crypto/x86cpuid.pl

   1 #!/usr/bin/env perl
   2
   3 push(@INC,"perlasm");
   4 require "x86asm.pl";
   5
   6 &asm_init($ARGV[0],"x86cpuid");
   7
   8 &function_begin("OPENSSL_ia32_cpuid");
   9         &xor    ("edx","edx");
  10         &pushf  ();
  11         &pop    ("eax");
  12         &mov    ("ecx","eax");
  13         &xor    ("eax",1<<21);
  14         &push   ("eax");
  15         &popf   ();
  16         &pushf  ();
  17         &pop    ("eax");
  18         &xor    ("ecx","eax");
  19         &bt     ("ecx",21);
  20         &jnc    (&label("nocpuid"));
  21         &mov    ("eax",1);
  22         &cpuid  ();
  23 &set_label("nocpuid");
  24         &mov    ("eax","edx");
  25         &mov    ("edx","ecx");
  26 &function_end("OPENSSL_ia32_cpuid");
  27
  28 &external_label("OPENSSL_ia32cap_P");
  29
  30 &function_begin_B("OPENSSL_rdtsc","EXTRN\t_OPENSSL_ia32cap_P:DWORD");
  31         &xor    ("eax","eax");
  32         &xor    ("edx","edx");
  33         &picmeup("ecx","OPENSSL_ia32cap_P");
  34         &bt     (&DWP(0,"ecx"),4);
  35         &jnc    (&label("notsc"));
  36         &rdtsc  ();
  37 &set_label("notsc");
  38         &ret    ();
  39 &function_end_B("OPENSSL_rdtsc");
  40
  41 # This works in Ring 0 only [read DJGPP+MS-DOS+privileged DPMI host],
  42 # but it's safe to call it on any [supported] 32-bit platform...
  43 # Just check for [non-]zero return value...
  44 &function_begin_B("OPENSSL_instrument_halt","EXTRN\t_OPENSSL_ia32cap_P:DWORD");
  45         &picmeup("ecx","OPENSSL_ia32cap_P");
  46         &bt     (&DWP(0,"ecx"),4);
  47         &jnc    (&label("nohalt"));     # no TSC
  48
  49         &data_word(0x9058900e);         # push %cs; pop %eax
  50         &and    ("eax",3);
  51         &jnz    (&label("nohalt"));     # not enough privileges
  52
  53         &pushf  ();
  54         &pop    ("eax")
  55         &bt     ("eax",9);
  56         &jnc    (&label("nohalt"));     # interrupts are disabled
  57
  58         &rdtsc  ();
  59         &push   ("edx");
  60         &push   ("eax");
  61         &halt   ();
  62         &rdtsc  ();
  63
  64         &sub    ("eax",&DWP(0,"esp"));
  65         &sbb    ("edx",&DWP(4,"esp"));
  66         &add    ("esp",8);
  67         &ret    ();
  68
  69 &set_label("nohalt");
  70         &xor    ("eax","eax");
  71         &xor    ("edx","edx");
  72         &ret    ();
  73 &function_end_B("OPENSSL_instrument_halt");
  74
  75 &initseg("OPENSSL_cpuid_setup");
  76
  77 &asm_finish();