arch/x86/pci/pcbios.c

   1 /*
   2  * BIOS32 and PCI BIOS handling.
   3  */
   4
   5 #include <linux/pci.h>
   6 #include <linux/init.h>
   7 #include <linux/slab.h>
   8 #include <linux/module.h>
   9 #include <linux/uaccess.h>
  10 #include <asm/pci_x86.h>
  11 #include <asm/pci-functions.h>
  12
  13 /* BIOS32 signature: "_32_" */
  14 #define BIOS32_SIGNATURE        (('_' << 0) + ('3' << 8) + ('2' << 16) + ('_' << 24))
  15
  16 /* PCI signature: "PCI " */
  17 #define PCI_SIGNATURE           (('P' << 0) + ('C' << 8) + ('I' << 16) + (' ' << 24))
  18
  19 /* PCI service signature: "$PCI" */
  20 #define PCI_SERVICE             (('$' << 0) + ('P' << 8) + ('C' << 16) + ('I' << 24))
  21
  22 /* PCI BIOS hardware mechanism flags */
  23 #define PCIBIOS_HW_TYPE1                0x01
  24 #define PCIBIOS_HW_TYPE2                0x02
  25 #define PCIBIOS_HW_TYPE1_SPEC           0x10
  26 #define PCIBIOS_HW_TYPE2_SPEC           0x20
  27
  28 /*
  29  * This is the standard structure used to identify the entry point
  30  * to the BIOS32 Service Directory, as documented in
  31  *      Standard BIOS 32-bit Service Directory Proposal
  32  *      Revision 0.4 May 24, 1993
  33  *      Phoenix Technologies Ltd.
  34  *      Norwood, MA
  35  * and the PCI BIOS specification.
  36  */
  37
  38 union bios32 {
  39         struct {
  40                 unsigned long signature;        /* _32_ */
  41                 unsigned long entry;            /* 32 bit physical address */
  42                 unsigned char revision;         /* Revision level, 0 */
  43                 unsigned char length;           /* Length in paragraphs should be 01 */
  44                 unsigned char checksum;         /* All bytes must add up to zero */
  45                 unsigned char reserved[5];      /* Must be zero */
  46         } fields;
  47         char chars[16];
  48 };
  49
  50 /*
  51  * Physical address of the service directory.  I don't know if we're
  52  * allowed to have more than one of these or not, so just in case
  53  * we'll make pcibios_present() take a memory start parameter and store
  54  * the array there.
  55  */
  56
  57 static struct {
  58         unsigned long address;
  59         unsigned short segment;
  60 } bios32_indirect = { 0, __KERNEL_CS };
  61
  62 /*
  63  * Returns the entry point for the given service, NULL on error
  64  */
  65
  66 static unsigned long bios32_service(unsigned long service)
  67 {
  68         unsigned char return_code;      /* %al */
  69         unsigned long address;          /* %ebx */
  70         unsigned long length;           /* %ecx */
  71         unsigned long entry;            /* %edx */
  72         unsigned long flags;
  73
  74         local_irq_save(flags);
  75         __asm__("lcall *(%%edi); cld"
  76                 : "=a" (return_code),
  77                   "=b" (address),
  78                   "=c" (length),
  79                   "=d" (entry)
  80                 : "0" (service),
  81                   "1" (0),
  82                   "D" (&bios32_indirect));
  83         local_irq_restore(flags);
  84
  85         switch (return_code) {
  86                 case 0:
  87                         return address + entry;
  88                 case 0x80:      /* Not present */
  89                         printk(KERN_WARNING "bios32_service(0x%lx): not present\n", service);
  90                         return 0;
  91                 default: /* Shouldn't happen */
  92                         printk(KERN_WARNING "bios32_service(0x%lx): returned 0x%x -- BIOS bug!\n",
  93                                 service, return_code);
  94                         return 0;
  95         }
  96 }
  97
  98 static struct {
  99         unsigned long address;
 100         unsigned short segment;
 101 } pci_indirect = { 0, __KERNEL_CS };
 102
 103 static int pci_bios_present;
 104
 105 static int __devinit check_pcibios(void)
 106 {
 107         u32 signature, eax, ebx, ecx;
 108         u8 status, major_ver, minor_ver, hw_mech;
 109         unsigned long flags, pcibios_entry;
 110
 111         if ((pcibios_entry = bios32_service(PCI_SERVICE))) {
 112                 pci_indirect.address = pcibios_entry + PAGE_OFFSET;
 113
 114                 local_irq_save(flags);
 115                 __asm__(
 116                         "lcall *(%%edi); cld\n\t"
 117                         "jc 1f\n\t"
 118                         "xor %%ah, %%ah\n"
 119                         "1:"
 120                         : "=d" (signature),
 121                           "=a" (eax),
 122                           "=b" (ebx),
 123                           "=c" (ecx)
 124                         : "1" (PCIBIOS_PCI_BIOS_PRESENT),
 125                           "D" (&pci_indirect)
 126                         : "memory");
 127                 local_irq_restore(flags);
 128
 129                 status = (eax >> 8) & 0xff;
 130                 hw_mech = eax & 0xff;
 131                 major_ver = (ebx >> 8) & 0xff;
 132                 minor_ver = ebx & 0xff;
 133                 if (pcibios_last_bus < 0)
 134                         pcibios_last_bus = ecx & 0xff;
 135                 DBG("PCI: BIOS probe returned s=%02x hw=%02x ver=%02x.%02x l=%02x\n",
 136                         status, hw_mech, major_ver, minor_ver, pcibios_last_bus);
 137                 if (status || signature != PCI_SIGNATURE) {
 138                         printk (KERN_ERR "PCI: BIOS BUG #%x[%08x] found\n",
 139                                 status, signature);
 140                         return 0;
 141                 }
 142                 printk(KERN_INFO "PCI: PCI BIOS revision %x.%02x entry at 0x%lx, last bus=%d\n",
 143                         major_ver, minor_ver, pcibios_entry, pcibios_last_bus);
 144 #ifdef CONFIG_PCI_DIRECT
 145                 if (!(hw_mech & PCIBIOS_HW_TYPE1))
 146                         pci_probe &= ~PCI_PROBE_CONF1;
 147                 if (!(hw_mech & PCIBIOS_HW_TYPE2))
 148                         pci_probe &= ~PCI_PROBE_CONF2;
 149 #endif
 150                 return 1;
 151         }
 152         return 0;
 153 }
 154
 155 static int pci_bios_read(unsigned int seg, unsigned int bus,
 156                          unsigned int devfn, int reg, int len, u32 *value)
 157 {
 158         unsigned long result = 0;
 159         unsigned long flags;
 160         unsigned long bx = (bus << 8) | devfn;
 161
 162         if (!value || (bus > 255) || (devfn > 255) || (reg > 255))
 163                 return -EINVAL;
 164
 165         spin_lock_irqsave(&pci_config_lock, flags);
 166
 167         switch (len) {
 168         case 1:
 169                 __asm__("lcall *(%%esi); cld\n\t"
 170                         "jc 1f\n\t"
 171                         "xor %%ah, %%ah\n"
 172                         "1:"
 173                         : "=c" (*value),
 174                           "=a" (result)
 175                         : "1" (PCIBIOS_READ_CONFIG_BYTE),
 176                           "b" (bx),
 177                           "D" ((long)reg),
 178                           "S" (&pci_indirect));
 179                 /*
 180                  * Zero-extend the result beyond 8 bits, do not trust the
 181                  * BIOS having done it:
 182                  */
 183                 *value &= 0xff;
 184                 break;
 185         case 2:
 186                 __asm__("lcall *(%%esi); cld\n\t"
 187                         "jc 1f\n\t"
 188                         "xor %%ah, %%ah\n"
 189                         "1:"
 190                         : "=c" (*value),
 191                           "=a" (result)
 192                         : "1" (PCIBIOS_READ_CONFIG_WORD),
 193                           "b" (bx),
 194                           "D" ((long)reg),
 195                           "S" (&pci_indirect));
 196                 /*
 197                  * Zero-extend the result beyond 16 bits, do not trust the
 198                  * BIOS having done it:
 199                  */
 200                 *value &= 0xffff;
 201                 break;
 202         case 4:
 203                 __asm__("lcall *(%%esi); cld\n\t"
 204                         "jc 1f\n\t"
 205                         "xor %%ah, %%ah\n"
 206                         "1:"
 207                         : "=c" (*value),
 208                           "=a" (result)
 209                         : "1" (PCIBIOS_READ_CONFIG_DWORD),
 210                           "b" (bx),
 211                           "D" ((long)reg),
 212                           "S" (&pci_indirect));
 213                 break;
 214         }
 215
 216         spin_unlock_irqrestore(&pci_config_lock, flags);
 217
 218         return (int)((result & 0xff00) >> 8);
 219 }
 220
 221 static int pci_bios_write(unsigned int seg, unsigned int bus,
 222                           unsigned int devfn, int reg, int len, u32 value)
 223 {
 224         unsigned long result = 0;
 225         unsigned long flags;
 226         unsigned long bx = (bus << 8) | devfn;
 227
 228         if ((bus > 255) || (devfn > 255) || (reg > 255))
 229                 return -EINVAL;
 230
 231         spin_lock_irqsave(&pci_config_lock, flags);
 232
 233         switch (len) {
 234         case 1:
 235                 __asm__("lcall *(%%esi); cld\n\t"
 236                         "jc 1f\n\t"
 237                         "xor %%ah, %%ah\n"
 238                         "1:"
 239                         : "=a" (result)
 240                         : "0" (PCIBIOS_WRITE_CONFIG_BYTE),
 241                           "c" (value),
 242                           "b" (bx),
 243                           "D" ((long)reg),
 244                           "S" (&pci_indirect));
 245                 break;
 246         case 2:
 247                 __asm__("lcall *(%%esi); cld\n\t"
 248                         "jc 1f\n\t"
 249                         "xor %%ah, %%ah\n"
 250                         "1:"
 251                         : "=a" (result)
 252                         : "0" (PCIBIOS_WRITE_CONFIG_WORD),
 253                           "c" (value),
 254                           "b" (bx),
 255                           "D" ((long)reg),
 256                           "S" (&pci_indirect));
 257                 break;
 258         case 4:
 259                 __asm__("lcall *(%%esi); cld\n\t"
 260                         "jc 1f\n\t"
 261                         "xor %%ah, %%ah\n"
 262                         "1:"
 263                         : "=a" (result)
 264                         : "0" (PCIBIOS_WRITE_CONFIG_DWORD),
 265                           "c" (value),
 266                           "b" (bx),
 267                           "D" ((long)reg),
 268                           "S" (&pci_indirect));
 269                 break;
 270         }
 271
 272         spin_unlock_irqrestore(&pci_config_lock, flags);
 273
 274         return (int)((result & 0xff00) >> 8);
 275 }
 276
 277
 278 /*
 279  * Function table for BIOS32 access
 280  */
 281
 282 static struct pci_raw_ops pci_bios_access = {
 283         .read =         pci_bios_read,
 284         .write =        pci_bios_write
 285 };
 286
 287 /*
 288  * Try to find PCI BIOS.
 289  */
 290
 291 static struct pci_raw_ops * __devinit pci_find_bios(void)
 292 {
 293         union bios32 *check;
 294         unsigned char sum;
 295         int i, length;
 296
 297         /*
 298          * Follow the standard procedure for locating the BIOS32 Service
 299          * directory by scanning the permissible address range from
 300          * 0xe0000 through 0xfffff for a valid BIOS32 structure.
 301          */
 302
 303         for (check = (union bios32 *) __va(0xe0000);
 304              check <= (union bios32 *) __va(0xffff0);
 305              ++check) {
 306                 long sig;
 307                 if (probe_kernel_address(&check->fields.signature, sig))
 308                         continue;
 309
 310                 if (check->fields.signature != BIOS32_SIGNATURE)
 311                         continue;
 312                 length = check->fields.length * 16;
 313                 if (!length)
 314                         continue;
 315                 sum = 0;
 316                 for (i = 0; i < length ; ++i)
 317                         sum += check->chars[i];
 318                 if (sum != 0)
 319                         continue;
 320                 if (check->fields.revision != 0) {
 321                         printk("PCI: unsupported BIOS32 revision %d at 0x%p\n",
 322                                 check->fields.revision, check);
 323                         continue;
 324                 }
 325                 DBG("PCI: BIOS32 Service Directory structure at 0x%p\n", check);
 326                 if (check->fields.entry >= 0x100000) {
 327                         printk("PCI: BIOS32 entry (0x%p) in high memory, "
 328                                         "cannot use.\n", check);
 329                         return NULL;
 330                 } else {
 331                         unsigned long bios32_entry = check->fields.entry;
 332                         DBG("PCI: BIOS32 Service Directory entry at 0x%lx\n",
 333                                         bios32_entry);
 334                         bios32_indirect.address = bios32_entry + PAGE_OFFSET;
 335                         if (check_pcibios())
 336                                 return &pci_bios_access;
 337                 }
 338                 break;  /* Hopefully more than one BIOS32 cannot happen... */
 339         }
 340
 341         return NULL;
 342 }
 343
 344 /*
 345  *  BIOS Functions for IRQ Routing
 346  */
 347
 348 struct irq_routing_options {
 349         u16 size;
 350         struct irq_info *table;
 351         u16 segment;
 352 } __attribute__((packed));
 353
 354 struct irq_routing_table * pcibios_get_irq_routing_table(void)
 355 {
 356         struct irq_routing_options opt;
 357         struct irq_routing_table *rt = NULL;
 358         int ret, map;
 359         unsigned long page;
 360
 361         if (!pci_bios_present)
 362                 return NULL;
 363         page = __get_free_page(GFP_KERNEL);
 364         if (!page)
 365                 return NULL;
 366         opt.table = (struct irq_info *) page;
 367         opt.size = PAGE_SIZE;
 368         opt.segment = __KERNEL_DS;
 369
 370         DBG("PCI: Fetching IRQ routing table... ");
 371         __asm__("push %%es\n\t"
 372                 "push %%ds\n\t"
 373                 "pop  %%es\n\t"
 374                 "lcall *(%%esi); cld\n\t"
 375                 "pop %%es\n\t"
 376                 "jc 1f\n\t"
 377                 "xor %%ah, %%ah\n"
 378                 "1:"
 379                 : "=a" (ret),
 380                   "=b" (map),
 381                   "=m" (opt)
 382                 : "0" (PCIBIOS_GET_ROUTING_OPTIONS),
 383                   "1" (0),
 384                   "D" ((long) &opt),
 385                   "S" (&pci_indirect),
 386                   "m" (opt)
 387                 : "memory");
 388         DBG("OK  ret=%d, size=%d, map=%x\n", ret, opt.size, map);
 389         if (ret & 0xff00)
 390                 printk(KERN_ERR "PCI: Error %02x when fetching IRQ routing table.\n", (ret >> 8) & 0xff);
 391         else if (opt.size) {
 392                 rt = kmalloc(sizeof(struct irq_routing_table) + opt.size, GFP_KERNEL);
 393                 if (rt) {
 394                         memset(rt, 0, sizeof(struct irq_routing_table));
 395                         rt->size = opt.size + sizeof(struct irq_routing_table);
 396                         rt->exclusive_irqs = map;
 397                         memcpy(rt->slots, (void *) page, opt.size);
 398                         printk(KERN_INFO "PCI: Using BIOS Interrupt Routing Table\n");
 399                 }
 400         }
 401         free_page(page);
 402         return rt;
 403 }
 404 EXPORT_SYMBOL(pcibios_get_irq_routing_table);
 405
 406 int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq)
 407 {
 408         int ret;
 409
 410         __asm__("lcall *(%%esi); cld\n\t"
 411                 "jc 1f\n\t"
 412                 "xor %%ah, %%ah\n"
 413                 "1:"
 414                 : "=a" (ret)
 415                 : "0" (PCIBIOS_SET_PCI_HW_INT),
 416                   "b" ((dev->bus->number << 8) | dev->devfn),
 417                   "c" ((irq << 8) | (pin + 10)),
 418                   "S" (&pci_indirect));
 419         return !(ret & 0xff00);
 420 }
 421 EXPORT_SYMBOL(pcibios_set_irq_routing);
 422
 423 void __init pci_pcbios_init(void)
 424 {
 425         if ((pci_probe & PCI_PROBE_BIOS)
 426                 && ((raw_pci_ops = pci_find_bios()))) {
 427                 pci_bios_present = 1;
 428         }
 429 }
 430