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 <asm/pci_x86.h>
   6
   7 /* Direct PCI access. This is used for PCI accesses in early boot before
   8    the PCI subsystem works. */
   9
  10 u32 read_pci_config(u8 bus, u8 slot, u8 func, u8 offset)
  11 {
  12         u32 v;
  13         outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
  14         v = inl(0xcfc);
  15         if (v != 0xffffffff)
  16                 pr_debug("%x reading 4 from %x: %x\n", slot, offset, v);
  17         return v;
  18 }
  19
  20 u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset)
  21 {
  22         u8 v;
  23         outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
  24         v = inb(0xcfc + (offset&3));
  25         pr_debug("%x reading 1 from %x: %x\n", slot, offset, v);
  26         return v;
  27 }
  28
  29 u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset)
  30 {
  31         u16 v;
  32         outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
  33         v = inw(0xcfc + (offset&2));
  34         pr_debug("%x reading 2 from %x: %x\n", slot, offset, v);
  35         return v;
  36 }
  37
  38 void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset,
  39                                     u32 val)
  40 {
  41         pr_debug("%x writing to %x: %x\n", slot, offset, val);
  42         outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
  43         outl(val, 0xcfc);
  44 }
  45
  46 void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val)
  47 {
  48         pr_debug("%x writing to %x: %x\n", slot, offset, val);
  49         outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
  50         outb(val, 0xcfc + (offset&3));
  51 }
  52
  53 void write_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset, u16 val)
  54 {
  55         pr_debug("%x writing to %x: %x\n", slot, offset, val);
  56         outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);
  57         outw(val, 0xcfc + (offset&2));
  58 }
  59
  60 int early_pci_allowed(void)
  61 {
  62         return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) ==
  63                         PCI_PROBE_CONF1;
  64 }
  65
  66 void early_dump_pci_device(u8 bus, u8 slot, u8 func)
  67 {
  68         int i;
  69         int j;
  70         u32 val;
  71
  72         printk(KERN_INFO "pci 0000:%02x:%02x.%d config space:",
  73                bus, slot, func);
  74
  75         for (i = 0; i < 256; i += 4) {
  76                 if (!(i & 0x0f))
  77                         printk("\n  %02x:",i);
  78
  79                 val = read_pci_config(bus, slot, func, i);
  80                 for (j = 0; j < 4; j++) {
  81                         printk(" %02x", val & 0xff);
  82                         val >>= 8;
  83                 }
  84         }
  85         printk("\n");
  86 }
  87
  88 void early_dump_pci_devices(void)
  89 {
  90         unsigned bus, slot, func;
  91
  92         if (!early_pci_allowed())
  93                 return;
  94
  95         for (bus = 0; bus < 256; bus++) {
  96                 for (slot = 0; slot < 32; slot++) {
  97                         for (func = 0; func < 8; func++) {
  98                                 u32 class;
  99                                 u8 type;
 100
 101                                 class = read_pci_config(bus, slot, func,
 102                                                         PCI_CLASS_REVISION);
 103                                 if (class == 0xffffffff)
 104                                         continue;
 105
 106                                 early_dump_pci_device(bus, slot, func);
 107
 108                                 if (func == 0) {
 109                                         type = read_pci_config_byte(bus, slot,
 110                                                                     func,
 111                                                                PCI_HEADER_TYPE);
 112                                         if (!(type & 0x80))
 113                                                 break;
 114                                 }
 115                         }
 116                 }
 117         }
 118 }