]>
Commit | Line | Data |
---|---|---|
1 | /* | |
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 | ||
11 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt | |
12 | ||
13 | #include <linux/kernel.h> | |
14 | #include <linux/slab.h> | |
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 <linux/uaccess.h> | |
22 | #include <asm/pal.h> | |
23 | ||
24 | #include <linux/acpi.h> | |
25 | #include <acpi/processor.h> | |
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 | unsigned int resume; | |
35 | }; | |
36 | ||
37 | struct cpufreq_acpi_req { | |
38 | unsigned int cpu; | |
39 | unsigned int state; | |
40 | }; | |
41 | ||
42 | static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS]; | |
43 | ||
44 | static struct cpufreq_driver acpi_cpufreq_driver; | |
45 | ||
46 | ||
47 | static int | |
48 | processor_set_pstate ( | |
49 | u32 value) | |
50 | { | |
51 | s64 retval; | |
52 | ||
53 | pr_debug("processor_set_pstate\n"); | |
54 | ||
55 | retval = ia64_pal_set_pstate((u64)value); | |
56 | ||
57 | if (retval) { | |
58 | pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n", | |
59 | value, retval); | |
60 | return -ENODEV; | |
61 | } | |
62 | return (int)retval; | |
63 | } | |
64 | ||
65 | ||
66 | static int | |
67 | processor_get_pstate ( | |
68 | u32 *value) | |
69 | { | |
70 | u64 pstate_index = 0; | |
71 | s64 retval; | |
72 | ||
73 | pr_debug("processor_get_pstate\n"); | |
74 | ||
75 | retval = ia64_pal_get_pstate(&pstate_index, | |
76 | PAL_GET_PSTATE_TYPE_INSTANT); | |
77 | *value = (u32) pstate_index; | |
78 | ||
79 | if (retval) | |
80 | pr_debug("Failed to get current freq with " | |
81 | "error 0x%lx, idx 0x%x\n", retval, *value); | |
82 | ||
83 | return (int)retval; | |
84 | } | |
85 | ||
86 | ||
87 | /* To be used only after data->acpi_data is initialized */ | |
88 | static unsigned | |
89 | extract_clock ( | |
90 | struct cpufreq_acpi_io *data, | |
91 | unsigned value) | |
92 | { | |
93 | unsigned long i; | |
94 | ||
95 | pr_debug("extract_clock\n"); | |
96 | ||
97 | for (i = 0; i < data->acpi_data.state_count; i++) { | |
98 | if (value == data->acpi_data.states[i].status) | |
99 | return data->acpi_data.states[i].core_frequency; | |
100 | } | |
101 | return data->acpi_data.states[i-1].core_frequency; | |
102 | } | |
103 | ||
104 | ||
105 | static long | |
106 | processor_get_freq ( | |
107 | void *arg) | |
108 | { | |
109 | struct cpufreq_acpi_req *req = arg; | |
110 | unsigned int cpu = req->cpu; | |
111 | struct cpufreq_acpi_io *data = acpi_io_data[cpu]; | |
112 | u32 value; | |
113 | int ret; | |
114 | ||
115 | pr_debug("processor_get_freq\n"); | |
116 | if (smp_processor_id() != cpu) | |
117 | return -EAGAIN; | |
118 | ||
119 | /* processor_get_pstate gets the instantaneous frequency */ | |
120 | ret = processor_get_pstate(&value); | |
121 | if (ret) { | |
122 | pr_warn("get performance failed with error %d\n", ret); | |
123 | return ret; | |
124 | } | |
125 | return 1000 * extract_clock(data, value); | |
126 | } | |
127 | ||
128 | ||
129 | static long | |
130 | processor_set_freq ( | |
131 | void *arg) | |
132 | { | |
133 | struct cpufreq_acpi_req *req = arg; | |
134 | unsigned int cpu = req->cpu; | |
135 | struct cpufreq_acpi_io *data = acpi_io_data[cpu]; | |
136 | int ret, state = req->state; | |
137 | u32 value; | |
138 | ||
139 | pr_debug("processor_set_freq\n"); | |
140 | if (smp_processor_id() != cpu) | |
141 | return -EAGAIN; | |
142 | ||
143 | if (state == data->acpi_data.state) { | |
144 | if (unlikely(data->resume)) { | |
145 | pr_debug("Called after resume, resetting to P%d\n", state); | |
146 | data->resume = 0; | |
147 | } else { | |
148 | pr_debug("Already at target state (P%d)\n", state); | |
149 | return 0; | |
150 | } | |
151 | } | |
152 | ||
153 | pr_debug("Transitioning from P%d to P%d\n", | |
154 | data->acpi_data.state, state); | |
155 | ||
156 | /* | |
157 | * First we write the target state's 'control' value to the | |
158 | * control_register. | |
159 | */ | |
160 | value = (u32) data->acpi_data.states[state].control; | |
161 | ||
162 | pr_debug("Transitioning to state: 0x%08x\n", value); | |
163 | ||
164 | ret = processor_set_pstate(value); | |
165 | if (ret) { | |
166 | pr_warn("Transition failed with error %d\n", ret); | |
167 | return -ENODEV; | |
168 | } | |
169 | ||
170 | data->acpi_data.state = state; | |
171 | return 0; | |
172 | } | |
173 | ||
174 | ||
175 | static unsigned int | |
176 | acpi_cpufreq_get ( | |
177 | unsigned int cpu) | |
178 | { | |
179 | struct cpufreq_acpi_req req; | |
180 | long ret; | |
181 | ||
182 | req.cpu = cpu; | |
183 | ret = work_on_cpu(cpu, processor_get_freq, &req); | |
184 | ||
185 | return ret > 0 ? (unsigned int) ret : 0; | |
186 | } | |
187 | ||
188 | ||
189 | static int | |
190 | acpi_cpufreq_target ( | |
191 | struct cpufreq_policy *policy, | |
192 | unsigned int index) | |
193 | { | |
194 | struct cpufreq_acpi_req req; | |
195 | ||
196 | req.cpu = policy->cpu; | |
197 | req.state = index; | |
198 | ||
199 | return work_on_cpu(req.cpu, processor_set_freq, &req); | |
200 | } | |
201 | ||
202 | static int | |
203 | acpi_cpufreq_cpu_init ( | |
204 | struct cpufreq_policy *policy) | |
205 | { | |
206 | unsigned int i; | |
207 | unsigned int cpu = policy->cpu; | |
208 | struct cpufreq_acpi_io *data; | |
209 | unsigned int result = 0; | |
210 | struct cpufreq_frequency_table *freq_table; | |
211 | ||
212 | pr_debug("acpi_cpufreq_cpu_init\n"); | |
213 | ||
214 | data = kzalloc(sizeof(*data), GFP_KERNEL); | |
215 | if (!data) | |
216 | return (-ENOMEM); | |
217 | ||
218 | acpi_io_data[cpu] = data; | |
219 | ||
220 | result = acpi_processor_register_performance(&data->acpi_data, cpu); | |
221 | ||
222 | if (result) | |
223 | goto err_free; | |
224 | ||
225 | /* capability check */ | |
226 | if (data->acpi_data.state_count <= 1) { | |
227 | pr_debug("No P-States\n"); | |
228 | result = -ENODEV; | |
229 | goto err_unreg; | |
230 | } | |
231 | ||
232 | if ((data->acpi_data.control_register.space_id != | |
233 | ACPI_ADR_SPACE_FIXED_HARDWARE) || | |
234 | (data->acpi_data.status_register.space_id != | |
235 | ACPI_ADR_SPACE_FIXED_HARDWARE)) { | |
236 | pr_debug("Unsupported address space [%d, %d]\n", | |
237 | (u32) (data->acpi_data.control_register.space_id), | |
238 | (u32) (data->acpi_data.status_register.space_id)); | |
239 | result = -ENODEV; | |
240 | goto err_unreg; | |
241 | } | |
242 | ||
243 | /* alloc freq_table */ | |
244 | freq_table = kzalloc(sizeof(*freq_table) * | |
245 | (data->acpi_data.state_count + 1), | |
246 | GFP_KERNEL); | |
247 | if (!freq_table) { | |
248 | result = -ENOMEM; | |
249 | goto err_unreg; | |
250 | } | |
251 | ||
252 | /* detect transition latency */ | |
253 | policy->cpuinfo.transition_latency = 0; | |
254 | for (i=0; i<data->acpi_data.state_count; i++) { | |
255 | if ((data->acpi_data.states[i].transition_latency * 1000) > | |
256 | policy->cpuinfo.transition_latency) { | |
257 | policy->cpuinfo.transition_latency = | |
258 | data->acpi_data.states[i].transition_latency * 1000; | |
259 | } | |
260 | } | |
261 | ||
262 | /* table init */ | |
263 | for (i = 0; i <= data->acpi_data.state_count; i++) | |
264 | { | |
265 | if (i < data->acpi_data.state_count) { | |
266 | freq_table[i].frequency = | |
267 | data->acpi_data.states[i].core_frequency * 1000; | |
268 | } else { | |
269 | freq_table[i].frequency = CPUFREQ_TABLE_END; | |
270 | } | |
271 | } | |
272 | ||
273 | result = cpufreq_table_validate_and_show(policy, freq_table); | |
274 | if (result) { | |
275 | goto err_freqfree; | |
276 | } | |
277 | ||
278 | /* notify BIOS that we exist */ | |
279 | acpi_processor_notify_smm(THIS_MODULE); | |
280 | ||
281 | pr_info("CPU%u - ACPI performance management activated\n", cpu); | |
282 | ||
283 | for (i = 0; i < data->acpi_data.state_count; i++) | |
284 | pr_debug(" %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n", | |
285 | (i == data->acpi_data.state?'*':' '), i, | |
286 | (u32) data->acpi_data.states[i].core_frequency, | |
287 | (u32) data->acpi_data.states[i].power, | |
288 | (u32) data->acpi_data.states[i].transition_latency, | |
289 | (u32) data->acpi_data.states[i].bus_master_latency, | |
290 | (u32) data->acpi_data.states[i].status, | |
291 | (u32) data->acpi_data.states[i].control); | |
292 | ||
293 | /* the first call to ->target() should result in us actually | |
294 | * writing something to the appropriate registers. */ | |
295 | data->resume = 1; | |
296 | ||
297 | return (result); | |
298 | ||
299 | err_freqfree: | |
300 | kfree(freq_table); | |
301 | err_unreg: | |
302 | acpi_processor_unregister_performance(cpu); | |
303 | err_free: | |
304 | kfree(data); | |
305 | acpi_io_data[cpu] = NULL; | |
306 | ||
307 | return (result); | |
308 | } | |
309 | ||
310 | ||
311 | static int | |
312 | acpi_cpufreq_cpu_exit ( | |
313 | struct cpufreq_policy *policy) | |
314 | { | |
315 | struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu]; | |
316 | ||
317 | pr_debug("acpi_cpufreq_cpu_exit\n"); | |
318 | ||
319 | if (data) { | |
320 | acpi_io_data[policy->cpu] = NULL; | |
321 | acpi_processor_unregister_performance(policy->cpu); | |
322 | kfree(policy->freq_table); | |
323 | kfree(data); | |
324 | } | |
325 | ||
326 | return (0); | |
327 | } | |
328 | ||
329 | ||
330 | static struct cpufreq_driver acpi_cpufreq_driver = { | |
331 | .verify = cpufreq_generic_frequency_table_verify, | |
332 | .target_index = acpi_cpufreq_target, | |
333 | .get = acpi_cpufreq_get, | |
334 | .init = acpi_cpufreq_cpu_init, | |
335 | .exit = acpi_cpufreq_cpu_exit, | |
336 | .name = "acpi-cpufreq", | |
337 | .attr = cpufreq_generic_attr, | |
338 | }; | |
339 | ||
340 | ||
341 | static int __init | |
342 | acpi_cpufreq_init (void) | |
343 | { | |
344 | pr_debug("acpi_cpufreq_init\n"); | |
345 | ||
346 | return cpufreq_register_driver(&acpi_cpufreq_driver); | |
347 | } | |
348 | ||
349 | ||
350 | static void __exit | |
351 | acpi_cpufreq_exit (void) | |
352 | { | |
353 | pr_debug("acpi_cpufreq_exit\n"); | |
354 | ||
355 | cpufreq_unregister_driver(&acpi_cpufreq_driver); | |
356 | return; | |
357 | } | |
358 | ||
359 | ||
360 | late_initcall(acpi_cpufreq_init); | |
361 | module_exit(acpi_cpufreq_exit); | |
362 |