[PATCH v3 2/2] arm64: kernel: Disable CNP on HiSilicon HIP09

[Zeng Heng]

From: Zeng Heng <zengheng4@xxxxxxxxxx>

HiSilicon HIP09 implements TLB entry matching behavior that deviates
from the ARM architecture specification when the CNP (Common not Private)
bit is set in TTBRx_ELx.

When TTBRx.CNP=1, TLB entries may be incorrectly shared between CPU
cores, leading to TLB conflicts and stale mappings. This affects
coherency and can result in incorrect translations.

Add the hardware erratum workaround (Hisilicon erratum 162100125) to
disable CNP on affected HIP09 cores.

Co-developed-by: Tong Tiangen <tongtiangen@xxxxxxxxxx>
Signed-off-by: Tong Tiangen <tongtiangen@xxxxxxxxxx>
Signed-off-by: Zeng Heng <zengheng4@xxxxxxxxxx>
---
 Documentation/arch/arm64/silicon-errata.rst |  2 ++
 arch/arm64/Kconfig                          | 16 ++++++++++++++++
 arch/arm64/kernel/cpu_errata.c              | 13 ++++++++++---
 3 files changed, 28 insertions(+), 3 deletions(-)

diff --git a/Documentation/arch/arm64/silicon-errata.rst b/Documentation/arch/arm64/silicon-errata.rst
index 211119ce7adc..cd50059edb85 100644
--- a/Documentation/arch/arm64/silicon-errata.rst
+++ b/Documentation/arch/arm64/silicon-errata.rst
@@ -284,6 +284,8 @@ stable kernels.
 +----------------+-----------------+-----------------+-----------------------------+
 | Hisilicon      | Hip09           | #162100801      | HISILICON_ERRATUM_162100801 |
 +----------------+-----------------+-----------------+-----------------------------+
+| Hisilicon      | Hip09           | #162100125      | HISILICON_ERRATUM_162100125 |
++----------------+-----------------+-----------------+-----------------------------+
 +----------------+-----------------+-----------------+-----------------------------+
 | Qualcomm Tech. | Kryo/Falkor v1  | E1003           | QCOM_FALKOR_ERRATUM_1003    |
 +----------------+-----------------+-----------------+-----------------------------+
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index f297517a83b9..75638e37883d 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -1273,6 +1273,22 @@ config HISILICON_ERRATUM_162100801

 	  If unsure, say Y.

+config HISILICON_ERRATUM_162100125
+	bool "Hisilicon erratum 162100125"
+	default y
+	select ARM64_WORKAROUND_DISABLE_CNP
+	help
+	  On HiSilicon HIP09, TLB entry matching behavior when CNP
+	  (TTBRx.CNP=1) is enabled differs from the ARM architecture
+	  specification.
+
+	  TLB entries may be incorrectly shared between CPUs, potentially
+	  causing TLB conflicts and stale mappings.
+
+	  Disable CNP support for affected HiSilicon HIP09 cores.
+
+	  If unsure, say Y.
+
 config QCOM_FALKOR_ERRATUM_1003
 	bool "Falkor E1003: Incorrect translation due to ASID change"
 	default y
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index b0db946568b7..02e0ee5c948c 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -608,6 +608,14 @@ 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[] = {
+	MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
+	MIDR_ALL_VERSIONS(MIDR_HISI_HIP09),
+	{},
+};
+#endif
+
 const struct arm64_cpu_capabilities arm64_errata[] = {
 #ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE
 	{
@@ -803,10 +811,9 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 #endif
 #ifdef CONFIG_ARM64_WORKAROUND_DISABLE_CNP
 	{
-		/* NVIDIA Carmel */
-		.desc = "NVIDIA Carmel CNP erratum",
+		.desc = "NVIDIA Carmel CNP erratum, or Hisilicon erratum 162100125",
 		.capability = ARM64_WORKAROUND_DISABLE_CNP,
-		ERRATA_MIDR_ALL_VERSIONS(MIDR_NVIDIA_CARMEL),
+		ERRATA_MIDR_RANGE_LIST(cnp_erratum_cpus),
 	},
 #endif
 #ifdef CONFIG_ARM64_WORKAROUND_TRBE_OVERWRITE_FILL_MODE
--
2.43.0