_2064142 + { + .desc = "ARM erratum 2064142", + .capability = ARM64_WORKAROUND_2064142, + + /* Cortex-A510 r0p0 - r0p2 */ + ERRATA_MIDR_REV_RANGE(MIDR_CORTEX_A510, 0, 0, 2) + }, #endif { }
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 870c39537dd0..fca3cb329e1d 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps@@ -55,6 +55,7 @@ WORKAROUND_1418040 WORKAROUND_1463225 WORKAROUND_1508412 WORKAROUND_1542419 +WORKAROUND_2064142 WORKAROUND_TRBE_OVERWRITE_FILL_MODE WORKAROUND_TSB_FLUSH_FAILURE WORKAROUND_TRBE_WRITE_OUT_OF_RANGE
--
2.25.1
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