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 #ifndef ART_RUNTIME_ARCH_ARM64_INSTRUCTION_SET_FEATURES_ARM64_H_
18 #define ART_RUNTIME_ARCH_ARM64_INSTRUCTION_SET_FEATURES_ARM64_H_
19 
20 #include "arch/instruction_set_features.h"
21 
22 namespace art {
23 
24 // Instruction set features relevant to the ARM64 architecture.
25 class Arm64InstructionSetFeatures FINAL : public InstructionSetFeatures {
26  public:
27   // Process a CPU variant string like "krait" or "cortex-a15" and create InstructionSetFeatures.
28   static const Arm64InstructionSetFeatures* FromVariant(const std::string& variant,
29                                                         std::string* error_msg);
30 
31   // Parse a bitmap and create an InstructionSetFeatures.
32   static const Arm64InstructionSetFeatures* FromBitmap(uint32_t bitmap);
33 
34   // Turn C pre-processor #defines into the equivalent instruction set features.
35   static const Arm64InstructionSetFeatures* FromCppDefines();
36 
37   // Process /proc/cpuinfo and use kRuntimeISA to produce InstructionSetFeatures.
38   static const Arm64InstructionSetFeatures* FromCpuInfo();
39 
40   // Process the auxiliary vector AT_HWCAP entry and use kRuntimeISA to produce
41   // InstructionSetFeatures.
42   static const Arm64InstructionSetFeatures* FromHwcap();
43 
44   // Use assembly tests of the current runtime (ie kRuntimeISA) to determine the
45   // InstructionSetFeatures. This works around kernel bugs in AT_HWCAP and /proc/cpuinfo.
46   static const Arm64InstructionSetFeatures* FromAssembly();
47 
48   bool Equals(const InstructionSetFeatures* other) const OVERRIDE;
49 
GetInstructionSet()50   InstructionSet GetInstructionSet() const OVERRIDE {
51     return kArm64;
52   }
53 
54   uint32_t AsBitmap() const OVERRIDE;
55 
56   // Return a string of the form "a53" or "none".
57   std::string GetFeatureString() const OVERRIDE;
58 
59   // Generate code addressing Cortex-A53 erratum 835769?
NeedFixCortexA53_835769()60   bool NeedFixCortexA53_835769() const {
61       return fix_cortex_a53_835769_;
62   }
63 
64   // Generate code addressing Cortex-A53 erratum 843419?
NeedFixCortexA53_843419()65   bool NeedFixCortexA53_843419() const {
66       return fix_cortex_a53_843419_;
67   }
68 
~Arm64InstructionSetFeatures()69   virtual ~Arm64InstructionSetFeatures() {}
70 
71  protected:
72   // Parse a vector of the form "a53" adding these to a new ArmInstructionSetFeatures.
73   const InstructionSetFeatures*
74       AddFeaturesFromSplitString(const bool smp, const std::vector<std::string>& features,
75                                  std::string* error_msg) const OVERRIDE;
76 
77  private:
Arm64InstructionSetFeatures(bool smp,bool needs_a53_835769_fix,bool needs_a53_843419_fix)78   Arm64InstructionSetFeatures(bool smp, bool needs_a53_835769_fix, bool needs_a53_843419_fix)
79       : InstructionSetFeatures(smp),
80         fix_cortex_a53_835769_(needs_a53_835769_fix),
81         fix_cortex_a53_843419_(needs_a53_843419_fix) {
82   }
83 
84   // Bitmap positions for encoding features as a bitmap.
85   enum {
86     kSmpBitfield = 1,
87     kA53Bitfield = 2,
88   };
89 
90   const bool fix_cortex_a53_835769_;
91   const bool fix_cortex_a53_843419_;
92 
93   DISALLOW_COPY_AND_ASSIGN(Arm64InstructionSetFeatures);
94 };
95 
96 }  // namespace art
97 
98 #endif  // ART_RUNTIME_ARCH_ARM64_INSTRUCTION_SET_FEATURES_ARM64_H_
99