drivers/acpi/processor_idle.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * processor_idle - idle state submodule to the ACPI processor driver
   4  *
   5  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   6  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   7  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
   8  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   9  *                      - Added processor hotplug support
  10  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  11  *                      - Added support for C3 on SMP
  12  */
  13 #define pr_fmt(fmt) "ACPI: " fmt
  14
  15 #include <linux/module.h>
  16 #include <linux/acpi.h>
  17 #include <linux/dmi.h>
  18 #include <linux/sched.h>       /* need_resched() */
  19 #include <linux/tick.h>
  20 #include <linux/cpuidle.h>
  21 #include <linux/cpu.h>
  22 #include <acpi/processor.h>
  23
  24 /*
  25  * Include the apic definitions for x86 to have the APIC timer related defines
  26  * available also for UP (on SMP it gets magically included via linux/smp.h).
  27  * asm/acpi.h is not an option, as it would require more include magic. Also
  28  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  29  */
  30 #ifdef CONFIG_X86
  31 #include <asm/apic.h>
  32 #endif
  33
  34 #define ACPI_PROCESSOR_CLASS            "processor"
  35 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  36 ACPI_MODULE_NAME("processor_idle");
  37
  38 #define ACPI_IDLE_STATE_START   (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX) ? 1 : 0)
  39
  40 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  41 module_param(max_cstate, uint, 0000);
  42 static unsigned int nocst __read_mostly;
  43 module_param(nocst, uint, 0000);
  44 static int bm_check_disable __read_mostly;
  45 module_param(bm_check_disable, uint, 0000);
  46
  47 static unsigned int latency_factor __read_mostly = 2;
  48 module_param(latency_factor, uint, 0644);
  49
  50 static DEFINE_PER_CPU(struct cpuidle_device *, acpi_cpuidle_device);
  51
  52 struct cpuidle_driver acpi_idle_driver = {
  53         .name =         "acpi_idle",
  54         .owner =        THIS_MODULE,
  55 };
  56
  57 #ifdef CONFIG_ACPI_PROCESSOR_CSTATE
  58 static
  59 DEFINE_PER_CPU(struct acpi_processor_cx * [CPUIDLE_STATE_MAX], acpi_cstate);
  60
  61 static int disabled_by_idle_boot_param(void)
  62 {
  63         return boot_option_idle_override == IDLE_POLL ||
  64                 boot_option_idle_override == IDLE_HALT;
  65 }
  66
  67 /*
  68  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  69  * For now disable this. Probably a bug somewhere else.
  70  *
  71  * To skip this limit, boot/load with a large max_cstate limit.
  72  */
  73 static int set_max_cstate(const struct dmi_system_id *id)
  74 {
  75         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
  76                 return 0;
  77
  78         pr_notice("%s detected - limiting to C%ld max_cstate."
  79                   " Override with \"processor.max_cstate=%d\"\n", id->ident,
  80                   (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
  81
  82         max_cstate = (long)id->driver_data;
  83
  84         return 0;
  85 }
  86
  87 static const struct dmi_system_id processor_power_dmi_table[] = {
  88         { set_max_cstate, "Clevo 5600D", {
  89           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
  90           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
  91          (void *)2},
  92         { set_max_cstate, "Pavilion zv5000", {
  93           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
  94           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
  95          (void *)1},
  96         { set_max_cstate, "Asus L8400B", {
  97           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
  98           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
  99          (void *)1},
 100         {},
 101 };
 102
 103
 104 /*
 105  * Callers should disable interrupts before the call and enable
 106  * interrupts after return.
 107  */
 108 static void __cpuidle acpi_safe_halt(void)
 109 {
 110         if (!tif_need_resched()) {
 111                 safe_halt();
 112                 local_irq_disable();
 113         }
 114 }
 115
 116 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 117
 118 /*
 119  * Some BIOS implementations switch to C3 in the published C2 state.
 120  * This seems to be a common problem on AMD boxen, but other vendors
 121  * are affected too. We pick the most conservative approach: we assume
 122  * that the local APIC stops in both C2 and C3.
 123  */
 124 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 125                                    struct acpi_processor_cx *cx)
 126 {
 127         struct acpi_processor_power *pwr = &pr->power;
 128         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 129
 130         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 131                 return;
 132
 133         if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E))
 134                 type = ACPI_STATE_C1;
 135
 136         /*
 137          * Check, if one of the previous states already marked the lapic
 138          * unstable
 139          */
 140         if (pwr->timer_broadcast_on_state < state)
 141                 return;
 142
 143         if (cx->type >= type)
 144                 pr->power.timer_broadcast_on_state = state;
 145 }
 146
 147 static void __lapic_timer_propagate_broadcast(void *arg)
 148 {
 149         struct acpi_processor *pr = (struct acpi_processor *) arg;
 150
 151         if (pr->power.timer_broadcast_on_state < INT_MAX)
 152                 tick_broadcast_enable();
 153         else
 154                 tick_broadcast_disable();
 155 }
 156
 157 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 158 {
 159         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 160                                  (void *)pr, 1);
 161 }
 162
 163 /* Power(C) State timer broadcast control */
 164 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 165                                        struct acpi_processor_cx *cx,
 166                                        int broadcast)
 167 {
 168         int state = cx - pr->power.states;
 169
 170         if (state >= pr->power.timer_broadcast_on_state) {
 171                 if (broadcast)
 172                         tick_broadcast_enter();
 173                 else
 174                         tick_broadcast_exit();
 175         }
 176 }
 177
 178 #else
 179
 180 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 181                                    struct acpi_processor_cx *cstate) { }
 182 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 183 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 184                                        struct acpi_processor_cx *cx,
 185                                        int broadcast)
 186 {
 187 }
 188
 189 #endif
 190
 191 #if defined(CONFIG_X86)
 192 static void tsc_check_state(int state)
 193 {
 194         switch (boot_cpu_data.x86_vendor) {
 195         case X86_VENDOR_HYGON:
 196         case X86_VENDOR_AMD:
 197         case X86_VENDOR_INTEL:
 198         case X86_VENDOR_CENTAUR:
 199         case X86_VENDOR_ZHAOXIN:
 200                 /*
 201                  * AMD Fam10h TSC will tick in all
 202                  * C/P/S0/S1 states when this bit is set.
 203                  */
 204                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 205                         return;
 206
 207                 /*FALL THROUGH*/
 208         default:
 209                 /* TSC could halt in idle, so notify users */
 210                 if (state > ACPI_STATE_C1)
 211                         mark_tsc_unstable("TSC halts in idle");
 212         }
 213 }
 214 #else
 215 static void tsc_check_state(int state) { return; }
 216 #endif
 217
 218 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 219 {
 220
 221         if (!pr->pblk)
 222                 return -ENODEV;
 223
 224         /* if info is obtained from pblk/fadt, type equals state */
 225         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 226         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 227
 228 #ifndef CONFIG_HOTPLUG_CPU
 229         /*
 230          * Check for P_LVL2_UP flag before entering C2 and above on
 231          * an SMP system.
 232          */
 233         if ((num_online_cpus() > 1) &&
 234             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 235                 return -ENODEV;
 236 #endif
 237
 238         /* determine C2 and C3 address from pblk */
 239         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 240         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 241
 242         /* determine latencies from FADT */
 243         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 244         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 245
 246         /*
 247          * FADT specified C2 latency must be less than or equal to
 248          * 100 microseconds.
 249          */
 250         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 251                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 252                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 253                 /* invalidate C2 */
 254                 pr->power.states[ACPI_STATE_C2].address = 0;
 255         }
 256
 257         /*
 258          * FADT supplied C3 latency must be less than or equal to
 259          * 1000 microseconds.
 260          */
 261         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 262                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 263                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 264                 /* invalidate C3 */
 265                 pr->power.states[ACPI_STATE_C3].address = 0;
 266         }
 267
 268         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 269                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 270                           pr->power.states[ACPI_STATE_C2].address,
 271                           pr->power.states[ACPI_STATE_C3].address));
 272
 273         snprintf(pr->power.states[ACPI_STATE_C2].desc,
 274                          ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
 275                          pr->power.states[ACPI_STATE_C2].address);
 276         snprintf(pr->power.states[ACPI_STATE_C3].desc,
 277                          ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
 278                          pr->power.states[ACPI_STATE_C3].address);
 279
 280         return 0;
 281 }
 282
 283 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 284 {
 285         if (!pr->power.states[ACPI_STATE_C1].valid) {
 286                 /* set the first C-State to C1 */
 287                 /* all processors need to support C1 */
 288                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 289                 pr->power.states[ACPI_STATE_C1].valid = 1;
 290                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 291
 292                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
 293                          ACPI_CX_DESC_LEN, "ACPI HLT");
 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 static void wait_for_freeze(void)
 646 {
 647 #ifdef  CONFIG_X86
 648         /* No delay is needed if we are in guest */
 649         if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
 650                 return;
 651 #endif
 652         /* Dummy wait op - must do something useless after P_LVL2 read
 653            because chipsets cannot guarantee that STPCLK# signal
 654            gets asserted in time to freeze execution properly. */
 655         inl(acpi_gbl_FADT.xpm_timer_block.address);
 656 }
 657
 658 /**
 659  * acpi_idle_do_entry - enter idle state using the appropriate method
 660  * @cx: cstate data
 661  *
 662  * Caller disables interrupt before call and enables interrupt after return.
 663  */
 664 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 665 {
 666         if (cx->entry_method == ACPI_CSTATE_FFH) {
 667                 /* Call into architectural FFH based C-state */
 668                 acpi_processor_ffh_cstate_enter(cx);
 669         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 670                 acpi_safe_halt();
 671         } else {
 672                 /* IO port based C-state */
 673                 inb(cx->address);
 674                 wait_for_freeze();
 675         }
 676 }
 677
 678 /**
 679  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 680  * @dev: the target CPU
 681  * @index: the index of suggested state
 682  */
 683 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 684 {
 685         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 686
 687         ACPI_FLUSH_CPU_CACHE();
 688
 689         while (1) {
 690
 691                 if (cx->entry_method == ACPI_CSTATE_HALT)
 692                         safe_halt();
 693                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 694                         inb(cx->address);
 695                         wait_for_freeze();
 696                 } else
 697                         return -ENODEV;
 698         }
 699
 700         /* Never reached */
 701         return 0;
 702 }
 703
 704 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 705 {
 706         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 707                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 708 }
 709
 710 static int c3_cpu_count;
 711 static DEFINE_RAW_SPINLOCK(c3_lock);
 712
 713 /**
 714  * acpi_idle_enter_bm - enters C3 with proper BM handling
 715  * @pr: Target processor
 716  * @cx: Target state context
 717  * @timer_bc: Whether or not to change timer mode to broadcast
 718  */
 719 static void acpi_idle_enter_bm(struct acpi_processor *pr,
 720                                struct acpi_processor_cx *cx, bool timer_bc)
 721 {
 722         acpi_unlazy_tlb(smp_processor_id());
 723
 724         /*
 725          * Must be done before busmaster disable as we might need to
 726          * access HPET !
 727          */
 728         if (timer_bc)
 729                 lapic_timer_state_broadcast(pr, cx, 1);
 730
 731         /*
 732          * disable bus master
 733          * bm_check implies we need ARB_DIS
 734          * bm_control implies whether we can do ARB_DIS
 735          *
 736          * That leaves a case where bm_check is set and bm_control is
 737          * not set. In that case we cannot do much, we enter C3
 738          * without doing anything.
 739          */
 740         if (pr->flags.bm_control) {
 741                 raw_spin_lock(&c3_lock);
 742                 c3_cpu_count++;
 743                 /* Disable bus master arbitration when all CPUs are in C3 */
 744                 if (c3_cpu_count == num_online_cpus())
 745                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 746                 raw_spin_unlock(&c3_lock);
 747         }
 748
 749         acpi_idle_do_entry(cx);
 750
 751         /* Re-enable bus master arbitration */
 752         if (pr->flags.bm_control) {
 753                 raw_spin_lock(&c3_lock);
 754                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 755                 c3_cpu_count--;
 756                 raw_spin_unlock(&c3_lock);
 757         }
 758
 759         if (timer_bc)
 760                 lapic_timer_state_broadcast(pr, cx, 0);
 761 }
 762
 763 static int acpi_idle_enter(struct cpuidle_device *dev,
 764                            struct cpuidle_driver *drv, int index)
 765 {
 766         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 767         struct acpi_processor *pr;
 768
 769         pr = __this_cpu_read(processors);
 770         if (unlikely(!pr))
 771                 return -EINVAL;
 772
 773         if (cx->type != ACPI_STATE_C1) {
 774                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 775                         index = ACPI_IDLE_STATE_START;
 776                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 777                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 778                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 779                                 acpi_idle_enter_bm(pr, cx, true);
 780                                 return index;
 781                         } else if (drv->safe_state_index >= 0) {
 782                                 index = drv->safe_state_index;
 783                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 784                         } else {
 785                                 acpi_safe_halt();
 786                                 return -EBUSY;
 787                         }
 788                 }
 789         }
 790
 791         lapic_timer_state_broadcast(pr, cx, 1);
 792
 793         if (cx->type == ACPI_STATE_C3)
 794                 ACPI_FLUSH_CPU_CACHE();
 795
 796         acpi_idle_do_entry(cx);
 797
 798         lapic_timer_state_broadcast(pr, cx, 0);
 799
 800         return index;
 801 }
 802
 803 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 804                                    struct cpuidle_driver *drv, int index)
 805 {
 806         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 807
 808         if (cx->type == ACPI_STATE_C3) {
 809                 struct acpi_processor *pr = __this_cpu_read(processors);
 810
 811                 if (unlikely(!pr))
 812                         return;
 813
 814                 if (pr->flags.bm_check) {
 815                         acpi_idle_enter_bm(pr, cx, false);
 816                         return;
 817                 } else {
 818                         ACPI_FLUSH_CPU_CACHE();
 819                 }
 820         }
 821         acpi_idle_do_entry(cx);
 822 }
 823
 824 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 825                                            struct cpuidle_device *dev)
 826 {
 827         int i, count = ACPI_IDLE_STATE_START;
 828         struct acpi_processor_cx *cx;
 829
 830         if (max_cstate == 0)
 831                 max_cstate = 1;
 832
 833         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 834                 cx = &pr->power.states[i];
 835
 836                 if (!cx->valid)
 837                         continue;
 838
 839                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 840
 841                 count++;
 842                 if (count == CPUIDLE_STATE_MAX)
 843                         break;
 844         }
 845
 846         if (!count)
 847                 return -EINVAL;
 848
 849         return 0;
 850 }
 851
 852 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 853 {
 854         int i, count;
 855         struct acpi_processor_cx *cx;
 856         struct cpuidle_state *state;
 857         struct cpuidle_driver *drv = &acpi_idle_driver;
 858
 859         if (max_cstate == 0)
 860                 max_cstate = 1;
 861
 862         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 863                 cpuidle_poll_state_init(drv);
 864                 count = 1;
 865         } else {
 866                 count = 0;
 867         }
 868
 869         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 870                 cx = &pr->power.states[i];
 871
 872                 if (!cx->valid)
 873                         continue;
 874
 875                 state = &drv->states[count];
 876                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 877                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 878                 state->exit_latency = cx->latency;
 879                 state->target_residency = cx->latency * latency_factor;
 880                 state->enter = acpi_idle_enter;
 881
 882                 state->flags = 0;
 883                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 884                         state->enter_dead = acpi_idle_play_dead;
 885                         drv->safe_state_index = count;
 886                 }
 887                 /*
 888                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 889                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 890                  * particularly interesting from the suspend-to-idle angle, so
 891                  * avoid C1 and the situations in which we may need to fall back
 892                  * to it altogether.
 893                  */
 894                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 895                         state->enter_s2idle = acpi_idle_enter_s2idle;
 896
 897                 count++;
 898                 if (count == CPUIDLE_STATE_MAX)
 899                         break;
 900         }
 901
 902         drv->state_count = count;
 903
 904         if (!count)
 905                 return -EINVAL;
 906
 907         return 0;
 908 }
 909
 910 static inline void acpi_processor_cstate_first_run_checks(void)
 911 {
 912         acpi_status status;
 913         static int first_run;
 914
 915         if (first_run)
 916                 return;
 917         dmi_check_system(processor_power_dmi_table);
 918         max_cstate = acpi_processor_cstate_check(max_cstate);
 919         if (max_cstate < ACPI_C_STATES_MAX)
 920                 pr_notice("ACPI: processor limited to max C-state %d\n",
 921                           max_cstate);
 922         first_run++;
 923
 924         if (acpi_gbl_FADT.cst_control && !nocst) {
 925                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 926                                             acpi_gbl_FADT.cst_control, 8);
 927                 if (ACPI_FAILURE(status))
 928                         ACPI_EXCEPTION((AE_INFO, status,
 929                                         "Notifying BIOS of _CST ability failed"));
 930         }
 931 }
 932 #else
 933
 934 static inline int disabled_by_idle_boot_param(void) { return 0; }
 935 static inline void acpi_processor_cstate_first_run_checks(void) { }
 936 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 937 {
 938         return -ENODEV;
 939 }
 940
 941 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 942                                            struct cpuidle_device *dev)
 943 {
 944         return -EINVAL;
 945 }
 946
 947 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 948 {
 949         return -EINVAL;
 950 }
 951
 952 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 953
 954 struct acpi_lpi_states_array {
 955         unsigned int size;
 956         unsigned int composite_states_size;
 957         struct acpi_lpi_state *entries;
 958         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 959 };
 960
 961 static int obj_get_integer(union acpi_object *obj, u32 *value)
 962 {
 963         if (obj->type != ACPI_TYPE_INTEGER)
 964                 return -EINVAL;
 965
 966         *value = obj->integer.value;
 967         return 0;
 968 }
 969
 970 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 971                                        struct acpi_lpi_states_array *info)
 972 {
 973         acpi_status status;
 974         int ret = 0;
 975         int pkg_count, state_idx = 1, loop;
 976         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 977         union acpi_object *lpi_data;
 978         struct acpi_lpi_state *lpi_state;
 979
 980         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 981         if (ACPI_FAILURE(status)) {
 982                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 983                 return -ENODEV;
 984         }
 985
 986         lpi_data = buffer.pointer;
 987
 988         /* There must be at least 4 elements = 3 elements + 1 package */
 989         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 990             lpi_data->package.count < 4) {
 991                 pr_debug("not enough elements in _LPI\n");
 992                 ret = -ENODATA;
 993                 goto end;
 994         }
 995
 996         pkg_count = lpi_data->package.elements[2].integer.value;
 997
 998         /* Validate number of power states. */
 999         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
1000                 pr_debug("count given by _LPI is not valid\n");
1001                 ret = -ENODATA;
1002                 goto end;
1003         }
1004
1005         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
1006         if (!lpi_state) {
1007                 ret = -ENOMEM;
1008                 goto end;
1009         }
1010
1011         info->size = pkg_count;
1012         info->entries = lpi_state;
1013
1014         /* LPI States start at index 3 */
1015         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1016                 union acpi_object *element, *pkg_elem, *obj;
1017
1018                 element = &lpi_data->package.elements[loop];
1019                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1020                         continue;
1021
1022                 pkg_elem = element->package.elements;
1023
1024                 obj = pkg_elem + 6;
1025                 if (obj->type == ACPI_TYPE_BUFFER) {
1026                         struct acpi_power_register *reg;
1027
1028                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1029                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1030                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1031                                 continue;
1032
1033                         lpi_state->address = reg->address;
1034                         lpi_state->entry_method =
1035                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1036                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1037                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1038                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1039                         lpi_state->address = obj->integer.value;
1040                 } else {
1041                         continue;
1042                 }
1043
1044                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1045
1046                 obj = pkg_elem + 9;
1047                 if (obj->type == ACPI_TYPE_STRING)
1048                         strlcpy(lpi_state->desc, obj->string.pointer,
1049                                 ACPI_CX_DESC_LEN);
1050
1051                 lpi_state->index = state_idx;
1052                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1053                         pr_debug("No min. residency found, assuming 10 us\n");
1054                         lpi_state->min_residency = 10;
1055                 }
1056
1057                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1058                         pr_debug("No wakeup residency found, assuming 10 us\n");
1059                         lpi_state->wake_latency = 10;
1060                 }
1061
1062                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1063                         lpi_state->flags = 0;
1064
1065                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1066                         lpi_state->arch_flags = 0;
1067
1068                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1069                         lpi_state->res_cnt_freq = 1;
1070
1071                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1072                         lpi_state->enable_parent_state = 0;
1073         }
1074
1075         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1076 end:
1077         kfree(buffer.pointer);
1078         return ret;
1079 }
1080
1081 /*
1082  * flat_state_cnt - the number of composite LPI states after the process of flattening
1083  */
1084 static int flat_state_cnt;
1085
1086 /**
1087  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1088  *
1089  * @local: local LPI state
1090  * @parent: parent LPI state
1091  * @result: composite LPI state
1092  */
1093 static bool combine_lpi_states(struct acpi_lpi_state *local,
1094                                struct acpi_lpi_state *parent,
1095                                struct acpi_lpi_state *result)
1096 {
1097         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1098                 if (!parent->address) /* 0 means autopromotable */
1099                         return false;
1100                 result->address = local->address + parent->address;
1101         } else {
1102                 result->address = parent->address;
1103         }
1104
1105         result->min_residency = max(local->min_residency, parent->min_residency);
1106         result->wake_latency = local->wake_latency + parent->wake_latency;
1107         result->enable_parent_state = parent->enable_parent_state;
1108         result->entry_method = local->entry_method;
1109
1110         result->flags = parent->flags;
1111         result->arch_flags = parent->arch_flags;
1112         result->index = parent->index;
1113
1114         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1115         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1116         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1117         return true;
1118 }
1119
1120 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1121
1122 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1123                                   struct acpi_lpi_state *t)
1124 {
1125         curr_level->composite_states[curr_level->composite_states_size++] = t;
1126 }
1127
1128 static int flatten_lpi_states(struct acpi_processor *pr,
1129                               struct acpi_lpi_states_array *curr_level,
1130                               struct acpi_lpi_states_array *prev_level)
1131 {
1132         int i, j, state_count = curr_level->size;
1133         struct acpi_lpi_state *p, *t = curr_level->entries;
1134
1135         curr_level->composite_states_size = 0;
1136         for (j = 0; j < state_count; j++, t++) {
1137                 struct acpi_lpi_state *flpi;
1138
1139                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1140                         continue;
1141
1142                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1143                         pr_warn("Limiting number of LPI states to max (%d)\n",
1144                                 ACPI_PROCESSOR_MAX_POWER);
1145                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1146                         break;
1147                 }
1148
1149                 flpi = &pr->power.lpi_states[flat_state_cnt];
1150
1151                 if (!prev_level) { /* leaf/processor node */
1152                         memcpy(flpi, t, sizeof(*t));
1153                         stash_composite_state(curr_level, flpi);
1154                         flat_state_cnt++;
1155                         continue;
1156                 }
1157
1158                 for (i = 0; i < prev_level->composite_states_size; i++) {
1159                         p = prev_level->composite_states[i];
1160                         if (t->index <= p->enable_parent_state &&
1161                             combine_lpi_states(p, t, flpi)) {
1162                                 stash_composite_state(curr_level, flpi);
1163                                 flat_state_cnt++;
1164                                 flpi++;
1165                         }
1166                 }
1167         }
1168
1169         kfree(curr_level->entries);
1170         return 0;
1171 }
1172
1173 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1174 {
1175         int ret, i;
1176         acpi_status status;
1177         acpi_handle handle = pr->handle, pr_ahandle;
1178         struct acpi_device *d = NULL;
1179         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1180
1181         if (!osc_pc_lpi_support_confirmed)
1182                 return -EOPNOTSUPP;
1183
1184         if (!acpi_has_method(handle, "_LPI"))
1185                 return -EINVAL;
1186
1187         flat_state_cnt = 0;
1188         prev = &info[0];
1189         curr = &info[1];
1190         handle = pr->handle;
1191         ret = acpi_processor_evaluate_lpi(handle, prev);
1192         if (ret)
1193                 return ret;
1194         flatten_lpi_states(pr, prev, NULL);
1195
1196         status = acpi_get_parent(handle, &pr_ahandle);
1197         while (ACPI_SUCCESS(status)) {
1198                 acpi_bus_get_device(pr_ahandle, &d);
1199                 handle = pr_ahandle;
1200
1201                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1202                         break;
1203
1204                 /* can be optional ? */
1205                 if (!acpi_has_method(handle, "_LPI"))
1206                         break;
1207
1208                 ret = acpi_processor_evaluate_lpi(handle, curr);
1209                 if (ret)
1210                         break;
1211
1212                 /* flatten all the LPI states in this level of hierarchy */
1213                 flatten_lpi_states(pr, curr, prev);
1214
1215                 tmp = prev, prev = curr, curr = tmp;
1216
1217                 status = acpi_get_parent(handle, &pr_ahandle);
1218         }
1219
1220         pr->power.count = flat_state_cnt;
1221         /* reset the index after flattening */
1222         for (i = 0; i < pr->power.count; i++)
1223                 pr->power.lpi_states[i].index = i;
1224
1225         /* Tell driver that _LPI is supported. */
1226         pr->flags.has_lpi = 1;
1227         pr->flags.power = 1;
1228
1229         return 0;
1230 }
1231
1232 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1233 {
1234         return -ENODEV;
1235 }
1236
1237 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1238 {
1239         return -ENODEV;
1240 }
1241
1242 /**
1243  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1244  * @dev: the target CPU
1245  * @drv: cpuidle driver containing cpuidle state info
1246  * @index: index of target state
1247  *
1248  * Return: 0 for success or negative value for error
1249  */
1250 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1251                                struct cpuidle_driver *drv, int index)
1252 {
1253         struct acpi_processor *pr;
1254         struct acpi_lpi_state *lpi;
1255
1256         pr = __this_cpu_read(processors);
1257
1258         if (unlikely(!pr))
1259                 return -EINVAL;
1260
1261         lpi = &pr->power.lpi_states[index];
1262         if (lpi->entry_method == ACPI_CSTATE_FFH)
1263                 return acpi_processor_ffh_lpi_enter(lpi);
1264
1265         return -EINVAL;
1266 }
1267
1268 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1269 {
1270         int i;
1271         struct acpi_lpi_state *lpi;
1272         struct cpuidle_state *state;
1273         struct cpuidle_driver *drv = &acpi_idle_driver;
1274
1275         if (!pr->flags.has_lpi)
1276                 return -EOPNOTSUPP;
1277
1278         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1279                 lpi = &pr->power.lpi_states[i];
1280
1281                 state = &drv->states[i];
1282                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1283                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1284                 state->exit_latency = lpi->wake_latency;
1285                 state->target_residency = lpi->min_residency;
1286                 if (lpi->arch_flags)
1287                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1288                 state->enter = acpi_idle_lpi_enter;
1289                 drv->safe_state_index = i;
1290         }
1291
1292         drv->state_count = i;
1293
1294         return 0;
1295 }
1296
1297 /**
1298  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1299  * global state data i.e. idle routines
1300  *
1301  * @pr: the ACPI processor
1302  */
1303 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1304 {
1305         int i;
1306         struct cpuidle_driver *drv = &acpi_idle_driver;
1307
1308         if (!pr->flags.power_setup_done || !pr->flags.power)
1309                 return -EINVAL;
1310
1311         drv->safe_state_index = -1;
1312         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1313                 drv->states[i].name[0] = '\0';
1314                 drv->states[i].desc[0] = '\0';
1315         }
1316
1317         if (pr->flags.has_lpi)
1318                 return acpi_processor_setup_lpi_states(pr);
1319
1320         return acpi_processor_setup_cstates(pr);
1321 }
1322
1323 /**
1324  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1325  * device i.e. per-cpu data
1326  *
1327  * @pr: the ACPI processor
1328  * @dev : the cpuidle device
1329  */
1330 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1331                                             struct cpuidle_device *dev)
1332 {
1333         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1334                 return -EINVAL;
1335
1336         dev->cpu = pr->id;
1337         if (pr->flags.has_lpi)
1338                 return acpi_processor_ffh_lpi_probe(pr->id);
1339
1340         return acpi_processor_setup_cpuidle_cx(pr, dev);
1341 }
1342
1343 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1344 {
1345         int ret;
1346
1347         ret = acpi_processor_get_lpi_info(pr);
1348         if (ret)
1349                 ret = acpi_processor_get_cstate_info(pr);
1350
1351         return ret;
1352 }
1353
1354 int acpi_processor_hotplug(struct acpi_processor *pr)
1355 {
1356         int ret = 0;
1357         struct cpuidle_device *dev;
1358
1359         if (disabled_by_idle_boot_param())
1360                 return 0;
1361
1362         if (!pr->flags.power_setup_done)
1363                 return -ENODEV;
1364
1365         dev = per_cpu(acpi_cpuidle_device, pr->id);
1366         cpuidle_pause_and_lock();
1367         cpuidle_disable_device(dev);
1368         ret = acpi_processor_get_power_info(pr);
1369         if (!ret && pr->flags.power) {
1370                 acpi_processor_setup_cpuidle_dev(pr, dev);
1371                 ret = cpuidle_enable_device(dev);
1372         }
1373         cpuidle_resume_and_unlock();
1374
1375         return ret;
1376 }
1377
1378 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1379 {
1380         int cpu;
1381         struct acpi_processor *_pr;
1382         struct cpuidle_device *dev;
1383
1384         if (disabled_by_idle_boot_param())
1385                 return 0;
1386
1387         if (!pr->flags.power_setup_done)
1388                 return -ENODEV;
1389
1390         /*
1391          * FIXME:  Design the ACPI notification to make it once per
1392          * system instead of once per-cpu.  This condition is a hack
1393          * to make the code that updates C-States be called once.
1394          */
1395
1396         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1397
1398                 /* Protect against cpu-hotplug */
1399                 get_online_cpus();
1400                 cpuidle_pause_and_lock();
1401
1402                 /* Disable all cpuidle devices */
1403                 for_each_online_cpu(cpu) {
1404                         _pr = per_cpu(processors, cpu);
1405                         if (!_pr || !_pr->flags.power_setup_done)
1406                                 continue;
1407                         dev = per_cpu(acpi_cpuidle_device, cpu);
1408                         cpuidle_disable_device(dev);
1409                 }
1410
1411                 /* Populate Updated C-state information */
1412                 acpi_processor_get_power_info(pr);
1413                 acpi_processor_setup_cpuidle_states(pr);
1414
1415                 /* Enable all cpuidle devices */
1416                 for_each_online_cpu(cpu) {
1417                         _pr = per_cpu(processors, cpu);
1418                         if (!_pr || !_pr->flags.power_setup_done)
1419                                 continue;
1420                         acpi_processor_get_power_info(_pr);
1421                         if (_pr->flags.power) {
1422                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1423                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1424                                 cpuidle_enable_device(dev);
1425                         }
1426                 }
1427                 cpuidle_resume_and_unlock();
1428                 put_online_cpus();
1429         }
1430
1431         return 0;
1432 }
1433
1434 static int acpi_processor_registered;
1435
1436 int acpi_processor_power_init(struct acpi_processor *pr)
1437 {
1438         int retval;
1439         struct cpuidle_device *dev;
1440
1441         if (disabled_by_idle_boot_param())
1442                 return 0;
1443
1444         acpi_processor_cstate_first_run_checks();
1445
1446         if (!acpi_processor_get_power_info(pr))
1447                 pr->flags.power_setup_done = 1;
1448
1449         /*
1450          * Install the idle handler if processor power management is supported.
1451          * Note that we use previously set idle handler will be used on
1452          * platforms that only support C1.
1453          */
1454         if (pr->flags.power) {
1455                 /* Register acpi_idle_driver if not already registered */
1456                 if (!acpi_processor_registered) {
1457                         acpi_processor_setup_cpuidle_states(pr);
1458                         retval = cpuidle_register_driver(&acpi_idle_driver);
1459                         if (retval)
1460                                 return retval;
1461                         pr_debug("%s registered with cpuidle\n",
1462                                  acpi_idle_driver.name);
1463                 }
1464
1465                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1466                 if (!dev)
1467                         return -ENOMEM;
1468                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1469
1470                 acpi_processor_setup_cpuidle_dev(pr, dev);
1471
1472                 /* Register per-cpu cpuidle_device. Cpuidle driver
1473                  * must already be registered before registering device
1474                  */
1475                 retval = cpuidle_register_device(dev);
1476                 if (retval) {
1477                         if (acpi_processor_registered == 0)
1478                                 cpuidle_unregister_driver(&acpi_idle_driver);
1479                         return retval;
1480                 }
1481                 acpi_processor_registered++;
1482         }
1483         return 0;
1484 }
1485
1486 int acpi_processor_power_exit(struct acpi_processor *pr)
1487 {
1488         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1489
1490         if (disabled_by_idle_boot_param())
1491                 return 0;
1492
1493         if (pr->flags.power) {
1494                 cpuidle_unregister_device(dev);
1495                 acpi_processor_registered--;
1496                 if (acpi_processor_registered == 0)
1497                         cpuidle_unregister_driver(&acpi_idle_driver);
1498         }
1499
1500         pr->flags.power_setup_done = 0;
1501         return 0;
1502 }