Commit | Line | Data |
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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 | ||
1c5864e2 JP |
11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
12 | ||
4db8699b | 13 | #include <linux/kernel.h> |
5a0e3ad6 | 14 | #include <linux/slab.h> |
4db8699b VP |
15 | #include <linux/module.h> |
16 | #include <linux/init.h> | |
17 | #include <linux/cpufreq.h> | |
18 | #include <linux/proc_fs.h> | |
19 | #include <linux/seq_file.h> | |
20 | #include <asm/io.h> | |
21 | #include <asm/uaccess.h> | |
22 | #include <asm/pal.h> | |
23 | ||
24 | #include <linux/acpi.h> | |
25 | #include <acpi/processor.h> | |
26 | ||
4db8699b VP |
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; | |
4db8699b VP |
34 | unsigned int resume; |
35 | }; | |
36 | ||
37 | static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS]; | |
38 | ||
39 | static struct cpufreq_driver acpi_cpufreq_driver; | |
40 | ||
41 | ||
42 | static int | |
43 | processor_set_pstate ( | |
44 | u32 value) | |
45 | { | |
46 | s64 retval; | |
47 | ||
2d06d8c4 | 48 | pr_debug("processor_set_pstate\n"); |
4db8699b VP |
49 | |
50 | retval = ia64_pal_set_pstate((u64)value); | |
51 | ||
52 | if (retval) { | |
2d06d8c4 | 53 | pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n", |
4db8699b VP |
54 | value, retval); |
55 | return -ENODEV; | |
56 | } | |
57 | return (int)retval; | |
58 | } | |
59 | ||
60 | ||
61 | static int | |
62 | processor_get_pstate ( | |
63 | u32 *value) | |
64 | { | |
65 | u64 pstate_index = 0; | |
66 | s64 retval; | |
67 | ||
2d06d8c4 | 68 | pr_debug("processor_get_pstate\n"); |
4db8699b | 69 | |
17e77b1c VP |
70 | retval = ia64_pal_get_pstate(&pstate_index, |
71 | PAL_GET_PSTATE_TYPE_INSTANT); | |
4db8699b VP |
72 | *value = (u32) pstate_index; |
73 | ||
74 | if (retval) | |
2d06d8c4 | 75 | pr_debug("Failed to get current freq with " |
60192db8 | 76 | "error 0x%lx, idx 0x%x\n", retval, *value); |
4db8699b VP |
77 | |
78 | return (int)retval; | |
79 | } | |
80 | ||
81 | ||
82 | /* To be used only after data->acpi_data is initialized */ | |
83 | static unsigned | |
84 | extract_clock ( | |
85 | struct cpufreq_acpi_io *data, | |
86 | unsigned value, | |
87 | unsigned int cpu) | |
88 | { | |
89 | unsigned long i; | |
90 | ||
2d06d8c4 | 91 | pr_debug("extract_clock\n"); |
4db8699b VP |
92 | |
93 | for (i = 0; i < data->acpi_data.state_count; i++) { | |
17e77b1c | 94 | if (value == data->acpi_data.states[i].status) |
4db8699b VP |
95 | return data->acpi_data.states[i].core_frequency; |
96 | } | |
97 | return data->acpi_data.states[i-1].core_frequency; | |
98 | } | |
99 | ||
100 | ||
101 | static unsigned int | |
102 | processor_get_freq ( | |
103 | struct cpufreq_acpi_io *data, | |
104 | unsigned int cpu) | |
105 | { | |
106 | int ret = 0; | |
107 | u32 value = 0; | |
108 | cpumask_t saved_mask; | |
109 | unsigned long clock_freq; | |
110 | ||
2d06d8c4 | 111 | pr_debug("processor_get_freq\n"); |
4db8699b VP |
112 | |
113 | saved_mask = current->cpus_allowed; | |
552dce3a | 114 | set_cpus_allowed_ptr(current, cpumask_of(cpu)); |
182fdd22 | 115 | if (smp_processor_id() != cpu) |
4db8699b | 116 | goto migrate_end; |
4db8699b | 117 | |
17e77b1c | 118 | /* processor_get_pstate gets the instantaneous frequency */ |
4db8699b VP |
119 | ret = processor_get_pstate(&value); |
120 | ||
121 | if (ret) { | |
552dce3a | 122 | set_cpus_allowed_ptr(current, &saved_mask); |
b49c22a6 | 123 | pr_warn("get performance failed with error %d\n", 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 | ||
130 | migrate_end: | |
552dce3a | 131 | set_cpus_allowed_ptr(current, &saved_mask); |
4db8699b VP |
132 | return ret; |
133 | } | |
134 | ||
135 | ||
136 | static int | |
137 | processor_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; | |
4db8699b VP |
144 | cpumask_t saved_mask; |
145 | int retval; | |
146 | ||
2d06d8c4 | 147 | pr_debug("processor_set_freq\n"); |
4db8699b VP |
148 | |
149 | saved_mask = current->cpus_allowed; | |
b43a7ffb VK |
150 | set_cpus_allowed_ptr(current, cpumask_of(policy->cpu)); |
151 | if (smp_processor_id() != policy->cpu) { | |
4db8699b VP |
152 | retval = -EAGAIN; |
153 | goto migrate_end; | |
154 | } | |
155 | ||
156 | if (state == data->acpi_data.state) { | |
157 | if (unlikely(data->resume)) { | |
2d06d8c4 | 158 | pr_debug("Called after resume, resetting to P%d\n", state); |
4db8699b VP |
159 | data->resume = 0; |
160 | } else { | |
2d06d8c4 | 161 | pr_debug("Already at target state (P%d)\n", state); |
4db8699b VP |
162 | retval = 0; |
163 | goto migrate_end; | |
164 | } | |
165 | } | |
166 | ||
2d06d8c4 | 167 | pr_debug("Transitioning from P%d to P%d\n", |
4db8699b VP |
168 | data->acpi_data.state, state); |
169 | ||
4db8699b VP |
170 | /* |
171 | * First we write the target state's 'control' value to the | |
172 | * control_register. | |
173 | */ | |
174 | ||
175 | value = (u32) data->acpi_data.states[state].control; | |
176 | ||
2d06d8c4 | 177 | pr_debug("Transitioning to state: 0x%08x\n", value); |
4db8699b VP |
178 | |
179 | ret = processor_set_pstate(value); | |
180 | if (ret) { | |
b49c22a6 | 181 | pr_warn("Transition failed with error %d\n", ret); |
4db8699b VP |
182 | retval = -ENODEV; |
183 | goto migrate_end; | |
184 | } | |
185 | ||
4db8699b VP |
186 | data->acpi_data.state = state; |
187 | ||
188 | retval = 0; | |
189 | ||
190 | migrate_end: | |
552dce3a | 191 | set_cpus_allowed_ptr(current, &saved_mask); |
4db8699b VP |
192 | return (retval); |
193 | } | |
194 | ||
195 | ||
196 | static unsigned int | |
197 | acpi_cpufreq_get ( | |
198 | unsigned int cpu) | |
199 | { | |
200 | struct cpufreq_acpi_io *data = acpi_io_data[cpu]; | |
201 | ||
2d06d8c4 | 202 | pr_debug("acpi_cpufreq_get\n"); |
4db8699b VP |
203 | |
204 | return processor_get_freq(data, cpu); | |
205 | } | |
206 | ||
207 | ||
208 | static int | |
209 | acpi_cpufreq_target ( | |
210 | struct cpufreq_policy *policy, | |
9c0ebcf7 | 211 | unsigned int index) |
4db8699b | 212 | { |
9c0ebcf7 | 213 | return processor_set_freq(acpi_io_data[policy->cpu], policy, index); |
4db8699b VP |
214 | } |
215 | ||
4db8699b VP |
216 | static int |
217 | acpi_cpufreq_cpu_init ( | |
218 | struct cpufreq_policy *policy) | |
219 | { | |
220 | unsigned int i; | |
221 | unsigned int cpu = policy->cpu; | |
222 | struct cpufreq_acpi_io *data; | |
223 | unsigned int result = 0; | |
946c14f8 | 224 | struct cpufreq_frequency_table *freq_table; |
4db8699b | 225 | |
2d06d8c4 | 226 | pr_debug("acpi_cpufreq_cpu_init\n"); |
4db8699b | 227 | |
d5b73cd8 | 228 | data = kzalloc(sizeof(*data), GFP_KERNEL); |
4db8699b VP |
229 | if (!data) |
230 | return (-ENOMEM); | |
231 | ||
4db8699b VP |
232 | acpi_io_data[cpu] = data; |
233 | ||
4db8699b | 234 | result = acpi_processor_register_performance(&data->acpi_data, cpu); |
4db8699b VP |
235 | |
236 | if (result) | |
237 | goto err_free; | |
238 | ||
239 | /* capability check */ | |
240 | if (data->acpi_data.state_count <= 1) { | |
2d06d8c4 | 241 | pr_debug("No P-States\n"); |
4db8699b VP |
242 | result = -ENODEV; |
243 | goto err_unreg; | |
244 | } | |
245 | ||
246 | if ((data->acpi_data.control_register.space_id != | |
247 | ACPI_ADR_SPACE_FIXED_HARDWARE) || | |
248 | (data->acpi_data.status_register.space_id != | |
249 | ACPI_ADR_SPACE_FIXED_HARDWARE)) { | |
2d06d8c4 | 250 | pr_debug("Unsupported address space [%d, %d]\n", |
4db8699b VP |
251 | (u32) (data->acpi_data.control_register.space_id), |
252 | (u32) (data->acpi_data.status_register.space_id)); | |
253 | result = -ENODEV; | |
254 | goto err_unreg; | |
255 | } | |
256 | ||
257 | /* alloc freq_table */ | |
946c14f8 | 258 | freq_table = kzalloc(sizeof(*freq_table) * |
4db8699b VP |
259 | (data->acpi_data.state_count + 1), |
260 | GFP_KERNEL); | |
946c14f8 | 261 | if (!freq_table) { |
4db8699b VP |
262 | result = -ENOMEM; |
263 | goto err_unreg; | |
264 | } | |
265 | ||
266 | /* detect transition latency */ | |
267 | policy->cpuinfo.transition_latency = 0; | |
268 | for (i=0; i<data->acpi_data.state_count; i++) { | |
269 | if ((data->acpi_data.states[i].transition_latency * 1000) > | |
270 | policy->cpuinfo.transition_latency) { | |
271 | policy->cpuinfo.transition_latency = | |
272 | data->acpi_data.states[i].transition_latency * 1000; | |
273 | } | |
274 | } | |
4db8699b VP |
275 | |
276 | /* table init */ | |
277 | for (i = 0; i <= data->acpi_data.state_count; i++) | |
278 | { | |
4db8699b | 279 | if (i < data->acpi_data.state_count) { |
946c14f8 | 280 | freq_table[i].frequency = |
4db8699b VP |
281 | data->acpi_data.states[i].core_frequency * 1000; |
282 | } else { | |
946c14f8 | 283 | freq_table[i].frequency = CPUFREQ_TABLE_END; |
4db8699b VP |
284 | } |
285 | } | |
286 | ||
946c14f8 | 287 | result = cpufreq_table_validate_and_show(policy, freq_table); |
4db8699b VP |
288 | if (result) { |
289 | goto err_freqfree; | |
290 | } | |
291 | ||
292 | /* notify BIOS that we exist */ | |
293 | acpi_processor_notify_smm(THIS_MODULE); | |
294 | ||
1c5864e2 | 295 | pr_info("CPU%u - ACPI performance management activated\n", cpu); |
4db8699b VP |
296 | |
297 | for (i = 0; i < data->acpi_data.state_count; i++) | |
2d06d8c4 | 298 | pr_debug(" %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n", |
4db8699b VP |
299 | (i == data->acpi_data.state?'*':' '), i, |
300 | (u32) data->acpi_data.states[i].core_frequency, | |
301 | (u32) data->acpi_data.states[i].power, | |
302 | (u32) data->acpi_data.states[i].transition_latency, | |
303 | (u32) data->acpi_data.states[i].bus_master_latency, | |
304 | (u32) data->acpi_data.states[i].status, | |
305 | (u32) data->acpi_data.states[i].control); | |
306 | ||
4db8699b VP |
307 | /* the first call to ->target() should result in us actually |
308 | * writing something to the appropriate registers. */ | |
309 | data->resume = 1; | |
310 | ||
311 | return (result); | |
312 | ||
313 | err_freqfree: | |
946c14f8 | 314 | kfree(freq_table); |
4db8699b | 315 | err_unreg: |
b2f8dc4c | 316 | acpi_processor_unregister_performance(cpu); |
4db8699b VP |
317 | err_free: |
318 | kfree(data); | |
319 | acpi_io_data[cpu] = NULL; | |
320 | ||
321 | return (result); | |
322 | } | |
323 | ||
324 | ||
325 | static int | |
326 | acpi_cpufreq_cpu_exit ( | |
327 | struct cpufreq_policy *policy) | |
328 | { | |
329 | struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu]; | |
330 | ||
2d06d8c4 | 331 | pr_debug("acpi_cpufreq_cpu_exit\n"); |
4db8699b VP |
332 | |
333 | if (data) { | |
4db8699b | 334 | acpi_io_data[policy->cpu] = NULL; |
b2f8dc4c | 335 | acpi_processor_unregister_performance(policy->cpu); |
555f3fe9 | 336 | kfree(policy->freq_table); |
4db8699b VP |
337 | kfree(data); |
338 | } | |
339 | ||
340 | return (0); | |
341 | } | |
342 | ||
343 | ||
4db8699b | 344 | static struct cpufreq_driver acpi_cpufreq_driver = { |
59b2413b | 345 | .verify = cpufreq_generic_frequency_table_verify, |
9c0ebcf7 | 346 | .target_index = acpi_cpufreq_target, |
4db8699b VP |
347 | .get = acpi_cpufreq_get, |
348 | .init = acpi_cpufreq_cpu_init, | |
349 | .exit = acpi_cpufreq_cpu_exit, | |
350 | .name = "acpi-cpufreq", | |
59b2413b | 351 | .attr = cpufreq_generic_attr, |
4db8699b VP |
352 | }; |
353 | ||
354 | ||
355 | static int __init | |
356 | acpi_cpufreq_init (void) | |
357 | { | |
2d06d8c4 | 358 | pr_debug("acpi_cpufreq_init\n"); |
4db8699b VP |
359 | |
360 | return cpufreq_register_driver(&acpi_cpufreq_driver); | |
361 | } | |
362 | ||
363 | ||
364 | static void __exit | |
365 | acpi_cpufreq_exit (void) | |
366 | { | |
2d06d8c4 | 367 | pr_debug("acpi_cpufreq_exit\n"); |
4db8699b VP |
368 | |
369 | cpufreq_unregister_driver(&acpi_cpufreq_driver); | |
370 | return; | |
371 | } | |
372 | ||
373 | ||
374 | late_initcall(acpi_cpufreq_init); | |
375 | module_exit(acpi_cpufreq_exit); | |
376 |