Pull altix-mmr into release branch
[linux-2.6] / drivers / cpufreq / cpufreq.c
1 /*
2  *  linux/drivers/cpufreq/cpufreq.c
3  *
4  *  Copyright (C) 2001 Russell King
5  *            (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  *
11  */
12
13 #include <linux/config.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/notifier.h>
18 #include <linux/cpufreq.h>
19 #include <linux/delay.h>
20 #include <linux/interrupt.h>
21 #include <linux/spinlock.h>
22 #include <linux/device.h>
23 #include <linux/slab.h>
24 #include <linux/cpu.h>
25 #include <linux/completion.h>
26
27 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_CORE, "cpufreq-core", msg)
28
29 /**
30  * The "cpufreq driver" - the arch- or hardware-dependend low
31  * level driver of CPUFreq support, and its spinlock. This lock
32  * also protects the cpufreq_cpu_data array.
33  */
34 static struct cpufreq_driver    *cpufreq_driver;
35 static struct cpufreq_policy    *cpufreq_cpu_data[NR_CPUS];
36 static DEFINE_SPINLOCK(cpufreq_driver_lock);
37
38
39 /* we keep a copy of all ->add'ed CPU's struct sys_device here;
40  * as it is only accessed in ->add and ->remove, no lock or reference
41  * count is necessary.
42  */
43 static struct sys_device        *cpu_sys_devices[NR_CPUS];
44
45
46 /* internal prototypes */
47 static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event);
48 static void handle_update(void *data);
49 static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci);
50
51 /**
52  * Two notifier lists: the "policy" list is involved in the 
53  * validation process for a new CPU frequency policy; the 
54  * "transition" list for kernel code that needs to handle
55  * changes to devices when the CPU clock speed changes.
56  * The mutex locks both lists.
57  */
58 static struct notifier_block    *cpufreq_policy_notifier_list;
59 static struct notifier_block    *cpufreq_transition_notifier_list;
60 static DECLARE_RWSEM            (cpufreq_notifier_rwsem);
61
62
63 static LIST_HEAD(cpufreq_governor_list);
64 static DECLARE_MUTEX            (cpufreq_governor_sem);
65
66 struct cpufreq_policy * cpufreq_cpu_get(unsigned int cpu)
67 {
68         struct cpufreq_policy *data;
69         unsigned long flags;
70
71         if (cpu >= NR_CPUS)
72                 goto err_out;
73
74         /* get the cpufreq driver */
75         spin_lock_irqsave(&cpufreq_driver_lock, flags);
76
77         if (!cpufreq_driver)
78                 goto err_out_unlock;
79
80         if (!try_module_get(cpufreq_driver->owner))
81                 goto err_out_unlock;
82
83
84         /* get the CPU */
85         data = cpufreq_cpu_data[cpu];
86
87         if (!data)
88                 goto err_out_put_module;
89
90         if (!kobject_get(&data->kobj))
91                 goto err_out_put_module;
92
93
94         spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
95
96         return data;
97
98  err_out_put_module:
99         module_put(cpufreq_driver->owner);
100  err_out_unlock:
101         spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
102  err_out:
103         return NULL;
104 }
105 EXPORT_SYMBOL_GPL(cpufreq_cpu_get);
106
107 void cpufreq_cpu_put(struct cpufreq_policy *data)
108 {
109         kobject_put(&data->kobj);
110         module_put(cpufreq_driver->owner);
111 }
112 EXPORT_SYMBOL_GPL(cpufreq_cpu_put);
113
114
115 /*********************************************************************
116  *                     UNIFIED DEBUG HELPERS                         *
117  *********************************************************************/
118 #ifdef CONFIG_CPU_FREQ_DEBUG
119
120 /* what part(s) of the CPUfreq subsystem are debugged? */
121 static unsigned int debug;
122
123 /* is the debug output ratelimit'ed using printk_ratelimit? User can
124  * set or modify this value.
125  */
126 static unsigned int debug_ratelimit = 1;
127
128 /* is the printk_ratelimit'ing enabled? It's enabled after a successful
129  * loading of a cpufreq driver, temporarily disabled when a new policy
130  * is set, and disabled upon cpufreq driver removal
131  */
132 static unsigned int disable_ratelimit = 1;
133 static DEFINE_SPINLOCK(disable_ratelimit_lock);
134
135 static inline void cpufreq_debug_enable_ratelimit(void)
136 {
137         unsigned long flags;
138
139         spin_lock_irqsave(&disable_ratelimit_lock, flags);
140         if (disable_ratelimit)
141                 disable_ratelimit--;
142         spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
143 }
144
145 static inline void cpufreq_debug_disable_ratelimit(void)
146 {
147         unsigned long flags;
148
149         spin_lock_irqsave(&disable_ratelimit_lock, flags);
150         disable_ratelimit++;
151         spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
152 }
153
154 void cpufreq_debug_printk(unsigned int type, const char *prefix, const char *fmt, ...)
155 {
156         char s[256];
157         va_list args;
158         unsigned int len;
159         unsigned long flags;
160         
161         WARN_ON(!prefix);
162         if (type & debug) {
163                 spin_lock_irqsave(&disable_ratelimit_lock, flags);
164                 if (!disable_ratelimit && debug_ratelimit && !printk_ratelimit()) {
165                         spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
166                         return;
167                 }
168                 spin_unlock_irqrestore(&disable_ratelimit_lock, flags);
169
170                 len = snprintf(s, 256, KERN_DEBUG "%s: ", prefix);
171
172                 va_start(args, fmt);
173                 len += vsnprintf(&s[len], (256 - len), fmt, args);
174                 va_end(args);
175
176                 printk(s);
177
178                 WARN_ON(len < 5);
179         }
180 }
181 EXPORT_SYMBOL(cpufreq_debug_printk);
182
183
184 module_param(debug, uint, 0644);
185 MODULE_PARM_DESC(debug, "CPUfreq debugging: add 1 to debug core, 2 to debug drivers, and 4 to debug governors.");
186
187 module_param(debug_ratelimit, uint, 0644);
188 MODULE_PARM_DESC(debug_ratelimit, "CPUfreq debugging: set to 0 to disable ratelimiting.");
189
190 #else /* !CONFIG_CPU_FREQ_DEBUG */
191
192 static inline void cpufreq_debug_enable_ratelimit(void) { return; }
193 static inline void cpufreq_debug_disable_ratelimit(void) { return; }
194
195 #endif /* CONFIG_CPU_FREQ_DEBUG */
196
197
198 /*********************************************************************
199  *            EXTERNALLY AFFECTING FREQUENCY CHANGES                 *
200  *********************************************************************/
201
202 /**
203  * adjust_jiffies - adjust the system "loops_per_jiffy"
204  *
205  * This function alters the system "loops_per_jiffy" for the clock
206  * speed change. Note that loops_per_jiffy cannot be updated on SMP
207  * systems as each CPU might be scaled differently. So, use the arch 
208  * per-CPU loops_per_jiffy value wherever possible.
209  */
210 #ifndef CONFIG_SMP
211 static unsigned long l_p_j_ref;
212 static unsigned int  l_p_j_ref_freq;
213
214 static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci)
215 {
216         if (ci->flags & CPUFREQ_CONST_LOOPS)
217                 return;
218
219         if (!l_p_j_ref_freq) {
220                 l_p_j_ref = loops_per_jiffy;
221                 l_p_j_ref_freq = ci->old;
222                 dprintk("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", l_p_j_ref, l_p_j_ref_freq);
223         }
224         if ((val == CPUFREQ_PRECHANGE  && ci->old < ci->new) ||
225             (val == CPUFREQ_POSTCHANGE && ci->old > ci->new) ||
226             (val == CPUFREQ_RESUMECHANGE || val == CPUFREQ_SUSPENDCHANGE)) {
227                 loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, ci->new);
228                 dprintk("scaling loops_per_jiffy to %lu for frequency %u kHz\n", loops_per_jiffy, ci->new);
229         }
230 }
231 #else
232 static inline void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) { return; }
233 #endif
234
235
236 /**
237  * cpufreq_notify_transition - call notifier chain and adjust_jiffies on frequency transition
238  *
239  * This function calls the transition notifiers and the "adjust_jiffies" function. It is called
240  * twice on all CPU frequency changes that have external effects. 
241  */
242 void cpufreq_notify_transition(struct cpufreq_freqs *freqs, unsigned int state)
243 {
244         BUG_ON(irqs_disabled());
245
246         freqs->flags = cpufreq_driver->flags;
247         dprintk("notification %u of frequency transition to %u kHz\n", state, freqs->new);
248
249         down_read(&cpufreq_notifier_rwsem);
250         switch (state) {
251         case CPUFREQ_PRECHANGE:
252                 /* detect if the driver reported a value as "old frequency" which
253                  * is not equal to what the cpufreq core thinks is "old frequency".
254                  */
255                 if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
256                         if ((likely(cpufreq_cpu_data[freqs->cpu])) &&
257                             (likely(cpufreq_cpu_data[freqs->cpu]->cpu == freqs->cpu)) &&
258                             (likely(cpufreq_cpu_data[freqs->cpu]->cur)) &&
259                             (unlikely(freqs->old != cpufreq_cpu_data[freqs->cpu]->cur)))
260                         {
261                                 dprintk(KERN_WARNING "Warning: CPU frequency is %u, "
262                                        "cpufreq assumed %u kHz.\n", freqs->old, cpufreq_cpu_data[freqs->cpu]->cur);
263                                 freqs->old = cpufreq_cpu_data[freqs->cpu]->cur;
264                         }
265                 }
266                 notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_PRECHANGE, freqs);
267                 adjust_jiffies(CPUFREQ_PRECHANGE, freqs);
268                 break;
269         case CPUFREQ_POSTCHANGE:
270                 adjust_jiffies(CPUFREQ_POSTCHANGE, freqs);
271                 notifier_call_chain(&cpufreq_transition_notifier_list, CPUFREQ_POSTCHANGE, freqs);
272                 if ((likely(cpufreq_cpu_data[freqs->cpu])) && 
273                     (likely(cpufreq_cpu_data[freqs->cpu]->cpu == freqs->cpu)))
274                         cpufreq_cpu_data[freqs->cpu]->cur = freqs->new;
275                 break;
276         }
277         up_read(&cpufreq_notifier_rwsem);
278 }
279 EXPORT_SYMBOL_GPL(cpufreq_notify_transition);
280
281
282
283 /*********************************************************************
284  *                          SYSFS INTERFACE                          *
285  *********************************************************************/
286
287 /**
288  * cpufreq_parse_governor - parse a governor string
289  */
290 static int cpufreq_parse_governor (char *str_governor, unsigned int *policy,
291                                 struct cpufreq_governor **governor)
292 {
293         if (!cpufreq_driver)
294                 return -EINVAL;
295         if (cpufreq_driver->setpolicy) {
296                 if (!strnicmp(str_governor, "performance", CPUFREQ_NAME_LEN)) {
297                         *policy = CPUFREQ_POLICY_PERFORMANCE;
298                         return 0;
299                 } else if (!strnicmp(str_governor, "powersave", CPUFREQ_NAME_LEN)) {
300                         *policy = CPUFREQ_POLICY_POWERSAVE;
301                         return 0;
302                 }
303                 return -EINVAL;
304         } else {
305                 struct cpufreq_governor *t;
306                 down(&cpufreq_governor_sem);
307                 if (!cpufreq_driver || !cpufreq_driver->target)
308                         goto out;
309                 list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
310                         if (!strnicmp(str_governor,t->name,CPUFREQ_NAME_LEN)) {
311                                 *governor = t;
312                                 up(&cpufreq_governor_sem);
313                                 return 0;
314                         }
315                 }
316         out:
317                 up(&cpufreq_governor_sem);
318         }
319         return -EINVAL;
320 }
321 EXPORT_SYMBOL_GPL(cpufreq_parse_governor);
322
323
324 /* drivers/base/cpu.c */
325 extern struct sysdev_class cpu_sysdev_class;
326
327
328 /**
329  * cpufreq_per_cpu_attr_read() / show_##file_name() - print out cpufreq information
330  *
331  * Write out information from cpufreq_driver->policy[cpu]; object must be
332  * "unsigned int".
333  */
334
335 #define show_one(file_name, object)                                     \
336 static ssize_t show_##file_name                                         \
337 (struct cpufreq_policy * policy, char *buf)                             \
338 {                                                                       \
339         return sprintf (buf, "%u\n", policy->object);                   \
340 }
341
342 show_one(cpuinfo_min_freq, cpuinfo.min_freq);
343 show_one(cpuinfo_max_freq, cpuinfo.max_freq);
344 show_one(scaling_min_freq, min);
345 show_one(scaling_max_freq, max);
346 show_one(scaling_cur_freq, cur);
347
348 /**
349  * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access
350  */
351 #define store_one(file_name, object)                    \
352 static ssize_t store_##file_name                                        \
353 (struct cpufreq_policy * policy, const char *buf, size_t count)         \
354 {                                                                       \
355         unsigned int ret = -EINVAL;                                     \
356         struct cpufreq_policy new_policy;                               \
357                                                                         \
358         ret = cpufreq_get_policy(&new_policy, policy->cpu);             \
359         if (ret)                                                        \
360                 return -EINVAL;                                         \
361                                                                         \
362         ret = sscanf (buf, "%u", &new_policy.object);                   \
363         if (ret != 1)                                                   \
364                 return -EINVAL;                                         \
365                                                                         \
366         ret = cpufreq_set_policy(&new_policy);                          \
367                                                                         \
368         return ret ? ret : count;                                       \
369 }
370
371 store_one(scaling_min_freq,min);
372 store_one(scaling_max_freq,max);
373
374 /**
375  * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware
376  */
377 static ssize_t show_cpuinfo_cur_freq (struct cpufreq_policy * policy, char *buf)
378 {
379         unsigned int cur_freq = cpufreq_get(policy->cpu);
380         if (!cur_freq)
381                 return sprintf(buf, "<unknown>");
382         return sprintf(buf, "%u\n", cur_freq);
383 }
384
385
386 /**
387  * show_scaling_governor - show the current policy for the specified CPU
388  */
389 static ssize_t show_scaling_governor (struct cpufreq_policy * policy, char *buf)
390 {
391         if(policy->policy == CPUFREQ_POLICY_POWERSAVE)
392                 return sprintf(buf, "powersave\n");
393         else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE)
394                 return sprintf(buf, "performance\n");
395         else if (policy->governor)
396                 return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", policy->governor->name);
397         return -EINVAL;
398 }
399
400
401 /**
402  * store_scaling_governor - store policy for the specified CPU
403  */
404 static ssize_t store_scaling_governor (struct cpufreq_policy * policy, 
405                                        const char *buf, size_t count) 
406 {
407         unsigned int ret = -EINVAL;
408         char    str_governor[16];
409         struct cpufreq_policy new_policy;
410
411         ret = cpufreq_get_policy(&new_policy, policy->cpu);
412         if (ret)
413                 return ret;
414
415         ret = sscanf (buf, "%15s", str_governor);
416         if (ret != 1)
417                 return -EINVAL;
418
419         if (cpufreq_parse_governor(str_governor, &new_policy.policy, &new_policy.governor))
420                 return -EINVAL;
421
422         ret = cpufreq_set_policy(&new_policy);
423
424         return ret ? ret : count;
425 }
426
427 /**
428  * show_scaling_driver - show the cpufreq driver currently loaded
429  */
430 static ssize_t show_scaling_driver (struct cpufreq_policy * policy, char *buf)
431 {
432         return scnprintf(buf, CPUFREQ_NAME_LEN, "%s\n", cpufreq_driver->name);
433 }
434
435 /**
436  * show_scaling_available_governors - show the available CPUfreq governors
437  */
438 static ssize_t show_scaling_available_governors (struct cpufreq_policy * policy,
439                                 char *buf)
440 {
441         ssize_t i = 0;
442         struct cpufreq_governor *t;
443
444         if (!cpufreq_driver->target) {
445                 i += sprintf(buf, "performance powersave");
446                 goto out;
447         }
448
449         list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
450                 if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) - (CPUFREQ_NAME_LEN + 2)))
451                         goto out;
452                 i += scnprintf(&buf[i], CPUFREQ_NAME_LEN, "%s ", t->name);
453         }
454  out:
455         i += sprintf(&buf[i], "\n");
456         return i;
457 }
458 /**
459  * show_affected_cpus - show the CPUs affected by each transition
460  */
461 static ssize_t show_affected_cpus (struct cpufreq_policy * policy, char *buf)
462 {
463         ssize_t i = 0;
464         unsigned int cpu;
465
466         for_each_cpu_mask(cpu, policy->cpus) {
467                 if (i)
468                         i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " ");
469                 i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu);
470                 if (i >= (PAGE_SIZE - 5))
471                     break;
472         }
473         i += sprintf(&buf[i], "\n");
474         return i;
475 }
476
477
478 #define define_one_ro(_name) \
479 static struct freq_attr _name = \
480 __ATTR(_name, 0444, show_##_name, NULL)
481
482 #define define_one_ro0400(_name) \
483 static struct freq_attr _name = \
484 __ATTR(_name, 0400, show_##_name, NULL)
485
486 #define define_one_rw(_name) \
487 static struct freq_attr _name = \
488 __ATTR(_name, 0644, show_##_name, store_##_name)
489
490 define_one_ro0400(cpuinfo_cur_freq);
491 define_one_ro(cpuinfo_min_freq);
492 define_one_ro(cpuinfo_max_freq);
493 define_one_ro(scaling_available_governors);
494 define_one_ro(scaling_driver);
495 define_one_ro(scaling_cur_freq);
496 define_one_ro(affected_cpus);
497 define_one_rw(scaling_min_freq);
498 define_one_rw(scaling_max_freq);
499 define_one_rw(scaling_governor);
500
501 static struct attribute * default_attrs[] = {
502         &cpuinfo_min_freq.attr,
503         &cpuinfo_max_freq.attr,
504         &scaling_min_freq.attr,
505         &scaling_max_freq.attr,
506         &affected_cpus.attr,
507         &scaling_governor.attr,
508         &scaling_driver.attr,
509         &scaling_available_governors.attr,
510         NULL
511 };
512
513 #define to_policy(k) container_of(k,struct cpufreq_policy,kobj)
514 #define to_attr(a) container_of(a,struct freq_attr,attr)
515
516 static ssize_t show(struct kobject * kobj, struct attribute * attr ,char * buf)
517 {
518         struct cpufreq_policy * policy = to_policy(kobj);
519         struct freq_attr * fattr = to_attr(attr);
520         ssize_t ret;
521         policy = cpufreq_cpu_get(policy->cpu);
522         if (!policy)
523                 return -EINVAL;
524         ret = fattr->show ? fattr->show(policy,buf) : -EIO;
525         cpufreq_cpu_put(policy);
526         return ret;
527 }
528
529 static ssize_t store(struct kobject * kobj, struct attribute * attr, 
530                      const char * buf, size_t count)
531 {
532         struct cpufreq_policy * policy = to_policy(kobj);
533         struct freq_attr * fattr = to_attr(attr);
534         ssize_t ret;
535         policy = cpufreq_cpu_get(policy->cpu);
536         if (!policy)
537                 return -EINVAL;
538         ret = fattr->store ? fattr->store(policy,buf,count) : -EIO;
539         cpufreq_cpu_put(policy);
540         return ret;
541 }
542
543 static void cpufreq_sysfs_release(struct kobject * kobj)
544 {
545         struct cpufreq_policy * policy = to_policy(kobj);
546         dprintk("last reference is dropped\n");
547         complete(&policy->kobj_unregister);
548 }
549
550 static struct sysfs_ops sysfs_ops = {
551         .show   = show,
552         .store  = store,
553 };
554
555 static struct kobj_type ktype_cpufreq = {
556         .sysfs_ops      = &sysfs_ops,
557         .default_attrs  = default_attrs,
558         .release        = cpufreq_sysfs_release,
559 };
560
561
562 /**
563  * cpufreq_add_dev - add a CPU device
564  *
565  * Adds the cpufreq interface for a CPU device. 
566  */
567 static int cpufreq_add_dev (struct sys_device * sys_dev)
568 {
569         unsigned int cpu = sys_dev->id;
570         int ret = 0;
571         struct cpufreq_policy new_policy;
572         struct cpufreq_policy *policy;
573         struct freq_attr **drv_attr;
574         unsigned long flags;
575         unsigned int j;
576
577         cpufreq_debug_disable_ratelimit();
578         dprintk("adding CPU %u\n", cpu);
579
580 #ifdef CONFIG_SMP
581         /* check whether a different CPU already registered this
582          * CPU because it is in the same boat. */
583         policy = cpufreq_cpu_get(cpu);
584         if (unlikely(policy)) {
585                 cpu_sys_devices[cpu] = sys_dev;
586                 dprintk("CPU already managed, adding link\n");
587                 sysfs_create_link(&sys_dev->kobj, &policy->kobj, "cpufreq");
588                 cpufreq_debug_enable_ratelimit();
589                 return 0;
590         }
591 #endif
592
593         if (!try_module_get(cpufreq_driver->owner)) {
594                 ret = -EINVAL;
595                 goto module_out;
596         }
597
598         policy = kmalloc(sizeof(struct cpufreq_policy), GFP_KERNEL);
599         if (!policy) {
600                 ret = -ENOMEM;
601                 goto nomem_out;
602         }
603         memset(policy, 0, sizeof(struct cpufreq_policy));
604
605         policy->cpu = cpu;
606         policy->cpus = cpumask_of_cpu(cpu);
607
608         init_MUTEX_LOCKED(&policy->lock);
609         init_completion(&policy->kobj_unregister);
610         INIT_WORK(&policy->update, handle_update, (void *)(long)cpu);
611
612         /* call driver. From then on the cpufreq must be able
613          * to accept all calls to ->verify and ->setpolicy for this CPU
614          */
615         ret = cpufreq_driver->init(policy);
616         if (ret) {
617                 dprintk("initialization failed\n");
618                 goto err_out;
619         }
620
621         memcpy(&new_policy, policy, sizeof(struct cpufreq_policy));
622
623         /* prepare interface data */
624         policy->kobj.parent = &sys_dev->kobj;
625         policy->kobj.ktype = &ktype_cpufreq;
626         strlcpy(policy->kobj.name, "cpufreq", KOBJ_NAME_LEN);
627
628         ret = kobject_register(&policy->kobj);
629         if (ret)
630                 goto err_out_driver_exit;
631
632         /* set up files for this cpu device */
633         drv_attr = cpufreq_driver->attr;
634         while ((drv_attr) && (*drv_attr)) {
635                 sysfs_create_file(&policy->kobj, &((*drv_attr)->attr));
636                 drv_attr++;
637         }
638         if (cpufreq_driver->get)
639                 sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr);
640         if (cpufreq_driver->target)
641                 sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr);
642
643         spin_lock_irqsave(&cpufreq_driver_lock, flags);
644         for_each_cpu_mask(j, policy->cpus)
645                 cpufreq_cpu_data[j] = policy;
646         spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
647         policy->governor = NULL; /* to assure that the starting sequence is
648                                   * run in cpufreq_set_policy */
649         up(&policy->lock);
650         
651         /* set default policy */
652         
653         ret = cpufreq_set_policy(&new_policy);
654         if (ret) {
655                 dprintk("setting policy failed\n");
656                 goto err_out_unregister;
657         }
658
659         module_put(cpufreq_driver->owner);
660         cpu_sys_devices[cpu] = sys_dev;
661         dprintk("initialization complete\n");
662         cpufreq_debug_enable_ratelimit();
663         
664         return 0;
665
666
667 err_out_unregister:
668         spin_lock_irqsave(&cpufreq_driver_lock, flags);
669         for_each_cpu_mask(j, policy->cpus)
670                 cpufreq_cpu_data[j] = NULL;
671         spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
672
673         kobject_unregister(&policy->kobj);
674         wait_for_completion(&policy->kobj_unregister);
675
676 err_out_driver_exit:
677         if (cpufreq_driver->exit)
678                 cpufreq_driver->exit(policy);
679
680 err_out:
681         kfree(policy);
682
683 nomem_out:
684         module_put(cpufreq_driver->owner);
685  module_out:
686         cpufreq_debug_enable_ratelimit();
687         return ret;
688 }
689
690
691 /**
692  * cpufreq_remove_dev - remove a CPU device
693  *
694  * Removes the cpufreq interface for a CPU device.
695  */
696 static int cpufreq_remove_dev (struct sys_device * sys_dev)
697 {
698         unsigned int cpu = sys_dev->id;
699         unsigned long flags;
700         struct cpufreq_policy *data;
701 #ifdef CONFIG_SMP
702         unsigned int j;
703 #endif
704
705         cpufreq_debug_disable_ratelimit();
706         dprintk("unregistering CPU %u\n", cpu);
707
708         spin_lock_irqsave(&cpufreq_driver_lock, flags);
709         data = cpufreq_cpu_data[cpu];
710
711         if (!data) {
712                 spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
713                 cpu_sys_devices[cpu] = NULL;
714                 cpufreq_debug_enable_ratelimit();
715                 return -EINVAL;
716         }
717         cpufreq_cpu_data[cpu] = NULL;
718
719
720 #ifdef CONFIG_SMP
721         /* if this isn't the CPU which is the parent of the kobj, we
722          * only need to unlink, put and exit 
723          */
724         if (unlikely(cpu != data->cpu)) {
725                 dprintk("removing link\n");
726                 spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
727                 sysfs_remove_link(&sys_dev->kobj, "cpufreq");
728                 cpu_sys_devices[cpu] = NULL;
729                 cpufreq_cpu_put(data);
730                 cpufreq_debug_enable_ratelimit();
731                 return 0;
732         }
733 #endif
734
735         cpu_sys_devices[cpu] = NULL;
736
737         if (!kobject_get(&data->kobj)) {
738                 spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
739                 cpufreq_debug_enable_ratelimit();
740                 return -EFAULT;
741         }
742
743 #ifdef CONFIG_SMP
744         /* if we have other CPUs still registered, we need to unlink them,
745          * or else wait_for_completion below will lock up. Clean the
746          * cpufreq_cpu_data[] while holding the lock, and remove the sysfs
747          * links afterwards.
748          */
749         if (unlikely(cpus_weight(data->cpus) > 1)) {
750                 for_each_cpu_mask(j, data->cpus) {
751                         if (j == cpu)
752                                 continue;
753                         cpufreq_cpu_data[j] = NULL;
754                 }
755         }
756
757         spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
758
759         if (unlikely(cpus_weight(data->cpus) > 1)) {
760                 for_each_cpu_mask(j, data->cpus) {
761                         if (j == cpu)
762                                 continue;
763                         dprintk("removing link for cpu %u\n", j);
764                         sysfs_remove_link(&cpu_sys_devices[j]->kobj, "cpufreq");
765                         cpufreq_cpu_put(data);
766                 }
767         }
768 #else
769         spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
770 #endif
771
772         down(&data->lock);
773         if (cpufreq_driver->target)
774                 __cpufreq_governor(data, CPUFREQ_GOV_STOP);
775         cpufreq_driver->target = NULL;
776         up(&data->lock);
777
778         kobject_unregister(&data->kobj);
779
780         kobject_put(&data->kobj);
781
782         /* we need to make sure that the underlying kobj is actually
783          * not referenced anymore by anybody before we proceed with 
784          * unloading.
785          */
786         dprintk("waiting for dropping of refcount\n");
787         wait_for_completion(&data->kobj_unregister);
788         dprintk("wait complete\n");
789
790         if (cpufreq_driver->exit)
791                 cpufreq_driver->exit(data);
792
793         kfree(data);
794
795         cpufreq_debug_enable_ratelimit();
796
797         return 0;
798 }
799
800
801 static void handle_update(void *data)
802 {
803         unsigned int cpu = (unsigned int)(long)data;
804         dprintk("handle_update for cpu %u called\n", cpu);
805         cpufreq_update_policy(cpu);
806 }
807
808 /**
809  *      cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're in deep trouble.
810  *      @cpu: cpu number
811  *      @old_freq: CPU frequency the kernel thinks the CPU runs at
812  *      @new_freq: CPU frequency the CPU actually runs at
813  *
814  *      We adjust to current frequency first, and need to clean up later. So either call
815  *      to cpufreq_update_policy() or schedule handle_update()).
816  */
817 static void cpufreq_out_of_sync(unsigned int cpu, unsigned int old_freq, unsigned int new_freq)
818 {
819         struct cpufreq_freqs freqs;
820
821         dprintk(KERN_WARNING "Warning: CPU frequency out of sync: cpufreq and timing "
822                "core thinks of %u, is %u kHz.\n", old_freq, new_freq);
823
824         freqs.cpu = cpu;
825         freqs.old = old_freq;
826         freqs.new = new_freq;
827         cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
828         cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
829 }
830
831
832 /** 
833  * cpufreq_get - get the current CPU frequency (in kHz)
834  * @cpu: CPU number
835  *
836  * Get the CPU current (static) CPU frequency
837  */
838 unsigned int cpufreq_get(unsigned int cpu)
839 {
840         struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
841         unsigned int ret = 0;
842
843         if (!policy)
844                 return 0;
845
846         if (!cpufreq_driver->get)
847                 goto out;
848
849         down(&policy->lock);
850
851         ret = cpufreq_driver->get(cpu);
852
853         if (ret && policy->cur && !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) 
854         {
855                 /* verify no discrepancy between actual and saved value exists */
856                 if (unlikely(ret != policy->cur)) {
857                         cpufreq_out_of_sync(cpu, policy->cur, ret);
858                         schedule_work(&policy->update);
859                 }
860         }
861
862         up(&policy->lock);
863
864  out:
865         cpufreq_cpu_put(policy);
866
867         return (ret);
868 }
869 EXPORT_SYMBOL(cpufreq_get);
870
871
872 /**
873  *      cpufreq_suspend - let the low level driver prepare for suspend
874  */
875
876 static int cpufreq_suspend(struct sys_device * sysdev, pm_message_t pmsg)
877 {
878         int cpu = sysdev->id;
879         unsigned int ret = 0;
880         unsigned int cur_freq = 0;
881         struct cpufreq_policy *cpu_policy;
882
883         dprintk("resuming cpu %u\n", cpu);
884
885         if (!cpu_online(cpu))
886                 return 0;
887
888         /* we may be lax here as interrupts are off. Nonetheless
889          * we need to grab the correct cpu policy, as to check
890          * whether we really run on this CPU.
891          */
892
893         cpu_policy = cpufreq_cpu_get(cpu);
894         if (!cpu_policy)
895                 return -EINVAL;
896
897         /* only handle each CPU group once */
898         if (unlikely(cpu_policy->cpu != cpu)) {
899                 cpufreq_cpu_put(cpu_policy);
900                 return 0;
901         }
902
903         if (cpufreq_driver->suspend) {
904                 ret = cpufreq_driver->suspend(cpu_policy, pmsg);
905                 if (ret) {
906                         printk(KERN_ERR "cpufreq: suspend failed in ->suspend "
907                                         "step on CPU %u\n", cpu_policy->cpu);
908                         cpufreq_cpu_put(cpu_policy);
909                         return ret;
910                 }
911         }
912
913
914         if (cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)
915                 goto out;
916
917         if (cpufreq_driver->get)
918                 cur_freq = cpufreq_driver->get(cpu_policy->cpu);
919
920         if (!cur_freq || !cpu_policy->cur) {
921                 printk(KERN_ERR "cpufreq: suspend failed to assert current "
922                        "frequency is what timing core thinks it is.\n");
923                 goto out;
924         }
925
926         if (unlikely(cur_freq != cpu_policy->cur)) {
927                 struct cpufreq_freqs freqs;
928
929                 if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN))
930                         dprintk(KERN_DEBUG "Warning: CPU frequency is %u, "
931                                "cpufreq assumed %u kHz.\n",
932                                cur_freq, cpu_policy->cur);
933
934                 freqs.cpu = cpu;
935                 freqs.old = cpu_policy->cur;
936                 freqs.new = cur_freq;
937
938                 notifier_call_chain(&cpufreq_transition_notifier_list,
939                                     CPUFREQ_SUSPENDCHANGE, &freqs);
940                 adjust_jiffies(CPUFREQ_SUSPENDCHANGE, &freqs);
941
942                 cpu_policy->cur = cur_freq;
943         }
944
945  out:
946         cpufreq_cpu_put(cpu_policy);
947         return 0;
948 }
949
950 /**
951  *      cpufreq_resume -  restore proper CPU frequency handling after resume
952  *
953  *      1.) resume CPUfreq hardware support (cpufreq_driver->resume())
954  *      2.) if ->target and !CPUFREQ_CONST_LOOPS: verify we're in sync
955  *      3.) schedule call cpufreq_update_policy() ASAP as interrupts are
956  *          restored.
957  */
958 static int cpufreq_resume(struct sys_device * sysdev)
959 {
960         int cpu = sysdev->id;
961         unsigned int ret = 0;
962         struct cpufreq_policy *cpu_policy;
963
964         dprintk("resuming cpu %u\n", cpu);
965
966         if (!cpu_online(cpu))
967                 return 0;
968
969         /* we may be lax here as interrupts are off. Nonetheless
970          * we need to grab the correct cpu policy, as to check
971          * whether we really run on this CPU.
972          */
973
974         cpu_policy = cpufreq_cpu_get(cpu);
975         if (!cpu_policy)
976                 return -EINVAL;
977
978         /* only handle each CPU group once */
979         if (unlikely(cpu_policy->cpu != cpu)) {
980                 cpufreq_cpu_put(cpu_policy);
981                 return 0;
982         }
983
984         if (cpufreq_driver->resume) {
985                 ret = cpufreq_driver->resume(cpu_policy);
986                 if (ret) {
987                         printk(KERN_ERR "cpufreq: resume failed in ->resume "
988                                         "step on CPU %u\n", cpu_policy->cpu);
989                         cpufreq_cpu_put(cpu_policy);
990                         return ret;
991                 }
992         }
993
994         if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) {
995                 unsigned int cur_freq = 0;
996
997                 if (cpufreq_driver->get)
998                         cur_freq = cpufreq_driver->get(cpu_policy->cpu);
999
1000                 if (!cur_freq || !cpu_policy->cur) {
1001                         printk(KERN_ERR "cpufreq: resume failed to assert "
1002                                         "current frequency is what timing core "
1003                                         "thinks it is.\n");
1004                         goto out;
1005                 }
1006
1007                 if (unlikely(cur_freq != cpu_policy->cur)) {
1008                         struct cpufreq_freqs freqs;
1009
1010                         if (!(cpufreq_driver->flags & CPUFREQ_PM_NO_WARN))
1011                                 dprintk(KERN_WARNING "Warning: CPU frequency"
1012                                        "is %u, cpufreq assumed %u kHz.\n",
1013                                        cur_freq, cpu_policy->cur);
1014
1015                         freqs.cpu = cpu;
1016                         freqs.old = cpu_policy->cur;
1017                         freqs.new = cur_freq;
1018
1019                         notifier_call_chain(&cpufreq_transition_notifier_list,
1020                                         CPUFREQ_RESUMECHANGE, &freqs);
1021                         adjust_jiffies(CPUFREQ_RESUMECHANGE, &freqs);
1022
1023                         cpu_policy->cur = cur_freq;
1024                 }
1025         }
1026
1027 out:
1028         schedule_work(&cpu_policy->update);
1029         cpufreq_cpu_put(cpu_policy);
1030         return ret;
1031 }
1032
1033 static struct sysdev_driver cpufreq_sysdev_driver = {
1034         .add            = cpufreq_add_dev,
1035         .remove         = cpufreq_remove_dev,
1036         .suspend        = cpufreq_suspend,
1037         .resume         = cpufreq_resume,
1038 };
1039
1040
1041 /*********************************************************************
1042  *                     NOTIFIER LISTS INTERFACE                      *
1043  *********************************************************************/
1044
1045 /**
1046  *      cpufreq_register_notifier - register a driver with cpufreq
1047  *      @nb: notifier function to register
1048  *      @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1049  *
1050  *      Add a driver to one of two lists: either a list of drivers that 
1051  *      are notified about clock rate changes (once before and once after
1052  *      the transition), or a list of drivers that are notified about
1053  *      changes in cpufreq policy.
1054  *
1055  *      This function may sleep, and has the same return conditions as
1056  *      notifier_chain_register.
1057  */
1058 int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list)
1059 {
1060         int ret;
1061
1062         down_write(&cpufreq_notifier_rwsem);
1063         switch (list) {
1064         case CPUFREQ_TRANSITION_NOTIFIER:
1065                 ret = notifier_chain_register(&cpufreq_transition_notifier_list, nb);
1066                 break;
1067         case CPUFREQ_POLICY_NOTIFIER:
1068                 ret = notifier_chain_register(&cpufreq_policy_notifier_list, nb);
1069                 break;
1070         default:
1071                 ret = -EINVAL;
1072         }
1073         up_write(&cpufreq_notifier_rwsem);
1074
1075         return ret;
1076 }
1077 EXPORT_SYMBOL(cpufreq_register_notifier);
1078
1079
1080 /**
1081  *      cpufreq_unregister_notifier - unregister a driver with cpufreq
1082  *      @nb: notifier block to be unregistered
1083  *      @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER
1084  *
1085  *      Remove a driver from the CPU frequency notifier list.
1086  *
1087  *      This function may sleep, and has the same return conditions as
1088  *      notifier_chain_unregister.
1089  */
1090 int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list)
1091 {
1092         int ret;
1093
1094         down_write(&cpufreq_notifier_rwsem);
1095         switch (list) {
1096         case CPUFREQ_TRANSITION_NOTIFIER:
1097                 ret = notifier_chain_unregister(&cpufreq_transition_notifier_list, nb);
1098                 break;
1099         case CPUFREQ_POLICY_NOTIFIER:
1100                 ret = notifier_chain_unregister(&cpufreq_policy_notifier_list, nb);
1101                 break;
1102         default:
1103                 ret = -EINVAL;
1104         }
1105         up_write(&cpufreq_notifier_rwsem);
1106
1107         return ret;
1108 }
1109 EXPORT_SYMBOL(cpufreq_unregister_notifier);
1110
1111
1112 /*********************************************************************
1113  *                              GOVERNORS                            *
1114  *********************************************************************/
1115
1116
1117 int __cpufreq_driver_target(struct cpufreq_policy *policy,
1118                             unsigned int target_freq,
1119                             unsigned int relation)
1120 {
1121         int retval = -EINVAL;
1122         lock_cpu_hotplug();
1123         dprintk("target for CPU %u: %u kHz, relation %u\n", policy->cpu,
1124                 target_freq, relation);
1125         if (cpu_online(policy->cpu) && cpufreq_driver->target)
1126                 retval = cpufreq_driver->target(policy, target_freq, relation);
1127         unlock_cpu_hotplug();
1128         return retval;
1129 }
1130 EXPORT_SYMBOL_GPL(__cpufreq_driver_target);
1131
1132
1133 int cpufreq_driver_target(struct cpufreq_policy *policy,
1134                           unsigned int target_freq,
1135                           unsigned int relation)
1136 {
1137         int ret;
1138
1139         policy = cpufreq_cpu_get(policy->cpu);
1140         if (!policy)
1141                 return -EINVAL;
1142
1143         down(&policy->lock);
1144
1145         ret = __cpufreq_driver_target(policy, target_freq, relation);
1146
1147         up(&policy->lock);
1148
1149         cpufreq_cpu_put(policy);
1150
1151         return ret;
1152 }
1153 EXPORT_SYMBOL_GPL(cpufreq_driver_target);
1154
1155
1156 static int __cpufreq_governor(struct cpufreq_policy *policy, unsigned int event)
1157 {
1158         int ret;
1159
1160         if (!try_module_get(policy->governor->owner))
1161                 return -EINVAL;
1162
1163         dprintk("__cpufreq_governor for CPU %u, event %u\n", policy->cpu, event);
1164         ret = policy->governor->governor(policy, event);
1165
1166         /* we keep one module reference alive for each CPU governed by this CPU */
1167         if ((event != CPUFREQ_GOV_START) || ret)
1168                 module_put(policy->governor->owner);
1169         if ((event == CPUFREQ_GOV_STOP) && !ret)
1170                 module_put(policy->governor->owner);
1171
1172         return ret;
1173 }
1174
1175
1176 int cpufreq_governor(unsigned int cpu, unsigned int event)
1177 {
1178         int ret = 0;
1179         struct cpufreq_policy *policy = cpufreq_cpu_get(cpu);
1180
1181         if (!policy)
1182                 return -EINVAL;
1183
1184         down(&policy->lock);
1185         ret = __cpufreq_governor(policy, event);
1186         up(&policy->lock);
1187
1188         cpufreq_cpu_put(policy);
1189
1190         return ret;
1191 }
1192 EXPORT_SYMBOL_GPL(cpufreq_governor);
1193
1194
1195 int cpufreq_register_governor(struct cpufreq_governor *governor)
1196 {
1197         struct cpufreq_governor *t;
1198
1199         if (!governor)
1200                 return -EINVAL;
1201
1202         down(&cpufreq_governor_sem);
1203         
1204         list_for_each_entry(t, &cpufreq_governor_list, governor_list) {
1205                 if (!strnicmp(governor->name,t->name,CPUFREQ_NAME_LEN)) {
1206                         up(&cpufreq_governor_sem);
1207                         return -EBUSY;
1208                 }
1209         }
1210         list_add(&governor->governor_list, &cpufreq_governor_list);
1211
1212         up(&cpufreq_governor_sem);
1213
1214         return 0;
1215 }
1216 EXPORT_SYMBOL_GPL(cpufreq_register_governor);
1217
1218
1219 void cpufreq_unregister_governor(struct cpufreq_governor *governor)
1220 {
1221         if (!governor)
1222                 return;
1223
1224         down(&cpufreq_governor_sem);
1225         list_del(&governor->governor_list);
1226         up(&cpufreq_governor_sem);
1227         return;
1228 }
1229 EXPORT_SYMBOL_GPL(cpufreq_unregister_governor);
1230
1231
1232
1233 /*********************************************************************
1234  *                          POLICY INTERFACE                         *
1235  *********************************************************************/
1236
1237 /**
1238  * cpufreq_get_policy - get the current cpufreq_policy
1239  * @policy: struct cpufreq_policy into which the current cpufreq_policy is written
1240  *
1241  * Reads the current cpufreq policy.
1242  */
1243 int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu)
1244 {
1245         struct cpufreq_policy *cpu_policy;
1246         if (!policy)
1247                 return -EINVAL;
1248
1249         cpu_policy = cpufreq_cpu_get(cpu);
1250         if (!cpu_policy)
1251                 return -EINVAL;
1252
1253         down(&cpu_policy->lock);
1254         memcpy(policy, cpu_policy, sizeof(struct cpufreq_policy));
1255         up(&cpu_policy->lock);
1256
1257         cpufreq_cpu_put(cpu_policy);
1258
1259         return 0;
1260 }
1261 EXPORT_SYMBOL(cpufreq_get_policy);
1262
1263
1264 static int __cpufreq_set_policy(struct cpufreq_policy *data, struct cpufreq_policy *policy)
1265 {
1266         int ret = 0;
1267
1268         cpufreq_debug_disable_ratelimit();
1269         dprintk("setting new policy for CPU %u: %u - %u kHz\n", policy->cpu,
1270                 policy->min, policy->max);
1271
1272         memcpy(&policy->cpuinfo, 
1273                &data->cpuinfo, 
1274                sizeof(struct cpufreq_cpuinfo));
1275
1276         /* verify the cpu speed can be set within this limit */
1277         ret = cpufreq_driver->verify(policy);
1278         if (ret)
1279                 goto error_out;
1280
1281         down_read(&cpufreq_notifier_rwsem);
1282
1283         /* adjust if necessary - all reasons */
1284         notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_ADJUST,
1285                             policy);
1286
1287         /* adjust if necessary - hardware incompatibility*/
1288         notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_INCOMPATIBLE,
1289                             policy);
1290
1291         /* verify the cpu speed can be set within this limit,
1292            which might be different to the first one */
1293         ret = cpufreq_driver->verify(policy);
1294         if (ret) {
1295                 up_read(&cpufreq_notifier_rwsem);
1296                 goto error_out;
1297         }
1298
1299         /* notification of the new policy */
1300         notifier_call_chain(&cpufreq_policy_notifier_list, CPUFREQ_NOTIFY,
1301                             policy);
1302
1303         up_read(&cpufreq_notifier_rwsem);
1304
1305         data->min    = policy->min;
1306         data->max    = policy->max;
1307
1308         dprintk("new min and max freqs are %u - %u kHz\n", data->min, data->max);
1309
1310         if (cpufreq_driver->setpolicy) {
1311                 data->policy = policy->policy;
1312                 dprintk("setting range\n");
1313                 ret = cpufreq_driver->setpolicy(policy);
1314         } else {
1315                 if (policy->governor != data->governor) {
1316                         /* save old, working values */
1317                         struct cpufreq_governor *old_gov = data->governor;
1318
1319                         dprintk("governor switch\n");
1320
1321                         /* end old governor */
1322                         if (data->governor)
1323                                 __cpufreq_governor(data, CPUFREQ_GOV_STOP);
1324
1325                         /* start new governor */
1326                         data->governor = policy->governor;
1327                         if (__cpufreq_governor(data, CPUFREQ_GOV_START)) {
1328                                 /* new governor failed, so re-start old one */
1329                                 dprintk("starting governor %s failed\n", data->governor->name);
1330                                 if (old_gov) {
1331                                         data->governor = old_gov;
1332                                         __cpufreq_governor(data, CPUFREQ_GOV_START);
1333                                 }
1334                                 ret = -EINVAL;
1335                                 goto error_out;
1336                         }
1337                         /* might be a policy change, too, so fall through */
1338                 }
1339                 dprintk("governor: change or update limits\n");
1340                 __cpufreq_governor(data, CPUFREQ_GOV_LIMITS);
1341         }
1342
1343  error_out:
1344         cpufreq_debug_enable_ratelimit();
1345         return ret;
1346 }
1347
1348 /**
1349  *      cpufreq_set_policy - set a new CPUFreq policy
1350  *      @policy: policy to be set.
1351  *
1352  *      Sets a new CPU frequency and voltage scaling policy.
1353  */
1354 int cpufreq_set_policy(struct cpufreq_policy *policy)
1355 {
1356         int ret = 0;
1357         struct cpufreq_policy *data;
1358
1359         if (!policy)
1360                 return -EINVAL;
1361
1362         data = cpufreq_cpu_get(policy->cpu);
1363         if (!data)
1364                 return -EINVAL;
1365
1366         /* lock this CPU */
1367         down(&data->lock);
1368
1369         ret = __cpufreq_set_policy(data, policy);
1370         data->user_policy.min = data->min;
1371         data->user_policy.max = data->max;
1372         data->user_policy.policy = data->policy;
1373         data->user_policy.governor = data->governor;
1374
1375         up(&data->lock);
1376         cpufreq_cpu_put(data);
1377
1378         return ret;
1379 }
1380 EXPORT_SYMBOL(cpufreq_set_policy);
1381
1382
1383 /**
1384  *      cpufreq_update_policy - re-evaluate an existing cpufreq policy
1385  *      @cpu: CPU which shall be re-evaluated
1386  *
1387  *      Usefull for policy notifiers which have different necessities
1388  *      at different times.
1389  */
1390 int cpufreq_update_policy(unsigned int cpu)
1391 {
1392         struct cpufreq_policy *data = cpufreq_cpu_get(cpu);
1393         struct cpufreq_policy policy;
1394         int ret = 0;
1395
1396         if (!data)
1397                 return -ENODEV;
1398
1399         down(&data->lock);
1400
1401         dprintk("updating policy for CPU %u\n", cpu);
1402         memcpy(&policy, 
1403                data,
1404                sizeof(struct cpufreq_policy));
1405         policy.min = data->user_policy.min;
1406         policy.max = data->user_policy.max;
1407         policy.policy = data->user_policy.policy;
1408         policy.governor = data->user_policy.governor;
1409
1410         ret = __cpufreq_set_policy(data, &policy);
1411
1412         up(&data->lock);
1413
1414         cpufreq_cpu_put(data);
1415         return ret;
1416 }
1417 EXPORT_SYMBOL(cpufreq_update_policy);
1418
1419
1420 /*********************************************************************
1421  *               REGISTER / UNREGISTER CPUFREQ DRIVER                *
1422  *********************************************************************/
1423
1424 /**
1425  * cpufreq_register_driver - register a CPU Frequency driver
1426  * @driver_data: A struct cpufreq_driver containing the values#
1427  * submitted by the CPU Frequency driver.
1428  *
1429  *   Registers a CPU Frequency driver to this core code. This code 
1430  * returns zero on success, -EBUSY when another driver got here first
1431  * (and isn't unregistered in the meantime). 
1432  *
1433  */
1434 int cpufreq_register_driver(struct cpufreq_driver *driver_data)
1435 {
1436         unsigned long flags;
1437         int ret;
1438
1439         if (!driver_data || !driver_data->verify || !driver_data->init ||
1440             ((!driver_data->setpolicy) && (!driver_data->target)))
1441                 return -EINVAL;
1442
1443         dprintk("trying to register driver %s\n", driver_data->name);
1444
1445         if (driver_data->setpolicy)
1446                 driver_data->flags |= CPUFREQ_CONST_LOOPS;
1447
1448         spin_lock_irqsave(&cpufreq_driver_lock, flags);
1449         if (cpufreq_driver) {
1450                 spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
1451                 return -EBUSY;
1452         }
1453         cpufreq_driver = driver_data;
1454         spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
1455
1456         ret = sysdev_driver_register(&cpu_sysdev_class,&cpufreq_sysdev_driver);
1457
1458         if ((!ret) && !(cpufreq_driver->flags & CPUFREQ_STICKY)) {
1459                 int i;
1460                 ret = -ENODEV;
1461
1462                 /* check for at least one working CPU */
1463                 for (i=0; i<NR_CPUS; i++)
1464                         if (cpufreq_cpu_data[i])
1465                                 ret = 0;
1466
1467                 /* if all ->init() calls failed, unregister */
1468                 if (ret) {
1469                         dprintk("no CPU initialized for driver %s\n", driver_data->name);
1470                         sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver);
1471
1472                         spin_lock_irqsave(&cpufreq_driver_lock, flags);
1473                         cpufreq_driver = NULL;
1474                         spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
1475                 }
1476         }
1477
1478         if (!ret) {
1479                 dprintk("driver %s up and running\n", driver_data->name);
1480                 cpufreq_debug_enable_ratelimit();
1481         }
1482
1483         return (ret);
1484 }
1485 EXPORT_SYMBOL_GPL(cpufreq_register_driver);
1486
1487
1488 /**
1489  * cpufreq_unregister_driver - unregister the current CPUFreq driver
1490  *
1491  *    Unregister the current CPUFreq driver. Only call this if you have 
1492  * the right to do so, i.e. if you have succeeded in initialising before!
1493  * Returns zero if successful, and -EINVAL if the cpufreq_driver is
1494  * currently not initialised.
1495  */
1496 int cpufreq_unregister_driver(struct cpufreq_driver *driver)
1497 {
1498         unsigned long flags;
1499
1500         cpufreq_debug_disable_ratelimit();
1501
1502         if (!cpufreq_driver || (driver != cpufreq_driver)) {
1503                 cpufreq_debug_enable_ratelimit();
1504                 return -EINVAL;
1505         }
1506
1507         dprintk("unregistering driver %s\n", driver->name);
1508
1509         sysdev_driver_unregister(&cpu_sysdev_class, &cpufreq_sysdev_driver);
1510
1511         spin_lock_irqsave(&cpufreq_driver_lock, flags);
1512         cpufreq_driver = NULL;
1513         spin_unlock_irqrestore(&cpufreq_driver_lock, flags);
1514
1515         return 0;
1516 }
1517 EXPORT_SYMBOL_GPL(cpufreq_unregister_driver);