arch/x86/kernel/mpparse.c

   1 /*
   2  *      Intel Multiprocessor Specification 1.1 and 1.4
   3  *      compliant MP-table parsing routines.
   4  *
   5  *      (c) 1995 Alan Cox, Building #3 <alan@lxorguk.ukuu.org.uk>
   6  *      (c) 1998, 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
   7  *      (c) 2008 Alexey Starikovskiy <astarikovskiy@suse.de>
   8  */
   9
  10 #include <linux/mm.h>
  11 #include <linux/init.h>
  12 #include <linux/delay.h>
  13 #include <linux/bootmem.h>
  14 #include <linux/kernel_stat.h>
  15 #include <linux/mc146818rtc.h>
  16 #include <linux/bitops.h>
  17 #include <linux/acpi.h>
  18 #include <linux/module.h>
  19 #include <linux/smp.h>
  20 #include <linux/pci.h>
  21
  22 #include <asm/mtrr.h>
  23 #include <asm/mpspec.h>
  24 #include <asm/pgalloc.h>
  25 #include <asm/io_apic.h>
  26 #include <asm/proto.h>
  27 #include <asm/bios_ebda.h>
  28 #include <asm/e820.h>
  29 #include <asm/trampoline.h>
  30 #include <asm/setup.h>
  31 #include <asm/smp.h>
  32
  33 #include <asm/apic.h>
  34 /*
  35  * Checksum an MP configuration block.
  36  */
  37
  38 static int __init mpf_checksum(unsigned char *mp, int len)
  39 {
  40         int sum = 0;
  41
  42         while (len--)
  43                 sum += *mp++;
  44
  45         return sum & 0xFF;
  46 }
  47
  48 static void __init MP_processor_info(struct mpc_cpu *m)
  49 {
  50         int apicid;
  51         char *bootup_cpu = "";
  52
  53         if (!(m->cpuflag & CPU_ENABLED)) {
  54                 disabled_cpus++;
  55                 return;
  56         }
  57
  58         if (x86_quirks->mpc_apic_id)
  59                 apicid = x86_quirks->mpc_apic_id(m);
  60         else
  61                 apicid = m->apicid;
  62
  63         if (m->cpuflag & CPU_BOOTPROCESSOR) {
  64                 bootup_cpu = " (Bootup-CPU)";
  65                 boot_cpu_physical_apicid = m->apicid;
  66         }
  67
  68         printk(KERN_INFO "Processor #%d%s\n", m->apicid, bootup_cpu);
  69         generic_processor_info(apicid, m->apicver);
  70 }
  71
  72 #ifdef CONFIG_X86_IO_APIC
  73 static void __init MP_bus_info(struct mpc_bus *m)
  74 {
  75         char str[7];
  76         memcpy(str, m->bustype, 6);
  77         str[6] = 0;
  78
  79         if (x86_quirks->mpc_oem_bus_info)
  80                 x86_quirks->mpc_oem_bus_info(m, str);
  81         else
  82                 apic_printk(APIC_VERBOSE, "Bus #%d is %s\n", m->busid, str);
  83
  84 #if MAX_MP_BUSSES < 256
  85         if (m->busid >= MAX_MP_BUSSES) {
  86                 printk(KERN_WARNING "MP table busid value (%d) for bustype %s "
  87                        " is too large, max. supported is %d\n",
  88                        m->busid, str, MAX_MP_BUSSES - 1);
  89                 return;
  90         }
  91 #endif
  92
  93         if (strncmp(str, BUSTYPE_ISA, sizeof(BUSTYPE_ISA) - 1) == 0) {
  94                 set_bit(m->busid, mp_bus_not_pci);
  95 #if defined(CONFIG_EISA) || defined(CONFIG_MCA)
  96                 mp_bus_id_to_type[m->busid] = MP_BUS_ISA;
  97 #endif
  98         } else if (strncmp(str, BUSTYPE_PCI, sizeof(BUSTYPE_PCI) - 1) == 0) {
  99                 if (x86_quirks->mpc_oem_pci_bus)
 100                         x86_quirks->mpc_oem_pci_bus(m);
 101
 102                 clear_bit(m->busid, mp_bus_not_pci);
 103 #if defined(CONFIG_EISA) || defined(CONFIG_MCA)
 104                 mp_bus_id_to_type[m->busid] = MP_BUS_PCI;
 105         } else if (strncmp(str, BUSTYPE_EISA, sizeof(BUSTYPE_EISA) - 1) == 0) {
 106                 mp_bus_id_to_type[m->busid] = MP_BUS_EISA;
 107         } else if (strncmp(str, BUSTYPE_MCA, sizeof(BUSTYPE_MCA) - 1) == 0) {
 108                 mp_bus_id_to_type[m->busid] = MP_BUS_MCA;
 109 #endif
 110         } else
 111                 printk(KERN_WARNING "Unknown bustype %s - ignoring\n", str);
 112 }
 113
 114 static int bad_ioapic(unsigned long address)
 115 {
 116         if (nr_ioapics >= MAX_IO_APICS) {
 117                 printk(KERN_ERR "ERROR: Max # of I/O APICs (%d) exceeded "
 118                        "(found %d)\n", MAX_IO_APICS, nr_ioapics);
 119                 panic("Recompile kernel with bigger MAX_IO_APICS!\n");
 120         }
 121         if (!address) {
 122                 printk(KERN_ERR "WARNING: Bogus (zero) I/O APIC address"
 123                        " found in table, skipping!\n");
 124                 return 1;
 125         }
 126         return 0;
 127 }
 128
 129 static void __init MP_ioapic_info(struct mpc_ioapic *m)
 130 {
 131         if (!(m->flags & MPC_APIC_USABLE))
 132                 return;
 133
 134         printk(KERN_INFO "I/O APIC #%d Version %d at 0x%X.\n",
 135                m->apicid, m->apicver, m->apicaddr);
 136
 137         if (bad_ioapic(m->apicaddr))
 138                 return;
 139
 140         mp_ioapics[nr_ioapics].apicaddr = m->apicaddr;
 141         mp_ioapics[nr_ioapics].apicid = m->apicid;
 142         mp_ioapics[nr_ioapics].type = m->type;
 143         mp_ioapics[nr_ioapics].apicver = m->apicver;
 144         mp_ioapics[nr_ioapics].flags = m->flags;
 145         nr_ioapics++;
 146 }
 147
 148 static void print_MP_intsrc_info(struct mpc_intsrc *m)
 149 {
 150         apic_printk(APIC_VERBOSE, "Int: type %d, pol %d, trig %d, bus %02x,"
 151                 " IRQ %02x, APIC ID %x, APIC INT %02x\n",
 152                 m->irqtype, m->irqflag & 3, (m->irqflag >> 2) & 3, m->srcbus,
 153                 m->srcbusirq, m->dstapic, m->dstirq);
 154 }
 155
 156 static void __init print_mp_irq_info(struct mpc_intsrc *mp_irq)
 157 {
 158         apic_printk(APIC_VERBOSE, "Int: type %d, pol %d, trig %d, bus %02x,"
 159                 " IRQ %02x, APIC ID %x, APIC INT %02x\n",
 160                 mp_irq->irqtype, mp_irq->irqflag & 3,
 161                 (mp_irq->irqflag >> 2) & 3, mp_irq->srcbus,
 162                 mp_irq->srcbusirq, mp_irq->dstapic, mp_irq->dstirq);
 163 }
 164
 165 static void __init assign_to_mp_irq(struct mpc_intsrc *m,
 166                                     struct mpc_intsrc *mp_irq)
 167 {
 168         mp_irq->dstapic = m->dstapic;
 169         mp_irq->type = m->type;
 170         mp_irq->irqtype = m->irqtype;
 171         mp_irq->irqflag = m->irqflag;
 172         mp_irq->srcbus = m->srcbus;
 173         mp_irq->srcbusirq = m->srcbusirq;
 174         mp_irq->dstirq = m->dstirq;
 175 }
 176
 177 static void __init assign_to_mpc_intsrc(struct mpc_intsrc *mp_irq,
 178                                         struct mpc_intsrc *m)
 179 {
 180         m->dstapic = mp_irq->dstapic;
 181         m->type = mp_irq->type;
 182         m->irqtype = mp_irq->irqtype;
 183         m->irqflag = mp_irq->irqflag;
 184         m->srcbus = mp_irq->srcbus;
 185         m->srcbusirq = mp_irq->srcbusirq;
 186         m->dstirq = mp_irq->dstirq;
 187 }
 188
 189 static int __init mp_irq_mpc_intsrc_cmp(struct mpc_intsrc *mp_irq,
 190                                         struct mpc_intsrc *m)
 191 {
 192         if (mp_irq->dstapic != m->dstapic)
 193                 return 1;
 194         if (mp_irq->type != m->type)
 195                 return 2;
 196         if (mp_irq->irqtype != m->irqtype)
 197                 return 3;
 198         if (mp_irq->irqflag != m->irqflag)
 199                 return 4;
 200         if (mp_irq->srcbus != m->srcbus)
 201                 return 5;
 202         if (mp_irq->srcbusirq != m->srcbusirq)
 203                 return 6;
 204         if (mp_irq->dstirq != m->dstirq)
 205                 return 7;
 206
 207         return 0;
 208 }
 209
 210 static void __init MP_intsrc_info(struct mpc_intsrc *m)
 211 {
 212         int i;
 213
 214         print_MP_intsrc_info(m);
 215
 216         for (i = 0; i < mp_irq_entries; i++) {
 217                 if (!mp_irq_mpc_intsrc_cmp(&mp_irqs[i], m))
 218                         return;
 219         }
 220
 221         assign_to_mp_irq(m, &mp_irqs[mp_irq_entries]);
 222         if (++mp_irq_entries == MAX_IRQ_SOURCES)
 223                 panic("Max # of irq sources exceeded!!\n");
 224 }
 225 #else /* CONFIG_X86_IO_APIC */
 226 static inline void __init MP_bus_info(struct mpc_bus *m) {}
 227 static inline void __init MP_ioapic_info(struct mpc_ioapic *m) {}
 228 static inline void __init MP_intsrc_info(struct mpc_intsrc *m) {}
 229 #endif /* CONFIG_X86_IO_APIC */
 230
 231
 232 static void __init MP_lintsrc_info(struct mpc_lintsrc *m)
 233 {
 234         apic_printk(APIC_VERBOSE, "Lint: type %d, pol %d, trig %d, bus %02x,"
 235                 " IRQ %02x, APIC ID %x, APIC LINT %02x\n",
 236                 m->irqtype, m->irqflag & 3, (m->irqflag >> 2) & 3, m->srcbusid,
 237                 m->srcbusirq, m->destapic, m->destapiclint);
 238 }
 239
 240 /*
 241  * Read/parse the MPC
 242  */
 243
 244 static int __init smp_check_mpc(struct mpc_table *mpc, char *oem, char *str)
 245 {
 246
 247         if (memcmp(mpc->signature, MPC_SIGNATURE, 4)) {
 248                 printk(KERN_ERR "MPTABLE: bad signature [%c%c%c%c]!\n",
 249                        mpc->signature[0], mpc->signature[1],
 250                        mpc->signature[2], mpc->signature[3]);
 251                 return 0;
 252         }
 253         if (mpf_checksum((unsigned char *)mpc, mpc->length)) {
 254                 printk(KERN_ERR "MPTABLE: checksum error!\n");
 255                 return 0;
 256         }
 257         if (mpc->spec != 0x01 && mpc->spec != 0x04) {
 258                 printk(KERN_ERR "MPTABLE: bad table version (%d)!!\n",
 259                        mpc->spec);
 260                 return 0;
 261         }
 262         if (!mpc->lapic) {
 263                 printk(KERN_ERR "MPTABLE: null local APIC address!\n");
 264                 return 0;
 265         }
 266         memcpy(oem, mpc->oem, 8);
 267         oem[8] = 0;
 268         printk(KERN_INFO "MPTABLE: OEM ID: %s\n", oem);
 269
 270         memcpy(str, mpc->productid, 12);
 271         str[12] = 0;
 272
 273         printk(KERN_INFO "MPTABLE: Product ID: %s\n", str);
 274
 275         printk(KERN_INFO "MPTABLE: APIC at: 0x%X\n", mpc->lapic);
 276
 277         return 1;
 278 }
 279
 280 static void skip_entry(unsigned char **ptr, int *count, int size)
 281 {
 282         *ptr += size;
 283         *count += size;
 284 }
 285
 286 static void __init smp_dump_mptable(struct mpc_table *mpc, unsigned char *mpt)
 287 {
 288         printk(KERN_ERR "Your mptable is wrong, contact your HW vendor!\n"
 289                 "type %x\n", *mpt);
 290         print_hex_dump(KERN_ERR, "  ", DUMP_PREFIX_ADDRESS, 16,
 291                         1, mpc, mpc->length, 1);
 292 }
 293
 294 static int __init smp_read_mpc(struct mpc_table *mpc, unsigned early)
 295 {
 296         char str[16];
 297         char oem[10];
 298
 299         int count = sizeof(*mpc);
 300         unsigned char *mpt = ((unsigned char *)mpc) + count;
 301
 302         if (!smp_check_mpc(mpc, oem, str))
 303                 return 0;
 304
 305 #ifdef CONFIG_X86_32
 306         generic_mps_oem_check(mpc, oem, str);
 307 #endif
 308         /* save the local APIC address, it might be non-default */
 309         if (!acpi_lapic)
 310                 mp_lapic_addr = mpc->lapic;
 311
 312         if (early)
 313                 return 1;
 314
 315         if (mpc->oemptr && x86_quirks->smp_read_mpc_oem) {
 316                 struct mpc_oemtable *oem_table = (void *)(long)mpc->oemptr;
 317                 x86_quirks->smp_read_mpc_oem(oem_table, mpc->oemsize);
 318         }
 319
 320         /*
 321          *      Now process the configuration blocks.
 322          */
 323         if (x86_quirks->mpc_record)
 324                 *x86_quirks->mpc_record = 0;
 325
 326         while (count < mpc->length) {
 327                 switch (*mpt) {
 328                 case MP_PROCESSOR:
 329                         /* ACPI may have already provided this data */
 330                         if (!acpi_lapic)
 331                                 MP_processor_info((struct mpc_cpu *)mpt);
 332                         skip_entry(&mpt, &count, sizeof(struct mpc_cpu));
 333                         break;
 334                 case MP_BUS:
 335                         MP_bus_info((struct mpc_bus *)mpt);
 336                         skip_entry(&mpt, &count, sizeof(struct mpc_bus));
 337                         break;
 338                 case MP_IOAPIC:
 339                         MP_ioapic_info((struct mpc_ioapic *)mpt);
 340                         skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
 341                         break;
 342                 case MP_INTSRC:
 343                         MP_intsrc_info((struct mpc_intsrc *)mpt);
 344                         skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
 345                         break;
 346                 case MP_LINTSRC:
 347                         MP_lintsrc_info((struct mpc_lintsrc *)mpt);
 348                         skip_entry(&mpt, &count, sizeof(struct mpc_lintsrc));
 349                         break;
 350                 default:
 351                         /* wrong mptable */
 352                         smp_dump_mptable(mpc, mpt);
 353                         count = mpc->length;
 354                         break;
 355                 }
 356                 if (x86_quirks->mpc_record)
 357                         (*x86_quirks->mpc_record)++;
 358         }
 359
 360 #ifdef CONFIG_X86_BIGSMP
 361         generic_bigsmp_probe();
 362 #endif
 363
 364         if (apic->setup_apic_routing)
 365                 apic->setup_apic_routing();
 366
 367         if (!num_processors)
 368                 printk(KERN_ERR "MPTABLE: no processors registered!\n");
 369         return num_processors;
 370 }
 371
 372 #ifdef CONFIG_X86_IO_APIC
 373
 374 static int __init ELCR_trigger(unsigned int irq)
 375 {
 376         unsigned int port;
 377
 378         port = 0x4d0 + (irq >> 3);
 379         return (inb(port) >> (irq & 7)) & 1;
 380 }
 381
 382 static void __init construct_default_ioirq_mptable(int mpc_default_type)
 383 {
 384         struct mpc_intsrc intsrc;
 385         int i;
 386         int ELCR_fallback = 0;
 387
 388         intsrc.type = MP_INTSRC;
 389         intsrc.irqflag = 0;     /* conforming */
 390         intsrc.srcbus = 0;
 391         intsrc.dstapic = mp_ioapics[0].apicid;
 392
 393         intsrc.irqtype = mp_INT;
 394
 395         /*
 396          *  If true, we have an ISA/PCI system with no IRQ entries
 397          *  in the MP table. To prevent the PCI interrupts from being set up
 398          *  incorrectly, we try to use the ELCR. The sanity check to see if
 399          *  there is good ELCR data is very simple - IRQ0, 1, 2 and 13 can
 400          *  never be level sensitive, so we simply see if the ELCR agrees.
 401          *  If it does, we assume it's valid.
 402          */
 403         if (mpc_default_type == 5) {
 404                 printk(KERN_INFO "ISA/PCI bus type with no IRQ information... "
 405                        "falling back to ELCR\n");
 406
 407                 if (ELCR_trigger(0) || ELCR_trigger(1) || ELCR_trigger(2) ||
 408                     ELCR_trigger(13))
 409                         printk(KERN_ERR "ELCR contains invalid data... "
 410                                "not using ELCR\n");
 411                 else {
 412                         printk(KERN_INFO
 413                                "Using ELCR to identify PCI interrupts\n");
 414                         ELCR_fallback = 1;
 415                 }
 416         }
 417
 418         for (i = 0; i < 16; i++) {
 419                 switch (mpc_default_type) {
 420                 case 2:
 421                         if (i == 0 || i == 13)
 422                                 continue;       /* IRQ0 & IRQ13 not connected */
 423                         /* fall through */
 424                 default:
 425                         if (i == 2)
 426                                 continue;       /* IRQ2 is never connected */
 427                 }
 428
 429                 if (ELCR_fallback) {
 430                         /*
 431                          *  If the ELCR indicates a level-sensitive interrupt, we
 432                          *  copy that information over to the MP table in the
 433                          *  irqflag field (level sensitive, active high polarity).
 434                          */
 435                         if (ELCR_trigger(i))
 436                                 intsrc.irqflag = 13;
 437                         else
 438                                 intsrc.irqflag = 0;
 439                 }
 440
 441                 intsrc.srcbusirq = i;
 442                 intsrc.dstirq = i ? i : 2;      /* IRQ0 to INTIN2 */
 443                 MP_intsrc_info(&intsrc);
 444         }
 445
 446         intsrc.irqtype = mp_ExtINT;
 447         intsrc.srcbusirq = 0;
 448         intsrc.dstirq = 0;      /* 8259A to INTIN0 */
 449         MP_intsrc_info(&intsrc);
 450 }
 451
 452
 453 static void __init construct_ioapic_table(int mpc_default_type)
 454 {
 455         struct mpc_ioapic ioapic;
 456         struct mpc_bus bus;
 457
 458         bus.type = MP_BUS;
 459         bus.busid = 0;
 460         switch (mpc_default_type) {
 461         default:
 462                 printk(KERN_ERR "???\nUnknown standard configuration %d\n",
 463                        mpc_default_type);
 464                 /* fall through */
 465         case 1:
 466         case 5:
 467                 memcpy(bus.bustype, "ISA   ", 6);
 468                 break;
 469         case 2:
 470         case 6:
 471         case 3:
 472                 memcpy(bus.bustype, "EISA  ", 6);
 473                 break;
 474         case 4:
 475         case 7:
 476                 memcpy(bus.bustype, "MCA   ", 6);
 477         }
 478         MP_bus_info(&bus);
 479         if (mpc_default_type > 4) {
 480                 bus.busid = 1;
 481                 memcpy(bus.bustype, "PCI   ", 6);
 482                 MP_bus_info(&bus);
 483         }
 484
 485         ioapic.type = MP_IOAPIC;
 486         ioapic.apicid = 2;
 487         ioapic.apicver = mpc_default_type > 4 ? 0x10 : 0x01;
 488         ioapic.flags = MPC_APIC_USABLE;
 489         ioapic.apicaddr = 0xFEC00000;
 490         MP_ioapic_info(&ioapic);
 491
 492         /*
 493          * We set up most of the low 16 IO-APIC pins according to MPS rules.
 494          */
 495         construct_default_ioirq_mptable(mpc_default_type);
 496 }
 497 #else
 498 static inline void __init construct_ioapic_table(int mpc_default_type) { }
 499 #endif
 500
 501 static inline void __init construct_default_ISA_mptable(int mpc_default_type)
 502 {
 503         struct mpc_cpu processor;
 504         struct mpc_lintsrc lintsrc;
 505         int linttypes[2] = { mp_ExtINT, mp_NMI };
 506         int i;
 507
 508         /*
 509          * local APIC has default address
 510          */
 511         mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
 512
 513         /*
 514          * 2 CPUs, numbered 0 & 1.
 515          */
 516         processor.type = MP_PROCESSOR;
 517         /* Either an integrated APIC or a discrete 82489DX. */
 518         processor.apicver = mpc_default_type > 4 ? 0x10 : 0x01;
 519         processor.cpuflag = CPU_ENABLED;
 520         processor.cpufeature = (boot_cpu_data.x86 << 8) |
 521             (boot_cpu_data.x86_model << 4) | boot_cpu_data.x86_mask;
 522         processor.featureflag = boot_cpu_data.x86_capability[0];
 523         processor.reserved[0] = 0;
 524         processor.reserved[1] = 0;
 525         for (i = 0; i < 2; i++) {
 526                 processor.apicid = i;
 527                 MP_processor_info(&processor);
 528         }
 529
 530         construct_ioapic_table(mpc_default_type);
 531
 532         lintsrc.type = MP_LINTSRC;
 533         lintsrc.irqflag = 0;            /* conforming */
 534         lintsrc.srcbusid = 0;
 535         lintsrc.srcbusirq = 0;
 536         lintsrc.destapic = MP_APIC_ALL;
 537         for (i = 0; i < 2; i++) {
 538                 lintsrc.irqtype = linttypes[i];
 539                 lintsrc.destapiclint = i;
 540                 MP_lintsrc_info(&lintsrc);
 541         }
 542 }
 543
 544 static struct mpf_intel *mpf_found;
 545
 546 static unsigned long __init get_mpc_size(unsigned long physptr)
 547 {
 548         struct mpc_table *mpc;
 549         unsigned long size;
 550
 551         mpc = early_ioremap(physptr, PAGE_SIZE);
 552         size = mpc->length;
 553         early_iounmap(mpc, PAGE_SIZE);
 554         apic_printk(APIC_VERBOSE, "  mpc: %lx-%lx\n", physptr, physptr + size);
 555
 556         return size;
 557 }
 558
 559 static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
 560 {
 561         struct mpc_table *mpc;
 562         unsigned long size;
 563
 564         size = get_mpc_size(mpf->physptr);
 565         mpc = early_ioremap(mpf->physptr, size);
 566         /*
 567          * Read the physical hardware table.  Anything here will
 568          * override the defaults.
 569          */
 570         if (!smp_read_mpc(mpc, early)) {
 571 #ifdef CONFIG_X86_LOCAL_APIC
 572                 smp_found_config = 0;
 573 #endif
 574                 printk(KERN_ERR "BIOS bug, MP table errors detected!...\n"
 575                         "... disabling SMP support. (tell your hw vendor)\n");
 576                 early_iounmap(mpc, size);
 577                 return -1;
 578         }
 579         early_iounmap(mpc, size);
 580
 581         if (early)
 582                 return -1;
 583
 584 #ifdef CONFIG_X86_IO_APIC
 585         /*
 586          * If there are no explicit MP IRQ entries, then we are
 587          * broken.  We set up most of the low 16 IO-APIC pins to
 588          * ISA defaults and hope it will work.
 589          */
 590         if (!mp_irq_entries) {
 591                 struct mpc_bus bus;
 592
 593                 printk(KERN_ERR "BIOS bug, no explicit IRQ entries, "
 594                        "using default mptable. (tell your hw vendor)\n");
 595
 596                 bus.type = MP_BUS;
 597                 bus.busid = 0;
 598                 memcpy(bus.bustype, "ISA   ", 6);
 599                 MP_bus_info(&bus);
 600
 601                 construct_default_ioirq_mptable(0);
 602         }
 603 #endif
 604
 605         return 0;
 606 }
 607
 608 /*
 609  * Scan the memory blocks for an SMP configuration block.
 610  */
 611 static void __init __get_smp_config(unsigned int early)
 612 {
 613         struct mpf_intel *mpf = mpf_found;
 614
 615         if (!mpf)
 616                 return;
 617
 618         if (acpi_lapic && early)
 619                 return;
 620
 621         /*
 622          * MPS doesn't support hyperthreading, aka only have
 623          * thread 0 apic id in MPS table
 624          */
 625         if (acpi_lapic && acpi_ioapic)
 626                 return;
 627
 628         if (x86_quirks->mach_get_smp_config) {
 629                 if (x86_quirks->mach_get_smp_config(early))
 630                         return;
 631         }
 632
 633         printk(KERN_INFO "Intel MultiProcessor Specification v1.%d\n",
 634                mpf->specification);
 635 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)
 636         if (mpf->feature2 & (1 << 7)) {
 637                 printk(KERN_INFO "    IMCR and PIC compatibility mode.\n");
 638                 pic_mode = 1;
 639         } else {
 640                 printk(KERN_INFO "    Virtual Wire compatibility mode.\n");
 641                 pic_mode = 0;
 642         }
 643 #endif
 644         /*
 645          * Now see if we need to read further.
 646          */
 647         if (mpf->feature1 != 0) {
 648                 if (early) {
 649                         /*
 650                          * local APIC has default address
 651                          */
 652                         mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
 653                         return;
 654                 }
 655
 656                 printk(KERN_INFO "Default MP configuration #%d\n",
 657                        mpf->feature1);
 658                 construct_default_ISA_mptable(mpf->feature1);
 659
 660         } else if (mpf->physptr) {
 661                 if (check_physptr(mpf, early))
 662                         return;
 663         } else
 664                 BUG();
 665
 666         if (!early)
 667                 printk(KERN_INFO "Processors: %d\n", num_processors);
 668         /*
 669          * Only use the first configuration found.
 670          */
 671 }
 672
 673 void __init early_get_smp_config(void)
 674 {
 675         __get_smp_config(1);
 676 }
 677
 678 void __init get_smp_config(void)
 679 {
 680         __get_smp_config(0);
 681 }
 682
 683 static void __init smp_reserve_bootmem(struct mpf_intel *mpf)
 684 {
 685         unsigned long size = get_mpc_size(mpf->physptr);
 686 #ifdef CONFIG_X86_32
 687         /*
 688          * We cannot access to MPC table to compute table size yet,
 689          * as only few megabytes from the bottom is mapped now.
 690          * PC-9800's MPC table places on the very last of physical
 691          * memory; so that simply reserving PAGE_SIZE from mpf->physptr
 692          * yields BUG() in reserve_bootmem.
 693          * also need to make sure physptr is below than max_low_pfn
 694          * we don't need reserve the area above max_low_pfn
 695          */
 696         unsigned long end = max_low_pfn * PAGE_SIZE;
 697
 698         if (mpf->physptr < end) {
 699                 if (mpf->physptr + size > end)
 700                         size = end - mpf->physptr;
 701                 reserve_bootmem_generic(mpf->physptr, size, BOOTMEM_DEFAULT);
 702         }
 703 #else
 704         reserve_bootmem_generic(mpf->physptr, size, BOOTMEM_DEFAULT);
 705 #endif
 706 }
 707
 708 static int __init smp_scan_config(unsigned long base, unsigned long length,
 709                                   unsigned reserve)
 710 {
 711         unsigned int *bp = phys_to_virt(base);
 712         struct mpf_intel *mpf;
 713
 714         apic_printk(APIC_VERBOSE, "Scan SMP from %p for %ld bytes.\n",
 715                         bp, length);
 716         BUILD_BUG_ON(sizeof(*mpf) != 16);
 717
 718         while (length > 0) {
 719                 mpf = (struct mpf_intel *)bp;
 720                 if ((*bp == SMP_MAGIC_IDENT) &&
 721                     (mpf->length == 1) &&
 722                     !mpf_checksum((unsigned char *)bp, 16) &&
 723                     ((mpf->specification == 1)
 724                      || (mpf->specification == 4))) {
 725 #ifdef CONFIG_X86_LOCAL_APIC
 726                         smp_found_config = 1;
 727 #endif
 728                         mpf_found = mpf;
 729
 730                         printk(KERN_INFO "found SMP MP-table at [%p] %llx\n",
 731                                mpf, (u64)virt_to_phys(mpf));
 732
 733                         if (!reserve)
 734                                 return 1;
 735                         reserve_bootmem_generic(virt_to_phys(mpf), sizeof(*mpf),
 736                                                 BOOTMEM_DEFAULT);
 737                         if (mpf->physptr)
 738                                 smp_reserve_bootmem(mpf);
 739
 740                         return 1;
 741                 }
 742                 bp += 4;
 743                 length -= 16;
 744         }
 745         return 0;
 746 }
 747
 748 static void __init __find_smp_config(unsigned int reserve)
 749 {
 750         unsigned int address;
 751
 752         if (x86_quirks->mach_find_smp_config) {
 753                 if (x86_quirks->mach_find_smp_config(reserve))
 754                         return;
 755         }
 756         /*
 757          * FIXME: Linux assumes you have 640K of base ram..
 758          * this continues the error...
 759          *
 760          * 1) Scan the bottom 1K for a signature
 761          * 2) Scan the top 1K of base RAM
 762          * 3) Scan the 64K of bios
 763          */
 764         if (smp_scan_config(0x0, 0x400, reserve) ||
 765             smp_scan_config(639 * 0x400, 0x400, reserve) ||
 766             smp_scan_config(0xF0000, 0x10000, reserve))
 767                 return;
 768         /*
 769          * If it is an SMP machine we should know now, unless the
 770          * configuration is in an EISA/MCA bus machine with an
 771          * extended bios data area.
 772          *
 773          * there is a real-mode segmented pointer pointing to the
 774          * 4K EBDA area at 0x40E, calculate and scan it here.
 775          *
 776          * NOTE! There are Linux loaders that will corrupt the EBDA
 777          * area, and as such this kind of SMP config may be less
 778          * trustworthy, simply because the SMP table may have been
 779          * stomped on during early boot. These loaders are buggy and
 780          * should be fixed.
 781          *
 782          * MP1.4 SPEC states to only scan first 1K of 4K EBDA.
 783          */
 784
 785         address = get_bios_ebda();
 786         if (address)
 787                 smp_scan_config(address, 0x400, reserve);
 788 }
 789
 790 void __init early_find_smp_config(void)
 791 {
 792         __find_smp_config(0);
 793 }
 794
 795 void __init find_smp_config(void)
 796 {
 797         __find_smp_config(1);
 798 }
 799
 800 #ifdef CONFIG_X86_IO_APIC
 801 static u8 __initdata irq_used[MAX_IRQ_SOURCES];
 802
 803 static int  __init get_MP_intsrc_index(struct mpc_intsrc *m)
 804 {
 805         int i;
 806
 807         if (m->irqtype != mp_INT)
 808                 return 0;
 809
 810         if (m->irqflag != 0x0f)
 811                 return 0;
 812
 813         /* not legacy */
 814
 815         for (i = 0; i < mp_irq_entries; i++) {
 816                 if (mp_irqs[i].irqtype != mp_INT)
 817                         continue;
 818
 819                 if (mp_irqs[i].irqflag != 0x0f)
 820                         continue;
 821
 822                 if (mp_irqs[i].srcbus != m->srcbus)
 823                         continue;
 824                 if (mp_irqs[i].srcbusirq != m->srcbusirq)
 825                         continue;
 826                 if (irq_used[i]) {
 827                         /* already claimed */
 828                         return -2;
 829                 }
 830                 irq_used[i] = 1;
 831                 return i;
 832         }
 833
 834         /* not found */
 835         return -1;
 836 }
 837
 838 #define SPARE_SLOT_NUM 20
 839
 840 static struct mpc_intsrc __initdata *m_spare[SPARE_SLOT_NUM];
 841
 842 static void __init check_irq_src(struct mpc_intsrc *m, int *nr_m_spare)
 843 {
 844         int i;
 845
 846         apic_printk(APIC_VERBOSE, "OLD ");
 847         print_MP_intsrc_info(m);
 848
 849         i = get_MP_intsrc_index(m);
 850         if (i > 0) {
 851                 assign_to_mpc_intsrc(&mp_irqs[i], m);
 852                 apic_printk(APIC_VERBOSE, "NEW ");
 853                 print_mp_irq_info(&mp_irqs[i]);
 854                 return;
 855         }
 856         if (!i) {
 857                 /* legacy, do nothing */
 858                 return;
 859         }
 860         if (*nr_m_spare < SPARE_SLOT_NUM) {
 861                 /*
 862                  * not found (-1), or duplicated (-2) are invalid entries,
 863                  * we need to use the slot later
 864                  */
 865                 m_spare[*nr_m_spare] = m;
 866                 *nr_m_spare += 1;
 867         }
 868 }
 869 #else /* CONFIG_X86_IO_APIC */
 870 static
 871 inline void __init check_irq_src(struct mpc_intsrc *m, int *nr_m_spare) {}
 872 #endif /* CONFIG_X86_IO_APIC */
 873
 874 static int
 875 check_slot(unsigned long mpc_new_phys, unsigned long mpc_new_length, int count)
 876 {
 877         int ret = 0;
 878
 879         if (!mpc_new_phys || count <= mpc_new_length) {
 880                 WARN(1, "update_mptable: No spare slots (length: %x)\n", count);
 881                 return -1;
 882         }
 883
 884         return ret;
 885 }
 886
 887 static int  __init replace_intsrc_all(struct mpc_table *mpc,
 888                                         unsigned long mpc_new_phys,
 889                                         unsigned long mpc_new_length)
 890 {
 891 #ifdef CONFIG_X86_IO_APIC
 892         int i;
 893 #endif
 894         int count = sizeof(*mpc);
 895         int nr_m_spare = 0;
 896         unsigned char *mpt = ((unsigned char *)mpc) + count;
 897
 898         printk(KERN_INFO "mpc_length %x\n", mpc->length);
 899         while (count < mpc->length) {
 900                 switch (*mpt) {
 901                 case MP_PROCESSOR:
 902                         skip_entry(&mpt, &count, sizeof(struct mpc_cpu));
 903                         break;
 904                 case MP_BUS:
 905                         skip_entry(&mpt, &count, sizeof(struct mpc_bus));
 906                         break;
 907                 case MP_IOAPIC:
 908                         skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
 909                         break;
 910                 case MP_INTSRC:
 911                         check_irq_src((struct mpc_intsrc *)mpt, &nr_m_spare);
 912                         skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
 913                         break;
 914                 case MP_LINTSRC:
 915                         skip_entry(&mpt, &count, sizeof(struct mpc_lintsrc));
 916                         break;
 917                 default:
 918                         /* wrong mptable */
 919                         smp_dump_mptable(mpc, mpt);
 920                         goto out;
 921                 }
 922         }
 923
 924 #ifdef CONFIG_X86_IO_APIC
 925         for (i = 0; i < mp_irq_entries; i++) {
 926                 if (irq_used[i])
 927                         continue;
 928
 929                 if (mp_irqs[i].irqtype != mp_INT)
 930                         continue;
 931
 932                 if (mp_irqs[i].irqflag != 0x0f)
 933                         continue;
 934
 935                 if (nr_m_spare > 0) {
 936                         apic_printk(APIC_VERBOSE, "*NEW* found\n");
 937                         nr_m_spare--;
 938                         assign_to_mpc_intsrc(&mp_irqs[i], m_spare[nr_m_spare]);
 939                         m_spare[nr_m_spare] = NULL;
 940                 } else {
 941                         struct mpc_intsrc *m = (struct mpc_intsrc *)mpt;
 942                         count += sizeof(struct mpc_intsrc);
 943                         if (check_slot(mpc_new_phys, mpc_new_length, count) < 0)
 944                                 goto out;
 945                         assign_to_mpc_intsrc(&mp_irqs[i], m);
 946                         mpc->length = count;
 947                         mpt += sizeof(struct mpc_intsrc);
 948                 }
 949                 print_mp_irq_info(&mp_irqs[i]);
 950         }
 951 #endif
 952 out:
 953         /* update checksum */
 954         mpc->checksum = 0;
 955         mpc->checksum -= mpf_checksum((unsigned char *)mpc, mpc->length);
 956
 957         return 0;
 958 }
 959
 960 int enable_update_mptable;
 961
 962 static int __init update_mptable_setup(char *str)
 963 {
 964         enable_update_mptable = 1;
 965 #ifdef CONFIG_PCI
 966         pci_routeirq = 1;
 967 #endif
 968         return 0;
 969 }
 970 early_param("update_mptable", update_mptable_setup);
 971
 972 static unsigned long __initdata mpc_new_phys;
 973 static unsigned long mpc_new_length __initdata = 4096;
 974
 975 /* alloc_mptable or alloc_mptable=4k */
 976 static int __initdata alloc_mptable;
 977 static int __init parse_alloc_mptable_opt(char *p)
 978 {
 979         enable_update_mptable = 1;
 980 #ifdef CONFIG_PCI
 981         pci_routeirq = 1;
 982 #endif
 983         alloc_mptable = 1;
 984         if (!p)
 985                 return 0;
 986         mpc_new_length = memparse(p, &p);
 987         return 0;
 988 }
 989 early_param("alloc_mptable", parse_alloc_mptable_opt);
 990
 991 void __init early_reserve_e820_mpc_new(void)
 992 {
 993         if (enable_update_mptable && alloc_mptable) {
 994                 u64 startt = 0;
 995 #ifdef CONFIG_X86_TRAMPOLINE
 996                 startt = TRAMPOLINE_BASE;
 997 #endif
 998                 mpc_new_phys = early_reserve_e820(startt, mpc_new_length, 4);
 999         }
1000 }
1001
1002 static int __init update_mp_table(void)
1003 {
1004         char str[16];
1005         char oem[10];
1006         struct mpf_intel *mpf;
1007         struct mpc_table *mpc, *mpc_new;
1008
1009         if (!enable_update_mptable)
1010                 return 0;
1011
1012         mpf = mpf_found;
1013         if (!mpf)
1014                 return 0;
1015
1016         /*
1017          * Now see if we need to go further.
1018          */
1019         if (mpf->feature1 != 0)
1020                 return 0;
1021
1022         if (!mpf->physptr)
1023                 return 0;
1024
1025         mpc = phys_to_virt(mpf->physptr);
1026
1027         if (!smp_check_mpc(mpc, oem, str))
1028                 return 0;
1029
1030         printk(KERN_INFO "mpf: %llx\n", (u64)virt_to_phys(mpf));
1031         printk(KERN_INFO "physptr: %x\n", mpf->physptr);
1032
1033         if (mpc_new_phys && mpc->length > mpc_new_length) {
1034                 mpc_new_phys = 0;
1035                 printk(KERN_INFO "mpc_new_length is %ld, please use alloc_mptable=8k\n",
1036                          mpc_new_length);
1037         }
1038
1039         if (!mpc_new_phys) {
1040                 unsigned char old, new;
1041                 /* check if we can change the postion */
1042                 mpc->checksum = 0;
1043                 old = mpf_checksum((unsigned char *)mpc, mpc->length);
1044                 mpc->checksum = 0xff;
1045                 new = mpf_checksum((unsigned char *)mpc, mpc->length);
1046                 if (old == new) {
1047                         printk(KERN_INFO "mpc is readonly, please try alloc_mptable instead\n");
1048                         return 0;
1049                 }
1050                 printk(KERN_INFO "use in-positon replacing\n");
1051         } else {
1052                 mpf->physptr = mpc_new_phys;
1053                 mpc_new = phys_to_virt(mpc_new_phys);
1054                 memcpy(mpc_new, mpc, mpc->length);
1055                 mpc = mpc_new;
1056                 /* check if we can modify that */
1057                 if (mpc_new_phys - mpf->physptr) {
1058                         struct mpf_intel *mpf_new;
1059                         /* steal 16 bytes from [0, 1k) */
1060                         printk(KERN_INFO "mpf new: %x\n", 0x400 - 16);
1061                         mpf_new = phys_to_virt(0x400 - 16);
1062                         memcpy(mpf_new, mpf, 16);
1063                         mpf = mpf_new;
1064                         mpf->physptr = mpc_new_phys;
1065                 }
1066                 mpf->checksum = 0;
1067                 mpf->checksum -= mpf_checksum((unsigned char *)mpf, 16);
1068                 printk(KERN_INFO "physptr new: %x\n", mpf->physptr);
1069         }
1070
1071         /*
1072          * only replace the one with mp_INT and
1073          *       MP_IRQ_TRIGGER_LEVEL|MP_IRQ_POLARITY_LOW,
1074          * already in mp_irqs , stored by ... and mp_config_acpi_gsi,
1075          * may need pci=routeirq for all coverage
1076          */
1077         replace_intsrc_all(mpc, mpc_new_phys, mpc_new_length);
1078
1079         return 0;
1080 }
1081
1082 late_initcall(update_mp_table);