treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 157
[sfrench/cifs-2.6.git] / 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 }