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