blob: e8726177d103082021a6549d4ce32d161e2bab2a [file] [log] [blame]
Len Brown26717172010-03-08 14:07:30 -05001/*
2 * intel_idle.c - native hardware idle loop for modern Intel processors
3 *
4 * Copyright (c) 2010, Intel Corporation.
5 * Len Brown <len.brown@intel.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * more details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21/*
22 * intel_idle is a cpuidle driver that loads on specific Intel processors
23 * in lieu of the legacy ACPI processor_idle driver. The intent is to
24 * make Linux more efficient on these processors, as intel_idle knows
25 * more than ACPI, as well as make Linux more immune to ACPI BIOS bugs.
26 */
27
28/*
29 * Design Assumptions
30 *
31 * All CPUs have same idle states as boot CPU
32 *
33 * Chipset BM_STS (bus master status) bit is a NOP
34 * for preventing entry into deep C-stats
35 */
36
37/*
38 * Known limitations
39 *
40 * The driver currently initializes for_each_online_cpu() upon modprobe.
41 * It it unaware of subsequent processors hot-added to the system.
42 * This means that if you boot with maxcpus=n and later online
43 * processors above n, those processors will use C1 only.
44 *
45 * ACPI has a .suspend hack to turn off deep c-statees during suspend
46 * to avoid complications with the lapic timer workaround.
47 * Have not seen issues with suspend, but may need same workaround here.
48 *
49 * There is currently no kernel-based automatic probing/loading mechanism
50 * if the driver is built as a module.
51 */
52
53/* un-comment DEBUG to enable pr_debug() statements */
54#define DEBUG
55
56#include <linux/kernel.h>
57#include <linux/cpuidle.h>
58#include <linux/clockchips.h>
59#include <linux/hrtimer.h> /* ktime_get_real() */
60#include <trace/events/power.h>
61#include <linux/sched.h>
Shaohua Li2a2d31c2011-01-10 09:38:12 +080062#include <linux/notifier.h>
63#include <linux/cpu.h>
Paul Gortmaker7c52d552011-05-27 12:33:10 -040064#include <linux/module.h>
Andi Kleenb66b8b92012-01-26 00:09:07 +010065#include <asm/cpu_device_id.h>
H. Peter Anvinbc83ccc2010-09-17 15:36:40 -070066#include <asm/mwait.h>
Len Brown14796fc2011-01-18 20:48:27 -050067#include <asm/msr.h>
Len Brown26717172010-03-08 14:07:30 -050068
69#define INTEL_IDLE_VERSION "0.4"
70#define PREFIX "intel_idle: "
71
Len Brown26717172010-03-08 14:07:30 -050072static struct cpuidle_driver intel_idle_driver = {
73 .name = "intel_idle",
74 .owner = THIS_MODULE,
75};
76/* intel_idle.max_cstate=0 disables driver */
77static int max_cstate = MWAIT_MAX_NUM_CSTATES - 1;
Len Brown26717172010-03-08 14:07:30 -050078
Len Brownc4236282010-05-28 02:22:03 -040079static unsigned int mwait_substates;
Len Brown26717172010-03-08 14:07:30 -050080
Shaohua Li2a2d31c2011-01-10 09:38:12 +080081#define LAPIC_TIMER_ALWAYS_RELIABLE 0xFFFFFFFF
Len Brown26717172010-03-08 14:07:30 -050082/* Reliable LAPIC Timer States, bit 1 for C1 etc. */
Len Brownd13780d2010-07-07 00:12:03 -040083static unsigned int lapic_timer_reliable_states = (1 << 1); /* Default to only C1 */
Len Brown26717172010-03-08 14:07:30 -050084
Andi Kleenb66b8b92012-01-26 00:09:07 +010085struct idle_cpu {
86 struct cpuidle_state *state_table;
87
88 /*
89 * Hardware C-state auto-demotion may not always be optimal.
90 * Indicate which enable bits to clear here.
91 */
92 unsigned long auto_demotion_disable_flags;
93};
94
95static const struct idle_cpu *icpu;
Namhyung Kim3265eba2010-08-08 03:10:03 +090096static struct cpuidle_device __percpu *intel_idle_cpuidle_devices;
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +053097static int intel_idle(struct cpuidle_device *dev,
98 struct cpuidle_driver *drv, int index);
Daniel Lezcano25ac7762012-07-05 15:23:25 +020099static int intel_idle_cpu_init(int cpu);
Len Brown26717172010-03-08 14:07:30 -0500100
101static struct cpuidle_state *cpuidle_state_table;
102
103/*
Len Brown956d0332011-01-12 02:51:20 -0500104 * Set this flag for states where the HW flushes the TLB for us
105 * and so we don't need cross-calls to keep it consistent.
106 * If this flag is set, SW flushes the TLB, so even if the
107 * HW doesn't do the flushing, this flag is safe to use.
108 */
109#define CPUIDLE_FLAG_TLB_FLUSHED 0x10000
110
111/*
Len Brown26717172010-03-08 14:07:30 -0500112 * States are indexed by the cstate number,
113 * which is also the index into the MWAIT hint array.
114 * Thus C0 is a dummy.
115 */
116static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = {
117 { /* MWAIT C0 */ },
118 { /* MWAIT C1 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100119 .name = "C1-NHM",
Len Brown26717172010-03-08 14:07:30 -0500120 .desc = "MWAIT 0x00",
Len Brown26717172010-03-08 14:07:30 -0500121 .flags = CPUIDLE_FLAG_TIME_VALID,
122 .exit_latency = 3,
Len Brown26717172010-03-08 14:07:30 -0500123 .target_residency = 6,
124 .enter = &intel_idle },
125 { /* MWAIT C2 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100126 .name = "C3-NHM",
Len Brown26717172010-03-08 14:07:30 -0500127 .desc = "MWAIT 0x10",
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400128 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown26717172010-03-08 14:07:30 -0500129 .exit_latency = 20,
Len Brown26717172010-03-08 14:07:30 -0500130 .target_residency = 80,
131 .enter = &intel_idle },
132 { /* MWAIT C3 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100133 .name = "C6-NHM",
Len Brown26717172010-03-08 14:07:30 -0500134 .desc = "MWAIT 0x20",
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400135 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown26717172010-03-08 14:07:30 -0500136 .exit_latency = 200,
Len Brown26717172010-03-08 14:07:30 -0500137 .target_residency = 800,
138 .enter = &intel_idle },
139};
140
Len Brownd13780d2010-07-07 00:12:03 -0400141static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = {
142 { /* MWAIT C0 */ },
143 { /* MWAIT C1 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100144 .name = "C1-SNB",
Len Brownd13780d2010-07-07 00:12:03 -0400145 .desc = "MWAIT 0x00",
Len Brownd13780d2010-07-07 00:12:03 -0400146 .flags = CPUIDLE_FLAG_TIME_VALID,
147 .exit_latency = 1,
Len Brownddbd5502010-12-13 18:28:22 -0500148 .target_residency = 1,
Len Brownd13780d2010-07-07 00:12:03 -0400149 .enter = &intel_idle },
150 { /* MWAIT C2 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100151 .name = "C3-SNB",
Len Brownd13780d2010-07-07 00:12:03 -0400152 .desc = "MWAIT 0x10",
Len Brown00527cc2010-10-23 02:33:50 -0400153 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brownd13780d2010-07-07 00:12:03 -0400154 .exit_latency = 80,
Len Brownddbd5502010-12-13 18:28:22 -0500155 .target_residency = 211,
Len Brownd13780d2010-07-07 00:12:03 -0400156 .enter = &intel_idle },
157 { /* MWAIT C3 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100158 .name = "C6-SNB",
Len Brownd13780d2010-07-07 00:12:03 -0400159 .desc = "MWAIT 0x20",
Len Brown00527cc2010-10-23 02:33:50 -0400160 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brownd13780d2010-07-07 00:12:03 -0400161 .exit_latency = 104,
Len Brownddbd5502010-12-13 18:28:22 -0500162 .target_residency = 345,
Len Brownd13780d2010-07-07 00:12:03 -0400163 .enter = &intel_idle },
164 { /* MWAIT C4 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100165 .name = "C7-SNB",
Len Brownd13780d2010-07-07 00:12:03 -0400166 .desc = "MWAIT 0x30",
Len Brown00527cc2010-10-23 02:33:50 -0400167 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brownd13780d2010-07-07 00:12:03 -0400168 .exit_latency = 109,
Len Brownddbd5502010-12-13 18:28:22 -0500169 .target_residency = 345,
Len Brownd13780d2010-07-07 00:12:03 -0400170 .enter = &intel_idle },
171};
172
Len Brown6edab082012-06-01 19:45:32 -0400173static struct cpuidle_state ivb_cstates[MWAIT_MAX_NUM_CSTATES] = {
174 { /* MWAIT C0 */ },
175 { /* MWAIT C1 */
176 .name = "C1-IVB",
177 .desc = "MWAIT 0x00",
178 .flags = CPUIDLE_FLAG_TIME_VALID,
179 .exit_latency = 1,
180 .target_residency = 1,
181 .enter = &intel_idle },
182 { /* MWAIT C2 */
183 .name = "C3-IVB",
184 .desc = "MWAIT 0x10",
185 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
186 .exit_latency = 59,
187 .target_residency = 156,
188 .enter = &intel_idle },
189 { /* MWAIT C3 */
190 .name = "C6-IVB",
191 .desc = "MWAIT 0x20",
192 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
193 .exit_latency = 80,
194 .target_residency = 300,
195 .enter = &intel_idle },
196 { /* MWAIT C4 */
197 .name = "C7-IVB",
198 .desc = "MWAIT 0x30",
199 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
200 .exit_latency = 87,
201 .target_residency = 300,
202 .enter = &intel_idle },
203};
204
Len Brown26717172010-03-08 14:07:30 -0500205static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = {
206 { /* MWAIT C0 */ },
207 { /* MWAIT C1 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100208 .name = "C1-ATM",
Len Brown26717172010-03-08 14:07:30 -0500209 .desc = "MWAIT 0x00",
Len Brown26717172010-03-08 14:07:30 -0500210 .flags = CPUIDLE_FLAG_TIME_VALID,
211 .exit_latency = 1,
Len Brown26717172010-03-08 14:07:30 -0500212 .target_residency = 4,
213 .enter = &intel_idle },
214 { /* MWAIT C2 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100215 .name = "C2-ATM",
Len Brown26717172010-03-08 14:07:30 -0500216 .desc = "MWAIT 0x10",
Len Brown26717172010-03-08 14:07:30 -0500217 .flags = CPUIDLE_FLAG_TIME_VALID,
218 .exit_latency = 20,
Len Brown26717172010-03-08 14:07:30 -0500219 .target_residency = 80,
220 .enter = &intel_idle },
221 { /* MWAIT C3 */ },
222 { /* MWAIT C4 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100223 .name = "C4-ATM",
Len Brown26717172010-03-08 14:07:30 -0500224 .desc = "MWAIT 0x30",
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400225 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown26717172010-03-08 14:07:30 -0500226 .exit_latency = 100,
Len Brown26717172010-03-08 14:07:30 -0500227 .target_residency = 400,
228 .enter = &intel_idle },
229 { /* MWAIT C5 */ },
230 { /* MWAIT C6 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100231 .name = "C6-ATM",
Len Brown7fcca7d2010-10-05 13:43:14 -0400232 .desc = "MWAIT 0x52",
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400233 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown7fcca7d2010-10-05 13:43:14 -0400234 .exit_latency = 140,
Len Brown7fcca7d2010-10-05 13:43:14 -0400235 .target_residency = 560,
236 .enter = &intel_idle },
Len Brown26717172010-03-08 14:07:30 -0500237};
238
David Howells95e3ec12011-12-15 13:03:14 +0000239static long get_driver_data(int cstate)
Deepthi Dharwar42027352011-10-28 16:20:33 +0530240{
241 int driver_data;
242 switch (cstate) {
243
244 case 1: /* MWAIT C1 */
245 driver_data = 0x00;
246 break;
247 case 2: /* MWAIT C2 */
248 driver_data = 0x10;
249 break;
250 case 3: /* MWAIT C3 */
251 driver_data = 0x20;
252 break;
253 case 4: /* MWAIT C4 */
254 driver_data = 0x30;
255 break;
256 case 5: /* MWAIT C5 */
257 driver_data = 0x40;
258 break;
259 case 6: /* MWAIT C6 */
260 driver_data = 0x52;
261 break;
262 default:
263 driver_data = 0x00;
264 }
265 return driver_data;
266}
267
Len Brown26717172010-03-08 14:07:30 -0500268/**
269 * intel_idle
270 * @dev: cpuidle_device
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530271 * @drv: cpuidle driver
Deepthi Dharware978aa72011-10-28 16:20:09 +0530272 * @index: index of cpuidle state
Len Brown26717172010-03-08 14:07:30 -0500273 *
Yanmin Zhang63ff07b2012-01-10 15:48:21 -0800274 * Must be called under local_irq_disable().
Len Brown26717172010-03-08 14:07:30 -0500275 */
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530276static int intel_idle(struct cpuidle_device *dev,
277 struct cpuidle_driver *drv, int index)
Len Brown26717172010-03-08 14:07:30 -0500278{
279 unsigned long ecx = 1; /* break on interrupt flag */
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530280 struct cpuidle_state *state = &drv->states[index];
Deepthi Dharwar42027352011-10-28 16:20:33 +0530281 struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
282 unsigned long eax = (unsigned long)cpuidle_get_statedata(state_usage);
Len Brown26717172010-03-08 14:07:30 -0500283 unsigned int cstate;
284 ktime_t kt_before, kt_after;
285 s64 usec_delta;
286 int cpu = smp_processor_id();
287
288 cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1;
289
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400290 /*
Len Brownc8381cc2010-10-15 20:43:06 -0400291 * leave_mm() to avoid costly and often unnecessary wakeups
292 * for flushing the user TLB's associated with the active mm.
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400293 */
Len Brownc8381cc2010-10-15 20:43:06 -0400294 if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400295 leave_mm(cpu);
296
Len Brown26717172010-03-08 14:07:30 -0500297 if (!(lapic_timer_reliable_states & (1 << (cstate))))
298 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
299
300 kt_before = ktime_get_real();
301
302 stop_critical_timings();
Len Brown26717172010-03-08 14:07:30 -0500303 if (!need_resched()) {
304
305 __monitor((void *)&current_thread_info()->flags, 0, 0);
306 smp_mb();
307 if (!need_resched())
308 __mwait(eax, ecx);
309 }
310
311 start_critical_timings();
312
313 kt_after = ktime_get_real();
314 usec_delta = ktime_to_us(ktime_sub(kt_after, kt_before));
315
316 local_irq_enable();
317
318 if (!(lapic_timer_reliable_states & (1 << (cstate))))
319 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
320
Deepthi Dharware978aa72011-10-28 16:20:09 +0530321 /* Update cpuidle counters */
322 dev->last_residency = (int)usec_delta;
323
324 return index;
Len Brown26717172010-03-08 14:07:30 -0500325}
326
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800327static void __setup_broadcast_timer(void *arg)
328{
329 unsigned long reason = (unsigned long)arg;
330 int cpu = smp_processor_id();
331
332 reason = reason ?
333 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
334
335 clockevents_notify(reason, &cpu);
336}
337
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200338static int cpu_hotplug_notify(struct notifier_block *n,
339 unsigned long action, void *hcpu)
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800340{
341 int hotcpu = (unsigned long)hcpu;
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200342 struct cpuidle_device *dev;
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800343
344 switch (action & 0xf) {
345 case CPU_ONLINE:
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200346
347 if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
348 smp_call_function_single(hotcpu, __setup_broadcast_timer,
349 (void *)true, 1);
350
351 /*
352 * Some systems can hotplug a cpu at runtime after
353 * the kernel has booted, we have to initialize the
354 * driver in this case
355 */
356 dev = per_cpu_ptr(intel_idle_cpuidle_devices, hotcpu);
357 if (!dev->registered)
358 intel_idle_cpu_init(hotcpu);
359
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800360 break;
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800361 }
362 return NOTIFY_OK;
363}
364
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200365static struct notifier_block cpu_hotplug_notifier = {
366 .notifier_call = cpu_hotplug_notify,
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800367};
368
Len Brown14796fc2011-01-18 20:48:27 -0500369static void auto_demotion_disable(void *dummy)
370{
371 unsigned long long msr_bits;
372
373 rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
Andi Kleenb66b8b92012-01-26 00:09:07 +0100374 msr_bits &= ~(icpu->auto_demotion_disable_flags);
Len Brown14796fc2011-01-18 20:48:27 -0500375 wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
376}
377
Andi Kleenb66b8b92012-01-26 00:09:07 +0100378static const struct idle_cpu idle_cpu_nehalem = {
379 .state_table = nehalem_cstates,
Andi Kleenb66b8b92012-01-26 00:09:07 +0100380 .auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
381};
382
383static const struct idle_cpu idle_cpu_atom = {
384 .state_table = atom_cstates,
385};
386
387static const struct idle_cpu idle_cpu_lincroft = {
388 .state_table = atom_cstates,
389 .auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
390};
391
392static const struct idle_cpu idle_cpu_snb = {
393 .state_table = snb_cstates,
394};
395
Len Brown6edab082012-06-01 19:45:32 -0400396static const struct idle_cpu idle_cpu_ivb = {
397 .state_table = ivb_cstates,
398};
399
Andi Kleenb66b8b92012-01-26 00:09:07 +0100400#define ICPU(model, cpu) \
401 { X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
402
403static const struct x86_cpu_id intel_idle_ids[] = {
404 ICPU(0x1a, idle_cpu_nehalem),
405 ICPU(0x1e, idle_cpu_nehalem),
406 ICPU(0x1f, idle_cpu_nehalem),
Ben Hutchings8bf11932012-02-16 04:13:14 +0000407 ICPU(0x25, idle_cpu_nehalem),
408 ICPU(0x2c, idle_cpu_nehalem),
409 ICPU(0x2e, idle_cpu_nehalem),
Andi Kleenb66b8b92012-01-26 00:09:07 +0100410 ICPU(0x1c, idle_cpu_atom),
411 ICPU(0x26, idle_cpu_lincroft),
Ben Hutchings8bf11932012-02-16 04:13:14 +0000412 ICPU(0x2f, idle_cpu_nehalem),
Andi Kleenb66b8b92012-01-26 00:09:07 +0100413 ICPU(0x2a, idle_cpu_snb),
414 ICPU(0x2d, idle_cpu_snb),
Len Brown6edab082012-06-01 19:45:32 -0400415 ICPU(0x3a, idle_cpu_ivb),
Andi Kleenb66b8b92012-01-26 00:09:07 +0100416 {}
417};
418MODULE_DEVICE_TABLE(x86cpu, intel_idle_ids);
419
Len Brown26717172010-03-08 14:07:30 -0500420/*
421 * intel_idle_probe()
422 */
423static int intel_idle_probe(void)
424{
Len Brownc4236282010-05-28 02:22:03 -0400425 unsigned int eax, ebx, ecx;
Andi Kleenb66b8b92012-01-26 00:09:07 +0100426 const struct x86_cpu_id *id;
Len Brown26717172010-03-08 14:07:30 -0500427
428 if (max_cstate == 0) {
429 pr_debug(PREFIX "disabled\n");
430 return -EPERM;
431 }
432
Andi Kleenb66b8b92012-01-26 00:09:07 +0100433 id = x86_match_cpu(intel_idle_ids);
434 if (!id) {
435 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
436 boot_cpu_data.x86 == 6)
437 pr_debug(PREFIX "does not run on family %d model %d\n",
438 boot_cpu_data.x86, boot_cpu_data.x86_model);
Len Brown26717172010-03-08 14:07:30 -0500439 return -ENODEV;
Andi Kleenb66b8b92012-01-26 00:09:07 +0100440 }
Len Brown26717172010-03-08 14:07:30 -0500441
442 if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
443 return -ENODEV;
444
Len Brownc4236282010-05-28 02:22:03 -0400445 cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
Len Brown26717172010-03-08 14:07:30 -0500446
447 if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
Thomas Renninger5c2a9f02011-12-04 22:17:29 +0100448 !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
449 !mwait_substates)
Len Brown26717172010-03-08 14:07:30 -0500450 return -ENODEV;
Len Brown26717172010-03-08 14:07:30 -0500451
Len Brownc4236282010-05-28 02:22:03 -0400452 pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates);
Len Brown26717172010-03-08 14:07:30 -0500453
Andi Kleenb66b8b92012-01-26 00:09:07 +0100454 icpu = (const struct idle_cpu *)id->driver_data;
455 cpuidle_state_table = icpu->state_table;
Len Brown26717172010-03-08 14:07:30 -0500456
Len Brown56b9aea2010-12-02 01:19:32 -0500457 if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800458 lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200459 else
Shaohua Li39a74fd2012-01-10 15:48:19 -0800460 on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200461
462 register_cpu_notifier(&cpu_hotplug_notifier);
Len Brown56b9aea2010-12-02 01:19:32 -0500463
Len Brown26717172010-03-08 14:07:30 -0500464 pr_debug(PREFIX "v" INTEL_IDLE_VERSION
465 " model 0x%X\n", boot_cpu_data.x86_model);
466
467 pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n",
468 lapic_timer_reliable_states);
469 return 0;
470}
471
472/*
473 * intel_idle_cpuidle_devices_uninit()
474 * unregister, free cpuidle_devices
475 */
476static void intel_idle_cpuidle_devices_uninit(void)
477{
478 int i;
479 struct cpuidle_device *dev;
480
481 for_each_online_cpu(i) {
482 dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
483 cpuidle_unregister_device(dev);
484 }
485
486 free_percpu(intel_idle_cpuidle_devices);
487 return;
488}
489/*
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530490 * intel_idle_cpuidle_driver_init()
491 * allocate, initialize cpuidle_states
492 */
493static int intel_idle_cpuidle_driver_init(void)
494{
495 int cstate;
496 struct cpuidle_driver *drv = &intel_idle_driver;
497
498 drv->state_count = 1;
499
500 for (cstate = 1; cstate < MWAIT_MAX_NUM_CSTATES; ++cstate) {
501 int num_substates;
502
503 if (cstate > max_cstate) {
504 printk(PREFIX "max_cstate %d reached\n",
505 max_cstate);
506 break;
507 }
508
509 /* does the state exist in CPUID.MWAIT? */
510 num_substates = (mwait_substates >> ((cstate) * 4))
511 & MWAIT_SUBSTATE_MASK;
512 if (num_substates == 0)
513 continue;
514 /* is the state not enabled? */
515 if (cpuidle_state_table[cstate].enter == NULL) {
516 /* does the driver not know about the state? */
517 if (*cpuidle_state_table[cstate].name == '\0')
518 pr_debug(PREFIX "unaware of model 0x%x"
519 " MWAIT %d please"
520 " contact lenb@kernel.org",
521 boot_cpu_data.x86_model, cstate);
522 continue;
523 }
524
525 if ((cstate > 2) &&
526 !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
527 mark_tsc_unstable("TSC halts in idle"
528 " states deeper than C2");
529
530 drv->states[drv->state_count] = /* structure copy */
531 cpuidle_state_table[cstate];
532
533 drv->state_count += 1;
534 }
535
Andi Kleenb66b8b92012-01-26 00:09:07 +0100536 if (icpu->auto_demotion_disable_flags)
Shaohua Li39a74fd2012-01-10 15:48:19 -0800537 on_each_cpu(auto_demotion_disable, NULL, 1);
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530538
539 return 0;
540}
541
542
543/*
Thomas Renninger65b7f832012-01-17 22:40:08 +0100544 * intel_idle_cpu_init()
Len Brown26717172010-03-08 14:07:30 -0500545 * allocate, initialize, register cpuidle_devices
Thomas Renninger65b7f832012-01-17 22:40:08 +0100546 * @cpu: cpu/core to initialize
Len Brown26717172010-03-08 14:07:30 -0500547 */
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200548static int intel_idle_cpu_init(int cpu)
Len Brown26717172010-03-08 14:07:30 -0500549{
Thomas Renninger65b7f832012-01-17 22:40:08 +0100550 int cstate;
Len Brown26717172010-03-08 14:07:30 -0500551 struct cpuidle_device *dev;
552
Thomas Renninger65b7f832012-01-17 22:40:08 +0100553 dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
Len Brown26717172010-03-08 14:07:30 -0500554
Thomas Renninger65b7f832012-01-17 22:40:08 +0100555 dev->state_count = 1;
Len Brown26717172010-03-08 14:07:30 -0500556
Thomas Renninger65b7f832012-01-17 22:40:08 +0100557 for (cstate = 1; cstate < MWAIT_MAX_NUM_CSTATES; ++cstate) {
558 int num_substates;
Len Brown26717172010-03-08 14:07:30 -0500559
Thomas Renninger65b7f832012-01-17 22:40:08 +0100560 if (cstate > max_cstate) {
Marcos Paulo de Souzadc716e92012-03-21 16:33:43 -0700561 printk(PREFIX "max_cstate %d reached\n", max_cstate);
Thomas Renninger65b7f832012-01-17 22:40:08 +0100562 break;
563 }
Len Brown26717172010-03-08 14:07:30 -0500564
Thomas Renninger65b7f832012-01-17 22:40:08 +0100565 /* does the state exist in CPUID.MWAIT? */
566 num_substates = (mwait_substates >> ((cstate) * 4))
567 & MWAIT_SUBSTATE_MASK;
568 if (num_substates == 0)
569 continue;
570 /* is the state not enabled? */
571 if (cpuidle_state_table[cstate].enter == NULL)
572 continue;
Len Brown26717172010-03-08 14:07:30 -0500573
Thomas Renninger65b7f832012-01-17 22:40:08 +0100574 dev->states_usage[dev->state_count].driver_data =
575 (void *)get_driver_data(cstate);
Len Brown26717172010-03-08 14:07:30 -0500576
Marcos Paulo de Souzadc716e92012-03-21 16:33:43 -0700577 dev->state_count += 1;
578 }
579
Thomas Renninger65b7f832012-01-17 22:40:08 +0100580 dev->cpu = cpu;
Len Brown26717172010-03-08 14:07:30 -0500581
Thomas Renninger65b7f832012-01-17 22:40:08 +0100582 if (cpuidle_register_device(dev)) {
583 pr_debug(PREFIX "cpuidle_register_device %d failed!\n", cpu);
584 intel_idle_cpuidle_devices_uninit();
585 return -EIO;
Len Brown26717172010-03-08 14:07:30 -0500586 }
587
Andi Kleenb66b8b92012-01-26 00:09:07 +0100588 if (icpu->auto_demotion_disable_flags)
Thomas Renninger65b7f832012-01-17 22:40:08 +0100589 smp_call_function_single(cpu, auto_demotion_disable, NULL, 1);
590
Len Brown26717172010-03-08 14:07:30 -0500591 return 0;
592}
Len Brown26717172010-03-08 14:07:30 -0500593
594static int __init intel_idle_init(void)
595{
Thomas Renninger65b7f832012-01-17 22:40:08 +0100596 int retval, i;
Len Brown26717172010-03-08 14:07:30 -0500597
Thomas Renningerd1896042010-11-03 17:06:14 +0100598 /* Do not load intel_idle at all for now if idle= is passed */
599 if (boot_option_idle_override != IDLE_NO_OVERRIDE)
600 return -ENODEV;
601
Len Brown26717172010-03-08 14:07:30 -0500602 retval = intel_idle_probe();
603 if (retval)
604 return retval;
605
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530606 intel_idle_cpuidle_driver_init();
Len Brown26717172010-03-08 14:07:30 -0500607 retval = cpuidle_register_driver(&intel_idle_driver);
608 if (retval) {
Konrad Rzeszutek Wilk3735d522012-08-16 22:06:55 +0200609 struct cpuidle_driver *drv = cpuidle_get_driver();
Len Brown26717172010-03-08 14:07:30 -0500610 printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
Konrad Rzeszutek Wilk3735d522012-08-16 22:06:55 +0200611 drv ? drv->name : "none");
Len Brown26717172010-03-08 14:07:30 -0500612 return retval;
613 }
614
Thomas Renninger65b7f832012-01-17 22:40:08 +0100615 intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
616 if (intel_idle_cpuidle_devices == NULL)
617 return -ENOMEM;
618
619 for_each_online_cpu(i) {
620 retval = intel_idle_cpu_init(i);
621 if (retval) {
622 cpuidle_unregister_driver(&intel_idle_driver);
623 return retval;
624 }
Len Brown26717172010-03-08 14:07:30 -0500625 }
626
627 return 0;
628}
629
630static void __exit intel_idle_exit(void)
631{
632 intel_idle_cpuidle_devices_uninit();
633 cpuidle_unregister_driver(&intel_idle_driver);
634
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200635
636 if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
Shaohua Li39a74fd2012-01-10 15:48:19 -0800637 on_each_cpu(__setup_broadcast_timer, (void *)false, 1);
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200638 unregister_cpu_notifier(&cpu_hotplug_notifier);
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800639
Len Brown26717172010-03-08 14:07:30 -0500640 return;
641}
642
643module_init(intel_idle_init);
644module_exit(intel_idle_exit);
645
Len Brown26717172010-03-08 14:07:30 -0500646module_param(max_cstate, int, 0444);
Len Brown26717172010-03-08 14:07:30 -0500647
648MODULE_AUTHOR("Len Brown <len.brown@intel.com>");
649MODULE_DESCRIPTION("Cpuidle driver for Intel Hardware v" INTEL_IDLE_VERSION);
650MODULE_LICENSE("GPL");