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 unsigned long pirq_table_addr;
  29 struct pci_bus *pci_root_bus;
  30 struct pci_raw_ops *raw_pci_ops;
  31
  32 static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *value)
  33 {
  34         return raw_pci_ops->read(0, bus->number, devfn, where, size, value);
  35 }
  36
  37 static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 value)
  38 {
  39         return raw_pci_ops->write(0, bus->number, devfn, where, size, value);
  40 }
  41
  42 struct pci_ops pci_root_ops = {
  43         .read = pci_read,
  44         .write = pci_write,
  45 };
  46
  47 /*
  48  * legacy, numa, and acpi all want to call pcibios_scan_root
  49  * from their initcalls. This flag prevents that.
  50  */
  51 int pcibios_scanned;
  52
  53 /*
  54  * This interrupt-safe spinlock protects all accesses to PCI
  55  * configuration space.
  56  */
  57 DEFINE_SPINLOCK(pci_config_lock);
  58
  59 /*
  60  * Several buggy motherboards address only 16 devices and mirror
  61  * them to next 16 IDs. We try to detect this `feature' on all
  62  * primary buses (those containing host bridges as they are
  63  * expected to be unique) and remove the ghost devices.
  64  */
  65
  66 static void __devinit pcibios_fixup_ghosts(struct pci_bus *b)
  67 {
  68         struct list_head *ln, *mn;
  69         struct pci_dev *d, *e;
  70         int mirror = PCI_DEVFN(16,0);
  71         int seen_host_bridge = 0;
  72         int i;
  73
  74         DBG("PCI: Scanning for ghost devices on bus %d\n", b->number);
  75         list_for_each(ln, &b->devices) {
  76                 d = pci_dev_b(ln);
  77                 if ((d->class >> 8) == PCI_CLASS_BRIDGE_HOST)
  78                         seen_host_bridge++;
  79                 for (mn=ln->next; mn != &b->devices; mn=mn->next) {
  80                         e = pci_dev_b(mn);
  81                         if (e->devfn != d->devfn + mirror ||
  82                             e->vendor != d->vendor ||
  83                             e->device != d->device ||
  84                             e->class != d->class)
  85                                 continue;
  86                         for(i=0; i<PCI_NUM_RESOURCES; i++)
  87                                 if (e->resource[i].start != d->resource[i].start ||
  88                                     e->resource[i].end != d->resource[i].end ||
  89                                     e->resource[i].flags != d->resource[i].flags)
  90                                         continue;
  91                         break;
  92                 }
  93                 if (mn == &b->devices)
  94                         return;
  95         }
  96         if (!seen_host_bridge)
  97                 return;
  98         printk(KERN_WARNING "PCI: Ignoring ghost devices on bus %02x\n", b->number);
  99
 100         ln = &b->devices;
 101         while (ln->next != &b->devices) {
 102                 d = pci_dev_b(ln->next);
 103                 if (d->devfn >= mirror) {
 104                         list_del(&d->global_list);
 105                         list_del(&d->bus_list);
 106                         kfree(d);
 107                 } else
 108                         ln = ln->next;
 109         }
 110 }
 111
 112 /*
 113  *  Called after each bus is probed, but before its children
 114  *  are examined.
 115  */
 116
 117 void __devinit  pcibios_fixup_bus(struct pci_bus *b)
 118 {
 119         pcibios_fixup_ghosts(b);
 120         pci_read_bridge_bases(b);
 121 }
 122
 123
 124 struct pci_bus * __devinit pcibios_scan_root(int busnum)
 125 {
 126         struct pci_bus *bus = NULL;
 127
 128         while ((bus = pci_find_next_bus(bus)) != NULL) {
 129                 if (bus->number == busnum) {
 130                         /* Already scanned */
 131                         return bus;
 132                 }
 133         }
 134
 135         printk(KERN_DEBUG "PCI: Probing PCI hardware (bus %02x)\n", busnum);
 136
 137         return pci_scan_bus_parented(NULL, busnum, &pci_root_ops, NULL);
 138 }
 139
 140 extern u8 pci_cache_line_size;
 141
 142 static int __init pcibios_init(void)
 143 {
 144         struct cpuinfo_x86 *c = &boot_cpu_data;
 145
 146         if (!raw_pci_ops) {
 147                 printk(KERN_WARNING "PCI: System does not support PCI\n");
 148                 return 0;
 149         }
 150
 151         /*
 152          * Assume PCI cacheline size of 32 bytes for all x86s except K7/K8
 153          * and P4. It's also good for 386/486s (which actually have 16)
 154          * as quite a few PCI devices do not support smaller values.
 155          */
 156         pci_cache_line_size = 32 >> 2;
 157         if (c->x86 >= 6 && c->x86_vendor == X86_VENDOR_AMD)
 158                 pci_cache_line_size = 64 >> 2;  /* K7 & K8 */
 159         else if (c->x86 > 6 && c->x86_vendor == X86_VENDOR_INTEL)
 160                 pci_cache_line_size = 128 >> 2; /* P4 */
 161
 162         pcibios_resource_survey();
 163
 164 #ifdef CONFIG_PCI_BIOS
 165         if ((pci_probe & PCI_BIOS_SORT) && !(pci_probe & PCI_NO_SORT))
 166                 pcibios_sort();
 167 #endif
 168         return 0;
 169 }
 170
 171 subsys_initcall(pcibios_init);
 172
 173 char * __devinit  pcibios_setup(char *str)
 174 {
 175         if (!strcmp(str, "off")) {
 176                 pci_probe = 0;
 177                 return NULL;
 178         }
 179 #ifdef CONFIG_PCI_BIOS
 180         else if (!strcmp(str, "bios")) {
 181                 pci_probe = PCI_PROBE_BIOS;
 182                 return NULL;
 183         } else if (!strcmp(str, "nobios")) {
 184                 pci_probe &= ~PCI_PROBE_BIOS;
 185                 return NULL;
 186         } else if (!strcmp(str, "nosort")) {
 187                 pci_probe |= PCI_NO_SORT;
 188                 return NULL;
 189         } else if (!strcmp(str, "biosirq")) {
 190                 pci_probe |= PCI_BIOS_IRQ_SCAN;
 191                 return NULL;
 192         } else if (!strncmp(str, "pirqaddr=", 9)) {
 193                 pirq_table_addr = simple_strtoul(str+9, NULL, 0);
 194                 return NULL;
 195         }
 196 #endif
 197 #ifdef CONFIG_PCI_DIRECT
 198         else if (!strcmp(str, "conf1")) {
 199                 pci_probe = PCI_PROBE_CONF1 | PCI_NO_CHECKS;
 200                 return NULL;
 201         }
 202         else if (!strcmp(str, "conf2")) {
 203                 pci_probe = PCI_PROBE_CONF2 | PCI_NO_CHECKS;
 204                 return NULL;
 205         }
 206 #endif
 207 #ifdef CONFIG_PCI_MMCONFIG
 208         else if (!strcmp(str, "nommconf")) {
 209                 pci_probe &= ~PCI_PROBE_MMCONF;
 210                 return NULL;
 211         }
 212 #endif
 213         else if (!strcmp(str, "noacpi")) {
 214                 acpi_noirq_set();
 215                 return NULL;
 216         }
 217 #ifndef CONFIG_X86_VISWS
 218         else if (!strcmp(str, "usepirqmask")) {
 219                 pci_probe |= PCI_USE_PIRQ_MASK;
 220                 return NULL;
 221         } else if (!strncmp(str, "irqmask=", 8)) {
 222                 pcibios_irq_mask = simple_strtol(str+8, NULL, 0);
 223                 return NULL;
 224         } else if (!strncmp(str, "lastbus=", 8)) {
 225                 pcibios_last_bus = simple_strtol(str+8, NULL, 0);
 226                 return NULL;
 227         }
 228 #endif
 229         else if (!strcmp(str, "rom")) {
 230                 pci_probe |= PCI_ASSIGN_ROMS;
 231                 return NULL;
 232         } else if (!strcmp(str, "assign-busses")) {
 233                 pci_probe |= PCI_ASSIGN_ALL_BUSSES;
 234                 return NULL;
 235         } else if (!strcmp(str, "routeirq")) {
 236                 pci_routeirq = 1;
 237                 return NULL;
 238         }
 239         return str;
 240 }
 241
 242 unsigned int pcibios_assign_all_busses(void)
 243 {
 244         return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
 245 }
 246
 247 int pcibios_enable_device(struct pci_dev *dev, int mask)
 248 {
 249         int err;
 250
 251         if ((err = pcibios_enable_resources(dev, mask)) < 0)
 252                 return err;
 253
 254         return pcibios_enable_irq(dev);
 255 }
 256
 257 void pcibios_disable_device (struct pci_dev *dev)
 258 {
 259         if (pcibios_disable_irq)
 260                 pcibios_disable_irq(dev);
 261 }