drivers/acpi/processor_idle.c

   1 /*
   2  * processor_idle - idle state submodule to the ACPI processor driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  10  *                      - Added support for C3 on SMP
  11  *
  12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU General Public License as published by
  16  *  the Free Software Foundation; either version 2 of the License, or (at
  17  *  your option) any later version.
  18  *
  19  *  This program is distributed in the hope that it will be useful, but
  20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22  *  General Public License for more details.
  23  *
  24  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  25  */
  26 #define pr_fmt(fmt) "ACPI: " fmt
  27
  28 #include <linux/module.h>
  29 #include <linux/acpi.h>
  30 #include <linux/dmi.h>
  31 #include <linux/sched.h>       /* need_resched() */
  32 #include <linux/tick.h>
  33 #include <linux/cpuidle.h>
  34 #include <linux/cpu.h>
  35 #include <acpi/processor.h>
  36
  37 /*
  38  * Include the apic definitions for x86 to have the APIC timer related defines
  39  * available also for UP (on SMP it gets magically included via linux/smp.h).
  40  * asm/acpi.h is not an option, as it would require more include magic. Also
  41  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  42  */
  43 #ifdef CONFIG_X86
  44 #include <asm/apic.h>
  45 #endif
  46
  47 #define ACPI_PROCESSOR_CLASS            "processor"
  48 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  49 ACPI_MODULE_NAME("processor_idle");
  50
  51 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
  52
  53 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  54 module_param(max_cstate, uint, 0000);
  55 static unsigned int nocst __read_mostly;
  56 module_param(nocst, uint, 0000);
  57 static int bm_check_disable __read_mostly;
  58 module_param(bm_check_disable, uint, 0000);
  59
  60 static unsigned int latency_factor __read_mostly = 2;
  61 module_param(latency_factor, uint, 0644);
  62
  63 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  64
  65 struct cpuidle_driver acpi_idle_driver = {
  66         .name =         "acpi_idle",
  67         .owner =        THIS_MODULE,
  68 };
  69
  70 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  71 static
  72 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  73
  74 static int disabled_by_idle_boot_param(void)
  75 {
  76         return boot_option_idle_override == IDLE_POLL ||
  77                 boot_option_idle_override == IDLE_HALT;
  78 }
  79
  80 /*
  81  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  82  * For now disable this. Probably a bug somewhere else.
  83  *
  84  * To skip this limit, boot/load with a large max_cstate limit.
  85  */
  86 static int set_max_cstate(const struct dmi_system_id *id)
  87 {
  88         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  89                 return 0;
  90
  91         pr_notice("%s detected - limiting to C%ld max_cstate."
  92                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  93                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  94
  95         max_cstate = (long)id->driver_data;
  96
  97         return 0;
  98 }
  99
 100 static const struct dmi_system_id processor_power_dmi_table[] = {
 101         { set_max_cstate, "Clevo 5600D", {
 102           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 103           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 104          (void *)2},
 105         { set_max_cstate, "Pavilion zv5000", {
 106           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 107           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 108          (void *)1},
 109         { set_max_cstate, "Asus L8400B", {
 110           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 111           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 112          (void *)1},
 113         {},
 114 };
 115
 116
 117 /*
 118  * Callers should disable interrupts before the call and enable
 119  * interrupts after return.
 120  */
 121 static void __cpuidle acpi_safe_halt(void)
 122 {
 123         if (!tif_need_resched()) {
 124                 safe_halt();
 125                 local_irq_disable();
 126         }
 127 }
 128
 129 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 130
 131 /*
 132  * Some BIOS implementations switch to C3 in the published C2 state.
 133  * This seems to be a common problem on AMD boxen, but other vendors
 134  * are affected too. We pick the most conservative approach: we assume
 135  * that the local APIC stops in both C2 and C3.
 136  */
 137 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 138                                    struct acpi_processor_cx *cx)
 139 {
 140         struct acpi_processor_power *pwr = &pr->power;
 141         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 142
 143         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 144                 return;
 145
 146         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
 147                 type = ACPI_STATE_C1;
 148
 149         /*
 150          * Check, if one of the previous states already marked the lapic
 151          * unstable
 152          */
 153         if (pwr->timer_broadcast_on_state < state)
 154                 return;
 155
 156         if (cx->type >= type)
 157                 pr->power.timer_broadcast_on_state = state;
 158 }
 159
 160 static void __lapic_timer_propagate_broadcast(void *arg)
 161 {
 162         struct acpi_processor *pr = (struct acpi_processor *) arg;
 163
 164         if (pr->power.timer_broadcast_on_state < INT_MAX)
 165                 tick_broadcast_enable();
 166         else
 167                 tick_broadcast_disable();
 168 }
 169
 170 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 171 {
 172         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 173                                  (void *)pr, 1);
 174 }
 175
 176 /* Power(C) State timer broadcast control */
 177 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 178                                        struct acpi_processor_cx *cx,
 179                                        int broadcast)
 180 {
 181         int state = cx - pr->power.states;
 182
 183         if (state >= pr->power.timer_broadcast_on_state) {
 184                 if (broadcast)
 185                         tick_broadcast_enter();
 186                 else
 187                         tick_broadcast_exit();
 188         }
 189 }
 190
 191 #else
 192
 193 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 194                                    struct acpi_processor_cx *cstate) { }
 195 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 196 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 197                                        struct acpi_processor_cx *cx,
 198                                        int broadcast)
 199 {
 200 }
 201
 202 #endif
 203
 204 #if defined(CONFIG_X86)
 205 static void tsc_check_state(int state)
 206 {
 207         switch (boot_cpu_data.x86_vendor) {
 208         case X86_VENDOR_AMD:
 209         case X86_VENDOR_INTEL:
 210                 /*
 211                  * AMD Fam10h TSC will tick in all
 212                  * C/P/S0/S1 states when this bit is set.
 213                  */
 214                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 215                         return;
 216
 217                 /*FALL THROUGH*/
 218         default:
 219                 /* TSC could halt in idle, so notify users */
 220                 if (state > ACPI_STATE_C1)
 221                         mark_tsc_unstable("TSC halts in idle");
 222         }
 223 }
 224 #else
 225 static void tsc_check_state(int state) { return; }
 226 #endif
 227
 228 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 229 {
 230
 231         if (!pr->pblk)
 232                 return -ENODEV;
 233
 234         /* if info is obtained from pblk/fadt, type equals state */
 235         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 236         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 237
 238 #ifndef CONFIG_HOTPLUG_CPU
 239         /*
 240          * Check for P_LVL2_UP flag before entering C2 and above on
 241          * an SMP system.
 242          */
 243         if ((num_online_cpus() > 1) &&
 244             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 245                 return -ENODEV;
 246 #endif
 247
 248         /* determine C2 and C3 address from pblk */
 249         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 250         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 251
 252         /* determine latencies from FADT */
 253         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 254         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 255
 256         /*
 257          * FADT specified C2 latency must be less than or equal to
 258          * 100 microseconds.
 259          */
 260         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 261                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 262                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 263                 /* invalidate C2 */
 264                 pr->power.states[ACPI_STATE_C2].address = 0;
 265         }
 266
 267         /*
 268          * FADT supplied C3 latency must be less than or equal to
 269          * 1000 microseconds.
 270          */
 271         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 272                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 273                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 274                 /* invalidate C3 */
 275                 pr->power.states[ACPI_STATE_C3].address = 0;
 276         }
 277
 278         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 279                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 280                           pr->power.states[ACPI_STATE_C2].address,
 281                           pr->power.states[ACPI_STATE_C3].address));
 282
 283         return 0;
 284 }
 285
 286 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 287 {
 288         if (!pr->power.states[ACPI_STATE_C1].valid) {
 289                 /* set the first C-State to C1 */
 290                 /* all processors need to support C1 */
 291                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 292                 pr->power.states[ACPI_STATE_C1].valid = 1;
 293                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 294         }
 295         /* the C0 state only exists as a filler in our array */
 296         pr->power.states[ACPI_STATE_C0].valid = 1;
 297         return 0;
 298 }
 299
 300 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 301 {
 302         acpi_status status;
 303         u64 count;
 304         int current_count;
 305         int i, ret = 0;
 306         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 307         union acpi_object *cst;
 308
 309         if (nocst)
 310                 return -ENODEV;
 311
 312         current_count = 0;
 313
 314         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 315         if (ACPI_FAILURE(status)) {
 316                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 317                 return -ENODEV;
 318         }
 319
 320         cst = buffer.pointer;
 321
 322         /* There must be at least 2 elements */
 323         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 324                 pr_err("not enough elements in _CST\n");
 325                 ret = -EFAULT;
 326                 goto end;
 327         }
 328
 329         count = cst->package.elements[0].integer.value;
 330
 331         /* Validate number of power states. */
 332         if (count < 1 || count != cst->package.count - 1) {
 333                 pr_err("count given by _CST is not valid\n");
 334                 ret = -EFAULT;
 335                 goto end;
 336         }
 337
 338         /* Tell driver that at least _CST is supported. */
 339         pr->flags.has_cst = 1;
 340
 341         for (i = 1; i <= count; i++) {
 342                 union acpi_object *element;
 343                 union acpi_object *obj;
 344                 struct acpi_power_register *reg;
 345                 struct acpi_processor_cx cx;
 346
 347                 memset(&cx, 0, sizeof(cx));
 348
 349                 element = &(cst->package.elements[i]);
 350                 if (element->type != ACPI_TYPE_PACKAGE)
 351                         continue;
 352
 353                 if (element->package.count != 4)
 354                         continue;
 355
 356                 obj = &(element->package.elements[0]);
 357
 358                 if (obj->type != ACPI_TYPE_BUFFER)
 359                         continue;
 360
 361                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 362
 363                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 364                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 365                         continue;
 366
 367                 /* There should be an easy way to extract an integer... */
 368                 obj = &(element->package.elements[1]);
 369                 if (obj->type != ACPI_TYPE_INTEGER)
 370                         continue;
 371
 372                 cx.type = obj->integer.value;
 373                 /*
 374                  * Some buggy BIOSes won't list C1 in _CST -
 375                  * Let acpi_processor_get_power_info_default() handle them later
 376                  */
 377                 if (i == 1 && cx.type != ACPI_STATE_C1)
 378                         current_count++;
 379
 380                 cx.address = reg->address;
 381                 cx.index = current_count + 1;
 382
 383                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 384                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 385                         if (acpi_processor_ffh_cstate_probe
 386                                         (pr->id, &cx, reg) == 0) {
 387                                 cx.entry_method = ACPI_CSTATE_FFH;
 388                         } else if (cx.type == ACPI_STATE_C1) {
 389                                 /*
 390                                  * C1 is a special case where FIXED_HARDWARE
 391                                  * can be handled in non-MWAIT way as well.
 392                                  * In that case, save this _CST entry info.
 393                                  * Otherwise, ignore this info and continue.
 394                                  */
 395                                 cx.entry_method = ACPI_CSTATE_HALT;
 396                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 397                         } else {
 398                                 continue;
 399                         }
 400                         if (cx.type == ACPI_STATE_C1 &&
 401                             (boot_option_idle_override == IDLE_NOMWAIT)) {
 402                                 /*
 403                                  * In most cases the C1 space_id obtained from
 404                                  * _CST object is FIXED_HARDWARE access mode.
 405                                  * But when the option of idle=halt is added,
 406                                  * the entry_method type should be changed from
 407                                  * CSTATE_FFH to CSTATE_HALT.
 408                                  * When the option of idle=nomwait is added,
 409                                  * the C1 entry_method type should be
 410                                  * CSTATE_HALT.
 411                                  */
 412                                 cx.entry_method = ACPI_CSTATE_HALT;
 413                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 414                         }
 415                 } else {
 416                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 417                                  cx.address);
 418                 }
 419
 420                 if (cx.type == ACPI_STATE_C1) {
 421                         cx.valid = 1;
 422                 }
 423
 424                 obj = &(element->package.elements[2]);
 425                 if (obj->type != ACPI_TYPE_INTEGER)
 426                         continue;
 427
 428                 cx.latency = obj->integer.value;
 429
 430                 obj = &(element->package.elements[3]);
 431                 if (obj->type != ACPI_TYPE_INTEGER)
 432                         continue;
 433
 434                 current_count++;
 435                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 436
 437                 /*
 438                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 439                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 440                  */
 441                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 442                         pr_warn("Limiting number of power states to max (%d)\n",
 443                                 ACPI_PROCESSOR_MAX_POWER);
 444                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 445                         break;
 446                 }
 447         }
 448
 449         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 450                           current_count));
 451
 452         /* Validate number of power states discovered */
 453         if (current_count < 2)
 454                 ret = -EFAULT;
 455
 456       end:
 457         kfree(buffer.pointer);
 458
 459         return ret;
 460 }
 461
 462 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 463                                            struct acpi_processor_cx *cx)
 464 {
 465         static int bm_check_flag = -1;
 466         static int bm_control_flag = -1;
 467
 468
 469         if (!cx->address)
 470                 return;
 471
 472         /*
 473          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 474          * DMA transfers are used by any ISA device to avoid livelock.
 475          * Note that we could disable Type-F DMA (as recommended by
 476          * the erratum), but this is known to disrupt certain ISA
 477          * devices thus we take the conservative approach.
 478          */
 479         else if (errata.piix4.fdma) {
 480                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 481                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 482                 return;
 483         }
 484
 485         /* All the logic here assumes flags.bm_check is same across all CPUs */
 486         if (bm_check_flag == -1) {
 487                 /* Determine whether bm_check is needed based on CPU  */
 488                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 489                 bm_check_flag = pr->flags.bm_check;
 490                 bm_control_flag = pr->flags.bm_control;
 491         } else {
 492                 pr->flags.bm_check = bm_check_flag;
 493                 pr->flags.bm_control = bm_control_flag;
 494         }
 495
 496         if (pr->flags.bm_check) {
 497                 if (!pr->flags.bm_control) {
 498                         if (pr->flags.has_cst != 1) {
 499                                 /* bus mastering control is necessary */
 500                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 501                                         "C3 support requires BM control\n"));
 502                                 return;
 503                         } else {
 504                                 /* Here we enter C3 without bus mastering */
 505                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 506                                         "C3 support without BM control\n"));
 507                         }
 508                 }
 509         } else {
 510                 /*
 511                  * WBINVD should be set in fadt, for C3 state to be
 512                  * supported on when bm_check is not required.
 513                  */
 514                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 515                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 516                                           "Cache invalidation should work properly"
 517                                           " for C3 to be enabled on SMP systems\n"));
 518                         return;
 519                 }
 520         }
 521
 522         /*
 523          * Otherwise we've met all of our C3 requirements.
 524          * Normalize the C3 latency to expidite policy.  Enable
 525          * checking of bus mastering status (bm_check) so we can
 526          * use this in our C3 policy
 527          */
 528         cx->valid = 1;
 529
 530         /*
 531          * On older chipsets, BM_RLD needs to be set
 532          * in order for Bus Master activity to wake the
 533          * system from C3.  Newer chipsets handle DMA
 534          * during C3 automatically and BM_RLD is a NOP.
 535          * In either case, the proper way to
 536          * handle BM_RLD is to set it and leave it set.
 537          */
 538         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 539
 540         return;
 541 }
 542
 543 static int acpi_processor_power_verify(struct acpi_processor *pr)
 544 {
 545         unsigned int i;
 546         unsigned int working = 0;
 547
 548         pr->power.timer_broadcast_on_state = INT_MAX;
 549
 550         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 551                 struct acpi_processor_cx *cx = &pr->power.states[i];
 552
 553                 switch (cx->type) {
 554                 case ACPI_STATE_C1:
 555                         cx->valid = 1;
 556                         break;
 557
 558                 case ACPI_STATE_C2:
 559                         if (!cx->address)
 560                                 break;
 561                         cx->valid = 1;
 562                         break;
 563
 564                 case ACPI_STATE_C3:
 565                         acpi_processor_power_verify_c3(pr, cx);
 566                         break;
 567                 }
 568                 if (!cx->valid)
 569                         continue;
 570
 571                 lapic_timer_check_state(i, pr, cx);
 572                 tsc_check_state(cx->type);
 573                 working++;
 574         }
 575
 576         lapic_timer_propagate_broadcast(pr);
 577
 578         return (working);
 579 }
 580
 581 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 582 {
 583         unsigned int i;
 584         int result;
 585
 586
 587         /* NOTE: the idle thread may not be running while calling
 588          * this function */
 589
 590         /* Zero initialize all the C-states info. */
 591         memset(pr->power.states, 0, sizeof(pr->power.states));
 592
 593         result = acpi_processor_get_power_info_cst(pr);
 594         if (result == -ENODEV)
 595                 result = acpi_processor_get_power_info_fadt(pr);
 596
 597         if (result)
 598                 return result;
 599
 600         acpi_processor_get_power_info_default(pr);
 601
 602         pr->power.count = acpi_processor_power_verify(pr);
 603
 604         /*
 605          * if one state of type C2 or C3 is available, mark this
 606          * CPU as being "idle manageable"
 607          */
 608         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 609                 if (pr->power.states[i].valid) {
 610                         pr->power.count = i;
 611                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 612                                 pr->flags.power = 1;
 613                 }
 614         }
 615
 616         return 0;
 617 }
 618
 619 /**
 620  * acpi_idle_bm_check - checks if bus master activity was detected
 621  */
 622 static int acpi_idle_bm_check(void)
 623 {
 624         u32 bm_status = 0;
 625
 626         if (bm_check_disable)
 627                 return 0;
 628
 629         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 630         if (bm_status)
 631                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 632         /*
 633          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 634          * the true state of bus mastering activity; forcing us to
 635          * manually check the BMIDEA bit of each IDE channel.
 636          */
 637         else if (errata.piix4.bmisx) {
 638                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 639                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 640                         bm_status = 1;
 641         }
 642         return bm_status;
 643 }
 644
 645 /**
 646  * acpi_idle_do_entry - enter idle state using the appropriate method
 647  * @cx: cstate data
 648  *
 649  * Caller disables interrupt before call and enables interrupt after return.
 650  */
 651 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 652 {
 653         if (cx->entry_method == ACPI_CSTATE_FFH) {
 654                 /* Call into architectural FFH based C-state */
 655                 acpi_processor_ffh_cstate_enter(cx);
 656         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 657                 acpi_safe_halt();
 658         } else {
 659                 /* IO port based C-state */
 660                 inb(cx->address);
 661                 /* Dummy wait op - must do something useless after P_LVL2 read
 662                    because chipsets cannot guarantee that STPCLK# signal
 663                    gets asserted in time to freeze execution properly. */
 664                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 665         }
 666 }
 667
 668 /**
 669  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 670  * @dev: the target CPU
 671  * @index: the index of suggested state
 672  */
 673 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 674 {
 675         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 676
 677         ACPI_FLUSH_CPU_CACHE();
 678
 679         while (1) {
 680
 681                 if (cx->entry_method == ACPI_CSTATE_HALT)
 682                         safe_halt();
 683                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 684                         inb(cx->address);
 685                         /* See comment in acpi_idle_do_entry() */
 686                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 687                 } else
 688                         return -ENODEV;
 689         }
 690
 691         /* Never reached */
 692         return 0;
 693 }
 694
 695 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 696 {
 697         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 698                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 699 }
 700
 701 static int c3_cpu_count;
 702 static DEFINE_RAW_SPINLOCK(c3_lock);
 703
 704 /**
 705  * acpi_idle_enter_bm - enters C3 with proper BM handling
 706  * @pr: Target processor
 707  * @cx: Target state context
 708  * @timer_bc: Whether or not to change timer mode to broadcast
 709  */
 710 static void acpi_idle_enter_bm(struct acpi_processor *pr,
 711                                struct acpi_processor_cx *cx, bool timer_bc)
 712 {
 713         /*
 714          * Must be done before busmaster disable as we might need to
 715          * access HPET !
 716          */
 717         if (timer_bc)
 718                 lapic_timer_state_broadcast(pr, cx, 1);
 719
 720         /*
 721          * disable bus master
 722          * bm_check implies we need ARB_DIS
 723          * bm_control implies whether we can do ARB_DIS
 724          *
 725          * That leaves a case where bm_check is set and bm_control is
 726          * not set. In that case we cannot do much, we enter C3
 727          * without doing anything.
 728          */
 729         if (pr->flags.bm_control) {
 730                 raw_spin_lock(&c3_lock);
 731                 c3_cpu_count++;
 732                 /* Disable bus master arbitration when all CPUs are in C3 */
 733                 if (c3_cpu_count == num_online_cpus())
 734                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 735                 raw_spin_unlock(&c3_lock);
 736         }
 737
 738         acpi_idle_do_entry(cx);
 739
 740         /* Re-enable bus master arbitration */
 741         if (pr->flags.bm_control) {
 742                 raw_spin_lock(&c3_lock);
 743                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 744                 c3_cpu_count--;
 745                 raw_spin_unlock(&c3_lock);
 746         }
 747
 748         if (timer_bc)
 749                 lapic_timer_state_broadcast(pr, cx, 0);
 750 }
 751
 752 static int acpi_idle_enter(struct cpuidle_device *dev,
 753                            struct cpuidle_driver *drv, int index)
 754 {
 755         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 756         struct acpi_processor *pr;
 757
 758         pr = __this_cpu_read(processors);
 759         if (unlikely(!pr))
 760                 return -EINVAL;
 761
 762         if (cx->type != ACPI_STATE_C1) {
 763                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 764                         index = ACPI_IDLE_STATE_START;
 765                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 766                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 767                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 768                                 acpi_idle_enter_bm(pr, cx, true);
 769                                 return index;
 770                         } else if (drv->safe_state_index >= 0) {
 771                                 index = drv->safe_state_index;
 772                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 773                         } else {
 774                                 acpi_safe_halt();
 775                                 return -EBUSY;
 776                         }
 777                 }
 778         }
 779
 780         lapic_timer_state_broadcast(pr, cx, 1);
 781
 782         if (cx->type == ACPI_STATE_C3)
 783                 ACPI_FLUSH_CPU_CACHE();
 784
 785         acpi_idle_do_entry(cx);
 786
 787         lapic_timer_state_broadcast(pr, cx, 0);
 788
 789         return index;
 790 }
 791
 792 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 793                                    struct cpuidle_driver *drv, int index)
 794 {
 795         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 796
 797         if (cx->type == ACPI_STATE_C3) {
 798                 struct acpi_processor *pr = __this_cpu_read(processors);
 799
 800                 if (unlikely(!pr))
 801                         return;
 802
 803                 if (pr->flags.bm_check) {
 804                         acpi_idle_enter_bm(pr, cx, false);
 805                         return;
 806                 } else {
 807                         ACPI_FLUSH_CPU_CACHE();
 808                 }
 809         }
 810         acpi_idle_do_entry(cx);
 811 }
 812
 813 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 814                                            struct cpuidle_device *dev)
 815 {
 816         int i, count = ACPI_IDLE_STATE_START;
 817         struct acpi_processor_cx *cx;
 818
 819         if (max_cstate == 0)
 820                 max_cstate = 1;
 821
 822         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 823                 cx = &pr->power.states[i];
 824
 825                 if (!cx->valid)
 826                         continue;
 827
 828                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 829
 830                 count++;
 831                 if (count == CPUIDLE_STATE_MAX)
 832                         break;
 833         }
 834
 835         if (!count)
 836                 return -EINVAL;
 837
 838         return 0;
 839 }
 840
 841 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 842 {
 843         int i, count;
 844         struct acpi_processor_cx *cx;
 845         struct cpuidle_state *state;
 846         struct cpuidle_driver *drv = &acpi_idle_driver;
 847
 848         if (max_cstate == 0)
 849                 max_cstate = 1;
 850
 851         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 852                 cpuidle_poll_state_init(drv);
 853                 count = 1;
 854         } else {
 855                 count = 0;
 856         }
 857
 858         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 859                 cx = &pr->power.states[i];
 860
 861                 if (!cx->valid)
 862                         continue;
 863
 864                 state = &drv->states[count];
 865                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 866                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 867                 state->exit_latency = cx->latency;
 868                 state->target_residency = cx->latency * latency_factor;
 869                 state->enter = acpi_idle_enter;
 870
 871                 state->flags = 0;
 872                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 873                         state->enter_dead = acpi_idle_play_dead;
 874                         drv->safe_state_index = count;
 875                 }
 876                 /*
 877                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 878                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 879                  * particularly interesting from the suspend-to-idle angle, so
 880                  * avoid C1 and the situations in which we may need to fall back
 881                  * to it altogether.
 882                  */
 883                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 884                         state->enter_s2idle = acpi_idle_enter_s2idle;
 885
 886                 count++;
 887                 if (count == CPUIDLE_STATE_MAX)
 888                         break;
 889         }
 890
 891         drv->state_count = count;
 892
 893         if (!count)
 894                 return -EINVAL;
 895
 896         return 0;
 897 }
 898
 899 static inline void acpi_processor_cstate_first_run_checks(void)
 900 {
 901         acpi_status status;
 902         static int first_run;
 903
 904         if (first_run)
 905                 return;
 906         dmi_check_system(processor_power_dmi_table);
 907         max_cstate = acpi_processor_cstate_check(max_cstate);
 908         if (max_cstate < ACPI_C_STATES_MAX)
 909                 pr_notice("ACPI: processor limited to max C-state %d\n",
 910                           max_cstate);
 911         first_run++;
 912
 913         if (acpi_gbl_FADT.cst_control && !nocst) {
 914                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 915                                             acpi_gbl_FADT.cst_control, 8);
 916                 if (ACPI_FAILURE(status))
 917                         ACPI_EXCEPTION((AE_INFO, status,
 918                                         "Notifying BIOS of _CST ability failed"));
 919         }
 920 }
 921 #else
 922
 923 static inline int disabled_by_idle_boot_param(void) { return 0; }
 924 static inline void acpi_processor_cstate_first_run_checks(void) { }
 925 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 926 {
 927         return -ENODEV;
 928 }
 929
 930 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 931                                            struct cpuidle_device *dev)
 932 {
 933         return -EINVAL;
 934 }
 935
 936 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 937 {
 938         return -EINVAL;
 939 }
 940
 941 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 942
 943 struct acpi_lpi_states_array {
 944         unsigned int size;
 945         unsigned int composite_states_size;
 946         struct acpi_lpi_state *entries;
 947         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 948 };
 949
 950 static int obj_get_integer(union acpi_object *obj, u32 *value)
 951 {
 952         if (obj->type != ACPI_TYPE_INTEGER)
 953                 return -EINVAL;
 954
 955         *value = obj->integer.value;
 956         return 0;
 957 }
 958
 959 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 960                                        struct acpi_lpi_states_array *info)
 961 {
 962         acpi_status status;
 963         int ret = 0;
 964         int pkg_count, state_idx = 1, loop;
 965         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 966         union acpi_object *lpi_data;
 967         struct acpi_lpi_state *lpi_state;
 968
 969         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 970         if (ACPI_FAILURE(status)) {
 971                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 972                 return -ENODEV;
 973         }
 974
 975         lpi_data = buffer.pointer;
 976
 977         /* There must be at least 4 elements = 3 elements + 1 package */
 978         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 979             lpi_data->package.count < 4) {
 980                 pr_debug("not enough elements in _LPI\n");
 981                 ret = -ENODATA;
 982                 goto end;
 983         }
 984
 985         pkg_count = lpi_data->package.elements[2].integer.value;
 986
 987         /* Validate number of power states. */
 988         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 989                 pr_debug("count given by _LPI is not valid\n");
 990                 ret = -ENODATA;
 991                 goto end;
 992         }
 993
 994         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 995         if (!lpi_state) {
 996                 ret = -ENOMEM;
 997                 goto end;
 998         }
 999
1000         info->size = pkg_count;
1001         info->entries = lpi_state;
1002
1003         /* LPI States start at index 3 */
1004         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1005                 union acpi_object *element, *pkg_elem, *obj;
1006
1007                 element = &lpi_data->package.elements[loop];
1008                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1009                         continue;
1010
1011                 pkg_elem = element->package.elements;
1012
1013                 obj = pkg_elem + 6;
1014                 if (obj->type == ACPI_TYPE_BUFFER) {
1015                         struct acpi_power_register *reg;
1016
1017                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1018                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1019                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1020                                 continue;
1021
1022                         lpi_state->address = reg->address;
1023                         lpi_state->entry_method =
1024                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1025                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1026                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1027                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1028                         lpi_state->address = obj->integer.value;
1029                 } else {
1030                         continue;
1031                 }
1032
1033                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1034
1035                 obj = pkg_elem + 9;
1036                 if (obj->type == ACPI_TYPE_STRING)
1037                         strlcpy(lpi_state->desc, obj->string.pointer,
1038                                 ACPI_CX_DESC_LEN);
1039
1040                 lpi_state->index = state_idx;
1041                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1042                         pr_debug("No min. residency found, assuming 10 us\n");
1043                         lpi_state->min_residency = 10;
1044                 }
1045
1046                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1047                         pr_debug("No wakeup residency found, assuming 10 us\n");
1048                         lpi_state->wake_latency = 10;
1049                 }
1050
1051                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1052                         lpi_state->flags = 0;
1053
1054                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1055                         lpi_state->arch_flags = 0;
1056
1057                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1058                         lpi_state->res_cnt_freq = 1;
1059
1060                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1061                         lpi_state->enable_parent_state = 0;
1062         }
1063
1064         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1065 end:
1066         kfree(buffer.pointer);
1067         return ret;
1068 }
1069
1070 /*
1071  * flat_state_cnt - the number of composite LPI states after the process of flattening
1072  */
1073 static int flat_state_cnt;
1074
1075 /**
1076  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1077  *
1078  * @local: local LPI state
1079  * @parent: parent LPI state
1080  * @result: composite LPI state
1081  */
1082 static bool combine_lpi_states(struct acpi_lpi_state *local,
1083                                struct acpi_lpi_state *parent,
1084                                struct acpi_lpi_state *result)
1085 {
1086         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1087                 if (!parent->address) /* 0 means autopromotable */
1088                         return false;
1089                 result->address = local->address + parent->address;
1090         } else {
1091                 result->address = parent->address;
1092         }
1093
1094         result->min_residency = max(local->min_residency, parent->min_residency);
1095         result->wake_latency = local->wake_latency + parent->wake_latency;
1096         result->enable_parent_state = parent->enable_parent_state;
1097         result->entry_method = local->entry_method;
1098
1099         result->flags = parent->flags;
1100         result->arch_flags = parent->arch_flags;
1101         result->index = parent->index;
1102
1103         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1104         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1105         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1106         return true;
1107 }
1108
1109 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1110
1111 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1112                                   struct acpi_lpi_state *t)
1113 {
1114         curr_level->composite_states[curr_level->composite_states_size++] = t;
1115 }
1116
1117 static int flatten_lpi_states(struct acpi_processor *pr,
1118                               struct acpi_lpi_states_array *curr_level,
1119                               struct acpi_lpi_states_array *prev_level)
1120 {
1121         int i, j, state_count = curr_level->size;
1122         struct acpi_lpi_state *p, *t = curr_level->entries;
1123
1124         curr_level->composite_states_size = 0;
1125         for (j = 0; j < state_count; j++, t++) {
1126                 struct acpi_lpi_state *flpi;
1127
1128                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1129                         continue;
1130
1131                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1132                         pr_warn("Limiting number of LPI states to max (%d)\n",
1133                                 ACPI_PROCESSOR_MAX_POWER);
1134                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1135                         break;
1136                 }
1137
1138                 flpi = &pr->power.lpi_states[flat_state_cnt];
1139
1140                 if (!prev_level) { /* leaf/processor node */
1141                         memcpy(flpi, t, sizeof(*t));
1142                         stash_composite_state(curr_level, flpi);
1143                         flat_state_cnt++;
1144                         continue;
1145                 }
1146
1147                 for (i = 0; i < prev_level->composite_states_size; i++) {
1148                         p = prev_level->composite_states[i];
1149                         if (t->index <= p->enable_parent_state &&
1150                             combine_lpi_states(p, t, flpi)) {
1151                                 stash_composite_state(curr_level, flpi);
1152                                 flat_state_cnt++;
1153                                 flpi++;
1154                         }
1155                 }
1156         }
1157
1158         kfree(curr_level->entries);
1159         return 0;
1160 }
1161
1162 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1163 {
1164         int ret, i;
1165         acpi_status status;
1166         acpi_handle handle = pr->handle, pr_ahandle;
1167         struct acpi_device *d = NULL;
1168         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1169
1170         if (!osc_pc_lpi_support_confirmed)
1171                 return -EOPNOTSUPP;
1172
1173         if (!acpi_has_method(handle, "_LPI"))
1174                 return -EINVAL;
1175
1176         flat_state_cnt = 0;
1177         prev = &info[0];
1178         curr = &info[1];
1179         handle = pr->handle;
1180         ret = acpi_processor_evaluate_lpi(handle, prev);
1181         if (ret)
1182                 return ret;
1183         flatten_lpi_states(pr, prev, NULL);
1184
1185         status = acpi_get_parent(handle, &pr_ahandle);
1186         while (ACPI_SUCCESS(status)) {
1187                 acpi_bus_get_device(pr_ahandle, &d);
1188                 handle = pr_ahandle;
1189
1190                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1191                         break;
1192
1193                 /* can be optional ? */
1194                 if (!acpi_has_method(handle, "_LPI"))
1195                         break;
1196
1197                 ret = acpi_processor_evaluate_lpi(handle, curr);
1198                 if (ret)
1199                         break;
1200
1201                 /* flatten all the LPI states in this level of hierarchy */
1202                 flatten_lpi_states(pr, curr, prev);
1203
1204                 tmp = prev, prev = curr, curr = tmp;
1205
1206                 status = acpi_get_parent(handle, &pr_ahandle);
1207         }
1208
1209         pr->power.count = flat_state_cnt;
1210         /* reset the index after flattening */
1211         for (i = 0; i < pr->power.count; i++)
1212                 pr->power.lpi_states[i].index = i;
1213
1214         /* Tell driver that _LPI is supported. */
1215         pr->flags.has_lpi = 1;
1216         pr->flags.power = 1;
1217
1218         return 0;
1219 }
1220
1221 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1222 {
1223         return -ENODEV;
1224 }
1225
1226 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1227 {
1228         return -ENODEV;
1229 }
1230
1231 /**
1232  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1233  * @dev: the target CPU
1234  * @drv: cpuidle driver containing cpuidle state info
1235  * @index: index of target state
1236  *
1237  * Return: 0 for success or negative value for error
1238  */
1239 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1240                                struct cpuidle_driver *drv, int index)
1241 {
1242         struct acpi_processor *pr;
1243         struct acpi_lpi_state *lpi;
1244
1245         pr = __this_cpu_read(processors);
1246
1247         if (unlikely(!pr))
1248                 return -EINVAL;
1249
1250         lpi = &pr->power.lpi_states[index];
1251         if (lpi->entry_method == ACPI_CSTATE_FFH)
1252                 return acpi_processor_ffh_lpi_enter(lpi);
1253
1254         return -EINVAL;
1255 }
1256
1257 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1258 {
1259         int i;
1260         struct acpi_lpi_state *lpi;
1261         struct cpuidle_state *state;
1262         struct cpuidle_driver *drv = &acpi_idle_driver;
1263
1264         if (!pr->flags.has_lpi)
1265                 return -EOPNOTSUPP;
1266
1267         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1268                 lpi = &pr->power.lpi_states[i];
1269
1270                 state = &drv->states[i];
1271                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1272                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1273                 state->exit_latency = lpi->wake_latency;
1274                 state->target_residency = lpi->min_residency;
1275                 if (lpi->arch_flags)
1276                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1277                 state->enter = acpi_idle_lpi_enter;
1278                 drv->safe_state_index = i;
1279         }
1280
1281         drv->state_count = i;
1282
1283         return 0;
1284 }
1285
1286 /**
1287  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1288  * global state data i.e. idle routines
1289  *
1290  * @pr: the ACPI processor
1291  */
1292 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1293 {
1294         int i;
1295         struct cpuidle_driver *drv = &acpi_idle_driver;
1296
1297         if (!pr->flags.power_setup_done || !pr->flags.power)
1298                 return -EINVAL;
1299
1300         drv->safe_state_index = -1;
1301         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1302                 drv->states[i].name[0] = '\0';
1303                 drv->states[i].desc[0] = '\0';
1304         }
1305
1306         if (pr->flags.has_lpi)
1307                 return acpi_processor_setup_lpi_states(pr);
1308
1309         return acpi_processor_setup_cstates(pr);
1310 }
1311
1312 /**
1313  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1314  * device i.e. per-cpu data
1315  *
1316  * @pr: the ACPI processor
1317  * @dev : the cpuidle device
1318  */
1319 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1320                                             struct cpuidle_device *dev)
1321 {
1322         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1323                 return -EINVAL;
1324
1325         dev->cpu = pr->id;
1326         if (pr->flags.has_lpi)
1327                 return acpi_processor_ffh_lpi_probe(pr->id);
1328
1329         return acpi_processor_setup_cpuidle_cx(pr, dev);
1330 }
1331
1332 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1333 {
1334         int ret;
1335
1336         ret = acpi_processor_get_lpi_info(pr);
1337         if (ret)
1338                 ret = acpi_processor_get_cstate_info(pr);
1339
1340         return ret;
1341 }
1342
1343 int acpi_processor_hotplug(struct acpi_processor *pr)
1344 {
1345         int ret = 0;
1346         struct cpuidle_device *dev;
1347
1348         if (disabled_by_idle_boot_param())
1349                 return 0;
1350
1351         if (!pr->flags.power_setup_done)
1352                 return -ENODEV;
1353
1354         dev = per_cpu(acpi_cpuidle_device, pr->id);
1355         cpuidle_pause_and_lock();
1356         cpuidle_disable_device(dev);
1357         ret = acpi_processor_get_power_info(pr);
1358         if (!ret && pr->flags.power) {
1359                 acpi_processor_setup_cpuidle_dev(pr, dev);
1360                 ret = cpuidle_enable_device(dev);
1361         }
1362         cpuidle_resume_and_unlock();
1363
1364         return ret;
1365 }
1366
1367 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1368 {
1369         int cpu;
1370         struct acpi_processor *_pr;
1371         struct cpuidle_device *dev;
1372
1373         if (disabled_by_idle_boot_param())
1374                 return 0;
1375
1376         if (!pr->flags.power_setup_done)
1377                 return -ENODEV;
1378
1379         /*
1380          * FIXME:  Design the ACPI notification to make it once per
1381          * system instead of once per-cpu.  This condition is a hack
1382          * to make the code that updates C-States be called once.
1383          */
1384
1385         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1386
1387                 /* Protect against cpu-hotplug */
1388                 get_online_cpus();
1389                 cpuidle_pause_and_lock();
1390
1391                 /* Disable all cpuidle devices */
1392                 for_each_online_cpu(cpu) {
1393                         _pr = per_cpu(processors, cpu);
1394                         if (!_pr || !_pr->flags.power_setup_done)
1395                                 continue;
1396                         dev = per_cpu(acpi_cpuidle_device, cpu);
1397                         cpuidle_disable_device(dev);
1398                 }
1399
1400                 /* Populate Updated C-state information */
1401                 acpi_processor_get_power_info(pr);
1402                 acpi_processor_setup_cpuidle_states(pr);
1403
1404                 /* Enable all cpuidle devices */
1405                 for_each_online_cpu(cpu) {
1406                         _pr = per_cpu(processors, cpu);
1407                         if (!_pr || !_pr->flags.power_setup_done)
1408                                 continue;
1409                         acpi_processor_get_power_info(_pr);
1410                         if (_pr->flags.power) {
1411                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1412                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1413                                 cpuidle_enable_device(dev);
1414                         }
1415                 }
1416                 cpuidle_resume_and_unlock();
1417                 put_online_cpus();
1418         }
1419
1420         return 0;
1421 }
1422
1423 static int acpi_processor_registered;
1424
1425 int acpi_processor_power_init(struct acpi_processor *pr)
1426 {
1427         int retval;
1428         struct cpuidle_device *dev;
1429
1430         if (disabled_by_idle_boot_param())
1431                 return 0;
1432
1433         acpi_processor_cstate_first_run_checks();
1434
1435         if (!acpi_processor_get_power_info(pr))
1436                 pr->flags.power_setup_done = 1;
1437
1438         /*
1439          * Install the idle handler if processor power management is supported.
1440          * Note that we use previously set idle handler will be used on
1441          * platforms that only support C1.
1442          */
1443         if (pr->flags.power) {
1444                 /* Register acpi_idle_driver if not already registered */
1445                 if (!acpi_processor_registered) {
1446                         acpi_processor_setup_cpuidle_states(pr);
1447                         retval = cpuidle_register_driver(&acpi_idle_driver);
1448                         if (retval)
1449                                 return retval;
1450                         pr_debug("%s registered with cpuidle\n",
1451                                  acpi_idle_driver.name);
1452                 }
1453
1454                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1455                 if (!dev)
1456                         return -ENOMEM;
1457                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1458
1459                 acpi_processor_setup_cpuidle_dev(pr, dev);
1460
1461                 /* Register per-cpu cpuidle_device. Cpuidle driver
1462                  * must already be registered before registering device
1463                  */
1464                 retval = cpuidle_register_device(dev);
1465                 if (retval) {
1466                         if (acpi_processor_registered == 0)
1467                                 cpuidle_unregister_driver(&acpi_idle_driver);
1468                         return retval;
1469                 }
1470                 acpi_processor_registered++;
1471         }
1472         return 0;
1473 }
1474
1475 int acpi_processor_power_exit(struct acpi_processor *pr)
1476 {
1477         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1478
1479         if (disabled_by_idle_boot_param())
1480                 return 0;
1481
1482         if (pr->flags.power) {
1483                 cpuidle_unregister_device(dev);
1484                 acpi_processor_registered--;
1485                 if (acpi_processor_registered == 0)
1486                         cpuidle_unregister_driver(&acpi_idle_driver);
1487         }
1488
1489         pr->flags.power_setup_done = 0;
1490         return 0;
1491 }