arm64: Kill detection of VPIPT i-cache policy

Since the kernel will never run on a system with the VPIPT i-cache
policy, drop the detection code altogether.

Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20231204143606.1806432-3-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

Author: Marc Zyngier

arch/arm64/include/asm/cache.h

@@ -58,7 +58,6 @@ static inline unsigned int arch_slab_minalign(void)
 #define CTR_L1IP(ctr)		SYS_FIELD_GET(CTR_EL0, L1Ip, ctr)
 
 #define ICACHEF_ALIASING	0
-#define ICACHEF_VPIPT		1
 extern unsigned long __icache_flags;
 
 /*
@@ -70,11 +69,6 @@ static inline int icache_is_aliasing(void)
 	return test_bit(ICACHEF_ALIASING, &__icache_flags);
 }
 
-static __always_inline int icache_is_vpipt(void)
-{
-	return test_bit(ICACHEF_VPIPT, &__icache_flags);
-}
-
 static inline u32 cache_type_cwg(void)
 {
 	return SYS_FIELD_GET(CTR_EL0, CWG, read_cpuid_cachetype());

arch/arm64/kernel/cpuinfo.c

@@ -36,8 +36,6 @@ static struct cpuinfo_arm64 boot_cpu_data;
 static inline const char *icache_policy_str(int l1ip)
 {
 	switch (l1ip) {
-	case CTR_EL0_L1Ip_VPIPT:
-		return "VPIPT";
 	case CTR_EL0_L1Ip_VIPT:
 		return "VIPT";
 	case CTR_EL0_L1Ip_PIPT:
@@ -388,9 +386,6 @@ static void cpuinfo_detect_icache_policy(struct cpuinfo_arm64 *info)
 	switch (l1ip) {
 	case CTR_EL0_L1Ip_PIPT:
 		break;
-	case CTR_EL0_L1Ip_VPIPT:
-		set_bit(ICACHEF_VPIPT, &__icache_flags);
-		break;
 	case CTR_EL0_L1Ip_VIPT:
 	default:
 		/* Assume aliasing */