tools/power/cpupower/debug/i386/intel_gsic.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  *  (C) 2003  Bruno Ducrot
   4  *  (C) 2004  Dominik Brodowski <linux@dominikbrodowski.de>
   5  *
   6  * Based on code found in
   7  * linux/include/asm-i386/ist.h and linux/arch/i386/kernel/setup.c
   8  * and originally developed by Andy Grover <andrew.grover@intel.com>
   9  */
  10
  11 #include <stdio.h>
  12 #include <string.h>
  13 #include <lrmi.h>
  14
  15 int main (void)
  16 {
  17         struct LRMI_regs        r;
  18         int                     retval;
  19
  20         if (!LRMI_init())
  21                 return 0;
  22
  23         memset(&r, 0, sizeof(r));
  24
  25         r.eax = 0x0000E980;
  26         r.edx = 0x47534943;
  27
  28         retval = LRMI_int(0x15, &r);
  29
  30         if (!retval) {
  31                 printf("Failed!\n");
  32                 return 0;
  33         }
  34         if (r.eax == 0x47534943) {
  35                 printf("BIOS supports GSIC call:\n");
  36                 printf("\tsignature: %c%c%c%c\n",
  37                        (r.eax >> 24) & 0xff,
  38                        (r.eax >> 16) & 0xff,
  39                        (r.eax >> 8) & 0xff,
  40                        (r.eax) & 0xff);
  41                 printf("\tcommand port = 0x%.4x\n",
  42                        r.ebx & 0xffff);
  43                 printf("\tcommand =      0x%.4x\n",
  44                        (r.ebx >> 16) & 0xffff);
  45                 printf("\tevent port =   0x%.8x\n", r.ecx);
  46                 printf("\tflags =        0x%.8x\n", r.edx);
  47                 if (((r.ebx >> 16) & 0xffff) != 0x82) {
  48                         printf("non-default command value. If speedstep-smi "
  49                                "doesn't work out of the box,\nyou may want to "
  50                                "try out the default value by passing "
  51                                "smi_cmd=0x82 to the module\n ON YOUR OWN "
  52                                "RISK.\n");
  53                 }
  54                 if ((r.ebx & 0xffff) != 0xb2) {
  55                         printf("non-default command port. If speedstep-smi "
  56                                "doesn't work out of the box,\nyou may want to "
  57                                "try out the default value by passing "
  58                                "smi_port=0x82 to the module\n ON YOUR OWN "
  59                                "RISK.\n");
  60                 }
  61         } else {
  62                 printf("BIOS DOES NOT support GSIC call.  Dumping registers anyway:\n");
  63                 printf("eax = 0x%.8x\n", r.eax);
  64                 printf("ebx = 0x%.8x\n", r.ebx);
  65                 printf("ecx = 0x%.8x\n", r.ecx);
  66                 printf("edx = 0x%.8x\n", r.edx);
  67                 printf("Note also that some BIOS do not support the initial "
  68                        "GSIC call, but the newer\nspeedstep-smi driver may "
  69                        "work.\nFor this, you need to pass some arguments to "
  70                        "the speedstep-smi driver:\n");
  71                 printf("\tsmi_cmd=0x?? smi_port=0x?? smi_sig=1\n");
  72                 printf("\nUnfortunately, you have to know what exactly are "
  73                        "smi_cmd and smi_port, and this\nis system "
  74                        "dependent.\n");
  75         }
  76         return 1;
  77 }