5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mark Rutland mark.rutland@arm.com
[ Upstream commit 75b3c43eab594bfbd8184ec8ee1a6b820950819a ]
A number of Arm Ltd CPUs suffer from errata whereby an MSR to the SSBS special-purpose register does not affect subsequent speculative instructions, permitting speculative store bypassing for a window of time.
We worked around this for Cortex-X4 and Neoverse-V3, in commit:
7187bb7d0b5c7dfa ("arm64: errata: Add workaround for Arm errata 3194386 and 3312417")
... as per their Software Developer Errata Notice (SDEN) documents:
* Cortex-X4 SDEN v8.0, erratum 3194386: https://developer.arm.com/documentation/SDEN-2432808/0800/
* Neoverse-V3 SDEN v6.0, erratum 3312417: https://developer.arm.com/documentation/SDEN-2891958/0600/
Since then, similar errata have been published for a number of other Arm Ltd CPUs, for which the mitigation is the same. This is described in their respective SDEN documents:
* Cortex-A710 SDEN v19.0, errataum 3324338 https://developer.arm.com/documentation/SDEN-1775101/1900/?lang=en
* Cortex-A720 SDEN v11.0, erratum 3456091 https://developer.arm.com/documentation/SDEN-2439421/1100/?lang=en
* Cortex-X2 SDEN v19.0, erratum 3324338 https://developer.arm.com/documentation/SDEN-1775100/1900/?lang=en
* Cortex-X3 SDEN v14.0, erratum 3324335 https://developer.arm.com/documentation/SDEN-2055130/1400/?lang=en
* Cortex-X925 SDEN v8.0, erratum 3324334 https://developer.arm.com/documentation/109108/800/?lang=en
* Neoverse-N2 SDEN v17.0, erratum 3324339 https://developer.arm.com/documentation/SDEN-1982442/1700/?lang=en
* Neoverse-V2 SDEN v9.0, erratum 3324336 https://developer.arm.com/documentation/SDEN-2332927/900/?lang=en
Note that due to shared design lineage, some CPUs share the same erratum number.
Add these to the existing mitigation under CONFIG_ARM64_ERRATUM_3194386. As listing all of the erratum IDs in the runtime description would be unwieldy, this is reduced to:
"SSBS not fully self-synchronizing"
... matching the description of the errata in all of the SDENs.
Signed-off-by: Mark Rutland mark.rutland@arm.com Cc: James Morse james.morse@arm.com Cc: Will Deacon will@kernel.org Link: https://lore.kernel.org/r/20240603111812.1514101-6-mark.rutland@arm.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com [ Mark: fix conflicts and renames ] Signed-off-by: Mark Rutland mark.rutland@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- Documentation/arm64/silicon-errata.rst | 14 ++++++++++++++ arch/arm64/Kconfig | 9 ++++++++- arch/arm64/kernel/cpu_errata.c | 9 ++++++++- 3 files changed, 30 insertions(+), 2 deletions(-)
diff --git a/Documentation/arm64/silicon-errata.rst b/Documentation/arm64/silicon-errata.rst index 13d77af92edf7..1740c0dfd5503 100644 --- a/Documentation/arm64/silicon-errata.rst +++ b/Documentation/arm64/silicon-errata.rst @@ -108,8 +108,18 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-A710 | #2224489 | ARM64_ERRATUM_2224489 | +----------------+-----------------+-----------------+-----------------------------+ +| ARM | Cortex-A710 | #3324338 | ARM64_ERRATUM_3194386 | ++----------------+-----------------+-----------------+-----------------------------+ +| ARM | Cortex-A720 | #3456091 | ARM64_ERRATUM_3194386 | ++----------------+-----------------+-----------------+-----------------------------+ +| ARM | Cortex-X2 | #3324338 | ARM64_ERRATUM_3194386 | ++----------------+-----------------+-----------------+-----------------------------+ +| ARM | Cortex-X3 | #3324335 | ARM64_ERRATUM_3194386 | ++----------------+-----------------+-----------------+-----------------------------+ | ARM | Cortex-X4 | #3194386 | ARM64_ERRATUM_3194386 | +----------------+-----------------+-----------------+-----------------------------+ +| ARM | Cortex-X925 | #3324334 | ARM64_ERRATUM_3194386 | ++----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-N1 | #1188873,1418040| ARM64_ERRATUM_1418040 | +----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-N1 | #1349291 | N/A | @@ -122,6 +132,10 @@ stable kernels. +----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-N2 | #2253138 | ARM64_ERRATUM_2253138 | +----------------+-----------------+-----------------+-----------------------------+ +| ARM | Neoverse-N2 | #3324339 | ARM64_ERRATUM_3194386 | ++----------------+-----------------+-----------------+-----------------------------+ +| ARM | Neoverse-V2 | #3324336 | ARM64_ERRATUM_3194386 | ++----------------+-----------------+-----------------+-----------------------------+ | ARM | Neoverse-V3 | #3312417 | ARM64_ERRATUM_3194386 | +----------------+-----------------+-----------------+-----------------------------+ | ARM | MMU-500 | #841119,826419 | N/A | diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 623b30c21c00d..91a956605925b 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -849,12 +849,19 @@ config ARM64_ERRATUM_2224489 If unsure, say Y.
config ARM64_ERRATUM_3194386 - bool "Cortex-X4/Neoverse-V3: workaround for MSR SSBS not self-synchronizing" + bool "Cortex-{A720,X4,X925}/Neoverse-V3: workaround for MSR SSBS not self-synchronizing" default y help This option adds the workaround for the following errata:
+ * ARM Cortex-A710 erratam 3324338 + * ARM Cortex-A720 erratum 3456091 + * ARM Cortex-X2 erratum 3324338 + * ARM Cortex-X3 erratum 3324335 * ARM Cortex-X4 erratum 3194386 + * ARM Cortex-X925 erratum 3324334 + * ARM Neoverse N2 erratum 3324339 + * ARM Neoverse V2 erratum 3324336 * ARM Neoverse-V3 erratum 3312417
On affected cores "MSR SSBS, #0" instructions may not affect diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c index 0fe2d65e646fe..f360ec1619bd5 100644 --- a/arch/arm64/kernel/cpu_errata.c +++ b/arch/arm64/kernel/cpu_errata.c @@ -404,8 +404,15 @@ static struct midr_range trbe_write_out_of_range_cpus[] = {
#ifdef CONFIG_ARM64_ERRATUM_3194386 static const struct midr_range erratum_spec_ssbs_list[] = { + MIDR_ALL_VERSIONS(MIDR_CORTEX_A710), + MIDR_ALL_VERSIONS(MIDR_CORTEX_A720), + MIDR_ALL_VERSIONS(MIDR_CORTEX_X2), + MIDR_ALL_VERSIONS(MIDR_CORTEX_X3), MIDR_ALL_VERSIONS(MIDR_CORTEX_X4), + MIDR_ALL_VERSIONS(MIDR_CORTEX_X925), + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N2), MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V3), + MIDR_ALL_VERSIONS(MIDR_NEOVERSE_V2), {} }; #endif @@ -659,7 +666,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = { #endif #ifdef CONFIG_ARM64_ERRATUM_3194386 { - .desc = "ARM errata 3194386, 3312417", + .desc = "SSBS not fully self-synchronizing", .capability = ARM64_WORKAROUND_SPECULATIVE_SSBS, ERRATA_MIDR_RANGE_LIST(erratum_spec_ssbs_list), },