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> | |
4db8699b | 19 | #include <asm/io.h> |
7c0f6ba6 | 20 | #include <linux/uaccess.h> |
4db8699b VP |
21 | #include <asm/pal.h> |
22 | ||
23 | #include <linux/acpi.h> | |
24 | #include <acpi/processor.h> | |
25 | ||
4db8699b VP |
26 | MODULE_AUTHOR("Venkatesh Pallipadi"); |
27 | MODULE_DESCRIPTION("ACPI Processor P-States Driver"); | |
28 | MODULE_LICENSE("GPL"); | |
29 | ||
4db8699b VP |
30 | struct cpufreq_acpi_io { |
31 | struct acpi_processor_performance acpi_data; | |
4db8699b VP |
32 | unsigned int resume; |
33 | }; | |
34 | ||
38f05ed0 TG |
35 | struct cpufreq_acpi_req { |
36 | unsigned int cpu; | |
37 | unsigned int state; | |
38 | }; | |
39 | ||
4db8699b VP |
40 | static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS]; |
41 | ||
42 | static struct cpufreq_driver acpi_cpufreq_driver; | |
43 | ||
44 | ||
45 | static int | |
46 | processor_set_pstate ( | |
47 | u32 value) | |
48 | { | |
49 | s64 retval; | |
50 | ||
2d06d8c4 | 51 | pr_debug("processor_set_pstate\n"); |
4db8699b VP |
52 | |
53 | retval = ia64_pal_set_pstate((u64)value); | |
54 | ||
55 | if (retval) { | |
2d06d8c4 | 56 | pr_debug("Failed to set freq to 0x%x, with error 0x%lx\n", |
4db8699b VP |
57 | value, retval); |
58 | return -ENODEV; | |
59 | } | |
60 | return (int)retval; | |
61 | } | |
62 | ||
63 | ||
64 | static int | |
65 | processor_get_pstate ( | |
66 | u32 *value) | |
67 | { | |
68 | u64 pstate_index = 0; | |
69 | s64 retval; | |
70 | ||
2d06d8c4 | 71 | pr_debug("processor_get_pstate\n"); |
4db8699b | 72 | |
17e77b1c VP |
73 | retval = ia64_pal_get_pstate(&pstate_index, |
74 | PAL_GET_PSTATE_TYPE_INSTANT); | |
4db8699b VP |
75 | *value = (u32) pstate_index; |
76 | ||
77 | if (retval) | |
2d06d8c4 | 78 | pr_debug("Failed to get current freq with " |
60192db8 | 79 | "error 0x%lx, idx 0x%x\n", retval, *value); |
4db8699b VP |
80 | |
81 | return (int)retval; | |
82 | } | |
83 | ||
84 | ||
85 | /* To be used only after data->acpi_data is initialized */ | |
86 | static unsigned | |
87 | extract_clock ( | |
88 | struct cpufreq_acpi_io *data, | |
38f05ed0 | 89 | unsigned value) |
4db8699b VP |
90 | { |
91 | unsigned long i; | |
92 | ||
2d06d8c4 | 93 | pr_debug("extract_clock\n"); |
4db8699b VP |
94 | |
95 | for (i = 0; i < data->acpi_data.state_count; i++) { | |
17e77b1c | 96 | if (value == data->acpi_data.states[i].status) |
4db8699b VP |
97 | return data->acpi_data.states[i].core_frequency; |
98 | } | |
99 | return data->acpi_data.states[i-1].core_frequency; | |
100 | } | |
101 | ||
102 | ||
38f05ed0 | 103 | static long |
4db8699b | 104 | processor_get_freq ( |
38f05ed0 | 105 | void *arg) |
4db8699b | 106 | { |
38f05ed0 TG |
107 | struct cpufreq_acpi_req *req = arg; |
108 | unsigned int cpu = req->cpu; | |
109 | struct cpufreq_acpi_io *data = acpi_io_data[cpu]; | |
110 | u32 value; | |
111 | int ret; | |
4db8699b | 112 | |
2d06d8c4 | 113 | pr_debug("processor_get_freq\n"); |
182fdd22 | 114 | if (smp_processor_id() != cpu) |
38f05ed0 | 115 | return -EAGAIN; |
4db8699b | 116 | |
17e77b1c | 117 | /* processor_get_pstate gets the instantaneous frequency */ |
4db8699b | 118 | ret = processor_get_pstate(&value); |
4db8699b | 119 | if (ret) { |
b49c22a6 | 120 | pr_warn("get performance failed with error %d\n", ret); |
38f05ed0 | 121 | return ret; |
4db8699b | 122 | } |
38f05ed0 | 123 | return 1000 * extract_clock(data, value); |
4db8699b VP |
124 | } |
125 | ||
126 | ||
38f05ed0 | 127 | static long |
4db8699b | 128 | processor_set_freq ( |
38f05ed0 | 129 | void *arg) |
4db8699b | 130 | { |
38f05ed0 TG |
131 | struct cpufreq_acpi_req *req = arg; |
132 | unsigned int cpu = req->cpu; | |
133 | struct cpufreq_acpi_io *data = acpi_io_data[cpu]; | |
134 | int ret, state = req->state; | |
135 | u32 value; | |
4db8699b | 136 | |
2d06d8c4 | 137 | pr_debug("processor_set_freq\n"); |
38f05ed0 TG |
138 | if (smp_processor_id() != cpu) |
139 | return -EAGAIN; | |
4db8699b VP |
140 | |
141 | if (state == data->acpi_data.state) { | |
142 | if (unlikely(data->resume)) { | |
2d06d8c4 | 143 | pr_debug("Called after resume, resetting to P%d\n", state); |
4db8699b VP |
144 | data->resume = 0; |
145 | } else { | |
2d06d8c4 | 146 | pr_debug("Already at target state (P%d)\n", state); |
38f05ed0 | 147 | return 0; |
4db8699b VP |
148 | } |
149 | } | |
150 | ||
2d06d8c4 | 151 | pr_debug("Transitioning from P%d to P%d\n", |
4db8699b VP |
152 | data->acpi_data.state, state); |
153 | ||
4db8699b VP |
154 | /* |
155 | * First we write the target state's 'control' value to the | |
156 | * control_register. | |
157 | */ | |
4db8699b VP |
158 | value = (u32) data->acpi_data.states[state].control; |
159 | ||
2d06d8c4 | 160 | pr_debug("Transitioning to state: 0x%08x\n", value); |
4db8699b VP |
161 | |
162 | ret = processor_set_pstate(value); | |
163 | if (ret) { | |
b49c22a6 | 164 | pr_warn("Transition failed with error %d\n", ret); |
38f05ed0 | 165 | return -ENODEV; |
4db8699b VP |
166 | } |
167 | ||
4db8699b | 168 | data->acpi_data.state = state; |
38f05ed0 | 169 | return 0; |
4db8699b VP |
170 | } |
171 | ||
172 | ||
173 | static unsigned int | |
174 | acpi_cpufreq_get ( | |
175 | unsigned int cpu) | |
176 | { | |
38f05ed0 TG |
177 | struct cpufreq_acpi_req req; |
178 | long ret; | |
4db8699b | 179 | |
38f05ed0 TG |
180 | req.cpu = cpu; |
181 | ret = work_on_cpu(cpu, processor_get_freq, &req); | |
4db8699b | 182 | |
38f05ed0 | 183 | return ret > 0 ? (unsigned int) ret : 0; |
4db8699b VP |
184 | } |
185 | ||
186 | ||
187 | static int | |
188 | acpi_cpufreq_target ( | |
189 | struct cpufreq_policy *policy, | |
9c0ebcf7 | 190 | unsigned int index) |
4db8699b | 191 | { |
38f05ed0 TG |
192 | struct cpufreq_acpi_req req; |
193 | ||
194 | req.cpu = policy->cpu; | |
195 | req.state = index; | |
196 | ||
197 | return work_on_cpu(req.cpu, processor_set_freq, &req); | |
4db8699b VP |
198 | } |
199 | ||
4db8699b VP |
200 | static int |
201 | acpi_cpufreq_cpu_init ( | |
202 | struct cpufreq_policy *policy) | |
203 | { | |
204 | unsigned int i; | |
205 | unsigned int cpu = policy->cpu; | |
206 | struct cpufreq_acpi_io *data; | |
207 | unsigned int result = 0; | |
946c14f8 | 208 | struct cpufreq_frequency_table *freq_table; |
4db8699b | 209 | |
2d06d8c4 | 210 | pr_debug("acpi_cpufreq_cpu_init\n"); |
4db8699b | 211 | |
d5b73cd8 | 212 | data = kzalloc(sizeof(*data), GFP_KERNEL); |
4db8699b VP |
213 | if (!data) |
214 | return (-ENOMEM); | |
215 | ||
4db8699b VP |
216 | acpi_io_data[cpu] = data; |
217 | ||
4db8699b | 218 | result = acpi_processor_register_performance(&data->acpi_data, cpu); |
4db8699b VP |
219 | |
220 | if (result) | |
221 | goto err_free; | |
222 | ||
223 | /* capability check */ | |
224 | if (data->acpi_data.state_count <= 1) { | |
2d06d8c4 | 225 | pr_debug("No P-States\n"); |
4db8699b VP |
226 | result = -ENODEV; |
227 | goto err_unreg; | |
228 | } | |
229 | ||
230 | if ((data->acpi_data.control_register.space_id != | |
231 | ACPI_ADR_SPACE_FIXED_HARDWARE) || | |
232 | (data->acpi_data.status_register.space_id != | |
233 | ACPI_ADR_SPACE_FIXED_HARDWARE)) { | |
2d06d8c4 | 234 | pr_debug("Unsupported address space [%d, %d]\n", |
4db8699b VP |
235 | (u32) (data->acpi_data.control_register.space_id), |
236 | (u32) (data->acpi_data.status_register.space_id)); | |
237 | result = -ENODEV; | |
238 | goto err_unreg; | |
239 | } | |
240 | ||
241 | /* alloc freq_table */ | |
6396bb22 KC |
242 | freq_table = kcalloc(data->acpi_data.state_count + 1, |
243 | sizeof(*freq_table), | |
4db8699b | 244 | GFP_KERNEL); |
946c14f8 | 245 | if (!freq_table) { |
4db8699b VP |
246 | result = -ENOMEM; |
247 | goto err_unreg; | |
248 | } | |
249 | ||
250 | /* detect transition latency */ | |
251 | policy->cpuinfo.transition_latency = 0; | |
252 | for (i=0; i<data->acpi_data.state_count; i++) { | |
253 | if ((data->acpi_data.states[i].transition_latency * 1000) > | |
254 | policy->cpuinfo.transition_latency) { | |
255 | policy->cpuinfo.transition_latency = | |
256 | data->acpi_data.states[i].transition_latency * 1000; | |
257 | } | |
258 | } | |
4db8699b VP |
259 | |
260 | /* table init */ | |
261 | for (i = 0; i <= data->acpi_data.state_count; i++) | |
262 | { | |
4db8699b | 263 | if (i < data->acpi_data.state_count) { |
946c14f8 | 264 | freq_table[i].frequency = |
4db8699b VP |
265 | data->acpi_data.states[i].core_frequency * 1000; |
266 | } else { | |
946c14f8 | 267 | freq_table[i].frequency = CPUFREQ_TABLE_END; |
4db8699b VP |
268 | } |
269 | } | |
270 | ||
b6663622 | 271 | policy->freq_table = freq_table; |
4db8699b VP |
272 | |
273 | /* notify BIOS that we exist */ | |
274 | acpi_processor_notify_smm(THIS_MODULE); | |
275 | ||
1c5864e2 | 276 | pr_info("CPU%u - ACPI performance management activated\n", cpu); |
4db8699b VP |
277 | |
278 | for (i = 0; i < data->acpi_data.state_count; i++) | |
2d06d8c4 | 279 | pr_debug(" %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n", |
4db8699b VP |
280 | (i == data->acpi_data.state?'*':' '), i, |
281 | (u32) data->acpi_data.states[i].core_frequency, | |
282 | (u32) data->acpi_data.states[i].power, | |
283 | (u32) data->acpi_data.states[i].transition_latency, | |
284 | (u32) data->acpi_data.states[i].bus_master_latency, | |
285 | (u32) data->acpi_data.states[i].status, | |
286 | (u32) data->acpi_data.states[i].control); | |
287 | ||
4db8699b VP |
288 | /* the first call to ->target() should result in us actually |
289 | * writing something to the appropriate registers. */ | |
290 | data->resume = 1; | |
291 | ||
292 | return (result); | |
293 | ||
4db8699b | 294 | err_unreg: |
b2f8dc4c | 295 | acpi_processor_unregister_performance(cpu); |
4db8699b VP |
296 | err_free: |
297 | kfree(data); | |
298 | acpi_io_data[cpu] = NULL; | |
299 | ||
300 | return (result); | |
301 | } | |
302 | ||
303 | ||
304 | static int | |
305 | acpi_cpufreq_cpu_exit ( | |
306 | struct cpufreq_policy *policy) | |
307 | { | |
308 | struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu]; | |
309 | ||
2d06d8c4 | 310 | pr_debug("acpi_cpufreq_cpu_exit\n"); |
4db8699b VP |
311 | |
312 | if (data) { | |
4db8699b | 313 | acpi_io_data[policy->cpu] = NULL; |
b2f8dc4c | 314 | acpi_processor_unregister_performance(policy->cpu); |
555f3fe9 | 315 | kfree(policy->freq_table); |
4db8699b VP |
316 | kfree(data); |
317 | } | |
318 | ||
319 | return (0); | |
320 | } | |
321 | ||
322 | ||
4db8699b | 323 | static struct cpufreq_driver acpi_cpufreq_driver = { |
59b2413b | 324 | .verify = cpufreq_generic_frequency_table_verify, |
9c0ebcf7 | 325 | .target_index = acpi_cpufreq_target, |
4db8699b VP |
326 | .get = acpi_cpufreq_get, |
327 | .init = acpi_cpufreq_cpu_init, | |
328 | .exit = acpi_cpufreq_cpu_exit, | |
329 | .name = "acpi-cpufreq", | |
59b2413b | 330 | .attr = cpufreq_generic_attr, |
4db8699b VP |
331 | }; |
332 | ||
333 | ||
334 | static int __init | |
335 | acpi_cpufreq_init (void) | |
336 | { | |
2d06d8c4 | 337 | pr_debug("acpi_cpufreq_init\n"); |
4db8699b VP |
338 | |
339 | return cpufreq_register_driver(&acpi_cpufreq_driver); | |
340 | } | |
341 | ||
342 | ||
343 | static void __exit | |
344 | acpi_cpufreq_exit (void) | |
345 | { | |
2d06d8c4 | 346 | pr_debug("acpi_cpufreq_exit\n"); |
4db8699b VP |
347 | |
348 | cpufreq_unregister_driver(&acpi_cpufreq_driver); | |
4db8699b VP |
349 | } |
350 | ||
4db8699b VP |
351 | late_initcall(acpi_cpufreq_init); |
352 | module_exit(acpi_cpufreq_exit); |