From: Linu Cherian <linu.cherian@arm.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Ryan Roberts <ryan.roberts@arm.com>,
Kevin Brodsky <kevin.brodsky@arm.com>,
Anshuman Khandual <anshuman.khandual@arm.com>,
Suzuki K Poulose <suzuki.poulose@arm.com>,
Mark Rutland <mark.rutland@arm.com>
Cc: linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org, Linu Cherian <linu.cherian@arm.com>,
Gavin Shan <gshan@redhat.com>
Subject: [PATCH v4 3/6] arm64: cpufeature: Extend bbml2_noabort support list
Date: Thu, 23 Jul 2026 10:10:30 +0530 [thread overview]
Message-ID: <20260723044034.2983651-4-linu.cherian@arm.com> (raw)
In-Reply-To: <20260723044034.2983651-1-linu.cherian@arm.com>
Add below cpus to the midr list, which supports
BBML2_NOABORT.
Cortex A520(AE)
Cortex A715
Cortex A720(AE)
Cortex A725
Neoverse N3
C1-Nano
C1-Pro
C1-Ultra
C1-Premium
C1-Ultra and C1-Premium both suffer from erratum 3683289,
where Break-Before-Make must be followed to avoid a livelock.
For both CPUs, the erratum is fixed from r1p1.
Hence we do not enable BBML2_NOABORT for CPU revisions <= r1p0.
The relevant SDENs are:
* C1-Ultra: https://developer.arm.com/documentation/111077/9-00/
* C1-Premium: https://developer.arm.com/documentation/111078/9-00/
Reviewed-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Linu Cherian <linu.cherian@arm.com>
---
Documentation/arch/arm64/silicon-errata.rst | 4 ++++
arch/arm64/kernel/cpufeature.c | 10 ++++++++++
2 files changed, 14 insertions(+)
diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst
index 014aa1c215a1..57c778446936 100644
--- a/Documentation/arch/arm64/silicon-errata.rst
+++ b/Documentation/arch/arm64/silicon-errata.rst
@@ -242,10 +242,14 @@ stable kernels.
+----------------+-----------------+-----------------+-----------------------------+
| ARM | Neoverse-V3AE | #4193784 | ARM64_ERRATUM_4118414 |
+----------------+-----------------+-----------------+-----------------------------+
+| ARM | C1-Premium | #3683289 | N/A |
++----------------+-----------------+-----------------+-----------------------------+
| ARM | C1-Premium | #4193780 | ARM64_ERRATUM_4118414 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | C1-Pro | #4193714 | ARM64_ERRATUM_4193714 |
+----------------+-----------------+-----------------+-----------------------------+
+| ARM | C1-Ultra | #3683289 | N/A |
++----------------+-----------------+-----------------+-----------------------------+
| ARM | C1-Ultra | #4193780 | ARM64_ERRATUM_4118414 |
+----------------+-----------------+-----------------+-----------------------------+
| ARM | MMU-500 | #562869, | ARM_SMMU_MMU_500_CPRE_ERRATA|
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 9a22df0c5120..98d2cfc2dc90 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2152,6 +2152,16 @@ bool cpu_supports_bbml2_noabort(void)
MIDR_ALL_VERSIONS(MIDR_NVIDIA_OLYMPUS),
MIDR_ALL_VERSIONS(MIDR_AMPERE1),
MIDR_ALL_VERSIONS(MIDR_AMPERE1A),
+ MIDR_ALL_VERSIONS(MIDR_CORTEX_A520AE),
+ MIDR_ALL_VERSIONS(MIDR_CORTEX_A715),
+ MIDR_ALL_VERSIONS(MIDR_CORTEX_A720AE),
+ MIDR_ALL_VERSIONS(MIDR_CORTEX_A725),
+ MIDR_ALL_VERSIONS(MIDR_NEOVERSE_N3),
+ MIDR_ALL_VERSIONS(MIDR_C1_NANO),
+ MIDR_ALL_VERSIONS(MIDR_C1_PRO),
+ /* Erratum 3683289 fixed in r1p1 */
+ MIDR_RANGE(MIDR_C1_ULTRA, 1, 1, 0xf, 0xf),
+ MIDR_RANGE(MIDR_C1_PREMIUM, 1, 1, 0xf, 0xf),
{}
};
--
2.43.0
next prev parent reply other threads:[~2026-07-23 4:42 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-23 4:40 [PATCH v4 0/6] Add BBML3 cpu feature Linu Cherian
2026-07-23 4:40 ` [PATCH v4 1/6] arm64: cputype: Add Cortex-A520AE definitions Linu Cherian
2026-07-23 4:40 ` [PATCH v4 2/6] arm64: cputype: Add C1-Nano definitions Linu Cherian
2026-07-23 4:40 ` Linu Cherian [this message]
2026-07-23 7:26 ` [PATCH v4 3/6] arm64: cpufeature: Extend bbml2_noabort support list Anshuman Khandual
2026-07-23 4:40 ` [PATCH v4 4/6] arm64: sysreg: Add BBM_3 Linu Cherian
2026-07-23 4:40 ` [PATCH v4 5/6] arm64: cpufeature: Rename BBML2_NOABORT as BBML3 Linu Cherian
2026-08-06 17:11 ` Will Deacon
2026-07-23 4:40 ` [PATCH v4 6/6] arm64: cpufeature: Detect BBML3 based on ID_AA64MMFR2_EL1.BBM Linu Cherian
2026-07-31 15:13 ` Will Deacon
2026-08-03 3:52 ` Linu Cherian
2026-08-03 4:19 ` Anshuman Khandual
2026-08-04 13:51 ` Will Deacon
2026-08-05 9:20 ` Linu Cherian
2026-08-06 11:26 ` Will Deacon
2026-08-06 17:11 ` [PATCH v4 0/6] Add BBML3 cpu feature Will Deacon
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