Pull sn-recursive-flags-for-select-builds into release branch
[linux-2.6] / 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/config.h>
13 #include <linux/kernel.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/cpufreq.h>
17 #include <linux/proc_fs.h>
18 #include <linux/seq_file.h>
19 #include <asm/io.h>
20 #include <asm/uaccess.h>
21 #include <asm/pal.h>
22
23 #include <linux/acpi.h>
24 #include <acpi/processor.h>
25
26 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "acpi-cpufreq", msg)
27
28 MODULE_AUTHOR("Venkatesh Pallipadi");
29 MODULE_DESCRIPTION("ACPI Processor P-States Driver");
30 MODULE_LICENSE("GPL");
31
32
33 struct cpufreq_acpi_io {
34         struct acpi_processor_performance       acpi_data;
35         struct cpufreq_frequency_table          *freq_table;
36         unsigned int                            resume;
37 };
38
39 static struct cpufreq_acpi_io   *acpi_io_data[NR_CPUS];
40
41 static struct cpufreq_driver acpi_cpufreq_driver;
42
43
44 static int
45 processor_set_pstate (
46         u32     value)
47 {
48         s64 retval;
49
50         dprintk("processor_set_pstate\n");
51
52         retval = ia64_pal_set_pstate((u64)value);
53
54         if (retval) {
55                 dprintk("Failed to set freq to 0x%x, with error 0x%x\n",
56                         value, retval);
57                 return -ENODEV;
58         }
59         return (int)retval;
60 }
61
62
63 static int
64 processor_get_pstate (
65         u32     *value)
66 {
67         u64     pstate_index = 0;
68         s64     retval;
69
70         dprintk("processor_get_pstate\n");
71
72         retval = ia64_pal_get_pstate(&pstate_index);
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].control)
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                 ret = -EAGAIN;
118                 goto migrate_end;
119         }
120
121         /*
122          * processor_get_pstate gets the average frequency since the
123          * last get. So, do two PAL_get_freq()...
124          */
125         ret = processor_get_pstate(&value);
126         ret = processor_get_pstate(&value);
127
128         if (ret) {
129                 set_cpus_allowed(current, saved_mask);
130                 printk(KERN_WARNING "get performance failed with error %d\n",
131                        ret);
132                 ret = -EAGAIN;
133                 goto migrate_end;
134         }
135         clock_freq = extract_clock(data, value, cpu);
136         ret = (clock_freq*1000);
137
138 migrate_end:
139         set_cpus_allowed(current, saved_mask);
140         return ret;
141 }
142
143
144 static int
145 processor_set_freq (
146         struct cpufreq_acpi_io  *data,
147         unsigned int            cpu,
148         int                     state)
149 {
150         int                     ret = 0;
151         u32                     value = 0;
152         struct cpufreq_freqs    cpufreq_freqs;
153         cpumask_t               saved_mask;
154         int                     retval;
155
156         dprintk("processor_set_freq\n");
157
158         saved_mask = current->cpus_allowed;
159         set_cpus_allowed(current, cpumask_of_cpu(cpu));
160         if (smp_processor_id() != cpu) {
161                 retval = -EAGAIN;
162                 goto migrate_end;
163         }
164
165         if (state == data->acpi_data.state) {
166                 if (unlikely(data->resume)) {
167                         dprintk("Called after resume, resetting to P%d\n", state);
168                         data->resume = 0;
169                 } else {
170                         dprintk("Already at target state (P%d)\n", state);
171                         retval = 0;
172                         goto migrate_end;
173                 }
174         }
175
176         dprintk("Transitioning from P%d to P%d\n",
177                 data->acpi_data.state, state);
178
179         /* cpufreq frequency struct */
180         cpufreq_freqs.cpu = cpu;
181         cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
182         cpufreq_freqs.new = data->freq_table[state].frequency;
183
184         /* notify cpufreq */
185         cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
186
187         /*
188          * First we write the target state's 'control' value to the
189          * control_register.
190          */
191
192         value = (u32) data->acpi_data.states[state].control;
193
194         dprintk("Transitioning to state: 0x%08x\n", value);
195
196         ret = processor_set_pstate(value);
197         if (ret) {
198                 unsigned int tmp = cpufreq_freqs.new;
199                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
200                 cpufreq_freqs.new = cpufreq_freqs.old;
201                 cpufreq_freqs.old = tmp;
202                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_PRECHANGE);
203                 cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
204                 printk(KERN_WARNING "Transition failed with error %d\n", ret);
205                 retval = -ENODEV;
206                 goto migrate_end;
207         }
208
209         cpufreq_notify_transition(&cpufreq_freqs, CPUFREQ_POSTCHANGE);
210
211         data->acpi_data.state = state;
212
213         retval = 0;
214
215 migrate_end:
216         set_cpus_allowed(current, saved_mask);
217         return (retval);
218 }
219
220
221 static unsigned int
222 acpi_cpufreq_get (
223         unsigned int            cpu)
224 {
225         struct cpufreq_acpi_io *data = acpi_io_data[cpu];
226
227         dprintk("acpi_cpufreq_get\n");
228
229         return processor_get_freq(data, cpu);
230 }
231
232
233 static int
234 acpi_cpufreq_target (
235         struct cpufreq_policy   *policy,
236         unsigned int target_freq,
237         unsigned int relation)
238 {
239         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
240         unsigned int next_state = 0;
241         unsigned int result = 0;
242
243         dprintk("acpi_cpufreq_setpolicy\n");
244
245         result = cpufreq_frequency_table_target(policy,
246                         data->freq_table, target_freq, relation, &next_state);
247         if (result)
248                 return (result);
249
250         result = processor_set_freq(data, policy->cpu, next_state);
251
252         return (result);
253 }
254
255
256 static int
257 acpi_cpufreq_verify (
258         struct cpufreq_policy   *policy)
259 {
260         unsigned int result = 0;
261         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
262
263         dprintk("acpi_cpufreq_verify\n");
264
265         result = cpufreq_frequency_table_verify(policy,
266                         data->freq_table);
267
268         return (result);
269 }
270
271
272 static int
273 acpi_cpufreq_cpu_init (
274         struct cpufreq_policy   *policy)
275 {
276         unsigned int            i;
277         unsigned int            cpu = policy->cpu;
278         struct cpufreq_acpi_io  *data;
279         unsigned int            result = 0;
280
281         dprintk("acpi_cpufreq_cpu_init\n");
282
283         data = kmalloc(sizeof(struct cpufreq_acpi_io), GFP_KERNEL);
284         if (!data)
285                 return (-ENOMEM);
286
287         memset(data, 0, sizeof(struct cpufreq_acpi_io));
288
289         acpi_io_data[cpu] = data;
290
291         result = acpi_processor_register_performance(&data->acpi_data, cpu);
292
293         if (result)
294                 goto err_free;
295
296         /* capability check */
297         if (data->acpi_data.state_count <= 1) {
298                 dprintk("No P-States\n");
299                 result = -ENODEV;
300                 goto err_unreg;
301         }
302
303         if ((data->acpi_data.control_register.space_id !=
304                                         ACPI_ADR_SPACE_FIXED_HARDWARE) ||
305             (data->acpi_data.status_register.space_id !=
306                                         ACPI_ADR_SPACE_FIXED_HARDWARE)) {
307                 dprintk("Unsupported address space [%d, %d]\n",
308                         (u32) (data->acpi_data.control_register.space_id),
309                         (u32) (data->acpi_data.status_register.space_id));
310                 result = -ENODEV;
311                 goto err_unreg;
312         }
313
314         /* alloc freq_table */
315         data->freq_table = kmalloc(sizeof(struct cpufreq_frequency_table) *
316                                    (data->acpi_data.state_count + 1),
317                                    GFP_KERNEL);
318         if (!data->freq_table) {
319                 result = -ENOMEM;
320                 goto err_unreg;
321         }
322
323         /* detect transition latency */
324         policy->cpuinfo.transition_latency = 0;
325         for (i=0; i<data->acpi_data.state_count; i++) {
326                 if ((data->acpi_data.states[i].transition_latency * 1000) >
327                     policy->cpuinfo.transition_latency) {
328                         policy->cpuinfo.transition_latency =
329                             data->acpi_data.states[i].transition_latency * 1000;
330                 }
331         }
332         policy->governor = CPUFREQ_DEFAULT_GOVERNOR;
333
334         policy->cur = processor_get_freq(data, policy->cpu);
335
336         /* table init */
337         for (i = 0; i <= data->acpi_data.state_count; i++)
338         {
339                 data->freq_table[i].index = i;
340                 if (i < data->acpi_data.state_count) {
341                         data->freq_table[i].frequency =
342                               data->acpi_data.states[i].core_frequency * 1000;
343                 } else {
344                         data->freq_table[i].frequency = CPUFREQ_TABLE_END;
345                 }
346         }
347
348         result = cpufreq_frequency_table_cpuinfo(policy, data->freq_table);
349         if (result) {
350                 goto err_freqfree;
351         }
352
353         /* notify BIOS that we exist */
354         acpi_processor_notify_smm(THIS_MODULE);
355
356         printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management "
357                "activated.\n", cpu);
358
359         for (i = 0; i < data->acpi_data.state_count; i++)
360                 dprintk("     %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
361                         (i == data->acpi_data.state?'*':' '), i,
362                         (u32) data->acpi_data.states[i].core_frequency,
363                         (u32) data->acpi_data.states[i].power,
364                         (u32) data->acpi_data.states[i].transition_latency,
365                         (u32) data->acpi_data.states[i].bus_master_latency,
366                         (u32) data->acpi_data.states[i].status,
367                         (u32) data->acpi_data.states[i].control);
368
369         cpufreq_frequency_table_get_attr(data->freq_table, policy->cpu);
370
371         /* the first call to ->target() should result in us actually
372          * writing something to the appropriate registers. */
373         data->resume = 1;
374
375         return (result);
376
377  err_freqfree:
378         kfree(data->freq_table);
379  err_unreg:
380         acpi_processor_unregister_performance(&data->acpi_data, cpu);
381  err_free:
382         kfree(data);
383         acpi_io_data[cpu] = NULL;
384
385         return (result);
386 }
387
388
389 static int
390 acpi_cpufreq_cpu_exit (
391         struct cpufreq_policy   *policy)
392 {
393         struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
394
395         dprintk("acpi_cpufreq_cpu_exit\n");
396
397         if (data) {
398                 cpufreq_frequency_table_put_attr(policy->cpu);
399                 acpi_io_data[policy->cpu] = NULL;
400                 acpi_processor_unregister_performance(&data->acpi_data,
401                                                       policy->cpu);
402                 kfree(data);
403         }
404
405         return (0);
406 }
407
408
409 static struct freq_attr* acpi_cpufreq_attr[] = {
410         &cpufreq_freq_attr_scaling_available_freqs,
411         NULL,
412 };
413
414
415 static struct cpufreq_driver acpi_cpufreq_driver = {
416         .verify         = acpi_cpufreq_verify,
417         .target         = acpi_cpufreq_target,
418         .get            = acpi_cpufreq_get,
419         .init           = acpi_cpufreq_cpu_init,
420         .exit           = acpi_cpufreq_cpu_exit,
421         .name           = "acpi-cpufreq",
422         .owner          = THIS_MODULE,
423         .attr           = acpi_cpufreq_attr,
424 };
425
426
427 static int __init
428 acpi_cpufreq_init (void)
429 {
430         dprintk("acpi_cpufreq_init\n");
431
432         return cpufreq_register_driver(&acpi_cpufreq_driver);
433 }
434
435
436 static void __exit
437 acpi_cpufreq_exit (void)
438 {
439         dprintk("acpi_cpufreq_exit\n");
440
441         cpufreq_unregister_driver(&acpi_cpufreq_driver);
442         return;
443 }
444
445
446 late_initcall(acpi_cpufreq_init);
447 module_exit(acpi_cpufreq_exit);
448