/*
* Runtime CPU detection
* (C) 2009-2010,2013 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/

#include <botan/cpuid.h>
#include <botan/types.h>
#include <botan/loadstor.h>
#include <botan/exceptn.h>
#include <botan/mem_ops.h>
#include <ostream>

#if defined(BOTAN_TARGET_CPU_IS_PPC_FAMILY)

#if defined(BOTAN_TARGET_OS_IS_DARWIN)
  #include <sys/sysctl.h>
#endif

#if defined(BOTAN_TARGET_OS_IS_OPENBSD)
  #include <sys/param.h>
  #include <sys/sysctl.h>
  #include <machine/cpu.h>
#endif

#endif

#if defined(BOTAN_TARGET_CPU_IS_X86_FAMILY)

#if defined(BOTAN_BUILD_COMPILER_IS_MSVC)

#include <intrin.h>

#define X86_CPUID(type, out) do { __cpuid((int*)out, type); } while(0)
#define X86_CPUID_SUBLEVEL(type, level, out) do { __cpuidex((int*)out, type, level); } while(0)

#elif defined(BOTAN_BUILD_COMPILER_IS_INTEL)

#include <ia32intrin.h>

#define X86_CPUID(type, out) do { __cpuid(out, type); } while(0)
#define X86_CPUID_SUBLEVEL(type, level, out) do { __cpuidex((int*)out, type, level); } while(0)

#elif defined(BOTAN_TARGET_ARCH_IS_X86_64) && defined(BOTAN_USE_GCC_INLINE_ASM)

#define X86_CPUID(type, out)                                                    \
   asm("cpuid\n\t" : "=a" (out[0]), "=b" (out[1]), "=c" (out[2]), "=d" (out[3]) \
       : "0" (type))

#define X86_CPUID_SUBLEVEL(type, level, out)                                    \
   asm("cpuid\n\t" : "=a" (out[0]), "=b" (out[1]), "=c" (out[2]), "=d" (out[3]) \
       : "0" (type), "2" (level))

#elif defined(BOTAN_BUILD_COMPILER_IS_GCC) || defined(BOTAN_BUILD_COMPILER_IS_CLANG)

#include <cpuid.h>

#define X86_CPUID(type, out) do { __get_cpuid(type, out, out+1, out+2, out+3); } while(0)

#define X86_CPUID_SUBLEVEL(type, level, out) \
   do { __cpuid_count(type, level, out[0], out[1], out[2], out[3]); } while(0)

#else

#warning "No way of calling cpuid for this compiler"

#define X86_CPUID(type, out) do { clear_mem(out, 4); } while(0)
#define X86_CPUID_SUBLEVEL(type, level, out) do { clear_mem(out, 4); } while(0)

#endif

#endif

namespace Botan {

u64bit CPUID::g_processor_flags[2] = { 0, 0 };
size_t CPUID::g_cache_line_size = BOTAN_TARGET_CPU_DEFAULT_CACHE_LINE_SIZE;
bool CPUID::g_initialized = false;
bool CPUID::g_little_endian = false;

namespace {

#if defined(BOTAN_TARGET_CPU_IS_PPC_FAMILY)

bool altivec_check_sysctl()
   {
#if defined(BOTAN_TARGET_OS_IS_DARWIN) || defined(BOTAN_TARGET_OS_IS_OPENBSD)

#if defined(BOTAN_TARGET_OS_IS_OPENBSD)
   int sels[2] = { CTL_MACHDEP, CPU_ALTIVEC };
#else
   // From Apple's docs
   int sels[2] = { CTL_HW, HW_VECTORUNIT };
#endif
   int vector_type = 0;
   size_t length = sizeof(vector_type);
   int error = sysctl(sels, 2, &vector_type, &length, NULL, 0);

   if(error == 0 && vector_type > 0)
      return true;
#endif

   return false;
   }

bool altivec_check_pvr_emul()
   {
   bool altivec_capable = false;

#if defined(BOTAN_TARGET_OS_IS_LINUX) || defined(BOTAN_TARGET_OS_IS_NETBSD)

   /*
   On PowerPC, MSR 287 is PVR, the Processor Version Number
   Normally it is only accessible to ring 0, but Linux and NetBSD
   (others, too, maybe?) will trap and emulate it for us.

   PVR identifiers for various AltiVec enabled CPUs. Taken from
   PearPC and Linux sources, mostly.
   */

   const u16bit PVR_G4_7400  = 0x000C;
   const u16bit PVR_G5_970   = 0x0039;
   const u16bit PVR_G5_970FX = 0x003C;
   const u16bit PVR_G5_970MP = 0x0044;
   const u16bit PVR_G5_970GX = 0x0045;
   const u16bit PVR_POWER6   = 0x003E;
   const u16bit PVR_POWER7   = 0x003F;
   const u16bit PVR_POWER8   = 0x004B;
   const u16bit PVR_CELL_PPU = 0x0070;

   // Motorola produced G4s with PVR 0x800[0123C] (at least)
   const u16bit PVR_G4_74xx_24  = 0x800;

   u32bit pvr = 0;

   asm volatile("mfspr %0, 287" : "=r" (pvr));

   // Top 16 bit suffice to identify model
   pvr >>= 16;

   altivec_capable |= (pvr == PVR_G4_7400);
   altivec_capable |= ((pvr >> 4) == PVR_G4_74xx_24);
   altivec_capable |= (pvr == PVR_G5_970);
   altivec_capable |= (pvr == PVR_G5_970FX);
   altivec_capable |= (pvr == PVR_G5_970MP);
   altivec_capable |= (pvr == PVR_G5_970GX);
   altivec_capable |= (pvr == PVR_POWER6);
   altivec_capable |= (pvr == PVR_POWER7);
   altivec_capable |= (pvr == PVR_POWER8);
   altivec_capable |= (pvr == PVR_CELL_PPU);
#endif

   return altivec_capable;
   }

#endif

}

bool CPUID::has_simd_32()
   {
#if defined(BOTAN_TARGET_SUPPORTS_SSE2)
   return CPUID::has_sse2();
#elif defined(BOTAN_TARGET_SUPPORTS_ALTIVEC)
   return CPUID::has_altivec();
#else
   return true;
#endif
   }

void CPUID::print(std::ostream& o)
   {
   o << "CPUID flags: ";

#define CPUID_PRINT(flag) do { if(has_##flag()) o << #flag << " "; } while(0)

#if defined(BOTAN_TARGET_CPU_IS_X86_FAMILY)
   CPUID_PRINT(sse2);
   CPUID_PRINT(ssse3);
   CPUID_PRINT(sse41);
   CPUID_PRINT(sse42);
   CPUID_PRINT(avx2);
   CPUID_PRINT(avx512f);

   CPUID_PRINT(rdtsc);
   CPUID_PRINT(bmi2);
   CPUID_PRINT(clmul);
   CPUID_PRINT(aes_ni);
   CPUID_PRINT(rdrand);
   CPUID_PRINT(rdseed);
   CPUID_PRINT(intel_sha);
   CPUID_PRINT(adx);
#endif

#if defined(BOTAN_TARGET_CPU_IS_PPC_FAMILY)
   CPUID_PRINT(altivec);
#endif

#undef CPUID_PRINT
   o << "\n";
   }

void CPUID::initialize()
   {
   clear_mem(g_processor_flags, 2);

#if defined(BOTAN_TARGET_CPU_IS_PPC_FAMILY)
   if(altivec_check_sysctl() || altivec_check_pvr_emul())
      {
      g_processor_flags[0] |= CPUID_ALTIVEC_BIT;
      }
#endif

#if defined(BOTAN_TARGET_CPU_IS_X86_FAMILY)
   const u32bit INTEL_CPUID[3] = { 0x756E6547, 0x6C65746E, 0x49656E69 };
   const u32bit AMD_CPUID[3] = { 0x68747541, 0x444D4163, 0x69746E65 };

   u32bit cpuid[4] = { 0 };
   X86_CPUID(0, cpuid);

   const u32bit max_supported_sublevel = cpuid[0];

   if(max_supported_sublevel == 0)
      return;

   const bool is_intel = same_mem(cpuid + 1, INTEL_CPUID, 3);
   const bool is_amd = same_mem(cpuid + 1, AMD_CPUID, 3);

   X86_CPUID(1, cpuid);

   g_processor_flags[0] = (static_cast<u64bit>(cpuid[2]) << 32) | cpuid[3];

   if(is_intel)
      g_cache_line_size = 8 * get_byte(2, cpuid[1]);

   if(max_supported_sublevel >= 7)
      {
      clear_mem(cpuid, 4);
      X86_CPUID_SUBLEVEL(7, 0, cpuid);
      g_processor_flags[1] = (static_cast<u64bit>(cpuid[2]) << 32) | cpuid[1];
      }

   if(is_amd)
      {
      X86_CPUID(0x80000005, cpuid);
      g_cache_line_size = get_byte(3, cpuid[2]);
      }

#endif

#if defined(BOTAN_TARGET_ARCH_IS_X86_64)
   /*
   * If we don't have access to CPUID, we can still safely assume that
   * any x86-64 processor has SSE2 and RDTSC
   */
   if(g_processor_flags[0] == 0)
      g_processor_flags[0] = (1 << CPUID_SSE2_BIT) | (1 << CPUID_RDTSC_BIT);
#endif

   const uint32_t endian32 = 0x01234567;
   const uint8_t* e8 = reinterpret_cast<const uint8_t*>(&endian32);

   if(e8[0] == 0x01 && e8[1] == 0x23 && e8[2] == 0x45 && e8[3] == 0x67)
      {
      g_little_endian = false;
      }
   else if(e8[0] == 0x67 && e8[1] == 0x45 && e8[2] == 0x23 && e8[3] == 0x01)
      {
      g_little_endian = true;
      }
   else
      {
      throw Internal_Error("Unexpected endian at runtime, neither big nor little");
      }

   // If we were compiled with a known endian, verify if matches at runtime
#if defined(BOTAN_TARGET_CPU_IS_LITTLE_ENDIAN)
   BOTAN_ASSERT(g_little_endian, "Little-endian build but big-endian at runtime");
#elif defined(BOTAN_TARGET_CPU_IS_BIG_ENDIAN)
   BOTAN_ASSERT(!g_little_endian, "Big-endian build but little-endian at runtime");
#endif

   g_initialized = true;
   }

}