]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blame - drivers/cpufreq/ia64-acpi-cpufreq.c
cpufreq: Implement light weight ->target_index() routine
[mirror_ubuntu-artful-kernel.git] / drivers / cpufreq / ia64-acpi-cpufreq.c
CommitLineData
4db8699b 1/*
4db8699b
VP
2 * This file provides the ACPI based P-state support. This
3 * module works with generic cpufreq infrastructure. Most of
4 * the code is based on i386 version
5 * (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c)
6 *
7 * Copyright (C) 2005 Intel Corp
8 * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
9 */
10
4db8699b 11#include <linux/kernel.h>
5a0e3ad6 12#include <linux/slab.h>
4db8699b
VP
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
4db8699b
VP
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
2d06d8c4 47 pr_debug("processor_set_pstate\n");
4db8699b
VP
48
49 retval = ia64_pal_set_pstate((u64)value);
50
51 if (retval) {
2d06d8c4 52 pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n",
4db8699b
VP
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
2d06d8c4 67 pr_debug("processor_get_pstate\n");
4db8699b 68
17e77b1c
VP
69 retval = ia64_pal_get_pstate(&pstate_index,
70 PAL_GET_PSTATE_TYPE_INSTANT);
4db8699b
VP
71 *value = (u32) pstate_index;
72
73 if (retval)
2d06d8c4 74 pr_debug("Failed to get current freq with "
60192db8 75 "error 0x%lx, idx 0x%x\n", retval, *value);
4db8699b
VP
76
77 return (int)retval;
78}
79
80
81/* To be used only after data->acpi_data is initialized */
82static unsigned
83extract_clock (
84 struct cpufreq_acpi_io *data,
85 unsigned value,
86 unsigned int cpu)
87{
88 unsigned long i;
89
2d06d8c4 90 pr_debug("extract_clock\n");
4db8699b
VP
91
92 for (i = 0; i < data->acpi_data.state_count; i++) {
17e77b1c 93 if (value == data->acpi_data.states[i].status)
4db8699b
VP
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
2d06d8c4 110 pr_debug("processor_get_freq\n");
4db8699b
VP
111
112 saved_mask = current->cpus_allowed;
552dce3a 113 set_cpus_allowed_ptr(current, cpumask_of(cpu));
182fdd22 114 if (smp_processor_id() != cpu)
4db8699b 115 goto migrate_end;
4db8699b 116
17e77b1c 117 /* processor_get_pstate gets the instantaneous frequency */
4db8699b
VP
118 ret = processor_get_pstate(&value);
119
120 if (ret) {
552dce3a 121 set_cpus_allowed_ptr(current, &saved_mask);
4db8699b
VP
122 printk(KERN_WARNING "get performance failed with error %d\n",
123 ret);
182fdd22 124 ret = 0;
4db8699b
VP
125 goto migrate_end;
126 }
127 clock_freq = extract_clock(data, value, cpu);
128 ret = (clock_freq*1000);
129
130migrate_end:
552dce3a 131 set_cpus_allowed_ptr(current, &saved_mask);
4db8699b
VP
132 return ret;
133}
134
135
136static int
137processor_set_freq (
138 struct cpufreq_acpi_io *data,
b43a7ffb 139 struct cpufreq_policy *policy,
4db8699b
VP
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
2d06d8c4 148 pr_debug("processor_set_freq\n");
4db8699b
VP
149
150 saved_mask = current->cpus_allowed;
b43a7ffb
VK
151 set_cpus_allowed_ptr(current, cpumask_of(policy->cpu));
152 if (smp_processor_id() != policy->cpu) {
4db8699b
VP
153 retval = -EAGAIN;
154 goto migrate_end;
155 }
156
157 if (state == data->acpi_data.state) {
158 if (unlikely(data->resume)) {
2d06d8c4 159 pr_debug("Called after resume, resetting to P%d\n", state);
4db8699b
VP
160 data->resume = 0;
161 } else {
2d06d8c4 162 pr_debug("Already at target state (P%d)\n", state);
4db8699b
VP
163 retval = 0;
164 goto migrate_end;
165 }
166 }
167
2d06d8c4 168 pr_debug("Transitioning from P%d to P%d\n",
4db8699b
VP
169 data->acpi_data.state, state);
170
171 /* cpufreq frequency struct */
4db8699b
VP
172 cpufreq_freqs.old = data->freq_table[data->acpi_data.state].frequency;
173 cpufreq_freqs.new = data->freq_table[state].frequency;
174
175 /* notify cpufreq */
b43a7ffb 176 cpufreq_notify_transition(policy, &cpufreq_freqs, CPUFREQ_PRECHANGE);
4db8699b
VP
177
178 /*
179 * First we write the target state's 'control' value to the
180 * control_register.
181 */
182
183 value = (u32) data->acpi_data.states[state].control;
184
2d06d8c4 185 pr_debug("Transitioning to state: 0x%08x\n", value);
4db8699b
VP
186
187 ret = processor_set_pstate(value);
188 if (ret) {
189 unsigned int tmp = cpufreq_freqs.new;
b43a7ffb
VK
190 cpufreq_notify_transition(policy, &cpufreq_freqs,
191 CPUFREQ_POSTCHANGE);
4db8699b
VP
192 cpufreq_freqs.new = cpufreq_freqs.old;
193 cpufreq_freqs.old = tmp;
b43a7ffb
VK
194 cpufreq_notify_transition(policy, &cpufreq_freqs,
195 CPUFREQ_PRECHANGE);
196 cpufreq_notify_transition(policy, &cpufreq_freqs,
197 CPUFREQ_POSTCHANGE);
4db8699b
VP
198 printk(KERN_WARNING "Transition failed with error %d\n", ret);
199 retval = -ENODEV;
200 goto migrate_end;
201 }
202
b43a7ffb 203 cpufreq_notify_transition(policy, &cpufreq_freqs, CPUFREQ_POSTCHANGE);
4db8699b
VP
204
205 data->acpi_data.state = state;
206
207 retval = 0;
208
209migrate_end:
552dce3a 210 set_cpus_allowed_ptr(current, &saved_mask);
4db8699b
VP
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
2d06d8c4 221 pr_debug("acpi_cpufreq_get\n");
4db8699b
VP
222
223 return processor_get_freq(data, cpu);
224}
225
226
227static int
228acpi_cpufreq_target (
229 struct cpufreq_policy *policy,
9c0ebcf7 230 unsigned int index)
4db8699b 231{
9c0ebcf7 232 return processor_set_freq(acpi_io_data[policy->cpu], policy, index);
4db8699b
VP
233}
234
4db8699b
VP
235static int
236acpi_cpufreq_cpu_init (
237 struct cpufreq_policy *policy)
238{
239 unsigned int i;
240 unsigned int cpu = policy->cpu;
241 struct cpufreq_acpi_io *data;
242 unsigned int result = 0;
243
2d06d8c4 244 pr_debug("acpi_cpufreq_cpu_init\n");
4db8699b 245
d5b73cd8 246 data = kzalloc(sizeof(*data), GFP_KERNEL);
4db8699b
VP
247 if (!data)
248 return (-ENOMEM);
249
4db8699b
VP
250 acpi_io_data[cpu] = data;
251
4db8699b 252 result = acpi_processor_register_performance(&data->acpi_data, cpu);
4db8699b
VP
253
254 if (result)
255 goto err_free;
256
257 /* capability check */
258 if (data->acpi_data.state_count <= 1) {
2d06d8c4 259 pr_debug("No P-States\n");
4db8699b
VP
260 result = -ENODEV;
261 goto err_unreg;
262 }
263
264 if ((data->acpi_data.control_register.space_id !=
265 ACPI_ADR_SPACE_FIXED_HARDWARE) ||
266 (data->acpi_data.status_register.space_id !=
267 ACPI_ADR_SPACE_FIXED_HARDWARE)) {
2d06d8c4 268 pr_debug("Unsupported address space [%d, %d]\n",
4db8699b
VP
269 (u32) (data->acpi_data.control_register.space_id),
270 (u32) (data->acpi_data.status_register.space_id));
271 result = -ENODEV;
272 goto err_unreg;
273 }
274
275 /* alloc freq_table */
d5b73cd8 276 data->freq_table = kmalloc(sizeof(*data->freq_table) *
4db8699b
VP
277 (data->acpi_data.state_count + 1),
278 GFP_KERNEL);
279 if (!data->freq_table) {
280 result = -ENOMEM;
281 goto err_unreg;
282 }
283
284 /* detect transition latency */
285 policy->cpuinfo.transition_latency = 0;
286 for (i=0; i<data->acpi_data.state_count; i++) {
287 if ((data->acpi_data.states[i].transition_latency * 1000) >
288 policy->cpuinfo.transition_latency) {
289 policy->cpuinfo.transition_latency =
290 data->acpi_data.states[i].transition_latency * 1000;
291 }
292 }
4db8699b
VP
293
294 /* table init */
295 for (i = 0; i <= data->acpi_data.state_count; i++)
296 {
50701588 297 data->freq_table[i].driver_data = i;
4db8699b
VP
298 if (i < data->acpi_data.state_count) {
299 data->freq_table[i].frequency =
300 data->acpi_data.states[i].core_frequency * 1000;
301 } else {
302 data->freq_table[i].frequency = CPUFREQ_TABLE_END;
303 }
304 }
305
bbe2c170 306 result = cpufreq_table_validate_and_show(policy, data->freq_table);
4db8699b
VP
307 if (result) {
308 goto err_freqfree;
309 }
310
311 /* notify BIOS that we exist */
312 acpi_processor_notify_smm(THIS_MODULE);
313
314 printk(KERN_INFO "acpi-cpufreq: CPU%u - ACPI performance management "
315 "activated.\n", cpu);
316
317 for (i = 0; i < data->acpi_data.state_count; i++)
2d06d8c4 318 pr_debug(" %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n",
4db8699b
VP
319 (i == data->acpi_data.state?'*':' '), i,
320 (u32) data->acpi_data.states[i].core_frequency,
321 (u32) data->acpi_data.states[i].power,
322 (u32) data->acpi_data.states[i].transition_latency,
323 (u32) data->acpi_data.states[i].bus_master_latency,
324 (u32) data->acpi_data.states[i].status,
325 (u32) data->acpi_data.states[i].control);
326
4db8699b
VP
327 /* the first call to ->target() should result in us actually
328 * writing something to the appropriate registers. */
329 data->resume = 1;
330
331 return (result);
332
333 err_freqfree:
334 kfree(data->freq_table);
335 err_unreg:
336 acpi_processor_unregister_performance(&data->acpi_data, cpu);
337 err_free:
338 kfree(data);
339 acpi_io_data[cpu] = NULL;
340
341 return (result);
342}
343
344
345static int
346acpi_cpufreq_cpu_exit (
347 struct cpufreq_policy *policy)
348{
349 struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu];
350
2d06d8c4 351 pr_debug("acpi_cpufreq_cpu_exit\n");
4db8699b
VP
352
353 if (data) {
354 cpufreq_frequency_table_put_attr(policy->cpu);
355 acpi_io_data[policy->cpu] = NULL;
356 acpi_processor_unregister_performance(&data->acpi_data,
357 policy->cpu);
358 kfree(data);
359 }
360
361 return (0);
362}
363
364
4db8699b 365static struct cpufreq_driver acpi_cpufreq_driver = {
59b2413b 366 .verify = cpufreq_generic_frequency_table_verify,
9c0ebcf7 367 .target_index = acpi_cpufreq_target,
4db8699b
VP
368 .get = acpi_cpufreq_get,
369 .init = acpi_cpufreq_cpu_init,
370 .exit = acpi_cpufreq_cpu_exit,
371 .name = "acpi-cpufreq",
59b2413b 372 .attr = cpufreq_generic_attr,
4db8699b
VP
373};
374
375
376static int __init
377acpi_cpufreq_init (void)
378{
2d06d8c4 379 pr_debug("acpi_cpufreq_init\n");
4db8699b
VP
380
381 return cpufreq_register_driver(&acpi_cpufreq_driver);
382}
383
384
385static void __exit
386acpi_cpufreq_exit (void)
387{
2d06d8c4 388 pr_debug("acpi_cpufreq_exit\n");
4db8699b
VP
389
390 cpufreq_unregister_driver(&acpi_cpufreq_driver);
391 return;
392}
393
394
395late_initcall(acpi_cpufreq_init);
396module_exit(acpi_cpufreq_exit);
397