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         &xor    ("eax","eax");
  24         &cpuid  ();
  25         &xor    ("eax","eax");
  26         &cmp    ("ebx",0x756e6547);     # "Genu"
  27         &setne  (&LB("eax"));
  28         &mov    ("ebp","eax");
  29         &cmp    ("edx",0x49656e69);     # "ineI"
  30         &setne  (&LB("eax"));
  31         &or     ("ebp","eax");
  32         &cmp    ("ecx",0x6c65746e);     # "ntel"
  33         &setne  (&LB("eax"));
  34         &or     ("ebp","eax");
  35         &mov    ("eax",1);
  36         &cpuid  ();
  37         &bt     ("edx",28);             # test hyper-threading bit
  38         &jnc    (&label("nocpuid"));
  39         &cmp    ("ebp",0);
  40         &jne    (&label("notintel"));
  41         &or     ("edx",1<<20);          # use reserved bit to engage RC4_CHAR
  42 &set_label("notintel");
  43         &shr    ("ebx",16);
  44         &cmp    (&LB("ebx"),1);         # see if cache is shared(*)
  45         &ja     (&label("nocpuid"));
  46         &and    ("edx",~(1<<28));       # clear hyper-threading bit if not
  47 &set_label("nocpuid");
  48         &mov    ("eax","edx");
  49         &mov    ("edx","ecx");
  50 &function_end("OPENSSL_ia32_cpuid");
  51 # (*)   on Core2 this value is set to 2 denoting the fact that L2
  52 #       cache is shared between cores.
  53
  54 &external_label("OPENSSL_ia32cap_P");
  55
  56 &function_begin_B("OPENSSL_rdtsc","EXTRN\t_OPENSSL_ia32cap_P:DWORD");
  57         &xor    ("eax","eax");
  58         &xor    ("edx","edx");
  59         &picmeup("ecx","OPENSSL_ia32cap_P");
  60         &bt     (&DWP(0,"ecx"),4);
  61         &jnc    (&label("notsc"));
  62         &rdtsc  ();
  63 &set_label("notsc");
  64         &ret    ();
  65 &function_end_B("OPENSSL_rdtsc");
  66
  67 # This works in Ring 0 only [read DJGPP+MS-DOS+privileged DPMI host],
  68 # but it's safe to call it on any [supported] 32-bit platform...
  69 # Just check for [non-]zero return value...
  70 &function_begin_B("OPENSSL_instrument_halt","EXTRN\t_OPENSSL_ia32cap_P:DWORD");
  71         &picmeup("ecx","OPENSSL_ia32cap_P");
  72         &bt     (&DWP(0,"ecx"),4);
  73         &jnc    (&label("nohalt"));     # no TSC
  74
  75         &data_word(0x9058900e);         # push %cs; pop %eax
  76         &and    ("eax",3);
  77         &jnz    (&label("nohalt"));     # not enough privileges
  78
  79         &pushf  ();
  80         &pop    ("eax")
  81         &bt     ("eax",9);
  82         &jnc    (&label("nohalt"));     # interrupts are disabled
  83
  84         &rdtsc  ();
  85         &push   ("edx");
  86         &push   ("eax");
  87         &halt   ();
  88         &rdtsc  ();
  89
  90         &sub    ("eax",&DWP(0,"esp"));
  91         &sbb    ("edx",&DWP(4,"esp"));
  92         &add    ("esp",8);
  93         &ret    ();
  94
  95 &set_label("nohalt");
  96         &xor    ("eax","eax");
  97         &xor    ("edx","edx");
  98         &ret    ();
  99 &function_end_B("OPENSSL_instrument_halt");
 100
 101 # Essentially there is only one use for this function. Under DJGPP:
 102 #
 103 #       #include <go32.h>
 104 #       ...
 105 #       i=OPENSSL_far_spin(_dos_ds,0x46c);
 106 #       ...
 107 # to obtain the number of spins till closest timer interrupt.
 108
 109 &function_begin_B("OPENSSL_far_spin");
 110         &pushf  ();
 111         &pop    ("eax")
 112         &bt     ("eax",9);
 113         &jnc    (&label("nospin"));     # interrupts are disabled
 114
 115         &mov    ("eax",&DWP(4,"esp"));
 116         &mov    ("ecx",&DWP(8,"esp"));
 117         &data_word (0x90d88e1e);        # push %ds, mov %eax,%ds
 118         &xor    ("eax","eax");
 119         &mov    ("edx",&DWP(0,"ecx"));
 120         &jmp    (&label("spin"));
 121
 122         &align  (16);
 123 &set_label("spin");
 124         &inc    ("eax");
 125         &cmp    ("edx",&DWP(0,"ecx"));
 126         &je     (&label("spin"));
 127
 128         &data_word (0x1f909090);        # pop   %ds
 129         &ret    ();
 130
 131 &set_label("nospin");
 132         &xor    ("eax","eax");
 133         &xor    ("edx","edx");
 134         &ret    ();
 135 &function_end_B("OPENSSL_far_spin");
 136
 137 &function_begin_B("OPENSSL_wipe_cpu","EXTRN\t_OPENSSL_ia32cap_P:DWORD");
 138         &xor    ("eax","eax");
 139         &xor    ("edx","edx");
 140         &picmeup("ecx","OPENSSL_ia32cap_P");
 141         &mov    ("ecx",&DWP(0,"ecx"));
 142         &bt     (&DWP(0,"ecx"),1);
 143         &jnc    (&label("no_x87"));
 144         if ($sse2) {
 145                 &bt     (&DWP(0,"ecx"),26);
 146                 &jnc    (&label("no_sse2"));
 147                 &pxor   ("xmm0","xmm0");
 148                 &pxor   ("xmm1","xmm1");
 149                 &pxor   ("xmm2","xmm2");
 150                 &pxor   ("xmm3","xmm3");
 151                 &pxor   ("xmm4","xmm4");
 152                 &pxor   ("xmm5","xmm5");
 153                 &pxor   ("xmm6","xmm6");
 154                 &pxor   ("xmm7","xmm7");
 155         &set_label("no_sse2");
 156         }
 157         # just a bunch of fldz to zap the fp/mm bank followed by finit...
 158         &data_word(0xeed9eed9,0xeed9eed9,0xeed9eed9,0xeed9eed9,0x90e3db9b);
 159 &set_label("no_x87");
 160         &lea    ("eax",&DWP(4,"esp"));
 161         &ret    ();
 162 &function_end_B("OPENSSL_wipe_cpu");
 163
 164 &function_begin_B("OPENSSL_atomic_add");
 165         &mov    ("edx",&DWP(4,"esp"));  # fetch the pointer, 1st arg
 166         &mov    ("ecx",&DWP(8,"esp"));  # fetch the increment, 2nd arg
 167         &push   ("ebx");
 168         &nop    ();
 169         &mov    ("eax",&DWP(0,"edx"));
 170 &set_label("spin");
 171         &lea    ("ebx",&DWP(0,"eax","ecx"));
 172         &nop    ();
 173         &data_word(0x1ab10ff0); # lock; cmpxchg %ebx,(%edx)     # %eax is envolved and is always reloaded
 174         &jne    (&label("spin"));
 175         &mov    ("eax","ebx");  # OpenSSL expects the new value
 176         &pop    ("ebx");
 177         &ret    ();
 178 &function_end_B("OPENSSL_atomic_add");
 179
 180 # This function can become handy under Win32 in situations when
 181 # we don't know which calling convention, __stdcall or __cdecl(*),
 182 # indirect callee is using. In C it can be deployed as
 183 #
 184 #ifdef OPENSSL_CPUID_OBJ
 185 #       type OPENSSL_indirect_call(void *f,...);
 186 #       ...
 187 #       OPENSSL_indirect_call(func,[up to $max arguments]);
 188 #endif
 189 #
 190 # (*)   it's designed to work even for __fastcall if number of
 191 #       arguments is 1 or 2!
 192 &function_begin_B("OPENSSL_indirect_call");
 193         {
 194         my $i,$max=7;           # $max has to be chosen as 4*n-1
 195                                 # in order to preserve eventual
 196                                 # stack alignment
 197         &push   ("ebp");
 198         &mov    ("ebp","esp");
 199         &sub    ("esp",$max*4);
 200         &mov    ("ecx",&DWP(12,"ebp"));
 201         &mov    (&DWP(0,"esp"),"ecx");
 202         &mov    ("edx",&DWP(16,"ebp"));
 203         &mov    (&DWP(4,"esp"),"edx");
 204         for($i=2;$i<$max;$i++)
 205                 {
 206                 # Some copies will be redundant/bogus...
 207                 &mov    ("eax",&DWP(12+$i*4,"ebp"));
 208                 &mov    (&DWP(0+$i*4,"esp"),"eax");
 209                 }
 210         &call_ptr       (&DWP(8,"ebp"));# make the call...
 211         &mov    ("esp","ebp");  # ... and just restore the stack pointer
 212                                 # without paying attention to what we called,
 213                                 # (__cdecl *func) or (__stdcall *one).
 214         &pop    ("ebp");
 215         &ret    ();
 216         }
 217 &function_end_B("OPENSSL_indirect_call");
 218
 219 &initseg("OPENSSL_cpuid_setup");
 220
 221 &asm_finish();