Add aarch64 midr_el1 implementation

include/internal/cpuid_aarch64.h

@@ -0,0 +1,28 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef CPU_FEATURES_INCLUDE_CPUID_AARCH64_H_
+#define CPU_FEATURES_INCLUDE_CPUID_AARCH64_H_
+
+#include <stdint.h>
+
+#include "cpu_features_macros.h"
+
+CPU_FEATURES_START_CPP_NAMESPACE
+
+uint64_t GetMidrEl1();
+
+CPU_FEATURES_END_CPP_NAMESPACE
+
+#endif // CPU_FEATURES_INCLUDE_CPUID_AARCH64_H_

src/impl_aarch64_cpuid.c

@@ -0,0 +1,39 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "cpu_features_macros.h"
+
+#ifdef CPU_FEATURES_ARCH_AARCH64
+#ifdef CPU_FEATURES_OS_FREEBSD
+#if (defined(CPU_FEATURES_COMPILER_GCC) || defined(CPU_FEATURES_COMPILER_CLANG))
+
+#include "internal/cpuid_aarch64.h"
+
+#ifdef CPU_FEATURES_MOCK_CPUID_AARCH64
+// Implementation will be provided by test/cpuinfo_aarch64_test.cc.
+#else
+
+uint64_t GetMidrEl1() {
+ uint64_t midr_el1;
+ __asm("mrs %0, MIDR_EL1" : "=r"(midr_el1));
+ return midr_el1;
+}
+#endif // CPU_FEATURES_MOCK_CPUID_AARCH64
+
+#else
+#error "Unsupported compiler, aarch64 cpuid requires either GCC or Clang."
+#endif // (defined(CPU_FEATURES_COMPILER_GCC) ||
+ // defined(CPU_FEATURES_COMPILER_CLANG))
+#endif // CPU_FEATURES_OS_FREEBSD
+#endif // CPU_FEATURES_ARCH_AARCH64

src/impl_aarch64_freebsd.c

@@ -12,12 +12,15 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include <printf.h>
+
 #include "cpu_features_macros.h"
 
 #ifdef CPU_FEATURES_ARCH_AARCH64
 #ifdef CPU_FEATURES_OS_FREEBSD
 
 #include "cpuinfo_aarch64.h"
+#include "cpuid_aarch64.h"
 #include "impl_aarch64__base_implementation.inl"
 
 static const Aarch64Info kEmptyAarch64Info;
@@ -30,6 +33,14 @@ Aarch64Info GetAarch64Info(void) {
  kSetters[i](&info.features, true);
  }
  }
+ printf("cpuid is supported: %d", info.features.cpuid);
+ if (info.features.cpuid) {
+ const uint64_t midr_el1 = GetMidrEl1();
+ info.implementer = ExtractBitRange(midr_el1, 31, 24);
+ info.variant = ExtractBitRange(midr_el1, 23, 20);
+ info.part = ExtractBitRange(midr_el1, 15, 4);
+ info.revision = ExtractBitRange(midr_el1, 3, 0);
+ }
  return info;
 }