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         case X86_VENDOR_CENTAUR:
 211                 /*
 212                  * AMD Fam10h TSC will tick in all
 213                  * C/P/S0/S1 states when this bit is set.
 214                  */
 215                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 216                         return;
 217
 218                 /*FALL THROUGH*/
 219         default:
 220                 /* TSC could halt in idle, so notify users */
 221                 if (state > ACPI_STATE_C1)
 222                         mark_tsc_unstable("TSC halts in idle");
 223         }
 224 }
 225 #else
 226 static void tsc_check_state(int state) { return; }
 227 #endif
 228
 229 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 230 {
 231
 232         if (!pr->pblk)
 233                 return -ENODEV;
 234
 235         /* if info is obtained from pblk/fadt, type equals state */
 236         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 237         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 238
 239 #ifndef CONFIG_HOTPLUG_CPU
 240         /*
 241          * Check for P_LVL2_UP flag before entering C2 and above on
 242          * an SMP system.
 243          */
 244         if ((num_online_cpus() > 1) &&
 245             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 246                 return -ENODEV;
 247 #endif
 248
 249         /* determine C2 and C3 address from pblk */
 250         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 251         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 252
 253         /* determine latencies from FADT */
 254         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 255         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 256
 257         /*
 258          * FADT specified C2 latency must be less than or equal to
 259          * 100 microseconds.
 260          */
 261         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 262                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 263                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 264                 /* invalidate C2 */
 265                 pr->power.states[ACPI_STATE_C2].address = 0;
 266         }
 267
 268         /*
 269          * FADT supplied C3 latency must be less than or equal to
 270          * 1000 microseconds.
 271          */
 272         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 273                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 274                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 275                 /* invalidate C3 */
 276                 pr->power.states[ACPI_STATE_C3].address = 0;
 277         }
 278
 279         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 280                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 281                           pr->power.states[ACPI_STATE_C2].address,
 282                           pr->power.states[ACPI_STATE_C3].address));
 283
 284         return 0;
 285 }
 286
 287 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 288 {
 289         if (!pr->power.states[ACPI_STATE_C1].valid) {
 290                 /* set the first C-State to C1 */
 291                 /* all processors need to support C1 */
 292                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 293                 pr->power.states[ACPI_STATE_C1].valid = 1;
 294                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 295
 296                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
 297                          ACPI_CX_DESC_LEN, "ACPI HLT");
 298         }
 299         /* the C0 state only exists as a filler in our array */
 300         pr->power.states[ACPI_STATE_C0].valid = 1;
 301         return 0;
 302 }
 303
 304 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 305 {
 306         acpi_status status;
 307         u64 count;
 308         int current_count;
 309         int i, ret = 0;
 310         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 311         union acpi_object *cst;
 312
 313         if (nocst)
 314                 return -ENODEV;
 315
 316         current_count = 0;
 317
 318         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 319         if (ACPI_FAILURE(status)) {
 320                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 321                 return -ENODEV;
 322         }
 323
 324         cst = buffer.pointer;
 325
 326         /* There must be at least 2 elements */
 327         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 328                 pr_err("not enough elements in _CST\n");
 329                 ret = -EFAULT;
 330                 goto end;
 331         }
 332
 333         count = cst->package.elements[0].integer.value;
 334
 335         /* Validate number of power states. */
 336         if (count < 1 || count != cst->package.count - 1) {
 337                 pr_err("count given by _CST is not valid\n");
 338                 ret = -EFAULT;
 339                 goto end;
 340         }
 341
 342         /* Tell driver that at least _CST is supported. */
 343         pr->flags.has_cst = 1;
 344
 345         for (i = 1; i <= count; i++) {
 346                 union acpi_object *element;
 347                 union acpi_object *obj;
 348                 struct acpi_power_register *reg;
 349                 struct acpi_processor_cx cx;
 350
 351                 memset(&cx, 0, sizeof(cx));
 352
 353                 element = &(cst->package.elements[i]);
 354                 if (element->type != ACPI_TYPE_PACKAGE)
 355                         continue;
 356
 357                 if (element->package.count != 4)
 358                         continue;
 359
 360                 obj = &(element->package.elements[0]);
 361
 362                 if (obj->type != ACPI_TYPE_BUFFER)
 363                         continue;
 364
 365                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 366
 367                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 368                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 369                         continue;
 370
 371                 /* There should be an easy way to extract an integer... */
 372                 obj = &(element->package.elements[1]);
 373                 if (obj->type != ACPI_TYPE_INTEGER)
 374                         continue;
 375
 376                 cx.type = obj->integer.value;
 377                 /*
 378                  * Some buggy BIOSes won't list C1 in _CST -
 379                  * Let acpi_processor_get_power_info_default() handle them later
 380                  */
 381                 if (i == 1 && cx.type != ACPI_STATE_C1)
 382                         current_count++;
 383
 384                 cx.address = reg->address;
 385                 cx.index = current_count + 1;
 386
 387                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 388                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 389                         if (acpi_processor_ffh_cstate_probe
 390                                         (pr->id, &cx, reg) == 0) {
 391                                 cx.entry_method = ACPI_CSTATE_FFH;
 392                         } else if (cx.type == ACPI_STATE_C1) {
 393                                 /*
 394                                  * C1 is a special case where FIXED_HARDWARE
 395                                  * can be handled in non-MWAIT way as well.
 396                                  * In that case, save this _CST entry info.
 397                                  * Otherwise, ignore this info and continue.
 398                                  */
 399                                 cx.entry_method = ACPI_CSTATE_HALT;
 400                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 401                         } else {
 402                                 continue;
 403                         }
 404                         if (cx.type == ACPI_STATE_C1 &&
 405                             (boot_option_idle_override == IDLE_NOMWAIT)) {
 406                                 /*
 407                                  * In most cases the C1 space_id obtained from
 408                                  * _CST object is FIXED_HARDWARE access mode.
 409                                  * But when the option of idle=halt is added,
 410                                  * the entry_method type should be changed from
 411                                  * CSTATE_FFH to CSTATE_HALT.
 412                                  * When the option of idle=nomwait is added,
 413                                  * the C1 entry_method type should be
 414                                  * CSTATE_HALT.
 415                                  */
 416                                 cx.entry_method = ACPI_CSTATE_HALT;
 417                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 418                         }
 419                 } else {
 420                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 421                                  cx.address);
 422                 }
 423
 424                 if (cx.type == ACPI_STATE_C1) {
 425                         cx.valid = 1;
 426                 }
 427
 428                 obj = &(element->package.elements[2]);
 429                 if (obj->type != ACPI_TYPE_INTEGER)
 430                         continue;
 431
 432                 cx.latency = obj->integer.value;
 433
 434                 obj = &(element->package.elements[3]);
 435                 if (obj->type != ACPI_TYPE_INTEGER)
 436                         continue;
 437
 438                 current_count++;
 439                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 440
 441                 /*
 442                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 443                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 444                  */
 445                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 446                         pr_warn("Limiting number of power states to max (%d)\n",
 447                                 ACPI_PROCESSOR_MAX_POWER);
 448                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 449                         break;
 450                 }
 451         }
 452
 453         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 454                           current_count));
 455
 456         /* Validate number of power states discovered */
 457         if (current_count < 2)
 458                 ret = -EFAULT;
 459
 460       end:
 461         kfree(buffer.pointer);
 462
 463         return ret;
 464 }
 465
 466 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 467                                            struct acpi_processor_cx *cx)
 468 {
 469         static int bm_check_flag = -1;
 470         static int bm_control_flag = -1;
 471
 472
 473         if (!cx->address)
 474                 return;
 475
 476         /*
 477          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 478          * DMA transfers are used by any ISA device to avoid livelock.
 479          * Note that we could disable Type-F DMA (as recommended by
 480          * the erratum), but this is known to disrupt certain ISA
 481          * devices thus we take the conservative approach.
 482          */
 483         else if (errata.piix4.fdma) {
 484                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 485                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 486                 return;
 487         }
 488
 489         /* All the logic here assumes flags.bm_check is same across all CPUs */
 490         if (bm_check_flag == -1) {
 491                 /* Determine whether bm_check is needed based on CPU  */
 492                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 493                 bm_check_flag = pr->flags.bm_check;
 494                 bm_control_flag = pr->flags.bm_control;
 495         } else {
 496                 pr->flags.bm_check = bm_check_flag;
 497                 pr->flags.bm_control = bm_control_flag;
 498         }
 499
 500         if (pr->flags.bm_check) {
 501                 if (!pr->flags.bm_control) {
 502                         if (pr->flags.has_cst != 1) {
 503                                 /* bus mastering control is necessary */
 504                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 505                                         "C3 support requires BM control\n"));
 506                                 return;
 507                         } else {
 508                                 /* Here we enter C3 without bus mastering */
 509                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 510                                         "C3 support without BM control\n"));
 511                         }
 512                 }
 513         } else {
 514                 /*
 515                  * WBINVD should be set in fadt, for C3 state to be
 516                  * supported on when bm_check is not required.
 517                  */
 518                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 519                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 520                                           "Cache invalidation should work properly"
 521                                           " for C3 to be enabled on SMP systems\n"));
 522                         return;
 523                 }
 524         }
 525
 526         /*
 527          * Otherwise we've met all of our C3 requirements.
 528          * Normalize the C3 latency to expidite policy.  Enable
 529          * checking of bus mastering status (bm_check) so we can
 530          * use this in our C3 policy
 531          */
 532         cx->valid = 1;
 533
 534         /*
 535          * On older chipsets, BM_RLD needs to be set
 536          * in order for Bus Master activity to wake the
 537          * system from C3.  Newer chipsets handle DMA
 538          * during C3 automatically and BM_RLD is a NOP.
 539          * In either case, the proper way to
 540          * handle BM_RLD is to set it and leave it set.
 541          */
 542         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 543
 544         return;
 545 }
 546
 547 static int acpi_processor_power_verify(struct acpi_processor *pr)
 548 {
 549         unsigned int i;
 550         unsigned int working = 0;
 551
 552         pr->power.timer_broadcast_on_state = INT_MAX;
 553
 554         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 555                 struct acpi_processor_cx *cx = &pr->power.states[i];
 556
 557                 switch (cx->type) {
 558                 case ACPI_STATE_C1:
 559                         cx->valid = 1;
 560                         break;
 561
 562                 case ACPI_STATE_C2:
 563                         if (!cx->address)
 564                                 break;
 565                         cx->valid = 1;
 566                         break;
 567
 568                 case ACPI_STATE_C3:
 569                         acpi_processor_power_verify_c3(pr, cx);
 570                         break;
 571                 }
 572                 if (!cx->valid)
 573                         continue;
 574
 575                 lapic_timer_check_state(i, pr, cx);
 576                 tsc_check_state(cx->type);
 577                 working++;
 578         }
 579
 580         lapic_timer_propagate_broadcast(pr);
 581
 582         return (working);
 583 }
 584
 585 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 586 {
 587         unsigned int i;
 588         int result;
 589
 590
 591         /* NOTE: the idle thread may not be running while calling
 592          * this function */
 593
 594         /* Zero initialize all the C-states info. */
 595         memset(pr->power.states, 0, sizeof(pr->power.states));
 596
 597         result = acpi_processor_get_power_info_cst(pr);
 598         if (result == -ENODEV)
 599                 result = acpi_processor_get_power_info_fadt(pr);
 600
 601         if (result)
 602                 return result;
 603
 604         acpi_processor_get_power_info_default(pr);
 605
 606         pr->power.count = acpi_processor_power_verify(pr);
 607
 608         /*
 609          * if one state of type C2 or C3 is available, mark this
 610          * CPU as being "idle manageable"
 611          */
 612         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 613                 if (pr->power.states[i].valid) {
 614                         pr->power.count = i;
 615                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 616                                 pr->flags.power = 1;
 617                 }
 618         }
 619
 620         return 0;
 621 }
 622
 623 /**
 624  * acpi_idle_bm_check - checks if bus master activity was detected
 625  */
 626 static int acpi_idle_bm_check(void)
 627 {
 628         u32 bm_status = 0;
 629
 630         if (bm_check_disable)
 631                 return 0;
 632
 633         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 634         if (bm_status)
 635                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 636         /*
 637          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 638          * the true state of bus mastering activity; forcing us to
 639          * manually check the BMIDEA bit of each IDE channel.
 640          */
 641         else if (errata.piix4.bmisx) {
 642                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 643                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 644                         bm_status = 1;
 645         }
 646         return bm_status;
 647 }
 648
 649 /**
 650  * acpi_idle_do_entry - enter idle state using the appropriate method
 651  * @cx: cstate data
 652  *
 653  * Caller disables interrupt before call and enables interrupt after return.
 654  */
 655 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 656 {
 657         if (cx->entry_method == ACPI_CSTATE_FFH) {
 658                 /* Call into architectural FFH based C-state */
 659                 acpi_processor_ffh_cstate_enter(cx);
 660         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 661                 acpi_safe_halt();
 662         } else {
 663                 /* IO port based C-state */
 664                 inb(cx->address);
 665                 /* Dummy wait op - must do something useless after P_LVL2 read
 666                    because chipsets cannot guarantee that STPCLK# signal
 667                    gets asserted in time to freeze execution properly. */
 668                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 669         }
 670 }
 671
 672 /**
 673  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 674  * @dev: the target CPU
 675  * @index: the index of suggested state
 676  */
 677 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 678 {
 679         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 680
 681         ACPI_FLUSH_CPU_CACHE();
 682
 683         while (1) {
 684
 685                 if (cx->entry_method == ACPI_CSTATE_HALT)
 686                         safe_halt();
 687                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 688                         inb(cx->address);
 689                         /* See comment in acpi_idle_do_entry() */
 690                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 691                 } else
 692                         return -ENODEV;
 693         }
 694
 695         /* Never reached */
 696         return 0;
 697 }
 698
 699 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 700 {
 701         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 702                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 703 }
 704
 705 static int c3_cpu_count;
 706 static DEFINE_RAW_SPINLOCK(c3_lock);
 707
 708 /**
 709  * acpi_idle_enter_bm - enters C3 with proper BM handling
 710  * @pr: Target processor
 711  * @cx: Target state context
 712  * @timer_bc: Whether or not to change timer mode to broadcast
 713  */
 714 static void acpi_idle_enter_bm(struct acpi_processor *pr,
 715                                struct acpi_processor_cx *cx, bool timer_bc)
 716 {
 717         acpi_unlazy_tlb(smp_processor_id());
 718
 719         /*
 720          * Must be done before busmaster disable as we might need to
 721          * access HPET !
 722          */
 723         if (timer_bc)
 724                 lapic_timer_state_broadcast(pr, cx, 1);
 725
 726         /*
 727          * disable bus master
 728          * bm_check implies we need ARB_DIS
 729          * bm_control implies whether we can do ARB_DIS
 730          *
 731          * That leaves a case where bm_check is set and bm_control is
 732          * not set. In that case we cannot do much, we enter C3
 733          * without doing anything.
 734          */
 735         if (pr->flags.bm_control) {
 736                 raw_spin_lock(&c3_lock);
 737                 c3_cpu_count++;
 738                 /* Disable bus master arbitration when all CPUs are in C3 */
 739                 if (c3_cpu_count == num_online_cpus())
 740                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 741                 raw_spin_unlock(&c3_lock);
 742         }
 743
 744         acpi_idle_do_entry(cx);
 745
 746         /* Re-enable bus master arbitration */
 747         if (pr->flags.bm_control) {
 748                 raw_spin_lock(&c3_lock);
 749                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 750                 c3_cpu_count--;
 751                 raw_spin_unlock(&c3_lock);
 752         }
 753
 754         if (timer_bc)
 755                 lapic_timer_state_broadcast(pr, cx, 0);
 756 }
 757
 758 static int acpi_idle_enter(struct cpuidle_device *dev,
 759                            struct cpuidle_driver *drv, int index)
 760 {
 761         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 762         struct acpi_processor *pr;
 763
 764         pr = __this_cpu_read(processors);
 765         if (unlikely(!pr))
 766                 return -EINVAL;
 767
 768         if (cx->type != ACPI_STATE_C1) {
 769                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 770                         index = ACPI_IDLE_STATE_START;
 771                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 772                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 773                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 774                                 acpi_idle_enter_bm(pr, cx, true);
 775                                 return index;
 776                         } else if (drv->safe_state_index >= 0) {
 777                                 index = drv->safe_state_index;
 778                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 779                         } else {
 780                                 acpi_safe_halt();
 781                                 return -EBUSY;
 782                         }
 783                 }
 784         }
 785
 786         lapic_timer_state_broadcast(pr, cx, 1);
 787
 788         if (cx->type == ACPI_STATE_C3)
 789                 ACPI_FLUSH_CPU_CACHE();
 790
 791         acpi_idle_do_entry(cx);
 792
 793         lapic_timer_state_broadcast(pr, cx, 0);
 794
 795         return index;
 796 }
 797
 798 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 799                                    struct cpuidle_driver *drv, int index)
 800 {
 801         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 802
 803         if (cx->type == ACPI_STATE_C3) {
 804                 struct acpi_processor *pr = __this_cpu_read(processors);
 805
 806                 if (unlikely(!pr))
 807                         return;
 808
 809                 if (pr->flags.bm_check) {
 810                         acpi_idle_enter_bm(pr, cx, false);
 811                         return;
 812                 } else {
 813                         ACPI_FLUSH_CPU_CACHE();
 814                 }
 815         }
 816         acpi_idle_do_entry(cx);
 817 }
 818
 819 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 820                                            struct cpuidle_device *dev)
 821 {
 822         int i, count = ACPI_IDLE_STATE_START;
 823         struct acpi_processor_cx *cx;
 824
 825         if (max_cstate == 0)
 826                 max_cstate = 1;
 827
 828         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 829                 cx = &pr->power.states[i];
 830
 831                 if (!cx->valid)
 832                         continue;
 833
 834                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 835
 836                 count++;
 837                 if (count == CPUIDLE_STATE_MAX)
 838                         break;
 839         }
 840
 841         if (!count)
 842                 return -EINVAL;
 843
 844         return 0;
 845 }
 846
 847 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 848 {
 849         int i, count;
 850         struct acpi_processor_cx *cx;
 851         struct cpuidle_state *state;
 852         struct cpuidle_driver *drv = &acpi_idle_driver;
 853
 854         if (max_cstate == 0)
 855                 max_cstate = 1;
 856
 857         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 858                 cpuidle_poll_state_init(drv);
 859                 count = 1;
 860         } else {
 861                 count = 0;
 862         }
 863
 864         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 865                 cx = &pr->power.states[i];
 866
 867                 if (!cx->valid)
 868                         continue;
 869
 870                 state = &drv->states[count];
 871                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 872                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 873                 state->exit_latency = cx->latency;
 874                 state->target_residency = cx->latency * latency_factor;
 875                 state->enter = acpi_idle_enter;
 876
 877                 state->flags = 0;
 878                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 879                         state->enter_dead = acpi_idle_play_dead;
 880                         drv->safe_state_index = count;
 881                 }
 882                 /*
 883                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 884                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 885                  * particularly interesting from the suspend-to-idle angle, so
 886                  * avoid C1 and the situations in which we may need to fall back
 887                  * to it altogether.
 888                  */
 889                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 890                         state->enter_s2idle = acpi_idle_enter_s2idle;
 891
 892                 count++;
 893                 if (count == CPUIDLE_STATE_MAX)
 894                         break;
 895         }
 896
 897         drv->state_count = count;
 898
 899         if (!count)
 900                 return -EINVAL;
 901
 902         return 0;
 903 }
 904
 905 static inline void acpi_processor_cstate_first_run_checks(void)
 906 {
 907         acpi_status status;
 908         static int first_run;
 909
 910         if (first_run)
 911                 return;
 912         dmi_check_system(processor_power_dmi_table);
 913         max_cstate = acpi_processor_cstate_check(max_cstate);
 914         if (max_cstate < ACPI_C_STATES_MAX)
 915                 pr_notice("ACPI: processor limited to max C-state %d\n",
 916                           max_cstate);
 917         first_run++;
 918
 919         if (acpi_gbl_FADT.cst_control && !nocst) {
 920                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 921                                             acpi_gbl_FADT.cst_control, 8);
 922                 if (ACPI_FAILURE(status))
 923                         ACPI_EXCEPTION((AE_INFO, status,
 924                                         "Notifying BIOS of _CST ability failed"));
 925         }
 926 }
 927 #else
 928
 929 static inline int disabled_by_idle_boot_param(void) { return 0; }
 930 static inline void acpi_processor_cstate_first_run_checks(void) { }
 931 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 932 {
 933         return -ENODEV;
 934 }
 935
 936 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 937                                            struct cpuidle_device *dev)
 938 {
 939         return -EINVAL;
 940 }
 941
 942 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 943 {
 944         return -EINVAL;
 945 }
 946
 947 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 948
 949 struct acpi_lpi_states_array {
 950         unsigned int size;
 951         unsigned int composite_states_size;
 952         struct acpi_lpi_state *entries;
 953         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 954 };
 955
 956 static int obj_get_integer(union acpi_object *obj, u32 *value)
 957 {
 958         if (obj->type != ACPI_TYPE_INTEGER)
 959                 return -EINVAL;
 960
 961         *value = obj->integer.value;
 962         return 0;
 963 }
 964
 965 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 966                                        struct acpi_lpi_states_array *info)
 967 {
 968         acpi_status status;
 969         int ret = 0;
 970         int pkg_count, state_idx = 1, loop;
 971         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 972         union acpi_object *lpi_data;
 973         struct acpi_lpi_state *lpi_state;
 974
 975         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 976         if (ACPI_FAILURE(status)) {
 977                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 978                 return -ENODEV;
 979         }
 980
 981         lpi_data = buffer.pointer;
 982
 983         /* There must be at least 4 elements = 3 elements + 1 package */
 984         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 985             lpi_data->package.count < 4) {
 986                 pr_debug("not enough elements in _LPI\n");
 987                 ret = -ENODATA;
 988                 goto end;
 989         }
 990
 991         pkg_count = lpi_data->package.elements[2].integer.value;
 992
 993         /* Validate number of power states. */
 994         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 995                 pr_debug("count given by _LPI is not valid\n");
 996                 ret = -ENODATA;
 997                 goto end;
 998         }
 999
1000         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
1001         if (!lpi_state) {
1002                 ret = -ENOMEM;
1003                 goto end;
1004         }
1005
1006         info->size = pkg_count;
1007         info->entries = lpi_state;
1008
1009         /* LPI States start at index 3 */
1010         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1011                 union acpi_object *element, *pkg_elem, *obj;
1012
1013                 element = &lpi_data->package.elements[loop];
1014                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1015                         continue;
1016
1017                 pkg_elem = element->package.elements;
1018
1019                 obj = pkg_elem + 6;
1020                 if (obj->type == ACPI_TYPE_BUFFER) {
1021                         struct acpi_power_register *reg;
1022
1023                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1024                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1025                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1026                                 continue;
1027
1028                         lpi_state->address = reg->address;
1029                         lpi_state->entry_method =
1030                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1031                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1032                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1033                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1034                         lpi_state->address = obj->integer.value;
1035                 } else {
1036                         continue;
1037                 }
1038
1039                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1040
1041                 obj = pkg_elem + 9;
1042                 if (obj->type == ACPI_TYPE_STRING)
1043                         strlcpy(lpi_state->desc, obj->string.pointer,
1044                                 ACPI_CX_DESC_LEN);
1045
1046                 lpi_state->index = state_idx;
1047                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1048                         pr_debug("No min. residency found, assuming 10 us\n");
1049                         lpi_state->min_residency = 10;
1050                 }
1051
1052                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1053                         pr_debug("No wakeup residency found, assuming 10 us\n");
1054                         lpi_state->wake_latency = 10;
1055                 }
1056
1057                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1058                         lpi_state->flags = 0;
1059
1060                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1061                         lpi_state->arch_flags = 0;
1062
1063                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1064                         lpi_state->res_cnt_freq = 1;
1065
1066                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1067                         lpi_state->enable_parent_state = 0;
1068         }
1069
1070         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1071 end:
1072         kfree(buffer.pointer);
1073         return ret;
1074 }
1075
1076 /*
1077  * flat_state_cnt - the number of composite LPI states after the process of flattening
1078  */
1079 static int flat_state_cnt;
1080
1081 /**
1082  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1083  *
1084  * @local: local LPI state
1085  * @parent: parent LPI state
1086  * @result: composite LPI state
1087  */
1088 static bool combine_lpi_states(struct acpi_lpi_state *local,
1089                                struct acpi_lpi_state *parent,
1090                                struct acpi_lpi_state *result)
1091 {
1092         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1093                 if (!parent->address) /* 0 means autopromotable */
1094                         return false;
1095                 result->address = local->address + parent->address;
1096         } else {
1097                 result->address = parent->address;
1098         }
1099
1100         result->min_residency = max(local->min_residency, parent->min_residency);
1101         result->wake_latency = local->wake_latency + parent->wake_latency;
1102         result->enable_parent_state = parent->enable_parent_state;
1103         result->entry_method = local->entry_method;
1104
1105         result->flags = parent->flags;
1106         result->arch_flags = parent->arch_flags;
1107         result->index = parent->index;
1108
1109         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1110         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1111         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1112         return true;
1113 }
1114
1115 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1116
1117 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1118                                   struct acpi_lpi_state *t)
1119 {
1120         curr_level->composite_states[curr_level->composite_states_size++] = t;
1121 }
1122
1123 static int flatten_lpi_states(struct acpi_processor *pr,
1124                               struct acpi_lpi_states_array *curr_level,
1125                               struct acpi_lpi_states_array *prev_level)
1126 {
1127         int i, j, state_count = curr_level->size;
1128         struct acpi_lpi_state *p, *t = curr_level->entries;
1129
1130         curr_level->composite_states_size = 0;
1131         for (j = 0; j < state_count; j++, t++) {
1132                 struct acpi_lpi_state *flpi;
1133
1134                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1135                         continue;
1136
1137                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1138                         pr_warn("Limiting number of LPI states to max (%d)\n",
1139                                 ACPI_PROCESSOR_MAX_POWER);
1140                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1141                         break;
1142                 }
1143
1144                 flpi = &pr->power.lpi_states[flat_state_cnt];
1145
1146                 if (!prev_level) { /* leaf/processor node */
1147                         memcpy(flpi, t, sizeof(*t));
1148                         stash_composite_state(curr_level, flpi);
1149                         flat_state_cnt++;
1150                         continue;
1151                 }
1152
1153                 for (i = 0; i < prev_level->composite_states_size; i++) {
1154                         p = prev_level->composite_states[i];
1155                         if (t->index <= p->enable_parent_state &&
1156                             combine_lpi_states(p, t, flpi)) {
1157                                 stash_composite_state(curr_level, flpi);
1158                                 flat_state_cnt++;
1159                                 flpi++;
1160                         }
1161                 }
1162         }
1163
1164         kfree(curr_level->entries);
1165         return 0;
1166 }
1167
1168 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1169 {
1170         int ret, i;
1171         acpi_status status;
1172         acpi_handle handle = pr->handle, pr_ahandle;
1173         struct acpi_device *d = NULL;
1174         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1175
1176         if (!osc_pc_lpi_support_confirmed)
1177                 return -EOPNOTSUPP;
1178
1179         if (!acpi_has_method(handle, "_LPI"))
1180                 return -EINVAL;
1181
1182         flat_state_cnt = 0;
1183         prev = &info[0];
1184         curr = &info[1];
1185         handle = pr->handle;
1186         ret = acpi_processor_evaluate_lpi(handle, prev);
1187         if (ret)
1188                 return ret;
1189         flatten_lpi_states(pr, prev, NULL);
1190
1191         status = acpi_get_parent(handle, &pr_ahandle);
1192         while (ACPI_SUCCESS(status)) {
1193                 acpi_bus_get_device(pr_ahandle, &d);
1194                 handle = pr_ahandle;
1195
1196                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1197                         break;
1198
1199                 /* can be optional ? */
1200                 if (!acpi_has_method(handle, "_LPI"))
1201                         break;
1202
1203                 ret = acpi_processor_evaluate_lpi(handle, curr);
1204                 if (ret)
1205                         break;
1206
1207                 /* flatten all the LPI states in this level of hierarchy */
1208                 flatten_lpi_states(pr, curr, prev);
1209
1210                 tmp = prev, prev = curr, curr = tmp;
1211
1212                 status = acpi_get_parent(handle, &pr_ahandle);
1213         }
1214
1215         pr->power.count = flat_state_cnt;
1216         /* reset the index after flattening */
1217         for (i = 0; i < pr->power.count; i++)
1218                 pr->power.lpi_states[i].index = i;
1219
1220         /* Tell driver that _LPI is supported. */
1221         pr->flags.has_lpi = 1;
1222         pr->flags.power = 1;
1223
1224         return 0;
1225 }
1226
1227 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1228 {
1229         return -ENODEV;
1230 }
1231
1232 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1233 {
1234         return -ENODEV;
1235 }
1236
1237 /**
1238  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1239  * @dev: the target CPU
1240  * @drv: cpuidle driver containing cpuidle state info
1241  * @index: index of target state
1242  *
1243  * Return: 0 for success or negative value for error
1244  */
1245 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1246                                struct cpuidle_driver *drv, int index)
1247 {
1248         struct acpi_processor *pr;
1249         struct acpi_lpi_state *lpi;
1250
1251         pr = __this_cpu_read(processors);
1252
1253         if (unlikely(!pr))
1254                 return -EINVAL;
1255
1256         lpi = &pr->power.lpi_states[index];
1257         if (lpi->entry_method == ACPI_CSTATE_FFH)
1258                 return acpi_processor_ffh_lpi_enter(lpi);
1259
1260         return -EINVAL;
1261 }
1262
1263 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1264 {
1265         int i;
1266         struct acpi_lpi_state *lpi;
1267         struct cpuidle_state *state;
1268         struct cpuidle_driver *drv = &acpi_idle_driver;
1269
1270         if (!pr->flags.has_lpi)
1271                 return -EOPNOTSUPP;
1272
1273         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1274                 lpi = &pr->power.lpi_states[i];
1275
1276                 state = &drv->states[i];
1277                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1278                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1279                 state->exit_latency = lpi->wake_latency;
1280                 state->target_residency = lpi->min_residency;
1281                 if (lpi->arch_flags)
1282                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1283                 state->enter = acpi_idle_lpi_enter;
1284                 drv->safe_state_index = i;
1285         }
1286
1287         drv->state_count = i;
1288
1289         return 0;
1290 }
1291
1292 /**
1293  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1294  * global state data i.e. idle routines
1295  *
1296  * @pr: the ACPI processor
1297  */
1298 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1299 {
1300         int i;
1301         struct cpuidle_driver *drv = &acpi_idle_driver;
1302
1303         if (!pr->flags.power_setup_done || !pr->flags.power)
1304                 return -EINVAL;
1305
1306         drv->safe_state_index = -1;
1307         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1308                 drv->states[i].name[0] = '\0';
1309                 drv->states[i].desc[0] = '\0';
1310         }
1311
1312         if (pr->flags.has_lpi)
1313                 return acpi_processor_setup_lpi_states(pr);
1314
1315         return acpi_processor_setup_cstates(pr);
1316 }
1317
1318 /**
1319  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1320  * device i.e. per-cpu data
1321  *
1322  * @pr: the ACPI processor
1323  * @dev : the cpuidle device
1324  */
1325 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1326                                             struct cpuidle_device *dev)
1327 {
1328         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1329                 return -EINVAL;
1330
1331         dev->cpu = pr->id;
1332         if (pr->flags.has_lpi)
1333                 return acpi_processor_ffh_lpi_probe(pr->id);
1334
1335         return acpi_processor_setup_cpuidle_cx(pr, dev);
1336 }
1337
1338 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1339 {
1340         int ret;
1341
1342         ret = acpi_processor_get_lpi_info(pr);
1343         if (ret)
1344                 ret = acpi_processor_get_cstate_info(pr);
1345
1346         return ret;
1347 }
1348
1349 int acpi_processor_hotplug(struct acpi_processor *pr)
1350 {
1351         int ret = 0;
1352         struct cpuidle_device *dev;
1353
1354         if (disabled_by_idle_boot_param())
1355                 return 0;
1356
1357         if (!pr->flags.power_setup_done)
1358                 return -ENODEV;
1359
1360         dev = per_cpu(acpi_cpuidle_device, pr->id);
1361         cpuidle_pause_and_lock();
1362         cpuidle_disable_device(dev);
1363         ret = acpi_processor_get_power_info(pr);
1364         if (!ret && pr->flags.power) {
1365                 acpi_processor_setup_cpuidle_dev(pr, dev);
1366                 ret = cpuidle_enable_device(dev);
1367         }
1368         cpuidle_resume_and_unlock();
1369
1370         return ret;
1371 }
1372
1373 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1374 {
1375         int cpu;
1376         struct acpi_processor *_pr;
1377         struct cpuidle_device *dev;
1378
1379         if (disabled_by_idle_boot_param())
1380                 return 0;
1381
1382         if (!pr->flags.power_setup_done)
1383                 return -ENODEV;
1384
1385         /*
1386          * FIXME:  Design the ACPI notification to make it once per
1387          * system instead of once per-cpu.  This condition is a hack
1388          * to make the code that updates C-States be called once.
1389          */
1390
1391         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1392
1393                 /* Protect against cpu-hotplug */
1394                 get_online_cpus();
1395                 cpuidle_pause_and_lock();
1396
1397                 /* Disable all cpuidle devices */
1398                 for_each_online_cpu(cpu) {
1399                         _pr = per_cpu(processors, cpu);
1400                         if (!_pr || !_pr->flags.power_setup_done)
1401                                 continue;
1402                         dev = per_cpu(acpi_cpuidle_device, cpu);
1403                         cpuidle_disable_device(dev);
1404                 }
1405
1406                 /* Populate Updated C-state information */
1407                 acpi_processor_get_power_info(pr);
1408                 acpi_processor_setup_cpuidle_states(pr);
1409
1410                 /* Enable all cpuidle devices */
1411                 for_each_online_cpu(cpu) {
1412                         _pr = per_cpu(processors, cpu);
1413                         if (!_pr || !_pr->flags.power_setup_done)
1414                                 continue;
1415                         acpi_processor_get_power_info(_pr);
1416                         if (_pr->flags.power) {
1417                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1418                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1419                                 cpuidle_enable_device(dev);
1420                         }
1421                 }
1422                 cpuidle_resume_and_unlock();
1423                 put_online_cpus();
1424         }
1425
1426         return 0;
1427 }
1428
1429 static int acpi_processor_registered;
1430
1431 int acpi_processor_power_init(struct acpi_processor *pr)
1432 {
1433         int retval;
1434         struct cpuidle_device *dev;
1435
1436         if (disabled_by_idle_boot_param())
1437                 return 0;
1438
1439         acpi_processor_cstate_first_run_checks();
1440
1441         if (!acpi_processor_get_power_info(pr))
1442                 pr->flags.power_setup_done = 1;
1443
1444         /*
1445          * Install the idle handler if processor power management is supported.
1446          * Note that we use previously set idle handler will be used on
1447          * platforms that only support C1.
1448          */
1449         if (pr->flags.power) {
1450                 /* Register acpi_idle_driver if not already registered */
1451                 if (!acpi_processor_registered) {
1452                         acpi_processor_setup_cpuidle_states(pr);
1453                         retval = cpuidle_register_driver(&acpi_idle_driver);
1454                         if (retval)
1455                                 return retval;
1456                         pr_debug("%s registered with cpuidle\n",
1457                                  acpi_idle_driver.name);
1458                 }
1459
1460                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1461                 if (!dev)
1462                         return -ENOMEM;
1463                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1464
1465                 acpi_processor_setup_cpuidle_dev(pr, dev);
1466
1467                 /* Register per-cpu cpuidle_device. Cpuidle driver
1468                  * must already be registered before registering device
1469                  */
1470                 retval = cpuidle_register_device(dev);
1471                 if (retval) {
1472                         if (acpi_processor_registered == 0)
1473                                 cpuidle_unregister_driver(&acpi_idle_driver);
1474                         return retval;
1475                 }
1476                 acpi_processor_registered++;
1477         }
1478         return 0;
1479 }
1480
1481 int acpi_processor_power_exit(struct acpi_processor *pr)
1482 {
1483         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1484
1485         if (disabled_by_idle_boot_param())
1486                 return 0;
1487
1488         if (pr->flags.power) {
1489                 cpuidle_unregister_device(dev);
1490                 acpi_processor_registered--;
1491                 if (acpi_processor_registered == 0)
1492                         cpuidle_unregister_driver(&acpi_idle_driver);
1493         }
1494
1495         pr->flags.power_setup_done = 0;
1496         return 0;
1497 }