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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 Brown26717172010-03-08 14:07:30 -0500173static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = {
174 { /* MWAIT C0 */ },
175 { /* MWAIT C1 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100176 .name = "C1-ATM",
Len Brown26717172010-03-08 14:07:30 -0500177 .desc = "MWAIT 0x00",
Len Brown26717172010-03-08 14:07:30 -0500178 .flags = CPUIDLE_FLAG_TIME_VALID,
179 .exit_latency = 1,
Len Brown26717172010-03-08 14:07:30 -0500180 .target_residency = 4,
181 .enter = &intel_idle },
182 { /* MWAIT C2 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100183 .name = "C2-ATM",
Len Brown26717172010-03-08 14:07:30 -0500184 .desc = "MWAIT 0x10",
Len Brown26717172010-03-08 14:07:30 -0500185 .flags = CPUIDLE_FLAG_TIME_VALID,
186 .exit_latency = 20,
Len Brown26717172010-03-08 14:07:30 -0500187 .target_residency = 80,
188 .enter = &intel_idle },
189 { /* MWAIT C3 */ },
190 { /* MWAIT C4 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100191 .name = "C4-ATM",
Len Brown26717172010-03-08 14:07:30 -0500192 .desc = "MWAIT 0x30",
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400193 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown26717172010-03-08 14:07:30 -0500194 .exit_latency = 100,
Len Brown26717172010-03-08 14:07:30 -0500195 .target_residency = 400,
196 .enter = &intel_idle },
197 { /* MWAIT C5 */ },
198 { /* MWAIT C6 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100199 .name = "C6-ATM",
Len Brown7fcca7d2010-10-05 13:43:14 -0400200 .desc = "MWAIT 0x52",
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400201 .flags = CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown7fcca7d2010-10-05 13:43:14 -0400202 .exit_latency = 140,
Len Brown7fcca7d2010-10-05 13:43:14 -0400203 .target_residency = 560,
204 .enter = &intel_idle },
Len Brown26717172010-03-08 14:07:30 -0500205};
206
David Howells95e3ec12011-12-15 13:03:14 +0000207static long get_driver_data(int cstate)
Deepthi Dharwar42027352011-10-28 16:20:33 +0530208{
209 int driver_data;
210 switch (cstate) {
211
212 case 1: /* MWAIT C1 */
213 driver_data = 0x00;
214 break;
215 case 2: /* MWAIT C2 */
216 driver_data = 0x10;
217 break;
218 case 3: /* MWAIT C3 */
219 driver_data = 0x20;
220 break;
221 case 4: /* MWAIT C4 */
222 driver_data = 0x30;
223 break;
224 case 5: /* MWAIT C5 */
225 driver_data = 0x40;
226 break;
227 case 6: /* MWAIT C6 */
228 driver_data = 0x52;
229 break;
230 default:
231 driver_data = 0x00;
232 }
233 return driver_data;
234}
235
Len Brown26717172010-03-08 14:07:30 -0500236/**
237 * intel_idle
238 * @dev: cpuidle_device
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530239 * @drv: cpuidle driver
Deepthi Dharware978aa72011-10-28 16:20:09 +0530240 * @index: index of cpuidle state
Len Brown26717172010-03-08 14:07:30 -0500241 *
Yanmin Zhang63ff07b2012-01-10 15:48:21 -0800242 * Must be called under local_irq_disable().
Len Brown26717172010-03-08 14:07:30 -0500243 */
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530244static int intel_idle(struct cpuidle_device *dev,
245 struct cpuidle_driver *drv, int index)
Len Brown26717172010-03-08 14:07:30 -0500246{
247 unsigned long ecx = 1; /* break on interrupt flag */
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530248 struct cpuidle_state *state = &drv->states[index];
Deepthi Dharwar42027352011-10-28 16:20:33 +0530249 struct cpuidle_state_usage *state_usage = &dev->states_usage[index];
250 unsigned long eax = (unsigned long)cpuidle_get_statedata(state_usage);
Len Brown26717172010-03-08 14:07:30 -0500251 unsigned int cstate;
252 ktime_t kt_before, kt_after;
253 s64 usec_delta;
254 int cpu = smp_processor_id();
255
256 cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1;
257
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400258 /*
Len Brownc8381cc2010-10-15 20:43:06 -0400259 * leave_mm() to avoid costly and often unnecessary wakeups
260 * for flushing the user TLB's associated with the active mm.
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400261 */
Len Brownc8381cc2010-10-15 20:43:06 -0400262 if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400263 leave_mm(cpu);
264
Len Brown26717172010-03-08 14:07:30 -0500265 if (!(lapic_timer_reliable_states & (1 << (cstate))))
266 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
267
268 kt_before = ktime_get_real();
269
270 stop_critical_timings();
Len Brown26717172010-03-08 14:07:30 -0500271 if (!need_resched()) {
272
273 __monitor((void *)&current_thread_info()->flags, 0, 0);
274 smp_mb();
275 if (!need_resched())
276 __mwait(eax, ecx);
277 }
278
279 start_critical_timings();
280
281 kt_after = ktime_get_real();
282 usec_delta = ktime_to_us(ktime_sub(kt_after, kt_before));
283
284 local_irq_enable();
285
286 if (!(lapic_timer_reliable_states & (1 << (cstate))))
287 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
288
Deepthi Dharware978aa72011-10-28 16:20:09 +0530289 /* Update cpuidle counters */
290 dev->last_residency = (int)usec_delta;
291
292 return index;
Len Brown26717172010-03-08 14:07:30 -0500293}
294
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800295static void __setup_broadcast_timer(void *arg)
296{
297 unsigned long reason = (unsigned long)arg;
298 int cpu = smp_processor_id();
299
300 reason = reason ?
301 CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
302
303 clockevents_notify(reason, &cpu);
304}
305
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200306static int cpu_hotplug_notify(struct notifier_block *n,
307 unsigned long action, void *hcpu)
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800308{
309 int hotcpu = (unsigned long)hcpu;
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200310 struct cpuidle_device *dev;
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800311
312 switch (action & 0xf) {
313 case CPU_ONLINE:
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200314
315 if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
316 smp_call_function_single(hotcpu, __setup_broadcast_timer,
317 (void *)true, 1);
318
319 /*
320 * Some systems can hotplug a cpu at runtime after
321 * the kernel has booted, we have to initialize the
322 * driver in this case
323 */
324 dev = per_cpu_ptr(intel_idle_cpuidle_devices, hotcpu);
325 if (!dev->registered)
326 intel_idle_cpu_init(hotcpu);
327
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800328 break;
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800329 }
330 return NOTIFY_OK;
331}
332
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200333static struct notifier_block cpu_hotplug_notifier = {
334 .notifier_call = cpu_hotplug_notify,
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800335};
336
Len Brown14796fc2011-01-18 20:48:27 -0500337static void auto_demotion_disable(void *dummy)
338{
339 unsigned long long msr_bits;
340
341 rdmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
Andi Kleenb66b8b92012-01-26 00:09:07 +0100342 msr_bits &= ~(icpu->auto_demotion_disable_flags);
Len Brown14796fc2011-01-18 20:48:27 -0500343 wrmsrl(MSR_NHM_SNB_PKG_CST_CFG_CTL, msr_bits);
344}
345
Andi Kleenb66b8b92012-01-26 00:09:07 +0100346static const struct idle_cpu idle_cpu_nehalem = {
347 .state_table = nehalem_cstates,
Andi Kleenb66b8b92012-01-26 00:09:07 +0100348 .auto_demotion_disable_flags = NHM_C1_AUTO_DEMOTE | NHM_C3_AUTO_DEMOTE,
349};
350
351static const struct idle_cpu idle_cpu_atom = {
352 .state_table = atom_cstates,
353};
354
355static const struct idle_cpu idle_cpu_lincroft = {
356 .state_table = atom_cstates,
357 .auto_demotion_disable_flags = ATM_LNC_C6_AUTO_DEMOTE,
358};
359
360static const struct idle_cpu idle_cpu_snb = {
361 .state_table = snb_cstates,
362};
363
364#define ICPU(model, cpu) \
365 { X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
366
367static const struct x86_cpu_id intel_idle_ids[] = {
368 ICPU(0x1a, idle_cpu_nehalem),
369 ICPU(0x1e, idle_cpu_nehalem),
370 ICPU(0x1f, idle_cpu_nehalem),
Ben Hutchings8bf11932012-02-16 04:13:14 +0000371 ICPU(0x25, idle_cpu_nehalem),
372 ICPU(0x2c, idle_cpu_nehalem),
373 ICPU(0x2e, idle_cpu_nehalem),
Andi Kleenb66b8b92012-01-26 00:09:07 +0100374 ICPU(0x1c, idle_cpu_atom),
375 ICPU(0x26, idle_cpu_lincroft),
Ben Hutchings8bf11932012-02-16 04:13:14 +0000376 ICPU(0x2f, idle_cpu_nehalem),
Andi Kleenb66b8b92012-01-26 00:09:07 +0100377 ICPU(0x2a, idle_cpu_snb),
378 ICPU(0x2d, idle_cpu_snb),
379 {}
380};
381MODULE_DEVICE_TABLE(x86cpu, intel_idle_ids);
382
Len Brown26717172010-03-08 14:07:30 -0500383/*
384 * intel_idle_probe()
385 */
386static int intel_idle_probe(void)
387{
Len Brownc4236282010-05-28 02:22:03 -0400388 unsigned int eax, ebx, ecx;
Andi Kleenb66b8b92012-01-26 00:09:07 +0100389 const struct x86_cpu_id *id;
Len Brown26717172010-03-08 14:07:30 -0500390
391 if (max_cstate == 0) {
392 pr_debug(PREFIX "disabled\n");
393 return -EPERM;
394 }
395
Andi Kleenb66b8b92012-01-26 00:09:07 +0100396 id = x86_match_cpu(intel_idle_ids);
397 if (!id) {
398 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
399 boot_cpu_data.x86 == 6)
400 pr_debug(PREFIX "does not run on family %d model %d\n",
401 boot_cpu_data.x86, boot_cpu_data.x86_model);
Len Brown26717172010-03-08 14:07:30 -0500402 return -ENODEV;
Andi Kleenb66b8b92012-01-26 00:09:07 +0100403 }
Len Brown26717172010-03-08 14:07:30 -0500404
405 if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
406 return -ENODEV;
407
Len Brownc4236282010-05-28 02:22:03 -0400408 cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
Len Brown26717172010-03-08 14:07:30 -0500409
410 if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
Thomas Renninger5c2a9f02011-12-04 22:17:29 +0100411 !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
412 !mwait_substates)
Len Brown26717172010-03-08 14:07:30 -0500413 return -ENODEV;
Len Brown26717172010-03-08 14:07:30 -0500414
Len Brownc4236282010-05-28 02:22:03 -0400415 pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates);
Len Brown26717172010-03-08 14:07:30 -0500416
Andi Kleenb66b8b92012-01-26 00:09:07 +0100417 icpu = (const struct idle_cpu *)id->driver_data;
418 cpuidle_state_table = icpu->state_table;
Len Brown26717172010-03-08 14:07:30 -0500419
Len Brown56b9aea2010-12-02 01:19:32 -0500420 if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800421 lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200422 else
Shaohua Li39a74fd2012-01-10 15:48:19 -0800423 on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200424
425 register_cpu_notifier(&cpu_hotplug_notifier);
Len Brown56b9aea2010-12-02 01:19:32 -0500426
Len Brown26717172010-03-08 14:07:30 -0500427 pr_debug(PREFIX "v" INTEL_IDLE_VERSION
428 " model 0x%X\n", boot_cpu_data.x86_model);
429
430 pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n",
431 lapic_timer_reliable_states);
432 return 0;
433}
434
435/*
436 * intel_idle_cpuidle_devices_uninit()
437 * unregister, free cpuidle_devices
438 */
439static void intel_idle_cpuidle_devices_uninit(void)
440{
441 int i;
442 struct cpuidle_device *dev;
443
444 for_each_online_cpu(i) {
445 dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
446 cpuidle_unregister_device(dev);
447 }
448
449 free_percpu(intel_idle_cpuidle_devices);
450 return;
451}
452/*
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530453 * intel_idle_cpuidle_driver_init()
454 * allocate, initialize cpuidle_states
455 */
456static int intel_idle_cpuidle_driver_init(void)
457{
458 int cstate;
459 struct cpuidle_driver *drv = &intel_idle_driver;
460
461 drv->state_count = 1;
462
463 for (cstate = 1; cstate < MWAIT_MAX_NUM_CSTATES; ++cstate) {
464 int num_substates;
465
466 if (cstate > max_cstate) {
467 printk(PREFIX "max_cstate %d reached\n",
468 max_cstate);
469 break;
470 }
471
472 /* does the state exist in CPUID.MWAIT? */
473 num_substates = (mwait_substates >> ((cstate) * 4))
474 & MWAIT_SUBSTATE_MASK;
475 if (num_substates == 0)
476 continue;
477 /* is the state not enabled? */
478 if (cpuidle_state_table[cstate].enter == NULL) {
479 /* does the driver not know about the state? */
480 if (*cpuidle_state_table[cstate].name == '\0')
481 pr_debug(PREFIX "unaware of model 0x%x"
482 " MWAIT %d please"
483 " contact lenb@kernel.org",
484 boot_cpu_data.x86_model, cstate);
485 continue;
486 }
487
488 if ((cstate > 2) &&
489 !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
490 mark_tsc_unstable("TSC halts in idle"
491 " states deeper than C2");
492
493 drv->states[drv->state_count] = /* structure copy */
494 cpuidle_state_table[cstate];
495
496 drv->state_count += 1;
497 }
498
Andi Kleenb66b8b92012-01-26 00:09:07 +0100499 if (icpu->auto_demotion_disable_flags)
Shaohua Li39a74fd2012-01-10 15:48:19 -0800500 on_each_cpu(auto_demotion_disable, NULL, 1);
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530501
502 return 0;
503}
504
505
506/*
Thomas Renninger65b7f832012-01-17 22:40:08 +0100507 * intel_idle_cpu_init()
Len Brown26717172010-03-08 14:07:30 -0500508 * allocate, initialize, register cpuidle_devices
Thomas Renninger65b7f832012-01-17 22:40:08 +0100509 * @cpu: cpu/core to initialize
Len Brown26717172010-03-08 14:07:30 -0500510 */
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200511static int intel_idle_cpu_init(int cpu)
Len Brown26717172010-03-08 14:07:30 -0500512{
Thomas Renninger65b7f832012-01-17 22:40:08 +0100513 int cstate;
Len Brown26717172010-03-08 14:07:30 -0500514 struct cpuidle_device *dev;
515
Thomas Renninger65b7f832012-01-17 22:40:08 +0100516 dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
Len Brown26717172010-03-08 14:07:30 -0500517
Thomas Renninger65b7f832012-01-17 22:40:08 +0100518 dev->state_count = 1;
Len Brown26717172010-03-08 14:07:30 -0500519
Thomas Renninger65b7f832012-01-17 22:40:08 +0100520 for (cstate = 1; cstate < MWAIT_MAX_NUM_CSTATES; ++cstate) {
521 int num_substates;
Len Brown26717172010-03-08 14:07:30 -0500522
Thomas Renninger65b7f832012-01-17 22:40:08 +0100523 if (cstate > max_cstate) {
Marcos Paulo de Souzadc716e92012-03-21 16:33:43 -0700524 printk(PREFIX "max_cstate %d reached\n", max_cstate);
Thomas Renninger65b7f832012-01-17 22:40:08 +0100525 break;
526 }
Len Brown26717172010-03-08 14:07:30 -0500527
Thomas Renninger65b7f832012-01-17 22:40:08 +0100528 /* does the state exist in CPUID.MWAIT? */
529 num_substates = (mwait_substates >> ((cstate) * 4))
530 & MWAIT_SUBSTATE_MASK;
531 if (num_substates == 0)
532 continue;
533 /* is the state not enabled? */
534 if (cpuidle_state_table[cstate].enter == NULL)
535 continue;
Len Brown26717172010-03-08 14:07:30 -0500536
Thomas Renninger65b7f832012-01-17 22:40:08 +0100537 dev->states_usage[dev->state_count].driver_data =
538 (void *)get_driver_data(cstate);
Len Brown26717172010-03-08 14:07:30 -0500539
Marcos Paulo de Souzadc716e92012-03-21 16:33:43 -0700540 dev->state_count += 1;
541 }
542
Thomas Renninger65b7f832012-01-17 22:40:08 +0100543 dev->cpu = cpu;
Len Brown26717172010-03-08 14:07:30 -0500544
Thomas Renninger65b7f832012-01-17 22:40:08 +0100545 if (cpuidle_register_device(dev)) {
546 pr_debug(PREFIX "cpuidle_register_device %d failed!\n", cpu);
547 intel_idle_cpuidle_devices_uninit();
548 return -EIO;
Len Brown26717172010-03-08 14:07:30 -0500549 }
550
Andi Kleenb66b8b92012-01-26 00:09:07 +0100551 if (icpu->auto_demotion_disable_flags)
Thomas Renninger65b7f832012-01-17 22:40:08 +0100552 smp_call_function_single(cpu, auto_demotion_disable, NULL, 1);
553
Len Brown26717172010-03-08 14:07:30 -0500554 return 0;
555}
Len Brown26717172010-03-08 14:07:30 -0500556
557static int __init intel_idle_init(void)
558{
Thomas Renninger65b7f832012-01-17 22:40:08 +0100559 int retval, i;
Len Brown26717172010-03-08 14:07:30 -0500560
Thomas Renningerd1896042010-11-03 17:06:14 +0100561 /* Do not load intel_idle at all for now if idle= is passed */
562 if (boot_option_idle_override != IDLE_NO_OVERRIDE)
563 return -ENODEV;
564
Len Brown26717172010-03-08 14:07:30 -0500565 retval = intel_idle_probe();
566 if (retval)
567 return retval;
568
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530569 intel_idle_cpuidle_driver_init();
Len Brown26717172010-03-08 14:07:30 -0500570 retval = cpuidle_register_driver(&intel_idle_driver);
571 if (retval) {
572 printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
573 cpuidle_get_driver()->name);
574 return retval;
575 }
576
Thomas Renninger65b7f832012-01-17 22:40:08 +0100577 intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
578 if (intel_idle_cpuidle_devices == NULL)
579 return -ENOMEM;
580
581 for_each_online_cpu(i) {
582 retval = intel_idle_cpu_init(i);
583 if (retval) {
584 cpuidle_unregister_driver(&intel_idle_driver);
585 return retval;
586 }
Len Brown26717172010-03-08 14:07:30 -0500587 }
588
589 return 0;
590}
591
592static void __exit intel_idle_exit(void)
593{
594 intel_idle_cpuidle_devices_uninit();
595 cpuidle_unregister_driver(&intel_idle_driver);
596
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200597
598 if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
Shaohua Li39a74fd2012-01-10 15:48:19 -0800599 on_each_cpu(__setup_broadcast_timer, (void *)false, 1);
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200600 unregister_cpu_notifier(&cpu_hotplug_notifier);
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800601
Len Brown26717172010-03-08 14:07:30 -0500602 return;
603}
604
605module_init(intel_idle_init);
606module_exit(intel_idle_exit);
607
Len Brown26717172010-03-08 14:07:30 -0500608module_param(max_cstate, int, 0444);
Len Brown26717172010-03-08 14:07:30 -0500609
610MODULE_AUTHOR("Len Brown <len.brown@intel.com>");
611MODULE_DESCRIPTION("Cpuidle driver for Intel Hardware v" INTEL_IDLE_VERSION);
612MODULE_LICENSE("GPL");