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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Dominik Brodowskic5ab81c2006-06-24 19:37:00 -04006 * Copyright (C) 2004, 2005 Dominik Brodowski <linux@brodo.de>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 * Copyright (C) 2004 Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
8 * - Added processor hotplug support
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -04009 * Copyright (C) 2005 Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10 * - Added support for C3 on SMP
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 *
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/proc_fs.h>
36#include <linux/seq_file.h>
37#include <linux/acpi.h>
38#include <linux/dmi.h>
39#include <linux/moduleparam.h>
Tim Schmielau4e57b682005-10-30 15:03:48 -080040#include <linux/sched.h> /* need_resched() */
Arjan van de Ven5c875792006-09-30 23:27:17 -070041#include <linux/latency.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Thomas Gleixner5c95d3f2007-02-15 23:25:53 -050043/*
44 * Include the apic definitions for x86 to have the APIC timer related defines
45 * available also for UP (on SMP it gets magically included via linux/smp.h).
46 */
47#ifdef CONFIG_X86
48#include <asm/apic.h>
49#endif
50
Linus Torvalds1da177e2005-04-16 15:20:36 -070051#include <asm/io.h>
52#include <asm/uaccess.h>
53
54#include <acpi/acpi_bus.h>
55#include <acpi/processor.h>
56
57#define ACPI_PROCESSOR_COMPONENT 0x01000000
58#define ACPI_PROCESSOR_CLASS "processor"
59#define ACPI_PROCESSOR_DRIVER_NAME "ACPI Processor Driver"
60#define _COMPONENT ACPI_PROCESSOR_COMPONENT
Len Brown4be44fc2005-08-05 00:44:28 -040061ACPI_MODULE_NAME("acpi_processor")
Linus Torvalds1da177e2005-04-16 15:20:36 -070062#define ACPI_PROCESSOR_FILE_POWER "power"
Linus Torvalds1da177e2005-04-16 15:20:36 -070063#define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
64#define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
65#define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
Andreas Mohrb6835052006-04-27 05:25:00 -040066static void (*pm_idle_save) (void) __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070067module_param(max_cstate, uint, 0644);
68
Andreas Mohrb6835052006-04-27 05:25:00 -040069static unsigned int nocst __read_mostly;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070module_param(nocst, uint, 0000);
71
72/*
73 * bm_history -- bit-mask with a bit per jiffy of bus-master activity
74 * 1000 HZ: 0xFFFFFFFF: 32 jiffies = 32ms
75 * 800 HZ: 0xFFFFFFFF: 32 jiffies = 40ms
76 * 100 HZ: 0x0000000F: 4 jiffies = 40ms
77 * reduce history for more aggressive entry into C3
78 */
Andreas Mohrb6835052006-04-27 05:25:00 -040079static unsigned int bm_history __read_mostly =
Len Brown4be44fc2005-08-05 00:44:28 -040080 (HZ >= 800 ? 0xFFFFFFFF : ((1U << (HZ / 25)) - 1));
Linus Torvalds1da177e2005-04-16 15:20:36 -070081module_param(bm_history, uint, 0644);
82/* --------------------------------------------------------------------------
83 Power Management
84 -------------------------------------------------------------------------- */
85
86/*
87 * IBM ThinkPad R40e crashes mysteriously when going into C2 or C3.
88 * For now disable this. Probably a bug somewhere else.
89 *
90 * To skip this limit, boot/load with a large max_cstate limit.
91 */
David Shaohua Li335f16b2005-06-22 18:37:00 -040092static int set_max_cstate(struct dmi_system_id *id)
Linus Torvalds1da177e2005-04-16 15:20:36 -070093{
94 if (max_cstate > ACPI_PROCESSOR_MAX_POWER)
95 return 0;
96
Len Brown3d356002005-08-03 00:22:52 -040097 printk(KERN_NOTICE PREFIX "%s detected - limiting to C%ld max_cstate."
Len Brown4be44fc2005-08-05 00:44:28 -040098 " Override with \"processor.max_cstate=%d\"\n", id->ident,
99 (long)id->driver_data, ACPI_PROCESSOR_MAX_POWER + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100
Len Brown3d356002005-08-03 00:22:52 -0400101 max_cstate = (long)id->driver_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102
103 return 0;
104}
105
Ashok Raj7ded5682006-02-03 21:51:23 +0100106/* Actually this shouldn't be __cpuinitdata, would be better to fix the
107 callers to only run once -AK */
108static struct dmi_system_id __cpuinitdata processor_power_dmi_table[] = {
Thomas Rosner876c1842006-01-06 01:31:00 -0500109 { set_max_cstate, "IBM ThinkPad R40e", {
110 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
Bartlomiej Swierczf8313352006-05-29 07:16:00 -0400111 DMI_MATCH(DMI_BIOS_VERSION,"1SET70WW")}, (void *)1},
112 { set_max_cstate, "IBM ThinkPad R40e", {
113 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
Thomas Rosner876c1842006-01-06 01:31:00 -0500114 DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW")}, (void *)1},
115 { set_max_cstate, "IBM ThinkPad R40e", {
116 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
117 DMI_MATCH(DMI_BIOS_VERSION,"1SET43WW") }, (void*)1},
118 { set_max_cstate, "IBM ThinkPad R40e", {
119 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
120 DMI_MATCH(DMI_BIOS_VERSION,"1SET45WW") }, (void*)1},
121 { set_max_cstate, "IBM ThinkPad R40e", {
122 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
123 DMI_MATCH(DMI_BIOS_VERSION,"1SET47WW") }, (void*)1},
124 { set_max_cstate, "IBM ThinkPad R40e", {
125 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
126 DMI_MATCH(DMI_BIOS_VERSION,"1SET50WW") }, (void*)1},
127 { set_max_cstate, "IBM ThinkPad R40e", {
128 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
129 DMI_MATCH(DMI_BIOS_VERSION,"1SET52WW") }, (void*)1},
130 { set_max_cstate, "IBM ThinkPad R40e", {
131 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
132 DMI_MATCH(DMI_BIOS_VERSION,"1SET55WW") }, (void*)1},
133 { set_max_cstate, "IBM ThinkPad R40e", {
134 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
135 DMI_MATCH(DMI_BIOS_VERSION,"1SET56WW") }, (void*)1},
136 { set_max_cstate, "IBM ThinkPad R40e", {
137 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
138 DMI_MATCH(DMI_BIOS_VERSION,"1SET59WW") }, (void*)1},
139 { set_max_cstate, "IBM ThinkPad R40e", {
140 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
141 DMI_MATCH(DMI_BIOS_VERSION,"1SET60WW") }, (void*)1},
142 { set_max_cstate, "IBM ThinkPad R40e", {
143 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
144 DMI_MATCH(DMI_BIOS_VERSION,"1SET61WW") }, (void*)1},
145 { set_max_cstate, "IBM ThinkPad R40e", {
146 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
147 DMI_MATCH(DMI_BIOS_VERSION,"1SET62WW") }, (void*)1},
148 { set_max_cstate, "IBM ThinkPad R40e", {
149 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
150 DMI_MATCH(DMI_BIOS_VERSION,"1SET64WW") }, (void*)1},
151 { set_max_cstate, "IBM ThinkPad R40e", {
152 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
153 DMI_MATCH(DMI_BIOS_VERSION,"1SET65WW") }, (void*)1},
154 { set_max_cstate, "IBM ThinkPad R40e", {
155 DMI_MATCH(DMI_BIOS_VENDOR,"IBM"),
156 DMI_MATCH(DMI_BIOS_VERSION,"1SET68WW") }, (void*)1},
157 { set_max_cstate, "Medion 41700", {
158 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
159 DMI_MATCH(DMI_BIOS_VERSION,"R01-A1J")}, (void *)1},
160 { set_max_cstate, "Clevo 5600D", {
161 DMI_MATCH(DMI_BIOS_VENDOR,"Phoenix Technologies LTD"),
162 DMI_MATCH(DMI_BIOS_VERSION,"SHE845M0.86C.0013.D.0302131307")},
Len Brown4be44fc2005-08-05 00:44:28 -0400163 (void *)2},
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 {},
165};
166
Len Brown4be44fc2005-08-05 00:44:28 -0400167static inline u32 ticks_elapsed(u32 t1, u32 t2)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168{
169 if (t2 >= t1)
170 return (t2 - t1);
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300171 else if (!(acpi_gbl_FADT.flags & ACPI_FADT_32BIT_TIMER))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700172 return (((0x00FFFFFF - t1) + t2) & 0x00FFFFFF);
173 else
174 return ((0xFFFFFFFF - t1) + t2);
175}
176
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177static void
Len Brown4be44fc2005-08-05 00:44:28 -0400178acpi_processor_power_activate(struct acpi_processor *pr,
179 struct acpi_processor_cx *new)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180{
Len Brown4be44fc2005-08-05 00:44:28 -0400181 struct acpi_processor_cx *old;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182
183 if (!pr || !new)
184 return;
185
186 old = pr->power.state;
187
188 if (old)
189 old->promotion.count = 0;
Len Brown4be44fc2005-08-05 00:44:28 -0400190 new->demotion.count = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191
192 /* Cleanup from old state. */
193 if (old) {
194 switch (old->type) {
195 case ACPI_STATE_C3:
196 /* Disable bus master reload */
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400197 if (new->type != ACPI_STATE_C3 && pr->flags.bm_check)
Bob Moored8c71b62007-02-02 19:48:21 +0300198 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199 break;
200 }
201 }
202
203 /* Prepare to use new state. */
204 switch (new->type) {
205 case ACPI_STATE_C3:
206 /* Enable bus master reload */
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400207 if (old->type != ACPI_STATE_C3 && pr->flags.bm_check)
Bob Moored8c71b62007-02-02 19:48:21 +0300208 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 break;
210 }
211
212 pr->power.state = new;
213
214 return;
215}
216
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800217static void acpi_safe_halt(void)
218{
Andi Kleen495ab9c2006-06-26 13:59:11 +0200219 current_thread_info()->status &= ~TS_POLLING;
Ingo Molnar0888f062006-12-22 01:11:56 -0800220 /*
221 * TS_POLLING-cleared state must be visible before we
222 * test NEED_RESCHED:
223 */
224 smp_mb();
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800225 if (!need_resched())
226 safe_halt();
Andi Kleen495ab9c2006-06-26 13:59:11 +0200227 current_thread_info()->status |= TS_POLLING;
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800228}
229
Len Brown4be44fc2005-08-05 00:44:28 -0400230static atomic_t c3_cpu_count;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700232/* Common C-state entry for C2, C3, .. */
233static void acpi_cstate_enter(struct acpi_processor_cx *cstate)
234{
235 if (cstate->space_id == ACPI_CSTATE_FFH) {
236 /* Call into architectural FFH based C-state */
237 acpi_processor_ffh_cstate_enter(cstate);
238 } else {
239 int unused;
240 /* IO port based C-state */
241 inb(cstate->address);
242 /* Dummy wait op - must do something useless after P_LVL2 read
243 because chipsets cannot guarantee that STPCLK# signal
244 gets asserted in time to freeze execution properly. */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300245 unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700246 }
247}
248
Len Brown4be44fc2005-08-05 00:44:28 -0400249static void acpi_processor_idle(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250{
Len Brown4be44fc2005-08-05 00:44:28 -0400251 struct acpi_processor *pr = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 struct acpi_processor_cx *cx = NULL;
253 struct acpi_processor_cx *next_state = NULL;
Len Brown4be44fc2005-08-05 00:44:28 -0400254 int sleep_ticks = 0;
255 u32 t1, t2 = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800257 pr = processors[smp_processor_id()];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 if (!pr)
259 return;
260
261 /*
262 * Interrupts must be disabled during bus mastering calculations and
263 * for C2/C3 transitions.
264 */
265 local_irq_disable();
266
267 /*
268 * Check whether we truly need to go idle, or should
269 * reschedule:
270 */
271 if (unlikely(need_resched())) {
272 local_irq_enable();
273 return;
274 }
275
276 cx = pr->power.state;
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800277 if (!cx) {
278 if (pm_idle_save)
279 pm_idle_save();
280 else
281 acpi_safe_halt();
282 return;
283 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284
285 /*
286 * Check BM Activity
287 * -----------------
288 * Check for bus mastering activity (if required), record, and check
289 * for demotion.
290 */
291 if (pr->flags.bm_check) {
Len Brown4be44fc2005-08-05 00:44:28 -0400292 u32 bm_status = 0;
293 unsigned long diff = jiffies - pr->power.bm_check_timestamp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294
Dominik Brodowskic5ab81c2006-06-24 19:37:00 -0400295 if (diff > 31)
296 diff = 31;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297
Dominik Brodowskic5ab81c2006-06-24 19:37:00 -0400298 pr->power.bm_activity <<= diff;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299
Bob Moored8c71b62007-02-02 19:48:21 +0300300 acpi_get_register(ACPI_BITREG_BUS_MASTER_STATUS, &bm_status);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 if (bm_status) {
Dominik Brodowskic5ab81c2006-06-24 19:37:00 -0400302 pr->power.bm_activity |= 0x1;
Bob Moored8c71b62007-02-02 19:48:21 +0300303 acpi_set_register(ACPI_BITREG_BUS_MASTER_STATUS, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304 }
305 /*
306 * PIIX4 Erratum #18: Note that BM_STS doesn't always reflect
307 * the true state of bus mastering activity; forcing us to
308 * manually check the BMIDEA bit of each IDE channel.
309 */
310 else if (errata.piix4.bmisx) {
311 if ((inb_p(errata.piix4.bmisx + 0x02) & 0x01)
Len Brown4be44fc2005-08-05 00:44:28 -0400312 || (inb_p(errata.piix4.bmisx + 0x0A) & 0x01))
Dominik Brodowskic5ab81c2006-06-24 19:37:00 -0400313 pr->power.bm_activity |= 0x1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700314 }
315
316 pr->power.bm_check_timestamp = jiffies;
317
318 /*
Dominik Brodowskic4a001b2006-06-24 19:37:00 -0400319 * If bus mastering is or was active this jiffy, demote
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 * to avoid a faulty transition. Note that the processor
321 * won't enter a low-power state during this call (to this
Dominik Brodowskic4a001b2006-06-24 19:37:00 -0400322 * function) but should upon the next.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 *
324 * TBD: A better policy might be to fallback to the demotion
325 * state (use it for this quantum only) istead of
326 * demoting -- and rely on duration as our sole demotion
327 * qualification. This may, however, introduce DMA
328 * issues (e.g. floppy DMA transfer overrun/underrun).
329 */
Dominik Brodowskic4a001b2006-06-24 19:37:00 -0400330 if ((pr->power.bm_activity & 0x1) &&
331 cx->demotion.threshold.bm) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 local_irq_enable();
333 next_state = cx->demotion.state;
334 goto end;
335 }
336 }
337
Venkatesh Pallipadi4c033552005-09-15 12:20:00 -0400338#ifdef CONFIG_HOTPLUG_CPU
339 /*
340 * Check for P_LVL2_UP flag before entering C2 and above on
341 * an SMP system. We do it here instead of doing it at _CST/P_LVL
342 * detection phase, to work cleanly with logical CPU hotplug.
343 */
344 if ((cx->type != ACPI_STATE_C1) && (num_online_cpus() > 1) &&
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300345 !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
David Shaohua Li1e483962005-12-01 17:00:00 -0500346 cx = &pr->power.states[ACPI_STATE_C1];
Venkatesh Pallipadi4c033552005-09-15 12:20:00 -0400347#endif
David Shaohua Li1e483962005-12-01 17:00:00 -0500348
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 /*
350 * Sleep:
351 * ------
352 * Invoke the current Cx state to put the processor to sleep.
353 */
Nick Piggin2a298a32005-12-02 12:44:19 +1100354 if (cx->type == ACPI_STATE_C2 || cx->type == ACPI_STATE_C3) {
Andi Kleen495ab9c2006-06-26 13:59:11 +0200355 current_thread_info()->status &= ~TS_POLLING;
Ingo Molnar0888f062006-12-22 01:11:56 -0800356 /*
357 * TS_POLLING-cleared state must be visible before we
358 * test NEED_RESCHED:
359 */
360 smp_mb();
Nick Piggin2a298a32005-12-02 12:44:19 +1100361 if (need_resched()) {
Andi Kleen495ab9c2006-06-26 13:59:11 +0200362 current_thread_info()->status |= TS_POLLING;
Linus Torvaldsaf2eb172005-12-02 23:09:06 -0800363 local_irq_enable();
Nick Piggin2a298a32005-12-02 12:44:19 +1100364 return;
365 }
366 }
367
Linus Torvalds1da177e2005-04-16 15:20:36 -0700368 switch (cx->type) {
369
370 case ACPI_STATE_C1:
371 /*
372 * Invoke C1.
373 * Use the appropriate idle routine, the one that would
374 * be used without acpi C-states.
375 */
376 if (pm_idle_save)
377 pm_idle_save();
378 else
Nick Piggin64c7c8f2005-11-08 21:39:04 -0800379 acpi_safe_halt();
380
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 /*
Len Brown4be44fc2005-08-05 00:44:28 -0400382 * TBD: Can't get time duration while in C1, as resumes
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 * go to an ISR rather than here. Need to instrument
384 * base interrupt handler.
385 */
386 sleep_ticks = 0xFFFFFFFF;
387 break;
388
389 case ACPI_STATE_C2:
390 /* Get start time (ticks) */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300391 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 /* Invoke C2 */
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700393 acpi_cstate_enter(cx);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 /* Get end time (ticks) */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300395 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
john stultz539eb112006-06-26 00:25:10 -0700396
397#ifdef CONFIG_GENERIC_TIME
398 /* TSC halts in C2, so notify users */
399 mark_tsc_unstable();
400#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700401 /* Re-enable interrupts */
402 local_irq_enable();
Andi Kleen495ab9c2006-06-26 13:59:11 +0200403 current_thread_info()->status |= TS_POLLING;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 /* Compute time (ticks) that we were actually asleep */
Len Brown4be44fc2005-08-05 00:44:28 -0400405 sleep_ticks =
406 ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 break;
408
409 case ACPI_STATE_C3:
Len Brown4be44fc2005-08-05 00:44:28 -0400410
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400411 if (pr->flags.bm_check) {
412 if (atomic_inc_return(&c3_cpu_count) ==
Len Brown4be44fc2005-08-05 00:44:28 -0400413 num_online_cpus()) {
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400414 /*
415 * All CPUs are trying to go to C3
416 * Disable bus master arbitration
417 */
Bob Moored8c71b62007-02-02 19:48:21 +0300418 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 1);
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400419 }
420 } else {
421 /* SMP with no shared cache... Invalidate cache */
422 ACPI_FLUSH_CPU_CACHE();
423 }
Len Brown4be44fc2005-08-05 00:44:28 -0400424
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425 /* Get start time (ticks) */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300426 t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 /* Invoke C3 */
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700428 acpi_cstate_enter(cx);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 /* Get end time (ticks) */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300430 t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400431 if (pr->flags.bm_check) {
432 /* Enable bus master arbitration */
433 atomic_dec(&c3_cpu_count);
Bob Moored8c71b62007-02-02 19:48:21 +0300434 acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0);
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400435 }
436
john stultz539eb112006-06-26 00:25:10 -0700437#ifdef CONFIG_GENERIC_TIME
438 /* TSC halts in C3, so notify users */
439 mark_tsc_unstable();
440#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700441 /* Re-enable interrupts */
442 local_irq_enable();
Andi Kleen495ab9c2006-06-26 13:59:11 +0200443 current_thread_info()->status |= TS_POLLING;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444 /* Compute time (ticks) that we were actually asleep */
Len Brown4be44fc2005-08-05 00:44:28 -0400445 sleep_ticks =
446 ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 break;
448
449 default:
450 local_irq_enable();
451 return;
452 }
Dominik Brodowskia3c65982006-06-24 19:37:00 -0400453 cx->usage++;
454 if ((cx->type != ACPI_STATE_C1) && (sleep_ticks > 0))
455 cx->time += sleep_ticks;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
457 next_state = pr->power.state;
458
David Shaohua Li1e483962005-12-01 17:00:00 -0500459#ifdef CONFIG_HOTPLUG_CPU
460 /* Don't do promotion/demotion */
461 if ((cx->type == ACPI_STATE_C1) && (num_online_cpus() > 1) &&
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300462 !pr->flags.has_cst && !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED)) {
David Shaohua Li1e483962005-12-01 17:00:00 -0500463 next_state = cx;
464 goto end;
465 }
466#endif
467
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468 /*
469 * Promotion?
470 * ----------
471 * Track the number of longs (time asleep is greater than threshold)
472 * and promote when the count threshold is reached. Note that bus
473 * mastering activity may prevent promotions.
474 * Do not promote above max_cstate.
475 */
476 if (cx->promotion.state &&
477 ((cx->promotion.state - pr->power.states) <= max_cstate)) {
Arjan van de Ven5c875792006-09-30 23:27:17 -0700478 if (sleep_ticks > cx->promotion.threshold.ticks &&
479 cx->promotion.state->latency <= system_latency_constraint()) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700480 cx->promotion.count++;
Len Brown4be44fc2005-08-05 00:44:28 -0400481 cx->demotion.count = 0;
482 if (cx->promotion.count >=
483 cx->promotion.threshold.count) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 if (pr->flags.bm_check) {
Len Brown4be44fc2005-08-05 00:44:28 -0400485 if (!
486 (pr->power.bm_activity & cx->
487 promotion.threshold.bm)) {
488 next_state =
489 cx->promotion.state;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 goto end;
491 }
Len Brown4be44fc2005-08-05 00:44:28 -0400492 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 next_state = cx->promotion.state;
494 goto end;
495 }
496 }
497 }
498 }
499
500 /*
501 * Demotion?
502 * ---------
503 * Track the number of shorts (time asleep is less than time threshold)
504 * and demote when the usage threshold is reached.
505 */
506 if (cx->demotion.state) {
507 if (sleep_ticks < cx->demotion.threshold.ticks) {
508 cx->demotion.count++;
509 cx->promotion.count = 0;
510 if (cx->demotion.count >= cx->demotion.threshold.count) {
511 next_state = cx->demotion.state;
512 goto end;
513 }
514 }
515 }
516
Len Brown4be44fc2005-08-05 00:44:28 -0400517 end:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700518 /*
519 * Demote if current state exceeds max_cstate
Arjan van de Ven5c875792006-09-30 23:27:17 -0700520 * or if the latency of the current state is unacceptable
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 */
Arjan van de Ven5c875792006-09-30 23:27:17 -0700522 if ((pr->power.state - pr->power.states) > max_cstate ||
523 pr->power.state->latency > system_latency_constraint()) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524 if (cx->demotion.state)
525 next_state = cx->demotion.state;
526 }
527
528 /*
529 * New Cx State?
530 * -------------
531 * If we're going to start using a new Cx state we must clean up
532 * from the previous and prepare to use the new.
533 */
534 if (next_state != pr->power.state)
535 acpi_processor_power_activate(pr, next_state);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536}
537
Len Brown4be44fc2005-08-05 00:44:28 -0400538static int acpi_processor_set_power_policy(struct acpi_processor *pr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539{
540 unsigned int i;
541 unsigned int state_is_set = 0;
542 struct acpi_processor_cx *lower = NULL;
543 struct acpi_processor_cx *higher = NULL;
544 struct acpi_processor_cx *cx;
545
Linus Torvalds1da177e2005-04-16 15:20:36 -0700546
547 if (!pr)
Patrick Mocheld550d982006-06-27 00:41:40 -0400548 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549
550 /*
551 * This function sets the default Cx state policy (OS idle handler).
552 * Our scheme is to promote quickly to C2 but more conservatively
553 * to C3. We're favoring C2 for its characteristics of low latency
554 * (quick response), good power savings, and ability to allow bus
555 * mastering activity. Note that the Cx state policy is completely
556 * customizable and can be altered dynamically.
557 */
558
559 /* startup state */
Len Brown4be44fc2005-08-05 00:44:28 -0400560 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 cx = &pr->power.states[i];
562 if (!cx->valid)
563 continue;
564
565 if (!state_is_set)
566 pr->power.state = cx;
567 state_is_set++;
568 break;
Len Brown4be44fc2005-08-05 00:44:28 -0400569 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570
571 if (!state_is_set)
Patrick Mocheld550d982006-06-27 00:41:40 -0400572 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700573
574 /* demotion */
Len Brown4be44fc2005-08-05 00:44:28 -0400575 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700576 cx = &pr->power.states[i];
577 if (!cx->valid)
578 continue;
579
580 if (lower) {
581 cx->demotion.state = lower;
582 cx->demotion.threshold.ticks = cx->latency_ticks;
583 cx->demotion.threshold.count = 1;
584 if (cx->type == ACPI_STATE_C3)
585 cx->demotion.threshold.bm = bm_history;
586 }
587
588 lower = cx;
589 }
590
591 /* promotion */
592 for (i = (ACPI_PROCESSOR_MAX_POWER - 1); i > 0; i--) {
593 cx = &pr->power.states[i];
594 if (!cx->valid)
595 continue;
596
597 if (higher) {
Len Brown4be44fc2005-08-05 00:44:28 -0400598 cx->promotion.state = higher;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 cx->promotion.threshold.ticks = cx->latency_ticks;
600 if (cx->type >= ACPI_STATE_C2)
601 cx->promotion.threshold.count = 4;
602 else
603 cx->promotion.threshold.count = 10;
604 if (higher->type == ACPI_STATE_C3)
605 cx->promotion.threshold.bm = bm_history;
606 }
607
608 higher = cx;
609 }
610
Patrick Mocheld550d982006-06-27 00:41:40 -0400611 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700612}
613
Len Brown4be44fc2005-08-05 00:44:28 -0400614static int acpi_processor_get_power_info_fadt(struct acpi_processor *pr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700616
617 if (!pr)
Patrick Mocheld550d982006-06-27 00:41:40 -0400618 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619
620 if (!pr->pblk)
Patrick Mocheld550d982006-06-27 00:41:40 -0400621 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700622
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 /* if info is obtained from pblk/fadt, type equals state */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 pr->power.states[ACPI_STATE_C2].type = ACPI_STATE_C2;
625 pr->power.states[ACPI_STATE_C3].type = ACPI_STATE_C3;
626
Venkatesh Pallipadi4c033552005-09-15 12:20:00 -0400627#ifndef CONFIG_HOTPLUG_CPU
628 /*
629 * Check for P_LVL2_UP flag before entering C2 and above on
630 * an SMP system.
631 */
Alexey Starikovskiyad718602007-02-02 19:48:19 +0300632 if ((num_online_cpus() > 1) &&
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300633 !(acpi_gbl_FADT.flags & ACPI_FADT_C2_MP_SUPPORTED))
Patrick Mocheld550d982006-06-27 00:41:40 -0400634 return -ENODEV;
Venkatesh Pallipadi4c033552005-09-15 12:20:00 -0400635#endif
636
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 /* determine C2 and C3 address from pblk */
638 pr->power.states[ACPI_STATE_C2].address = pr->pblk + 4;
639 pr->power.states[ACPI_STATE_C3].address = pr->pblk + 5;
640
641 /* determine latencies from FADT */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300642 pr->power.states[ACPI_STATE_C2].latency = acpi_gbl_FADT.C2latency;
643 pr->power.states[ACPI_STATE_C3].latency = acpi_gbl_FADT.C3latency;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644
645 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
646 "lvl2[0x%08x] lvl3[0x%08x]\n",
647 pr->power.states[ACPI_STATE_C2].address,
648 pr->power.states[ACPI_STATE_C3].address));
649
Patrick Mocheld550d982006-06-27 00:41:40 -0400650 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651}
652
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700653static int acpi_processor_get_power_info_default(struct acpi_processor *pr)
Venkatesh Pallipadiacf05f42005-03-31 23:23:15 -0500654{
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700655 if (!pr->power.states[ACPI_STATE_C1].valid) {
656 /* set the first C-State to C1 */
657 /* all processors need to support C1 */
658 pr->power.states[ACPI_STATE_C1].type = ACPI_STATE_C1;
659 pr->power.states[ACPI_STATE_C1].valid = 1;
660 }
661 /* the C0 state only exists as a filler in our array */
Venkatesh Pallipadiacf05f42005-03-31 23:23:15 -0500662 pr->power.states[ACPI_STATE_C0].valid = 1;
Patrick Mocheld550d982006-06-27 00:41:40 -0400663 return 0;
Venkatesh Pallipadiacf05f42005-03-31 23:23:15 -0500664}
665
Len Brown4be44fc2005-08-05 00:44:28 -0400666static int acpi_processor_get_power_info_cst(struct acpi_processor *pr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700667{
Len Brown4be44fc2005-08-05 00:44:28 -0400668 acpi_status status = 0;
669 acpi_integer count;
Janosch Machowinskicf824782005-08-20 08:02:00 -0400670 int current_count;
Len Brown4be44fc2005-08-05 00:44:28 -0400671 int i;
672 struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
673 union acpi_object *cst;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700674
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676 if (nocst)
Patrick Mocheld550d982006-06-27 00:41:40 -0400677 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700679 current_count = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680
681 status = acpi_evaluate_object(pr->handle, "_CST", NULL, &buffer);
682 if (ACPI_FAILURE(status)) {
683 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "No _CST, giving up\n"));
Patrick Mocheld550d982006-06-27 00:41:40 -0400684 return -ENODEV;
Len Brown4be44fc2005-08-05 00:44:28 -0400685 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686
Jan Engelhardt50dd0962006-10-01 00:28:50 +0200687 cst = buffer.pointer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688
689 /* There must be at least 2 elements */
690 if (!cst || (cst->type != ACPI_TYPE_PACKAGE) || cst->package.count < 2) {
Len Brown64684632006-06-26 23:41:38 -0400691 printk(KERN_ERR PREFIX "not enough elements in _CST\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700692 status = -EFAULT;
693 goto end;
694 }
695
696 count = cst->package.elements[0].integer.value;
697
698 /* Validate number of power states. */
699 if (count < 1 || count != cst->package.count - 1) {
Len Brown64684632006-06-26 23:41:38 -0400700 printk(KERN_ERR PREFIX "count given by _CST is not valid\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701 status = -EFAULT;
702 goto end;
703 }
704
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 /* Tell driver that at least _CST is supported. */
706 pr->flags.has_cst = 1;
707
708 for (i = 1; i <= count; i++) {
709 union acpi_object *element;
710 union acpi_object *obj;
711 struct acpi_power_register *reg;
712 struct acpi_processor_cx cx;
713
714 memset(&cx, 0, sizeof(cx));
715
Jan Engelhardt50dd0962006-10-01 00:28:50 +0200716 element = &(cst->package.elements[i]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717 if (element->type != ACPI_TYPE_PACKAGE)
718 continue;
719
720 if (element->package.count != 4)
721 continue;
722
Jan Engelhardt50dd0962006-10-01 00:28:50 +0200723 obj = &(element->package.elements[0]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724
725 if (obj->type != ACPI_TYPE_BUFFER)
726 continue;
727
Len Brown4be44fc2005-08-05 00:44:28 -0400728 reg = (struct acpi_power_register *)obj->buffer.pointer;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729
730 if (reg->space_id != ACPI_ADR_SPACE_SYSTEM_IO &&
Len Brown4be44fc2005-08-05 00:44:28 -0400731 (reg->space_id != ACPI_ADR_SPACE_FIXED_HARDWARE))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700732 continue;
733
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 /* There should be an easy way to extract an integer... */
Jan Engelhardt50dd0962006-10-01 00:28:50 +0200735 obj = &(element->package.elements[1]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736 if (obj->type != ACPI_TYPE_INTEGER)
737 continue;
738
739 cx.type = obj->integer.value;
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700740 /*
741 * Some buggy BIOSes won't list C1 in _CST -
742 * Let acpi_processor_get_power_info_default() handle them later
743 */
744 if (i == 1 && cx.type != ACPI_STATE_C1)
745 current_count++;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700746
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700747 cx.address = reg->address;
748 cx.index = current_count + 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700750 cx.space_id = ACPI_CSTATE_SYSTEMIO;
751 if (reg->space_id == ACPI_ADR_SPACE_FIXED_HARDWARE) {
752 if (acpi_processor_ffh_cstate_probe
753 (pr->id, &cx, reg) == 0) {
754 cx.space_id = ACPI_CSTATE_FFH;
755 } else if (cx.type != ACPI_STATE_C1) {
756 /*
757 * C1 is a special case where FIXED_HARDWARE
758 * can be handled in non-MWAIT way as well.
759 * In that case, save this _CST entry info.
760 * That is, we retain space_id of SYSTEM_IO for
761 * halt based C1.
762 * Otherwise, ignore this info and continue.
763 */
764 continue;
765 }
766 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767
Jan Engelhardt50dd0962006-10-01 00:28:50 +0200768 obj = &(element->package.elements[2]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 if (obj->type != ACPI_TYPE_INTEGER)
770 continue;
771
772 cx.latency = obj->integer.value;
773
Jan Engelhardt50dd0962006-10-01 00:28:50 +0200774 obj = &(element->package.elements[3]);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700775 if (obj->type != ACPI_TYPE_INTEGER)
776 continue;
777
778 cx.power = obj->integer.value;
779
Janosch Machowinskicf824782005-08-20 08:02:00 -0400780 current_count++;
781 memcpy(&(pr->power.states[current_count]), &cx, sizeof(cx));
782
783 /*
784 * We support total ACPI_PROCESSOR_MAX_POWER - 1
785 * (From 1 through ACPI_PROCESSOR_MAX_POWER - 1)
786 */
787 if (current_count >= (ACPI_PROCESSOR_MAX_POWER - 1)) {
788 printk(KERN_WARNING
789 "Limiting number of power states to max (%d)\n",
790 ACPI_PROCESSOR_MAX_POWER);
791 printk(KERN_WARNING
792 "Please increase ACPI_PROCESSOR_MAX_POWER if needed.\n");
793 break;
794 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700795 }
796
Len Brown4be44fc2005-08-05 00:44:28 -0400797 ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Found %d power states\n",
Janosch Machowinskicf824782005-08-20 08:02:00 -0400798 current_count));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700799
800 /* Validate number of power states discovered */
Janosch Machowinskicf824782005-08-20 08:02:00 -0400801 if (current_count < 2)
Venkatesh Pallipadi6d93c642005-09-15 12:19:00 -0400802 status = -EFAULT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700803
Len Brown4be44fc2005-08-05 00:44:28 -0400804 end:
Len Brown02438d82006-06-30 03:19:10 -0400805 kfree(buffer.pointer);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700806
Patrick Mocheld550d982006-06-27 00:41:40 -0400807 return status;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700808}
809
Linus Torvalds1da177e2005-04-16 15:20:36 -0700810static void acpi_processor_power_verify_c2(struct acpi_processor_cx *cx)
811{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812
813 if (!cx->address)
Patrick Mocheld550d982006-06-27 00:41:40 -0400814 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700815
816 /*
817 * C2 latency must be less than or equal to 100
818 * microseconds.
819 */
820 else if (cx->latency > ACPI_PROCESSOR_MAX_C2_LATENCY) {
821 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
Len Brown4be44fc2005-08-05 00:44:28 -0400822 "latency too large [%d]\n", cx->latency));
Patrick Mocheld550d982006-06-27 00:41:40 -0400823 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824 }
825
Linus Torvalds1da177e2005-04-16 15:20:36 -0700826 /*
827 * Otherwise we've met all of our C2 requirements.
828 * Normalize the C2 latency to expidite policy
829 */
830 cx->valid = 1;
831 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
832
Patrick Mocheld550d982006-06-27 00:41:40 -0400833 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700834}
835
Len Brown4be44fc2005-08-05 00:44:28 -0400836static void acpi_processor_power_verify_c3(struct acpi_processor *pr,
837 struct acpi_processor_cx *cx)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700838{
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400839 static int bm_check_flag;
840
Linus Torvalds1da177e2005-04-16 15:20:36 -0700841
842 if (!cx->address)
Patrick Mocheld550d982006-06-27 00:41:40 -0400843 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844
845 /*
846 * C3 latency must be less than or equal to 1000
847 * microseconds.
848 */
849 else if (cx->latency > ACPI_PROCESSOR_MAX_C3_LATENCY) {
850 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
Len Brown4be44fc2005-08-05 00:44:28 -0400851 "latency too large [%d]\n", cx->latency));
Patrick Mocheld550d982006-06-27 00:41:40 -0400852 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700853 }
854
Linus Torvalds1da177e2005-04-16 15:20:36 -0700855 /*
856 * PIIX4 Erratum #18: We don't support C3 when Type-F (fast)
857 * DMA transfers are used by any ISA device to avoid livelock.
858 * Note that we could disable Type-F DMA (as recommended by
859 * the erratum), but this is known to disrupt certain ISA
860 * devices thus we take the conservative approach.
861 */
862 else if (errata.piix4.fdma) {
863 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
Len Brown4be44fc2005-08-05 00:44:28 -0400864 "C3 not supported on PIIX4 with Type-F DMA\n"));
Patrick Mocheld550d982006-06-27 00:41:40 -0400865 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700866 }
867
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400868 /* All the logic here assumes flags.bm_check is same across all CPUs */
869 if (!bm_check_flag) {
870 /* Determine whether bm_check is needed based on CPU */
871 acpi_processor_power_init_bm_check(&(pr->flags), pr->id);
872 bm_check_flag = pr->flags.bm_check;
873 } else {
874 pr->flags.bm_check = bm_check_flag;
875 }
876
877 if (pr->flags.bm_check) {
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400878 /* bus mastering control is necessary */
879 if (!pr->flags.bm_control) {
880 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
Len Brown4be44fc2005-08-05 00:44:28 -0400881 "C3 support requires bus mastering control\n"));
Patrick Mocheld550d982006-06-27 00:41:40 -0400882 return;
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400883 }
884 } else {
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400885 /*
886 * WBINVD should be set in fadt, for C3 state to be
887 * supported on when bm_check is not required.
888 */
Alexey Starikovskiycee324b2007-02-02 19:48:22 +0300889 if (!(acpi_gbl_FADT.flags & ACPI_FADT_WBINVD)) {
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400890 ACPI_DEBUG_PRINT((ACPI_DB_INFO,
Len Brown4be44fc2005-08-05 00:44:28 -0400891 "Cache invalidation should work properly"
892 " for C3 to be enabled on SMP systems\n"));
Patrick Mocheld550d982006-06-27 00:41:40 -0400893 return;
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400894 }
Bob Moored8c71b62007-02-02 19:48:21 +0300895 acpi_set_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -0400896 }
897
Linus Torvalds1da177e2005-04-16 15:20:36 -0700898 /*
899 * Otherwise we've met all of our C3 requirements.
900 * Normalize the C3 latency to expidite policy. Enable
901 * checking of bus mastering status (bm_check) so we can
902 * use this in our C3 policy
903 */
904 cx->valid = 1;
905 cx->latency_ticks = US_TO_PM_TIMER_TICKS(cx->latency);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700906
Patrick Mocheld550d982006-06-27 00:41:40 -0400907 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908}
909
Linus Torvalds1da177e2005-04-16 15:20:36 -0700910static int acpi_processor_power_verify(struct acpi_processor *pr)
911{
912 unsigned int i;
913 unsigned int working = 0;
Venkatesh Pallipadi6eb0a0f2006-01-11 22:44:21 +0100914
Andi Kleenbd663342006-03-25 16:31:07 +0100915#ifdef ARCH_APICTIMER_STOPS_ON_C3
Andi Kleen0b5c59a2006-03-26 02:24:07 +0100916 int timer_broadcast = 0;
917 cpumask_t mask = cpumask_of_cpu(pr->id);
Andi Kleenbd663342006-03-25 16:31:07 +0100918 on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
Venkatesh Pallipadi6eb0a0f2006-01-11 22:44:21 +0100919#endif
920
Len Brown4be44fc2005-08-05 00:44:28 -0400921 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700922 struct acpi_processor_cx *cx = &pr->power.states[i];
923
924 switch (cx->type) {
925 case ACPI_STATE_C1:
926 cx->valid = 1;
927 break;
928
929 case ACPI_STATE_C2:
930 acpi_processor_power_verify_c2(cx);
Andi Kleenbd663342006-03-25 16:31:07 +0100931#ifdef ARCH_APICTIMER_STOPS_ON_C3
932 /* Some AMD systems fake C3 as C2, but still
933 have timer troubles */
934 if (cx->valid &&
935 boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
936 timer_broadcast++;
937#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700938 break;
939
940 case ACPI_STATE_C3:
941 acpi_processor_power_verify_c3(pr, cx);
Venkatesh Pallipadi6eb0a0f2006-01-11 22:44:21 +0100942#ifdef ARCH_APICTIMER_STOPS_ON_C3
Andi Kleenbd663342006-03-25 16:31:07 +0100943 if (cx->valid)
944 timer_broadcast++;
Venkatesh Pallipadi6eb0a0f2006-01-11 22:44:21 +0100945#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700946 break;
947 }
948
949 if (cx->valid)
950 working++;
951 }
952
Andi Kleen0b5c59a2006-03-26 02:24:07 +0100953#ifdef ARCH_APICTIMER_STOPS_ON_C3
Andi Kleenbd663342006-03-25 16:31:07 +0100954 if (timer_broadcast)
955 on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
Andi Kleen0b5c59a2006-03-26 02:24:07 +0100956#endif
Andi Kleenbd663342006-03-25 16:31:07 +0100957
Linus Torvalds1da177e2005-04-16 15:20:36 -0700958 return (working);
959}
960
Len Brown4be44fc2005-08-05 00:44:28 -0400961static int acpi_processor_get_power_info(struct acpi_processor *pr)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962{
963 unsigned int i;
964 int result;
965
Linus Torvalds1da177e2005-04-16 15:20:36 -0700966
967 /* NOTE: the idle thread may not be running while calling
968 * this function */
969
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700970 /* Zero initialize all the C-states info. */
971 memset(pr->power.states, 0, sizeof(pr->power.states));
972
Linus Torvalds1da177e2005-04-16 15:20:36 -0700973 result = acpi_processor_get_power_info_cst(pr);
Venkatesh Pallipadi6d93c642005-09-15 12:19:00 -0400974 if (result == -ENODEV)
Darrick J. Wongc5a114f2006-10-19 23:28:28 -0700975 result = acpi_processor_get_power_info_fadt(pr);
Venkatesh Pallipadi6d93c642005-09-15 12:19:00 -0400976
Venkatesh Pallipadi991528d2006-09-25 16:28:13 -0700977 if (result)
978 return result;
979
980 acpi_processor_get_power_info_default(pr);
981
Janosch Machowinskicf824782005-08-20 08:02:00 -0400982 pr->power.count = acpi_processor_power_verify(pr);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700983
984 /*
985 * Set Default Policy
986 * ------------------
987 * Now that we know which states are supported, set the default
988 * policy. Note that this policy can be changed dynamically
989 * (e.g. encourage deeper sleeps to conserve battery life when
990 * not on AC).
991 */
992 result = acpi_processor_set_power_policy(pr);
993 if (result)
Patrick Mocheld550d982006-06-27 00:41:40 -0400994 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700995
996 /*
997 * if one state of type C2 or C3 is available, mark this
998 * CPU as being "idle manageable"
999 */
1000 for (i = 1; i < ACPI_PROCESSOR_MAX_POWER; i++) {
Venkatesh Pallipadiacf05f42005-03-31 23:23:15 -05001001 if (pr->power.states[i].valid) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002 pr->power.count = i;
Linus Torvalds2203d6e2005-11-18 07:29:51 -08001003 if (pr->power.states[i].type >= ACPI_STATE_C2)
1004 pr->flags.power = 1;
Venkatesh Pallipadiacf05f42005-03-31 23:23:15 -05001005 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001006 }
1007
Patrick Mocheld550d982006-06-27 00:41:40 -04001008 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009}
1010
Len Brown4be44fc2005-08-05 00:44:28 -04001011int acpi_processor_cst_has_changed(struct acpi_processor *pr)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001012{
Len Brown4be44fc2005-08-05 00:44:28 -04001013 int result = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001014
Linus Torvalds1da177e2005-04-16 15:20:36 -07001015
1016 if (!pr)
Patrick Mocheld550d982006-06-27 00:41:40 -04001017 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001018
Len Brown4be44fc2005-08-05 00:44:28 -04001019 if (nocst) {
Patrick Mocheld550d982006-06-27 00:41:40 -04001020 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001021 }
1022
1023 if (!pr->flags.power_setup_done)
Patrick Mocheld550d982006-06-27 00:41:40 -04001024 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001025
1026 /* Fall back to the default idle loop */
1027 pm_idle = pm_idle_save;
Len Brown4be44fc2005-08-05 00:44:28 -04001028 synchronize_sched(); /* Relies on interrupts forcing exit from idle. */
Linus Torvalds1da177e2005-04-16 15:20:36 -07001029
1030 pr->flags.power = 0;
1031 result = acpi_processor_get_power_info(pr);
1032 if ((pr->flags.power == 1) && (pr->flags.power_setup_done))
1033 pm_idle = acpi_processor_idle;
1034
Patrick Mocheld550d982006-06-27 00:41:40 -04001035 return result;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001036}
1037
1038/* proc interface */
1039
1040static int acpi_processor_power_seq_show(struct seq_file *seq, void *offset)
1041{
Jan Engelhardt50dd0962006-10-01 00:28:50 +02001042 struct acpi_processor *pr = seq->private;
Len Brown4be44fc2005-08-05 00:44:28 -04001043 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001044
Linus Torvalds1da177e2005-04-16 15:20:36 -07001045
1046 if (!pr)
1047 goto end;
1048
1049 seq_printf(seq, "active state: C%zd\n"
Len Brown4be44fc2005-08-05 00:44:28 -04001050 "max_cstate: C%d\n"
Arjan van de Ven5c875792006-09-30 23:27:17 -07001051 "bus master activity: %08x\n"
1052 "maximum allowed latency: %d usec\n",
Len Brown4be44fc2005-08-05 00:44:28 -04001053 pr->power.state ? pr->power.state - pr->power.states : 0,
Arjan van de Ven5c875792006-09-30 23:27:17 -07001054 max_cstate, (unsigned)pr->power.bm_activity,
1055 system_latency_constraint());
Linus Torvalds1da177e2005-04-16 15:20:36 -07001056
1057 seq_puts(seq, "states:\n");
1058
1059 for (i = 1; i <= pr->power.count; i++) {
1060 seq_printf(seq, " %cC%d: ",
Len Brown4be44fc2005-08-05 00:44:28 -04001061 (&pr->power.states[i] ==
1062 pr->power.state ? '*' : ' '), i);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001063
1064 if (!pr->power.states[i].valid) {
1065 seq_puts(seq, "<not supported>\n");
1066 continue;
1067 }
1068
1069 switch (pr->power.states[i].type) {
1070 case ACPI_STATE_C1:
1071 seq_printf(seq, "type[C1] ");
1072 break;
1073 case ACPI_STATE_C2:
1074 seq_printf(seq, "type[C2] ");
1075 break;
1076 case ACPI_STATE_C3:
1077 seq_printf(seq, "type[C3] ");
1078 break;
1079 default:
1080 seq_printf(seq, "type[--] ");
1081 break;
1082 }
1083
1084 if (pr->power.states[i].promotion.state)
1085 seq_printf(seq, "promotion[C%zd] ",
Len Brown4be44fc2005-08-05 00:44:28 -04001086 (pr->power.states[i].promotion.state -
1087 pr->power.states));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001088 else
1089 seq_puts(seq, "promotion[--] ");
1090
1091 if (pr->power.states[i].demotion.state)
1092 seq_printf(seq, "demotion[C%zd] ",
Len Brown4be44fc2005-08-05 00:44:28 -04001093 (pr->power.states[i].demotion.state -
1094 pr->power.states));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095 else
1096 seq_puts(seq, "demotion[--] ");
1097
Dominik Brodowskia3c65982006-06-24 19:37:00 -04001098 seq_printf(seq, "latency[%03d] usage[%08d] duration[%020llu]\n",
Len Brown4be44fc2005-08-05 00:44:28 -04001099 pr->power.states[i].latency,
Dominik Brodowskia3c65982006-06-24 19:37:00 -04001100 pr->power.states[i].usage,
Alexey Starikovskiyb0b7eaa2007-01-25 22:39:44 -05001101 (unsigned long long)pr->power.states[i].time);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102 }
1103
Len Brown4be44fc2005-08-05 00:44:28 -04001104 end:
Patrick Mocheld550d982006-06-27 00:41:40 -04001105 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001106}
1107
1108static int acpi_processor_power_open_fs(struct inode *inode, struct file *file)
1109{
1110 return single_open(file, acpi_processor_power_seq_show,
Len Brown4be44fc2005-08-05 00:44:28 -04001111 PDE(inode)->data);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001112}
1113
Arjan van de Vend7508032006-07-04 13:06:00 -04001114static const struct file_operations acpi_processor_power_fops = {
Len Brown4be44fc2005-08-05 00:44:28 -04001115 .open = acpi_processor_power_open_fs,
1116 .read = seq_read,
1117 .llseek = seq_lseek,
1118 .release = single_release,
Linus Torvalds1da177e2005-04-16 15:20:36 -07001119};
1120
Andrew Morton1fec74a2006-10-17 00:09:58 -07001121#ifdef CONFIG_SMP
Arjan van de Ven5c875792006-09-30 23:27:17 -07001122static void smp_callback(void *v)
1123{
1124 /* we already woke the CPU up, nothing more to do */
1125}
1126
1127/*
1128 * This function gets called when a part of the kernel has a new latency
1129 * requirement. This means we need to get all processors out of their C-state,
1130 * and then recalculate a new suitable C-state. Just do a cross-cpu IPI; that
1131 * wakes them all right up.
1132 */
1133static int acpi_processor_latency_notify(struct notifier_block *b,
1134 unsigned long l, void *v)
1135{
1136 smp_call_function(smp_callback, NULL, 0, 1);
1137 return NOTIFY_OK;
1138}
1139
1140static struct notifier_block acpi_processor_latency_notifier = {
1141 .notifier_call = acpi_processor_latency_notify,
1142};
Andrew Morton1fec74a2006-10-17 00:09:58 -07001143#endif
Arjan van de Ven5c875792006-09-30 23:27:17 -07001144
Pierre Ossman7af8b662006-10-10 14:20:31 -07001145int __cpuinit acpi_processor_power_init(struct acpi_processor *pr,
Len Brown4be44fc2005-08-05 00:44:28 -04001146 struct acpi_device *device)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001147{
Len Brown4be44fc2005-08-05 00:44:28 -04001148 acpi_status status = 0;
Andreas Mohrb6835052006-04-27 05:25:00 -04001149 static int first_run;
Len Brown4be44fc2005-08-05 00:44:28 -04001150 struct proc_dir_entry *entry = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001151 unsigned int i;
1152
Linus Torvalds1da177e2005-04-16 15:20:36 -07001153
1154 if (!first_run) {
1155 dmi_check_system(processor_power_dmi_table);
1156 if (max_cstate < ACPI_C_STATES_MAX)
Len Brown4be44fc2005-08-05 00:44:28 -04001157 printk(KERN_NOTICE
1158 "ACPI: processor limited to max C-state %d\n",
1159 max_cstate);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001160 first_run++;
Andrew Morton1fec74a2006-10-17 00:09:58 -07001161#ifdef CONFIG_SMP
Arjan van de Ven5c875792006-09-30 23:27:17 -07001162 register_latency_notifier(&acpi_processor_latency_notifier);
Andrew Morton1fec74a2006-10-17 00:09:58 -07001163#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001164 }
1165
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -04001166 if (!pr)
Patrick Mocheld550d982006-06-27 00:41:40 -04001167 return -EINVAL;
Venkatesh Pallipadi02df8b92005-04-15 15:07:10 -04001168
Alexey Starikovskiycee324b2007-02-02 19:48:22 +03001169 if (acpi_gbl_FADT.cst_control && !nocst) {
Len Brown4be44fc2005-08-05 00:44:28 -04001170 status =
Alexey Starikovskiycee324b2007-02-02 19:48:22 +03001171 acpi_os_write_port(acpi_gbl_FADT.smi_command, acpi_gbl_FADT.cst_control, 8);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001172 if (ACPI_FAILURE(status)) {
Thomas Renningera6fc6722006-06-26 23:58:43 -04001173 ACPI_EXCEPTION((AE_INFO, status,
1174 "Notifying BIOS of _CST ability failed"));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001175 }
1176 }
1177
Linus Torvalds1da177e2005-04-16 15:20:36 -07001178 acpi_processor_get_power_info(pr);
1179
1180 /*
1181 * Install the idle handler if processor power management is supported.
1182 * Note that we use previously set idle handler will be used on
1183 * platforms that only support C1.
1184 */
1185 if ((pr->flags.power) && (!boot_option_idle_override)) {
1186 printk(KERN_INFO PREFIX "CPU%d (power states:", pr->id);
1187 for (i = 1; i <= pr->power.count; i++)
1188 if (pr->power.states[i].valid)
Len Brown4be44fc2005-08-05 00:44:28 -04001189 printk(" C%d[C%d]", i,
1190 pr->power.states[i].type);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001191 printk(")\n");
1192
1193 if (pr->id == 0) {
1194 pm_idle_save = pm_idle;
1195 pm_idle = acpi_processor_idle;
1196 }
1197 }
1198
1199 /* 'power' [R] */
1200 entry = create_proc_entry(ACPI_PROCESSOR_FILE_POWER,
Len Brown4be44fc2005-08-05 00:44:28 -04001201 S_IRUGO, acpi_device_dir(device));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202 if (!entry)
Thomas Renningera6fc6722006-06-26 23:58:43 -04001203 return -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001204 else {
1205 entry->proc_fops = &acpi_processor_power_fops;
1206 entry->data = acpi_driver_data(device);
1207 entry->owner = THIS_MODULE;
1208 }
1209
1210 pr->flags.power_setup_done = 1;
1211
Patrick Mocheld550d982006-06-27 00:41:40 -04001212 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001213}
1214
Len Brown4be44fc2005-08-05 00:44:28 -04001215int acpi_processor_power_exit(struct acpi_processor *pr,
1216 struct acpi_device *device)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001217{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001218
1219 pr->flags.power_setup_done = 0;
1220
1221 if (acpi_device_dir(device))
Len Brown4be44fc2005-08-05 00:44:28 -04001222 remove_proc_entry(ACPI_PROCESSOR_FILE_POWER,
1223 acpi_device_dir(device));
Linus Torvalds1da177e2005-04-16 15:20:36 -07001224
1225 /* Unregister the idle handler when processor #0 is removed. */
1226 if (pr->id == 0) {
1227 pm_idle = pm_idle_save;
1228
1229 /*
1230 * We are about to unload the current idle thread pm callback
1231 * (pm_idle), Wait for all processors to update cached/local
1232 * copies of pm_idle before proceeding.
1233 */
1234 cpu_idle_wait();
Andrew Morton1fec74a2006-10-17 00:09:58 -07001235#ifdef CONFIG_SMP
Arjan van de Ven5c875792006-09-30 23:27:17 -07001236 unregister_latency_notifier(&acpi_processor_latency_notifier);
Andrew Morton1fec74a2006-10-17 00:09:58 -07001237#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -07001238 }
1239
Patrick Mocheld550d982006-06-27 00:41:40 -04001240 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001241}