1/*
2 * Copyright (C) 2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include "instruction_set_features_arm64.h"
18
19#include <fstream>
20#include <sstream>
21
22#include "base/stringprintf.h"
23#include "utils.h"  // For Trim.
24
25namespace art {
26
27const Arm64InstructionSetFeatures* Arm64InstructionSetFeatures::FromVariant(
28    const std::string& variant, std::string* error_msg) {
29  const bool smp = true;  // Conservative default.
30
31  // Look for variants that need a fix for a53 erratum 835769.
32  static const char* arm64_variants_with_a53_835769_bug[] = {
33      "default", "generic", "cortex-a53"  // Pessimistically assume all generic ARM64s are A53s.
34  };
35  bool needs_a53_835769_fix = FindVariantInArray(arm64_variants_with_a53_835769_bug,
36                                                 arraysize(arm64_variants_with_a53_835769_bug),
37                                                 variant);
38
39  if (!needs_a53_835769_fix) {
40    // Check to see if this is an expected variant.
41    static const char* arm64_known_variants[] = {
42        "denver64", "kryo", "exynos-m1"
43    };
44    if (!FindVariantInArray(arm64_known_variants, arraysize(arm64_known_variants), variant)) {
45      std::ostringstream os;
46      os << "Unexpected CPU variant for Arm64: " << variant;
47      *error_msg = os.str();
48      return nullptr;
49    }
50  }
51
52  // The variants that need a fix for 843419 are the same that need a fix for 835769.
53  bool needs_a53_843419_fix = needs_a53_835769_fix;
54
55  return new Arm64InstructionSetFeatures(smp, needs_a53_835769_fix, needs_a53_843419_fix);
56}
57
58const Arm64InstructionSetFeatures* Arm64InstructionSetFeatures::FromBitmap(uint32_t bitmap) {
59  bool smp = (bitmap & kSmpBitfield) != 0;
60  bool is_a53 = (bitmap & kA53Bitfield) != 0;
61  return new Arm64InstructionSetFeatures(smp, is_a53, is_a53);
62}
63
64const Arm64InstructionSetFeatures* Arm64InstructionSetFeatures::FromCppDefines() {
65  const bool smp = true;
66  const bool is_a53 = true;  // Pessimistically assume all ARM64s are A53s.
67  return new Arm64InstructionSetFeatures(smp, is_a53, is_a53);
68}
69
70const Arm64InstructionSetFeatures* Arm64InstructionSetFeatures::FromCpuInfo() {
71  // Look in /proc/cpuinfo for features we need.  Only use this when we can guarantee that
72  // the kernel puts the appropriate feature flags in here.  Sometimes it doesn't.
73  bool smp = false;
74  const bool is_a53 = true;  // Conservative default.
75
76  std::ifstream in("/proc/cpuinfo");
77  if (!in.fail()) {
78    while (!in.eof()) {
79      std::string line;
80      std::getline(in, line);
81      if (!in.eof()) {
82        LOG(INFO) << "cpuinfo line: " << line;
83        if (line.find("processor") != std::string::npos && line.find(": 1") != std::string::npos) {
84          smp = true;
85        }
86      }
87    }
88    in.close();
89  } else {
90    LOG(ERROR) << "Failed to open /proc/cpuinfo";
91  }
92  return new Arm64InstructionSetFeatures(smp, is_a53, is_a53);
93}
94
95const Arm64InstructionSetFeatures* Arm64InstructionSetFeatures::FromHwcap() {
96  bool smp = sysconf(_SC_NPROCESSORS_CONF) > 1;
97  const bool is_a53 = true;  // Pessimistically assume all ARM64s are A53s.
98  return new Arm64InstructionSetFeatures(smp, is_a53, is_a53);
99}
100
101const Arm64InstructionSetFeatures* Arm64InstructionSetFeatures::FromAssembly() {
102  UNIMPLEMENTED(WARNING);
103  return FromCppDefines();
104}
105
106bool Arm64InstructionSetFeatures::Equals(const InstructionSetFeatures* other) const {
107  if (kArm64 != other->GetInstructionSet()) {
108    return false;
109  }
110  const Arm64InstructionSetFeatures* other_as_arm = other->AsArm64InstructionSetFeatures();
111  return fix_cortex_a53_835769_ == other_as_arm->fix_cortex_a53_835769_;
112}
113
114uint32_t Arm64InstructionSetFeatures::AsBitmap() const {
115  return (IsSmp() ? kSmpBitfield : 0) | (fix_cortex_a53_835769_ ? kA53Bitfield : 0);
116}
117
118std::string Arm64InstructionSetFeatures::GetFeatureString() const {
119  std::string result;
120  if (IsSmp()) {
121    result += "smp";
122  } else {
123    result += "-smp";
124  }
125  if (fix_cortex_a53_835769_) {
126    result += ",a53";
127  } else {
128    result += ",-a53";
129  }
130  return result;
131}
132
133const InstructionSetFeatures* Arm64InstructionSetFeatures::AddFeaturesFromSplitString(
134    const bool smp, const std::vector<std::string>& features, std::string* error_msg) const {
135  bool is_a53 = fix_cortex_a53_835769_;
136  for (auto i = features.begin(); i != features.end(); i++) {
137    std::string feature = Trim(*i);
138    if (feature == "a53") {
139      is_a53 = true;
140    } else if (feature == "-a53") {
141      is_a53 = false;
142    } else {
143      *error_msg = StringPrintf("Unknown instruction set feature: '%s'", feature.c_str());
144      return nullptr;
145    }
146  }
147  return new Arm64InstructionSetFeatures(smp, is_a53, is_a53);
148}
149
150}  // namespace art
151