arm64/cpuinfo: Remove references to reserved cache type

In 155433cb ("arm64: cache: Remove support for ASID-tagged VIVT
I-caches") we removed all the support fir AIVIVT cache types and renamed
all references to the field to say "unknown" since support for AIVIVT
caches was removed from the architecture. Some confusion has resulted since
the corresponding change to the architecture left the value named as
AIVIVT but documented it as reserved in v8, refactor the code so we don't
define the constant instead. This will help with automatic generation of
this register field since it means we care less about the correspondence
with the ARM.

No functional change, the value displayed to userspace is unchanged.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220704170302.2609529-2-broonie@kernel.orgSigned-off-by: Will Deacon <will@kernel.org>

arch/arm64/include/asm/cache.h

@@ -25,7 +25,6 @@
 #define CTR_L1IP(ctr)		(((ctr) >> CTR_L1IP_SHIFT) & CTR_L1IP_MASK)
 
 #define ICACHE_POLICY_VPIPT	0
-#define ICACHE_POLICY_RESERVED	1
 #define ICACHE_POLICY_VIPT	2
 #define ICACHE_POLICY_PIPT	3
 

arch/arm64/kernel/cpuinfo.c

@@ -33,12 +33,19 @@
 DEFINE_PER_CPU(struct cpuinfo_arm64, cpu_data);
 static struct cpuinfo_arm64 boot_cpu_data;
 
-static const char *icache_policy_str[] = {
-	[ICACHE_POLICY_VPIPT]		= "VPIPT",
-	[ICACHE_POLICY_RESERVED]	= "RESERVED/UNKNOWN",
-	[ICACHE_POLICY_VIPT]		= "VIPT",
-	[ICACHE_POLICY_PIPT]		= "PIPT",
-};
+static inline const char *icache_policy_str(int l1ip)
+{
+	switch (l1ip) {
+	case ICACHE_POLICY_VPIPT:
+		return "VPIPT";
+	case ICACHE_POLICY_VIPT:
+		return "VIPT";
+	case ICACHE_POLICY_PIPT:
+		return "PIPT";
+	default:
+		return "RESERVED/UNKNOWN";
+	}
+}
 
 unsigned long __icache_flags;
 
@@ -347,14 +354,14 @@ static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
 	case ICACHE_POLICY_VPIPT:
 		set_bit(ICACHEF_VPIPT, &__icache_flags);
 		break;
-	case ICACHE_POLICY_RESERVED:
 	case ICACHE_POLICY_VIPT:
+	default:
 		/* Assume aliasing */
 		set_bit(ICACHEF_ALIASING, &__icache_flags);
 		break;
 	}
 
-	pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str[l1ip], cpu);
+	pr_info("Detected %s I-cache on CPU%d\n", icache_policy_str(l1ip), cpu);
 }
 
 static void __cpuinfo_store_cpu_32bit(struct cpuinfo_32bit *info)