arch/i386/kernel/acpi/boot.c

   1 /*
   2  *  boot.c - Architecture-Specific Low-Level ACPI Boot Support
   3  *
   4  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   5  *  Copyright (C) 2001 Jun Nakajima <jun.nakajima@intel.com>
   6  *
   7  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   8  *
   9  *  This program is free software; you can redistribute it and/or modify
  10  *  it under the terms of the GNU General Public License as published by
  11  *  the Free Software Foundation; either version 2 of the License, or
  12  *  (at your option) any later version.
  13  *
  14  *  This program is distributed in the hope that it will be useful,
  15  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *  GNU General Public License for more details.
  18  *
  19  *  You should have received a copy of the GNU General Public License
  20  *  along with this program; if not, write to the Free Software
  21  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  22  *
  23  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  24  */
  25
  26 #include <linux/init.h>
  27 #include <linux/acpi.h>
  28 #include <linux/efi.h>
  29 #include <linux/cpumask.h>
  30 #include <linux/module.h>
  31 #include <linux/dmi.h>
  32 #include <linux/irq.h>
  33 #include <linux/bootmem.h>
  34 #include <linux/ioport.h>
  35
  36 #include <asm/pgtable.h>
  37 #include <asm/io_apic.h>
  38 #include <asm/apic.h>
  39 #include <asm/io.h>
  40 #include <asm/mpspec.h>
  41
  42 static int __initdata acpi_force = 0;
  43
  44 #ifdef  CONFIG_ACPI
  45 int acpi_disabled = 0;
  46 #else
  47 int acpi_disabled = 1;
  48 #endif
  49 EXPORT_SYMBOL(acpi_disabled);
  50
  51 #ifdef  CONFIG_X86_64
  52
  53 #include <asm/proto.h>
  54
  55 static inline int acpi_madt_oem_check(char *oem_id, char *oem_table_id) { return 0; }
  56
  57
  58 #else                           /* X86 */
  59
  60 #ifdef  CONFIG_X86_LOCAL_APIC
  61 #include <mach_apic.h>
  62 #include <mach_mpparse.h>
  63 #endif                          /* CONFIG_X86_LOCAL_APIC */
  64
  65 #endif                          /* X86 */
  66
  67 #define BAD_MADT_ENTRY(entry, end) (                                        \
  68                 (!entry) || (unsigned long)entry + sizeof(*entry) > end ||  \
  69                 ((struct acpi_subtable_header *)entry)->length < sizeof(*entry))
  70
  71 #define PREFIX                  "ACPI: "
  72
  73 int acpi_noirq;                         /* skip ACPI IRQ initialization */
  74 int acpi_pci_disabled __initdata;       /* skip ACPI PCI scan and IRQ initialization */
  75 int acpi_ht __initdata = 1;     /* enable HT */
  76
  77 int acpi_lapic;
  78 int acpi_ioapic;
  79 int acpi_strict;
  80 EXPORT_SYMBOL(acpi_strict);
  81
  82 u8 acpi_sci_flags __initdata;
  83 int acpi_sci_override_gsi __initdata;
  84 int acpi_skip_timer_override __initdata;
  85 int acpi_use_timer_override __initdata;
  86
  87 #ifdef CONFIG_X86_LOCAL_APIC
  88 static u64 acpi_lapic_addr __initdata = APIC_DEFAULT_PHYS_BASE;
  89 #endif
  90
  91 #ifndef __HAVE_ARCH_CMPXCHG
  92 #warning ACPI uses CMPXCHG, i486 and later hardware
  93 #endif
  94
  95 /* --------------------------------------------------------------------------
  96                               Boot-time Configuration
  97    -------------------------------------------------------------------------- */
  98
  99 /*
 100  * The default interrupt routing model is PIC (8259).  This gets
 101  * overriden if IOAPICs are enumerated (below).
 102  */
 103 enum acpi_irq_model_id acpi_irq_model = ACPI_IRQ_MODEL_PIC;
 104
 105 #ifdef  CONFIG_X86_64
 106
 107 /* rely on all ACPI tables being in the direct mapping */
 108 char *__acpi_map_table(unsigned long phys_addr, unsigned long size)
 109 {
 110         if (!phys_addr || !size)
 111                 return NULL;
 112
 113         if (phys_addr+size <= (end_pfn_map << PAGE_SHIFT) + PAGE_SIZE)
 114                 return __va(phys_addr);
 115
 116         return NULL;
 117 }
 118
 119 #else
 120
 121 /*
 122  * Temporarily use the virtual area starting from FIX_IO_APIC_BASE_END,
 123  * to map the target physical address. The problem is that set_fixmap()
 124  * provides a single page, and it is possible that the page is not
 125  * sufficient.
 126  * By using this area, we can map up to MAX_IO_APICS pages temporarily,
 127  * i.e. until the next __va_range() call.
 128  *
 129  * Important Safety Note:  The fixed I/O APIC page numbers are *subtracted*
 130  * from the fixed base.  That's why we start at FIX_IO_APIC_BASE_END and
 131  * count idx down while incrementing the phys address.
 132  */
 133 char *__acpi_map_table(unsigned long phys, unsigned long size)
 134 {
 135         unsigned long base, offset, mapped_size;
 136         int idx;
 137
 138         if (phys + size < 8 * 1024 * 1024)
 139                 return __va(phys);
 140
 141         offset = phys & (PAGE_SIZE - 1);
 142         mapped_size = PAGE_SIZE - offset;
 143         set_fixmap(FIX_ACPI_END, phys);
 144         base = fix_to_virt(FIX_ACPI_END);
 145
 146         /*
 147          * Most cases can be covered by the below.
 148          */
 149         idx = FIX_ACPI_END;
 150         while (mapped_size < size) {
 151                 if (--idx < FIX_ACPI_BEGIN)
 152                         return NULL;    /* cannot handle this */
 153                 phys += PAGE_SIZE;
 154                 set_fixmap(idx, phys);
 155                 mapped_size += PAGE_SIZE;
 156         }
 157
 158         return ((unsigned char *)base + offset);
 159 }
 160 #endif
 161
 162 #ifdef CONFIG_PCI_MMCONFIG
 163 /* The physical address of the MMCONFIG aperture.  Set from ACPI tables. */
 164 struct acpi_mcfg_allocation *pci_mmcfg_config;
 165 int pci_mmcfg_config_num;
 166
 167 int __init acpi_parse_mcfg(struct acpi_table_header *header)
 168 {
 169         struct acpi_table_mcfg *mcfg;
 170         unsigned long i;
 171         int config_size;
 172
 173         if (!header)
 174                 return -EINVAL;
 175
 176         mcfg = (struct acpi_table_mcfg *)header;
 177
 178         /* how many config structures do we have */
 179         pci_mmcfg_config_num = 0;
 180         i = header->length - sizeof(struct acpi_table_mcfg);
 181         while (i >= sizeof(struct acpi_mcfg_allocation)) {
 182                 ++pci_mmcfg_config_num;
 183                 i -= sizeof(struct acpi_mcfg_allocation);
 184         };
 185         if (pci_mmcfg_config_num == 0) {
 186                 printk(KERN_ERR PREFIX "MMCONFIG has no entries\n");
 187                 return -ENODEV;
 188         }
 189
 190         config_size = pci_mmcfg_config_num * sizeof(*pci_mmcfg_config);
 191         pci_mmcfg_config = kmalloc(config_size, GFP_KERNEL);
 192         if (!pci_mmcfg_config) {
 193                 printk(KERN_WARNING PREFIX
 194                        "No memory for MCFG config tables\n");
 195                 return -ENOMEM;
 196         }
 197
 198         memcpy(pci_mmcfg_config, &mcfg[1], config_size);
 199         for (i = 0; i < pci_mmcfg_config_num; ++i) {
 200                 if (pci_mmcfg_config[i].address > 0xFFFFFFFF) {
 201                         printk(KERN_ERR PREFIX
 202                                "MMCONFIG not in low 4GB of memory\n");
 203                         kfree(pci_mmcfg_config);
 204                         pci_mmcfg_config_num = 0;
 205                         return -ENODEV;
 206                 }
 207         }
 208
 209         return 0;
 210 }
 211 #endif                          /* CONFIG_PCI_MMCONFIG */
 212
 213 #ifdef CONFIG_X86_LOCAL_APIC
 214 static int __init acpi_parse_madt(struct acpi_table_header *table)
 215 {
 216         struct acpi_table_madt *madt = NULL;
 217
 218         if (!cpu_has_apic)
 219                 return -EINVAL;
 220
 221         madt = (struct acpi_table_madt *)table;
 222         if (!madt) {
 223                 printk(KERN_WARNING PREFIX "Unable to map MADT\n");
 224                 return -ENODEV;
 225         }
 226
 227         if (madt->address) {
 228                 acpi_lapic_addr = (u64) madt->address;
 229
 230                 printk(KERN_DEBUG PREFIX "Local APIC address 0x%08x\n",
 231                        madt->address);
 232         }
 233
 234         acpi_madt_oem_check(madt->header.oem_id, madt->header.oem_table_id);
 235
 236         return 0;
 237 }
 238
 239 static int __init
 240 acpi_parse_lapic(struct acpi_subtable_header * header, const unsigned long end)
 241 {
 242         struct acpi_madt_local_apic *processor = NULL;
 243
 244         processor = (struct acpi_madt_local_apic *)header;
 245
 246         if (BAD_MADT_ENTRY(processor, end))
 247                 return -EINVAL;
 248
 249         acpi_table_print_madt_entry(header);
 250
 251         /*
 252          * We need to register disabled CPU as well to permit
 253          * counting disabled CPUs. This allows us to size
 254          * cpus_possible_map more accurately, to permit
 255          * to not preallocating memory for all NR_CPUS
 256          * when we use CPU hotplug.
 257          */
 258         mp_register_lapic(processor->id,        /* APIC ID */
 259                           processor->lapic_flags & ACPI_MADT_ENABLED);  /* Enabled? */
 260
 261         return 0;
 262 }
 263
 264 static int __init
 265 acpi_parse_lapic_addr_ovr(struct acpi_subtable_header * header,
 266                           const unsigned long end)
 267 {
 268         struct acpi_madt_local_apic_override *lapic_addr_ovr = NULL;
 269
 270         lapic_addr_ovr = (struct acpi_madt_local_apic_override *)header;
 271
 272         if (BAD_MADT_ENTRY(lapic_addr_ovr, end))
 273                 return -EINVAL;
 274
 275         acpi_lapic_addr = lapic_addr_ovr->address;
 276
 277         return 0;
 278 }
 279
 280 static int __init
 281 acpi_parse_lapic_nmi(struct acpi_subtable_header * header, const unsigned long end)
 282 {
 283         struct acpi_madt_local_apic_nmi *lapic_nmi = NULL;
 284
 285         lapic_nmi = (struct acpi_madt_local_apic_nmi *)header;
 286
 287         if (BAD_MADT_ENTRY(lapic_nmi, end))
 288                 return -EINVAL;
 289
 290         acpi_table_print_madt_entry(header);
 291
 292         if (lapic_nmi->lint != 1)
 293                 printk(KERN_WARNING PREFIX "NMI not connected to LINT 1!\n");
 294
 295         return 0;
 296 }
 297
 298 #endif                          /*CONFIG_X86_LOCAL_APIC */
 299
 300 #ifdef CONFIG_X86_IO_APIC
 301
 302 static int __init
 303 acpi_parse_ioapic(struct acpi_subtable_header * header, const unsigned long end)
 304 {
 305         struct acpi_madt_io_apic *ioapic = NULL;
 306
 307         ioapic = (struct acpi_madt_io_apic *)header;
 308
 309         if (BAD_MADT_ENTRY(ioapic, end))
 310                 return -EINVAL;
 311
 312         acpi_table_print_madt_entry(header);
 313
 314         mp_register_ioapic(ioapic->id,
 315                            ioapic->address, ioapic->global_irq_base);
 316
 317         return 0;
 318 }
 319
 320 /*
 321  * Parse Interrupt Source Override for the ACPI SCI
 322  */
 323 static void __init acpi_sci_ioapic_setup(u32 gsi, u16 polarity, u16 trigger)
 324 {
 325         if (trigger == 0)       /* compatible SCI trigger is level */
 326                 trigger = 3;
 327
 328         if (polarity == 0)      /* compatible SCI polarity is low */
 329                 polarity = 3;
 330
 331         /* Command-line over-ride via acpi_sci= */
 332         if (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK)
 333                 trigger = (acpi_sci_flags & ACPI_MADT_TRIGGER_MASK) >> 2;
 334
 335         if (acpi_sci_flags & ACPI_MADT_POLARITY_MASK)
 336                 polarity = acpi_sci_flags & ACPI_MADT_POLARITY_MASK;
 337
 338         /*
 339          * mp_config_acpi_legacy_irqs() already setup IRQs < 16
 340          * If GSI is < 16, this will update its flags,
 341          * else it will create a new mp_irqs[] entry.
 342          */
 343         mp_override_legacy_irq(gsi, polarity, trigger, gsi);
 344
 345         /*
 346          * stash over-ride to indicate we've been here
 347          * and for later update of acpi_gbl_FADT
 348          */
 349         acpi_sci_override_gsi = gsi;
 350         return;
 351 }
 352
 353 static int __init
 354 acpi_parse_int_src_ovr(struct acpi_subtable_header * header,
 355                        const unsigned long end)
 356 {
 357         struct acpi_madt_interrupt_override *intsrc = NULL;
 358
 359         intsrc = (struct acpi_madt_interrupt_override *)header;
 360
 361         if (BAD_MADT_ENTRY(intsrc, end))
 362                 return -EINVAL;
 363
 364         acpi_table_print_madt_entry(header);
 365
 366         if (intsrc->source_irq == acpi_gbl_FADT.sci_interrupt) {
 367                 acpi_sci_ioapic_setup(intsrc->global_irq,
 368                                       intsrc->inti_flags & ACPI_MADT_POLARITY_MASK,
 369                                       (intsrc->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2);
 370                 return 0;
 371         }
 372
 373         if (acpi_skip_timer_override &&
 374             intsrc->source_irq == 0 && intsrc->global_irq == 2) {
 375                 printk(PREFIX "BIOS IRQ0 pin2 override ignored.\n");
 376                 return 0;
 377         }
 378
 379         mp_override_legacy_irq(intsrc->source_irq,
 380                                 intsrc->inti_flags & ACPI_MADT_POLARITY_MASK,
 381                                 (intsrc->inti_flags & ACPI_MADT_TRIGGER_MASK) >> 2,
 382                                 intsrc->global_irq);
 383
 384         return 0;
 385 }
 386
 387 static int __init
 388 acpi_parse_nmi_src(struct acpi_subtable_header * header, const unsigned long end)
 389 {
 390         struct acpi_madt_nmi_source *nmi_src = NULL;
 391
 392         nmi_src = (struct acpi_madt_nmi_source *)header;
 393
 394         if (BAD_MADT_ENTRY(nmi_src, end))
 395                 return -EINVAL;
 396
 397         acpi_table_print_madt_entry(header);
 398
 399         /* TBD: Support nimsrc entries? */
 400
 401         return 0;
 402 }
 403
 404 #endif                          /* CONFIG_X86_IO_APIC */
 405
 406 /*
 407  * acpi_pic_sci_set_trigger()
 408  *
 409  * use ELCR to set PIC-mode trigger type for SCI
 410  *
 411  * If a PIC-mode SCI is not recognized or gives spurious IRQ7's
 412  * it may require Edge Trigger -- use "acpi_sci=edge"
 413  *
 414  * Port 0x4d0-4d1 are ECLR1 and ECLR2, the Edge/Level Control Registers
 415  * for the 8259 PIC.  bit[n] = 1 means irq[n] is Level, otherwise Edge.
 416  * ECLR1 is IRQ's 0-7 (IRQ 0, 1, 2 must be 0)
 417  * ECLR2 is IRQ's 8-15 (IRQ 8, 13 must be 0)
 418  */
 419
 420 void __init acpi_pic_sci_set_trigger(unsigned int irq, u16 trigger)
 421 {
 422         unsigned int mask = 1 << irq;
 423         unsigned int old, new;
 424
 425         /* Real old ELCR mask */
 426         old = inb(0x4d0) | (inb(0x4d1) << 8);
 427
 428         /*
 429          * If we use ACPI to set PCI irq's, then we should clear ELCR
 430          * since we will set it correctly as we enable the PCI irq
 431          * routing.
 432          */
 433         new = acpi_noirq ? old : 0;
 434
 435         /*
 436          * Update SCI information in the ELCR, it isn't in the PCI
 437          * routing tables..
 438          */
 439         switch (trigger) {
 440         case 1:         /* Edge - clear */
 441                 new &= ~mask;
 442                 break;
 443         case 3:         /* Level - set */
 444                 new |= mask;
 445                 break;
 446         }
 447
 448         if (old == new)
 449                 return;
 450
 451         printk(PREFIX "setting ELCR to %04x (from %04x)\n", new, old);
 452         outb(new, 0x4d0);
 453         outb(new >> 8, 0x4d1);
 454 }
 455
 456 int acpi_gsi_to_irq(u32 gsi, unsigned int *irq)
 457 {
 458         *irq = gsi;
 459         return 0;
 460 }
 461
 462 /*
 463  * success: return IRQ number (>=0)
 464  * failure: return < 0
 465  */
 466 int acpi_register_gsi(u32 gsi, int triggering, int polarity)
 467 {
 468         unsigned int irq;
 469         unsigned int plat_gsi = gsi;
 470
 471 #ifdef CONFIG_PCI
 472         /*
 473          * Make sure all (legacy) PCI IRQs are set as level-triggered.
 474          */
 475         if (acpi_irq_model == ACPI_IRQ_MODEL_PIC) {
 476                 extern void eisa_set_level_irq(unsigned int irq);
 477
 478                 if (triggering == ACPI_LEVEL_SENSITIVE)
 479                         eisa_set_level_irq(gsi);
 480         }
 481 #endif
 482
 483 #ifdef CONFIG_X86_IO_APIC
 484         if (acpi_irq_model == ACPI_IRQ_MODEL_IOAPIC) {
 485                 plat_gsi = mp_register_gsi(gsi, triggering, polarity);
 486         }
 487 #endif
 488         acpi_gsi_to_irq(plat_gsi, &irq);
 489         return irq;
 490 }
 491
 492 EXPORT_SYMBOL(acpi_register_gsi);
 493
 494 /*
 495  *  ACPI based hotplug support for CPU
 496  */
 497 #ifdef CONFIG_ACPI_HOTPLUG_CPU
 498 int acpi_map_lsapic(acpi_handle handle, int *pcpu)
 499 {
 500         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 501         union acpi_object *obj;
 502         struct acpi_madt_local_apic *lapic;
 503         cpumask_t tmp_map, new_map;
 504         u8 physid;
 505         int cpu;
 506
 507         if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
 508                 return -EINVAL;
 509
 510         if (!buffer.length || !buffer.pointer)
 511                 return -EINVAL;
 512
 513         obj = buffer.pointer;
 514         if (obj->type != ACPI_TYPE_BUFFER ||
 515             obj->buffer.length < sizeof(*lapic)) {
 516                 kfree(buffer.pointer);
 517                 return -EINVAL;
 518         }
 519
 520         lapic = (struct acpi_madt_local_apic *)obj->buffer.pointer;
 521
 522         if (lapic->header.type != ACPI_MADT_TYPE_LOCAL_APIC ||
 523             !(lapic->lapic_flags & ACPI_MADT_ENABLED)) {
 524                 kfree(buffer.pointer);
 525                 return -EINVAL;
 526         }
 527
 528         physid = lapic->id;
 529
 530         kfree(buffer.pointer);
 531         buffer.length = ACPI_ALLOCATE_BUFFER;
 532         buffer.pointer = NULL;
 533
 534         tmp_map = cpu_present_map;
 535         mp_register_lapic(physid, lapic->lapic_flags & ACPI_MADT_ENABLED);
 536
 537         /*
 538          * If mp_register_lapic successfully generates a new logical cpu
 539          * number, then the following will get us exactly what was mapped
 540          */
 541         cpus_andnot(new_map, cpu_present_map, tmp_map);
 542         if (cpus_empty(new_map)) {
 543                 printk ("Unable to map lapic to logical cpu number\n");
 544                 return -EINVAL;
 545         }
 546
 547         cpu = first_cpu(new_map);
 548
 549         *pcpu = cpu;
 550         return 0;
 551 }
 552
 553 EXPORT_SYMBOL(acpi_map_lsapic);
 554
 555 int acpi_unmap_lsapic(int cpu)
 556 {
 557         x86_cpu_to_apicid[cpu] = -1;
 558         cpu_clear(cpu, cpu_present_map);
 559         num_processors--;
 560
 561         return (0);
 562 }
 563
 564 EXPORT_SYMBOL(acpi_unmap_lsapic);
 565 #endif                          /* CONFIG_ACPI_HOTPLUG_CPU */
 566
 567 int acpi_register_ioapic(acpi_handle handle, u64 phys_addr, u32 gsi_base)
 568 {
 569         /* TBD */
 570         return -EINVAL;
 571 }
 572
 573 EXPORT_SYMBOL(acpi_register_ioapic);
 574
 575 int acpi_unregister_ioapic(acpi_handle handle, u32 gsi_base)
 576 {
 577         /* TBD */
 578         return -EINVAL;
 579 }
 580
 581 EXPORT_SYMBOL(acpi_unregister_ioapic);
 582
 583 static unsigned long __init
 584 acpi_scan_rsdp(unsigned long start, unsigned long length)
 585 {
 586         unsigned long offset = 0;
 587         unsigned long sig_len = sizeof("RSD PTR ") - 1;
 588
 589         /*
 590          * Scan all 16-byte boundaries of the physical memory region for the
 591          * RSDP signature.
 592          */
 593         for (offset = 0; offset < length; offset += 16) {
 594                 if (strncmp((char *)(phys_to_virt(start) + offset), "RSD PTR ", sig_len))
 595                         continue;
 596                 return (start + offset);
 597         }
 598
 599         return 0;
 600 }
 601
 602 static int __init acpi_parse_sbf(struct acpi_table_header *table)
 603 {
 604         struct acpi_table_boot *sb;
 605
 606         sb = (struct acpi_table_boot *)table;
 607         if (!sb) {
 608                 printk(KERN_WARNING PREFIX "Unable to map SBF\n");
 609                 return -ENODEV;
 610         }
 611
 612         sbf_port = sb->cmos_index;      /* Save CMOS port */
 613
 614         return 0;
 615 }
 616
 617 #ifdef CONFIG_HPET_TIMER
 618
 619 static int __init acpi_parse_hpet(struct acpi_table_header *table)
 620 {
 621         struct acpi_table_hpet *hpet_tbl;
 622         struct resource *hpet_res;
 623         resource_size_t res_start;
 624
 625         hpet_tbl = (struct acpi_table_hpet *)table;
 626         if (!hpet_tbl) {
 627                 printk(KERN_WARNING PREFIX "Unable to map HPET\n");
 628                 return -ENODEV;
 629         }
 630
 631         if (hpet_tbl->address.space_id != ACPI_SPACE_MEM) {
 632                 printk(KERN_WARNING PREFIX "HPET timers must be located in "
 633                        "memory.\n");
 634                 return -1;
 635         }
 636
 637 #define HPET_RESOURCE_NAME_SIZE 9
 638         hpet_res = alloc_bootmem(sizeof(*hpet_res) + HPET_RESOURCE_NAME_SIZE);
 639         if (hpet_res) {
 640                 memset(hpet_res, 0, sizeof(*hpet_res));
 641                 hpet_res->name = (void *)&hpet_res[1];
 642                 hpet_res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 643                 snprintf((char *)hpet_res->name, HPET_RESOURCE_NAME_SIZE,
 644                          "HPET %u", hpet_tbl->sequence);
 645                 hpet_res->end = (1 * 1024) - 1;
 646         }
 647
 648 #ifdef CONFIG_X86_64
 649         vxtime.hpet_address = hpet_tbl->address.address;
 650
 651         printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
 652                 hpet_tbl->id, vxtime.hpet_address);
 653
 654         res_start = vxtime.hpet_address;
 655 #else                          /* X86 */
 656         {
 657                 extern unsigned long hpet_address;
 658
 659                 hpet_address = hpet_tbl->address.address;
 660                 printk(KERN_INFO PREFIX "HPET id: %#x base: %#lx\n",
 661                         hpet_tbl->id, hpet_address);
 662
 663                 res_start = hpet_address;
 664         }
 665 #endif                         /* X86 */
 666
 667         if (hpet_res) {
 668                 hpet_res->start = res_start;
 669                 hpet_res->end += res_start;
 670                 insert_resource(&iomem_resource, hpet_res);
 671         }
 672
 673         return 0;
 674 }
 675 #else
 676 #define acpi_parse_hpet NULL
 677 #endif
 678
 679 #ifdef CONFIG_X86_PM_TIMER
 680 extern u32 pmtmr_ioport;
 681 #endif
 682
 683 static int __init acpi_parse_fadt(struct acpi_table_header *table)
 684 {
 685
 686 #ifdef CONFIG_X86_PM_TIMER
 687         /* detect the location of the ACPI PM Timer */
 688         if (acpi_gbl_FADT.header.revision >= FADT2_REVISION_ID) {
 689                 /* FADT rev. 2 */
 690                 if (acpi_gbl_FADT.xpm_timer_block.space_id !=
 691                     ACPI_ADR_SPACE_SYSTEM_IO)
 692                         return 0;
 693
 694                 pmtmr_ioport = acpi_gbl_FADT.xpm_timer_block.address;
 695                 /*
 696                  * "X" fields are optional extensions to the original V1.0
 697                  * fields, so we must selectively expand V1.0 fields if the
 698                  * corresponding X field is zero.
 699                  */
 700                 if (!pmtmr_ioport)
 701                         pmtmr_ioport = acpi_gbl_FADT.pm_timer_block;
 702         } else {
 703                 /* FADT rev. 1 */
 704                 pmtmr_ioport = acpi_gbl_FADT.pm_timer_block;
 705         }
 706         if (pmtmr_ioport)
 707                 printk(KERN_INFO PREFIX "PM-Timer IO Port: %#x\n",
 708                        pmtmr_ioport);
 709 #endif
 710         return 0;
 711 }
 712
 713 unsigned long __init acpi_find_rsdp(void)
 714 {
 715         unsigned long rsdp_phys = 0;
 716
 717         if (efi_enabled) {
 718                 if (efi.acpi20 != EFI_INVALID_TABLE_ADDR)
 719                         return efi.acpi20;
 720                 else if (efi.acpi != EFI_INVALID_TABLE_ADDR)
 721                         return efi.acpi;
 722         }
 723         /*
 724          * Scan memory looking for the RSDP signature. First search EBDA (low
 725          * memory) paragraphs and then search upper memory (E0000-FFFFF).
 726          */
 727         rsdp_phys = acpi_scan_rsdp(0, 0x400);
 728         if (!rsdp_phys)
 729                 rsdp_phys = acpi_scan_rsdp(0xE0000, 0x20000);
 730
 731         return rsdp_phys;
 732 }
 733
 734 #ifdef  CONFIG_X86_LOCAL_APIC
 735 /*
 736  * Parse LAPIC entries in MADT
 737  * returns 0 on success, < 0 on error
 738  */
 739 static int __init acpi_parse_madt_lapic_entries(void)
 740 {
 741         int count;
 742
 743         if (!cpu_has_apic)
 744                 return -ENODEV;
 745
 746         /*
 747          * Note that the LAPIC address is obtained from the MADT (32-bit value)
 748          * and (optionally) overriden by a LAPIC_ADDR_OVR entry (64-bit value).
 749          */
 750
 751         count =
 752             acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_OVERRIDE,
 753                                   acpi_parse_lapic_addr_ovr, 0);
 754         if (count < 0) {
 755                 printk(KERN_ERR PREFIX
 756                        "Error parsing LAPIC address override entry\n");
 757                 return count;
 758         }
 759
 760         mp_register_lapic_address(acpi_lapic_addr);
 761
 762         count = acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC, acpi_parse_lapic,
 763                                       MAX_APICS);
 764         if (!count) {
 765                 printk(KERN_ERR PREFIX "No LAPIC entries present\n");
 766                 /* TBD: Cleanup to allow fallback to MPS */
 767                 return -ENODEV;
 768         } else if (count < 0) {
 769                 printk(KERN_ERR PREFIX "Error parsing LAPIC entry\n");
 770                 /* TBD: Cleanup to allow fallback to MPS */
 771                 return count;
 772         }
 773
 774         count =
 775             acpi_table_parse_madt(ACPI_MADT_TYPE_LOCAL_APIC_NMI, acpi_parse_lapic_nmi, 0);
 776         if (count < 0) {
 777                 printk(KERN_ERR PREFIX "Error parsing LAPIC NMI entry\n");
 778                 /* TBD: Cleanup to allow fallback to MPS */
 779                 return count;
 780         }
 781         return 0;
 782 }
 783 #endif                          /* CONFIG_X86_LOCAL_APIC */
 784
 785 #ifdef  CONFIG_X86_IO_APIC
 786 /*
 787  * Parse IOAPIC related entries in MADT
 788  * returns 0 on success, < 0 on error
 789  */
 790 static int __init acpi_parse_madt_ioapic_entries(void)
 791 {
 792         int count;
 793
 794         /*
 795          * ACPI interpreter is required to complete interrupt setup,
 796          * so if it is off, don't enumerate the io-apics with ACPI.
 797          * If MPS is present, it will handle them,
 798          * otherwise the system will stay in PIC mode
 799          */
 800         if (acpi_disabled || acpi_noirq) {
 801                 return -ENODEV;
 802         }
 803
 804         if (!cpu_has_apic)
 805                 return -ENODEV;
 806
 807         /*
 808          * if "noapic" boot option, don't look for IO-APICs
 809          */
 810         if (skip_ioapic_setup) {
 811                 printk(KERN_INFO PREFIX "Skipping IOAPIC probe "
 812                        "due to 'noapic' option.\n");
 813                 return -ENODEV;
 814         }
 815
 816         count =
 817             acpi_table_parse_madt(ACPI_MADT_TYPE_IO_APIC, acpi_parse_ioapic,
 818                                   MAX_IO_APICS);
 819         if (!count) {
 820                 printk(KERN_ERR PREFIX "No IOAPIC entries present\n");
 821                 return -ENODEV;
 822         } else if (count < 0) {
 823                 printk(KERN_ERR PREFIX "Error parsing IOAPIC entry\n");
 824                 return count;
 825         }
 826
 827         count =
 828             acpi_table_parse_madt(ACPI_MADT_TYPE_INTERRUPT_OVERRIDE, acpi_parse_int_src_ovr,
 829                                   NR_IRQ_VECTORS);
 830         if (count < 0) {
 831                 printk(KERN_ERR PREFIX
 832                        "Error parsing interrupt source overrides entry\n");
 833                 /* TBD: Cleanup to allow fallback to MPS */
 834                 return count;
 835         }
 836
 837         /*
 838          * If BIOS did not supply an INT_SRC_OVR for the SCI
 839          * pretend we got one so we can set the SCI flags.
 840          */
 841         if (!acpi_sci_override_gsi)
 842                 acpi_sci_ioapic_setup(acpi_gbl_FADT.sci_interrupt, 0, 0);
 843
 844         /* Fill in identity legacy mapings where no override */
 845         mp_config_acpi_legacy_irqs();
 846
 847         count =
 848             acpi_table_parse_madt(ACPI_MADT_TYPE_NMI_SOURCE, acpi_parse_nmi_src,
 849                                   NR_IRQ_VECTORS);
 850         if (count < 0) {
 851                 printk(KERN_ERR PREFIX "Error parsing NMI SRC entry\n");
 852                 /* TBD: Cleanup to allow fallback to MPS */
 853                 return count;
 854         }
 855
 856         return 0;
 857 }
 858 #else
 859 static inline int acpi_parse_madt_ioapic_entries(void)
 860 {
 861         return -1;
 862 }
 863 #endif  /* !CONFIG_X86_IO_APIC */
 864
 865 static void __init acpi_process_madt(void)
 866 {
 867 #ifdef CONFIG_X86_LOCAL_APIC
 868         int error;
 869
 870         if (!acpi_table_parse(ACPI_SIG_MADT, acpi_parse_madt)) {
 871
 872                 /*
 873                  * Parse MADT LAPIC entries
 874                  */
 875                 error = acpi_parse_madt_lapic_entries();
 876                 if (!error) {
 877                         acpi_lapic = 1;
 878
 879 #ifdef CONFIG_X86_GENERICARCH
 880                         generic_bigsmp_probe();
 881 #endif
 882                         /*
 883                          * Parse MADT IO-APIC entries
 884                          */
 885                         error = acpi_parse_madt_ioapic_entries();
 886                         if (!error) {
 887                                 acpi_irq_model = ACPI_IRQ_MODEL_IOAPIC;
 888                                 acpi_irq_balance_set(NULL);
 889                                 acpi_ioapic = 1;
 890
 891                                 smp_found_config = 1;
 892                                 clustered_apic_check();
 893                         }
 894                 }
 895                 if (error == -EINVAL) {
 896                         /*
 897                          * Dell Precision Workstation 410, 610 come here.
 898                          */
 899                         printk(KERN_ERR PREFIX
 900                                "Invalid BIOS MADT, disabling ACPI\n");
 901                         disable_acpi();
 902                 }
 903         }
 904 #endif
 905         return;
 906 }
 907
 908 #ifdef __i386__
 909
 910 static int __init disable_acpi_irq(struct dmi_system_id *d)
 911 {
 912         if (!acpi_force) {
 913                 printk(KERN_NOTICE "%s detected: force use of acpi=noirq\n",
 914                        d->ident);
 915                 acpi_noirq_set();
 916         }
 917         return 0;
 918 }
 919
 920 static int __init disable_acpi_pci(struct dmi_system_id *d)
 921 {
 922         if (!acpi_force) {
 923                 printk(KERN_NOTICE "%s detected: force use of pci=noacpi\n",
 924                        d->ident);
 925                 acpi_disable_pci();
 926         }
 927         return 0;
 928 }
 929
 930 static int __init dmi_disable_acpi(struct dmi_system_id *d)
 931 {
 932         if (!acpi_force) {
 933                 printk(KERN_NOTICE "%s detected: acpi off\n", d->ident);
 934                 disable_acpi();
 935         } else {
 936                 printk(KERN_NOTICE
 937                        "Warning: DMI blacklist says broken, but acpi forced\n");
 938         }
 939         return 0;
 940 }
 941
 942 /*
 943  * Limit ACPI to CPU enumeration for HT
 944  */
 945 static int __init force_acpi_ht(struct dmi_system_id *d)
 946 {
 947         if (!acpi_force) {
 948                 printk(KERN_NOTICE "%s detected: force use of acpi=ht\n",
 949                        d->ident);
 950                 disable_acpi();
 951                 acpi_ht = 1;
 952         } else {
 953                 printk(KERN_NOTICE
 954                        "Warning: acpi=force overrules DMI blacklist: acpi=ht\n");
 955         }
 956         return 0;
 957 }
 958
 959 /*
 960  * If your system is blacklisted here, but you find that acpi=force
 961  * works for you, please contact acpi-devel@sourceforge.net
 962  */
 963 static struct dmi_system_id __initdata acpi_dmi_table[] = {
 964         /*
 965          * Boxes that need ACPI disabled
 966          */
 967         {
 968          .callback = dmi_disable_acpi,
 969          .ident = "IBM Thinkpad",
 970          .matches = {
 971                      DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
 972                      DMI_MATCH(DMI_BOARD_NAME, "2629H1G"),
 973                      },
 974          },
 975
 976         /*
 977          * Boxes that need acpi=ht
 978          */
 979         {
 980          .callback = force_acpi_ht,
 981          .ident = "FSC Primergy T850",
 982          .matches = {
 983                      DMI_MATCH(DMI_SYS_VENDOR, "FUJITSU SIEMENS"),
 984                      DMI_MATCH(DMI_PRODUCT_NAME, "PRIMERGY T850"),
 985                      },
 986          },
 987         {
 988          .callback = force_acpi_ht,
 989          .ident = "DELL GX240",
 990          .matches = {
 991                      DMI_MATCH(DMI_BOARD_VENDOR, "Dell Computer Corporation"),
 992                      DMI_MATCH(DMI_BOARD_NAME, "OptiPlex GX240"),
 993                      },
 994          },
 995         {
 996          .callback = force_acpi_ht,
 997          .ident = "HP VISUALIZE NT Workstation",
 998          .matches = {
 999                      DMI_MATCH(DMI_BOARD_VENDOR, "Hewlett-Packard"),
1000                      DMI_MATCH(DMI_PRODUCT_NAME, "HP VISUALIZE NT Workstation"),
1001                      },
1002          },
1003         {
1004          .callback = force_acpi_ht,
1005          .ident = "Compaq Workstation W8000",
1006          .matches = {
1007                      DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
1008                      DMI_MATCH(DMI_PRODUCT_NAME, "Workstation W8000"),
1009                      },
1010          },
1011         {
1012          .callback = force_acpi_ht,
1013          .ident = "ASUS P4B266",
1014          .matches = {
1015                      DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
1016                      DMI_MATCH(DMI_BOARD_NAME, "P4B266"),
1017                      },
1018          },
1019         {
1020          .callback = force_acpi_ht,
1021          .ident = "ASUS P2B-DS",
1022          .matches = {
1023                      DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
1024                      DMI_MATCH(DMI_BOARD_NAME, "P2B-DS"),
1025                      },
1026          },
1027         {
1028          .callback = force_acpi_ht,
1029          .ident = "ASUS CUR-DLS",
1030          .matches = {
1031                      DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
1032                      DMI_MATCH(DMI_BOARD_NAME, "CUR-DLS"),
1033                      },
1034          },
1035         {
1036          .callback = force_acpi_ht,
1037          .ident = "ABIT i440BX-W83977",
1038          .matches = {
1039                      DMI_MATCH(DMI_BOARD_VENDOR, "ABIT <http://www.abit.com>"),
1040                      DMI_MATCH(DMI_BOARD_NAME, "i440BX-W83977 (BP6)"),
1041                      },
1042          },
1043         {
1044          .callback = force_acpi_ht,
1045          .ident = "IBM Bladecenter",
1046          .matches = {
1047                      DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1048                      DMI_MATCH(DMI_BOARD_NAME, "IBM eServer BladeCenter HS20"),
1049                      },
1050          },
1051         {
1052          .callback = force_acpi_ht,
1053          .ident = "IBM eServer xSeries 360",
1054          .matches = {
1055                      DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1056                      DMI_MATCH(DMI_BOARD_NAME, "eServer xSeries 360"),
1057                      },
1058          },
1059         {
1060          .callback = force_acpi_ht,
1061          .ident = "IBM eserver xSeries 330",
1062          .matches = {
1063                      DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1064                      DMI_MATCH(DMI_BOARD_NAME, "eserver xSeries 330"),
1065                      },
1066          },
1067         {
1068          .callback = force_acpi_ht,
1069          .ident = "IBM eserver xSeries 440",
1070          .matches = {
1071                      DMI_MATCH(DMI_BOARD_VENDOR, "IBM"),
1072                      DMI_MATCH(DMI_PRODUCT_NAME, "eserver xSeries 440"),
1073                      },
1074          },
1075
1076         /*
1077          * Boxes that need ACPI PCI IRQ routing disabled
1078          */
1079         {
1080          .callback = disable_acpi_irq,
1081          .ident = "ASUS A7V",
1082          .matches = {
1083                      DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC"),
1084                      DMI_MATCH(DMI_BOARD_NAME, "<A7V>"),
1085                      /* newer BIOS, Revision 1011, does work */
1086                      DMI_MATCH(DMI_BIOS_VERSION,
1087                                "ASUS A7V ACPI BIOS Revision 1007"),
1088                      },
1089          },
1090
1091         /*
1092          * Boxes that need ACPI PCI IRQ routing and PCI scan disabled
1093          */
1094         {                       /* _BBN 0 bug */
1095          .callback = disable_acpi_pci,
1096          .ident = "ASUS PR-DLS",
1097          .matches = {
1098                      DMI_MATCH(DMI_BOARD_VENDOR, "ASUSTeK Computer INC."),
1099                      DMI_MATCH(DMI_BOARD_NAME, "PR-DLS"),
1100                      DMI_MATCH(DMI_BIOS_VERSION,
1101                                "ASUS PR-DLS ACPI BIOS Revision 1010"),
1102                      DMI_MATCH(DMI_BIOS_DATE, "03/21/2003")
1103                      },
1104          },
1105         {
1106          .callback = disable_acpi_pci,
1107          .ident = "Acer TravelMate 36x Laptop",
1108          .matches = {
1109                      DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
1110                      DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 360"),
1111                      },
1112          },
1113         {}
1114 };
1115
1116 #endif                          /* __i386__ */
1117
1118 /*
1119  * acpi_boot_table_init() and acpi_boot_init()
1120  *  called from setup_arch(), always.
1121  *      1. checksums all tables
1122  *      2. enumerates lapics
1123  *      3. enumerates io-apics
1124  *
1125  * acpi_table_init() is separate to allow reading SRAT without
1126  * other side effects.
1127  *
1128  * side effects of acpi_boot_init:
1129  *      acpi_lapic = 1 if LAPIC found
1130  *      acpi_ioapic = 1 if IOAPIC found
1131  *      if (acpi_lapic && acpi_ioapic) smp_found_config = 1;
1132  *      if acpi_blacklisted() acpi_disabled = 1;
1133  *      acpi_irq_model=...
1134  *      ...
1135  *
1136  * return value: (currently ignored)
1137  *      0: success
1138  *      !0: failure
1139  */
1140
1141 int __init acpi_boot_table_init(void)
1142 {
1143         int error;
1144
1145 #ifdef __i386__
1146         dmi_check_system(acpi_dmi_table);
1147 #endif
1148
1149         /*
1150          * If acpi_disabled, bail out
1151          * One exception: acpi=ht continues far enough to enumerate LAPICs
1152          */
1153         if (acpi_disabled && !acpi_ht)
1154                 return 1;
1155
1156         /*
1157          * Initialize the ACPI boot-time table parser.
1158          */
1159         error = acpi_table_init();
1160         if (error) {
1161                 disable_acpi();
1162                 return error;
1163         }
1164
1165         acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);
1166
1167         /*
1168          * blacklist may disable ACPI entirely
1169          */
1170         error = acpi_blacklisted();
1171         if (error) {
1172                 if (acpi_force) {
1173                         printk(KERN_WARNING PREFIX "acpi=force override\n");
1174                 } else {
1175                         printk(KERN_WARNING PREFIX "Disabling ACPI support\n");
1176                         disable_acpi();
1177                         return error;
1178                 }
1179         }
1180
1181         return 0;
1182 }
1183
1184 int __init acpi_boot_init(void)
1185 {
1186         /*
1187          * If acpi_disabled, bail out
1188          * One exception: acpi=ht continues far enough to enumerate LAPICs
1189          */
1190         if (acpi_disabled && !acpi_ht)
1191                 return 1;
1192
1193         acpi_table_parse(ACPI_SIG_BOOT, acpi_parse_sbf);
1194
1195         /*
1196          * set sci_int and PM timer address
1197          */
1198         acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt);
1199
1200         /*
1201          * Process the Multiple APIC Description Table (MADT), if present
1202          */
1203         acpi_process_madt();
1204
1205         acpi_table_parse(ACPI_SIG_HPET, acpi_parse_hpet);
1206
1207         return 0;
1208 }
1209
1210 static int __init parse_acpi(char *arg)
1211 {
1212         if (!arg)
1213                 return -EINVAL;
1214
1215         /* "acpi=off" disables both ACPI table parsing and interpreter */
1216         if (strcmp(arg, "off") == 0) {
1217                 disable_acpi();
1218         }
1219         /* acpi=force to over-ride black-list */
1220         else if (strcmp(arg, "force") == 0) {
1221                 acpi_force = 1;
1222                 acpi_ht = 1;
1223                 acpi_disabled = 0;
1224         }
1225         /* acpi=strict disables out-of-spec workarounds */
1226         else if (strcmp(arg, "strict") == 0) {
1227                 acpi_strict = 1;
1228         }
1229         /* Limit ACPI just to boot-time to enable HT */
1230         else if (strcmp(arg, "ht") == 0) {
1231                 if (!acpi_force)
1232                         disable_acpi();
1233                 acpi_ht = 1;
1234         }
1235         /* "acpi=noirq" disables ACPI interrupt routing */
1236         else if (strcmp(arg, "noirq") == 0) {
1237                 acpi_noirq_set();
1238         } else {
1239                 /* Core will printk when we return error. */
1240                 return -EINVAL;
1241         }
1242         return 0;
1243 }
1244 early_param("acpi", parse_acpi);
1245
1246 /* FIXME: Using pci= for an ACPI parameter is a travesty. */
1247 static int __init parse_pci(char *arg)
1248 {
1249         if (arg && strcmp(arg, "noacpi") == 0)
1250                 acpi_disable_pci();
1251         return 0;
1252 }
1253 early_param("pci", parse_pci);
1254
1255 #ifdef CONFIG_X86_IO_APIC
1256 static int __init parse_acpi_skip_timer_override(char *arg)
1257 {
1258         acpi_skip_timer_override = 1;
1259         return 0;
1260 }
1261 early_param("acpi_skip_timer_override", parse_acpi_skip_timer_override);
1262
1263 static int __init parse_acpi_use_timer_override(char *arg)
1264 {
1265         acpi_use_timer_override = 1;
1266         return 0;
1267 }
1268 early_param("acpi_use_timer_override", parse_acpi_use_timer_override);
1269 #endif /* CONFIG_X86_IO_APIC */
1270
1271 static int __init setup_acpi_sci(char *s)
1272 {
1273         if (!s)
1274                 return -EINVAL;
1275         if (!strcmp(s, "edge"))
1276                 acpi_sci_flags =  ACPI_MADT_TRIGGER_EDGE |
1277                         (acpi_sci_flags & ~ACPI_MADT_TRIGGER_MASK);
1278         else if (!strcmp(s, "level"))
1279                 acpi_sci_flags = ACPI_MADT_TRIGGER_LEVEL |
1280                         (acpi_sci_flags & ~ACPI_MADT_TRIGGER_MASK);
1281         else if (!strcmp(s, "high"))
1282                 acpi_sci_flags = ACPI_MADT_POLARITY_ACTIVE_HIGH |
1283                         (acpi_sci_flags & ~ACPI_MADT_POLARITY_MASK);
1284         else if (!strcmp(s, "low"))
1285                 acpi_sci_flags = ACPI_MADT_POLARITY_ACTIVE_LOW |
1286                         (acpi_sci_flags & ~ACPI_MADT_POLARITY_MASK);
1287         else
1288                 return -EINVAL;
1289         return 0;
1290 }
1291 early_param("acpi_sci", setup_acpi_sci);
1292
1293 int __acpi_acquire_global_lock(unsigned int *lock)
1294 {
1295         unsigned int old, new, val;
1296         do {
1297                 old = *lock;
1298                 new = (((old & ~0x3) + 2) + ((old >> 1) & 0x1));
1299                 val = cmpxchg(lock, old, new);
1300         } while (unlikely (val != old));
1301         return (new < 3) ? -1 : 0;
1302 }
1303
1304 int __acpi_release_global_lock(unsigned int *lock)
1305 {
1306         unsigned int old, new, val;
1307         do {
1308                 old = *lock;
1309                 new = old & ~0x3;
1310                 val = cmpxchg(lock, old, new);
1311         } while (unlikely (val != old));
1312         return old & 0x1;
1313 }