cpufreq: acpi-cpufreq: Make read and write operations more efficient
[linux-2.6-block.git] / drivers / cpufreq / acpi-cpufreq.c
1 /*
2  * acpi-cpufreq.c - ACPI Processor P-States Driver
3  *
4  *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
5  *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
6  *  Copyright (C) 2002 - 2004 Dominik Brodowski <linux@brodo.de>
7  *  Copyright (C) 2006       Denis Sadykov <denis.m.sadykov@intel.com>
8  *
9  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
10  *
11  *  This program is free software; you can redistribute it and/or modify
12  *  it under the terms of the GNU General Public License as published by
13  *  the Free Software Foundation; either version 2 of the License, or (at
14  *  your option) any later version.
15  *
16  *  This program is distributed in the hope that it will be useful, but
17  *  WITHOUT ANY WARRANTY; without even the implied warranty of
18  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  *  General Public License for more details.
20  *
21  *  You should have received a copy of the GNU General Public License along
22  *  with this program; if not, write to the Free Software Foundation, Inc.,
23  *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
24  *
25  * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
26  */
27
28 #include <linux/kernel.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/smp.h>
32 #include <linux/sched.h>
33 #include <linux/cpufreq.h>
34 #include <linux/compiler.h>
35 #include <linux/dmi.h>
36 #include <linux/slab.h>
37
38 #include <linux/acpi.h>
39 #include <linux/io.h>
40 #include <linux/delay.h>
41 #include <linux/uaccess.h>
42
43 #include <acpi/processor.h>
44
45 #include <asm/msr.h>
46 #include <asm/processor.h>
47 #include <asm/cpufeature.h>
48
49 MODULE_AUTHOR("Paul Diefenbaugh, Dominik Brodowski");
50 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
51 MODULE_LICENSE("GPL");
52
53 #define PFX "acpi-cpufreq: "
54
55 enum {
56         UNDEFINED_CAPABLE = 0,
57         SYSTEM_INTEL_MSR_CAPABLE,
58         SYSTEM_AMD_MSR_CAPABLE,
59         SYSTEM_IO_CAPABLE,
60 };
61
62 #define INTEL_MSR_RANGE         (0xffff)
63 #define AMD_MSR_RANGE           (0x7)
64
65 #define MSR_K7_HWCR_CPB_DIS     (1ULL << 25)
66
67 struct acpi_cpufreq_data {
68         struct cpufreq_frequency_table *freq_table;
69         unsigned int resume;
70         unsigned int cpu_feature;
71         unsigned int acpi_perf_cpu;
72         cpumask_var_t freqdomain_cpus;
73         void (*cpu_freq_write)(struct acpi_pct_register *reg, u32 val);
74         u32 (*cpu_freq_read)(struct acpi_pct_register *reg);
75 };
76
77 /* acpi_perf_data is a pointer to percpu data. */
78 static struct acpi_processor_performance __percpu *acpi_perf_data;
79
80 static inline struct acpi_processor_performance *to_perf_data(struct acpi_cpufreq_data *data)
81 {
82         return per_cpu_ptr(acpi_perf_data, data->acpi_perf_cpu);
83 }
84
85 static struct cpufreq_driver acpi_cpufreq_driver;
86
87 static unsigned int acpi_pstate_strict;
88 static struct msr __percpu *msrs;
89
90 static bool boost_state(unsigned int cpu)
91 {
92         u32 lo, hi;
93         u64 msr;
94
95         switch (boot_cpu_data.x86_vendor) {
96         case X86_VENDOR_INTEL:
97                 rdmsr_on_cpu(cpu, MSR_IA32_MISC_ENABLE, &lo, &hi);
98                 msr = lo | ((u64)hi << 32);
99                 return !(msr & MSR_IA32_MISC_ENABLE_TURBO_DISABLE);
100         case X86_VENDOR_AMD:
101                 rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
102                 msr = lo | ((u64)hi << 32);
103                 return !(msr & MSR_K7_HWCR_CPB_DIS);
104         }
105         return false;
106 }
107
108 static void boost_set_msrs(bool enable, const struct cpumask *cpumask)
109 {
110         u32 cpu;
111         u32 msr_addr;
112         u64 msr_mask;
113
114         switch (boot_cpu_data.x86_vendor) {
115         case X86_VENDOR_INTEL:
116                 msr_addr = MSR_IA32_MISC_ENABLE;
117                 msr_mask = MSR_IA32_MISC_ENABLE_TURBO_DISABLE;
118                 break;
119         case X86_VENDOR_AMD:
120                 msr_addr = MSR_K7_HWCR;
121                 msr_mask = MSR_K7_HWCR_CPB_DIS;
122                 break;
123         default:
124                 return;
125         }
126
127         rdmsr_on_cpus(cpumask, msr_addr, msrs);
128
129         for_each_cpu(cpu, cpumask) {
130                 struct msr *reg = per_cpu_ptr(msrs, cpu);
131                 if (enable)
132                         reg->q &= ~msr_mask;
133                 else
134                         reg->q |= msr_mask;
135         }
136
137         wrmsr_on_cpus(cpumask, msr_addr, msrs);
138 }
139
140 static int set_boost(int val)
141 {
142         get_online_cpus();
143         boost_set_msrs(val, cpu_online_mask);
144         put_online_cpus();
145         pr_debug("Core Boosting %sabled.\n", val ? "en" : "dis");
146
147         return 0;
148 }
149
150 static ssize_t show_freqdomain_cpus(struct cpufreq_policy *policy, char *buf)
151 {
152         struct acpi_cpufreq_data *data = policy->driver_data;
153
154         if (unlikely(!data))
155                 return -ENODEV;
156
157         return cpufreq_show_cpus(data->freqdomain_cpus, buf);
158 }
159
160 cpufreq_freq_attr_ro(freqdomain_cpus);
161
162 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
163 static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
164                          size_t count)
165 {
166         int ret;
167         unsigned int val = 0;
168
169         if (!acpi_cpufreq_driver.set_boost)
170                 return -EINVAL;
171
172         ret = kstrtouint(buf, 10, &val);
173         if (ret || val > 1)
174                 return -EINVAL;
175
176         set_boost(val);
177
178         return count;
179 }
180
181 static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf)
182 {
183         return sprintf(buf, "%u\n", acpi_cpufreq_driver.boost_enabled);
184 }
185
186 cpufreq_freq_attr_rw(cpb);
187 #endif
188
189 static int check_est_cpu(unsigned int cpuid)
190 {
191         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
192
193         return cpu_has(cpu, X86_FEATURE_EST);
194 }
195
196 static int check_amd_hwpstate_cpu(unsigned int cpuid)
197 {
198         struct cpuinfo_x86 *cpu = &cpu_data(cpuid);
199
200         return cpu_has(cpu, X86_FEATURE_HW_PSTATE);
201 }
202
203 static unsigned extract_io(u32 value, struct acpi_cpufreq_data *data)
204 {
205         struct acpi_processor_performance *perf;
206         int i;
207
208         perf = to_perf_data(data);
209
210         for (i = 0; i < perf->state_count; i++) {
211                 if (value == perf->states[i].status)
212                         return data->freq_table[i].frequency;
213         }
214         return 0;
215 }
216
217 static unsigned extract_msr(u32 msr, struct acpi_cpufreq_data *data)
218 {
219         struct cpufreq_frequency_table *pos;
220         struct acpi_processor_performance *perf;
221
222         if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
223                 msr &= AMD_MSR_RANGE;
224         else
225                 msr &= INTEL_MSR_RANGE;
226
227         perf = to_perf_data(data);
228
229         cpufreq_for_each_entry(pos, data->freq_table)
230                 if (msr == perf->states[pos->driver_data].status)
231                         return pos->frequency;
232         return data->freq_table[0].frequency;
233 }
234
235 static unsigned extract_freq(u32 val, struct acpi_cpufreq_data *data)
236 {
237         switch (data->cpu_feature) {
238         case SYSTEM_INTEL_MSR_CAPABLE:
239         case SYSTEM_AMD_MSR_CAPABLE:
240                 return extract_msr(val, data);
241         case SYSTEM_IO_CAPABLE:
242                 return extract_io(val, data);
243         default:
244                 return 0;
245         }
246 }
247
248 u32 cpu_freq_read_intel(struct acpi_pct_register *not_used)
249 {
250         u32 val, dummy;
251
252         rdmsr(MSR_IA32_PERF_CTL, val, dummy);
253         return val;
254 }
255
256 void cpu_freq_write_intel(struct acpi_pct_register *not_used, u32 val)
257 {
258         u32 lo, hi;
259
260         rdmsr(MSR_IA32_PERF_CTL, lo, hi);
261         lo = (lo & ~INTEL_MSR_RANGE) | (val & INTEL_MSR_RANGE);
262         wrmsr(MSR_IA32_PERF_CTL, lo, hi);
263 }
264
265 u32 cpu_freq_read_amd(struct acpi_pct_register *not_used)
266 {
267         u32 val, dummy;
268
269         rdmsr(MSR_AMD_PERF_CTL, val, dummy);
270         return val;
271 }
272
273 void cpu_freq_write_amd(struct acpi_pct_register *not_used, u32 val)
274 {
275         wrmsr(MSR_AMD_PERF_CTL, val, 0);
276 }
277
278 u32 cpu_freq_read_io(struct acpi_pct_register *reg)
279 {
280         u32 val;
281
282         acpi_os_read_port(reg->address, &val, reg->bit_width);
283         return val;
284 }
285
286 void cpu_freq_write_io(struct acpi_pct_register *reg, u32 val)
287 {
288         acpi_os_write_port(reg->address, val, reg->bit_width);
289 }
290
291 struct drv_cmd {
292         struct acpi_pct_register *reg;
293         u32 val;
294         union {
295                 void (*write)(struct acpi_pct_register *reg, u32 val);
296                 u32 (*read)(struct acpi_pct_register *reg);
297         } func;
298 };
299
300 /* Called via smp_call_function_single(), on the target CPU */
301 static void do_drv_read(void *_cmd)
302 {
303         struct drv_cmd *cmd = _cmd;
304
305         cmd->val = cmd->func.read(cmd->reg);
306 }
307
308 static u32 drv_read(struct acpi_cpufreq_data *data, const struct cpumask *mask)
309 {
310         struct acpi_processor_performance *perf = to_perf_data(data);
311         struct drv_cmd cmd = {
312                 .reg = &perf->control_register,
313                 .func.read = data->cpu_freq_read,
314         };
315         int err;
316
317         err = smp_call_function_any(mask, do_drv_read, &cmd, 1);
318         WARN_ON_ONCE(err);      /* smp_call_function_any() was buggy? */
319         return cmd.val;
320 }
321
322 /* Called via smp_call_function_many(), on the target CPUs */
323 static void do_drv_write(void *_cmd)
324 {
325         struct drv_cmd *cmd = _cmd;
326
327         cmd->func.write(cmd->reg, cmd->val);
328 }
329
330 static void drv_write(struct acpi_cpufreq_data *data,
331                       const struct cpumask *mask, u32 val)
332 {
333         struct acpi_processor_performance *perf = to_perf_data(data);
334         struct drv_cmd cmd = {
335                 .reg = &perf->control_register,
336                 .val = val,
337                 .func.write = data->cpu_freq_write,
338         };
339         int this_cpu;
340
341         this_cpu = get_cpu();
342         if (cpumask_test_cpu(this_cpu, mask))
343                 do_drv_write(&cmd);
344
345         smp_call_function_many(mask, do_drv_write, &cmd, 1);
346         put_cpu();
347 }
348
349 static u32 get_cur_val(const struct cpumask *mask, struct acpi_cpufreq_data *data)
350 {
351         u32 val;
352
353         if (unlikely(cpumask_empty(mask)))
354                 return 0;
355
356         val = drv_read(data, mask);
357
358         pr_debug("get_cur_val = %u\n", val);
359
360         return val;
361 }
362
363 static unsigned int get_cur_freq_on_cpu(unsigned int cpu)
364 {
365         struct acpi_cpufreq_data *data;
366         struct cpufreq_policy *policy;
367         unsigned int freq;
368         unsigned int cached_freq;
369
370         pr_debug("get_cur_freq_on_cpu (%d)\n", cpu);
371
372         policy = cpufreq_cpu_get_raw(cpu);
373         if (unlikely(!policy))
374                 return 0;
375
376         data = policy->driver_data;
377         if (unlikely(!data || !data->freq_table))
378                 return 0;
379
380         cached_freq = data->freq_table[to_perf_data(data)->state].frequency;
381         freq = extract_freq(get_cur_val(cpumask_of(cpu), data), data);
382         if (freq != cached_freq) {
383                 /*
384                  * The dreaded BIOS frequency change behind our back.
385                  * Force set the frequency on next target call.
386                  */
387                 data->resume = 1;
388         }
389
390         pr_debug("cur freq = %u\n", freq);
391
392         return freq;
393 }
394
395 static unsigned int check_freqs(const struct cpumask *mask, unsigned int freq,
396                                 struct acpi_cpufreq_data *data)
397 {
398         unsigned int cur_freq;
399         unsigned int i;
400
401         for (i = 0; i < 100; i++) {
402                 cur_freq = extract_freq(get_cur_val(mask, data), data);
403                 if (cur_freq == freq)
404                         return 1;
405                 udelay(10);
406         }
407         return 0;
408 }
409
410 static int acpi_cpufreq_target(struct cpufreq_policy *policy,
411                                unsigned int index)
412 {
413         struct acpi_cpufreq_data *data = policy->driver_data;
414         struct acpi_processor_performance *perf;
415         const struct cpumask *mask;
416         unsigned int next_perf_state = 0; /* Index into perf table */
417         int result = 0;
418
419         if (unlikely(data == NULL || data->freq_table == NULL)) {
420                 return -ENODEV;
421         }
422
423         perf = to_perf_data(data);
424         next_perf_state = data->freq_table[index].driver_data;
425         if (perf->state == next_perf_state) {
426                 if (unlikely(data->resume)) {
427                         pr_debug("Called after resume, resetting to P%d\n",
428                                 next_perf_state);
429                         data->resume = 0;
430                 } else {
431                         pr_debug("Already at target state (P%d)\n",
432                                 next_perf_state);
433                         return 0;
434                 }
435         }
436
437         /*
438          * The core won't allow CPUs to go away until the governor has been
439          * stopped, so we can rely on the stability of policy->cpus.
440          */
441         mask = policy->shared_type == CPUFREQ_SHARED_TYPE_ANY ?
442                 cpumask_of(policy->cpu) : policy->cpus;
443
444         drv_write(data, mask, perf->states[next_perf_state].control);
445
446         if (acpi_pstate_strict) {
447                 if (!check_freqs(mask, data->freq_table[index].frequency,
448                                         data)) {
449                         pr_debug("acpi_cpufreq_target failed (%d)\n",
450                                 policy->cpu);
451                         result = -EAGAIN;
452                 }
453         }
454
455         if (!result)
456                 perf->state = next_perf_state;
457
458         return result;
459 }
460
461 static unsigned long
462 acpi_cpufreq_guess_freq(struct acpi_cpufreq_data *data, unsigned int cpu)
463 {
464         struct acpi_processor_performance *perf;
465
466         perf = to_perf_data(data);
467         if (cpu_khz) {
468                 /* search the closest match to cpu_khz */
469                 unsigned int i;
470                 unsigned long freq;
471                 unsigned long freqn = perf->states[0].core_frequency * 1000;
472
473                 for (i = 0; i < (perf->state_count-1); i++) {
474                         freq = freqn;
475                         freqn = perf->states[i+1].core_frequency * 1000;
476                         if ((2 * cpu_khz) > (freqn + freq)) {
477                                 perf->state = i;
478                                 return freq;
479                         }
480                 }
481                 perf->state = perf->state_count-1;
482                 return freqn;
483         } else {
484                 /* assume CPU is at P0... */
485                 perf->state = 0;
486                 return perf->states[0].core_frequency * 1000;
487         }
488 }
489
490 static void free_acpi_perf_data(void)
491 {
492         unsigned int i;
493
494         /* Freeing a NULL pointer is OK, and alloc_percpu zeroes. */
495         for_each_possible_cpu(i)
496                 free_cpumask_var(per_cpu_ptr(acpi_perf_data, i)
497                                  ->shared_cpu_map);
498         free_percpu(acpi_perf_data);
499 }
500
501 static int boost_notify(struct notifier_block *nb, unsigned long action,
502                       void *hcpu)
503 {
504         unsigned cpu = (long)hcpu;
505         const struct cpumask *cpumask;
506
507         cpumask = get_cpu_mask(cpu);
508
509         /*
510          * Clear the boost-disable bit on the CPU_DOWN path so that
511          * this cpu cannot block the remaining ones from boosting. On
512          * the CPU_UP path we simply keep the boost-disable flag in
513          * sync with the current global state.
514          */
515
516         switch (action) {
517         case CPU_UP_PREPARE:
518         case CPU_UP_PREPARE_FROZEN:
519                 boost_set_msrs(acpi_cpufreq_driver.boost_enabled, cpumask);
520                 break;
521
522         case CPU_DOWN_PREPARE:
523         case CPU_DOWN_PREPARE_FROZEN:
524                 boost_set_msrs(1, cpumask);
525                 break;
526
527         default:
528                 break;
529         }
530
531         return NOTIFY_OK;
532 }
533
534
535 static struct notifier_block boost_nb = {
536         .notifier_call          = boost_notify,
537 };
538
539 /*
540  * acpi_cpufreq_early_init - initialize ACPI P-States library
541  *
542  * Initialize the ACPI P-States library (drivers/acpi/processor_perflib.c)
543  * in order to determine correct frequency and voltage pairings. We can
544  * do _PDC and _PSD and find out the processor dependency for the
545  * actual init that will happen later...
546  */
547 static int __init acpi_cpufreq_early_init(void)
548 {
549         unsigned int i;
550         pr_debug("acpi_cpufreq_early_init\n");
551
552         acpi_perf_data = alloc_percpu(struct acpi_processor_performance);
553         if (!acpi_perf_data) {
554                 pr_debug("Memory allocation error for acpi_perf_data.\n");
555                 return -ENOMEM;
556         }
557         for_each_possible_cpu(i) {
558                 if (!zalloc_cpumask_var_node(
559                         &per_cpu_ptr(acpi_perf_data, i)->shared_cpu_map,
560                         GFP_KERNEL, cpu_to_node(i))) {
561
562                         /* Freeing a NULL pointer is OK: alloc_percpu zeroes. */
563                         free_acpi_perf_data();
564                         return -ENOMEM;
565                 }
566         }
567
568         /* Do initialization in ACPI core */
569         acpi_processor_preregister_performance(acpi_perf_data);
570         return 0;
571 }
572
573 #ifdef CONFIG_SMP
574 /*
575  * Some BIOSes do SW_ANY coordination internally, either set it up in hw
576  * or do it in BIOS firmware and won't inform about it to OS. If not
577  * detected, this has a side effect of making CPU run at a different speed
578  * than OS intended it to run at. Detect it and handle it cleanly.
579  */
580 static int bios_with_sw_any_bug;
581
582 static int sw_any_bug_found(const struct dmi_system_id *d)
583 {
584         bios_with_sw_any_bug = 1;
585         return 0;
586 }
587
588 static const struct dmi_system_id sw_any_bug_dmi_table[] = {
589         {
590                 .callback = sw_any_bug_found,
591                 .ident = "Supermicro Server X6DLP",
592                 .matches = {
593                         DMI_MATCH(DMI_SYS_VENDOR, "Supermicro"),
594                         DMI_MATCH(DMI_BIOS_VERSION, "080010"),
595                         DMI_MATCH(DMI_PRODUCT_NAME, "X6DLP"),
596                 },
597         },
598         { }
599 };
600
601 static int acpi_cpufreq_blacklist(struct cpuinfo_x86 *c)
602 {
603         /* Intel Xeon Processor 7100 Series Specification Update
604          * http://www.intel.com/Assets/PDF/specupdate/314554.pdf
605          * AL30: A Machine Check Exception (MCE) Occurring during an
606          * Enhanced Intel SpeedStep Technology Ratio Change May Cause
607          * Both Processor Cores to Lock Up. */
608         if (c->x86_vendor == X86_VENDOR_INTEL) {
609                 if ((c->x86 == 15) &&
610                     (c->x86_model == 6) &&
611                     (c->x86_mask == 8)) {
612                         printk(KERN_INFO "acpi-cpufreq: Intel(R) "
613                             "Xeon(R) 7100 Errata AL30, processors may "
614                             "lock up on frequency changes: disabling "
615                             "acpi-cpufreq.\n");
616                         return -ENODEV;
617                     }
618                 }
619         return 0;
620 }
621 #endif
622
623 static int acpi_cpufreq_cpu_init(struct cpufreq_policy *policy)
624 {
625         unsigned int i;
626         unsigned int valid_states = 0;
627         unsigned int cpu = policy->cpu;
628         struct acpi_cpufreq_data *data;
629         unsigned int result = 0;
630         struct cpuinfo_x86 *c = &cpu_data(policy->cpu);
631         struct acpi_processor_performance *perf;
632 #ifdef CONFIG_SMP
633         static int blacklisted;
634 #endif
635
636         pr_debug("acpi_cpufreq_cpu_init\n");
637
638 #ifdef CONFIG_SMP
639         if (blacklisted)
640                 return blacklisted;
641         blacklisted = acpi_cpufreq_blacklist(c);
642         if (blacklisted)
643                 return blacklisted;
644 #endif
645
646         data = kzalloc(sizeof(*data), GFP_KERNEL);
647         if (!data)
648                 return -ENOMEM;
649
650         if (!zalloc_cpumask_var(&data->freqdomain_cpus, GFP_KERNEL)) {
651                 result = -ENOMEM;
652                 goto err_free;
653         }
654
655         perf = per_cpu_ptr(acpi_perf_data, cpu);
656         data->acpi_perf_cpu = cpu;
657         policy->driver_data = data;
658
659         if (cpu_has(c, X86_FEATURE_CONSTANT_TSC))
660                 acpi_cpufreq_driver.flags |= CPUFREQ_CONST_LOOPS;
661
662         result = acpi_processor_register_performance(perf, cpu);
663         if (result)
664                 goto err_free_mask;
665
666         policy->shared_type = perf->shared_type;
667
668         /*
669          * Will let policy->cpus know about dependency only when software
670          * coordination is required.
671          */
672         if (policy->shared_type == CPUFREQ_SHARED_TYPE_ALL ||
673             policy->shared_type == CPUFREQ_SHARED_TYPE_ANY) {
674                 cpumask_copy(policy->cpus, perf->shared_cpu_map);
675         }
676         cpumask_copy(data->freqdomain_cpus, perf->shared_cpu_map);
677
678 #ifdef CONFIG_SMP
679         dmi_check_system(sw_any_bug_dmi_table);
680         if (bios_with_sw_any_bug && !policy_is_shared(policy)) {
681                 policy->shared_type = CPUFREQ_SHARED_TYPE_ALL;
682                 cpumask_copy(policy->cpus, topology_core_cpumask(cpu));
683         }
684
685         if (check_amd_hwpstate_cpu(cpu) && !acpi_pstate_strict) {
686                 cpumask_clear(policy->cpus);
687                 cpumask_set_cpu(cpu, policy->cpus);
688                 cpumask_copy(data->freqdomain_cpus,
689                              topology_sibling_cpumask(cpu));
690                 policy->shared_type = CPUFREQ_SHARED_TYPE_HW;
691                 pr_info_once(PFX "overriding BIOS provided _PSD data\n");
692         }
693 #endif
694
695         /* capability check */
696         if (perf->state_count <= 1) {
697                 pr_debug("No P-States\n");
698                 result = -ENODEV;
699                 goto err_unreg;
700         }
701
702         if (perf->control_register.space_id != perf->status_register.space_id) {
703                 result = -ENODEV;
704                 goto err_unreg;
705         }
706
707         switch (perf->control_register.space_id) {
708         case ACPI_ADR_SPACE_SYSTEM_IO:
709                 if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
710                     boot_cpu_data.x86 == 0xf) {
711                         pr_debug("AMD K8 systems must use native drivers.\n");
712                         result = -ENODEV;
713                         goto err_unreg;
714                 }
715                 pr_debug("SYSTEM IO addr space\n");
716                 data->cpu_feature = SYSTEM_IO_CAPABLE;
717                 data->cpu_freq_read = cpu_freq_read_io;
718                 data->cpu_freq_write = cpu_freq_write_io;
719                 break;
720         case ACPI_ADR_SPACE_FIXED_HARDWARE:
721                 pr_debug("HARDWARE addr space\n");
722                 if (check_est_cpu(cpu)) {
723                         data->cpu_feature = SYSTEM_INTEL_MSR_CAPABLE;
724                         data->cpu_freq_read = cpu_freq_read_intel;
725                         data->cpu_freq_write = cpu_freq_write_intel;
726                         break;
727                 }
728                 if (check_amd_hwpstate_cpu(cpu)) {
729                         data->cpu_feature = SYSTEM_AMD_MSR_CAPABLE;
730                         data->cpu_freq_read = cpu_freq_read_amd;
731                         data->cpu_freq_write = cpu_freq_write_amd;
732                         break;
733                 }
734                 result = -ENODEV;
735                 goto err_unreg;
736         default:
737                 pr_debug("Unknown addr space %d\n",
738                         (u32) (perf->control_register.space_id));
739                 result = -ENODEV;
740                 goto err_unreg;
741         }
742
743         data->freq_table = kzalloc(sizeof(*data->freq_table) *
744                     (perf->state_count+1), GFP_KERNEL);
745         if (!data->freq_table) {
746                 result = -ENOMEM;
747                 goto err_unreg;
748         }
749
750         /* detect transition latency */
751         policy->cpuinfo.transition_latency = 0;
752         for (i = 0; i < perf->state_count; i++) {
753                 if ((perf->states[i].transition_latency * 1000) >
754                     policy->cpuinfo.transition_latency)
755                         policy->cpuinfo.transition_latency =
756                             perf->states[i].transition_latency * 1000;
757         }
758
759         /* Check for high latency (>20uS) from buggy BIOSes, like on T42 */
760         if (perf->control_register.space_id == ACPI_ADR_SPACE_FIXED_HARDWARE &&
761             policy->cpuinfo.transition_latency > 20 * 1000) {
762                 policy->cpuinfo.transition_latency = 20 * 1000;
763                 printk_once(KERN_INFO
764                             "P-state transition latency capped at 20 uS\n");
765         }
766
767         /* table init */
768         for (i = 0; i < perf->state_count; i++) {
769                 if (i > 0 && perf->states[i].core_frequency >=
770                     data->freq_table[valid_states-1].frequency / 1000)
771                         continue;
772
773                 data->freq_table[valid_states].driver_data = i;
774                 data->freq_table[valid_states].frequency =
775                     perf->states[i].core_frequency * 1000;
776                 valid_states++;
777         }
778         data->freq_table[valid_states].frequency = CPUFREQ_TABLE_END;
779         perf->state = 0;
780
781         result = cpufreq_table_validate_and_show(policy, data->freq_table);
782         if (result)
783                 goto err_freqfree;
784
785         if (perf->states[0].core_frequency * 1000 != policy->cpuinfo.max_freq)
786                 printk(KERN_WARNING FW_WARN "P-state 0 is not max freq\n");
787
788         switch (perf->control_register.space_id) {
789         case ACPI_ADR_SPACE_SYSTEM_IO:
790                 /*
791                  * The core will not set policy->cur, because
792                  * cpufreq_driver->get is NULL, so we need to set it here.
793                  * However, we have to guess it, because the current speed is
794                  * unknown and not detectable via IO ports.
795                  */
796                 policy->cur = acpi_cpufreq_guess_freq(data, policy->cpu);
797                 break;
798         case ACPI_ADR_SPACE_FIXED_HARDWARE:
799                 acpi_cpufreq_driver.get = get_cur_freq_on_cpu;
800                 break;
801         default:
802                 break;
803         }
804
805         /* notify BIOS that we exist */
806         acpi_processor_notify_smm(THIS_MODULE);
807
808         pr_debug("CPU%u - ACPI performance management activated.\n", cpu);
809         for (i = 0; i < perf->state_count; i++)
810                 pr_debug("     %cP%d: %d MHz, %d mW, %d uS\n",
811                         (i == perf->state ? '*' : ' '), i,
812                         (u32) perf->states[i].core_frequency,
813                         (u32) perf->states[i].power,
814                         (u32) perf->states[i].transition_latency);
815
816         /*
817          * the first call to ->target() should result in us actually
818          * writing something to the appropriate registers.
819          */
820         data->resume = 1;
821
822         return result;
823
824 err_freqfree:
825         kfree(data->freq_table);
826 err_unreg:
827         acpi_processor_unregister_performance(cpu);
828 err_free_mask:
829         free_cpumask_var(data->freqdomain_cpus);
830 err_free:
831         kfree(data);
832         policy->driver_data = NULL;
833
834         return result;
835 }
836
837 static int acpi_cpufreq_cpu_exit(struct cpufreq_policy *policy)
838 {
839         struct acpi_cpufreq_data *data = policy->driver_data;
840
841         pr_debug("acpi_cpufreq_cpu_exit\n");
842
843         if (data) {
844                 policy->driver_data = NULL;
845                 acpi_processor_unregister_performance(data->acpi_perf_cpu);
846                 free_cpumask_var(data->freqdomain_cpus);
847                 kfree(data->freq_table);
848                 kfree(data);
849         }
850
851         return 0;
852 }
853
854 static int acpi_cpufreq_resume(struct cpufreq_policy *policy)
855 {
856         struct acpi_cpufreq_data *data = policy->driver_data;
857
858         pr_debug("acpi_cpufreq_resume\n");
859
860         data->resume = 1;
861
862         return 0;
863 }
864
865 static struct freq_attr *acpi_cpufreq_attr[] = {
866         &cpufreq_freq_attr_scaling_available_freqs,
867         &freqdomain_cpus,
868 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
869         &cpb,
870 #endif
871         NULL,
872 };
873
874 static struct cpufreq_driver acpi_cpufreq_driver = {
875         .verify         = cpufreq_generic_frequency_table_verify,
876         .target_index   = acpi_cpufreq_target,
877         .bios_limit     = acpi_processor_get_bios_limit,
878         .init           = acpi_cpufreq_cpu_init,
879         .exit           = acpi_cpufreq_cpu_exit,
880         .resume         = acpi_cpufreq_resume,
881         .name           = "acpi-cpufreq",
882         .attr           = acpi_cpufreq_attr,
883 };
884
885 static void __init acpi_cpufreq_boost_init(void)
886 {
887         if (boot_cpu_has(X86_FEATURE_CPB) || boot_cpu_has(X86_FEATURE_IDA)) {
888                 msrs = msrs_alloc();
889
890                 if (!msrs)
891                         return;
892
893                 acpi_cpufreq_driver.set_boost = set_boost;
894                 acpi_cpufreq_driver.boost_enabled = boost_state(0);
895
896                 cpu_notifier_register_begin();
897
898                 /* Force all MSRs to the same value */
899                 boost_set_msrs(acpi_cpufreq_driver.boost_enabled,
900                                cpu_online_mask);
901
902                 __register_cpu_notifier(&boost_nb);
903
904                 cpu_notifier_register_done();
905         }
906 }
907
908 static void acpi_cpufreq_boost_exit(void)
909 {
910         if (msrs) {
911                 unregister_cpu_notifier(&boost_nb);
912
913                 msrs_free(msrs);
914                 msrs = NULL;
915         }
916 }
917
918 static int __init acpi_cpufreq_init(void)
919 {
920         int ret;
921
922         if (acpi_disabled)
923                 return -ENODEV;
924
925         /* don't keep reloading if cpufreq_driver exists */
926         if (cpufreq_get_current_driver())
927                 return -EEXIST;
928
929         pr_debug("acpi_cpufreq_init\n");
930
931         ret = acpi_cpufreq_early_init();
932         if (ret)
933                 return ret;
934
935 #ifdef CONFIG_X86_ACPI_CPUFREQ_CPB
936         /* this is a sysfs file with a strange name and an even stranger
937          * semantic - per CPU instantiation, but system global effect.
938          * Lets enable it only on AMD CPUs for compatibility reasons and
939          * only if configured. This is considered legacy code, which
940          * will probably be removed at some point in the future.
941          */
942         if (!check_amd_hwpstate_cpu(0)) {
943                 struct freq_attr **attr;
944
945                 pr_debug("CPB unsupported, do not expose it\n");
946
947                 for (attr = acpi_cpufreq_attr; *attr; attr++)
948                         if (*attr == &cpb) {
949                                 *attr = NULL;
950                                 break;
951                         }
952         }
953 #endif
954         acpi_cpufreq_boost_init();
955
956         ret = cpufreq_register_driver(&acpi_cpufreq_driver);
957         if (ret) {
958                 free_acpi_perf_data();
959                 acpi_cpufreq_boost_exit();
960         }
961         return ret;
962 }
963
964 static void __exit acpi_cpufreq_exit(void)
965 {
966         pr_debug("acpi_cpufreq_exit\n");
967
968         acpi_cpufreq_boost_exit();
969
970         cpufreq_unregister_driver(&acpi_cpufreq_driver);
971
972         free_acpi_perf_data();
973 }
974
975 module_param(acpi_pstate_strict, uint, 0644);
976 MODULE_PARM_DESC(acpi_pstate_strict,
977         "value 0 or non-zero. non-zero -> strict ACPI checks are "
978         "performed during frequency changes.");
979
980 late_initcall(acpi_cpufreq_init);
981 module_exit(acpi_cpufreq_exit);
982
983 static const struct x86_cpu_id acpi_cpufreq_ids[] = {
984         X86_FEATURE_MATCH(X86_FEATURE_ACPI),
985         X86_FEATURE_MATCH(X86_FEATURE_HW_PSTATE),
986         {}
987 };
988 MODULE_DEVICE_TABLE(x86cpu, acpi_cpufreq_ids);
989
990 static const struct acpi_device_id processor_device_ids[] = {
991         {ACPI_PROCESSOR_OBJECT_HID, },
992         {ACPI_PROCESSOR_DEVICE_HID, },
993         {},
994 };
995 MODULE_DEVICE_TABLE(acpi, processor_device_ids);
996
997 MODULE_ALIAS("acpi");