arch/i386/pci/pcbios.c

   1 /*
   2  * BIOS32 and PCI BIOS handling.
   3  */
   4
   5 #include <linux/pci.h>
   6 #include <linux/init.h>
   7 #include "pci.h"
   8 #include "pci-functions.h"
   9
  10
  11 /* BIOS32 signature: "_32_" */
  12 #define BIOS32_SIGNATURE        (('_' << 0) + ('3' << 8) + ('2' << 16) + ('_' << 24))
  13
  14 /* PCI signature: "PCI " */
  15 #define PCI_SIGNATURE           (('P' << 0) + ('C' << 8) + ('I' << 16) + (' ' << 24))
  16
  17 /* PCI service signature: "$PCI" */
  18 #define PCI_SERVICE             (('$' << 0) + ('P' << 8) + ('C' << 16) + ('I' << 24))
  19
  20 /* PCI BIOS hardware mechanism flags */
  21 #define PCIBIOS_HW_TYPE1                0x01
  22 #define PCIBIOS_HW_TYPE2                0x02
  23 #define PCIBIOS_HW_TYPE1_SPEC           0x10
  24 #define PCIBIOS_HW_TYPE2_SPEC           0x20
  25
  26 /*
  27  * This is the standard structure used to identify the entry point
  28  * to the BIOS32 Service Directory, as documented in
  29  *      Standard BIOS 32-bit Service Directory Proposal
  30  *      Revision 0.4 May 24, 1993
  31  *      Phoenix Technologies Ltd.
  32  *      Norwood, MA
  33  * and the PCI BIOS specification.
  34  */
  35
  36 union bios32 {
  37         struct {
  38                 unsigned long signature;        /* _32_ */
  39                 unsigned long entry;            /* 32 bit physical address */
  40                 unsigned char revision;         /* Revision level, 0 */
  41                 unsigned char length;           /* Length in paragraphs should be 01 */
  42                 unsigned char checksum;         /* All bytes must add up to zero */
  43                 unsigned char reserved[5];      /* Must be zero */
  44         } fields;
  45         char chars[16];
  46 };
  47
  48 /*
  49  * Physical address of the service directory.  I don't know if we're
  50  * allowed to have more than one of these or not, so just in case
  51  * we'll make pcibios_present() take a memory start parameter and store
  52  * the array there.
  53  */
  54
  55 static struct {
  56         unsigned long address;
  57         unsigned short segment;
  58 } bios32_indirect = { 0, __KERNEL_CS };
  59
  60 /*
  61  * Returns the entry point for the given service, NULL on error
  62  */
  63
  64 static unsigned long bios32_service(unsigned long service)
  65 {
  66         unsigned char return_code;      /* %al */
  67         unsigned long address;          /* %ebx */
  68         unsigned long length;           /* %ecx */
  69         unsigned long entry;            /* %edx */
  70         unsigned long flags;
  71
  72         local_irq_save(flags);
  73         __asm__("lcall *(%%edi); cld"
  74                 : "=a" (return_code),
  75                   "=b" (address),
  76                   "=c" (length),
  77                   "=d" (entry)
  78                 : "0" (service),
  79                   "1" (0),
  80                   "D" (&bios32_indirect));
  81         local_irq_restore(flags);
  82
  83         switch (return_code) {
  84                 case 0:
  85                         return address + entry;
  86                 case 0x80:      /* Not present */
  87                         printk(KERN_WARNING "bios32_service(0x%lx): not present\n", service);
  88                         return 0;
  89                 default: /* Shouldn't happen */
  90                         printk(KERN_WARNING "bios32_service(0x%lx): returned 0x%x -- BIOS bug!\n",
  91                                 service, return_code);
  92                         return 0;
  93         }
  94 }
  95
  96 static struct {
  97         unsigned long address;
  98         unsigned short segment;
  99 } pci_indirect = { 0, __KERNEL_CS };
 100
 101 static int pci_bios_present;
 102
 103 static int __devinit check_pcibios(void)
 104 {
 105         u32 signature, eax, ebx, ecx;
 106         u8 status, major_ver, minor_ver, hw_mech;
 107         unsigned long flags, pcibios_entry;
 108
 109         if ((pcibios_entry = bios32_service(PCI_SERVICE))) {
 110                 pci_indirect.address = pcibios_entry + PAGE_OFFSET;
 111
 112                 local_irq_save(flags);
 113                 __asm__(
 114                         "lcall *(%%edi); cld\n\t"
 115                         "jc 1f\n\t"
 116                         "xor %%ah, %%ah\n"
 117                         "1:"
 118                         : "=d" (signature),
 119                           "=a" (eax),
 120                           "=b" (ebx),
 121                           "=c" (ecx)
 122                         : "1" (PCIBIOS_PCI_BIOS_PRESENT),
 123                           "D" (&pci_indirect)
 124                         : "memory");
 125                 local_irq_restore(flags);
 126
 127                 status = (eax >> 8) & 0xff;
 128                 hw_mech = eax & 0xff;
 129                 major_ver = (ebx >> 8) & 0xff;
 130                 minor_ver = ebx & 0xff;
 131                 if (pcibios_last_bus < 0)
 132                         pcibios_last_bus = ecx & 0xff;
 133                 DBG("PCI: BIOS probe returned s=%02x hw=%02x ver=%02x.%02x l=%02x\n",
 134                         status, hw_mech, major_ver, minor_ver, pcibios_last_bus);
 135                 if (status || signature != PCI_SIGNATURE) {
 136                         printk (KERN_ERR "PCI: BIOS BUG #%x[%08x] found\n",
 137                                 status, signature);
 138                         return 0;
 139                 }
 140                 printk(KERN_INFO "PCI: PCI BIOS revision %x.%02x entry at 0x%lx, last bus=%d\n",
 141                         major_ver, minor_ver, pcibios_entry, pcibios_last_bus);
 142 #ifdef CONFIG_PCI_DIRECT
 143                 if (!(hw_mech & PCIBIOS_HW_TYPE1))
 144                         pci_probe &= ~PCI_PROBE_CONF1;
 145                 if (!(hw_mech & PCIBIOS_HW_TYPE2))
 146                         pci_probe &= ~PCI_PROBE_CONF2;
 147 #endif
 148                 return 1;
 149         }
 150         return 0;
 151 }
 152
 153 static int __devinit pci_bios_find_device (unsigned short vendor, unsigned short device_id,
 154                                         unsigned short index, unsigned char *bus, unsigned char *device_fn)
 155 {
 156         unsigned short bx;
 157         unsigned short ret;
 158
 159         __asm__("lcall *(%%edi); cld\n\t"
 160                 "jc 1f\n\t"
 161                 "xor %%ah, %%ah\n"
 162                 "1:"
 163                 : "=b" (bx),
 164                   "=a" (ret)
 165                 : "1" (PCIBIOS_FIND_PCI_DEVICE),
 166                   "c" (device_id),
 167                   "d" (vendor),
 168                   "S" ((int) index),
 169                   "D" (&pci_indirect));
 170         *bus = (bx >> 8) & 0xff;
 171         *device_fn = bx & 0xff;
 172         return (int) (ret & 0xff00) >> 8;
 173 }
 174
 175 static int pci_bios_read(unsigned int seg, unsigned int bus,
 176                          unsigned int devfn, int reg, int len, u32 *value)
 177 {
 178         unsigned long result = 0;
 179         unsigned long flags;
 180         unsigned long bx = (bus << 8) | devfn;
 181
 182         if (!value || (bus > 255) || (devfn > 255) || (reg > 255))
 183                 return -EINVAL;
 184
 185         spin_lock_irqsave(&pci_config_lock, flags);
 186
 187         switch (len) {
 188         case 1:
 189                 __asm__("lcall *(%%esi); cld\n\t"
 190                         "jc 1f\n\t"
 191                         "xor %%ah, %%ah\n"
 192                         "1:"
 193                         : "=c" (*value),
 194                           "=a" (result)
 195                         : "1" (PCIBIOS_READ_CONFIG_BYTE),
 196                           "b" (bx),
 197                           "D" ((long)reg),
 198                           "S" (&pci_indirect));
 199                 break;
 200         case 2:
 201                 __asm__("lcall *(%%esi); cld\n\t"
 202                         "jc 1f\n\t"
 203                         "xor %%ah, %%ah\n"
 204                         "1:"
 205                         : "=c" (*value),
 206                           "=a" (result)
 207                         : "1" (PCIBIOS_READ_CONFIG_WORD),
 208                           "b" (bx),
 209                           "D" ((long)reg),
 210                           "S" (&pci_indirect));
 211                 break;
 212         case 4:
 213                 __asm__("lcall *(%%esi); cld\n\t"
 214                         "jc 1f\n\t"
 215                         "xor %%ah, %%ah\n"
 216                         "1:"
 217                         : "=c" (*value),
 218                           "=a" (result)
 219                         : "1" (PCIBIOS_READ_CONFIG_DWORD),
 220                           "b" (bx),
 221                           "D" ((long)reg),
 222                           "S" (&pci_indirect));
 223                 break;
 224         }
 225
 226         spin_unlock_irqrestore(&pci_config_lock, flags);
 227
 228         return (int)((result & 0xff00) >> 8);
 229 }
 230
 231 static int pci_bios_write(unsigned int seg, unsigned int bus,
 232                           unsigned int devfn, int reg, int len, u32 value)
 233 {
 234         unsigned long result = 0;
 235         unsigned long flags;
 236         unsigned long bx = (bus << 8) | devfn;
 237
 238         if ((bus > 255) || (devfn > 255) || (reg > 255))
 239                 return -EINVAL;
 240
 241         spin_lock_irqsave(&pci_config_lock, flags);
 242
 243         switch (len) {
 244         case 1:
 245                 __asm__("lcall *(%%esi); cld\n\t"
 246                         "jc 1f\n\t"
 247                         "xor %%ah, %%ah\n"
 248                         "1:"
 249                         : "=a" (result)
 250                         : "0" (PCIBIOS_WRITE_CONFIG_BYTE),
 251                           "c" (value),
 252                           "b" (bx),
 253                           "D" ((long)reg),
 254                           "S" (&pci_indirect));
 255                 break;
 256         case 2:
 257                 __asm__("lcall *(%%esi); cld\n\t"
 258                         "jc 1f\n\t"
 259                         "xor %%ah, %%ah\n"
 260                         "1:"
 261                         : "=a" (result)
 262                         : "0" (PCIBIOS_WRITE_CONFIG_WORD),
 263                           "c" (value),
 264                           "b" (bx),
 265                           "D" ((long)reg),
 266                           "S" (&pci_indirect));
 267                 break;
 268         case 4:
 269                 __asm__("lcall *(%%esi); cld\n\t"
 270                         "jc 1f\n\t"
 271                         "xor %%ah, %%ah\n"
 272                         "1:"
 273                         : "=a" (result)
 274                         : "0" (PCIBIOS_WRITE_CONFIG_DWORD),
 275                           "c" (value),
 276                           "b" (bx),
 277                           "D" ((long)reg),
 278                           "S" (&pci_indirect));
 279                 break;
 280         }
 281
 282         spin_unlock_irqrestore(&pci_config_lock, flags);
 283
 284         return (int)((result & 0xff00) >> 8);
 285 }
 286
 287
 288 /*
 289  * Function table for BIOS32 access
 290  */
 291
 292 static struct pci_raw_ops pci_bios_access = {
 293         .read =         pci_bios_read,
 294         .write =        pci_bios_write
 295 };
 296
 297 /*
 298  * Try to find PCI BIOS.
 299  */
 300
 301 static struct pci_raw_ops * __devinit pci_find_bios(void)
 302 {
 303         union bios32 *check;
 304         unsigned char sum;
 305         int i, length;
 306
 307         /*
 308          * Follow the standard procedure for locating the BIOS32 Service
 309          * directory by scanning the permissible address range from
 310          * 0xe0000 through 0xfffff for a valid BIOS32 structure.
 311          */
 312
 313         for (check = (union bios32 *) __va(0xe0000);
 314              check <= (union bios32 *) __va(0xffff0);
 315              ++check) {
 316                 if (check->fields.signature != BIOS32_SIGNATURE)
 317                         continue;
 318                 length = check->fields.length * 16;
 319                 if (!length)
 320                         continue;
 321                 sum = 0;
 322                 for (i = 0; i < length ; ++i)
 323                         sum += check->chars[i];
 324                 if (sum != 0)
 325                         continue;
 326                 if (check->fields.revision != 0) {
 327                         printk("PCI: unsupported BIOS32 revision %d at 0x%p\n",
 328                                 check->fields.revision, check);
 329                         continue;
 330                 }
 331                 DBG("PCI: BIOS32 Service Directory structure at 0x%p\n", check);
 332                 if (check->fields.entry >= 0x100000) {
 333                         printk("PCI: BIOS32 entry (0x%p) in high memory, cannot use.\n", check);
 334                         return NULL;
 335                 } else {
 336                         unsigned long bios32_entry = check->fields.entry;
 337                         DBG("PCI: BIOS32 Service Directory entry at 0x%lx\n", bios32_entry);
 338                         bios32_indirect.address = bios32_entry + PAGE_OFFSET;
 339                         if (check_pcibios())
 340                                 return &pci_bios_access;
 341                 }
 342                 break;  /* Hopefully more than one BIOS32 cannot happen... */
 343         }
 344
 345         return NULL;
 346 }
 347
 348 /*
 349  * Sort the device list according to PCI BIOS. Nasty hack, but since some
 350  * fool forgot to define the `correct' device order in the PCI BIOS specs
 351  * and we want to be (possibly bug-to-bug ;-]) compatible with older kernels
 352  * which used BIOS ordering, we are bound to do this...
 353  */
 354
 355 void __devinit pcibios_sort(void)
 356 {
 357         LIST_HEAD(sorted_devices);
 358         struct list_head *ln;
 359         struct pci_dev *dev, *d;
 360         int idx, found;
 361         unsigned char bus, devfn;
 362
 363         DBG("PCI: Sorting device list...\n");
 364         while (!list_empty(&pci_devices)) {
 365                 ln = pci_devices.next;
 366                 dev = pci_dev_g(ln);
 367                 idx = found = 0;
 368                 while (pci_bios_find_device(dev->vendor, dev->device, idx, &bus, &devfn) == PCIBIOS_SUCCESSFUL) {
 369                         idx++;
 370                         list_for_each(ln, &pci_devices) {
 371                                 d = pci_dev_g(ln);
 372                                 if (d->bus->number == bus && d->devfn == devfn) {
 373                                         list_del(&d->global_list);
 374                                         list_add_tail(&d->global_list, &sorted_devices);
 375                                         if (d == dev)
 376                                                 found = 1;
 377                                         break;
 378                                 }
 379                         }
 380                         if (ln == &pci_devices) {
 381                                 printk(KERN_WARNING "PCI: BIOS reporting unknown device %02x:%02x\n", bus, devfn);
 382                                 /*
 383                                  * We must not continue scanning as several buggy BIOSes
 384                                  * return garbage after the last device. Grr.
 385                                  */
 386                                 break;
 387                         }
 388                 }
 389                 if (!found) {
 390                         printk(KERN_WARNING "PCI: Device %s not found by BIOS\n",
 391                                 pci_name(dev));
 392                         list_del(&dev->global_list);
 393                         list_add_tail(&dev->global_list, &sorted_devices);
 394                 }
 395         }
 396         list_splice(&sorted_devices, &pci_devices);
 397 }
 398
 399 /*
 400  *  BIOS Functions for IRQ Routing
 401  */
 402
 403 struct irq_routing_options {
 404         u16 size;
 405         struct irq_info *table;
 406         u16 segment;
 407 } __attribute__((packed));
 408
 409 struct irq_routing_table * __devinit pcibios_get_irq_routing_table(void)
 410 {
 411         struct irq_routing_options opt;
 412         struct irq_routing_table *rt = NULL;
 413         int ret, map;
 414         unsigned long page;
 415
 416         if (!pci_bios_present)
 417                 return NULL;
 418         page = __get_free_page(GFP_KERNEL);
 419         if (!page)
 420                 return NULL;
 421         opt.table = (struct irq_info *) page;
 422         opt.size = PAGE_SIZE;
 423         opt.segment = __KERNEL_DS;
 424
 425         DBG("PCI: Fetching IRQ routing table... ");
 426         __asm__("push %%es\n\t"
 427                 "push %%ds\n\t"
 428                 "pop  %%es\n\t"
 429                 "lcall *(%%esi); cld\n\t"
 430                 "pop %%es\n\t"
 431                 "jc 1f\n\t"
 432                 "xor %%ah, %%ah\n"
 433                 "1:"
 434                 : "=a" (ret),
 435                   "=b" (map),
 436                   "=m" (opt)
 437                 : "0" (PCIBIOS_GET_ROUTING_OPTIONS),
 438                   "1" (0),
 439                   "D" ((long) &opt),
 440                   "S" (&pci_indirect),
 441                   "m" (opt)
 442                 : "memory");
 443         DBG("OK  ret=%d, size=%d, map=%x\n", ret, opt.size, map);
 444         if (ret & 0xff00)
 445                 printk(KERN_ERR "PCI: Error %02x when fetching IRQ routing table.\n", (ret >> 8) & 0xff);
 446         else if (opt.size) {
 447                 rt = kmalloc(sizeof(struct irq_routing_table) + opt.size, GFP_KERNEL);
 448                 if (rt) {
 449                         memset(rt, 0, sizeof(struct irq_routing_table));
 450                         rt->size = opt.size + sizeof(struct irq_routing_table);
 451                         rt->exclusive_irqs = map;
 452                         memcpy(rt->slots, (void *) page, opt.size);
 453                         printk(KERN_INFO "PCI: Using BIOS Interrupt Routing Table\n");
 454                 }
 455         }
 456         free_page(page);
 457         return rt;
 458 }
 459
 460
 461 int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq)
 462 {
 463         int ret;
 464
 465         __asm__("lcall *(%%esi); cld\n\t"
 466                 "jc 1f\n\t"
 467                 "xor %%ah, %%ah\n"
 468                 "1:"
 469                 : "=a" (ret)
 470                 : "0" (PCIBIOS_SET_PCI_HW_INT),
 471                   "b" ((dev->bus->number << 8) | dev->devfn),
 472                   "c" ((irq << 8) | (pin + 10)),
 473                   "S" (&pci_indirect));
 474         return !(ret & 0xff00);
 475 }
 476
 477 static int __init pci_pcbios_init(void)
 478 {
 479         if ((pci_probe & PCI_PROBE_BIOS)
 480                 && ((raw_pci_ops = pci_find_bios()))) {
 481                 pci_probe |= PCI_BIOS_SORT;
 482                 pci_bios_present = 1;
 483         }
 484         return 0;
 485 }
 486
 487 arch_initcall(pci_pcbios_init);