[PATCH 10/12] arm64: Add MIDR-based overrides for ID_AA64MMFR4_EL1.E2H0

Marc Zyngier maz at kernel.org
Mon Nov 13 09:42:42 PST 2023


None the Apple M1/M2 CPUs effectively implement E2H=0, and M2
doesn't correctly implement NV1=1 (the EL2 S1 PTW seems to barf
on the nVHE format).

Override ID_AA64MMFR4_EL1.E2H0 for these CPUs to reflect what they
actually support.

Signed-off-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kernel/idreg-override.c | 36 ++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c
index 57c145bf50b7..f7be459e5ff3 100644
--- a/arch/arm64/kernel/idreg-override.c
+++ b/arch/arm64/kernel/idreg-override.c
@@ -326,7 +326,43 @@ struct midr_override_data {
 	const struct midr_range	ranges[];
 };
 
+static const struct midr_override_data e2h0_ni __initconst = {
+	/*
+	 * These CPUs predate FEAT_E2H0, but have HCR_EL2.E2H RES1
+	 * anyway.
+	 */
+	.feature	= "id_aa64mmfr4.e2h0=0xf",
+	.ranges	= {
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM_PRO),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM_PRO),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_ICESTORM_MAX),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M1_FIRESTORM_MAX),
+		{}
+	},
+};
+
+static const struct midr_override_data e2h0_nv1_ni __initconst = {
+	/*
+	 * These CPUs predate FEAT_E2H0, but have both HCR_EL2.E2H
+	 * RES1 and a non-functional HCR_EL2.NV1.
+	 */
+	.feature	= "id_aa64mmfr4.e2h0=0xe",
+	.ranges	= {
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD_PRO),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE_PRO),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_BLIZZARD_MAX),
+		MIDR_ALL_VERSIONS(MIDR_APPLE_M2_AVALANCHE_MAX),
+		{}
+	},
+};
+
 static const struct midr_override_data * const midr_ovr_data[] __initconst = {
+	&e2h0_ni,
+	&e2h0_nv1_ni,
 };
 
 static void __init apply_midr_overrides(void)
-- 
2.39.2




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