arch/x86/pci/early.c

   1 #include <linux/kernel.h>
   2 #include <linux/pci.h>
   3 #include <asm/pci-direct.h>
   4 #include <asm/io.h>
   5 #include "pci.h"
   6
   7 /* Direct PCI access. This is used for PCI accesses in early boot before
   8    the PCI subsystem works. */
   9
  10 #define PDprintk(x...)
  11
  12 u32 read_pci_config(u8 bus, u8 slot, u8 func, u8 offset)
  13 {
  14         u32 v;
  15         outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
  16         v = inl(0xcfc);
  17         if (v != 0xffffffff)
  18                 PDprintk("%x reading 4 from %x: %x\n", slot, offset, v);
  19         return v;
  20 }
  21
  22 u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset)
  23 {
  24         u8 v;
  25         outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
  26         v = inb(0xcfc + (offset&3));
  27         PDprintk("%x reading 1 from %x: %x\n", slot, offset, v);
  28         return v;
  29 }
  30
  31 u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset)
  32 {
  33         u16 v;
  34         outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
  35         v = inw(0xcfc + (offset&2));
  36         PDprintk("%x reading 2 from %x: %x\n", slot, offset, v);
  37         return v;
  38 }
  39
  40 void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset,
  41                                     u32 val)
  42 {
  43         PDprintk("%x writing to %x: %x\n", slot, offset, val);
  44         outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
  45         outl(val, 0xcfc);
  46 }
  47
  48 void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val)
  49 {
  50         PDprintk("%x writing to %x: %x\n", slot, offset, val);
  51         outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
  52         outb(val, 0xcfc);
  53 }
  54
  55 int early_pci_allowed(void)
  56 {
  57         return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) ==
  58                         PCI_PROBE_CONF1;
  59 }