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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>
Len Brown26717172010-03-08 14:07:30 -050059#include <trace/events/power.h>
60#include <linux/sched.h>
Shaohua Li2a2d31c2011-01-10 09:38:12 +080061#include <linux/notifier.h>
62#include <linux/cpu.h>
Paul Gortmaker7c52d552011-05-27 12:33:10 -040063#include <linux/module.h>
Andi Kleenb66b8b92012-01-26 00:09:07 +010064#include <asm/cpu_device_id.h>
H. Peter Anvinbc83ccc2010-09-17 15:36:40 -070065#include <asm/mwait.h>
Len Brown14796fc2011-01-18 20:48:27 -050066#include <asm/msr.h>
Len Brown26717172010-03-08 14:07:30 -050067
68#define INTEL_IDLE_VERSION "0.4"
69#define PREFIX "intel_idle: "
70
Len Brown26717172010-03-08 14:07:30 -050071static struct cpuidle_driver intel_idle_driver = {
72 .name = "intel_idle",
73 .owner = THIS_MODULE,
Julius Wernera474a512012-11-27 14:17:58 +010074 .en_core_tk_irqen = 1,
Len Brown26717172010-03-08 14:07:30 -050075};
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 Brownb1beab42013-01-31 19:55:37 -0500112 * MWAIT takes an 8-bit "hint" in EAX "suggesting"
113 * the C-state (top nibble) and sub-state (bottom nibble)
114 * 0x00 means "MWAIT(C1)", 0x10 means "MWAIT(C2)" etc.
115 *
116 * We store the hint at the top of our "flags" for each state.
117 */
118#define flg2MWAIT(flags) (((flags) >> 24) & 0xFF)
119#define MWAIT2flg(eax) ((eax & 0xFF) << 24)
120
121/*
Len Brown26717172010-03-08 14:07:30 -0500122 * States are indexed by the cstate number,
123 * which is also the index into the MWAIT hint array.
124 * Thus C0 is a dummy.
125 */
126static struct cpuidle_state nehalem_cstates[MWAIT_MAX_NUM_CSTATES] = {
127 { /* MWAIT C0 */ },
128 { /* MWAIT C1 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100129 .name = "C1-NHM",
Len Brown26717172010-03-08 14:07:30 -0500130 .desc = "MWAIT 0x00",
Len Brownb1beab42013-01-31 19:55:37 -0500131 .flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_TIME_VALID,
Len Brown26717172010-03-08 14:07:30 -0500132 .exit_latency = 3,
Len Brown26717172010-03-08 14:07:30 -0500133 .target_residency = 6,
134 .enter = &intel_idle },
135 { /* MWAIT C2 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100136 .name = "C3-NHM",
Len Brown26717172010-03-08 14:07:30 -0500137 .desc = "MWAIT 0x10",
Len Brownb1beab42013-01-31 19:55:37 -0500138 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown26717172010-03-08 14:07:30 -0500139 .exit_latency = 20,
Len Brown26717172010-03-08 14:07:30 -0500140 .target_residency = 80,
141 .enter = &intel_idle },
142 { /* MWAIT C3 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100143 .name = "C6-NHM",
Len Brown26717172010-03-08 14:07:30 -0500144 .desc = "MWAIT 0x20",
Len Brownb1beab42013-01-31 19:55:37 -0500145 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown26717172010-03-08 14:07:30 -0500146 .exit_latency = 200,
Len Brown26717172010-03-08 14:07:30 -0500147 .target_residency = 800,
148 .enter = &intel_idle },
149};
150
Len Brownd13780d2010-07-07 00:12:03 -0400151static struct cpuidle_state snb_cstates[MWAIT_MAX_NUM_CSTATES] = {
152 { /* MWAIT C0 */ },
153 { /* MWAIT C1 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100154 .name = "C1-SNB",
Len Brownd13780d2010-07-07 00:12:03 -0400155 .desc = "MWAIT 0x00",
Len Brownb1beab42013-01-31 19:55:37 -0500156 .flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_TIME_VALID,
Len Brownd13780d2010-07-07 00:12:03 -0400157 .exit_latency = 1,
Len Brownddbd5502010-12-13 18:28:22 -0500158 .target_residency = 1,
Len Brownd13780d2010-07-07 00:12:03 -0400159 .enter = &intel_idle },
160 { /* MWAIT C2 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100161 .name = "C3-SNB",
Len Brownd13780d2010-07-07 00:12:03 -0400162 .desc = "MWAIT 0x10",
Len Brownb1beab42013-01-31 19:55:37 -0500163 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brownd13780d2010-07-07 00:12:03 -0400164 .exit_latency = 80,
Len Brownddbd5502010-12-13 18:28:22 -0500165 .target_residency = 211,
Len Brownd13780d2010-07-07 00:12:03 -0400166 .enter = &intel_idle },
167 { /* MWAIT C3 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100168 .name = "C6-SNB",
Len Brownd13780d2010-07-07 00:12:03 -0400169 .desc = "MWAIT 0x20",
Len Brownb1beab42013-01-31 19:55:37 -0500170 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brownd13780d2010-07-07 00:12:03 -0400171 .exit_latency = 104,
Len Brownddbd5502010-12-13 18:28:22 -0500172 .target_residency = 345,
Len Brownd13780d2010-07-07 00:12:03 -0400173 .enter = &intel_idle },
174 { /* MWAIT C4 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100175 .name = "C7-SNB",
Len Brownd13780d2010-07-07 00:12:03 -0400176 .desc = "MWAIT 0x30",
Len Brownb1beab42013-01-31 19:55:37 -0500177 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brownd13780d2010-07-07 00:12:03 -0400178 .exit_latency = 109,
Len Brownddbd5502010-12-13 18:28:22 -0500179 .target_residency = 345,
Len Brownd13780d2010-07-07 00:12:03 -0400180 .enter = &intel_idle },
181};
182
Len Brown6edab082012-06-01 19:45:32 -0400183static struct cpuidle_state ivb_cstates[MWAIT_MAX_NUM_CSTATES] = {
184 { /* MWAIT C0 */ },
185 { /* MWAIT C1 */
186 .name = "C1-IVB",
187 .desc = "MWAIT 0x00",
Len Brownb1beab42013-01-31 19:55:37 -0500188 .flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_TIME_VALID,
Len Brown6edab082012-06-01 19:45:32 -0400189 .exit_latency = 1,
190 .target_residency = 1,
191 .enter = &intel_idle },
192 { /* MWAIT C2 */
193 .name = "C3-IVB",
194 .desc = "MWAIT 0x10",
Len Brownb1beab42013-01-31 19:55:37 -0500195 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown6edab082012-06-01 19:45:32 -0400196 .exit_latency = 59,
197 .target_residency = 156,
198 .enter = &intel_idle },
199 { /* MWAIT C3 */
200 .name = "C6-IVB",
201 .desc = "MWAIT 0x20",
Len Brownb1beab42013-01-31 19:55:37 -0500202 .flags = MWAIT2flg(0x20) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown6edab082012-06-01 19:45:32 -0400203 .exit_latency = 80,
204 .target_residency = 300,
205 .enter = &intel_idle },
206 { /* MWAIT C4 */
207 .name = "C7-IVB",
208 .desc = "MWAIT 0x30",
Len Brownb1beab42013-01-31 19:55:37 -0500209 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown6edab082012-06-01 19:45:32 -0400210 .exit_latency = 87,
211 .target_residency = 300,
212 .enter = &intel_idle },
213};
214
Len Brown26717172010-03-08 14:07:30 -0500215static struct cpuidle_state atom_cstates[MWAIT_MAX_NUM_CSTATES] = {
216 { /* MWAIT C0 */ },
217 { /* MWAIT C1 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100218 .name = "C1-ATM",
Len Brown26717172010-03-08 14:07:30 -0500219 .desc = "MWAIT 0x00",
Len Brownb1beab42013-01-31 19:55:37 -0500220 .flags = MWAIT2flg(0x00) | CPUIDLE_FLAG_TIME_VALID,
Len Brown26717172010-03-08 14:07:30 -0500221 .exit_latency = 1,
Len Brown26717172010-03-08 14:07:30 -0500222 .target_residency = 4,
223 .enter = &intel_idle },
224 { /* MWAIT C2 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100225 .name = "C2-ATM",
Len Brown26717172010-03-08 14:07:30 -0500226 .desc = "MWAIT 0x10",
Len Brownb1beab42013-01-31 19:55:37 -0500227 .flags = MWAIT2flg(0x10) | CPUIDLE_FLAG_TIME_VALID,
Len Brown26717172010-03-08 14:07:30 -0500228 .exit_latency = 20,
Len Brown26717172010-03-08 14:07:30 -0500229 .target_residency = 80,
230 .enter = &intel_idle },
231 { /* MWAIT C3 */ },
232 { /* MWAIT C4 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100233 .name = "C4-ATM",
Len Brown26717172010-03-08 14:07:30 -0500234 .desc = "MWAIT 0x30",
Len Brownb1beab42013-01-31 19:55:37 -0500235 .flags = MWAIT2flg(0x30) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown26717172010-03-08 14:07:30 -0500236 .exit_latency = 100,
Len Brown26717172010-03-08 14:07:30 -0500237 .target_residency = 400,
238 .enter = &intel_idle },
239 { /* MWAIT C5 */ },
240 { /* MWAIT C6 */
Thomas Renninger15e123e2011-02-27 22:36:43 +0100241 .name = "C6-ATM",
Len Brown7fcca7d2010-10-05 13:43:14 -0400242 .desc = "MWAIT 0x52",
Len Brownb1beab42013-01-31 19:55:37 -0500243 .flags = MWAIT2flg(0x52) | CPUIDLE_FLAG_TIME_VALID | CPUIDLE_FLAG_TLB_FLUSHED,
Len Brown7fcca7d2010-10-05 13:43:14 -0400244 .exit_latency = 140,
Len Brown7fcca7d2010-10-05 13:43:14 -0400245 .target_residency = 560,
246 .enter = &intel_idle },
Len Brown26717172010-03-08 14:07:30 -0500247};
248
Len Brown26717172010-03-08 14:07:30 -0500249/**
250 * intel_idle
251 * @dev: cpuidle_device
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530252 * @drv: cpuidle driver
Deepthi Dharware978aa72011-10-28 16:20:09 +0530253 * @index: index of cpuidle state
Len Brown26717172010-03-08 14:07:30 -0500254 *
Yanmin Zhang63ff07b2012-01-10 15:48:21 -0800255 * Must be called under local_irq_disable().
Len Brown26717172010-03-08 14:07:30 -0500256 */
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530257static int intel_idle(struct cpuidle_device *dev,
258 struct cpuidle_driver *drv, int index)
Len Brown26717172010-03-08 14:07:30 -0500259{
260 unsigned long ecx = 1; /* break on interrupt flag */
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530261 struct cpuidle_state *state = &drv->states[index];
Len Brownb1beab42013-01-31 19:55:37 -0500262 unsigned long eax = flg2MWAIT(state->flags);
Len Brown26717172010-03-08 14:07:30 -0500263 unsigned int cstate;
Len Brown26717172010-03-08 14:07:30 -0500264 int cpu = smp_processor_id();
265
266 cstate = (((eax) >> MWAIT_SUBSTATE_SIZE) & MWAIT_CSTATE_MASK) + 1;
267
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400268 /*
Len Brownc8381cc2010-10-15 20:43:06 -0400269 * leave_mm() to avoid costly and often unnecessary wakeups
270 * for flushing the user TLB's associated with the active mm.
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400271 */
Len Brownc8381cc2010-10-15 20:43:06 -0400272 if (state->flags & CPUIDLE_FLAG_TLB_FLUSHED)
Suresh Siddha6110a1f2010-09-30 21:19:07 -0400273 leave_mm(cpu);
274
Len Brown26717172010-03-08 14:07:30 -0500275 if (!(lapic_timer_reliable_states & (1 << (cstate))))
276 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
277
Len Brown26717172010-03-08 14:07:30 -0500278 stop_critical_timings();
Len Brown26717172010-03-08 14:07:30 -0500279 if (!need_resched()) {
280
281 __monitor((void *)&current_thread_info()->flags, 0, 0);
282 smp_mb();
283 if (!need_resched())
284 __mwait(eax, ecx);
285 }
286
287 start_critical_timings();
288
Len Brown26717172010-03-08 14:07:30 -0500289 if (!(lapic_timer_reliable_states & (1 << (cstate))))
290 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
291
Deepthi Dharware978aa72011-10-28 16:20:09 +0530292 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
Len Brown6edab082012-06-01 19:45:32 -0400364static const struct idle_cpu idle_cpu_ivb = {
365 .state_table = ivb_cstates,
366};
367
Andi Kleenb66b8b92012-01-26 00:09:07 +0100368#define ICPU(model, cpu) \
369 { X86_VENDOR_INTEL, 6, model, X86_FEATURE_MWAIT, (unsigned long)&cpu }
370
371static const struct x86_cpu_id intel_idle_ids[] = {
372 ICPU(0x1a, idle_cpu_nehalem),
373 ICPU(0x1e, idle_cpu_nehalem),
374 ICPU(0x1f, idle_cpu_nehalem),
Ben Hutchings8bf11932012-02-16 04:13:14 +0000375 ICPU(0x25, idle_cpu_nehalem),
376 ICPU(0x2c, idle_cpu_nehalem),
377 ICPU(0x2e, idle_cpu_nehalem),
Andi Kleenb66b8b92012-01-26 00:09:07 +0100378 ICPU(0x1c, idle_cpu_atom),
379 ICPU(0x26, idle_cpu_lincroft),
Ben Hutchings8bf11932012-02-16 04:13:14 +0000380 ICPU(0x2f, idle_cpu_nehalem),
Andi Kleenb66b8b92012-01-26 00:09:07 +0100381 ICPU(0x2a, idle_cpu_snb),
382 ICPU(0x2d, idle_cpu_snb),
Len Brown6edab082012-06-01 19:45:32 -0400383 ICPU(0x3a, idle_cpu_ivb),
Len Brown23795e52012-09-26 22:28:21 -0400384 ICPU(0x3e, idle_cpu_ivb),
Andi Kleenb66b8b92012-01-26 00:09:07 +0100385 {}
386};
387MODULE_DEVICE_TABLE(x86cpu, intel_idle_ids);
388
Len Brown26717172010-03-08 14:07:30 -0500389/*
390 * intel_idle_probe()
391 */
392static int intel_idle_probe(void)
393{
Len Brownc4236282010-05-28 02:22:03 -0400394 unsigned int eax, ebx, ecx;
Andi Kleenb66b8b92012-01-26 00:09:07 +0100395 const struct x86_cpu_id *id;
Len Brown26717172010-03-08 14:07:30 -0500396
397 if (max_cstate == 0) {
398 pr_debug(PREFIX "disabled\n");
399 return -EPERM;
400 }
401
Andi Kleenb66b8b92012-01-26 00:09:07 +0100402 id = x86_match_cpu(intel_idle_ids);
403 if (!id) {
404 if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL &&
405 boot_cpu_data.x86 == 6)
406 pr_debug(PREFIX "does not run on family %d model %d\n",
407 boot_cpu_data.x86, boot_cpu_data.x86_model);
Len Brown26717172010-03-08 14:07:30 -0500408 return -ENODEV;
Andi Kleenb66b8b92012-01-26 00:09:07 +0100409 }
Len Brown26717172010-03-08 14:07:30 -0500410
411 if (boot_cpu_data.cpuid_level < CPUID_MWAIT_LEAF)
412 return -ENODEV;
413
Len Brownc4236282010-05-28 02:22:03 -0400414 cpuid(CPUID_MWAIT_LEAF, &eax, &ebx, &ecx, &mwait_substates);
Len Brown26717172010-03-08 14:07:30 -0500415
416 if (!(ecx & CPUID5_ECX_EXTENSIONS_SUPPORTED) ||
Thomas Renninger5c2a9f02011-12-04 22:17:29 +0100417 !(ecx & CPUID5_ECX_INTERRUPT_BREAK) ||
418 !mwait_substates)
Len Brown26717172010-03-08 14:07:30 -0500419 return -ENODEV;
Len Brown26717172010-03-08 14:07:30 -0500420
Len Brownc4236282010-05-28 02:22:03 -0400421 pr_debug(PREFIX "MWAIT substates: 0x%x\n", mwait_substates);
Len Brown26717172010-03-08 14:07:30 -0500422
Andi Kleenb66b8b92012-01-26 00:09:07 +0100423 icpu = (const struct idle_cpu *)id->driver_data;
424 cpuidle_state_table = icpu->state_table;
Len Brown26717172010-03-08 14:07:30 -0500425
Len Brown56b9aea2010-12-02 01:19:32 -0500426 if (boot_cpu_has(X86_FEATURE_ARAT)) /* Always Reliable APIC Timer */
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800427 lapic_timer_reliable_states = LAPIC_TIMER_ALWAYS_RELIABLE;
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200428 else
Shaohua Li39a74fd2012-01-10 15:48:19 -0800429 on_each_cpu(__setup_broadcast_timer, (void *)true, 1);
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200430
Len Brown26717172010-03-08 14:07:30 -0500431 pr_debug(PREFIX "v" INTEL_IDLE_VERSION
432 " model 0x%X\n", boot_cpu_data.x86_model);
433
434 pr_debug(PREFIX "lapic_timer_reliable_states 0x%x\n",
435 lapic_timer_reliable_states);
436 return 0;
437}
438
439/*
440 * intel_idle_cpuidle_devices_uninit()
441 * unregister, free cpuidle_devices
442 */
443static void intel_idle_cpuidle_devices_uninit(void)
444{
445 int i;
446 struct cpuidle_device *dev;
447
448 for_each_online_cpu(i) {
449 dev = per_cpu_ptr(intel_idle_cpuidle_devices, i);
450 cpuidle_unregister_device(dev);
451 }
452
453 free_percpu(intel_idle_cpuidle_devices);
454 return;
455}
456/*
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530457 * intel_idle_cpuidle_driver_init()
458 * allocate, initialize cpuidle_states
459 */
460static int intel_idle_cpuidle_driver_init(void)
461{
462 int cstate;
463 struct cpuidle_driver *drv = &intel_idle_driver;
464
465 drv->state_count = 1;
466
467 for (cstate = 1; cstate < MWAIT_MAX_NUM_CSTATES; ++cstate) {
468 int num_substates;
469
470 if (cstate > max_cstate) {
471 printk(PREFIX "max_cstate %d reached\n",
472 max_cstate);
473 break;
474 }
475
476 /* does the state exist in CPUID.MWAIT? */
477 num_substates = (mwait_substates >> ((cstate) * 4))
478 & MWAIT_SUBSTATE_MASK;
479 if (num_substates == 0)
480 continue;
481 /* is the state not enabled? */
482 if (cpuidle_state_table[cstate].enter == NULL) {
483 /* does the driver not know about the state? */
484 if (*cpuidle_state_table[cstate].name == '\0')
485 pr_debug(PREFIX "unaware of model 0x%x"
486 " MWAIT %d please"
Youquan Song17915d52012-12-18 13:54:22 +0100487 " contact lenb@kernel.org\n",
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530488 boot_cpu_data.x86_model, cstate);
489 continue;
490 }
491
492 if ((cstate > 2) &&
493 !boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
494 mark_tsc_unstable("TSC halts in idle"
495 " states deeper than C2");
496
497 drv->states[drv->state_count] = /* structure copy */
498 cpuidle_state_table[cstate];
499
500 drv->state_count += 1;
501 }
502
Andi Kleenb66b8b92012-01-26 00:09:07 +0100503 if (icpu->auto_demotion_disable_flags)
Shaohua Li39a74fd2012-01-10 15:48:19 -0800504 on_each_cpu(auto_demotion_disable, NULL, 1);
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530505
506 return 0;
507}
508
509
510/*
Thomas Renninger65b7f832012-01-17 22:40:08 +0100511 * intel_idle_cpu_init()
Len Brown26717172010-03-08 14:07:30 -0500512 * allocate, initialize, register cpuidle_devices
Thomas Renninger65b7f832012-01-17 22:40:08 +0100513 * @cpu: cpu/core to initialize
Len Brown26717172010-03-08 14:07:30 -0500514 */
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200515static int intel_idle_cpu_init(int cpu)
Len Brown26717172010-03-08 14:07:30 -0500516{
Thomas Renninger65b7f832012-01-17 22:40:08 +0100517 int cstate;
Len Brown26717172010-03-08 14:07:30 -0500518 struct cpuidle_device *dev;
519
Thomas Renninger65b7f832012-01-17 22:40:08 +0100520 dev = per_cpu_ptr(intel_idle_cpuidle_devices, cpu);
Len Brown26717172010-03-08 14:07:30 -0500521
Thomas Renninger65b7f832012-01-17 22:40:08 +0100522 dev->state_count = 1;
Len Brown26717172010-03-08 14:07:30 -0500523
Thomas Renninger65b7f832012-01-17 22:40:08 +0100524 for (cstate = 1; cstate < MWAIT_MAX_NUM_CSTATES; ++cstate) {
525 int num_substates;
Len Brown26717172010-03-08 14:07:30 -0500526
Thomas Renninger65b7f832012-01-17 22:40:08 +0100527 if (cstate > max_cstate) {
Marcos Paulo de Souzadc716e92012-03-21 16:33:43 -0700528 printk(PREFIX "max_cstate %d reached\n", max_cstate);
Thomas Renninger65b7f832012-01-17 22:40:08 +0100529 break;
530 }
Len Brown26717172010-03-08 14:07:30 -0500531
Thomas Renninger65b7f832012-01-17 22:40:08 +0100532 /* does the state exist in CPUID.MWAIT? */
533 num_substates = (mwait_substates >> ((cstate) * 4))
534 & MWAIT_SUBSTATE_MASK;
535 if (num_substates == 0)
536 continue;
537 /* is the state not enabled? */
538 if (cpuidle_state_table[cstate].enter == NULL)
539 continue;
Len Brown26717172010-03-08 14:07:30 -0500540
Marcos Paulo de Souzadc716e92012-03-21 16:33:43 -0700541 dev->state_count += 1;
542 }
543
Thomas Renninger65b7f832012-01-17 22:40:08 +0100544 dev->cpu = cpu;
Len Brown26717172010-03-08 14:07:30 -0500545
Thomas Renninger65b7f832012-01-17 22:40:08 +0100546 if (cpuidle_register_device(dev)) {
547 pr_debug(PREFIX "cpuidle_register_device %d failed!\n", cpu);
548 intel_idle_cpuidle_devices_uninit();
549 return -EIO;
Len Brown26717172010-03-08 14:07:30 -0500550 }
551
Andi Kleenb66b8b92012-01-26 00:09:07 +0100552 if (icpu->auto_demotion_disable_flags)
Thomas Renninger65b7f832012-01-17 22:40:08 +0100553 smp_call_function_single(cpu, auto_demotion_disable, NULL, 1);
554
Len Brown26717172010-03-08 14:07:30 -0500555 return 0;
556}
Len Brown26717172010-03-08 14:07:30 -0500557
558static int __init intel_idle_init(void)
559{
Thomas Renninger65b7f832012-01-17 22:40:08 +0100560 int retval, i;
Len Brown26717172010-03-08 14:07:30 -0500561
Thomas Renningerd1896042010-11-03 17:06:14 +0100562 /* Do not load intel_idle at all for now if idle= is passed */
563 if (boot_option_idle_override != IDLE_NO_OVERRIDE)
564 return -ENODEV;
565
Len Brown26717172010-03-08 14:07:30 -0500566 retval = intel_idle_probe();
567 if (retval)
568 return retval;
569
Deepthi Dharwar46bcfad2011-10-28 16:20:42 +0530570 intel_idle_cpuidle_driver_init();
Len Brown26717172010-03-08 14:07:30 -0500571 retval = cpuidle_register_driver(&intel_idle_driver);
572 if (retval) {
Konrad Rzeszutek Wilk3735d522012-08-16 22:06:55 +0200573 struct cpuidle_driver *drv = cpuidle_get_driver();
Len Brown26717172010-03-08 14:07:30 -0500574 printk(KERN_DEBUG PREFIX "intel_idle yielding to %s",
Konrad Rzeszutek Wilk3735d522012-08-16 22:06:55 +0200575 drv ? drv->name : "none");
Len Brown26717172010-03-08 14:07:30 -0500576 return retval;
577 }
578
Thomas Renninger65b7f832012-01-17 22:40:08 +0100579 intel_idle_cpuidle_devices = alloc_percpu(struct cpuidle_device);
580 if (intel_idle_cpuidle_devices == NULL)
581 return -ENOMEM;
582
583 for_each_online_cpu(i) {
584 retval = intel_idle_cpu_init(i);
585 if (retval) {
586 cpuidle_unregister_driver(&intel_idle_driver);
587 return retval;
588 }
Len Brown26717172010-03-08 14:07:30 -0500589 }
Konrad Rzeszutek Wilk6f8c2e72013-01-16 23:40:01 +0100590 register_cpu_notifier(&cpu_hotplug_notifier);
Len Brown26717172010-03-08 14:07:30 -0500591
592 return 0;
593}
594
595static void __exit intel_idle_exit(void)
596{
597 intel_idle_cpuidle_devices_uninit();
598 cpuidle_unregister_driver(&intel_idle_driver);
599
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200600
601 if (lapic_timer_reliable_states != LAPIC_TIMER_ALWAYS_RELIABLE)
Shaohua Li39a74fd2012-01-10 15:48:19 -0800602 on_each_cpu(__setup_broadcast_timer, (void *)false, 1);
Daniel Lezcano25ac7762012-07-05 15:23:25 +0200603 unregister_cpu_notifier(&cpu_hotplug_notifier);
Shaohua Li2a2d31c2011-01-10 09:38:12 +0800604
Len Brown26717172010-03-08 14:07:30 -0500605 return;
606}
607
608module_init(intel_idle_init);
609module_exit(intel_idle_exit);
610
Len Brown26717172010-03-08 14:07:30 -0500611module_param(max_cstate, int, 0444);
Len Brown26717172010-03-08 14:07:30 -0500612
613MODULE_AUTHOR("Len Brown <len.brown@intel.com>");
614MODULE_DESCRIPTION("Cpuidle driver for Intel Hardware v" INTEL_IDLE_VERSION);
615MODULE_LICENSE("GPL");