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 for (@ARGV) { $sse2=1 if (/-DOPENSSL_IA32_SSE2/); }
   9
  10 &function_begin("OPENSSL_ia32_cpuid");
  11         &xor    ("edx","edx");
  12         &pushf  ();
  13         &pop    ("eax");
  14         &mov    ("ecx","eax");
  15         &xor    ("eax",1<<21);
  16         &push   ("eax");
  17         &popf   ();
  18         &pushf  ();
  19         &pop    ("eax");
  20         &xor    ("ecx","eax");
  21         &bt     ("ecx",21);
  22         &jnc    (&label("nocpuid"));
  23         &mov    ("eax",1);
  24         &cpuid  ();
  25 &set_label("nocpuid");
  26         &mov    ("eax","edx");
  27         &mov    ("edx","ecx");
  28 &function_end("OPENSSL_ia32_cpuid");
  29
  30 &external_label("OPENSSL_ia32cap_P");
  31
  32 &function_begin_B("OPENSSL_rdtsc","EXTRN\t_OPENSSL_ia32cap_P:DWORD");
  33         &xor    ("eax","eax");
  34         &xor    ("edx","edx");
  35         &picmeup("ecx","OPENSSL_ia32cap_P");
  36         &bt     (&DWP(0,"ecx"),4);
  37         &jnc    (&label("notsc"));
  38         &rdtsc  ();
  39 &set_label("notsc");
  40         &ret    ();
  41 &function_end_B("OPENSSL_rdtsc");
  42
  43 # This works in Ring 0 only [read DJGPP+MS-DOS+privileged DPMI host],
  44 # but it's safe to call it on any [supported] 32-bit platform...
  45 # Just check for [non-]zero return value...
  46 &function_begin_B("OPENSSL_instrument_halt","EXTRN\t_OPENSSL_ia32cap_P:DWORD");
  47         &picmeup("ecx","OPENSSL_ia32cap_P");
  48         &bt     (&DWP(0,"ecx"),4);
  49         &jnc    (&label("nohalt"));     # no TSC
  50
  51         &data_word(0x9058900e);         # push %cs; pop %eax
  52         &and    ("eax",3);
  53         &jnz    (&label("nohalt"));     # not enough privileges
  54
  55         &pushf  ();
  56         &pop    ("eax")
  57         &bt     ("eax",9);
  58         &jnc    (&label("nohalt"));     # interrupts are disabled
  59
  60         &rdtsc  ();
  61         &push   ("edx");
  62         &push   ("eax");
  63         &halt   ();
  64         &rdtsc  ();
  65
  66         &sub    ("eax",&DWP(0,"esp"));
  67         &sbb    ("edx",&DWP(4,"esp"));
  68         &add    ("esp",8);
  69         &ret    ();
  70
  71 &set_label("nohalt");
  72         &xor    ("eax","eax");
  73         &xor    ("edx","edx");
  74         &ret    ();
  75 &function_end_B("OPENSSL_instrument_halt");
  76
  77 # Essentially there is only one use for this function. Under DJGPP:
  78 #
  79 #       #include <go32.h>
  80 #       ...
  81 #       i=OPENSSL_far_spin(_dos_ds,0x46c);
  82 #       ...
  83 # to obtain the number of spins till closest timer interrupt.
  84
  85 &function_begin_B("OPENSSL_far_spin");
  86         &pushf  ();
  87         &pop    ("eax")
  88         &bt     ("eax",9);
  89         &jnc    (&label("nospin"));     # interrupts are disabled
  90
  91         &mov    ("eax",&DWP(4,"esp"));
  92         &mov    ("ecx",&DWP(8,"esp"));
  93         &data_word (0x90d88e1e);        # push %ds, mov %eax,%ds
  94         &xor    ("eax","eax");
  95         &mov    ("edx",&DWP(0,"ecx"));
  96         &jmp    (&label("spin"));
  97
  98         &align  (16);
  99 &set_label("spin");
 100         &inc    ("eax");
 101         &cmp    ("edx",&DWP(0,"ecx"));
 102         &je     (&label("spin"));
 103
 104         &data_word (0x1f909090);        # pop   %ds
 105         &ret    ();
 106
 107 &set_label("nospin");
 108         &xor    ("eax","eax");
 109         &xor    ("edx","edx");
 110         &ret    ();
 111 &function_end_B("OPENSSL_far_spin");
 112
 113 &function_begin_B("OPENSSL_wipe_cpu","EXTRN\t_OPENSSL_ia32cap_P:DWORD");
 114         &xor    ("eax","eax");
 115         &xor    ("edx","edx");
 116         &picmeup("ecx","OPENSSL_ia32cap_P");
 117         &mov    ("ecx",&DWP(0,"ecx"));
 118         &bt     (&DWP(0,"ecx"),1);
 119         &jnc    (&label("no_x87"));
 120         if ($sse2) {
 121                 &bt     (&DWP(0,"ecx"),26);
 122                 &jnc    (&label("no_sse2"));
 123                 &pxor   ("xmm0","xmm0");
 124                 &pxor   ("xmm1","xmm1");
 125                 &pxor   ("xmm2","xmm2");
 126                 &pxor   ("xmm3","xmm3");
 127                 &pxor   ("xmm4","xmm4");
 128                 &pxor   ("xmm5","xmm5");
 129                 &pxor   ("xmm6","xmm6");
 130                 &pxor   ("xmm7","xmm7");
 131         &set_label("no_sse2");
 132         }
 133         # just a bunch of fldz to zap the fp/mm bank followed by finit...
 134         &data_word(0xeed9eed9,0xeed9eed9,0xeed9eed9,0xeed9eed9,0x90e3db9b);
 135 &set_label("no_x87");
 136         &lea    ("eax",&DWP(4,"esp"));
 137         &ret    ();
 138 &function_end_B("OPENSSL_wipe_cpu");
 139
 140 &function_begin_B("OPENSSL_atomic_add");
 141         &mov    ("edx",&DWP(4,"esp"));  # fetch the pointer, 1st arg
 142         &mov    ("ecx",&DWP(8,"esp"));  # fetch the increment, 2nd arg
 143         &push   ("ebx");
 144         &nop    ();
 145         &mov    ("eax",&DWP(0,"edx"));
 146 &set_label("spin");
 147         &lea    ("ebx",&DWP(0,"eax","ecx"));
 148         &nop    ();
 149         &data_word(0x1ab10ff0); # lock; cmpxchg %ebx,(%edx)     # %eax is envolved and is always reloaded
 150         &jne    (&label("spin"));
 151         &mov    ("eax","ebx");  # OpenSSL expects the new value
 152         &pop    ("ebx");
 153         &ret    ();
 154 &function_end_B("OPENSSL_atomic_add");
 155
 156 &initseg("OPENSSL_cpuid_setup");
 157
 158 &asm_finish();