arm64: Handle mismatched cache type

Track mismatches in the cache type register (CTR_EL0), other
than the D/I min line sizes and trap user accesses if there are any.

Fixes: be68a8aaf925 ("arm64: cpufeature: Fix CTR_EL0 field definitions")
Cc: <stable@vger.kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm64/include/asm/cpucaps.h

@@ -49,7 +49,8 @@
 #define ARM64_HAS_CACHE_DIC			28
 #define ARM64_HW_DBM				29
 #define ARM64_SSBD				30
+#define ARM64_MISMATCHED_CACHE_TYPE		31
 
-#define ARM64_NCAPS				31
+#define ARM64_NCAPS				32
 
 #endif /* __ASM_CPUCAPS_H */

arch/arm64/kernel/cpu_errata.c

@@ -65,11 +65,15 @@ is_kryo_midr(const struct arm64_cpu_capabilities *entry, int scope)
 }
 
 static bool
-has_mismatched_cache_line_size(const struct arm64_cpu_capabilities *entry,
-				int scope)
+has_mismatched_cache_type(const struct arm64_cpu_capabilities *entry,
+			  int scope)
 {
 	u64 mask = CTR_CACHE_MINLINE_MASK;
 
+	/* Skip matching the min line sizes for cache type check */
+	if (entry->capability == ARM64_MISMATCHED_CACHE_TYPE)
+		mask ^= arm64_ftr_reg_ctrel0.strict_mask;
+
 	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
 	return (read_cpuid_cachetype() & mask) !=
 	       (arm64_ftr_reg_ctrel0.sys_val & mask);
@@ -615,7 +619,14 @@ const struct arm64_cpu_capabilities arm64_errata[] = {
 	{
 		.desc = "Mismatched cache line size",
 		.capability = ARM64_MISMATCHED_CACHE_LINE_SIZE,
-		.matches = has_mismatched_cache_line_size,
+		.matches = has_mismatched_cache_type,
+		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
+		.cpu_enable = cpu_enable_trap_ctr_access,
+	},
+	{
+		.desc = "Mismatched cache type",
+		.capability = ARM64_MISMATCHED_CACHE_TYPE,
+		.matches = has_mismatched_cache_type,
 		.type = ARM64_CPUCAP_LOCAL_CPU_ERRATUM,
 		.cpu_enable = cpu_enable_trap_ctr_access,
 	},