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11#include <linux/kernel.h>
12#include <linux/slab.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
25MODULE_AUTHOR("Venkatesh Pallipadi");
26MODULE_DESCRIPTION("ACPI Processor P-States Driver");
27MODULE_LICENSE("GPL");
28
29
30struct cpufreq_acpi_io {
31 struct acpi_processor_performance acpi_data;
32 struct cpufreq_frequency_table *freq_table;
33 unsigned int resume;
34};
35
36static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS];
37
38static struct cpufreq_driver acpi_cpufreq_driver;
39
40
41static int
42processor_set_pstate (
43 u32 value)
44{
45 s64 retval;
46
47 pr_debug("processor_set_pstate\n");
48
49 retval = ia64_pal_set_pstate((u64)value);
50
51 if (retval) {
52 pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n",
53 value, retval);
54 return -ENODEV;
55 }
56 return (int)retval;
57}
58
59
60static int
61processor_get_pstate (
62 u32 *value)
63{
64 u64 pstate_index = 0;
65 s64 retval;
66
67 pr_debug("processor_get_pstate\n");
68
69 retval = ia64_pal_get_pstate(&pstate_index,
70 PAL_GET_PSTATE_TYPE_INSTANT);
71 *value = (u32) pstate_index;
72
73 if (retval)
74 pr_debug("Failed to get current freq with "
75 "error 0x%lx, idx 0x%x\n", retval, *value);
76
77 return (int)retval;
78}
79
80
81
82static unsigned
83extract_clock (
84 struct cpufreq_acpi_io *data,
85 unsigned value,
86 unsigned int cpu)
87{
88 unsigned long i;
89
90 pr_debug("extract_clock\n");
91
92 for (i = 0; i < data->acpi_data.state_count; i++) {
93 if (value == data->acpi_data.states[i].status)
94 return data->acpi_data.states[i].core_frequency;
95 }
96 return data->acpi_data.states[i-1].core_frequency;
97}
98
99
100static unsigned int
101processor_get_freq (
102 struct cpufreq_acpi_io *data,
103 unsigned int cpu)
104{
105 int ret = 0;
106 u32 value = 0;
107 cpumask_t saved_mask;
108 unsigned long clock_freq;
109
110 pr_debug("processor_get_freq\n");
111
112 saved_mask = current->cpus_allowed;
113 set_cpus_allowed_ptr(current, cpumask_of(cpu));
114 if (smp_processor_id() != cpu)
115 goto migrate_end;
116
117
118 ret = processor_get_pstate(&value);
119
120 if (ret) {
121 set_cpus_allowed_ptr(current, &saved_mask);
122 printk(KERN_WARNING "get performance failed with error %d\n",
123 ret);
124 ret = 0;
125 goto migrate_end;
126 }
127 clock_freq = extract_clock(data, value, cpu);
128 ret = (clock_freq*1000);
129
130migrate_end:
131 set_cpus_allowed_ptr(current, &saved_mask);
132 return ret;
133}
134
135
136static int
137processor_set_freq (
138 struct cpufreq_acpi_io *data,
139 struct cpufreq_policy *policy,
140 int state)
141{
142 int ret = 0;
143 u32 value = 0;
144 struct cpufreq_freqs cpufreq_freqs;
145 cpumask_t saved_mask;
146 int retval;
147
148 pr_debug("processor_set_freq\n");
149
150 saved_mask = current->cpus_allowed;
151 set_cpus_allowed_ptr(current, cpumask_of(policy->cpu));
152 if (smp_processor_id() != policy->cpu) {
153 retval = -EAGAIN;
154 goto migrate_end;
155 }
156
157 if (state == data->acpi_data.state) {
158 if (unlikely(data->resume)) {
159 pr_debug("Called after resume, resetting to P%d\n", state);
160 data->resume = 0;
161 } else {
162 pr_debug("Already at target state (P%d)\n", state);
163 retval = 0;
164 goto migrate_end;
165 }
166 }
167
168 pr_debug("Transitioning from P%d to P%d\n",
169 data->acpi_data.state, state);
170
171
172 cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
173 cpufreq_freqs.new = data->freq_table[state].frequency;
174
175
176 cpufreq_notify_transition(policy, &cpufreq_freqs, CPUFREQ_PRECHANGE);
177
178
179
180
181
182
183 value = (u32) data->acpi_data.states[state].control;
184
185 pr_debug("Transitioning to state: 0x%08x\n", value);
186
187 ret = processor_set_pstate(value);
188 if (ret) {
189 unsigned int tmp = cpufreq_freqs.new;
190 cpufreq_notify_transition(policy, &cpufreq_freqs,
191 CPUFREQ_POSTCHANGE);
192 cpufreq_freqs.new = cpufreq_freqs.old;
193 cpufreq_freqs.old = tmp;
194 cpufreq_notify_transition(policy, &cpufreq_freqs,
195 CPUFREQ_PRECHANGE);
196 cpufreq_notify_transition(policy, &cpufreq_freqs,
197 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(policy, &cpufreq_freqs, CPUFREQ_POSTCHANGE);
204
205 data->acpi_data.state = state;
206
207 retval = 0;
208
209migrate_end:
210 set_cpus_allowed_ptr(current, &saved_mask);
211 return (retval);
212}
213
214
215static unsigned int
216acpi_cpufreq_get (
217 unsigned int cpu)
218{
219 struct cpufreq_acpi_io *data = acpi_io_data[cpu];
220
221 pr_debug("acpi_cpufreq_get\n");
222
223 return processor_get_freq(data, cpu);
224}
225
226
227static int
228acpi_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 pr_debug("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, next_state);
245
246 return (result);
247}
248
249
250static int
251acpi_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 pr_debug("acpi_cpufreq_verify\n");
258
259 result = cpufreq_frequency_table_verify(policy,
260 data->freq_table);
261
262 return (result);
263}
264
265
266static int
267acpi_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 pr_debug("acpi_cpufreq_cpu_init\n");
276
277 data = kzalloc(sizeof(*data), 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
289 if (data->acpi_data.state_count <= 1) {
290 pr_debug("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 pr_debug("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
307 data->freq_table = kmalloc(sizeof(*data->freq_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
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
327 for (i = 0; i <= data->acpi_data.state_count; i++)
328 {
329 data->freq_table[i].driver_data = 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
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 pr_debug(" %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
362
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
379static int
380acpi_cpufreq_cpu_exit (
381 struct cpufreq_policy *policy)
382{
383 struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
384
385 pr_debug("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
399static struct freq_attr* acpi_cpufreq_attr[] = {
400 &cpufreq_freq_attr_scaling_available_freqs,
401 NULL,
402};
403
404
405static 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 .attr = acpi_cpufreq_attr,
413};
414
415
416static int __init
417acpi_cpufreq_init (void)
418{
419 pr_debug("acpi_cpufreq_init\n");
420
421 return cpufreq_register_driver(&acpi_cpufreq_driver);
422}
423
424
425static void __exit
426acpi_cpufreq_exit (void)
427{
428 pr_debug("acpi_cpufreq_exit\n");
429
430 cpufreq_unregister_driver(&acpi_cpufreq_driver);
431 return;
432}
433
434
435late_initcall(acpi_cpufreq_init);
436module_exit(acpi_cpufreq_exit);
437
438
