This is a note to let you know that I've just added the patch titled
arm64: errata: Add detection for TRBE trace data corruption
to the 5.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
arm64-errata-add-detection-for-trbe-trace-data-corru.patch
and it can be found in the queue-5.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 1cddfe24145084ac23c16d1db5e60717a7244a08
Author: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Date: Tue Jan 25 19:50:34 2022 +0530
arm64: errata: Add detection for TRBE trace data corruption
[ Upstream commit 708e8af4924ec2fdd5b81fe09192c6bac2f86935 ]
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@xxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Cc: Suzuki Poulose <suzuki.poulose@xxxxxxx>
Cc: coresight@xxxxxxxxxxxxxxxx
Cc: linux-doc@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Reviewed-by: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Acked-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
Link: https://lore.kernel.org/r/1643120437-14352-5-git-send-email-anshuman.khandual@xxxxxxx
Signed-off-by: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst
index d5c6befc44eb8..1b0e53ececda9 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 2b75e8a9bf88c..7d710589e1818 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 a64bf132c6336..066098198c248 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -617,6 +617,15 @@ 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 45a06d36d0807..e7719e8f18def 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
