[CPUFREQ] move policy's governor initialisation out of low-level drivers into cpufreq...
[linux-3.10.git] / arch / ia64 / kernel / cpufreq / acpi-cpufreq.c
1 /*
2  * arch/ia64/kernel/cpufreq/acpi-cpufreq.c
3  * This file provides the ACPI based P-state support. This
4  * module works with generic cpufreq infrastructure. Most of
5  * the code is based on i386 version
6  * (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c)
7  *
8  * Copyright (C) 2005 Intel Corp
9  *      Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
10  */
11
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/init.h>
15 #include <linux/cpufreq.h>
16 #include <linux/proc_fs.h>
17 #include <linux/seq_file.h>
18 #include <asm/io.h>
19 #include <asm/uaccess.h>
20 #include <asm/pal.h>
21
22 #include <linux/acpi.h>
23 #include <acpi/processor.h>
24
25 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
26
27 MODULE_AUTHOR("Venkatesh Pallipadi");
28 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
29 MODULE_LICENSE("GPL");
30
31
32 struct cpufreq_acpi_io {
33         struct acpi_processor_performance       acpi_data;
34         struct cpufreq_frequency_table          *freq_table;
35         unsigned int                            resume;
36 };
37
38 static struct cpufreq_acpi_io   *acpi_io_data[NR_CPUS];
39
40 static struct cpufreq_driver acpi_cpufreq_driver;
41
42
43 static int
44 processor_set_pstate (
45         u32     value)
46 {
47         s64 retval;
48
49         dprintk("processor_set_pstate\n");
50
51         retval = ia64_pal_set_pstate((u64)value);
52
53         if (retval) {
54                 dprintk("Failed to set freq to 0x%x, with error 0x%x\n",
55                         value, retval);
56                 return -ENODEV;
57         }
58         return (int)retval;
59 }
60
61
62 static int
63 processor_get_pstate (
64         u32     *value)
65 {
66         u64     pstate_index = 0;
67         s64     retval;
68
69         dprintk("processor_get_pstate\n");
70
71         retval = ia64_pal_get_pstate(&pstate_index,
72                                      PAL_GET_PSTATE_TYPE_INSTANT);
73         *value = (u32) pstate_index;
74
75         if (retval)
76                 dprintk("Failed to get current freq with "
77                         "error 0x%x, idx 0x%x\n", retval, *value);
78
79         return (int)retval;
80 }
81
82
83 /* To be used only after data->acpi_data is initialized */
84 static unsigned
85 extract_clock (
86         struct cpufreq_acpi_io *data,
87         unsigned value,
88         unsigned int cpu)
89 {
90         unsigned long i;
91
92         dprintk("extract_clock\n");
93
94         for (i = 0; i < data->acpi_data.state_count; i++) {
95                 if (value == data->acpi_data.states[i].status)
96                         return data->acpi_data.states[i].core_frequency;
97         }
98         return data->acpi_data.states[i-1].core_frequency;
99 }
100
101
102 static unsigned int
103 processor_get_freq (
104         struct cpufreq_acpi_io  *data,
105         unsigned int            cpu)
106 {
107         int                     ret = 0;
108         u32                     value = 0;
109         cpumask_t               saved_mask;
110         unsigned long           clock_freq;
111
112         dprintk("processor_get_freq\n");
113
114         saved_mask = current->cpus_allowed;
115         set_cpus_allowed(current, cpumask_of_cpu(cpu));
116         if (smp_processor_id() != cpu)
117                 goto migrate_end;
118
119         /* processor_get_pstate gets the instantaneous frequency */
120         ret = processor_get_pstate(&value);
121
122         if (ret) {
123                 set_cpus_allowed(current, saved_mask);
124                 printk(KERN_WARNING "get performance failed with error %d\n",
125                        ret);
126                 ret = 0;
127                 goto migrate_end;
128         }
129         clock_freq = extract_clock(data, value, cpu);
130         ret = (clock_freq*1000);
131
132 migrate_end:
133         set_cpus_allowed(current, saved_mask);
134         return ret;
135 }
136
137
138 static int
139 processor_set_freq (
140         struct cpufreq_acpi_io  *data,
141         unsigned int            cpu,
142         int                     state)
143 {
144         int                     ret = 0;
145         u32                     value = 0;
146         struct cpufreq_freqs    cpufreq_freqs;
147         cpumask_t               saved_mask;
148         int                     retval;
149
150         dprintk("processor_set_freq\n");
151
152         saved_mask = current->cpus_allowed;
153         set_cpus_allowed(current, cpumask_of_cpu(cpu));
154         if (smp_processor_id() != cpu) {
155                 retval = -EAGAIN;
156                 goto migrate_end;
157         }
158
159         if (state == data->acpi_data.state) {
160                 if (unlikely(data->resume)) {
161                         dprintk("Called after resume, resetting to P%d\n", state);
162                         data->resume = 0;
163                 } else {
164                         dprintk("Already at target state (P%d)\n", state);
165                         retval = 0;
166                         goto migrate_end;
167                 }
168         }
169
170         dprintk("Transitioning from P%d to P%d\n",
171                 data->acpi_data.state, state);
172
173         /* cpufreq frequency struct */
174         cpufreq_freqs.cpu = cpu;
175         cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
176         cpufreq_freqs.new = data->freq_table[state].frequency;
177
178         /* notify cpufreq */
179         cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
180
181         /*
182          * First we write the target state's 'control' value to the
183          * control_register.
184          */
185
186         value = (u32) data->acpi_data.states[state].control;
187
188         dprintk("Transitioning to state: 0x%08x\n", value);
189
190         ret = processor_set_pstate(value);
191         if (ret) {
192                 unsigned int tmp = cpufreq_freqs.new;
193                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
194                 cpufreq_freqs.new = cpufreq_freqs.old;
195                 cpufreq_freqs.old = tmp;
196                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
197                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
198                 printk(KERN_WARNING "Transition failed with error %d\n", ret);
199                 retval = -ENODEV;
200                 goto migrate_end;
201         }
202
203         cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
204
205         data->acpi_data.state = state;
206
207         retval = 0;
208
209 migrate_end:
210         set_cpus_allowed(current, saved_mask);
211         return (retval);
212 }
213
214
215 static unsigned int
216 acpi_cpufreq_get (
217         unsigned int            cpu)
218 {
219         struct cpufreq_acpi_io *data = acpi_io_data[cpu];
220
221         dprintk("acpi_cpufreq_get\n");
222
223         return processor_get_freq(data, cpu);
224 }
225
226
227 static int
228 acpi_cpufreq_target (
229         struct cpufreq_policy   *policy,
230         unsigned int target_freq,
231         unsigned int relation)
232 {
233         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
234         unsigned int next_state = 0;
235         unsigned int result = 0;
236
237         dprintk("acpi_cpufreq_setpolicy\n");
238
239         result = cpufreq_frequency_table_target(policy,
240                         data->freq_table, target_freq, relation, &next_state);
241         if (result)
242                 return (result);
243
244         result = processor_set_freq(data, policy->cpu, next_state);
245
246         return (result);
247 }
248
249
250 static int
251 acpi_cpufreq_verify (
252         struct cpufreq_policy   *policy)
253 {
254         unsigned int result = 0;
255         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
256
257         dprintk("acpi_cpufreq_verify\n");
258
259         result = cpufreq_frequency_table_verify(policy,
260                         data->freq_table);
261
262         return (result);
263 }
264
265
266 static int
267 acpi_cpufreq_cpu_init (
268         struct cpufreq_policy   *policy)
269 {
270         unsigned int            i;
271         unsigned int            cpu = policy->cpu;
272         struct cpufreq_acpi_io  *data;
273         unsigned int            result = 0;
274
275         dprintk("acpi_cpufreq_cpu_init\n");
276
277         data = kzalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
278         if (!data)
279                 return (-ENOMEM);
280
281         acpi_io_data[cpu] = data;
282
283         result = acpi_processor_register_performance(&data->acpi_data, cpu);
284
285         if (result)
286                 goto err_free;
287
288         /* capability check */
289         if (data->acpi_data.state_count <= 1) {
290                 dprintk("No P-States\n");
291                 result = -ENODEV;
292                 goto err_unreg;
293         }
294
295         if ((data->acpi_data.control_register.space_id !=
296                                         ACPI_ADR_SPACE_FIXED_HARDWARE) ||
297             (data->acpi_data.status_register.space_id !=
298                                         ACPI_ADR_SPACE_FIXED_HARDWARE)) {
299                 dprintk("Unsupported address space [%d, %d]\n",
300                         (u32) (data->acpi_data.control_register.space_id),
301                         (u32) (data->acpi_data.status_register.space_id));
302                 result = -ENODEV;
303                 goto err_unreg;
304         }
305
306         /* alloc freq_table */
307         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
308                                    (data->acpi_data.state_count + 1),
309                                    GFP_KERNEL);
310         if (!data->freq_table) {
311                 result = -ENOMEM;
312                 goto err_unreg;
313         }
314
315         /* detect transition latency */
316         policy->cpuinfo.transition_latency = 0;
317         for (i=0; i<data->acpi_data.state_count; i++) {
318                 if ((data->acpi_data.states[i].transition_latency * 1000) >
319                     policy->cpuinfo.transition_latency) {
320                         policy->cpuinfo.transition_latency =
321                             data->acpi_data.states[i].transition_latency * 1000;
322                 }
323         }
324         policy->cur = processor_get_freq(data, policy->cpu);
325
326         /* table init */
327         for (i = 0; i <= data->acpi_data.state_count; i++)
328         {
329                 data->freq_table[i].index = i;
330                 if (i < data->acpi_data.state_count) {
331                         data->freq_table[i].frequency =
332                               data->acpi_data.states[i].core_frequency * 1000;
333                 } else {
334                         data->freq_table[i].frequency = CPUFREQ_TABLE_END;
335                 }
336         }
337
338         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
339         if (result) {
340                 goto err_freqfree;
341         }
342
343         /* notify BIOS that we exist */
344         acpi_processor_notify_smm(THIS_MODULE);
345
346         printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management "
347                "activated.\n", cpu);
348
349         for (i = 0; i < data->acpi_data.state_count; i++)
350                 dprintk("     %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
351                         (i == data->acpi_data.state?'*':' '), i,
352                         (u32) data->acpi_data.states[i].core_frequency,
353                         (u32) data->acpi_data.states[i].power,
354                         (u32) data->acpi_data.states[i].transition_latency,
355                         (u32) data->acpi_data.states[i].bus_master_latency,
356                         (u32) data->acpi_data.states[i].status,
357                         (u32) data->acpi_data.states[i].control);
358
359         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
360
361         /* the first call to ->target() should result in us actually
362          * writing something to the appropriate registers. */
363         data->resume = 1;
364
365         return (result);
366
367  err_freqfree:
368         kfree(data->freq_table);
369  err_unreg:
370         acpi_processor_unregister_performance(&data->acpi_data, cpu);
371  err_free:
372         kfree(data);
373         acpi_io_data[cpu] = NULL;
374
375         return (result);
376 }
377
378
379 static int
380 acpi_cpufreq_cpu_exit (
381         struct cpufreq_policy   *policy)
382 {
383         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
384
385         dprintk("acpi_cpufreq_cpu_exit\n");
386
387         if (data) {
388                 cpufreq_frequency_table_put_attr(policy->cpu);
389                 acpi_io_data[policy->cpu] = NULL;
390                 acpi_processor_unregister_performance(&data->acpi_data,
391                                                       policy->cpu);
392                 kfree(data);
393         }
394
395         return (0);
396 }
397
398
399 static struct freq_attr* acpi_cpufreq_attr[] = {
400         &cpufreq_freq_attr_scaling_available_freqs,
401         NULL,
402 };
403
404
405 static struct cpufreq_driver acpi_cpufreq_driver = {
406         .verify         = acpi_cpufreq_verify,
407         .target         = acpi_cpufreq_target,
408         .get            = acpi_cpufreq_get,
409         .init           = acpi_cpufreq_cpu_init,
410         .exit           = acpi_cpufreq_cpu_exit,
411         .name           = "acpi-cpufreq",
412         .owner          = THIS_MODULE,
413         .attr           = acpi_cpufreq_attr,
414 };
415
416
417 static int __init
418 acpi_cpufreq_init (void)
419 {
420         dprintk("acpi_cpufreq_init\n");
421
422         return cpufreq_register_driver(&acpi_cpufreq_driver);
423 }
424
425
426 static void __exit
427 acpi_cpufreq_exit (void)
428 {
429         dprintk("acpi_cpufreq_exit\n");
430
431         cpufreq_unregister_driver(&acpi_cpufreq_driver);
432         return;
433 }
434
435
436 late_initcall(acpi_cpufreq_init);
437 module_exit(acpi_cpufreq_exit);
438