arch/i386/pci/common.c

   1 /*
   2  *      Low-Level PCI Support for PC
   3  *
   4  *      (c) 1999--2000 Martin Mares <mj@ucw.cz>
   5  */
   6
   7 #include <linux/sched.h>
   8 #include <linux/pci.h>
   9 #include <linux/ioport.h>
  10 #include <linux/init.h>
  11
  12 #include <asm/acpi.h>
  13 #include <asm/segment.h>
  14 #include <asm/io.h>
  15 #include <asm/smp.h>
  16
  17 #include "pci.h"
  18
  19 #ifdef CONFIG_PCI_BIOS
  20 extern  void pcibios_sort(void);
  21 #endif
  22
  23 unsigned int pci_probe = PCI_PROBE_BIOS | PCI_PROBE_CONF1 | PCI_PROBE_CONF2 |
  24                                 PCI_PROBE_MMCONF;
  25
  26 int pci_routeirq;
  27 int pcibios_last_bus = -1;
  28 struct pci_bus *pci_root_bus = NULL;
  29 struct pci_raw_ops *raw_pci_ops;
  30
  31 static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
  32 {
  33         return raw_pci_ops->read(0, bus->number, devfn, where, size, value);
  34 }
  35
  36 static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 value)
  37 {
  38         return raw_pci_ops->write(0, bus->number, devfn, where, size, value);
  39 }
  40
  41 struct pci_ops pci_root_ops = {
  42         .read = pci_read,
  43         .write = pci_write,
  44 };
  45
  46 /*
  47  * legacy, numa, and acpi all want to call pcibios_scan_root
  48  * from their initcalls. This flag prevents that.
  49  */
  50 int pcibios_scanned;
  51
  52 /*
  53  * This interrupt-safe spinlock protects all accesses to PCI
  54  * configuration space.
  55  */
  56 DEFINE_SPINLOCK(pci_config_lock);
  57
  58 /*
  59  * Several buggy motherboards address only 16 devices and mirror
  60  * them to next 16 IDs. We try to detect this `feature' on all
  61  * primary buses (those containing host bridges as they are
  62  * expected to be unique) and remove the ghost devices.
  63  */
  64
  65 static void __devinit pcibios_fixup_ghosts(struct pci_bus *b)
  66 {
  67         struct list_head *ln, *mn;
  68         struct pci_dev *d, *e;
  69         int mirror = PCI_DEVFN(16,0);
  70         int seen_host_bridge = 0;
  71         int i;
  72
  73         DBG("PCI: Scanning for ghost devices on bus %d\n", b->number);
  74         list_for_each(ln, &b->devices) {
  75                 d = pci_dev_b(ln);
  76                 if ((d->class >> 8) == PCI_CLASS_BRIDGE_HOST)
  77                         seen_host_bridge++;
  78                 for (mn=ln->next; mn != &b->devices; mn=mn->next) {
  79                         e = pci_dev_b(mn);
  80                         if (e->devfn != d->devfn + mirror ||
  81                             e->vendor != d->vendor ||
  82                             e->device != d->device ||
  83                             e->class != d->class)
  84                                 continue;
  85                         for(i=0; i<PCI_NUM_RESOURCES; i++)
  86                                 if (e->resource[i].start != d->resource[i].start ||
  87                                     e->resource[i].end != d->resource[i].end ||
  88                                     e->resource[i].flags != d->resource[i].flags)
  89                                         continue;
  90                         break;
  91                 }
  92                 if (mn == &b->devices)
  93                         return;
  94         }
  95         if (!seen_host_bridge)
  96                 return;
  97         printk(KERN_WARNING "PCI: Ignoring ghost devices on bus %02x\n", b->number);
  98
  99         ln = &b->devices;
 100         while (ln->next != &b->devices) {
 101                 d = pci_dev_b(ln->next);
 102                 if (d->devfn >= mirror) {
 103                         list_del(&d->global_list);
 104                         list_del(&d->bus_list);
 105                         kfree(d);
 106                 } else
 107                         ln = ln->next;
 108         }
 109 }
 110
 111 /*
 112  *  Called after each bus is probed, but before its children
 113  *  are examined.
 114  */
 115
 116 void __devinit  pcibios_fixup_bus(struct pci_bus *b)
 117 {
 118         pcibios_fixup_ghosts(b);
 119         pci_read_bridge_bases(b);
 120 }
 121
 122
 123 struct pci_bus * __devinit pcibios_scan_root(int busnum)
 124 {
 125         struct pci_bus *bus = NULL;
 126
 127         while ((bus = pci_find_next_bus(bus)) != NULL) {
 128                 if (bus->number == busnum) {
 129                         /* Already scanned */
 130                         return bus;
 131                 }
 132         }
 133
 134         printk("PCI: Probing PCI hardware (bus %02x)\n", busnum);
 135
 136         return pci_scan_bus(busnum, &pci_root_ops, NULL);
 137 }
 138
 139 extern u8 pci_cache_line_size;
 140
 141 static int __init pcibios_init(void)
 142 {
 143         struct cpuinfo_x86 *c = &boot_cpu_data;
 144
 145         if (!raw_pci_ops) {
 146                 printk("PCI: System does not support PCI\n");
 147                 return 0;
 148         }
 149
 150         /*
 151          * Assume PCI cacheline size of 32 bytes for all x86s except K7/K8
 152          * and P4. It's also good for 386/486s (which actually have 16)
 153          * as quite a few PCI devices do not support smaller values.
 154          */
 155         pci_cache_line_size = 32 >> 2;
 156         if (c->x86 >= 6 && c->x86_vendor == X86_VENDOR_AMD)
 157                 pci_cache_line_size = 64 >> 2;  /* K7 & K8 */
 158         else if (c->x86 > 6 && c->x86_vendor == X86_VENDOR_INTEL)
 159                 pci_cache_line_size = 128 >> 2; /* P4 */
 160
 161         pcibios_resource_survey();
 162
 163 #ifdef CONFIG_PCI_BIOS
 164         if ((pci_probe & PCI_BIOS_SORT) && !(pci_probe & PCI_NO_SORT))
 165                 pcibios_sort();
 166 #endif
 167         return 0;
 168 }
 169
 170 subsys_initcall(pcibios_init);
 171
 172 char * __devinit  pcibios_setup(char *str)
 173 {
 174         if (!strcmp(str, "off")) {
 175                 pci_probe = 0;
 176                 return NULL;
 177         }
 178 #ifdef CONFIG_PCI_BIOS
 179         else if (!strcmp(str, "bios")) {
 180                 pci_probe = PCI_PROBE_BIOS;
 181                 return NULL;
 182         } else if (!strcmp(str, "nobios")) {
 183                 pci_probe &= ~PCI_PROBE_BIOS;
 184                 return NULL;
 185         } else if (!strcmp(str, "nosort")) {
 186                 pci_probe |= PCI_NO_SORT;
 187                 return NULL;
 188         } else if (!strcmp(str, "biosirq")) {
 189                 pci_probe |= PCI_BIOS_IRQ_SCAN;
 190                 return NULL;
 191         }
 192 #endif
 193 #ifdef CONFIG_PCI_DIRECT
 194         else if (!strcmp(str, "conf1")) {
 195                 pci_probe = PCI_PROBE_CONF1 | PCI_NO_CHECKS;
 196                 return NULL;
 197         }
 198         else if (!strcmp(str, "conf2")) {
 199                 pci_probe = PCI_PROBE_CONF2 | PCI_NO_CHECKS;
 200                 return NULL;
 201         }
 202 #endif
 203 #ifdef CONFIG_PCI_MMCONFIG
 204         else if (!strcmp(str, "nommconf")) {
 205                 pci_probe &= ~PCI_PROBE_MMCONF;
 206                 return NULL;
 207         }
 208 #endif
 209         else if (!strcmp(str, "noacpi")) {
 210                 acpi_noirq_set();
 211                 return NULL;
 212         }
 213 #ifndef CONFIG_X86_VISWS
 214         else if (!strcmp(str, "usepirqmask")) {
 215                 pci_probe |= PCI_USE_PIRQ_MASK;
 216                 return NULL;
 217         } else if (!strncmp(str, "irqmask=", 8)) {
 218                 pcibios_irq_mask = simple_strtol(str+8, NULL, 0);
 219                 return NULL;
 220         } else if (!strncmp(str, "lastbus=", 8)) {
 221                 pcibios_last_bus = simple_strtol(str+8, NULL, 0);
 222                 return NULL;
 223         }
 224 #endif
 225         else if (!strcmp(str, "rom")) {
 226                 pci_probe |= PCI_ASSIGN_ROMS;
 227                 return NULL;
 228         } else if (!strcmp(str, "assign-busses")) {
 229                 pci_probe |= PCI_ASSIGN_ALL_BUSSES;
 230                 return NULL;
 231         } else if (!strcmp(str, "routeirq")) {
 232                 pci_routeirq = 1;
 233                 return NULL;
 234         }
 235         return str;
 236 }
 237
 238 unsigned int pcibios_assign_all_busses(void)
 239 {
 240         return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
 241 }
 242
 243 int pcibios_enable_device(struct pci_dev *dev, int mask)
 244 {
 245         int err;
 246
 247         if ((err = pcibios_enable_resources(dev, mask)) < 0)
 248                 return err;
 249
 250         return pcibios_enable_irq(dev);
 251 }