arm64: arch_timer: Add workaround for ARM erratum 1188873

When running on Cortex-A76, a timer access from an AArch32 EL0
task may end up with a corrupted value or register. The workaround for
this is to trap these accesses at EL1/EL2 and execute them there.

This only affects versions r0p0, r1p0 and r2p0 of the CPU.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index 20be4c57..cde9489 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -697,6 +697,14 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 		.matches = has_ssbd_mitigation,
 	},
 #endif
+#ifdef CONFIG_ARM64_ERRATUM_1188873
+	{
+		/* Cortex-A76 r0p0 to r2p0 */
+		.desc = "ARM erratum 1188873",
+		.capability = ARM64_WORKAROUND_1188873,
+		ERRATA_MIDR_RANGE(MIDR_CORTEX_A76, 0, 0, 2, 0),
+	},
+#endif
 	{
 	}
 };