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From: Ryan Roberts <ryan.roberts@arm.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Mark Rutland <mark.rutland@arm.com>,
	James Morse <james.morse@arm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: [PATCH v1 3/3] arm64: cpufeature: add Neoverse-V3AE to BBML2 allow list
Date: Fri, 19 Sep 2025 15:58:30 +0100	[thread overview]
Message-ID: <20250919145832.4035534-4-ryan.roberts@arm.com> (raw)
In-Reply-To: <20250919145832.4035534-1-ryan.roberts@arm.com>

Neoverse-V3AE advertises support for BBML2 and is known to not raise
conflict aborts. So add it to the BBML2_NOABORT allow list.

However, just like Neoverse-V3, Neoverse-V3AE r0p0 and r0p1 suffer from
erratum #3053180, for which the workaround is to always observe
break-before-make requirements for affected revisions. Therefore only
add to the allow list from r0p2 onwards.

For more details see Software Developer Errata Notice (SDEN) document:
    Neoverse V3AE (MP172) SDEN v9.0, erratum 3053180
    https://developer.arm.com/documentation/SDEN-2615521/9-0/

Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---
 arch/arm64/kernel/cpufeature.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index ef269a5a37e1..61180b211293 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -2235,6 +2235,7 @@ static bool has_bbml2_noabort(const struct arm64_cpu_capabilities *caps, int sco
 	static const struct midr_range supports_bbml2_noabort_list[] = {
 		MIDR_REV_RANGE(MIDR_CORTEX_X4, 0, 3, 0xf),
 		MIDR_REV_RANGE(MIDR_NEOVERSE_V3, 0, 2, 0xf),
+		MIDR_REV_RANGE(MIDR_NEOVERSE_V3AE, 0, 2, 0xf),
 		{}
 	};
 
-- 
2.43.0


  parent reply	other threads:[~2025-09-19 14:58 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-09-19 14:58 [PATCH v1 0/3] Workarounds and optimizations for Neoverse-V3AE Ryan Roberts
2025-09-19 14:58 ` [PATCH v1 1/3] arm64: cputype: Add Neoverse-V3AE definitions Ryan Roberts
2025-09-19 14:58 ` [PATCH v1 2/3] arm64: errata: Apply workarounds for Neoverse-V3AE Ryan Roberts
2025-09-19 14:58 ` Ryan Roberts [this message]
2025-09-22 13:14 ` [PATCH v1 0/3] Workarounds and optimizations " Will Deacon
2025-09-22 13:34   ` Ryan Roberts

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