arm64: cpufeature: Add HAFT to cpucap_is_possible()

For consistency with other cpucaps, handle the configuration check for
ARM64_HAFT in cpucap_is_possible() rather than this being explicit in
system_supports_haft(). The configuration check will now happen
implicitly as cpus_have_final_cap() uses cpucap_is_possible() via
alternative_has_cap_unlikely().

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20241209155948.2124393-1-mark.rutland@arm.com
Signed-off-by: Will Deacon <will@kernel.org>

Author: mrutland-arm

arch/arm64/include/asm/cpucaps.h

@@ -46,6 +46,8 @@ cpucap_is_possible(const unsigned int cap)
 		return IS_ENABLED(CONFIG_ARM64_POE);
 	case ARM64_HAS_GCS:
 		return IS_ENABLED(CONFIG_ARM64_GCS);
+	case ARM64_HAFT:
+		return IS_ENABLED(CONFIG_ARM64_HAFT);
 	case ARM64_UNMAP_KERNEL_AT_EL0:
 		return IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0);
 	case ARM64_WORKAROUND_843419:

arch/arm64/include/asm/cpufeature.h

@@ -852,8 +852,7 @@ static inline bool system_supports_gcs(void)
 
 static inline bool system_supports_haft(void)
 {
-	return IS_ENABLED(CONFIG_ARM64_HAFT) &&
-		cpus_have_final_cap(ARM64_HAFT);
+	return cpus_have_final_cap(ARM64_HAFT);
 }
 
 static __always_inline bool system_supports_mpam(void)