drivers/acpi/processor_idle.c

   1 /*
   2  * processor_idle - idle state submodule to the ACPI processor driver
   3  *
   4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
   5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
   6  *  Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
   7  *  Copyright (C) 2004  Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
   8  *                      - Added processor hotplug support
   9  *  Copyright (C) 2005  Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
  10  *                      - Added support for C3 on SMP
  11  *
  12  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  13  *
  14  *  This program is free software; you can redistribute it and/or modify
  15  *  it under the terms of the GNU General Public License as published by
  16  *  the Free Software Foundation; either version 2 of the License, or (at
  17  *  your option) any later version.
  18  *
  19  *  This program is distributed in the hope that it will be useful, but
  20  *  WITHOUT ANY WARRANTY; without even the implied warranty of
  21  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  22  *  General Public License for more details.
  23  *
  24  *  You should have received a copy of the GNU General Public License along
  25  *  with this program; if not, write to the Free Software Foundation, Inc.,
  26  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
  27  *
  28  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  29  */
  30
  31 #include <linux/kernel.h>
  32 #include <linux/module.h>
  33 #include <linux/init.h>
  34 #include <linux/cpufreq.h>
  35 #include <linux/slab.h>
  36 #include <linux/proc_fs.h>
  37 #include <linux/seq_file.h>
  38 #include <linux/acpi.h>
  39 #include <linux/dmi.h>
  40 #include <linux/moduleparam.h>
  41 #include <linux/sched.h>        /* need_resched() */
  42 #include <linux/pm_qos_params.h>
  43 #include <linux/clockchips.h>
  44 #include <linux/cpuidle.h>
  45 #include <linux/irqflags.h>
  46
  47 /*
  48  * Include the apic definitions for x86 to have the APIC timer related defines
  49  * available also for UP (on SMP it gets magically included via linux/smp.h).
  50  * asm/acpi.h is not an option, as it would require more include magic. Also
  51  * creating an empty asm-ia64/apic.h would just trade pest vs. cholera.
  52  */
  53 #ifdef CONFIG_X86
  54 #include <asm/apic.h>
  55 #endif
  56
  57 #include <asm/io.h>
  58 #include <asm/uaccess.h>
  59
  60 #include <acpi/acpi_bus.h>
  61 #include <acpi/processor.h>
  62 #include <asm/processor.h>
  63
  64 #define PREFIX "ACPI: "
  65
  66 #define ACPI_PROCESSOR_CLASS            "processor"
  67 #define _COMPONENT              ACPI_PROCESSOR_COMPONENT
  68 ACPI_MODULE_NAME("processor_idle");
  69 #define ACPI_PROCESSOR_FILE_POWER       "power"
  70 #define PM_TIMER_TICK_NS                (1000000000ULL/PM_TIMER_FREQUENCY)
  71 #define C2_OVERHEAD                     1       /* 1us */
  72 #define C3_OVERHEAD                     1       /* 1us */
  73 #define PM_TIMER_TICKS_TO_US(p)         (((p) * 1000)/(PM_TIMER_FREQUENCY/1000))
  74
  75 static unsigned int max_cstate __read_mostly = ACPI_PROCESSOR_MAX_POWER;
  76 module_param(max_cstate, uint, 0000);
  77 static unsigned int nocst __read_mostly;
  78 module_param(nocst, uint, 0000);
  79 static int bm_check_disable __read_mostly;
  80 module_param(bm_check_disable, uint, 0000);
  81
  82 static unsigned int latency_factor __read_mostly = 2;
  83 module_param(latency_factor, uint, 0644);
  84
  85 #ifdef CONFIG_ACPI_PROCFS
  86 static u64 us_to_pm_timer_ticks(s64 t)
  87 {
  88         return div64_u64(t * PM_TIMER_FREQUENCY, 1000000);
  89 }
  90 #endif
  91
  92 /*
  93  * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
  94  * For now disable this. Probably a bug somewhere else.
  95  *
  96  * To skip this limit, boot/load with a large max_cstate limit.
  97  */
  98 static int set_max_cstate(const struct dmi_system_id *id)
  99 {
 100         if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
 101                 return 0;
 102
 103         printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
 104                " Override with \"processor.max_cstate=%d\"\n", id->ident,
 105                (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
 106
 107         max_cstate = (long)id->driver_data;
 108
 109         return 0;
 110 }
 111
 112 /* Actually this shouldn't be __cpuinitdata, would be better to fix the
 113    callers to only run once -AK */
 114 static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
 115         { set_max_cstate, "Clevo 5600D", {
 116           DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
 117           DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
 118          (void *)2},
 119         { set_max_cstate, "Pavilion zv5000", {
 120           DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
 121           DMI_MATCH(DMI_PRODUCT_NAME,"Pavilion zv5000 (DS502A#ABA)")},
 122          (void *)1},
 123         { set_max_cstate, "Asus L8400B", {
 124           DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
 125           DMI_MATCH(DMI_PRODUCT_NAME,"L8400B series Notebook PC")},
 126          (void *)1},
 127         {},
 128 };
 129
 130
 131 /*
 132  * Callers should disable interrupts before the call and enable
 133  * interrupts after return.
 134  */
 135 static void acpi_safe_halt(void)
 136 {
 137         current_thread_info()->status &= ~TS_POLLING;
 138         /*
 139          * TS_POLLING-cleared state must be visible before we
 140          * test NEED_RESCHED:
 141          */
 142         smp_mb();
 143         if (!need_resched()) {
 144                 safe_halt();
 145                 local_irq_disable();
 146         }
 147         current_thread_info()->status |= TS_POLLING;
 148 }
 149
 150 #ifdef ARCH_APICTIMER_STOPS_ON_C3
 151
 152 /*
 153  * Some BIOS implementations switch to C3 in the published C2 state.
 154  * This seems to be a common problem on AMD boxen, but other vendors
 155  * are affected too. We pick the most conservative approach: we assume
 156  * that the local APIC stops in both C2 and C3.
 157  */
 158 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 159                                    struct acpi_processor_cx *cx)
 160 {
 161         struct acpi_processor_power *pwr = &pr->power;
 162         u8 type = local_apic_timer_c2_ok ? ACPI_STATE_C3 : ACPI_STATE_C2;
 163
 164         if (cpu_has(&cpu_data(pr->id), X86_FEATURE_ARAT))
 165                 return;
 166
 167         if (c1e_detected)
 168                 type = ACPI_STATE_C1;
 169
 170         /*
 171          * Check, if one of the previous states already marked the lapic
 172          * unstable
 173          */
 174         if (pwr->timer_broadcast_on_state < state)
 175                 return;
 176
 177         if (cx->type >= type)
 178                 pr->power.timer_broadcast_on_state = state;
 179 }
 180
 181 static void __lapic_timer_propagate_broadcast(void *arg)
 182 {
 183         struct acpi_processor *pr = (struct acpi_processor *) arg;
 184         unsigned long reason;
 185
 186         reason = pr->power.timer_broadcast_on_state < INT_MAX ?
 187                 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
 188
 189         clockevents_notify(reason, &pr->id);
 190 }
 191
 192 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr)
 193 {
 194         smp_call_function_single(pr->id, __lapic_timer_propagate_broadcast,
 195                                  (void *)pr, 1);
 196 }
 197
 198 /* Power(C) State timer broadcast control */
 199 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 200                                        struct acpi_processor_cx *cx,
 201                                        int broadcast)
 202 {
 203         int state = cx - pr->power.states;
 204
 205         if (state >= pr->power.timer_broadcast_on_state) {
 206                 unsigned long reason;
 207
 208                 reason = broadcast ?  CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
 209                         CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
 210                 clockevents_notify(reason, &pr->id);
 211         }
 212 }
 213
 214 #else
 215
 216 static void lapic_timer_check_state(int state, struct acpi_processor *pr,
 217                                    struct acpi_processor_cx *cstate) { }
 218 static void lapic_timer_propagate_broadcast(struct acpi_processor *pr) { }
 219 static void lapic_timer_state_broadcast(struct acpi_processor *pr,
 220                                        struct acpi_processor_cx *cx,
 221                                        int broadcast)
 222 {
 223 }
 224
 225 #endif
 226
 227 /*
 228  * Suspend / resume control
 229  */
 230 static int acpi_idle_suspend;
 231 static u32 saved_bm_rld;
 232
 233 static void acpi_idle_bm_rld_save(void)
 234 {
 235         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &saved_bm_rld);
 236 }
 237 static void acpi_idle_bm_rld_restore(void)
 238 {
 239         u32 resumed_bm_rld;
 240
 241         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_RLD, &resumed_bm_rld);
 242
 243         if (resumed_bm_rld != saved_bm_rld)
 244                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, saved_bm_rld);
 245 }
 246
 247 int acpi_processor_suspend(struct acpi_device * device, pm_message_t state)
 248 {
 249         if (acpi_idle_suspend == 1)
 250                 return 0;
 251
 252         acpi_idle_bm_rld_save();
 253         acpi_idle_suspend = 1;
 254         return 0;
 255 }
 256
 257 int acpi_processor_resume(struct acpi_device * device)
 258 {
 259         if (acpi_idle_suspend == 0)
 260                 return 0;
 261
 262         acpi_idle_bm_rld_restore();
 263         acpi_idle_suspend = 0;
 264         return 0;
 265 }
 266
 267 #if defined(CONFIG_X86)
 268 static void tsc_check_state(int state)
 269 {
 270         switch (boot_cpu_data.x86_vendor) {
 271         case X86_VENDOR_AMD:
 272         case X86_VENDOR_INTEL:
 273                 /*
 274                  * AMD Fam10h TSC will tick in all
 275                  * C/P/S0/S1 states when this bit is set.
 276                  */
 277                 if (boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
 278                         return;
 279
 280                 /*FALL THROUGH*/
 281         default:
 282                 /* TSC could halt in idle, so notify users */
 283                 if (state > ACPI_STATE_C1)
 284                         mark_tsc_unstable("TSC halts in idle");
 285         }
 286 }
 287 #else
 288 static void tsc_check_state(int state) { return; }
 289 #endif
 290
 291 static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
 292 {
 293
 294         if (!pr)
 295                 return -EINVAL;
 296
 297         if (!pr->pblk)
 298                 return -ENODEV;
 299
 300         /* if info is obtained from pblk/fadt, type equals state */
 301         pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
 302         pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
 303
 304 #ifndef CONFIG_HOTPLUG_CPU
 305         /*
 306          * Check for P_LVL2_UP flag before entering C2 and above on
 307          * an SMP system.
 308          */
 309         if ((num_online_cpus() > 1) &&
 310             !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
 311                 return -ENODEV;
 312 #endif
 313
 314         /* determine C2 and C3 address from pblk */
 315         pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
 316         pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
 317
 318         /* determine latencies from FADT */
 319         pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
 320         pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
 321
 322         /*
 323          * FADT specified C2 latency must be less than or equal to
 324          * 100 microseconds.
 325          */
 326         if (acpi_gbl_FADT.C2latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
 327                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 328                         "C2 latency too large [%d]\n", acpi_gbl_FADT.C2latency));
 329                 /* invalidate C2 */
 330                 pr->power.states[ACPI_STATE_C2].address = 0;
 331         }
 332
 333         /*
 334          * FADT supplied C3 latency must be less than or equal to
 335          * 1000 microseconds.
 336          */
 337         if (acpi_gbl_FADT.C3latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
 338                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 339                         "C3 latency too large [%d]\n", acpi_gbl_FADT.C3latency));
 340                 /* invalidate C3 */
 341                 pr->power.states[ACPI_STATE_C3].address = 0;
 342         }
 343
 344         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 345                           "lvl2[0x%08x] lvl3[0x%08x]\n",
 346                           pr->power.states[ACPI_STATE_C2].address,
 347                           pr->power.states[ACPI_STATE_C3].address));
 348
 349         return 0;
 350 }
 351
 352 static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
 353 {
 354         if (!pr->power.states[ACPI_STATE_C1].valid) {
 355                 /* set the first C-State to C1 */
 356                 /* all processors need to support C1 */
 357                 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
 358                 pr->power.states[ACPI_STATE_C1].valid = 1;
 359                 pr->power.states[ACPI_STATE_C1].entry_method = ACPI_CSTATE_HALT;
 360         }
 361         /* the C0 state only exists as a filler in our array */
 362         pr->power.states[ACPI_STATE_C0].valid = 1;
 363         return 0;
 364 }
 365
 366 static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
 367 {
 368         acpi_status status = 0;
 369         u64 count;
 370         int current_count;
 371         int i;
 372         struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
 373         union acpi_object *cst;
 374
 375
 376         if (nocst)
 377                 return -ENODEV;
 378
 379         current_count = 0;
 380
 381         status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
 382         if (ACPI_FAILURE(status)) {
 383                 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
 384                 return -ENODEV;
 385         }
 386
 387         cst = buffer.pointer;
 388
 389         /* There must be at least 2 elements */
 390         if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
 391                 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
 392                 status = -EFAULT;
 393                 goto end;
 394         }
 395
 396         count = cst->package.elements[0].integer.value;
 397
 398         /* Validate number of power states. */
 399         if (count < 1 || count != cst->package.count - 1) {
 400                 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
 401                 status = -EFAULT;
 402                 goto end;
 403         }
 404
 405         /* Tell driver that at least _CST is supported. */
 406         pr->flags.has_cst = 1;
 407
 408         for (i = 1; i <= count; i++) {
 409                 union acpi_object *element;
 410                 union acpi_object *obj;
 411                 struct acpi_power_register *reg;
 412                 struct acpi_processor_cx cx;
 413
 414                 memset(&cx, 0, sizeof(cx));
 415
 416                 element = &(cst->package.elements[i]);
 417                 if (element->type != ACPI_TYPE_PACKAGE)
 418                         continue;
 419
 420                 if (element->package.count != 4)
 421                         continue;
 422
 423                 obj = &(element->package.elements[0]);
 424
 425                 if (obj->type != ACPI_TYPE_BUFFER)
 426                         continue;
 427
 428                 reg = (struct acpi_power_register *)obj->buffer.pointer;
 429
 430                 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
 431                     (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
 432                         continue;
 433
 434                 /* There should be an easy way to extract an integer... */
 435                 obj = &(element->package.elements[1]);
 436                 if (obj->type != ACPI_TYPE_INTEGER)
 437                         continue;
 438
 439                 cx.type = obj->integer.value;
 440                 /*
 441                  * Some buggy BIOSes won't list C1 in _CST -
 442                  * Let acpi_processor_get_power_info_default() handle them later
 443                  */
 444                 if (i == 1 && cx.type != ACPI_STATE_C1)
 445                         current_count++;
 446
 447                 cx.address = reg->address;
 448                 cx.index = current_count + 1;
 449
 450                 cx.entry_method = ACPI_CSTATE_SYSTEMIO;
 451                 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
 452                         if (acpi_processor_ffh_cstate_probe
 453                                         (pr->id, &cx, reg) == 0) {
 454                                 cx.entry_method = ACPI_CSTATE_FFH;
 455                         } else if (cx.type == ACPI_STATE_C1) {
 456                                 /*
 457                                  * C1 is a special case where FIXED_HARDWARE
 458                                  * can be handled in non-MWAIT way as well.
 459                                  * In that case, save this _CST entry info.
 460                                  * Otherwise, ignore this info and continue.
 461                                  */
 462                                 cx.entry_method = ACPI_CSTATE_HALT;
 463                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 464                         } else {
 465                                 continue;
 466                         }
 467                         if (cx.type == ACPI_STATE_C1 &&
 468                                         (idle_halt || idle_nomwait)) {
 469                                 /*
 470                                  * In most cases the C1 space_id obtained from
 471                                  * _CST object is FIXED_HARDWARE access mode.
 472                                  * But when the option of idle=halt is added,
 473                                  * the entry_method type should be changed from
 474                                  * CSTATE_FFH to CSTATE_HALT.
 475                                  * When the option of idle=nomwait is added,
 476                                  * the C1 entry_method type should be
 477                                  * CSTATE_HALT.
 478                                  */
 479                                 cx.entry_method = ACPI_CSTATE_HALT;
 480                                 snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI HLT");
 481                         }
 482                 } else {
 483                         snprintf(cx.desc, ACPI_CX_DESC_LEN, "ACPI IOPORT 0x%x",
 484                                  cx.address);
 485                 }
 486
 487                 if (cx.type == ACPI_STATE_C1) {
 488                         cx.valid = 1;
 489                 }
 490
 491                 obj = &(element->package.elements[2]);
 492                 if (obj->type != ACPI_TYPE_INTEGER)
 493                         continue;
 494
 495                 cx.latency = obj->integer.value;
 496
 497                 obj = &(element->package.elements[3]);
 498                 if (obj->type != ACPI_TYPE_INTEGER)
 499                         continue;
 500
 501                 cx.power = obj->integer.value;
 502
 503                 current_count++;
 504                 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
 505
 506                 /*
 507                  * We support total ACPI_PROCESSOR_MAX_POWER - 1
 508                  * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
 509                  */
 510                 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
 511                         printk(KERN_WARNING
 512                                "Limiting number of power states to max (%d)\n",
 513                                ACPI_PROCESSOR_MAX_POWER);
 514                         printk(KERN_WARNING
 515                                "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
 516                         break;
 517                 }
 518         }
 519
 520         ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
 521                           current_count));
 522
 523         /* Validate number of power states discovered */
 524         if (current_count < 2)
 525                 status = -EFAULT;
 526
 527       end:
 528         kfree(buffer.pointer);
 529
 530         return status;
 531 }
 532
 533 static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
 534                                            struct acpi_processor_cx *cx)
 535 {
 536         static int bm_check_flag = -1;
 537         static int bm_control_flag = -1;
 538
 539
 540         if (!cx->address)
 541                 return;
 542
 543         /*
 544          * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
 545          * DMA transfers are used by any ISA device to avoid livelock.
 546          * Note that we could disable Type-F DMA (as recommended by
 547          * the erratum), but this is known to disrupt certain ISA
 548          * devices thus we take the conservative approach.
 549          */
 550         else if (errata.piix4.fdma) {
 551                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 552                                   "C3 not supported on PIIX4 with Type-F DMA\n"));
 553                 return;
 554         }
 555
 556         /* All the logic here assumes flags.bm_check is same across all CPUs */
 557         if (bm_check_flag == -1) {
 558                 /* Determine whether bm_check is needed based on CPU  */
 559                 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
 560                 bm_check_flag = pr->flags.bm_check;
 561                 bm_control_flag = pr->flags.bm_control;
 562         } else {
 563                 pr->flags.bm_check = bm_check_flag;
 564                 pr->flags.bm_control = bm_control_flag;
 565         }
 566
 567         if (pr->flags.bm_check) {
 568                 if (!pr->flags.bm_control) {
 569                         if (pr->flags.has_cst != 1) {
 570                                 /* bus mastering control is necessary */
 571                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 572                                         "C3 support requires BM control\n"));
 573                                 return;
 574                         } else {
 575                                 /* Here we enter C3 without bus mastering */
 576                                 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 577                                         "C3 support without BM control\n"));
 578                         }
 579                 }
 580         } else {
 581                 /*
 582                  * WBINVD should be set in fadt, for C3 state to be
 583                  * supported on when bm_check is not required.
 584                  */
 585                 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
 586                         ACPI_DEBUG_PRINT((ACPI_DB_INFO,
 587                                           "Cache invalidation should work properly"
 588                                           " for C3 to be enabled on SMP systems\n"));
 589                         return;
 590                 }
 591         }
 592
 593         /*
 594          * Otherwise we've met all of our C3 requirements.
 595          * Normalize the C3 latency to expidite policy.  Enable
 596          * checking of bus mastering status (bm_check) so we can
 597          * use this in our C3 policy
 598          */
 599         cx->valid = 1;
 600
 601         cx->latency_ticks = cx->latency;
 602         /*
 603          * On older chipsets, BM_RLD needs to be set
 604          * in order for Bus Master activity to wake the
 605          * system from C3.  Newer chipsets handle DMA
 606          * during C3 automatically and BM_RLD is a NOP.
 607          * In either case, the proper way to
 608          * handle BM_RLD is to set it and leave it set.
 609          */
 610         acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
 611
 612         return;
 613 }
 614
 615 static int acpi_processor_power_verify(struct acpi_processor *pr)
 616 {
 617         unsigned int i;
 618         unsigned int working = 0;
 619
 620         pr->power.timer_broadcast_on_state = INT_MAX;
 621
 622         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
 623                 struct acpi_processor_cx *cx = &pr->power.states[i];
 624
 625                 switch (cx->type) {
 626                 case ACPI_STATE_C1:
 627                         cx->valid = 1;
 628                         break;
 629
 630                 case ACPI_STATE_C2:
 631                         if (!cx->address)
 632                                 break;
 633                         cx->valid = 1;
 634                         cx->latency_ticks = cx->latency; /* Normalize latency */
 635                         break;
 636
 637                 case ACPI_STATE_C3:
 638                         acpi_processor_power_verify_c3(pr, cx);
 639                         break;
 640                 }
 641                 if (!cx->valid)
 642                         continue;
 643
 644                 lapic_timer_check_state(i, pr, cx);
 645                 tsc_check_state(cx->type);
 646                 working++;
 647         }
 648
 649         lapic_timer_propagate_broadcast(pr);
 650
 651         return (working);
 652 }
 653
 654 static int acpi_processor_get_power_info(struct acpi_processor *pr)
 655 {
 656         unsigned int i;
 657         int result;
 658
 659
 660         /* NOTE: the idle thread may not be running while calling
 661          * this function */
 662
 663         /* Zero initialize all the C-states info. */
 664         memset(pr->power.states, 0, sizeof(pr->power.states));
 665
 666         result = acpi_processor_get_power_info_cst(pr);
 667         if (result == -ENODEV)
 668                 result = acpi_processor_get_power_info_fadt(pr);
 669
 670         if (result)
 671                 return result;
 672
 673         acpi_processor_get_power_info_default(pr);
 674
 675         pr->power.count = acpi_processor_power_verify(pr);
 676
 677         /*
 678          * if one state of type C2 or C3 is available, mark this
 679          * CPU as being "idle manageable"
 680          */
 681         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
 682                 if (pr->power.states[i].valid) {
 683                         pr->power.count = i;
 684                         if (pr->power.states[i].type >= ACPI_STATE_C2)
 685                                 pr->flags.power = 1;
 686                 }
 687         }
 688
 689         return 0;
 690 }
 691
 692 #ifdef CONFIG_ACPI_PROCFS
 693 static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
 694 {
 695         struct acpi_processor *pr = seq->private;
 696         unsigned int i;
 697
 698
 699         if (!pr)
 700                 goto end;
 701
 702         seq_printf(seq, "active state:            C%zd\n"
 703                    "max_cstate:              C%d\n"
 704                    "maximum allowed latency: %d usec\n",
 705                    pr->power.state ? pr->power.state - pr->power.states : 0,
 706                    max_cstate, pm_qos_request(PM_QOS_CPU_DMA_LATENCY));
 707
 708         seq_puts(seq, "states:\n");
 709
 710         for (i = 1; i <= pr->power.count; i++) {
 711                 seq_printf(seq, "   %cC%d:                  ",
 712                            (&pr->power.states[i] ==
 713                             pr->power.state ? '*' : ' '), i);
 714
 715                 if (!pr->power.states[i].valid) {
 716                         seq_puts(seq, "<not supported>\n");
 717                         continue;
 718                 }
 719
 720                 switch (pr->power.states[i].type) {
 721                 case ACPI_STATE_C1:
 722                         seq_printf(seq, "type[C1] ");
 723                         break;
 724                 case ACPI_STATE_C2:
 725                         seq_printf(seq, "type[C2] ");
 726                         break;
 727                 case ACPI_STATE_C3:
 728                         seq_printf(seq, "type[C3] ");
 729                         break;
 730                 default:
 731                         seq_printf(seq, "type[--] ");
 732                         break;
 733                 }
 734
 735                 seq_puts(seq, "promotion[--] ");
 736
 737                 seq_puts(seq, "demotion[--] ");
 738
 739                 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020Lu]\n",
 740                            pr->power.states[i].latency,
 741                            pr->power.states[i].usage,
 742                            us_to_pm_timer_ticks(pr->power.states[i].time));
 743         }
 744
 745       end:
 746         return 0;
 747 }
 748
 749 static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
 750 {
 751         return single_open(file, acpi_processor_power_seq_show,
 752                            PDE(inode)->data);
 753 }
 754
 755 static const struct file_operations acpi_processor_power_fops = {
 756         .owner = THIS_MODULE,
 757         .open = acpi_processor_power_open_fs,
 758         .read = seq_read,
 759         .llseek = seq_lseek,
 760         .release = single_release,
 761 };
 762 #endif
 763
 764 /**
 765  * acpi_idle_bm_check - checks if bus master activity was detected
 766  */
 767 static int acpi_idle_bm_check(void)
 768 {
 769         u32 bm_status = 0;
 770
 771         if (bm_check_disable)
 772                 return 0;
 773
 774         acpi_read_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
 775         if (bm_status)
 776                 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
 777         /*
 778          * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
 779          * the true state of bus mastering activity; forcing us to
 780          * manually check the BMIDEA bit of each IDE channel.
 781          */
 782         else if (errata.piix4.bmisx) {
 783                 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
 784                     || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
 785                         bm_status = 1;
 786         }
 787         return bm_status;
 788 }
 789
 790 /**
 791  * acpi_idle_do_entry - a helper function that does C2 and C3 type entry
 792  * @cx: cstate data
 793  *
 794  * Caller disables interrupt before call and enables interrupt after return.
 795  */
 796 static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 797 {
 798         /* Don't trace irqs off for idle */
 799         stop_critical_timings();
 800         if (cx->entry_method == ACPI_CSTATE_FFH) {
 801                 /* Call into architectural FFH based C-state */
 802                 acpi_processor_ffh_cstate_enter(cx);
 803         } else if (cx->entry_method == ACPI_CSTATE_HALT) {
 804                 acpi_safe_halt();
 805         } else {
 806                 int unused;
 807                 /* IO port based C-state */
 808                 inb(cx->address);
 809                 /* Dummy wait op - must do something useless after P_LVL2 read
 810                    because chipsets cannot guarantee that STPCLK# signal
 811                    gets asserted in time to freeze execution properly. */
 812                 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
 813         }
 814         start_critical_timings();
 815 }
 816
 817 /**
 818  * acpi_idle_enter_c1 - enters an ACPI C1 state-type
 819  * @dev: the target CPU
 820  * @state: the state data
 821  *
 822  * This is equivalent to the HALT instruction.
 823  */
 824 static int acpi_idle_enter_c1(struct cpuidle_device *dev,
 825                               struct cpuidle_state *state)
 826 {
 827         ktime_t  kt1, kt2;
 828         s64 idle_time;
 829         struct acpi_processor *pr;
 830         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 831
 832         pr = __get_cpu_var(processors);
 833
 834         if (unlikely(!pr))
 835                 return 0;
 836
 837         local_irq_disable();
 838
 839         /* Do not access any ACPI IO ports in suspend path */
 840         if (acpi_idle_suspend) {
 841                 local_irq_enable();
 842                 cpu_relax();
 843                 return 0;
 844         }
 845
 846         lapic_timer_state_broadcast(pr, cx, 1);
 847         kt1 = ktime_get_real();
 848         acpi_idle_do_entry(cx);
 849         kt2 = ktime_get_real();
 850         idle_time =  ktime_to_us(ktime_sub(kt2, kt1));
 851
 852         local_irq_enable();
 853         cx->usage++;
 854         lapic_timer_state_broadcast(pr, cx, 0);
 855
 856         return idle_time;
 857 }
 858
 859 /**
 860  * acpi_idle_enter_simple - enters an ACPI state without BM handling
 861  * @dev: the target CPU
 862  * @state: the state data
 863  */
 864 static int acpi_idle_enter_simple(struct cpuidle_device *dev,
 865                                   struct cpuidle_state *state)
 866 {
 867         struct acpi_processor *pr;
 868         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 869         ktime_t  kt1, kt2;
 870         s64 idle_time_ns;
 871         s64 idle_time;
 872
 873         pr = __get_cpu_var(processors);
 874
 875         if (unlikely(!pr))
 876                 return 0;
 877
 878         if (acpi_idle_suspend)
 879                 return(acpi_idle_enter_c1(dev, state));
 880
 881         local_irq_disable();
 882
 883         if (cx->entry_method != ACPI_CSTATE_FFH) {
 884                 current_thread_info()->status &= ~TS_POLLING;
 885                 /*
 886                  * TS_POLLING-cleared state must be visible before we test
 887                  * NEED_RESCHED:
 888                  */
 889                 smp_mb();
 890
 891                 if (unlikely(need_resched())) {
 892                         current_thread_info()->status |= TS_POLLING;
 893                         local_irq_enable();
 894                         return 0;
 895                 }
 896         }
 897
 898         /*
 899          * Must be done before busmaster disable as we might need to
 900          * access HPET !
 901          */
 902         lapic_timer_state_broadcast(pr, cx, 1);
 903
 904         if (cx->type == ACPI_STATE_C3)
 905                 ACPI_FLUSH_CPU_CACHE();
 906
 907         kt1 = ktime_get_real();
 908         /* Tell the scheduler that we are going deep-idle: */
 909         sched_clock_idle_sleep_event();
 910         acpi_idle_do_entry(cx);
 911         kt2 = ktime_get_real();
 912         idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1));
 913         idle_time = idle_time_ns;
 914         do_div(idle_time, NSEC_PER_USEC);
 915
 916         /* Tell the scheduler how much we idled: */
 917         sched_clock_idle_wakeup_event(idle_time_ns);
 918
 919         local_irq_enable();
 920         if (cx->entry_method != ACPI_CSTATE_FFH)
 921                 current_thread_info()->status |= TS_POLLING;
 922
 923         cx->usage++;
 924
 925         lapic_timer_state_broadcast(pr, cx, 0);
 926         cx->time += idle_time;
 927         return idle_time;
 928 }
 929
 930 static int c3_cpu_count;
 931 static DEFINE_SPINLOCK(c3_lock);
 932
 933 /**
 934  * acpi_idle_enter_bm - enters C3 with proper BM handling
 935  * @dev: the target CPU
 936  * @state: the state data
 937  *
 938  * If BM is detected, the deepest non-C3 idle state is entered instead.
 939  */
 940 static int acpi_idle_enter_bm(struct cpuidle_device *dev,
 941                               struct cpuidle_state *state)
 942 {
 943         struct acpi_processor *pr;
 944         struct acpi_processor_cx *cx = cpuidle_get_statedata(state);
 945         ktime_t  kt1, kt2;
 946         s64 idle_time_ns;
 947         s64 idle_time;
 948
 949
 950         pr = __get_cpu_var(processors);
 951
 952         if (unlikely(!pr))
 953                 return 0;
 954
 955         if (acpi_idle_suspend)
 956                 return(acpi_idle_enter_c1(dev, state));
 957
 958         if (!cx->bm_sts_skip && acpi_idle_bm_check()) {
 959                 if (dev->safe_state) {
 960                         dev->last_state = dev->safe_state;
 961                         return dev->safe_state->enter(dev, dev->safe_state);
 962                 } else {
 963                         local_irq_disable();
 964                         acpi_safe_halt();
 965                         local_irq_enable();
 966                         return 0;
 967                 }
 968         }
 969
 970         local_irq_disable();
 971
 972         if (cx->entry_method != ACPI_CSTATE_FFH) {
 973                 current_thread_info()->status &= ~TS_POLLING;
 974                 /*
 975                  * TS_POLLING-cleared state must be visible before we test
 976                  * NEED_RESCHED:
 977                  */
 978                 smp_mb();
 979
 980                 if (unlikely(need_resched())) {
 981                         current_thread_info()->status |= TS_POLLING;
 982                         local_irq_enable();
 983                         return 0;
 984                 }
 985         }
 986
 987         acpi_unlazy_tlb(smp_processor_id());
 988
 989         /* Tell the scheduler that we are going deep-idle: */
 990         sched_clock_idle_sleep_event();
 991         /*
 992          * Must be done before busmaster disable as we might need to
 993          * access HPET !
 994          */
 995         lapic_timer_state_broadcast(pr, cx, 1);
 996
 997         kt1 = ktime_get_real();
 998         /*
 999          * disable bus master
1000          * bm_check implies we need ARB_DIS
1001          * !bm_check implies we need cache flush
1002          * bm_control implies whether we can do ARB_DIS
1003          *
1004          * That leaves a case where bm_check is set and bm_control is
1005          * not set. In that case we cannot do much, we enter C3
1006          * without doing anything.
1007          */
1008         if (pr->flags.bm_check && pr->flags.bm_control) {
1009                 spin_lock(&c3_lock);
1010                 c3_cpu_count++;
1011                 /* Disable bus master arbitration when all CPUs are in C3 */
1012                 if (c3_cpu_count == num_online_cpus())
1013                         acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
1014                 spin_unlock(&c3_lock);
1015         } else if (!pr->flags.bm_check) {
1016                 ACPI_FLUSH_CPU_CACHE();
1017         }
1018
1019         acpi_idle_do_entry(cx);
1020
1021         /* Re-enable bus master arbitration */
1022         if (pr->flags.bm_check && pr->flags.bm_control) {
1023                 spin_lock(&c3_lock);
1024                 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
1025                 c3_cpu_count--;
1026                 spin_unlock(&c3_lock);
1027         }
1028         kt2 = ktime_get_real();
1029         idle_time_ns = ktime_to_ns(ktime_sub(kt2, kt1));
1030         idle_time = idle_time_ns;
1031         do_div(idle_time, NSEC_PER_USEC);
1032
1033         /* Tell the scheduler how much we idled: */
1034         sched_clock_idle_wakeup_event(idle_time_ns);
1035
1036         local_irq_enable();
1037         if (cx->entry_method != ACPI_CSTATE_FFH)
1038                 current_thread_info()->status |= TS_POLLING;
1039
1040         cx->usage++;
1041
1042         lapic_timer_state_broadcast(pr, cx, 0);
1043         cx->time += idle_time;
1044         return idle_time;
1045 }
1046
1047 struct cpuidle_driver acpi_idle_driver = {
1048         .name =         "acpi_idle",
1049         .owner =        THIS_MODULE,
1050 };
1051
1052 /**
1053  * acpi_processor_setup_cpuidle - prepares and configures CPUIDLE
1054  * @pr: the ACPI processor
1055  */
1056 static int acpi_processor_setup_cpuidle(struct acpi_processor *pr)
1057 {
1058         int i, count = CPUIDLE_DRIVER_STATE_START;
1059         struct acpi_processor_cx *cx;
1060         struct cpuidle_state *state;
1061         struct cpuidle_device *dev = &pr->power.dev;
1062
1063         if (!pr->flags.power_setup_done)
1064                 return -EINVAL;
1065
1066         if (pr->flags.power == 0) {
1067                 return -EINVAL;
1068         }
1069
1070         dev->cpu = pr->id;
1071         for (i = 0; i < CPUIDLE_STATE_MAX; i++) {
1072                 dev->states[i].name[0] = '\0';
1073                 dev->states[i].desc[0] = '\0';
1074         }
1075
1076         if (max_cstate == 0)
1077                 max_cstate = 1;
1078
1079         for (i = 1; i < ACPI_PROCESSOR_MAX_POWER && i <= max_cstate; i++) {
1080                 cx = &pr->power.states[i];
1081                 state = &dev->states[count];
1082
1083                 if (!cx->valid)
1084                         continue;
1085
1086 #ifdef CONFIG_HOTPLUG_CPU
1087                 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
1088                     !pr->flags.has_cst &&
1089                     !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
1090                         continue;
1091 #endif
1092                 cpuidle_set_statedata(state, cx);
1093
1094                 snprintf(state->name, CPUIDLE_NAME_LEN, "C%d", i);
1095                 strncpy(state->desc, cx->desc, CPUIDLE_DESC_LEN);
1096                 state->exit_latency = cx->latency;
1097                 state->target_residency = cx->latency * latency_factor;
1098                 state->power_usage = cx->power;
1099
1100                 state->flags = 0;
1101                 switch (cx->type) {
1102                         case ACPI_STATE_C1:
1103                         state->flags |= CPUIDLE_FLAG_SHALLOW;
1104                         if (cx->entry_method == ACPI_CSTATE_FFH)
1105                                 state->flags |= CPUIDLE_FLAG_TIME_VALID;
1106
1107                         state->enter = acpi_idle_enter_c1;
1108                         dev->safe_state = state;
1109                         break;
1110
1111                         case ACPI_STATE_C2:
1112                         state->flags |= CPUIDLE_FLAG_BALANCED;
1113                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1114                         state->enter = acpi_idle_enter_simple;
1115                         dev->safe_state = state;
1116                         break;
1117
1118                         case ACPI_STATE_C3:
1119                         state->flags |= CPUIDLE_FLAG_DEEP;
1120                         state->flags |= CPUIDLE_FLAG_TIME_VALID;
1121                         state->flags |= CPUIDLE_FLAG_CHECK_BM;
1122                         state->enter = pr->flags.bm_check ?
1123                                         acpi_idle_enter_bm :
1124                                         acpi_idle_enter_simple;
1125                         break;
1126                 }
1127
1128                 count++;
1129                 if (count == CPUIDLE_STATE_MAX)
1130                         break;
1131         }
1132
1133         dev->state_count = count;
1134
1135         if (!count)
1136                 return -EINVAL;
1137
1138         return 0;
1139 }
1140
1141 int acpi_processor_cst_has_changed(struct acpi_processor *pr)
1142 {
1143         int ret = 0;
1144
1145         if (boot_option_idle_override)
1146                 return 0;
1147
1148         if (!pr)
1149                 return -EINVAL;
1150
1151         if (nocst) {
1152                 return -ENODEV;
1153         }
1154
1155         if (!pr->flags.power_setup_done)
1156                 return -ENODEV;
1157
1158         cpuidle_pause_and_lock();
1159         cpuidle_disable_device(&pr->power.dev);
1160         acpi_processor_get_power_info(pr);
1161         if (pr->flags.power) {
1162                 acpi_processor_setup_cpuidle(pr);
1163                 ret = cpuidle_enable_device(&pr->power.dev);
1164         }
1165         cpuidle_resume_and_unlock();
1166
1167         return ret;
1168 }
1169
1170 int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
1171                               struct acpi_device *device)
1172 {
1173         acpi_status status = 0;
1174         static int first_run;
1175 #ifdef CONFIG_ACPI_PROCFS
1176         struct proc_dir_entry *entry = NULL;
1177 #endif
1178
1179         if (boot_option_idle_override)
1180                 return 0;
1181
1182         if (!first_run) {
1183                 if (idle_halt) {
1184                         /*
1185                          * When the boot option of "idle=halt" is added, halt
1186                          * is used for CPU IDLE.
1187                          * In such case C2/C3 is meaningless. So the max_cstate
1188                          * is set to one.
1189                          */
1190                         max_cstate = 1;
1191                 }
1192                 dmi_check_system(processor_power_dmi_table);
1193                 max_cstate = acpi_processor_cstate_check(max_cstate);
1194                 if (max_cstate < ACPI_C_STATES_MAX)
1195                         printk(KERN_NOTICE
1196                                "ACPI: processor limited to max C-state %d\n",
1197                                max_cstate);
1198                 first_run++;
1199         }
1200
1201         if (!pr)
1202                 return -EINVAL;
1203
1204         if (acpi_gbl_FADT.cst_control && !nocst) {
1205                 status =
1206                     acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
1207                 if (ACPI_FAILURE(status)) {
1208                         ACPI_EXCEPTION((AE_INFO, status,
1209                                         "Notifying BIOS of _CST ability failed"));
1210                 }
1211         }
1212
1213         acpi_processor_get_power_info(pr);
1214         pr->flags.power_setup_done = 1;
1215
1216         /*
1217          * Install the idle handler if processor power management is supported.
1218          * Note that we use previously set idle handler will be used on
1219          * platforms that only support C1.
1220          */
1221         if (pr->flags.power) {
1222                 acpi_processor_setup_cpuidle(pr);
1223                 if (cpuidle_register_device(&pr->power.dev))
1224                         return -EIO;
1225         }
1226 #ifdef CONFIG_ACPI_PROCFS
1227         /* 'power' [R] */
1228         entry = proc_create_data(ACPI_PROCESSOR_FILE_POWER,
1229                                  S_IRUGO, acpi_device_dir(device),
1230                                  &acpi_processor_power_fops,
1231                                  acpi_driver_data(device));
1232         if (!entry)
1233                 return -EIO;
1234 #endif
1235         return 0;
1236 }
1237
1238 int acpi_processor_power_exit(struct acpi_processor *pr,
1239                               struct acpi_device *device)
1240 {
1241         if (boot_option_idle_override)
1242                 return 0;
1243
1244         cpuidle_unregister_device(&pr->power.dev);
1245         pr->flags.power_setup_done = 0;
1246
1247 #ifdef CONFIG_ACPI_PROCFS
1248         if (acpi_device_dir(device))
1249                 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1250                                   acpi_device_dir(device));
1251 #endif
1252
1253         return 0;
1254 }