1  // Copyright (c), 2022, KNS Group LLC (YADRO)
 2  //
 3  // Use of this source code is governed by an MIT-style
 4  // license that can be found in the LICENSE file or at
 5  // https://opensource.org/licenses/MIT.
 6  
 7  #include <biscuit/cpuinfo.hpp>
 8  
 9  namespace biscuit {
10  
11  bool CPUInfo::Has(RISCVExtension extension) const {
12  #if defined(__linux__) && defined(__riscv)
13      const static uint64_t features = getauxval(AT_HWCAP) & (
14                              COMPAT_HWCAP_ISA_I |
15                              COMPAT_HWCAP_ISA_M |
16                              COMPAT_HWCAP_ISA_A |
17                              COMPAT_HWCAP_ISA_F |
18                              COMPAT_HWCAP_ISA_D |
19                              COMPAT_HWCAP_ISA_C |
20                              COMPAT_HWCAP_ISA_V
21      );
22  #else
23      const static uint64_t features = 0;
24  #endif
25  
26      return (features & static_cast<uint64_t>(extension)) != 0;
27  }
28  
29  uint32_t CPUInfo::GetVlenb() const {
30      if(Has(RISCVExtension::V)) {
31          static CSRReader<CSR::VLenb> csrReader;
32          const static auto getVLEN = csrReader.GetCode<uint32_t (*)()>();
33          return getVLEN();
34      }
35  
36      return 0;
37  }
38  
39  } // namespace biscuit