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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
4db8699b | 2 | /* |
4db8699b VP |
3 | * This file provides the ACPI based P-state support. This |
4 | * module works with generic cpufreq infrastructure. Most of | |
5 | * the code is based on i386 version | |
6 | * (arch/i386/kernel/cpu/cpufreq/acpi-cpufreq.c) | |
7 | * | |
8 | * Copyright (C) 2005 Intel Corp | |
9 | * Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> | |
10 | */ | |
11 | ||
1c5864e2 JP |
12 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
13 | ||
4db8699b | 14 | #include <linux/kernel.h> |
5a0e3ad6 | 15 | #include <linux/slab.h> |
4db8699b VP |
16 | #include <linux/module.h> |
17 | #include <linux/init.h> | |
18 | #include <linux/cpufreq.h> | |
19 | #include <linux/proc_fs.h> | |
4db8699b | 20 | #include <asm/io.h> |
7c0f6ba6 | 21 | #include <linux/uaccess.h> |
4db8699b VP |
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 | ||
4db8699b VP |
31 | struct cpufreq_acpi_io { |
32 | struct acpi_processor_performance acpi_data; | |
4db8699b VP |
33 | unsigned int resume; |
34 | }; | |
35 | ||
38f05ed0 TG |
36 | struct cpufreq_acpi_req { |
37 | unsigned int cpu; | |
38 | unsigned int state; | |
39 | }; | |
40 | ||
4db8699b VP |
41 | static struct cpufreq_acpi_io *acpi_io_data[NR_CPUS]; |
42 | ||
43 | static struct cpufreq_driver acpi_cpufreq_driver; | |
44 | ||
45 | ||
46 | static int | |
47 | processor_set_pstate ( | |
48 | u32 value) | |
49 | { | |
50 | s64 retval; | |
51 | ||
2d06d8c4 | 52 | pr_debug("processor_set_pstate\n"); |
4db8699b VP |
53 | |
54 | retval = ia64_pal_set_pstate((u64)value); | |
55 | ||
56 | if (retval) { | |
4c56f573 | 57 | pr_debug("Failed to set freq to 0x%x, with error 0x%llx\n", |
4db8699b VP |
58 | value, retval); |
59 | return -ENODEV; | |
60 | } | |
61 | return (int)retval; | |
62 | } | |
63 | ||
64 | ||
65 | static int | |
66 | processor_get_pstate ( | |
67 | u32 *value) | |
68 | { | |
69 | u64 pstate_index = 0; | |
70 | s64 retval; | |
71 | ||
2d06d8c4 | 72 | pr_debug("processor_get_pstate\n"); |
4db8699b | 73 | |
17e77b1c VP |
74 | retval = ia64_pal_get_pstate(&pstate_index, |
75 | PAL_GET_PSTATE_TYPE_INSTANT); | |
4db8699b VP |
76 | *value = (u32) pstate_index; |
77 | ||
78 | if (retval) | |
2d06d8c4 | 79 | pr_debug("Failed to get current freq with " |
4c56f573 | 80 | "error 0x%llx, idx 0x%x\n", retval, *value); |
4db8699b VP |
81 | |
82 | return (int)retval; | |
83 | } | |
84 | ||
85 | ||
86 | /* To be used only after data->acpi_data is initialized */ | |
87 | static unsigned | |
88 | extract_clock ( | |
89 | struct cpufreq_acpi_io *data, | |
38f05ed0 | 90 | unsigned value) |
4db8699b VP |
91 | { |
92 | unsigned long i; | |
93 | ||
2d06d8c4 | 94 | pr_debug("extract_clock\n"); |
4db8699b VP |
95 | |
96 | for (i = 0; i < data->acpi_data.state_count; i++) { | |
17e77b1c | 97 | if (value == data->acpi_data.states[i].status) |
4db8699b VP |
98 | return data->acpi_data.states[i].core_frequency; |
99 | } | |
100 | return data->acpi_data.states[i-1].core_frequency; | |
101 | } | |
102 | ||
103 | ||
38f05ed0 | 104 | static long |
4db8699b | 105 | processor_get_freq ( |
38f05ed0 | 106 | void *arg) |
4db8699b | 107 | { |
38f05ed0 TG |
108 | struct cpufreq_acpi_req *req = arg; |
109 | unsigned int cpu = req->cpu; | |
110 | struct cpufreq_acpi_io *data = acpi_io_data[cpu]; | |
111 | u32 value; | |
112 | int ret; | |
4db8699b | 113 | |
2d06d8c4 | 114 | pr_debug("processor_get_freq\n"); |
182fdd22 | 115 | if (smp_processor_id() != cpu) |
38f05ed0 | 116 | return -EAGAIN; |
4db8699b | 117 | |
17e77b1c | 118 | /* processor_get_pstate gets the instantaneous frequency */ |
4db8699b | 119 | ret = processor_get_pstate(&value); |
4db8699b | 120 | if (ret) { |
b49c22a6 | 121 | pr_warn("get performance failed with error %d\n", ret); |
38f05ed0 | 122 | return ret; |
4db8699b | 123 | } |
38f05ed0 | 124 | return 1000 * extract_clock(data, value); |
4db8699b VP |
125 | } |
126 | ||
127 | ||
38f05ed0 | 128 | static long |
4db8699b | 129 | processor_set_freq ( |
38f05ed0 | 130 | void *arg) |
4db8699b | 131 | { |
38f05ed0 TG |
132 | struct cpufreq_acpi_req *req = arg; |
133 | unsigned int cpu = req->cpu; | |
134 | struct cpufreq_acpi_io *data = acpi_io_data[cpu]; | |
135 | int ret, state = req->state; | |
136 | u32 value; | |
4db8699b | 137 | |
2d06d8c4 | 138 | pr_debug("processor_set_freq\n"); |
38f05ed0 TG |
139 | if (smp_processor_id() != cpu) |
140 | return -EAGAIN; | |
4db8699b VP |
141 | |
142 | if (state == data->acpi_data.state) { | |
143 | if (unlikely(data->resume)) { | |
2d06d8c4 | 144 | pr_debug("Called after resume, resetting to P%d\n", state); |
4db8699b VP |
145 | data->resume = 0; |
146 | } else { | |
2d06d8c4 | 147 | pr_debug("Already at target state (P%d)\n", state); |
38f05ed0 | 148 | return 0; |
4db8699b VP |
149 | } |
150 | } | |
151 | ||
2d06d8c4 | 152 | pr_debug("Transitioning from P%d to P%d\n", |
4db8699b VP |
153 | data->acpi_data.state, state); |
154 | ||
4db8699b VP |
155 | /* |
156 | * First we write the target state's 'control' value to the | |
157 | * control_register. | |
158 | */ | |
4db8699b VP |
159 | value = (u32) data->acpi_data.states[state].control; |
160 | ||
2d06d8c4 | 161 | pr_debug("Transitioning to state: 0x%08x\n", value); |
4db8699b VP |
162 | |
163 | ret = processor_set_pstate(value); | |
164 | if (ret) { | |
b49c22a6 | 165 | pr_warn("Transition failed with error %d\n", ret); |
38f05ed0 | 166 | return -ENODEV; |
4db8699b VP |
167 | } |
168 | ||
4db8699b | 169 | data->acpi_data.state = state; |
38f05ed0 | 170 | return 0; |
4db8699b VP |
171 | } |
172 | ||
173 | ||
174 | static unsigned int | |
175 | acpi_cpufreq_get ( | |
176 | unsigned int cpu) | |
177 | { | |
38f05ed0 TG |
178 | struct cpufreq_acpi_req req; |
179 | long ret; | |
4db8699b | 180 | |
38f05ed0 TG |
181 | req.cpu = cpu; |
182 | ret = work_on_cpu(cpu, processor_get_freq, &req); | |
4db8699b | 183 | |
38f05ed0 | 184 | return ret > 0 ? (unsigned int) ret : 0; |
4db8699b VP |
185 | } |
186 | ||
187 | ||
188 | static int | |
189 | acpi_cpufreq_target ( | |
190 | struct cpufreq_policy *policy, | |
9c0ebcf7 | 191 | unsigned int index) |
4db8699b | 192 | { |
38f05ed0 TG |
193 | struct cpufreq_acpi_req req; |
194 | ||
195 | req.cpu = policy->cpu; | |
196 | req.state = index; | |
197 | ||
198 | return work_on_cpu(req.cpu, processor_set_freq, &req); | |
4db8699b VP |
199 | } |
200 | ||
4db8699b VP |
201 | static int |
202 | acpi_cpufreq_cpu_init ( | |
203 | struct cpufreq_policy *policy) | |
204 | { | |
205 | unsigned int i; | |
206 | unsigned int cpu = policy->cpu; | |
207 | struct cpufreq_acpi_io *data; | |
208 | unsigned int result = 0; | |
946c14f8 | 209 | struct cpufreq_frequency_table *freq_table; |
4db8699b | 210 | |
2d06d8c4 | 211 | pr_debug("acpi_cpufreq_cpu_init\n"); |
4db8699b | 212 | |
d5b73cd8 | 213 | data = kzalloc(sizeof(*data), GFP_KERNEL); |
4db8699b VP |
214 | if (!data) |
215 | return (-ENOMEM); | |
216 | ||
4db8699b VP |
217 | acpi_io_data[cpu] = data; |
218 | ||
4db8699b | 219 | result = acpi_processor_register_performance(&data->acpi_data, cpu); |
4db8699b VP |
220 | |
221 | if (result) | |
222 | goto err_free; | |
223 | ||
224 | /* capability check */ | |
225 | if (data->acpi_data.state_count <= 1) { | |
2d06d8c4 | 226 | pr_debug("No P-States\n"); |
4db8699b VP |
227 | result = -ENODEV; |
228 | goto err_unreg; | |
229 | } | |
230 | ||
231 | if ((data->acpi_data.control_register.space_id != | |
232 | ACPI_ADR_SPACE_FIXED_HARDWARE) || | |
233 | (data->acpi_data.status_register.space_id != | |
234 | ACPI_ADR_SPACE_FIXED_HARDWARE)) { | |
2d06d8c4 | 235 | pr_debug("Unsupported address space [%d, %d]\n", |
4db8699b VP |
236 | (u32) (data->acpi_data.control_register.space_id), |
237 | (u32) (data->acpi_data.status_register.space_id)); | |
238 | result = -ENODEV; | |
239 | goto err_unreg; | |
240 | } | |
241 | ||
242 | /* alloc freq_table */ | |
6396bb22 KC |
243 | freq_table = kcalloc(data->acpi_data.state_count + 1, |
244 | sizeof(*freq_table), | |
4db8699b | 245 | GFP_KERNEL); |
946c14f8 | 246 | if (!freq_table) { |
4db8699b VP |
247 | result = -ENOMEM; |
248 | goto err_unreg; | |
249 | } | |
250 | ||
251 | /* detect transition latency */ | |
252 | policy->cpuinfo.transition_latency = 0; | |
253 | for (i=0; i<data->acpi_data.state_count; i++) { | |
254 | if ((data->acpi_data.states[i].transition_latency * 1000) > | |
255 | policy->cpuinfo.transition_latency) { | |
256 | policy->cpuinfo.transition_latency = | |
257 | data->acpi_data.states[i].transition_latency * 1000; | |
258 | } | |
259 | } | |
4db8699b VP |
260 | |
261 | /* table init */ | |
262 | for (i = 0; i <= data->acpi_data.state_count; i++) | |
263 | { | |
4db8699b | 264 | if (i < data->acpi_data.state_count) { |
946c14f8 | 265 | freq_table[i].frequency = |
4db8699b VP |
266 | data->acpi_data.states[i].core_frequency * 1000; |
267 | } else { | |
946c14f8 | 268 | freq_table[i].frequency = CPUFREQ_TABLE_END; |
4db8699b VP |
269 | } |
270 | } | |
271 | ||
b6663622 | 272 | policy->freq_table = freq_table; |
4db8699b VP |
273 | |
274 | /* notify BIOS that we exist */ | |
275 | acpi_processor_notify_smm(THIS_MODULE); | |
276 | ||
1c5864e2 | 277 | pr_info("CPU%u - ACPI performance management activated\n", cpu); |
4db8699b VP |
278 | |
279 | for (i = 0; i < data->acpi_data.state_count; i++) | |
2d06d8c4 | 280 | pr_debug(" %cP%d: %d MHz, %d mW, %d uS, %d uS, 0x%x 0x%x\n", |
4db8699b VP |
281 | (i == data->acpi_data.state?'*':' '), i, |
282 | (u32) data->acpi_data.states[i].core_frequency, | |
283 | (u32) data->acpi_data.states[i].power, | |
284 | (u32) data->acpi_data.states[i].transition_latency, | |
285 | (u32) data->acpi_data.states[i].bus_master_latency, | |
286 | (u32) data->acpi_data.states[i].status, | |
287 | (u32) data->acpi_data.states[i].control); | |
288 | ||
4db8699b VP |
289 | /* the first call to ->target() should result in us actually |
290 | * writing something to the appropriate registers. */ | |
291 | data->resume = 1; | |
292 | ||
293 | return (result); | |
294 | ||
4db8699b | 295 | err_unreg: |
b2f8dc4c | 296 | acpi_processor_unregister_performance(cpu); |
4db8699b VP |
297 | err_free: |
298 | kfree(data); | |
299 | acpi_io_data[cpu] = NULL; | |
300 | ||
301 | return (result); | |
302 | } | |
303 | ||
304 | ||
305 | static int | |
306 | acpi_cpufreq_cpu_exit ( | |
307 | struct cpufreq_policy *policy) | |
308 | { | |
309 | struct cpufreq_acpi_io *data = acpi_io_data[policy->cpu]; | |
310 | ||
2d06d8c4 | 311 | pr_debug("acpi_cpufreq_cpu_exit\n"); |
4db8699b VP |
312 | |
313 | if (data) { | |
4db8699b | 314 | acpi_io_data[policy->cpu] = NULL; |
b2f8dc4c | 315 | acpi_processor_unregister_performance(policy->cpu); |
555f3fe9 | 316 | kfree(policy->freq_table); |
4db8699b VP |
317 | kfree(data); |
318 | } | |
319 | ||
320 | return (0); | |
321 | } | |
322 | ||
323 | ||
4db8699b | 324 | static struct cpufreq_driver acpi_cpufreq_driver = { |
59b2413b | 325 | .verify = cpufreq_generic_frequency_table_verify, |
9c0ebcf7 | 326 | .target_index = acpi_cpufreq_target, |
4db8699b VP |
327 | .get = acpi_cpufreq_get, |
328 | .init = acpi_cpufreq_cpu_init, | |
329 | .exit = acpi_cpufreq_cpu_exit, | |
330 | .name = "acpi-cpufreq", | |
59b2413b | 331 | .attr = cpufreq_generic_attr, |
4db8699b VP |
332 | }; |
333 | ||
334 | ||
335 | static int __init | |
336 | acpi_cpufreq_init (void) | |
337 | { | |
2d06d8c4 | 338 | pr_debug("acpi_cpufreq_init\n"); |
4db8699b VP |
339 | |
340 | return cpufreq_register_driver(&acpi_cpufreq_driver); | |
341 | } | |
342 | ||
343 | ||
344 | static void __exit | |
345 | acpi_cpufreq_exit (void) | |
346 | { | |
2d06d8c4 | 347 | pr_debug("acpi_cpufreq_exit\n"); |
4db8699b VP |
348 | |
349 | cpufreq_unregister_driver(&acpi_cpufreq_driver); | |
4db8699b VP |
350 | } |
351 | ||
4db8699b VP |
352 | late_initcall(acpi_cpufreq_init); |
353 | module_exit(acpi_cpufreq_exit); |