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arm64: errata: Expand speculative SSBS workaround

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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:

  7187bb7d0b ("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>
This commit is contained in:
Mark Rutland 2024-06-03 12:18:12 +01:00 committed by Catalin Marinas
parent ec76876660
commit 75b3c43eab
3 changed files with 30 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

14
Documentation/arch/arm64/silicon-errata.rst
View File

@ -132,16 +132,26 @@ stable kernels.
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A710 | #2224489 | ARM64_ERRATUM_2224489 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A710 | #3324338 | ARM64_ERRATUM_3194386 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A715 | #2645198 | ARM64_ERRATUM_2645198 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-A720 | #3456091 | ARM64_ERRATUM_3194386 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-X1 | #1502854 | N/A |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-X2 | #2119858 | ARM64_ERRATUM_2119858 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Cortex-X2 | #2224489 | ARM64_ERRATUM_2224489 |
+----------------+-----------------+-----------------+-----------------------------+
| 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 |
@ -156,8 +166,12 @@ stable kernels.
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-N2 | #2253138 | ARM64_ERRATUM_2253138 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-N2 | #3324339 | ARM64_ERRATUM_3194386 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-V1 | #1619801 | N/A |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-V2 | #3324336 | ARM64_ERRATUM_3194386 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-V3 | #3312417 | ARM64_ERRATUM_3194386 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | MMU-500 | #841119,826419 | N/A |

9
arch/arm64/Kconfig
View File

@ -1068,12 +1068,19 @@ config ARM64_ERRATUM_3117295
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

9
arch/arm64/kernel/cpu_errata.c
View File

@ -434,8 +434,15 @@ static const struct midr_range erratum_spec_unpriv_load_list[] = {
#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
@ -739,7 +746,7 @@ 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),
},