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                 /*
 200                  * AMD Fam10h TSC will tick in all
 201                  * C/P/S0/S1 states when this bit is set.
 202                  */
 203                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 204                         return;
 205
 206                 /*FALL THROUGH*/
 207         default:
 208                 /* TSC could halt in idle, so notify users */
 209                 if (state > ACPI_STATE_C1)
 210                         mark_tsc_unstable("TSC halts in idle");
 211         }
 212 }
 213 #else
 214 static void tsc_check_state(int state) { return; }
 215 #endif
 216
 217 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 218 {
 219
 220         if (!pr->pblk)
 221                 return -ENODEV;
 222
 223         /* if info is obtained from pblk/fadt, type equals state */
 224         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 225         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 226
 227 #ifndef CONFIG_HOTPLUG_CPU
 228         /*
 229          * Check for P_LVL2_UP flag before entering C2 and above on
 230          * an SMP system.
 231          */
 232         if ((num_online_cpus() > 1) &&
 233             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 234                 return -ENODEV;
 235 #endif
 236
 237         /* determine C2 and C3 address from pblk */
 238         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 239         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 240
 241         /* determine latencies from FADT */
 242         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.c2_latency;
 243         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.c3_latency;
 244
 245         /*
 246          * FADT specified C2 latency must be less than or equal to
 247          * 100 microseconds.
 248          */
 249         if (acpi_gbl_FADT.c2_latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 250                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 251                         "C2 latency too large [%d]\n", acpi_gbl_FADT.c2_latency));
 252                 /* invalidate C2 */
 253                 pr->power.states[ACPI_STATE_C2].address = 0;
 254         }
 255
 256         /*
 257          * FADT supplied C3 latency must be less than or equal to
 258          * 1000 microseconds.
 259          */
 260         if (acpi_gbl_FADT.c3_latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 261                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 262                         "C3 latency too large [%d]\n", acpi_gbl_FADT.c3_latency));
 263                 /* invalidate C3 */
 264                 pr->power.states[ACPI_STATE_C3].address = 0;
 265         }
 266
 267         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 268                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 269                           pr->power.states[ACPI_STATE_C2].address,
 270                           pr->power.states[ACPI_STATE_C3].address));
 271
 272         snprintf(pr->power.states[ACPI_STATE_C2].desc,
 273                          ACPI_CX_DESC_LEN, "ACPI P_LVL2 IOPORT 0x%x",
 274                          pr->power.states[ACPI_STATE_C2].address);
 275         snprintf(pr->power.states[ACPI_STATE_C3].desc,
 276                          ACPI_CX_DESC_LEN, "ACPI P_LVL3 IOPORT 0x%x",
 277                          pr->power.states[ACPI_STATE_C3].address);
 278
 279         return 0;
 280 }
 281
 282 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 283 {
 284         if (!pr->power.states[ACPI_STATE_C1].valid) {
 285                 /* set the first C-State to C1 */
 286                 /* all processors need to support C1 */
 287                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 288                 pr->power.states[ACPI_STATE_C1].valid = 1;
 289                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 290
 291                 snprintf(pr->power.states[ACPI_STATE_C1].desc,
 292                          ACPI_CX_DESC_LEN, "ACPI HLT");
 293         }
 294         /* the C0 state only exists as a filler in our array */
 295         pr->power.states[ACPI_STATE_C0].valid = 1;
 296         return 0;
 297 }
 298
 299 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 300 {
 301         acpi_status status;
 302         u64 count;
 303         int current_count;
 304         int i, ret = 0;
 305         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 306         union acpi_object *cst;
 307
 308         if (nocst)
 309                 return -ENODEV;
 310
 311         current_count = 0;
 312
 313         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 314         if (ACPI_FAILURE(status)) {
 315                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 316                 return -ENODEV;
 317         }
 318
 319         cst = buffer.pointer;
 320
 321         /* There must be at least 2 elements */
 322         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 323                 pr_err("not enough elements in _CST\n");
 324                 ret = -EFAULT;
 325                 goto end;
 326         }
 327
 328         count = cst->package.elements[0].integer.value;
 329
 330         /* Validate number of power states. */
 331         if (count < 1 || count != cst->package.count - 1) {
 332                 pr_err("count given by _CST is not valid\n");
 333                 ret = -EFAULT;
 334                 goto end;
 335         }
 336
 337         /* Tell driver that at least _CST is supported. */
 338         pr->flags.has_cst = 1;
 339
 340         for (i = 1; i <= count; i++) {
 341                 union acpi_object *element;
 342                 union acpi_object *obj;
 343                 struct acpi_power_register *reg;
 344                 struct acpi_processor_cx cx;
 345
 346                 memset(&cx, 0, sizeof(cx));
 347
 348                 element = &(cst->package.elements[i]);
 349                 if (element->type != ACPI_TYPE_PACKAGE)
 350                         continue;
 351
 352                 if (element->package.count != 4)
 353                         continue;
 354
 355                 obj = &(element->package.elements[0]);
 356
 357                 if (obj->type != ACPI_TYPE_BUFFER)
 358                         continue;
 359
 360                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 361
 362                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 363                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 364                         continue;
 365
 366                 /* There should be an easy way to extract an integer... */
 367                 obj = &(element->package.elements[1]);
 368                 if (obj->type != ACPI_TYPE_INTEGER)
 369                         continue;
 370
 371                 cx.type = obj->integer.value;
 372                 /*
 373                  * Some buggy BIOSes won't list C1 in _CST -
 374                  * Let acpi_processor_get_power_info_default() handle them later
 375                  */
 376                 if (i == 1 && cx.type != ACPI_STATE_C1)
 377                         current_count++;
 378
 379                 cx.address = reg->address;
 380                 cx.index = current_count + 1;
 381
 382                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 383                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 384                         if (acpi_processor_ffh_cstate_probe
 385                                         (pr->id, &cx, reg) == 0) {
 386                                 cx.entry_method = ACPI_CSTATE_FFH;
 387                         } else if (cx.type == ACPI_STATE_C1) {
 388                                 /*
 389                                  * C1 is a special case where FIXED_HARDWARE
 390                                  * can be handled in non-MWAIT way as well.
 391                                  * In that case, save this _CST entry info.
 392                                  * Otherwise, ignore this info and continue.
 393                                  */
 394                                 cx.entry_method = ACPI_CSTATE_HALT;
 395                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 396                         } else {
 397                                 continue;
 398                         }
 399                         if (cx.type == ACPI_STATE_C1 &&
 400                             (boot_option_idle_override == IDLE_NOMWAIT)) {
 401                                 /*
 402                                  * In most cases the C1 space_id obtained from
 403                                  * _CST object is FIXED_HARDWARE access mode.
 404                                  * But when the option of idle=halt is added,
 405                                  * the entry_method type should be changed from
 406                                  * CSTATE_FFH to CSTATE_HALT.
 407                                  * When the option of idle=nomwait is added,
 408                                  * the C1 entry_method type should be
 409                                  * CSTATE_HALT.
 410                                  */
 411                                 cx.entry_method = ACPI_CSTATE_HALT;
 412                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 413                         }
 414                 } else {
 415                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 416                                  cx.address);
 417                 }
 418
 419                 if (cx.type == ACPI_STATE_C1) {
 420                         cx.valid = 1;
 421                 }
 422
 423                 obj = &(element->package.elements[2]);
 424                 if (obj->type != ACPI_TYPE_INTEGER)
 425                         continue;
 426
 427                 cx.latency = obj->integer.value;
 428
 429                 obj = &(element->package.elements[3]);
 430                 if (obj->type != ACPI_TYPE_INTEGER)
 431                         continue;
 432
 433                 current_count++;
 434                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 435
 436                 /*
 437                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 438                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 439                  */
 440                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 441                         pr_warn("Limiting number of power states to max (%d)\n",
 442                                 ACPI_PROCESSOR_MAX_POWER);
 443                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 444                         break;
 445                 }
 446         }
 447
 448         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 449                           current_count));
 450
 451         /* Validate number of power states discovered */
 452         if (current_count < 2)
 453                 ret = -EFAULT;
 454
 455       end:
 456         kfree(buffer.pointer);
 457
 458         return ret;
 459 }
 460
 461 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 462                                            struct acpi_processor_cx *cx)
 463 {
 464         static int bm_check_flag = -1;
 465         static int bm_control_flag = -1;
 466
 467
 468         if (!cx->address)
 469                 return;
 470
 471         /*
 472          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 473          * DMA transfers are used by any ISA device to avoid livelock.
 474          * Note that we could disable Type-F DMA (as recommended by
 475          * the erratum), but this is known to disrupt certain ISA
 476          * devices thus we take the conservative approach.
 477          */
 478         else if (errata.piix4.fdma) {
 479                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 480                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 481                 return;
 482         }
 483
 484         /* All the logic here assumes flags.bm_check is same across all CPUs */
 485         if (bm_check_flag == -1) {
 486                 /* Determine whether bm_check is needed based on CPU  */
 487                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 488                 bm_check_flag = pr->flags.bm_check;
 489                 bm_control_flag = pr->flags.bm_control;
 490         } else {
 491                 pr->flags.bm_check = bm_check_flag;
 492                 pr->flags.bm_control = bm_control_flag;
 493         }
 494
 495         if (pr->flags.bm_check) {
 496                 if (!pr->flags.bm_control) {
 497                         if (pr->flags.has_cst != 1) {
 498                                 /* bus mastering control is necessary */
 499                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 500                                         "C3 support requires BM control\n"));
 501                                 return;
 502                         } else {
 503                                 /* Here we enter C3 without bus mastering */
 504                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 505                                         "C3 support without BM control\n"));
 506                         }
 507                 }
 508         } else {
 509                 /*
 510                  * WBINVD should be set in fadt, for C3 state to be
 511                  * supported on when bm_check is not required.
 512                  */
 513                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 514                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 515                                           "Cache invalidation should work properly"
 516                                           " for C3 to be enabled on SMP systems\n"));
 517                         return;
 518                 }
 519         }
 520
 521         /*
 522          * Otherwise we've met all of our C3 requirements.
 523          * Normalize the C3 latency to expidite policy.  Enable
 524          * checking of bus mastering status (bm_check) so we can
 525          * use this in our C3 policy
 526          */
 527         cx->valid = 1;
 528
 529         /*
 530          * On older chipsets, BM_RLD needs to be set
 531          * in order for Bus Master activity to wake the
 532          * system from C3.  Newer chipsets handle DMA
 533          * during C3 automatically and BM_RLD is a NOP.
 534          * In either case, the proper way to
 535          * handle BM_RLD is to set it and leave it set.
 536          */
 537         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 538
 539         return;
 540 }
 541
 542 static int acpi_processor_power_verify(struct acpi_processor *pr)
 543 {
 544         unsigned int i;
 545         unsigned int working = 0;
 546
 547         pr->power.timer_broadcast_on_state = INT_MAX;
 548
 549         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 550                 struct acpi_processor_cx *cx = &pr->power.states[i];
 551
 552                 switch (cx->type) {
 553                 case ACPI_STATE_C1:
 554                         cx->valid = 1;
 555                         break;
 556
 557                 case ACPI_STATE_C2:
 558                         if (!cx->address)
 559                                 break;
 560                         cx->valid = 1;
 561                         break;
 562
 563                 case ACPI_STATE_C3:
 564                         acpi_processor_power_verify_c3(pr, cx);
 565                         break;
 566                 }
 567                 if (!cx->valid)
 568                         continue;
 569
 570                 lapic_timer_check_state(i, pr, cx);
 571                 tsc_check_state(cx->type);
 572                 working++;
 573         }
 574
 575         lapic_timer_propagate_broadcast(pr);
 576
 577         return (working);
 578 }
 579
 580 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 581 {
 582         unsigned int i;
 583         int result;
 584
 585
 586         /* NOTE: the idle thread may not be running while calling
 587          * this function */
 588
 589         /* Zero initialize all the C-states info. */
 590         memset(pr->power.states, 0, sizeof(pr->power.states));
 591
 592         result = acpi_processor_get_power_info_cst(pr);
 593         if (result == -ENODEV)
 594                 result = acpi_processor_get_power_info_fadt(pr);
 595
 596         if (result)
 597                 return result;
 598
 599         acpi_processor_get_power_info_default(pr);
 600
 601         pr->power.count = acpi_processor_power_verify(pr);
 602
 603         /*
 604          * if one state of type C2 or C3 is available, mark this
 605          * CPU as being "idle manageable"
 606          */
 607         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 608                 if (pr->power.states[i].valid) {
 609                         pr->power.count = i;
 610                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 611                                 pr->flags.power = 1;
 612                 }
 613         }
 614
 615         return 0;
 616 }
 617
 618 /**
 619  * acpi_idle_bm_check - checks if bus master activity was detected
 620  */
 621 static int acpi_idle_bm_check(void)
 622 {
 623         u32 bm_status = 0;
 624
 625         if (bm_check_disable)
 626                 return 0;
 627
 628         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 629         if (bm_status)
 630                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 631         /*
 632          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 633          * the true state of bus mastering activity; forcing us to
 634          * manually check the BMIDEA bit of each IDE channel.
 635          */
 636         else if (errata.piix4.bmisx) {
 637                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 638                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 639                         bm_status = 1;
 640         }
 641         return bm_status;
 642 }
 643
 644 /**
 645  * acpi_idle_do_entry - enter idle state using the appropriate method
 646  * @cx: cstate data
 647  *
 648  * Caller disables interrupt before call and enables interrupt after return.
 649  */
 650 static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
 651 {
 652         if (cx->entry_method == ACPI_CSTATE_FFH) {
 653                 /* Call into architectural FFH based C-state */
 654                 acpi_processor_ffh_cstate_enter(cx);
 655         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 656                 acpi_safe_halt();
 657         } else {
 658                 /* IO port based C-state */
 659                 inb(cx->address);
 660                 /* Dummy wait op - must do something useless after P_LVL2 read
 661                    because chipsets cannot guarantee that STPCLK# signal
 662                    gets asserted in time to freeze execution properly. */
 663                 inl(acpi_gbl_FADT.xpm_timer_block.address);
 664         }
 665 }
 666
 667 /**
 668  * acpi_idle_play_dead - enters an ACPI state for long-term idle (i.e. off-lining)
 669  * @dev: the target CPU
 670  * @index: the index of suggested state
 671  */
 672 static int acpi_idle_play_dead(struct cpuidle_device *dev, int index)
 673 {
 674         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 675
 676         ACPI_FLUSH_CPU_CACHE();
 677
 678         while (1) {
 679
 680                 if (cx->entry_method == ACPI_CSTATE_HALT)
 681                         safe_halt();
 682                 else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
 683                         inb(cx->address);
 684                         /* See comment in acpi_idle_do_entry() */
 685                         inl(acpi_gbl_FADT.xpm_timer_block.address);
 686                 } else
 687                         return -ENODEV;
 688         }
 689
 690         /* Never reached */
 691         return 0;
 692 }
 693
 694 static bool acpi_idle_fallback_to_c1(struct acpi_processor *pr)
 695 {
 696         return IS_ENABLED(CONFIG_HOTPLUG_CPU) && !pr->flags.has_cst &&
 697                 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED);
 698 }
 699
 700 static int c3_cpu_count;
 701 static DEFINE_RAW_SPINLOCK(c3_lock);
 702
 703 /**
 704  * acpi_idle_enter_bm - enters C3 with proper BM handling
 705  * @pr: Target processor
 706  * @cx: Target state context
 707  * @timer_bc: Whether or not to change timer mode to broadcast
 708  */
 709 static void acpi_idle_enter_bm(struct acpi_processor *pr,
 710                                struct acpi_processor_cx *cx, bool timer_bc)
 711 {
 712         acpi_unlazy_tlb(smp_processor_id());
 713
 714         /*
 715          * Must be done before busmaster disable as we might need to
 716          * access HPET !
 717          */
 718         if (timer_bc)
 719                 lapic_timer_state_broadcast(pr, cx, 1);
 720
 721         /*
 722          * disable bus master
 723          * bm_check implies we need ARB_DIS
 724          * bm_control implies whether we can do ARB_DIS
 725          *
 726          * That leaves a case where bm_check is set and bm_control is
 727          * not set. In that case we cannot do much, we enter C3
 728          * without doing anything.
 729          */
 730         if (pr->flags.bm_control) {
 731                 raw_spin_lock(&c3_lock);
 732                 c3_cpu_count++;
 733                 /* Disable bus master arbitration when all CPUs are in C3 */
 734                 if (c3_cpu_count == num_online_cpus())
 735                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
 736                 raw_spin_unlock(&c3_lock);
 737         }
 738
 739         acpi_idle_do_entry(cx);
 740
 741         /* Re-enable bus master arbitration */
 742         if (pr->flags.bm_control) {
 743                 raw_spin_lock(&c3_lock);
 744                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
 745                 c3_cpu_count--;
 746                 raw_spin_unlock(&c3_lock);
 747         }
 748
 749         if (timer_bc)
 750                 lapic_timer_state_broadcast(pr, cx, 0);
 751 }
 752
 753 static int acpi_idle_enter(struct cpuidle_device *dev,
 754                            struct cpuidle_driver *drv, int index)
 755 {
 756         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 757         struct acpi_processor *pr;
 758
 759         pr = __this_cpu_read(processors);
 760         if (unlikely(!pr))
 761                 return -EINVAL;
 762
 763         if (cx->type != ACPI_STATE_C1) {
 764                 if (acpi_idle_fallback_to_c1(pr) && num_online_cpus() > 1) {
 765                         index = ACPI_IDLE_STATE_START;
 766                         cx = per_cpu(acpi_cstate[index], dev->cpu);
 767                 } else if (cx->type == ACPI_STATE_C3 && pr->flags.bm_check) {
 768                         if (cx->bm_sts_skip || !acpi_idle_bm_check()) {
 769                                 acpi_idle_enter_bm(pr, cx, true);
 770                                 return index;
 771                         } else if (drv->safe_state_index >= 0) {
 772                                 index = drv->safe_state_index;
 773                                 cx = per_cpu(acpi_cstate[index], dev->cpu);
 774                         } else {
 775                                 acpi_safe_halt();
 776                                 return -EBUSY;
 777                         }
 778                 }
 779         }
 780
 781         lapic_timer_state_broadcast(pr, cx, 1);
 782
 783         if (cx->type == ACPI_STATE_C3)
 784                 ACPI_FLUSH_CPU_CACHE();
 785
 786         acpi_idle_do_entry(cx);
 787
 788         lapic_timer_state_broadcast(pr, cx, 0);
 789
 790         return index;
 791 }
 792
 793 static void acpi_idle_enter_s2idle(struct cpuidle_device *dev,
 794                                    struct cpuidle_driver *drv, int index)
 795 {
 796         struct acpi_processor_cx *cx = per_cpu(acpi_cstate[index], dev->cpu);
 797
 798         if (cx->type == ACPI_STATE_C3) {
 799                 struct acpi_processor *pr = __this_cpu_read(processors);
 800
 801                 if (unlikely(!pr))
 802                         return;
 803
 804                 if (pr->flags.bm_check) {
 805                         acpi_idle_enter_bm(pr, cx, false);
 806                         return;
 807                 } else {
 808                         ACPI_FLUSH_CPU_CACHE();
 809                 }
 810         }
 811         acpi_idle_do_entry(cx);
 812 }
 813
 814 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 815                                            struct cpuidle_device *dev)
 816 {
 817         int i, count = ACPI_IDLE_STATE_START;
 818         struct acpi_processor_cx *cx;
 819
 820         if (max_cstate == 0)
 821                 max_cstate = 1;
 822
 823         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 824                 cx = &pr->power.states[i];
 825
 826                 if (!cx->valid)
 827                         continue;
 828
 829                 per_cpu(acpi_cstate[count], dev->cpu) = cx;
 830
 831                 count++;
 832                 if (count == CPUIDLE_STATE_MAX)
 833                         break;
 834         }
 835
 836         if (!count)
 837                 return -EINVAL;
 838
 839         return 0;
 840 }
 841
 842 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 843 {
 844         int i, count;
 845         struct acpi_processor_cx *cx;
 846         struct cpuidle_state *state;
 847         struct cpuidle_driver *drv = &acpi_idle_driver;
 848
 849         if (max_cstate == 0)
 850                 max_cstate = 1;
 851
 852         if (IS_ENABLED(CONFIG_ARCH_HAS_CPU_RELAX)) {
 853                 cpuidle_poll_state_init(drv);
 854                 count = 1;
 855         } else {
 856                 count = 0;
 857         }
 858
 859         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 860                 cx = &pr->power.states[i];
 861
 862                 if (!cx->valid)
 863                         continue;
 864
 865                 state = &drv->states[count];
 866                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
 867                 strlcpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
 868                 state->exit_latency = cx->latency;
 869                 state->target_residency = cx->latency * latency_factor;
 870                 state->enter = acpi_idle_enter;
 871
 872                 state->flags = 0;
 873                 if (cx->type == ACPI_STATE_C1 || cx->type == ACPI_STATE_C2) {
 874                         state->enter_dead = acpi_idle_play_dead;
 875                         drv->safe_state_index = count;
 876                 }
 877                 /*
 878                  * Halt-induced C1 is not good for ->enter_s2idle, because it
 879                  * re-enables interrupts on exit.  Moreover, C1 is generally not
 880                  * particularly interesting from the suspend-to-idle angle, so
 881                  * avoid C1 and the situations in which we may need to fall back
 882                  * to it altogether.
 883                  */
 884                 if (cx->type != ACPI_STATE_C1 && !acpi_idle_fallback_to_c1(pr))
 885                         state->enter_s2idle = acpi_idle_enter_s2idle;
 886
 887                 count++;
 888                 if (count == CPUIDLE_STATE_MAX)
 889                         break;
 890         }
 891
 892         drv->state_count = count;
 893
 894         if (!count)
 895                 return -EINVAL;
 896
 897         return 0;
 898 }
 899
 900 static inline void acpi_processor_cstate_first_run_checks(void)
 901 {
 902         acpi_status status;
 903         static int first_run;
 904
 905         if (first_run)
 906                 return;
 907         dmi_check_system(processor_power_dmi_table);
 908         max_cstate = acpi_processor_cstate_check(max_cstate);
 909         if (max_cstate < ACPI_C_STATES_MAX)
 910                 pr_notice("ACPI: processor limited to max C-state %d\n",
 911                           max_cstate);
 912         first_run++;
 913
 914         if (acpi_gbl_FADT.cst_control && !nocst) {
 915                 status = acpi_os_write_port(acpi_gbl_FADT.smi_command,
 916                                             acpi_gbl_FADT.cst_control, 8);
 917                 if (ACPI_FAILURE(status))
 918                         ACPI_EXCEPTION((AE_INFO, status,
 919                                         "Notifying BIOS of _CST ability failed"));
 920         }
 921 }
 922 #else
 923
 924 static inline int disabled_by_idle_boot_param(void) { return 0; }
 925 static inline void acpi_processor_cstate_first_run_checks(void) { }
 926 static int acpi_processor_get_cstate_info(struct acpi_processor *pr)
 927 {
 928         return -ENODEV;
 929 }
 930
 931 static int acpi_processor_setup_cpuidle_cx(struct acpi_processor *pr,
 932                                            struct cpuidle_device *dev)
 933 {
 934         return -EINVAL;
 935 }
 936
 937 static int acpi_processor_setup_cstates(struct acpi_processor *pr)
 938 {
 939         return -EINVAL;
 940 }
 941
 942 #endif /* CONFIG_ACPI_PROCESSOR_CSTATE */
 943
 944 struct acpi_lpi_states_array {
 945         unsigned int size;
 946         unsigned int composite_states_size;
 947         struct acpi_lpi_state *entries;
 948         struct acpi_lpi_state *composite_states[ACPI_PROCESSOR_MAX_POWER];
 949 };
 950
 951 static int obj_get_integer(union acpi_object *obj, u32 *value)
 952 {
 953         if (obj->type != ACPI_TYPE_INTEGER)
 954                 return -EINVAL;
 955
 956         *value = obj->integer.value;
 957         return 0;
 958 }
 959
 960 static int acpi_processor_evaluate_lpi(acpi_handle handle,
 961                                        struct acpi_lpi_states_array *info)
 962 {
 963         acpi_status status;
 964         int ret = 0;
 965         int pkg_count, state_idx = 1, loop;
 966         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 967         union acpi_object *lpi_data;
 968         struct acpi_lpi_state *lpi_state;
 969
 970         status = acpi_evaluate_object(handle, "_LPI", NULL, &buffer);
 971         if (ACPI_FAILURE(status)) {
 972                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _LPI, giving up\n"));
 973                 return -ENODEV;
 974         }
 975
 976         lpi_data = buffer.pointer;
 977
 978         /* There must be at least 4 elements = 3 elements + 1 package */
 979         if (!lpi_data || lpi_data->type != ACPI_TYPE_PACKAGE ||
 980             lpi_data->package.count < 4) {
 981                 pr_debug("not enough elements in _LPI\n");
 982                 ret = -ENODATA;
 983                 goto end;
 984         }
 985
 986         pkg_count = lpi_data->package.elements[2].integer.value;
 987
 988         /* Validate number of power states. */
 989         if (pkg_count < 1 || pkg_count != lpi_data->package.count - 3) {
 990                 pr_debug("count given by _LPI is not valid\n");
 991                 ret = -ENODATA;
 992                 goto end;
 993         }
 994
 995         lpi_state = kcalloc(pkg_count, sizeof(*lpi_state), GFP_KERNEL);
 996         if (!lpi_state) {
 997                 ret = -ENOMEM;
 998                 goto end;
 999         }
1000
1001         info->size = pkg_count;
1002         info->entries = lpi_state;
1003
1004         /* LPI States start at index 3 */
1005         for (loop = 3; state_idx <= pkg_count; loop++, state_idx++, lpi_state++) {
1006                 union acpi_object *element, *pkg_elem, *obj;
1007
1008                 element = &lpi_data->package.elements[loop];
1009                 if (element->type != ACPI_TYPE_PACKAGE || element->package.count < 7)
1010                         continue;
1011
1012                 pkg_elem = element->package.elements;
1013
1014                 obj = pkg_elem + 6;
1015                 if (obj->type == ACPI_TYPE_BUFFER) {
1016                         struct acpi_power_register *reg;
1017
1018                         reg = (struct acpi_power_register *)obj->buffer.pointer;
1019                         if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
1020                             reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE)
1021                                 continue;
1022
1023                         lpi_state->address = reg->address;
1024                         lpi_state->entry_method =
1025                                 reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE ?
1026                                 ACPI_CSTATE_FFH : ACPI_CSTATE_SYSTEMIO;
1027                 } else if (obj->type == ACPI_TYPE_INTEGER) {
1028                         lpi_state->entry_method = ACPI_CSTATE_INTEGER;
1029                         lpi_state->address = obj->integer.value;
1030                 } else {
1031                         continue;
1032                 }
1033
1034                 /* elements[7,8] skipped for now i.e. Residency/Usage counter*/
1035
1036                 obj = pkg_elem + 9;
1037                 if (obj->type == ACPI_TYPE_STRING)
1038                         strlcpy(lpi_state->desc, obj->string.pointer,
1039                                 ACPI_CX_DESC_LEN);
1040
1041                 lpi_state->index = state_idx;
1042                 if (obj_get_integer(pkg_elem + 0, &lpi_state->min_residency)) {
1043                         pr_debug("No min. residency found, assuming 10 us\n");
1044                         lpi_state->min_residency = 10;
1045                 }
1046
1047                 if (obj_get_integer(pkg_elem + 1, &lpi_state->wake_latency)) {
1048                         pr_debug("No wakeup residency found, assuming 10 us\n");
1049                         lpi_state->wake_latency = 10;
1050                 }
1051
1052                 if (obj_get_integer(pkg_elem + 2, &lpi_state->flags))
1053                         lpi_state->flags = 0;
1054
1055                 if (obj_get_integer(pkg_elem + 3, &lpi_state->arch_flags))
1056                         lpi_state->arch_flags = 0;
1057
1058                 if (obj_get_integer(pkg_elem + 4, &lpi_state->res_cnt_freq))
1059                         lpi_state->res_cnt_freq = 1;
1060
1061                 if (obj_get_integer(pkg_elem + 5, &lpi_state->enable_parent_state))
1062                         lpi_state->enable_parent_state = 0;
1063         }
1064
1065         acpi_handle_debug(handle, "Found %d power states\n", state_idx);
1066 end:
1067         kfree(buffer.pointer);
1068         return ret;
1069 }
1070
1071 /*
1072  * flat_state_cnt - the number of composite LPI states after the process of flattening
1073  */
1074 static int flat_state_cnt;
1075
1076 /**
1077  * combine_lpi_states - combine local and parent LPI states to form a composite LPI state
1078  *
1079  * @local: local LPI state
1080  * @parent: parent LPI state
1081  * @result: composite LPI state
1082  */
1083 static bool combine_lpi_states(struct acpi_lpi_state *local,
1084                                struct acpi_lpi_state *parent,
1085                                struct acpi_lpi_state *result)
1086 {
1087         if (parent->entry_method == ACPI_CSTATE_INTEGER) {
1088                 if (!parent->address) /* 0 means autopromotable */
1089                         return false;
1090                 result->address = local->address + parent->address;
1091         } else {
1092                 result->address = parent->address;
1093         }
1094
1095         result->min_residency = max(local->min_residency, parent->min_residency);
1096         result->wake_latency = local->wake_latency + parent->wake_latency;
1097         result->enable_parent_state = parent->enable_parent_state;
1098         result->entry_method = local->entry_method;
1099
1100         result->flags = parent->flags;
1101         result->arch_flags = parent->arch_flags;
1102         result->index = parent->index;
1103
1104         strlcpy(result->desc, local->desc, ACPI_CX_DESC_LEN);
1105         strlcat(result->desc, "+", ACPI_CX_DESC_LEN);
1106         strlcat(result->desc, parent->desc, ACPI_CX_DESC_LEN);
1107         return true;
1108 }
1109
1110 #define ACPI_LPI_STATE_FLAGS_ENABLED                    BIT(0)
1111
1112 static void stash_composite_state(struct acpi_lpi_states_array *curr_level,
1113                                   struct acpi_lpi_state *t)
1114 {
1115         curr_level->composite_states[curr_level->composite_states_size++] = t;
1116 }
1117
1118 static int flatten_lpi_states(struct acpi_processor *pr,
1119                               struct acpi_lpi_states_array *curr_level,
1120                               struct acpi_lpi_states_array *prev_level)
1121 {
1122         int i, j, state_count = curr_level->size;
1123         struct acpi_lpi_state *p, *t = curr_level->entries;
1124
1125         curr_level->composite_states_size = 0;
1126         for (j = 0; j < state_count; j++, t++) {
1127                 struct acpi_lpi_state *flpi;
1128
1129                 if (!(t->flags & ACPI_LPI_STATE_FLAGS_ENABLED))
1130                         continue;
1131
1132                 if (flat_state_cnt >= ACPI_PROCESSOR_MAX_POWER) {
1133                         pr_warn("Limiting number of LPI states to max (%d)\n",
1134                                 ACPI_PROCESSOR_MAX_POWER);
1135                         pr_warn("Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
1136                         break;
1137                 }
1138
1139                 flpi = &pr->power.lpi_states[flat_state_cnt];
1140
1141                 if (!prev_level) { /* leaf/processor node */
1142                         memcpy(flpi, t, sizeof(*t));
1143                         stash_composite_state(curr_level, flpi);
1144                         flat_state_cnt++;
1145                         continue;
1146                 }
1147
1148                 for (i = 0; i < prev_level->composite_states_size; i++) {
1149                         p = prev_level->composite_states[i];
1150                         if (t->index <= p->enable_parent_state &&
1151                             combine_lpi_states(p, t, flpi)) {
1152                                 stash_composite_state(curr_level, flpi);
1153                                 flat_state_cnt++;
1154                                 flpi++;
1155                         }
1156                 }
1157         }
1158
1159         kfree(curr_level->entries);
1160         return 0;
1161 }
1162
1163 static int acpi_processor_get_lpi_info(struct acpi_processor *pr)
1164 {
1165         int ret, i;
1166         acpi_status status;
1167         acpi_handle handle = pr->handle, pr_ahandle;
1168         struct acpi_device *d = NULL;
1169         struct acpi_lpi_states_array info[2], *tmp, *prev, *curr;
1170
1171         if (!osc_pc_lpi_support_confirmed)
1172                 return -EOPNOTSUPP;
1173
1174         if (!acpi_has_method(handle, "_LPI"))
1175                 return -EINVAL;
1176
1177         flat_state_cnt = 0;
1178         prev = &info[0];
1179         curr = &info[1];
1180         handle = pr->handle;
1181         ret = acpi_processor_evaluate_lpi(handle, prev);
1182         if (ret)
1183                 return ret;
1184         flatten_lpi_states(pr, prev, NULL);
1185
1186         status = acpi_get_parent(handle, &pr_ahandle);
1187         while (ACPI_SUCCESS(status)) {
1188                 acpi_bus_get_device(pr_ahandle, &d);
1189                 handle = pr_ahandle;
1190
1191                 if (strcmp(acpi_device_hid(d), ACPI_PROCESSOR_CONTAINER_HID))
1192                         break;
1193
1194                 /* can be optional ? */
1195                 if (!acpi_has_method(handle, "_LPI"))
1196                         break;
1197
1198                 ret = acpi_processor_evaluate_lpi(handle, curr);
1199                 if (ret)
1200                         break;
1201
1202                 /* flatten all the LPI states in this level of hierarchy */
1203                 flatten_lpi_states(pr, curr, prev);
1204
1205                 tmp = prev, prev = curr, curr = tmp;
1206
1207                 status = acpi_get_parent(handle, &pr_ahandle);
1208         }
1209
1210         pr->power.count = flat_state_cnt;
1211         /* reset the index after flattening */
1212         for (i = 0; i < pr->power.count; i++)
1213                 pr->power.lpi_states[i].index = i;
1214
1215         /* Tell driver that _LPI is supported. */
1216         pr->flags.has_lpi = 1;
1217         pr->flags.power = 1;
1218
1219         return 0;
1220 }
1221
1222 int __weak acpi_processor_ffh_lpi_probe(unsigned int cpu)
1223 {
1224         return -ENODEV;
1225 }
1226
1227 int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
1228 {
1229         return -ENODEV;
1230 }
1231
1232 /**
1233  * acpi_idle_lpi_enter - enters an ACPI any LPI state
1234  * @dev: the target CPU
1235  * @drv: cpuidle driver containing cpuidle state info
1236  * @index: index of target state
1237  *
1238  * Return: 0 for success or negative value for error
1239  */
1240 static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
1241                                struct cpuidle_driver *drv, int index)
1242 {
1243         struct acpi_processor *pr;
1244         struct acpi_lpi_state *lpi;
1245
1246         pr = __this_cpu_read(processors);
1247
1248         if (unlikely(!pr))
1249                 return -EINVAL;
1250
1251         lpi = &pr->power.lpi_states[index];
1252         if (lpi->entry_method == ACPI_CSTATE_FFH)
1253                 return acpi_processor_ffh_lpi_enter(lpi);
1254
1255         return -EINVAL;
1256 }
1257
1258 static int acpi_processor_setup_lpi_states(struct acpi_processor *pr)
1259 {
1260         int i;
1261         struct acpi_lpi_state *lpi;
1262         struct cpuidle_state *state;
1263         struct cpuidle_driver *drv = &acpi_idle_driver;
1264
1265         if (!pr->flags.has_lpi)
1266                 return -EOPNOTSUPP;
1267
1268         for (i = 0; i < pr->power.count && i < CPUIDLE_STATE_MAX; i++) {
1269                 lpi = &pr->power.lpi_states[i];
1270
1271                 state = &drv->states[i];
1272                 snprintf(state->name, CPUIDLE_NAME_LEN, "LPI-%d", i);
1273                 strlcpy(state->desc, lpi->desc, CPUIDLE_DESC_LEN);
1274                 state->exit_latency = lpi->wake_latency;
1275                 state->target_residency = lpi->min_residency;
1276                 if (lpi->arch_flags)
1277                         state->flags |= CPUIDLE_FLAG_TIMER_STOP;
1278                 state->enter = acpi_idle_lpi_enter;
1279                 drv->safe_state_index = i;
1280         }
1281
1282         drv->state_count = i;
1283
1284         return 0;
1285 }
1286
1287 /**
1288  * acpi_processor_setup_cpuidle_states- prepares and configures cpuidle
1289  * global state data i.e. idle routines
1290  *
1291  * @pr: the ACPI processor
1292  */
1293 static int acpi_processor_setup_cpuidle_states(struct acpi_processor *pr)
1294 {
1295         int i;
1296         struct cpuidle_driver *drv = &acpi_idle_driver;
1297
1298         if (!pr->flags.power_setup_done || !pr->flags.power)
1299                 return -EINVAL;
1300
1301         drv->safe_state_index = -1;
1302         for (i = ACPI_IDLE_STATE_START; i < CPUIDLE_STATE_MAX; i++) {
1303                 drv->states[i].name[0] = '\0';
1304                 drv->states[i].desc[0] = '\0';
1305         }
1306
1307         if (pr->flags.has_lpi)
1308                 return acpi_processor_setup_lpi_states(pr);
1309
1310         return acpi_processor_setup_cstates(pr);
1311 }
1312
1313 /**
1314  * acpi_processor_setup_cpuidle_dev - prepares and configures CPUIDLE
1315  * device i.e. per-cpu data
1316  *
1317  * @pr: the ACPI processor
1318  * @dev : the cpuidle device
1319  */
1320 static int acpi_processor_setup_cpuidle_dev(struct acpi_processor *pr,
1321                                             struct cpuidle_device *dev)
1322 {
1323         if (!pr->flags.power_setup_done || !pr->flags.power || !dev)
1324                 return -EINVAL;
1325
1326         dev->cpu = pr->id;
1327         if (pr->flags.has_lpi)
1328                 return acpi_processor_ffh_lpi_probe(pr->id);
1329
1330         return acpi_processor_setup_cpuidle_cx(pr, dev);
1331 }
1332
1333 static int acpi_processor_get_power_info(struct acpi_processor *pr)
1334 {
1335         int ret;
1336
1337         ret = acpi_processor_get_lpi_info(pr);
1338         if (ret)
1339                 ret = acpi_processor_get_cstate_info(pr);
1340
1341         return ret;
1342 }
1343
1344 int acpi_processor_hotplug(struct acpi_processor *pr)
1345 {
1346         int ret = 0;
1347         struct cpuidle_device *dev;
1348
1349         if (disabled_by_idle_boot_param())
1350                 return 0;
1351
1352         if (!pr->flags.power_setup_done)
1353                 return -ENODEV;
1354
1355         dev = per_cpu(acpi_cpuidle_device, pr->id);
1356         cpuidle_pause_and_lock();
1357         cpuidle_disable_device(dev);
1358         ret = acpi_processor_get_power_info(pr);
1359         if (!ret && pr->flags.power) {
1360                 acpi_processor_setup_cpuidle_dev(pr, dev);
1361                 ret = cpuidle_enable_device(dev);
1362         }
1363         cpuidle_resume_and_unlock();
1364
1365         return ret;
1366 }
1367
1368 int acpi_processor_power_state_has_changed(struct acpi_processor *pr)
1369 {
1370         int cpu;
1371         struct acpi_processor *_pr;
1372         struct cpuidle_device *dev;
1373
1374         if (disabled_by_idle_boot_param())
1375                 return 0;
1376
1377         if (!pr->flags.power_setup_done)
1378                 return -ENODEV;
1379
1380         /*
1381          * FIXME:  Design the ACPI notification to make it once per
1382          * system instead of once per-cpu.  This condition is a hack
1383          * to make the code that updates C-States be called once.
1384          */
1385
1386         if (pr->id == 0 && cpuidle_get_driver() == &acpi_idle_driver) {
1387
1388                 /* Protect against cpu-hotplug */
1389                 get_online_cpus();
1390                 cpuidle_pause_and_lock();
1391
1392                 /* Disable all cpuidle devices */
1393                 for_each_online_cpu(cpu) {
1394                         _pr = per_cpu(processors, cpu);
1395                         if (!_pr || !_pr->flags.power_setup_done)
1396                                 continue;
1397                         dev = per_cpu(acpi_cpuidle_device, cpu);
1398                         cpuidle_disable_device(dev);
1399                 }
1400
1401                 /* Populate Updated C-state information */
1402                 acpi_processor_get_power_info(pr);
1403                 acpi_processor_setup_cpuidle_states(pr);
1404
1405                 /* Enable all cpuidle devices */
1406                 for_each_online_cpu(cpu) {
1407                         _pr = per_cpu(processors, cpu);
1408                         if (!_pr || !_pr->flags.power_setup_done)
1409                                 continue;
1410                         acpi_processor_get_power_info(_pr);
1411                         if (_pr->flags.power) {
1412                                 dev = per_cpu(acpi_cpuidle_device, cpu);
1413                                 acpi_processor_setup_cpuidle_dev(_pr, dev);
1414                                 cpuidle_enable_device(dev);
1415                         }
1416                 }
1417                 cpuidle_resume_and_unlock();
1418                 put_online_cpus();
1419         }
1420
1421         return 0;
1422 }
1423
1424 static int acpi_processor_registered;
1425
1426 int acpi_processor_power_init(struct acpi_processor *pr)
1427 {
1428         int retval;
1429         struct cpuidle_device *dev;
1430
1431         if (disabled_by_idle_boot_param())
1432                 return 0;
1433
1434         acpi_processor_cstate_first_run_checks();
1435
1436         if (!acpi_processor_get_power_info(pr))
1437                 pr->flags.power_setup_done = 1;
1438
1439         /*
1440          * Install the idle handler if processor power management is supported.
1441          * Note that we use previously set idle handler will be used on
1442          * platforms that only support C1.
1443          */
1444         if (pr->flags.power) {
1445                 /* Register acpi_idle_driver if not already registered */
1446                 if (!acpi_processor_registered) {
1447                         acpi_processor_setup_cpuidle_states(pr);
1448                         retval = cpuidle_register_driver(&acpi_idle_driver);
1449                         if (retval)
1450                                 return retval;
1451                         pr_debug("%s registered with cpuidle\n",
1452                                  acpi_idle_driver.name);
1453                 }
1454
1455                 dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1456                 if (!dev)
1457                         return -ENOMEM;
1458                 per_cpu(acpi_cpuidle_device, pr->id) = dev;
1459
1460                 acpi_processor_setup_cpuidle_dev(pr, dev);
1461
1462                 /* Register per-cpu cpuidle_device. Cpuidle driver
1463                  * must already be registered before registering device
1464                  */
1465                 retval = cpuidle_register_device(dev);
1466                 if (retval) {
1467                         if (acpi_processor_registered == 0)
1468                                 cpuidle_unregister_driver(&acpi_idle_driver);
1469                         return retval;
1470                 }
1471                 acpi_processor_registered++;
1472         }
1473         return 0;
1474 }
1475
1476 int acpi_processor_power_exit(struct acpi_processor *pr)
1477 {
1478         struct cpuidle_device *dev = per_cpu(acpi_cpuidle_device, pr->id);
1479
1480         if (disabled_by_idle_boot_param())
1481                 return 0;
1482
1483         if (pr->flags.power) {
1484                 cpuidle_unregister_device(dev);
1485                 acpi_processor_registered--;
1486                 if (acpi_processor_registered == 0)
1487                         cpuidle_unregister_driver(&acpi_idle_driver);
1488         }
1489
1490         pr->flags.power_setup_done = 0;
1491         return 0;
1492 }