blob: 4e1daca5ce3b900c21955dda15b62c11415f6bee [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * cpufreq driver for Enhanced SpeedStep, as found in Intel's Pentium
3 * M (part of the Centrino chipset).
4 *
Jeremy Fitzhardinge491b07c2006-06-21 13:15:48 -07005 * Since the original Pentium M, most new Intel CPUs support Enhanced
6 * SpeedStep.
7 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07008 * Despite the "SpeedStep" in the name, this is almost entirely unlike
9 * traditional SpeedStep.
10 *
11 * Modelled on speedstep.c
12 *
13 * Copyright (C) 2003 Jeremy Fitzhardinge <jeremy@goop.org>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014 */
15
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/init.h>
19#include <linux/cpufreq.h>
Tim Schmielau4e57b682005-10-30 15:03:48 -080020#include <linux/sched.h> /* current */
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/delay.h>
22#include <linux/compiler.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090023#include <linux/gfp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <asm/msr.h>
26#include <asm/processor.h>
27#include <asm/cpufeature.h>
Andi Kleenfa8031a2012-01-26 00:09:12 +010028#include <asm/cpu_device_id.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#define PFX "speedstep-centrino: "
Németh Márton8d592252008-10-09 14:59:17 +020031#define MAINTAINER "cpufreq@vger.kernel.org"
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
Gary Hade8b9c6672006-11-10 11:20:47 -080033#define INTEL_MSR_RANGE (0xffff)
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35struct cpu_id
36{
37 __u8 x86; /* CPU family */
38 __u8 x86_model; /* model */
39 __u8 x86_mask; /* stepping */
40};
41
42enum {
43 CPU_BANIAS,
44 CPU_DOTHAN_A1,
45 CPU_DOTHAN_A2,
46 CPU_DOTHAN_B0,
Dave Jones82828642005-05-31 19:03:43 -070047 CPU_MP4HT_D0,
48 CPU_MP4HT_E0,
Linus Torvalds1da177e2005-04-16 15:20:36 -070049};
50
51static const struct cpu_id cpu_ids[] = {
52 [CPU_BANIAS] = { 6, 9, 5 },
53 [CPU_DOTHAN_A1] = { 6, 13, 1 },
54 [CPU_DOTHAN_A2] = { 6, 13, 2 },
55 [CPU_DOTHAN_B0] = { 6, 13, 6 },
Dave Jones82828642005-05-31 19:03:43 -070056 [CPU_MP4HT_D0] = {15, 3, 4 },
57 [CPU_MP4HT_E0] = {15, 4, 1 },
Linus Torvalds1da177e2005-04-16 15:20:36 -070058};
Tobias Klauser38e548e2005-11-07 00:58:31 -080059#define N_IDS ARRAY_SIZE(cpu_ids)
Linus Torvalds1da177e2005-04-16 15:20:36 -070060
61struct cpu_model
62{
63 const struct cpu_id *cpu_id;
64 const char *model_name;
65 unsigned max_freq; /* max clock in kHz */
66
67 struct cpufreq_frequency_table *op_points; /* clock/voltage pairs */
68};
Mike Travisc4762ab2008-07-18 18:11:34 -070069static int centrino_verify_cpu_id(const struct cpuinfo_x86 *c,
70 const struct cpu_id *x);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071
72/* Operating points for current CPU */
Mike Travisc4762ab2008-07-18 18:11:34 -070073static DEFINE_PER_CPU(struct cpu_model *, centrino_model);
74static DEFINE_PER_CPU(const struct cpu_id *, centrino_cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76static struct cpufreq_driver centrino_driver;
77
78#ifdef CONFIG_X86_SPEEDSTEP_CENTRINO_TABLE
79
80/* Computes the correct form for IA32_PERF_CTL MSR for a particular
81 frequency/voltage operating point; frequency in MHz, volts in mV.
Viresh Kumar50701582013-03-30 16:25:15 +053082 This is stored as "driver_data" in the structure. */
Linus Torvalds1da177e2005-04-16 15:20:36 -070083#define OP(mhz, mv) \
84 { \
85 .frequency = (mhz) * 1000, \
Viresh Kumar50701582013-03-30 16:25:15 +053086 .driver_data = (((mhz)/100) << 8) | ((mv - 700) / 16) \
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 }
88
89/*
90 * These voltage tables were derived from the Intel Pentium M
91 * datasheet, document 25261202.pdf, Table 5. I have verified they
92 * are consistent with my IBM ThinkPad X31, which has a 1.3GHz Pentium
93 * M.
94 */
95
96/* Ultra Low Voltage Intel Pentium M processor 900MHz (Banias) */
97static struct cpufreq_frequency_table banias_900[] =
98{
99 OP(600, 844),
100 OP(800, 988),
101 OP(900, 1004),
102 { .frequency = CPUFREQ_TABLE_END }
103};
104
105/* Ultra Low Voltage Intel Pentium M processor 1000MHz (Banias) */
106static struct cpufreq_frequency_table banias_1000[] =
107{
108 OP(600, 844),
109 OP(800, 972),
110 OP(900, 988),
111 OP(1000, 1004),
112 { .frequency = CPUFREQ_TABLE_END }
113};
114
115/* Low Voltage Intel Pentium M processor 1.10GHz (Banias) */
116static struct cpufreq_frequency_table banias_1100[] =
117{
118 OP( 600, 956),
119 OP( 800, 1020),
120 OP( 900, 1100),
121 OP(1000, 1164),
122 OP(1100, 1180),
123 { .frequency = CPUFREQ_TABLE_END }
124};
125
126
127/* Low Voltage Intel Pentium M processor 1.20GHz (Banias) */
128static struct cpufreq_frequency_table banias_1200[] =
129{
130 OP( 600, 956),
131 OP( 800, 1004),
132 OP( 900, 1020),
133 OP(1000, 1100),
134 OP(1100, 1164),
135 OP(1200, 1180),
136 { .frequency = CPUFREQ_TABLE_END }
137};
138
139/* Intel Pentium M processor 1.30GHz (Banias) */
140static struct cpufreq_frequency_table banias_1300[] =
141{
142 OP( 600, 956),
143 OP( 800, 1260),
144 OP(1000, 1292),
145 OP(1200, 1356),
146 OP(1300, 1388),
147 { .frequency = CPUFREQ_TABLE_END }
148};
149
150/* Intel Pentium M processor 1.40GHz (Banias) */
151static struct cpufreq_frequency_table banias_1400[] =
152{
153 OP( 600, 956),
154 OP( 800, 1180),
155 OP(1000, 1308),
156 OP(1200, 1436),
157 OP(1400, 1484),
158 { .frequency = CPUFREQ_TABLE_END }
159};
160
161/* Intel Pentium M processor 1.50GHz (Banias) */
162static struct cpufreq_frequency_table banias_1500[] =
163{
164 OP( 600, 956),
165 OP( 800, 1116),
166 OP(1000, 1228),
167 OP(1200, 1356),
168 OP(1400, 1452),
169 OP(1500, 1484),
170 { .frequency = CPUFREQ_TABLE_END }
171};
172
173/* Intel Pentium M processor 1.60GHz (Banias) */
174static struct cpufreq_frequency_table banias_1600[] =
175{
176 OP( 600, 956),
177 OP( 800, 1036),
178 OP(1000, 1164),
179 OP(1200, 1276),
180 OP(1400, 1420),
181 OP(1600, 1484),
182 { .frequency = CPUFREQ_TABLE_END }
183};
184
185/* Intel Pentium M processor 1.70GHz (Banias) */
186static struct cpufreq_frequency_table banias_1700[] =
187{
188 OP( 600, 956),
189 OP( 800, 1004),
190 OP(1000, 1116),
191 OP(1200, 1228),
192 OP(1400, 1308),
193 OP(1700, 1484),
194 { .frequency = CPUFREQ_TABLE_END }
195};
196#undef OP
197
198#define _BANIAS(cpuid, max, name) \
199{ .cpu_id = cpuid, \
200 .model_name = "Intel(R) Pentium(R) M processor " name "MHz", \
201 .max_freq = (max)*1000, \
202 .op_points = banias_##max, \
203}
204#define BANIAS(max) _BANIAS(&cpu_ids[CPU_BANIAS], max, #max)
205
206/* CPU models, their operating frequency range, and freq/voltage
207 operating points */
208static struct cpu_model models[] =
209{
210 _BANIAS(&cpu_ids[CPU_BANIAS], 900, " 900"),
211 BANIAS(1000),
212 BANIAS(1100),
213 BANIAS(1200),
214 BANIAS(1300),
215 BANIAS(1400),
216 BANIAS(1500),
217 BANIAS(1600),
218 BANIAS(1700),
219
220 /* NULL model_name is a wildcard */
221 { &cpu_ids[CPU_DOTHAN_A1], NULL, 0, NULL },
222 { &cpu_ids[CPU_DOTHAN_A2], NULL, 0, NULL },
223 { &cpu_ids[CPU_DOTHAN_B0], NULL, 0, NULL },
Dave Jones82828642005-05-31 19:03:43 -0700224 { &cpu_ids[CPU_MP4HT_D0], NULL, 0, NULL },
225 { &cpu_ids[CPU_MP4HT_E0], NULL, 0, NULL },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226
227 { NULL, }
228};
229#undef _BANIAS
230#undef BANIAS
231
232static int centrino_cpu_init_table(struct cpufreq_policy *policy)
233{
Mike Travis92cb7612007-10-19 20:35:04 +0200234 struct cpuinfo_x86 *cpu = &cpu_data(policy->cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700235 struct cpu_model *model;
236
237 for(model = models; model->cpu_id != NULL; model++)
238 if (centrino_verify_cpu_id(cpu, model->cpu_id) &&
239 (model->model_name == NULL ||
240 strcmp(cpu->x86_model_id, model->model_name) == 0))
241 break;
242
243 if (model->cpu_id == NULL) {
244 /* No match at all */
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200245 pr_debug("no support for CPU model \"%s\": "
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246 "send /proc/cpuinfo to " MAINTAINER "\n",
247 cpu->x86_model_id);
248 return -ENOENT;
249 }
250
251 if (model->op_points == NULL) {
252 /* Matched a non-match */
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200253 pr_debug("no table support for CPU model \"%s\"\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 cpu->x86_model_id);
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200255 pr_debug("try using the acpi-cpufreq driver\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 return -ENOENT;
257 }
258
Mike Travisc4762ab2008-07-18 18:11:34 -0700259 per_cpu(centrino_model, policy->cpu) = model;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200261 pr_debug("found \"%s\": max frequency: %dkHz\n",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700262 model->model_name, model->max_freq);
263
264 return 0;
265}
266
267#else
Mike Travisc4762ab2008-07-18 18:11:34 -0700268static inline int centrino_cpu_init_table(struct cpufreq_policy *policy)
269{
270 return -ENODEV;
271}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700272#endif /* CONFIG_X86_SPEEDSTEP_CENTRINO_TABLE */
273
Mike Travisc4762ab2008-07-18 18:11:34 -0700274static int centrino_verify_cpu_id(const struct cpuinfo_x86 *c,
275 const struct cpu_id *x)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276{
277 if ((c->x86 == x->x86) &&
278 (c->x86_model == x->x86_model) &&
279 (c->x86_mask == x->x86_mask))
280 return 1;
281 return 0;
282}
283
284/* To be called only after centrino_model is initialized */
285static unsigned extract_clock(unsigned msr, unsigned int cpu, int failsafe)
286{
287 int i;
288
289 /*
290 * Extract clock in kHz from PERF_CTL value
291 * for centrino, as some DSDTs are buggy.
292 * Ideally, this can be done using the acpi_data structure.
293 */
Mike Travisc4762ab2008-07-18 18:11:34 -0700294 if ((per_cpu(centrino_cpu, cpu) == &cpu_ids[CPU_BANIAS]) ||
295 (per_cpu(centrino_cpu, cpu) == &cpu_ids[CPU_DOTHAN_A1]) ||
296 (per_cpu(centrino_cpu, cpu) == &cpu_ids[CPU_DOTHAN_B0])) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700297 msr = (msr >> 8) & 0xff;
298 return msr * 100000;
299 }
300
Mike Travisc4762ab2008-07-18 18:11:34 -0700301 if ((!per_cpu(centrino_model, cpu)) ||
302 (!per_cpu(centrino_model, cpu)->op_points))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 return 0;
304
305 msr &= 0xffff;
Mike Travisc4762ab2008-07-18 18:11:34 -0700306 for (i = 0;
307 per_cpu(centrino_model, cpu)->op_points[i].frequency
308 != CPUFREQ_TABLE_END;
309 i++) {
Viresh Kumar50701582013-03-30 16:25:15 +0530310 if (msr == per_cpu(centrino_model, cpu)->op_points[i].driver_data)
Mike Travisc4762ab2008-07-18 18:11:34 -0700311 return per_cpu(centrino_model, cpu)->
312 op_points[i].frequency;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 }
314 if (failsafe)
Mike Travisc4762ab2008-07-18 18:11:34 -0700315 return per_cpu(centrino_model, cpu)->op_points[i-1].frequency;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 else
317 return 0;
318}
319
320/* Return the current CPU frequency in kHz */
321static unsigned int get_cur_freq(unsigned int cpu)
322{
323 unsigned l, h;
324 unsigned clock_freq;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700325
Rusty Russelle3f996c2009-06-11 22:59:58 +0930326 rdmsr_on_cpu(cpu, MSR_IA32_PERF_STATUS, &l, &h);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700327 clock_freq = extract_clock(l, cpu, 0);
328
329 if (unlikely(clock_freq == 0)) {
330 /*
331 * On some CPUs, we can see transient MSR values (which are
332 * not present in _PSS), while CPU is doing some automatic
333 * P-state transition (like TM2). Get the last freq set
334 * in PERF_CTL.
335 */
Rusty Russelle3f996c2009-06-11 22:59:58 +0930336 rdmsr_on_cpu(cpu, MSR_IA32_PERF_CTL, &l, &h);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 clock_freq = extract_clock(l, cpu, 1);
338 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 return clock_freq;
340}
341
342
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343static int centrino_cpu_init(struct cpufreq_policy *policy)
344{
Mike Travis92cb7612007-10-19 20:35:04 +0200345 struct cpuinfo_x86 *cpu = &cpu_data(policy->cpu);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 unsigned l, h;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 int i;
348
349 /* Only Intel makes Enhanced Speedstep-capable CPUs */
Mike Travisc4762ab2008-07-18 18:11:34 -0700350 if (cpu->x86_vendor != X86_VENDOR_INTEL ||
351 !cpu_has(cpu, X86_FEATURE_EST))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 return -ENODEV;
353
Dave Jones8ad54962006-02-28 00:37:44 -0500354 if (cpu_has(cpu, X86_FEATURE_CONSTANT_TSC))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700355 centrino_driver.flags |= CPUFREQ_CONST_LOOPS;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356
Adrian Bunk68485692007-07-08 23:39:14 +0200357 if (policy->cpu != 0)
358 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700359
Adrian Bunk68485692007-07-08 23:39:14 +0200360 for (i = 0; i < N_IDS; i++)
361 if (centrino_verify_cpu_id(cpu, &cpu_ids[i]))
362 break;
Venkatesh Pallipadif914be72005-08-29 13:54:55 -0700363
Adrian Bunk68485692007-07-08 23:39:14 +0200364 if (i != N_IDS)
Mike Travisc4762ab2008-07-18 18:11:34 -0700365 per_cpu(centrino_cpu, policy->cpu) = &cpu_ids[i];
Venkatesh Pallipadif914be72005-08-29 13:54:55 -0700366
Mike Travisc4762ab2008-07-18 18:11:34 -0700367 if (!per_cpu(centrino_cpu, policy->cpu)) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200368 pr_debug("found unsupported CPU with "
Adrian Bunk68485692007-07-08 23:39:14 +0200369 "Enhanced SpeedStep: send /proc/cpuinfo to "
370 MAINTAINER "\n");
371 return -ENODEV;
372 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373
Evgeny Kapaev7b6f38f2013-10-15 21:42:52 +0400374 if (centrino_cpu_init_table(policy))
Adrian Bunk68485692007-07-08 23:39:14 +0200375 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376
377 /* Check to see if Enhanced SpeedStep is enabled, and try to
378 enable it if not. */
379 rdmsr(MSR_IA32_MISC_ENABLE, l, h);
380
Vegard Nossumecab22a2009-02-20 11:56:38 +0100381 if (!(l & MSR_IA32_MISC_ENABLE_ENHANCED_SPEEDSTEP)) {
382 l |= MSR_IA32_MISC_ENABLE_ENHANCED_SPEEDSTEP;
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200383 pr_debug("trying to enable Enhanced SpeedStep (%x)\n", l);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 wrmsr(MSR_IA32_MISC_ENABLE, l, h);
385
386 /* check to see if it stuck */
387 rdmsr(MSR_IA32_MISC_ENABLE, l, h);
Vegard Nossumecab22a2009-02-20 11:56:38 +0100388 if (!(l & MSR_IA32_MISC_ENABLE_ENHANCED_SPEEDSTEP)) {
Mike Travisc4762ab2008-07-18 18:11:34 -0700389 printk(KERN_INFO PFX
390 "couldn't enable Enhanced SpeedStep\n");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700391 return -ENODEV;
392 }
393 }
394
Mike Travisc4762ab2008-07-18 18:11:34 -0700395 policy->cpuinfo.transition_latency = 10000;
396 /* 10uS transition latency */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397
Viresh Kumar5f3a2d32013-09-16 18:56:38 +0530398 return cpufreq_table_validate_and_show(policy,
Mike Travisc4762ab2008-07-18 18:11:34 -0700399 per_cpu(centrino_model, policy->cpu)->op_points);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400}
401
402static int centrino_cpu_exit(struct cpufreq_policy *policy)
403{
404 unsigned int cpu = policy->cpu;
405
Mike Travisc4762ab2008-07-18 18:11:34 -0700406 if (!per_cpu(centrino_model, cpu))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 return -ENODEV;
408
409 cpufreq_frequency_table_put_attr(cpu);
410
Mike Travisc4762ab2008-07-18 18:11:34 -0700411 per_cpu(centrino_model, cpu) = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412
413 return 0;
414}
415
416/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 * centrino_setpolicy - set a new CPUFreq policy
418 * @policy: new policy
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530419 * @index: index of target frequency
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 *
421 * Sets a new CPUFreq policy.
422 */
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530423static int centrino_target(struct cpufreq_policy *policy, unsigned int index)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424{
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500425 unsigned int msr, oldmsr = 0, h = 0, cpu = policy->cpu;
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500426 int retval = 0;
Viresh Kumard4019f02013-08-14 19:38:24 +0530427 unsigned int j, first_cpu;
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530428 struct cpufreq_frequency_table *op_points;
Rusty Russelle3f996c2009-06-11 22:59:58 +0930429 cpumask_var_t covered_cpus;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430
Rusty Russelle3f996c2009-06-11 22:59:58 +0930431 if (unlikely(!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL)))
Mike Traviseb53fac2008-07-15 14:14:37 -0700432 return -ENOMEM;
433
Mike Travisc4762ab2008-07-18 18:11:34 -0700434 if (unlikely(per_cpu(centrino_model, cpu) == NULL)) {
Mike Traviseb53fac2008-07-15 14:14:37 -0700435 retval = -ENODEV;
436 goto out;
437 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500439 first_cpu = 1;
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530440 op_points = &per_cpu(centrino_model, cpu)->op_points[index];
Rusty Russell835481d2009-01-04 05:18:06 -0800441 for_each_cpu(j, policy->cpus) {
Rusty Russelle3f996c2009-06-11 22:59:58 +0930442 int good_cpu;
Rusty Russell9963d1a2008-11-21 21:07:16 +1030443
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500444 /*
445 * Support for SMP systems.
446 * Make sure we are running on CPU that wants to change freq
447 */
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500448 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
Rusty Russelle3f996c2009-06-11 22:59:58 +0930449 good_cpu = cpumask_any_and(policy->cpus,
450 cpu_online_mask);
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500451 else
Rusty Russelle3f996c2009-06-11 22:59:58 +0930452 good_cpu = j;
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500453
Rusty Russelle3f996c2009-06-11 22:59:58 +0930454 if (good_cpu >= nr_cpu_ids) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200455 pr_debug("couldn't limit to CPUs in this domain\n");
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500456 retval = -EAGAIN;
457 if (first_cpu) {
458 /* We haven't started the transition yet. */
Rusty Russelle3f996c2009-06-11 22:59:58 +0930459 goto out;
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500460 }
461 break;
462 }
463
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530464 msr = op_points->driver_data;
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500465
466 if (first_cpu) {
Rusty Russelle3f996c2009-06-11 22:59:58 +0930467 rdmsr_on_cpu(good_cpu, MSR_IA32_PERF_CTL, &oldmsr, &h);
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500468 if (msr == (oldmsr & 0xffff)) {
Dominik Brodowski2d06d8c2011-03-27 15:04:46 +0200469 pr_debug("no change needed - msr was and needs "
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500470 "to be %x\n", oldmsr);
471 retval = 0;
Rusty Russelle3f996c2009-06-11 22:59:58 +0930472 goto out;
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500473 }
474
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500475 first_cpu = 0;
476 /* all but 16 LSB are reserved, treat them with care */
477 oldmsr &= ~0xffff;
478 msr &= 0xffff;
479 oldmsr |= msr;
480 }
481
Rusty Russelle3f996c2009-06-11 22:59:58 +0930482 wrmsr_on_cpu(good_cpu, MSR_IA32_PERF_CTL, oldmsr, h);
483 if (policy->shared_type == CPUFREQ_SHARED_TYPE_ANY)
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500484 break;
485
Rusty Russelle3f996c2009-06-11 22:59:58 +0930486 cpumask_set_cpu(j, covered_cpus);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 }
488
Venkatesh Pallipadic52851b2005-12-14 15:05:00 -0500489 if (unlikely(retval)) {
490 /*
491 * We have failed halfway through the frequency change.
492 * We have sent callbacks to policy->cpus and
493 * MSRs have already been written on coverd_cpus.
494 * Best effort undo..
495 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496
Rusty Russelle3f996c2009-06-11 22:59:58 +0930497 for_each_cpu(j, covered_cpus)
498 wrmsr_on_cpu(j, MSR_IA32_PERF_CTL, oldmsr, h);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499 }
Mike Traviseb53fac2008-07-15 14:14:37 -0700500 retval = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501
Mike Traviseb53fac2008-07-15 14:14:37 -0700502out:
Rusty Russell5cb05352009-01-04 05:18:05 -0800503 free_cpumask_var(covered_cpus);
Mike Traviseb53fac2008-07-15 14:14:37 -0700504 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505}
506
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507static struct cpufreq_driver centrino_driver = {
508 .name = "centrino", /* should be speedstep-centrino,
509 but there's a 16 char limit */
510 .init = centrino_cpu_init,
511 .exit = centrino_cpu_exit,
Viresh Kumar3be13942013-10-03 20:28:28 +0530512 .verify = cpufreq_generic_frequency_table_verify,
Viresh Kumar9c0ebcf2013-10-25 19:45:48 +0530513 .target_index = centrino_target,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700514 .get = get_cur_freq,
Viresh Kumar3be13942013-10-03 20:28:28 +0530515 .attr = cpufreq_generic_attr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516};
517
Andi Kleenfa8031a2012-01-26 00:09:12 +0100518/*
519 * This doesn't replace the detailed checks above because
520 * the generic CPU IDs don't have a way to match for steppings
521 * or ASCII model IDs.
522 */
523static const struct x86_cpu_id centrino_ids[] = {
524 { X86_VENDOR_INTEL, 6, 9, X86_FEATURE_EST },
525 { X86_VENDOR_INTEL, 6, 13, X86_FEATURE_EST },
526 { X86_VENDOR_INTEL, 6, 13, X86_FEATURE_EST },
527 { X86_VENDOR_INTEL, 6, 13, X86_FEATURE_EST },
528 { X86_VENDOR_INTEL, 15, 3, X86_FEATURE_EST },
529 { X86_VENDOR_INTEL, 15, 4, X86_FEATURE_EST },
530 {}
531};
532#if 0
533/* Autoload or not? Do not for now. */
534MODULE_DEVICE_TABLE(x86cpu, centrino_ids);
535#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536
537/**
538 * centrino_init - initializes the Enhanced SpeedStep CPUFreq driver
539 *
540 * Initializes the Enhanced SpeedStep support. Returns -ENODEV on
541 * unsupported devices, -ENOENT if there's no voltage table for this
542 * particular CPU model, -EINVAL on problems during initiatization,
543 * and zero on success.
544 *
545 * This is quite picky. Not only does the CPU have to advertise the
546 * "est" flag in the cpuid capability flags, we look for a specific
547 * CPU model and stepping, and we need to have the exact model name in
548 * our voltage tables. That is, be paranoid about not releasing
549 * someone's valuable magic smoke.
550 */
551static int __init centrino_init(void)
552{
Andi Kleenfa8031a2012-01-26 00:09:12 +0100553 if (!x86_match_cpu(centrino_ids))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554 return -ENODEV;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700555 return cpufreq_register_driver(&centrino_driver);
556}
557
558static void __exit centrino_exit(void)
559{
560 cpufreq_unregister_driver(&centrino_driver);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561}
562
563MODULE_AUTHOR ("Jeremy Fitzhardinge <jeremy@goop.org>");
564MODULE_DESCRIPTION ("Enhanced SpeedStep driver for Intel Pentium M processors.");
565MODULE_LICENSE ("GPL");
566
567late_initcall(centrino_init);
568module_exit(centrino_exit);