[PATCH v2] arm64: errata: Enable the AC03_CPU_38 workaround for ampere1a

[PATCH v2] arm64: errata: Enable the AC03_CPU_38 workaround for ampere1a

[D Scott Phillips]

The ampere1a cpu is affected by erratum AC04_CPU_10 which is the same
bug as AC03_CPU_38. Add ampere1a to the AC03_CPU_38 workaround midr list.

Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com>
---
Changes since v1:
 - Link: https://lore.kernel.org/lkml/20240826215933.1263453-1-scott@os.amperecomputing.com/
 - Used ERRATA_MIDR_RANGE_LIST so both midrs are properly covered. (Oliver)

 Documentation/arch/arm64/silicon-errata.rst |  2 ++
 arch/arm64/Kconfig                          |  2 +-
 arch/arm64/include/asm/cputype.h            |  2 ++
 arch/arm64/kernel/cpu_errata.c              | 10 +++++++++-
 4 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst
index 50327c05be8d1..39c52385f11fb 100644
--- a/Documentation/arch/arm64/silicon-errata.rst
+++ b/Documentation/arch/arm64/silicon-errata.rst
@@ -55,6 +55,8 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | Ampere         | AmpereOne       | AC03_CPU_38     | AMPERE_ERRATUM_AC03_CPU_38  |
 +----------------+-----------------+-----------------+-----------------------------+
+| Ampere         | AmpereOne AC04  | AC04_CPU_10     | AMPERE_ERRATUM_AC03_CPU_38  |
++----------------+-----------------+-----------------+-----------------------------+
 +----------------+-----------------+-----------------+-----------------------------+
 | ARM            | Cortex-A510     | #2457168        | ARM64_ERRATUM_2457168       |
 +----------------+-----------------+-----------------+-----------------------------+
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index a2f8ff354ca67..c8cba20a4d11b 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -423,7 +423,7 @@ config AMPERE_ERRATUM_AC03_CPU_38
 	default y
 	help
 	  This option adds an alternative code sequence to work around Ampere
-	  erratum AC03_CPU_38 on AmpereOne.
+	  errata AC03_CPU_38 and AC04_CPU_10 on AmpereOne.
 
 	  The affected design reports FEAT_HAFDBS as not implemented in
 	  ID_AA64MMFR1_EL1.HAFDBS, but (V)TCR_ELx.{HA,HD} are not RES0
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h
index 5fd7caea44193..5a7dfeb8e8eb5 100644
--- a/arch/arm64/include/asm/cputype.h
+++ b/arch/arm64/include/asm/cputype.h
@@ -143,6 +143,7 @@
 #define APPLE_CPU_PART_M2_AVALANCHE_MAX	0x039
 
 #define AMPERE_CPU_PART_AMPERE1		0xAC3
+#define AMPERE_CPU_PART_AMPERE1A	0xAC4
 
 #define MICROSOFT_CPU_PART_AZURE_COBALT_100	0xD49 /* Based on r0p0 of ARM Neoverse N2 */
 
@@ -212,6 +213,7 @@
 #define MIDR_APPLE_M2_BLIZZARD_MAX MIDR_CPU_MODEL(ARM_CPU_IMP_APPLE, APPLE_CPU_PART_M2_BLIZZARD_MAX)
 #define MIDR_APPLE_M2_AVALANCHE_MAX MIDR_CPU_MODEL(ARM_CPU_IMP_APPLE, APPLE_CPU_PART_M2_AVALANCHE_MAX)
 #define MIDR_AMPERE1 MIDR_CPU_MODEL(ARM_CPU_IMP_AMPERE, AMPERE_CPU_PART_AMPERE1)
+#define MIDR_AMPERE1A MIDR_CPU_MODEL(ARM_CPU_IMP_AMPERE, AMPERE_CPU_PART_AMPERE1A)
 #define MIDR_MICROSOFT_AZURE_COBALT_100 MIDR_CPU_MODEL(ARM_CPU_IMP_MICROSOFT, MICROSOFT_CPU_PART_AZURE_COBALT_100)
 
 /* Fujitsu Erratum 010001 affects A64FX 1.0 and 1.1, (v0r0 and v1r0) */
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index f6b6b45073571..dfefbdf4073a6 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -456,6 +456,14 @@ static const struct midr_range erratum_spec_ssbs_list[] = {
 };
 #endif
 
+#ifdef CONFIG_AMPERE_ERRATUM_AC03_CPU_38
+static const struct midr_range erratum_ac03_cpu_38_list[] = {
+	MIDR_ALL_VERSIONS(MIDR_AMPERE1),
+	MIDR_ALL_VERSIONS(MIDR_AMPERE1A),
+	{},
+};
+#endif
+
 const struct arm64_cpu_capabilities arm64_errata[] = {
 #ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE
 	{
@@ -772,7 +780,7 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 	{
 		.desc = "AmpereOne erratum AC03_CPU_38",
 		.capability = ARM64_WORKAROUND_AMPERE_AC03_CPU_38,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_AMPERE1),
+		ERRATA_MIDR_RANGE_LIST(erratum_ac03_cpu_38_list),
 	},
 #endif
 	{
-- 
2.46.0

Re: [PATCH v2] arm64: errata: Enable the AC03_CPU_38 workaround for ampere1a

[Oliver Upton]

On Tue, Aug 27, 2024 at 02:17:01PM -0700, D Scott Phillips wrote:
> The ampere1a cpu is affected by erratum AC04_CPU_10 which is the same
> bug as AC03_CPU_38. Add ampere1a to the AC03_CPU_38 workaround midr list.
> 
> Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com>

You'll probably want to cc this to stable, that can be handled when the
patch is applied though.

Acked-by: Oliver Upton <oliver.upton@linux.dev>

-- 
Thanks,
Oliver

Re: [PATCH v2] arm64: errata: Enable the AC03_CPU_38 workaround for ampere1a

[Will Deacon]

On Tue, 27 Aug 2024 14:17:01 -0700, D Scott Phillips wrote:
> The ampere1a cpu is affected by erratum AC04_CPU_10 which is the same
> bug as AC03_CPU_38. Add ampere1a to the AC03_CPU_38 workaround midr list.
> 
> 

Applied to arm64 (for-next/errata), thanks!

[1/1] arm64: errata: Enable the AC03_CPU_38 workaround for ampere1a
      https://git.kernel.org/arm64/c/db0d8a84348b 

Cheers,
-- 
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev