arch/x86/kernel/mpparse_64.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@redhat.com>
   6  *      (c) 1998, 1999, 2000 Ingo Molnar <mingo@redhat.com>
   7  *
   8  *      Fixes
   9  *              Erich Boleyn    :       MP v1.4 and additional changes.
  10  *              Alan Cox        :       Added EBDA scanning
  11  *              Ingo Molnar     :       various cleanups and rewrites
  12  *              Maciej W. Rozycki:      Bits for default MP configurations
  13  *              Paul Diefenbaugh:       Added full ACPI support
  14  */
  15
  16 #include <linux/mm.h>
  17 #include <linux/init.h>
  18 #include <linux/delay.h>
  19 #include <linux/bootmem.h>
  20 #include <linux/kernel_stat.h>
  21 #include <linux/mc146818rtc.h>
  22 #include <linux/acpi.h>
  23 #include <linux/module.h>
  24
  25 #include <asm/smp.h>
  26 #include <asm/mtrr.h>
  27 #include <asm/mpspec.h>
  28 #include <asm/pgalloc.h>
  29 #include <asm/io_apic.h>
  30 #include <asm/proto.h>
  31 #include <asm/acpi.h>
  32 #include <asm/bios_ebda.h>
  33
  34 #include <mach_apic.h>
  35
  36 /* Have we found an MP table */
  37 int smp_found_config;
  38
  39 /*
  40  * Various Linux-internal data structures created from the
  41  * MP-table.
  42  */
  43 DECLARE_BITMAP(mp_bus_not_pci, MAX_MP_BUSSES);
  44 int mp_bus_id_to_pci_bus[MAX_MP_BUSSES] = {[0 ... MAX_MP_BUSSES - 1] = -1 };
  45
  46 static int mp_current_pci_id = 0;
  47
  48 /* # of MP IRQ source entries */
  49 struct mpc_config_intsrc mp_irqs[MAX_IRQ_SOURCES];
  50
  51 /* MP IRQ source entries */
  52 int mp_irq_entries;
  53
  54 /* Make it easy to share the UP and SMP code: */
  55 #ifndef CONFIG_X86_SMP
  56 unsigned int num_processors;
  57 unsigned disabled_cpus __cpuinitdata;
  58 #ifndef CONFIG_X86_LOCAL_APIC
  59 unsigned int boot_cpu_physical_apicid = -1U;
  60 #endif
  61 #endif
  62
  63 /*
  64  * Intel MP BIOS table parsing routines:
  65  */
  66
  67 /*
  68  * Checksum an MP configuration block.
  69  */
  70
  71 static int __init mpf_checksum(unsigned char *mp, int len)
  72 {
  73         int sum = 0;
  74
  75         while (len--)
  76                 sum += *mp++;
  77
  78         return sum & 0xFF;
  79 }
  80
  81 static void __cpuinit MP_processor_info(struct mpc_config_processor *m)
  82 {
  83         char *bootup_cpu = "";
  84
  85         if (!(m->mpc_cpuflag & CPU_ENABLED)) {
  86                 disabled_cpus++;
  87                 return;
  88         }
  89         if (m->mpc_cpuflag & CPU_BOOTPROCESSOR) {
  90                 bootup_cpu = " (Bootup-CPU)";
  91                 boot_cpu_physical_apicid = m->mpc_apicid;
  92         }
  93
  94         printk(KERN_INFO "Processor #%d%s\n", m->mpc_apicid, bootup_cpu);
  95         generic_processor_info(m->mpc_apicid, 0);
  96 }
  97
  98 static void __init MP_bus_info(struct mpc_config_bus *m)
  99 {
 100         char str[7];
 101
 102         memcpy(str, m->mpc_bustype, 6);
 103         str[6] = 0;
 104         Dprintk("Bus #%d is %s\n", m->mpc_busid, str);
 105
 106         if (strncmp(str, "ISA", 3) == 0) {
 107                 set_bit(m->mpc_busid, mp_bus_not_pci);
 108         } else if (strncmp(str, "PCI", 3) == 0) {
 109                 clear_bit(m->mpc_busid, mp_bus_not_pci);
 110                 mp_bus_id_to_pci_bus[m->mpc_busid] = mp_current_pci_id;
 111                 mp_current_pci_id++;
 112         } else {
 113                 printk(KERN_ERR "Unknown bustype %s\n", str);
 114         }
 115 }
 116
 117 static int bad_ioapic(unsigned long address)
 118 {
 119         if (nr_ioapics >= MAX_IO_APICS) {
 120                 printk(KERN_ERR "ERROR: Max # of I/O APICs (%d) exceeded "
 121                        "(found %d)\n", MAX_IO_APICS, nr_ioapics);
 122                 panic("Recompile kernel with bigger MAX_IO_APICS!\n");
 123         }
 124         if (!address) {
 125                 printk(KERN_ERR "WARNING: Bogus (zero) I/O APIC address"
 126                        " found in table, skipping!\n");
 127                 return 1;
 128         }
 129         return 0;
 130 }
 131
 132 static void __init MP_ioapic_info(struct mpc_config_ioapic *m)
 133 {
 134         if (!(m->mpc_flags & MPC_APIC_USABLE))
 135                 return;
 136
 137         printk(KERN_INFO "I/O APIC #%d at 0x%X.\n", m->mpc_apicid,
 138                m->mpc_apicaddr);
 139
 140         if (bad_ioapic(m->mpc_apicaddr))
 141                 return;
 142
 143         mp_ioapics[nr_ioapics] = *m;
 144         nr_ioapics++;
 145 }
 146
 147 static void __init MP_intsrc_info(struct mpc_config_intsrc *m)
 148 {
 149         mp_irqs[mp_irq_entries] = *m;
 150         Dprintk("Int: type %d, pol %d, trig %d, bus %d,"
 151                 " IRQ %02x, APIC ID %x, APIC INT %02x\n",
 152                 m->mpc_irqtype, m->mpc_irqflag & 3,
 153                 (m->mpc_irqflag >> 2) & 3, m->mpc_srcbus,
 154                 m->mpc_srcbusirq, m->mpc_dstapic, m->mpc_dstirq);
 155         if (++mp_irq_entries >= MAX_IRQ_SOURCES)
 156                 panic("Max # of irq sources exceeded!!\n");
 157 }
 158
 159 static void __init MP_lintsrc_info(struct mpc_config_lintsrc *m)
 160 {
 161         Dprintk("Lint: type %d, pol %d, trig %d, bus %d,"
 162                 " IRQ %02x, APIC ID %x, APIC LINT %02x\n",
 163                 m->mpc_irqtype, m->mpc_irqflag & 3,
 164                 (m->mpc_irqflag >> 2) & 3, m->mpc_srcbusid,
 165                 m->mpc_srcbusirq, m->mpc_destapic, m->mpc_destapiclint);
 166 }
 167
 168 /*
 169  * Read/parse the MPC
 170  */
 171 static int __init smp_read_mpc(struct mp_config_table *mpc, unsigned early)
 172 {
 173         char str[16];
 174         int count = sizeof(*mpc);
 175         unsigned char *mpt = ((unsigned char *)mpc) + count;
 176
 177         if (memcmp(mpc->mpc_signature, MPC_SIGNATURE, 4)) {
 178                 printk(KERN_ERR "MPTABLE: bad signature [%c%c%c%c]!\n",
 179                        mpc->mpc_signature[0],
 180                        mpc->mpc_signature[1],
 181                        mpc->mpc_signature[2], mpc->mpc_signature[3]);
 182                 return 0;
 183         }
 184         if (mpf_checksum((unsigned char *)mpc, mpc->mpc_length)) {
 185                 printk(KERN_ERR "MPTABLE: checksum error!\n");
 186                 return 0;
 187         }
 188         if (mpc->mpc_spec != 0x01 && mpc->mpc_spec != 0x04) {
 189                 printk(KERN_ERR "MPTABLE: bad table version (%d)!!\n",
 190                        mpc->mpc_spec);
 191                 return 0;
 192         }
 193         if (!mpc->mpc_lapic) {
 194                 printk(KERN_ERR "MPTABLE: null local APIC address!\n");
 195                 return 0;
 196         }
 197         memcpy(str, mpc->mpc_oem, 8);
 198         str[8] = 0;
 199         printk(KERN_INFO "MPTABLE: OEM ID: %s ", str);
 200
 201         memcpy(str, mpc->mpc_productid, 12);
 202         str[12] = 0;
 203         printk(KERN_INFO "MPTABLE: Product ID: %s ", str);
 204
 205         printk(KERN_INFO "MPTABLE: APIC at: 0x%X\n", mpc->mpc_lapic);
 206
 207         /* save the local APIC address, it might be non-default */
 208         if (!acpi_lapic)
 209                 mp_lapic_addr = mpc->mpc_lapic;
 210
 211         if (early)
 212                 return 1;
 213
 214         /*
 215          *      Now process the configuration blocks.
 216          */
 217         while (count < mpc->mpc_length) {
 218                 switch (*mpt) {
 219                 case MP_PROCESSOR:
 220                         {
 221                                 struct mpc_config_processor *m =
 222                                     (struct mpc_config_processor *)mpt;
 223                                 if (!acpi_lapic)
 224                                         MP_processor_info(m);
 225                                 mpt += sizeof(*m);
 226                                 count += sizeof(*m);
 227                                 break;
 228                         }
 229                 case MP_BUS:
 230                         {
 231                                 struct mpc_config_bus *m =
 232                                     (struct mpc_config_bus *)mpt;
 233                                 MP_bus_info(m);
 234                                 mpt += sizeof(*m);
 235                                 count += sizeof(*m);
 236                                 break;
 237                         }
 238                 case MP_IOAPIC:
 239                         {
 240                                 struct mpc_config_ioapic *m =
 241                                     (struct mpc_config_ioapic *)mpt;
 242                                 MP_ioapic_info(m);
 243                                 mpt += sizeof(*m);
 244                                 count += sizeof(*m);
 245                                 break;
 246                         }
 247                 case MP_INTSRC:
 248                         {
 249                                 struct mpc_config_intsrc *m =
 250                                     (struct mpc_config_intsrc *)mpt;
 251
 252                                 MP_intsrc_info(m);
 253                                 mpt += sizeof(*m);
 254                                 count += sizeof(*m);
 255                                 break;
 256                         }
 257                 case MP_LINTSRC:
 258                         {
 259                                 struct mpc_config_lintsrc *m =
 260                                     (struct mpc_config_lintsrc *)mpt;
 261                                 MP_lintsrc_info(m);
 262                                 mpt += sizeof(*m);
 263                                 count += sizeof(*m);
 264                                 break;
 265                         }
 266                 }
 267         }
 268         setup_apic_routing();
 269         if (!num_processors)
 270                 printk(KERN_ERR "MPTABLE: no processors registered!\n");
 271         return num_processors;
 272 }
 273
 274 static int __init ELCR_trigger(unsigned int irq)
 275 {
 276         unsigned int port;
 277
 278         port = 0x4d0 + (irq >> 3);
 279         return (inb(port) >> (irq & 7)) & 1;
 280 }
 281
 282 static void __init construct_default_ioirq_mptable(int mpc_default_type)
 283 {
 284         struct mpc_config_intsrc intsrc;
 285         int i;
 286         int ELCR_fallback = 0;
 287
 288         intsrc.mpc_type = MP_INTSRC;
 289         intsrc.mpc_irqflag = 0; /* conforming */
 290         intsrc.mpc_srcbus = 0;
 291         intsrc.mpc_dstapic = mp_ioapics[0].mpc_apicid;
 292
 293         intsrc.mpc_irqtype = mp_INT;
 294
 295         /*
 296          *  If true, we have an ISA/PCI system with no IRQ entries
 297          *  in the MP table. To prevent the PCI interrupts from being set up
 298          *  incorrectly, we try to use the ELCR. The sanity check to see if
 299          *  there is good ELCR data is very simple - IRQ0, 1, 2 and 13 can
 300          *  never be level sensitive, so we simply see if the ELCR agrees.
 301          *  If it does, we assume it's valid.
 302          */
 303         if (mpc_default_type == 5) {
 304                 printk(KERN_INFO "ISA/PCI bus type with no IRQ information... "
 305                        "falling back to ELCR\n");
 306
 307                 if (ELCR_trigger(0) || ELCR_trigger(1) || ELCR_trigger(2) ||
 308                     ELCR_trigger(13))
 309                         printk(KERN_ERR "ELCR contains invalid data... "
 310                                "not using ELCR\n");
 311                 else {
 312                         printk(KERN_INFO
 313                                "Using ELCR to identify PCI interrupts\n");
 314                         ELCR_fallback = 1;
 315                 }
 316         }
 317
 318         for (i = 0; i < 16; i++) {
 319                 switch (mpc_default_type) {
 320                 case 2:
 321                         if (i == 0 || i == 13)
 322                                 continue;       /* IRQ0 & IRQ13 not connected */
 323                         /* fall through */
 324                 default:
 325                         if (i == 2)
 326                                 continue;       /* IRQ2 is never connected */
 327                 }
 328
 329                 if (ELCR_fallback) {
 330                         /*
 331                          *  If the ELCR indicates a level-sensitive interrupt, we
 332                          *  copy that information over to the MP table in the
 333                          *  irqflag field (level sensitive, active high polarity).
 334                          */
 335                         if (ELCR_trigger(i))
 336                                 intsrc.mpc_irqflag = 13;
 337                         else
 338                                 intsrc.mpc_irqflag = 0;
 339                 }
 340
 341                 intsrc.mpc_srcbusirq = i;
 342                 intsrc.mpc_dstirq = i ? i : 2;  /* IRQ0 to INTIN2 */
 343                 MP_intsrc_info(&intsrc);
 344         }
 345
 346         intsrc.mpc_irqtype = mp_ExtINT;
 347         intsrc.mpc_srcbusirq = 0;
 348         intsrc.mpc_dstirq = 0;  /* 8259A to INTIN0 */
 349         MP_intsrc_info(&intsrc);
 350 }
 351
 352 static inline void __init construct_default_ISA_mptable(int mpc_default_type)
 353 {
 354         struct mpc_config_processor processor;
 355         struct mpc_config_bus bus;
 356         struct mpc_config_ioapic ioapic;
 357         struct mpc_config_lintsrc lintsrc;
 358         int linttypes[2] = { mp_ExtINT, mp_NMI };
 359         int i;
 360
 361         /*
 362          * local APIC has default address
 363          */
 364         mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
 365
 366         /*
 367          * 2 CPUs, numbered 0 & 1.
 368          */
 369         processor.mpc_type = MP_PROCESSOR;
 370         processor.mpc_apicver = 0;
 371         processor.mpc_cpuflag = CPU_ENABLED;
 372         processor.mpc_cpufeature = 0;
 373         processor.mpc_featureflag = 0;
 374         processor.mpc_reserved[0] = 0;
 375         processor.mpc_reserved[1] = 0;
 376         for (i = 0; i < 2; i++) {
 377                 processor.mpc_apicid = i;
 378                 MP_processor_info(&processor);
 379         }
 380
 381         bus.mpc_type = MP_BUS;
 382         bus.mpc_busid = 0;
 383         switch (mpc_default_type) {
 384         default:
 385                 printk(KERN_ERR "???\nUnknown standard configuration %d\n",
 386                        mpc_default_type);
 387                 /* fall through */
 388         case 1:
 389         case 5:
 390                 memcpy(bus.mpc_bustype, "ISA   ", 6);
 391                 break;
 392         }
 393         MP_bus_info(&bus);
 394         if (mpc_default_type > 4) {
 395                 bus.mpc_busid = 1;
 396                 memcpy(bus.mpc_bustype, "PCI   ", 6);
 397                 MP_bus_info(&bus);
 398         }
 399
 400         ioapic.mpc_type = MP_IOAPIC;
 401         ioapic.mpc_apicid = 2;
 402         ioapic.mpc_apicver = 0;
 403         ioapic.mpc_flags = MPC_APIC_USABLE;
 404         ioapic.mpc_apicaddr = 0xFEC00000;
 405         MP_ioapic_info(&ioapic);
 406
 407         /*
 408          * We set up most of the low 16 IO-APIC pins according to MPS rules.
 409          */
 410         construct_default_ioirq_mptable(mpc_default_type);
 411
 412         lintsrc.mpc_type = MP_LINTSRC;
 413         lintsrc.mpc_irqflag = 0;        /* conforming */
 414         lintsrc.mpc_srcbusid = 0;
 415         lintsrc.mpc_srcbusirq = 0;
 416         lintsrc.mpc_destapic = MP_APIC_ALL;
 417         for (i = 0; i < 2; i++) {
 418                 lintsrc.mpc_irqtype = linttypes[i];
 419                 lintsrc.mpc_destapiclint = i;
 420                 MP_lintsrc_info(&lintsrc);
 421         }
 422 }
 423
 424 static struct intel_mp_floating *mpf_found;
 425
 426 /*
 427  * Scan the memory blocks for an SMP configuration block.
 428  */
 429 static void __init __get_smp_config(unsigned early)
 430 {
 431         struct intel_mp_floating *mpf = mpf_found;
 432
 433         if (acpi_lapic && early)
 434                 return;
 435         /*
 436          * ACPI supports both logical (e.g. Hyper-Threading) and physical
 437          * processors, where MPS only supports physical.
 438          */
 439         if (acpi_lapic && acpi_ioapic) {
 440                 printk(KERN_INFO "Using ACPI (MADT) for SMP configuration "
 441                        "information\n");
 442                 return;
 443         } else if (acpi_lapic)
 444                 printk(KERN_INFO "Using ACPI for processor (LAPIC) "
 445                        "configuration information\n");
 446
 447         printk(KERN_INFO "Intel MultiProcessor Specification v1.%d\n",
 448                mpf->mpf_specification);
 449
 450         /*
 451          * Now see if we need to read further.
 452          */
 453         if (mpf->mpf_feature1 != 0) {
 454                 if (early) {
 455                         /*
 456                          * local APIC has default address
 457                          */
 458                         mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
 459                         return;
 460                 }
 461
 462                 printk(KERN_INFO "Default MP configuration #%d\n",
 463                        mpf->mpf_feature1);
 464                 construct_default_ISA_mptable(mpf->mpf_feature1);
 465
 466         } else if (mpf->mpf_physptr) {
 467
 468                 /*
 469                  * Read the physical hardware table.  Anything here will
 470                  * override the defaults.
 471                  */
 472                 if (!smp_read_mpc(phys_to_virt(mpf->mpf_physptr), early)) {
 473                         smp_found_config = 0;
 474                         printk(KERN_ERR
 475                                "BIOS bug, MP table errors detected!...\n");
 476                         printk(KERN_ERR "... disabling SMP support. "
 477                                "(tell your hw vendor)\n");
 478                         return;
 479                 }
 480
 481                 if (early)
 482                         return;
 483                 /*
 484                  * If there are no explicit MP IRQ entries, then we are
 485                  * broken.  We set up most of the low 16 IO-APIC pins to
 486                  * ISA defaults and hope it will work.
 487                  */
 488                 if (!mp_irq_entries) {
 489                         struct mpc_config_bus bus;
 490
 491                         printk(KERN_ERR "BIOS bug, no explicit IRQ entries, "
 492                                "using default mptable. "
 493                                "(tell your hw vendor)\n");
 494
 495                         bus.mpc_type = MP_BUS;
 496                         bus.mpc_busid = 0;
 497                         memcpy(bus.mpc_bustype, "ISA   ", 6);
 498                         MP_bus_info(&bus);
 499
 500                         construct_default_ioirq_mptable(0);
 501                 }
 502
 503         } else
 504                 BUG();
 505
 506         if (!early)
 507                 printk(KERN_INFO "Processors: %d\n", num_processors);
 508         /*
 509          * Only use the first configuration found.
 510          */
 511 }
 512
 513 void __init early_get_smp_config(void)
 514 {
 515         __get_smp_config(1);
 516 }
 517
 518 void __init get_smp_config(void)
 519 {
 520         __get_smp_config(0);
 521 }
 522
 523 static int __init smp_scan_config(unsigned long base, unsigned long length,
 524                                   unsigned reserve)
 525 {
 526         extern void __bad_mpf_size(void);
 527         unsigned int *bp = phys_to_virt(base);
 528         struct intel_mp_floating *mpf;
 529
 530         Dprintk("Scan SMP from %p for %ld bytes.\n", bp, length);
 531         if (sizeof(*mpf) != 16)
 532                 __bad_mpf_size();
 533
 534         while (length > 0) {
 535                 mpf = (struct intel_mp_floating *)bp;
 536                 if ((*bp == SMP_MAGIC_IDENT) &&
 537                     (mpf->mpf_length == 1) &&
 538                     !mpf_checksum((unsigned char *)bp, 16) &&
 539                     ((mpf->mpf_specification == 1)
 540                      || (mpf->mpf_specification == 4))) {
 541
 542                         smp_found_config = 1;
 543                         mpf_found = mpf;
 544
 545                         if (!reserve)
 546                                 return 1;
 547
 548                         reserve_bootmem_generic(virt_to_phys(mpf), PAGE_SIZE);
 549                         if (mpf->mpf_physptr)
 550                                 reserve_bootmem_generic(mpf->mpf_physptr,
 551                                                         PAGE_SIZE);
 552                         return 1;
 553                 }
 554                 bp += 4;
 555                 length -= 16;
 556         }
 557         return 0;
 558 }
 559
 560 static void __init __find_smp_config(unsigned reserve)
 561 {
 562         unsigned int address;
 563
 564         /*
 565          * FIXME: Linux assumes you have 640K of base ram..
 566          * this continues the error...
 567          *
 568          * 1) Scan the bottom 1K for a signature
 569          * 2) Scan the top 1K of base RAM
 570          * 3) Scan the 64K of bios
 571          */
 572         if (smp_scan_config(0x0, 0x400, reserve) ||
 573             smp_scan_config(639 * 0x400, 0x400, reserve) ||
 574             smp_scan_config(0xF0000, 0x10000, reserve))
 575                 return;
 576         /*
 577          * If it is an SMP machine we should know now.
 578          *
 579          * there is a real-mode segmented pointer pointing to the
 580          * 4K EBDA area at 0x40E, calculate and scan it here.
 581          *
 582          * NOTE! There are Linux loaders that will corrupt the EBDA
 583          * area, and as such this kind of SMP config may be less
 584          * trustworthy, simply because the SMP table may have been
 585          * stomped on during early boot. These loaders are buggy and
 586          * should be fixed.
 587          *
 588          * MP1.4 SPEC states to only scan first 1K of 4K EBDA.
 589          */
 590
 591         address = get_bios_ebda();
 592         if (address)
 593                 smp_scan_config(address, 0x400, reserve);
 594 }
 595
 596 void __init early_find_smp_config(void)
 597 {
 598         __find_smp_config(0);
 599 }
 600
 601 void __init find_smp_config(void)
 602 {
 603         __find_smp_config(1);
 604 }
 605
 606 /* --------------------------------------------------------------------------
 607                             ACPI-based MP Configuration
 608    -------------------------------------------------------------------------- */
 609
 610 #ifdef CONFIG_ACPI
 611
 612 void __init mp_register_lapic_address(u64 address)
 613 {
 614         mp_lapic_addr = (unsigned long)address;
 615         set_fixmap_nocache(FIX_APIC_BASE, mp_lapic_addr);
 616         if (boot_cpu_physical_apicid == -1U)
 617                 boot_cpu_physical_apicid  = GET_APIC_ID(read_apic_id());
 618 }
 619 void __cpuinit mp_register_lapic(int id, u8 enabled)
 620 {
 621         if (!enabled) {
 622                 ++disabled_cpus;
 623                 return;
 624         }
 625
 626         generic_processor_info(id, 0);
 627 }
 628
 629
 630 #define MP_ISA_BUS              0
 631 #define MP_MAX_IOAPIC_PIN       127
 632
 633 extern struct mp_ioapic_routing mp_ioapic_routing[MAX_IO_APICS];
 634
 635 static int mp_find_ioapic(int gsi)
 636 {
 637         int i = 0;
 638
 639         /* Find the IOAPIC that manages this GSI. */
 640         for (i = 0; i < nr_ioapics; i++) {
 641                 if ((gsi >= mp_ioapic_routing[i].gsi_base)
 642                     && (gsi <= mp_ioapic_routing[i].gsi_end))
 643                         return i;
 644         }
 645
 646         printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
 647         return -1;
 648 }
 649
 650 static u8 uniq_ioapic_id(u8 id)
 651 {
 652         int i;
 653         DECLARE_BITMAP(used, 256);
 654         bitmap_zero(used, 256);
 655         for (i = 0; i < nr_ioapics; i++) {
 656                 struct mpc_config_ioapic *ia = &mp_ioapics[i];
 657                 __set_bit(ia->mpc_apicid, used);
 658         }
 659         if (!test_bit(id, used))
 660                 return id;
 661         return find_first_zero_bit(used, 256);
 662 }
 663
 664 void __init mp_register_ioapic(int id, u32 address, u32 gsi_base)
 665 {
 666         int idx = 0;
 667
 668         if (bad_ioapic(address))
 669                 return;
 670
 671         idx = nr_ioapics;
 672
 673         mp_ioapics[idx].mpc_type = MP_IOAPIC;
 674         mp_ioapics[idx].mpc_flags = MPC_APIC_USABLE;
 675         mp_ioapics[idx].mpc_apicaddr = address;
 676
 677         set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address);
 678         mp_ioapics[idx].mpc_apicid = uniq_ioapic_id(id);
 679         mp_ioapics[idx].mpc_apicver = 0;
 680
 681         /*
 682          * Build basic IRQ lookup table to facilitate gsi->io_apic lookups
 683          * and to prevent reprogramming of IOAPIC pins (PCI IRQs).
 684          */
 685         mp_ioapic_routing[idx].apic_id = mp_ioapics[idx].mpc_apicid;
 686         mp_ioapic_routing[idx].gsi_base = gsi_base;
 687         mp_ioapic_routing[idx].gsi_end = gsi_base +
 688             io_apic_get_redir_entries(idx);
 689
 690         printk(KERN_INFO "IOAPIC[%d]: apic_id %d, address 0x%x, "
 691                "GSI %d-%d\n", idx, mp_ioapics[idx].mpc_apicid,
 692                mp_ioapics[idx].mpc_apicaddr,
 693                mp_ioapic_routing[idx].gsi_base,
 694                mp_ioapic_routing[idx].gsi_end);
 695
 696         nr_ioapics++;
 697 }
 698
 699 void __init mp_override_legacy_irq(u8 bus_irq, u8 polarity, u8 trigger, u32 gsi)
 700 {
 701         struct mpc_config_intsrc intsrc;
 702         int ioapic = -1;
 703         int pin = -1;
 704
 705         /*
 706          * Convert 'gsi' to 'ioapic.pin'.
 707          */
 708         ioapic = mp_find_ioapic(gsi);
 709         if (ioapic < 0)
 710                 return;
 711         pin = gsi - mp_ioapic_routing[ioapic].gsi_base;
 712
 713         /*
 714          * TBD: This check is for faulty timer entries, where the override
 715          *      erroneously sets the trigger to level, resulting in a HUGE
 716          *      increase of timer interrupts!
 717          */
 718         if ((bus_irq == 0) && (trigger == 3))
 719                 trigger = 1;
 720
 721         intsrc.mpc_type = MP_INTSRC;
 722         intsrc.mpc_irqtype = mp_INT;
 723         intsrc.mpc_irqflag = (trigger << 2) | polarity;
 724         intsrc.mpc_srcbus = MP_ISA_BUS;
 725         intsrc.mpc_srcbusirq = bus_irq; /* IRQ */
 726         intsrc.mpc_dstapic = mp_ioapics[ioapic].mpc_apicid;     /* APIC ID */
 727         intsrc.mpc_dstirq = pin;        /* INTIN# */
 728
 729         Dprintk("Int: type %d, pol %d, trig %d, bus %d, irq %d, %d-%d\n",
 730                 intsrc.mpc_irqtype, intsrc.mpc_irqflag & 3,
 731                 (intsrc.mpc_irqflag >> 2) & 3, intsrc.mpc_srcbus,
 732                 intsrc.mpc_srcbusirq, intsrc.mpc_dstapic, intsrc.mpc_dstirq);
 733
 734         mp_irqs[mp_irq_entries] = intsrc;
 735         if (++mp_irq_entries == MAX_IRQ_SOURCES)
 736                 panic("Max # of irq sources exceeded!\n");
 737 }
 738
 739 void __init mp_config_acpi_legacy_irqs(void)
 740 {
 741         struct mpc_config_intsrc intsrc;
 742         int i = 0;
 743         int ioapic = -1;
 744
 745         /*
 746          * Fabricate the legacy ISA bus (bus #31).
 747          */
 748         set_bit(MP_ISA_BUS, mp_bus_not_pci);
 749
 750         /*
 751          * Locate the IOAPIC that manages the ISA IRQs (0-15).
 752          */
 753         ioapic = mp_find_ioapic(0);
 754         if (ioapic < 0)
 755                 return;
 756
 757         intsrc.mpc_type = MP_INTSRC;
 758         intsrc.mpc_irqflag = 0; /* Conforming */
 759         intsrc.mpc_srcbus = MP_ISA_BUS;
 760         intsrc.mpc_dstapic = mp_ioapics[ioapic].mpc_apicid;
 761
 762         /*
 763          * Use the default configuration for the IRQs 0-15.  Unless
 764          * overridden by (MADT) interrupt source override entries.
 765          */
 766         for (i = 0; i < 16; i++) {
 767                 int idx;
 768
 769                 for (idx = 0; idx < mp_irq_entries; idx++) {
 770                         struct mpc_config_intsrc *irq = mp_irqs + idx;
 771
 772                         /* Do we already have a mapping for this ISA IRQ? */
 773                         if (irq->mpc_srcbus == MP_ISA_BUS
 774                             && irq->mpc_srcbusirq == i)
 775                                 break;
 776
 777                         /* Do we already have a mapping for this IOAPIC pin */
 778                         if ((irq->mpc_dstapic == intsrc.mpc_dstapic) &&
 779                             (irq->mpc_dstirq == i))
 780                                 break;
 781                 }
 782
 783                 if (idx != mp_irq_entries) {
 784                         printk(KERN_DEBUG "ACPI: IRQ%d used by override.\n", i);
 785                         continue;       /* IRQ already used */
 786                 }
 787
 788                 intsrc.mpc_irqtype = mp_INT;
 789                 intsrc.mpc_srcbusirq = i;       /* Identity mapped */
 790                 intsrc.mpc_dstirq = i;
 791
 792                 Dprintk("Int: type %d, pol %d, trig %d, bus %d, irq %d, "
 793                         "%d-%d\n", intsrc.mpc_irqtype, intsrc.mpc_irqflag & 3,
 794                         (intsrc.mpc_irqflag >> 2) & 3, intsrc.mpc_srcbus,
 795                         intsrc.mpc_srcbusirq, intsrc.mpc_dstapic,
 796                         intsrc.mpc_dstirq);
 797
 798                 mp_irqs[mp_irq_entries] = intsrc;
 799                 if (++mp_irq_entries == MAX_IRQ_SOURCES)
 800                         panic("Max # of irq sources exceeded!\n");
 801         }
 802 }
 803
 804 int mp_register_gsi(u32 gsi, int triggering, int polarity)
 805 {
 806         int ioapic = -1;
 807         int ioapic_pin = 0;
 808         int idx, bit = 0;
 809
 810         if (acpi_irq_model != ACPI_IRQ_MODEL_IOAPIC)
 811                 return gsi;
 812
 813         /* Don't set up the ACPI SCI because it's already set up */
 814         if (acpi_gbl_FADT.sci_interrupt == gsi)
 815                 return gsi;
 816
 817         ioapic = mp_find_ioapic(gsi);
 818         if (ioapic < 0) {
 819                 printk(KERN_WARNING "No IOAPIC for GSI %u\n", gsi);
 820                 return gsi;
 821         }
 822
 823         ioapic_pin = gsi - mp_ioapic_routing[ioapic].gsi_base;
 824
 825         /*
 826          * Avoid pin reprogramming.  PRTs typically include entries
 827          * with redundant pin->gsi mappings (but unique PCI devices);
 828          * we only program the IOAPIC on the first.
 829          */
 830         bit = ioapic_pin % 32;
 831         idx = (ioapic_pin < 32) ? 0 : (ioapic_pin / 32);
 832         if (idx > 3) {
 833                 printk(KERN_ERR "Invalid reference to IOAPIC pin "
 834                        "%d-%d\n", mp_ioapic_routing[ioapic].apic_id,
 835                        ioapic_pin);
 836                 return gsi;
 837         }
 838         if ((1 << bit) & mp_ioapic_routing[ioapic].pin_programmed[idx]) {
 839                 Dprintk(KERN_DEBUG "Pin %d-%d already programmed\n",
 840                         mp_ioapic_routing[ioapic].apic_id, ioapic_pin);
 841                 return gsi;
 842         }
 843
 844         mp_ioapic_routing[ioapic].pin_programmed[idx] |= (1 << bit);
 845
 846         io_apic_set_pci_routing(ioapic, ioapic_pin, gsi,
 847                                 triggering == ACPI_EDGE_SENSITIVE ? 0 : 1,
 848                                 polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
 849         return gsi;
 850 }
 851 #endif /* CONFIG_ACPI */