From: Zeng Heng <zengheng4@huawei.com>
Date: Wed, 3 Jun 2026 06:20:24 +0000 (+0800)
Subject: arm64: cpufeature: Add WORKAROUND_DISABLE_CNP capability
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=25996982ebcf8242c9e44589f8dd1ed760df8ac0;p=thirdparty%2Fkernel%2Flinux.git

arm64: cpufeature: Add WORKAROUND_DISABLE_CNP capability

The NVIDIA Carmel CNP erratum is not the only case requiring CNP to be
disabled. Abstract this into a common WORKAROUND_DISABLE_CNP capability
to facilitate adding errata for future chips and reduce duplicate
checks in has_useable_cnp().

This serves as a prerequisite for the subsequent Hisilicon erratum
162100125.

Suggested-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Wei Xu <xuwei5@hisilicon.com>
Signed-off-by: Will Deacon <will@kernel.org>
---

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index fe60738e5943b..f297517a83b90 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1315,9 +1315,13 @@ config QCOM_FALKOR_ERRATUM_E1041
 
 	  If unsure, say Y.
 
+config ARM64_WORKAROUND_DISABLE_CNP
+	bool
+
 config NVIDIA_CARMEL_CNP_ERRATUM
 	bool "NVIDIA Carmel CNP: CNP on Carmel semantically different than ARM cores"
 	default y
+	select ARM64_WORKAROUND_DISABLE_CNP
 	help
 	  If CNP is enabled on Carmel cores, non-sharable TLBIs on a core will not
 	  invalidate shared TLB entries installed by a different core, as it would
diff --git a/arch/arm64/include/asm/cpucaps.h b/arch/arm64/include/asm/cpucaps.h
index d0d3cdd5763ca..25c61cda901c5 100644
--- a/arch/arm64/include/asm/cpucaps.h
+++ b/arch/arm64/include/asm/cpucaps.h
@@ -58,8 +58,8 @@ cpucap_is_possible(const unsigned int cap)
 		return IS_ENABLED(CONFIG_ARM64_ERRATUM_2658417);
 	case ARM64_WORKAROUND_CAVIUM_23154:
 		return IS_ENABLED(CONFIG_CAVIUM_ERRATUM_23154);
-	case ARM64_WORKAROUND_NVIDIA_CARMEL_CNP:
-		return IS_ENABLED(CONFIG_NVIDIA_CARMEL_CNP_ERRATUM);
+	case ARM64_WORKAROUND_DISABLE_CNP:
+		return IS_ENABLED(CONFIG_ARM64_WORKAROUND_DISABLE_CNP);
 	case ARM64_WORKAROUND_REPEAT_TLBI:
 		return IS_ENABLED(CONFIG_ARM64_WORKAROUND_REPEAT_TLBI);
 	case ARM64_WORKAROUND_SPECULATIVE_SSBS:
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 5377e4c2eba2b..08eb9d6545d13 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -608,6 +608,15 @@ static const struct midr_range erratum_ac04_cpu_23_list[] = {
 };
 #endif
 
+#ifdef CONFIG_ARM64_WORKAROUND_DISABLE_CNP
+static const struct midr_range cnp_erratum_cpus[] = {
+#ifdef CONFIG_NVIDIA_CARMEL_CNP_ERRATUM
+	MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
+#endif
+	{},
+};
+#endif
+
 const struct arm64_cpu_capabilities arm64_errata[] = {
 #ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE
 	{
@@ -801,12 +810,12 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 				  1, 0),
 	},
 #endif
-#ifdef CONFIG_NVIDIA_CARMEL_CNP_ERRATUM
+#ifdef CONFIG_ARM64_WORKAROUND_DISABLE_CNP
 	{
 		/* NVIDIA Carmel */
 		.desc = "NVIDIA Carmel CNP erratum",
-		.capability = ARM64_WORKAROUND_NVIDIA_CARMEL_CNP,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
+		.capability = ARM64_WORKAROUND_DISABLE_CNP,
+		ERRATA_MIDR_RANGE_LIST(cnp_erratum_cpus),
 	},
 #endif
 #ifdef CONFIG_ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 6d53bb15cf7bb..20c5f24f74a91 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1785,7 +1785,7 @@ has_useable_cnp(const struct arm64_cpu_capabilities *entry, int scope)
 	if (is_kdump_kernel())
 		return false;
 
-	if (cpus_have_cap(ARM64_WORKAROUND_NVIDIA_CARMEL_CNP))
+	if (cpus_have_cap(ARM64_WORKAROUND_DISABLE_CNP))
 		return false;
 
 	return has_cpuid_feature(entry, scope);
diff --git a/arch/arm64/tools/cpucaps b/arch/arm64/tools/cpucaps
index 811c2479e82d6..9b85a84f6fd49 100644
--- a/arch/arm64/tools/cpucaps
+++ b/arch/arm64/tools/cpucaps
@@ -120,7 +120,7 @@ WORKAROUND_CAVIUM_TX2_219_PRFM
 WORKAROUND_CAVIUM_TX2_219_TVM
 WORKAROUND_CLEAN_CACHE
 WORKAROUND_DEVICE_LOAD_ACQUIRE
-WORKAROUND_NVIDIA_CARMEL_CNP
+WORKAROUND_DISABLE_CNP
 WORKAROUND_PMUV3_IMPDEF_TRAPS
 WORKAROUND_QCOM_FALKOR_E1003
 WORKAROUND_QCOM_ORYON_CNTVOFF