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         acpi_unlazy_tlb(smp_processor_id());
 714
 715         /*
 716          * Must be done before busmaster disable as we might need to
 717          * access HPET !
 718          */
 719         if (timer_bc)
 720                 lapic_timer_state_broadcast(pr, cx, 1);
 721
 722         /*
 723          * disable bus master
 724          * bm_check implies we need ARB_DIS
 725          * bm_control implies whether we can do ARB_DIS
 726          *
 727          * That leaves a case where bm_check is set and bm_control is
 728          * not set. In that case we cannot do much, we enter C3
 729          * without doing anything.
 730          */
 731         if (pr->flags.bm_control) {
 732                 raw_spin_lock(&c3_lock);
 733                 c3_cpu_count++;
 734                 /* Disable bus master arbitration when all CPUs are in C3 */
 735                 if (c3_cpu_count == num_online_cpus())
 736                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 737                 raw_spin_unlock(&c3_lock);
 738         }
 739
 740         acpi_idle_do_entry(cx);
 741
 742         /* Re-enable bus master arbitration */
 743         if (pr->flags.bm_control) {
 744                 raw_spin_lock(&c3_lock);
 745                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 746                 c3_cpu_count--;
 747                 raw_spin_unlock(&c3_lock);
 748         }
 749
 750         if (timer_bc)
 751                 lapic_timer_state_broadcast(pr, cx, 0);
 752 }
 753
 754 static int acpi_idle_enter(struct cpuidle_device *dev,
 755                            struct cpuidle_driver *drv, int index)
 756 {
 757         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 758         struct acpi_processor *pr;
 759
 760         pr = __this_cpu_read(processors);
 761         if (unlikely(!pr))
 762                 return -EINVAL;
 763
 764         if (cx->type != ACPI_STATE_C1) {
 765                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 766                         index = ACPI_IDLE_STATE_START;
 767                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 768                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 769                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 770                                 acpi_idle_enter_bm(pr, cx, true);
 771                                 return index;
 772                         } else if (drv->safe_state_index >= 0) {
 773                                 index = drv->safe_state_index;
 774                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 775                         } else {
 776                                 acpi_safe_halt();
 777                                 return -EBUSY;
 778                         }
 779                 }
 780         }
 781
 782         lapic_timer_state_broadcast(pr, cx, 1);
 783
 784         if (cx->type == ACPI_STATE_C3)
 785                 ACPI_FLUSH_CPU_CACHE();
 786
 787         acpi_idle_do_entry(cx);
 788
 789         lapic_timer_state_broadcast(pr, cx, 0);
 790
 791         return index;
 792 }
 793
 794 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 795                                    struct cpuidle_driver *drv, int index)
 796 {
 797         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 798
 799         if (cx->type == ACPI_STATE_C3) {
 800                 struct acpi_processor *pr = __this_cpu_read(processors);
 801
 802                 if (unlikely(!pr))
 803                         return;
 804
 805                 if (pr->flags.bm_check) {
 806                         acpi_idle_enter_bm(pr, cx, false);
 807                         return;
 808                 } else {
 809                         ACPI_FLUSH_CPU_CACHE();
 810                 }
 811         }
 812         acpi_idle_do_entry(cx);
 813 }
 814
 815 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 816                                            struct cpuidle_device *dev)
 817 {
 818         int i, count = ACPI_IDLE_STATE_START;
 819         struct acpi_processor_cx *cx;
 820
 821         if (max_cstate == 0)
 822                 max_cstate = 1;
 823
 824         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 825                 cx = &pr->power.states[i];
 826
 827                 if (!cx->valid)
 828                         continue;
 829
 830                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 831
 832                 count++;
 833                 if (count == CPUIDLE_STATE_MAX)
 834                         break;
 835         }
 836
 837         if (!count)
 838                 return -EINVAL;
 839
 840         return 0;
 841 }
 842
 843 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 844 {
 845         int i, count;
 846         struct acpi_processor_cx *cx;
 847         struct cpuidle_state *state;
 848         struct cpuidle_driver *drv = &acpi_idle_driver;
 849
 850         if (max_cstate == 0)
 851                 max_cstate = 1;
 852
 853         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 854                 cpuidle_poll_state_init(drv);
 855                 count = 1;
 856         } else {
 857                 count = 0;
 858         }
 859
 860         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 861                 cx = &pr->power.states[i];
 862
 863                 if (!cx->valid)
 864                         continue;
 865
 866                 state = &drv->states[count];
 867                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 868                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 869                 state->exit_latency = cx->latency;
 870                 state->target_residency = cx->latency * latency_factor;
 871                 state->enter = acpi_idle_enter;
 872
 873                 state->flags = 0;
 874                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 875                         state->enter_dead = acpi_idle_play_dead;
 876                         drv->safe_state_index = count;
 877                 }
 878                 /*
 879                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 880                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 881                  * particularly interesting from the suspend-to-idle angle, so
 882                  * avoid C1 and the situations in which we may need to fall back
 883                  * to it altogether.
 884                  */
 885                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 886                         state->enter_s2idle = acpi_idle_enter_s2idle;
 887
 888                 count++;
 889                 if (count == CPUIDLE_STATE_MAX)
 890                         break;
 891         }
 892
 893         drv->state_count = count;
 894
 895         if (!count)
 896                 return -EINVAL;
 897
 898         return 0;
 899 }
 900
 901 static inline void acpi_processor_cstate_first_run_checks(void)
 902 {
 903         acpi_status status;
 904         static int first_run;
 905
 906         if (first_run)
 907                 return;
 908         dmi_check_system(processor_power_dmi_table);
 909         max_cstate = acpi_processor_cstate_check(max_cstate);
 910         if (max_cstate < ACPI_C_STATES_MAX)
 911                 pr_notice("ACPI: processor limited to max C-state %d\n",
 912                           max_cstate);
 913         first_run++;
 914
 915         if (acpi_gbl_FADT.cst_control && !nocst) {
 916                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 917                                             acpi_gbl_FADT.cst_control, 8);
 918                 if (ACPI_FAILURE(status))
 919                         ACPI_EXCEPTION((AE_INFO, status,
 920                                         "Notifying BIOS of _CST ability failed"));
 921         }
 922 }
 923 #else
 924
 925 static inline int disabled_by_idle_boot_param(void) { return 0; }
 926 static inline void acpi_processor_cstate_first_run_checks(void) { }
 927 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 928 {
 929         return -ENODEV;
 930 }
 931
 932 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 933                                            struct cpuidle_device *dev)
 934 {
 935         return -EINVAL;
 936 }
 937
 938 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 939 {
 940         return -EINVAL;
 941 }
 942
 943 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 944
 945 struct acpi_lpi_states_array {
 946         unsigned int size;
 947         unsigned int composite_states_size;
 948         struct acpi_lpi_state *entries;
 949         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 950 };
 951
 952 static int obj_get_integer(union acpi_object *obj, u32 *value)
 953 {
 954         if (obj->type != ACPI_TYPE_INTEGER)
 955                 return -EINVAL;
 956
 957         *value = obj->integer.value;
 958         return 0;
 959 }
 960
 961 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 962                                        struct acpi_lpi_states_array *info)
 963 {
 964         acpi_status status;
 965         int ret = 0;
 966         int pkg_count, state_idx = 1, loop;
 967         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 968         union acpi_object *lpi_data;
 969         struct acpi_lpi_state *lpi_state;
 970
 971         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 972         if (ACPI_FAILURE(status)) {
 973                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 974                 return -ENODEV;
 975         }
 976
 977         lpi_data = buffer.pointer;
 978
 979         /* There must be at least 4 elements = 3 elements + 1 package */
 980         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 981             lpi_data->package.count < 4) {
 982                 pr_debug("not enough elements in _LPI\n");
 983                 ret = -ENODATA;
 984                 goto end;
 985         }
 986
 987         pkg_count = lpi_data->package.elements[2].integer.value;
 988
 989         /* Validate number of power states. */
 990         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 991                 pr_debug("count given by _LPI is not valid\n");
 992                 ret = -ENODATA;
 993                 goto end;
 994         }
 995
 996         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 997         if (!lpi_state) {
 998                 ret = -ENOMEM;
 999                 goto end;
1000         }
1001
1002         info->size = pkg_count;
1003         info->entries = lpi_state;
1004
1005         /* LPI States start at index 3 */
1006         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1007                 union acpi_object *element, *pkg_elem, *obj;
1008
1009                 element = &lpi_data->package.elements[loop];
1010                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1011                         continue;
1012
1013                 pkg_elem = element->package.elements;
1014
1015                 obj = pkg_elem + 6;
1016                 if (obj->type == ACPI_TYPE_BUFFER) {
1017                         struct acpi_power_register *reg;
1018
1019                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1020                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1021                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1022                                 continue;
1023
1024                         lpi_state->address = reg->address;
1025                         lpi_state->entry_method =
1026                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1027                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1028                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1029                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1030                         lpi_state->address = obj->integer.value;
1031                 } else {
1032                         continue;
1033                 }
1034
1035                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1036
1037                 obj = pkg_elem + 9;
1038                 if (obj->type == ACPI_TYPE_STRING)
1039                         strlcpy(lpi_state->desc, obj->string.pointer,
1040                                 ACPI_CX_DESC_LEN);
1041
1042                 lpi_state->index = state_idx;
1043                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1044                         pr_debug("No min. residency found, assuming 10 us\n");
1045                         lpi_state->min_residency = 10;
1046                 }
1047
1048                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1049                         pr_debug("No wakeup residency found, assuming 10 us\n");
1050                         lpi_state->wake_latency = 10;
1051                 }
1052
1053                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1054                         lpi_state->flags = 0;
1055
1056                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1057                         lpi_state->arch_flags = 0;
1058
1059                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1060                         lpi_state->res_cnt_freq = 1;
1061
1062                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1063                         lpi_state->enable_parent_state = 0;
1064         }
1065
1066         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1067 end:
1068         kfree(buffer.pointer);
1069         return ret;
1070 }
1071
1072 /*
1073  * flat_state_cnt - the number of composite LPI states after the process of flattening
1074  */
1075 static int flat_state_cnt;
1076
1077 /**
1078  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1079  *
1080  * @local: local LPI state
1081  * @parent: parent LPI state
1082  * @result: composite LPI state
1083  */
1084 static bool combine_lpi_states(struct acpi_lpi_state *local,
1085                                struct acpi_lpi_state *parent,
1086                                struct acpi_lpi_state *result)
1087 {
1088         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1089                 if (!parent->address) /* 0 means autopromotable */
1090                         return false;
1091                 result->address = local->address + parent->address;
1092         } else {
1093                 result->address = parent->address;
1094         }
1095
1096         result->min_residency = max(local->min_residency, parent->min_residency);
1097         result->wake_latency = local->wake_latency + parent->wake_latency;
1098         result->enable_parent_state = parent->enable_parent_state;
1099         result->entry_method = local->entry_method;
1100
1101         result->flags = parent->flags;
1102         result->arch_flags = parent->arch_flags;
1103         result->index = parent->index;
1104
1105         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1106         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1107         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1108         return true;
1109 }
1110
1111 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1112
1113 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1114                                   struct acpi_lpi_state *t)
1115 {
1116         curr_level->composite_states[curr_level->composite_states_size++] = t;
1117 }
1118
1119 static int flatten_lpi_states(struct acpi_processor *pr,
1120                               struct acpi_lpi_states_array *curr_level,
1121                               struct acpi_lpi_states_array *prev_level)
1122 {
1123         int i, j, state_count = curr_level->size;
1124         struct acpi_lpi_state *p, *t = curr_level->entries;
1125
1126         curr_level->composite_states_size = 0;
1127         for (j = 0; j < state_count; j++, t++) {
1128                 struct acpi_lpi_state *flpi;
1129
1130                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1131                         continue;
1132
1133                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1134                         pr_warn("Limiting number of LPI states to max (%d)\n",
1135                                 ACPI_PROCESSOR_MAX_POWER);
1136                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1137                         break;
1138                 }
1139
1140                 flpi = &pr->power.lpi_states[flat_state_cnt];
1141
1142                 if (!prev_level) { /* leaf/processor node */
1143                         memcpy(flpi, t, sizeof(*t));
1144                         stash_composite_state(curr_level, flpi);
1145                         flat_state_cnt++;
1146                         continue;
1147                 }
1148
1149                 for (i = 0; i < prev_level->composite_states_size; i++) {
1150                         p = prev_level->composite_states[i];
1151                         if (t->index <= p->enable_parent_state &&
1152                             combine_lpi_states(p, t, flpi)) {
1153                                 stash_composite_state(curr_level, flpi);
1154                                 flat_state_cnt++;
1155                                 flpi++;
1156                         }
1157                 }
1158         }
1159
1160         kfree(curr_level->entries);
1161         return 0;
1162 }
1163
1164 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1165 {
1166         int ret, i;
1167         acpi_status status;
1168         acpi_handle handle = pr->handle, pr_ahandle;
1169         struct acpi_device *d = NULL;
1170         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1171
1172         if (!osc_pc_lpi_support_confirmed)
1173                 return -EOPNOTSUPP;
1174
1175         if (!acpi_has_method(handle, "_LPI"))
1176                 return -EINVAL;
1177
1178         flat_state_cnt = 0;
1179         prev = &info[0];
1180         curr = &info[1];
1181         handle = pr->handle;
1182         ret = acpi_processor_evaluate_lpi(handle, prev);
1183         if (ret)
1184                 return ret;
1185         flatten_lpi_states(pr, prev, NULL);
1186
1187         status = acpi_get_parent(handle, &pr_ahandle);
1188         while (ACPI_SUCCESS(status)) {
1189                 acpi_bus_get_device(pr_ahandle, &d);
1190                 handle = pr_ahandle;
1191
1192                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1193                         break;
1194
1195                 /* can be optional ? */
1196                 if (!acpi_has_method(handle, "_LPI"))
1197                         break;
1198
1199                 ret = acpi_processor_evaluate_lpi(handle, curr);
1200                 if (ret)
1201                         break;
1202
1203                 /* flatten all the LPI states in this level of hierarchy */
1204                 flatten_lpi_states(pr, curr, prev);
1205
1206                 tmp = prev, prev = curr, curr = tmp;
1207
1208                 status = acpi_get_parent(handle, &pr_ahandle);
1209         }
1210
1211         pr->power.count = flat_state_cnt;
1212         /* reset the index after flattening */
1213         for (i = 0; i < pr->power.count; i++)
1214                 pr->power.lpi_states[i].index = i;
1215
1216         /* Tell driver that _LPI is supported. */
1217         pr->flags.has_lpi = 1;
1218         pr->flags.power = 1;
1219
1220         return 0;
1221 }
1222
1223 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1224 {
1225         return -ENODEV;
1226 }
1227
1228 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1229 {
1230         return -ENODEV;
1231 }
1232
1233 /**
1234  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1235  * @dev: the target CPU
1236  * @drv: cpuidle driver containing cpuidle state info
1237  * @index: index of target state
1238  *
1239  * Return: 0 for success or negative value for error
1240  */
1241 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1242                                struct cpuidle_driver *drv, int index)
1243 {
1244         struct acpi_processor *pr;
1245         struct acpi_lpi_state *lpi;
1246
1247         pr = __this_cpu_read(processors);
1248
1249         if (unlikely(!pr))
1250                 return -EINVAL;
1251
1252         lpi = &pr->power.lpi_states[index];
1253         if (lpi->entry_method == ACPI_CSTATE_FFH)
1254                 return acpi_processor_ffh_lpi_enter(lpi);
1255
1256         return -EINVAL;
1257 }
1258
1259 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1260 {
1261         int i;
1262         struct acpi_lpi_state *lpi;
1263         struct cpuidle_state *state;
1264         struct cpuidle_driver *drv = &acpi_idle_driver;
1265
1266         if (!pr->flags.has_lpi)
1267                 return -EOPNOTSUPP;
1268
1269         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1270                 lpi = &pr->power.lpi_states[i];
1271
1272                 state = &drv->states[i];
1273                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1274                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1275                 state->exit_latency = lpi->wake_latency;
1276                 state->target_residency = lpi->min_residency;
1277                 if (lpi->arch_flags)
1278                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1279                 state->enter = acpi_idle_lpi_enter;
1280                 drv->safe_state_index = i;
1281         }
1282
1283         drv->state_count = i;
1284
1285         return 0;
1286 }
1287
1288 /**
1289  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1290  * global state data i.e. idle routines
1291  *
1292  * @pr: the ACPI processor
1293  */
1294 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1295 {
1296         int i;
1297         struct cpuidle_driver *drv = &acpi_idle_driver;
1298
1299         if (!pr->flags.power_setup_done || !pr->flags.power)
1300                 return -EINVAL;
1301
1302         drv->safe_state_index = -1;
1303         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1304                 drv->states[i].name[0] = '\0';
1305                 drv->states[i].desc[0] = '\0';
1306         }
1307
1308         if (pr->flags.has_lpi)
1309                 return acpi_processor_setup_lpi_states(pr);
1310
1311         return acpi_processor_setup_cstates(pr);
1312 }
1313
1314 /**
1315  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1316  * device i.e. per-cpu data
1317  *
1318  * @pr: the ACPI processor
1319  * @dev : the cpuidle device
1320  */
1321 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1322                                             struct cpuidle_device *dev)
1323 {
1324         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1325                 return -EINVAL;
1326
1327         dev->cpu = pr->id;
1328         if (pr->flags.has_lpi)
1329                 return acpi_processor_ffh_lpi_probe(pr->id);
1330
1331         return acpi_processor_setup_cpuidle_cx(pr, dev);
1332 }
1333
1334 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1335 {
1336         int ret;
1337
1338         ret = acpi_processor_get_lpi_info(pr);
1339         if (ret)
1340                 ret = acpi_processor_get_cstate_info(pr);
1341
1342         return ret;
1343 }
1344
1345 int acpi_processor_hotplug(struct acpi_processor *pr)
1346 {
1347         int ret = 0;
1348         struct cpuidle_device *dev;
1349
1350         if (disabled_by_idle_boot_param())
1351                 return 0;
1352
1353         if (!pr->flags.power_setup_done)
1354                 return -ENODEV;
1355
1356         dev = per_cpu(acpi_cpuidle_device, pr->id);
1357         cpuidle_pause_and_lock();
1358         cpuidle_disable_device(dev);
1359         ret = acpi_processor_get_power_info(pr);
1360         if (!ret && pr->flags.power) {
1361                 acpi_processor_setup_cpuidle_dev(pr, dev);
1362                 ret = cpuidle_enable_device(dev);
1363         }
1364         cpuidle_resume_and_unlock();
1365
1366         return ret;
1367 }
1368
1369 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1370 {
1371         int cpu;
1372         struct acpi_processor *_pr;
1373         struct cpuidle_device *dev;
1374
1375         if (disabled_by_idle_boot_param())
1376                 return 0;
1377
1378         if (!pr->flags.power_setup_done)
1379                 return -ENODEV;
1380
1381         /*
1382          * FIXME:  Design the ACPI notification to make it once per
1383          * system instead of once per-cpu.  This condition is a hack
1384          * to make the code that updates C-States be called once.
1385          */
1386
1387         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1388
1389                 /* Protect against cpu-hotplug */
1390                 get_online_cpus();
1391                 cpuidle_pause_and_lock();
1392
1393                 /* Disable all cpuidle devices */
1394                 for_each_online_cpu(cpu) {
1395                         _pr = per_cpu(processors, cpu);
1396                         if (!_pr || !_pr->flags.power_setup_done)
1397                                 continue;
1398                         dev = per_cpu(acpi_cpuidle_device, cpu);
1399                         cpuidle_disable_device(dev);
1400                 }
1401
1402                 /* Populate Updated C-state information */
1403                 acpi_processor_get_power_info(pr);
1404                 acpi_processor_setup_cpuidle_states(pr);
1405
1406                 /* Enable all cpuidle devices */
1407                 for_each_online_cpu(cpu) {
1408                         _pr = per_cpu(processors, cpu);
1409                         if (!_pr || !_pr->flags.power_setup_done)
1410                                 continue;
1411                         acpi_processor_get_power_info(_pr);
1412                         if (_pr->flags.power) {
1413                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1414                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1415                                 cpuidle_enable_device(dev);
1416                         }
1417                 }
1418                 cpuidle_resume_and_unlock();
1419                 put_online_cpus();
1420         }
1421
1422         return 0;
1423 }
1424
1425 static int acpi_processor_registered;
1426
1427 int acpi_processor_power_init(struct acpi_processor *pr)
1428 {
1429         int retval;
1430         struct cpuidle_device *dev;
1431
1432         if (disabled_by_idle_boot_param())
1433                 return 0;
1434
1435         acpi_processor_cstate_first_run_checks();
1436
1437         if (!acpi_processor_get_power_info(pr))
1438                 pr->flags.power_setup_done = 1;
1439
1440         /*
1441          * Install the idle handler if processor power management is supported.
1442          * Note that we use previously set idle handler will be used on
1443          * platforms that only support C1.
1444          */
1445         if (pr->flags.power) {
1446                 /* Register acpi_idle_driver if not already registered */
1447                 if (!acpi_processor_registered) {
1448                         acpi_processor_setup_cpuidle_states(pr);
1449                         retval = cpuidle_register_driver(&acpi_idle_driver);
1450                         if (retval)
1451                                 return retval;
1452                         pr_debug("%s registered with cpuidle\n",
1453                                  acpi_idle_driver.name);
1454                 }
1455
1456                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1457                 if (!dev)
1458                         return -ENOMEM;
1459                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1460
1461                 acpi_processor_setup_cpuidle_dev(pr, dev);
1462
1463                 /* Register per-cpu cpuidle_device. Cpuidle driver
1464                  * must already be registered before registering device
1465                  */
1466                 retval = cpuidle_register_device(dev);
1467                 if (retval) {
1468                         if (acpi_processor_registered == 0)
1469                                 cpuidle_unregister_driver(&acpi_idle_driver);
1470                         return retval;
1471                 }
1472                 acpi_processor_registered++;
1473         }
1474         return 0;
1475 }
1476
1477 int acpi_processor_power_exit(struct acpi_processor *pr)
1478 {
1479         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1480
1481         if (disabled_by_idle_boot_param())
1482                 return 0;
1483
1484         if (pr->flags.power) {
1485                 cpuidle_unregister_device(dev);
1486                 acpi_processor_registered--;
1487                 if (acpi_processor_registered == 0)
1488                         cpuidle_unregister_driver(&acpi_idle_driver);
1489         }
1490
1491         pr->flags.power_setup_done = 0;
1492         return 0;
1493 }