arm64: Remove cpus_have_const_cap()

There are no longer any users of cpus_have_const_cap(), and therefore it
can be removed.

Remove cpus_have_const_cap(). At the same time, remove
__cpus_have_const_cap(), as this is a trivial wrapper of
alternative_has_cap_unlikely(), which can be used directly instead.

The comment for __system_matches_cap() is updated to no longer refer to
cpus_have_const_cap(). As we have a number of ways to check the cpucaps,
the specific suggestions are removed.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Kristina Martsenko <kristina.martsenko@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Author: mrutland-arm

arch/arm64/include/asm/cpufeature.h

@@ -462,19 +462,6 @@ static __always_inline bool cpus_have_cap(unsigned int num)
 	return arch_test_bit(num, system_cpucaps);
 }
 
-/*
- * Test for a capability without a runtime check.
- *
- * Before capabilities are finalized, this returns false.
- * After capabilities are finalized, this is patched to avoid a runtime check.
- *
- * @num must be a compile-time constant.
- */
-static __always_inline bool __cpus_have_const_cap(int num)
-{
-	return alternative_has_cap_unlikely(num);
-}
-
 /*
  * Test for a capability without a runtime check.
  *
@@ -487,7 +474,7 @@ static __always_inline bool __cpus_have_const_cap(int num)
 static __always_inline bool cpus_have_final_boot_cap(int num)
 {
 	if (boot_capabilities_finalized())
-		return __cpus_have_const_cap(num);
+		return alternative_has_cap_unlikely(num);
 	else
 		BUG();
 }
@@ -504,32 +491,11 @@ static __always_inline bool cpus_have_final_boot_cap(int num)
 static __always_inline bool cpus_have_final_cap(int num)
 {
 	if (system_capabilities_finalized())
-		return __cpus_have_const_cap(num);
+		return alternative_has_cap_unlikely(num);
 	else
 		BUG();
 }
 
-/*
- * Test for a capability, possibly with a runtime check for non-hyp code.
- *
- * For hyp code, this behaves the same as cpus_have_final_cap().
- *
- * For non-hyp code:
- * Before capabilities are finalized, this behaves as cpus_have_cap().
- * After capabilities are finalized, this is patched to avoid a runtime check.
- *
- * @num must be a compile-time constant.
- */
-static __always_inline bool cpus_have_const_cap(int num)
-{
-	if (is_hyp_code())
-		return cpus_have_final_cap(num);
-	else if (system_capabilities_finalized())
-		return __cpus_have_const_cap(num);
-	else
-		return cpus_have_cap(num);
-}
-
 static inline int __attribute_const__
 cpuid_feature_extract_signed_field_width(u64 features, int field, int width)
 {

arch/arm64/kernel/cpufeature.c

@@ -3322,7 +3322,6 @@ EXPORT_SYMBOL_GPL(this_cpu_has_cap);
  * This helper function is used in a narrow window when,
  * - The system wide safe registers are set with all the SMP CPUs and,
  * - The SYSTEM_FEATURE system_cpucaps may not have been set.
- * In all other cases cpus_have_{const_}cap() should be used.
  */
 static bool __maybe_unused __system_matches_cap(unsigned int n)
 {