bus/pci.c

   1 /* pci.c - Generic PCI interfaces.  */
   2 /*
   3  *  GRUB  --  GRand Unified Bootloader
   4  *  Copyright (C) 2007  Free Software Foundation, Inc.
   5  *
   6  *  GRUB is free software: you can redistribute it and/or modify
   7  *  it under the terms of the GNU General Public License as published by
   8  *  the Free Software Foundation, either version 3 of the License, or
   9  *  (at your option) any later version.
  10  *
  11  *  GRUB is distributed in the hope that it will be useful,
  12  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  *  GNU General Public License for more details.
  15  *
  16  *  You should have received a copy of the GNU General Public License
  17  *  along with GRUB.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 #include <grub/dl.h>
  21 #include <grub/pci.h>
  22
  23 grub_pci_address_t
  24 grub_pci_make_address (int bus, int device, int function, int reg)
  25 {
  26   return (1 << 31) | (bus << 16) | (device << 11) | (function << 8) | (reg << 2);
  27 }
  28
  29 void
  30 grub_pci_iterate (grub_pci_iteratefunc_t hook)
  31 {
  32   int bus;
  33   int dev;
  34   int func;
  35   grub_pci_address_t addr;
  36   grub_pci_id_t id;
  37   grub_uint32_t hdr;
  38
  39   for (bus = 0; bus < 256; bus++)
  40     {
  41       for (dev = 0; dev < 32; dev++)
  42         {
  43           for (func = 0; func < 8; func++)
  44             {
  45               addr = grub_pci_make_address (bus, dev, func, 0);
  46               id = grub_pci_read (addr);
  47
  48               /* Check if there is a device present.  */
  49               if (id >> 16 == 0xFFFF)
  50                 continue;
  51
  52               if (hook (bus, dev, func, id))
  53                 return;
  54
  55               /* Probe only func = 0 if the device if not multifunction */
  56               if (func == 0)
  57                 {
  58                   addr = grub_pci_make_address (bus, dev, func, 3);
  59                   hdr = grub_pci_read (addr);
  60                   if (!(hdr & 0x800000))
  61                     break;
  62                 }
  63             }
  64         }
  65     }
  66 }