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b3d627a5 VS |
1 | /* |
2 | * POWERNV cpufreq driver for the IBM POWER processors | |
3 | * | |
4 | * (C) Copyright IBM 2014 | |
5 | * | |
6 | * Author: Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com> | |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2, or (at your option) | |
11 | * any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | */ | |
19 | ||
20 | #define pr_fmt(fmt) "powernv-cpufreq: " fmt | |
21 | ||
22 | #include <linux/kernel.h> | |
23 | #include <linux/sysfs.h> | |
24 | #include <linux/cpumask.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/cpufreq.h> | |
27 | #include <linux/smp.h> | |
28 | #include <linux/of.h> | |
cf30af76 | 29 | #include <linux/reboot.h> |
053819e0 | 30 | #include <linux/slab.h> |
b3d627a5 VS |
31 | |
32 | #include <asm/cputhreads.h> | |
6174bac8 | 33 | #include <asm/firmware.h> |
b3d627a5 | 34 | #include <asm/reg.h> |
f3cae355 | 35 | #include <asm/smp.h> /* Required for cpu_sibling_mask() in UP configs */ |
cb166fa9 | 36 | #include <asm/opal.h> |
b3d627a5 VS |
37 | |
38 | #define POWERNV_MAX_PSTATES 256 | |
09a972d1 SB |
39 | #define PMSR_PSAFE_ENABLE (1UL << 30) |
40 | #define PMSR_SPR_EM_DISABLE (1UL << 31) | |
41 | #define PMSR_MAX(x) ((x >> 32) & 0xFF) | |
b3d627a5 VS |
42 | |
43 | static struct cpufreq_frequency_table powernv_freqs[POWERNV_MAX_PSTATES+1]; | |
cb166fa9 | 44 | static bool rebooting, throttled, occ_reset; |
b3d627a5 | 45 | |
053819e0 SB |
46 | static struct chip { |
47 | unsigned int id; | |
48 | bool throttled; | |
735366fc SB |
49 | cpumask_t mask; |
50 | struct work_struct throttle; | |
053819e0 SB |
51 | } *chips; |
52 | ||
53 | static int nr_chips; | |
54 | ||
b3d627a5 VS |
55 | /* |
56 | * Note: The set of pstates consists of contiguous integers, the | |
57 | * smallest of which is indicated by powernv_pstate_info.min, the | |
58 | * largest of which is indicated by powernv_pstate_info.max. | |
59 | * | |
60 | * The nominal pstate is the highest non-turbo pstate in this | |
61 | * platform. This is indicated by powernv_pstate_info.nominal. | |
62 | */ | |
63 | static struct powernv_pstate_info { | |
64 | int min; | |
65 | int max; | |
66 | int nominal; | |
67 | int nr_pstates; | |
68 | } powernv_pstate_info; | |
69 | ||
70 | /* | |
71 | * Initialize the freq table based on data obtained | |
72 | * from the firmware passed via device-tree | |
73 | */ | |
74 | static int init_powernv_pstates(void) | |
75 | { | |
76 | struct device_node *power_mgt; | |
77 | int i, pstate_min, pstate_max, pstate_nominal, nr_pstates = 0; | |
78 | const __be32 *pstate_ids, *pstate_freqs; | |
79 | u32 len_ids, len_freqs; | |
80 | ||
81 | power_mgt = of_find_node_by_path("/ibm,opal/power-mgt"); | |
82 | if (!power_mgt) { | |
83 | pr_warn("power-mgt node not found\n"); | |
84 | return -ENODEV; | |
85 | } | |
86 | ||
87 | if (of_property_read_u32(power_mgt, "ibm,pstate-min", &pstate_min)) { | |
88 | pr_warn("ibm,pstate-min node not found\n"); | |
89 | return -ENODEV; | |
90 | } | |
91 | ||
92 | if (of_property_read_u32(power_mgt, "ibm,pstate-max", &pstate_max)) { | |
93 | pr_warn("ibm,pstate-max node not found\n"); | |
94 | return -ENODEV; | |
95 | } | |
96 | ||
97 | if (of_property_read_u32(power_mgt, "ibm,pstate-nominal", | |
98 | &pstate_nominal)) { | |
99 | pr_warn("ibm,pstate-nominal not found\n"); | |
100 | return -ENODEV; | |
101 | } | |
102 | pr_info("cpufreq pstate min %d nominal %d max %d\n", pstate_min, | |
103 | pstate_nominal, pstate_max); | |
104 | ||
105 | pstate_ids = of_get_property(power_mgt, "ibm,pstate-ids", &len_ids); | |
106 | if (!pstate_ids) { | |
107 | pr_warn("ibm,pstate-ids not found\n"); | |
108 | return -ENODEV; | |
109 | } | |
110 | ||
111 | pstate_freqs = of_get_property(power_mgt, "ibm,pstate-frequencies-mhz", | |
112 | &len_freqs); | |
113 | if (!pstate_freqs) { | |
114 | pr_warn("ibm,pstate-frequencies-mhz not found\n"); | |
115 | return -ENODEV; | |
116 | } | |
117 | ||
6174bac8 VS |
118 | if (len_ids != len_freqs) { |
119 | pr_warn("Entries in ibm,pstate-ids and " | |
120 | "ibm,pstate-frequencies-mhz does not match\n"); | |
121 | } | |
122 | ||
b3d627a5 VS |
123 | nr_pstates = min(len_ids, len_freqs) / sizeof(u32); |
124 | if (!nr_pstates) { | |
125 | pr_warn("No PStates found\n"); | |
126 | return -ENODEV; | |
127 | } | |
128 | ||
129 | pr_debug("NR PStates %d\n", nr_pstates); | |
130 | for (i = 0; i < nr_pstates; i++) { | |
131 | u32 id = be32_to_cpu(pstate_ids[i]); | |
132 | u32 freq = be32_to_cpu(pstate_freqs[i]); | |
133 | ||
134 | pr_debug("PState id %d freq %d MHz\n", id, freq); | |
135 | powernv_freqs[i].frequency = freq * 1000; /* kHz */ | |
0692c691 | 136 | powernv_freqs[i].driver_data = id; |
b3d627a5 VS |
137 | } |
138 | /* End of list marker entry */ | |
139 | powernv_freqs[i].frequency = CPUFREQ_TABLE_END; | |
140 | ||
141 | powernv_pstate_info.min = pstate_min; | |
142 | powernv_pstate_info.max = pstate_max; | |
143 | powernv_pstate_info.nominal = pstate_nominal; | |
144 | powernv_pstate_info.nr_pstates = nr_pstates; | |
145 | ||
146 | return 0; | |
147 | } | |
148 | ||
149 | /* Returns the CPU frequency corresponding to the pstate_id. */ | |
150 | static unsigned int pstate_id_to_freq(int pstate_id) | |
151 | { | |
152 | int i; | |
153 | ||
154 | i = powernv_pstate_info.max - pstate_id; | |
6174bac8 VS |
155 | if (i >= powernv_pstate_info.nr_pstates || i < 0) { |
156 | pr_warn("PState id %d outside of PState table, " | |
157 | "reporting nominal id %d instead\n", | |
158 | pstate_id, powernv_pstate_info.nominal); | |
159 | i = powernv_pstate_info.max - powernv_pstate_info.nominal; | |
160 | } | |
b3d627a5 VS |
161 | |
162 | return powernv_freqs[i].frequency; | |
163 | } | |
164 | ||
165 | /* | |
166 | * cpuinfo_nominal_freq_show - Show the nominal CPU frequency as indicated by | |
167 | * the firmware | |
168 | */ | |
169 | static ssize_t cpuinfo_nominal_freq_show(struct cpufreq_policy *policy, | |
170 | char *buf) | |
171 | { | |
172 | return sprintf(buf, "%u\n", | |
173 | pstate_id_to_freq(powernv_pstate_info.nominal)); | |
174 | } | |
175 | ||
176 | struct freq_attr cpufreq_freq_attr_cpuinfo_nominal_freq = | |
177 | __ATTR_RO(cpuinfo_nominal_freq); | |
178 | ||
179 | static struct freq_attr *powernv_cpu_freq_attr[] = { | |
180 | &cpufreq_freq_attr_scaling_available_freqs, | |
181 | &cpufreq_freq_attr_cpuinfo_nominal_freq, | |
182 | NULL, | |
183 | }; | |
184 | ||
185 | /* Helper routines */ | |
186 | ||
187 | /* Access helpers to power mgt SPR */ | |
188 | ||
189 | static inline unsigned long get_pmspr(unsigned long sprn) | |
190 | { | |
191 | switch (sprn) { | |
192 | case SPRN_PMCR: | |
193 | return mfspr(SPRN_PMCR); | |
194 | ||
195 | case SPRN_PMICR: | |
196 | return mfspr(SPRN_PMICR); | |
197 | ||
198 | case SPRN_PMSR: | |
199 | return mfspr(SPRN_PMSR); | |
200 | } | |
201 | BUG(); | |
202 | } | |
203 | ||
204 | static inline void set_pmspr(unsigned long sprn, unsigned long val) | |
205 | { | |
206 | switch (sprn) { | |
207 | case SPRN_PMCR: | |
208 | mtspr(SPRN_PMCR, val); | |
209 | return; | |
210 | ||
211 | case SPRN_PMICR: | |
212 | mtspr(SPRN_PMICR, val); | |
213 | return; | |
214 | } | |
215 | BUG(); | |
216 | } | |
217 | ||
218 | /* | |
219 | * Use objects of this type to query/update | |
220 | * pstates on a remote CPU via smp_call_function. | |
221 | */ | |
222 | struct powernv_smp_call_data { | |
223 | unsigned int freq; | |
224 | int pstate_id; | |
225 | }; | |
226 | ||
227 | /* | |
228 | * powernv_read_cpu_freq: Reads the current frequency on this CPU. | |
229 | * | |
230 | * Called via smp_call_function. | |
231 | * | |
232 | * Note: The caller of the smp_call_function should pass an argument of | |
233 | * the type 'struct powernv_smp_call_data *' along with this function. | |
234 | * | |
235 | * The current frequency on this CPU will be returned via | |
236 | * ((struct powernv_smp_call_data *)arg)->freq; | |
237 | */ | |
238 | static void powernv_read_cpu_freq(void *arg) | |
239 | { | |
240 | unsigned long pmspr_val; | |
241 | s8 local_pstate_id; | |
242 | struct powernv_smp_call_data *freq_data = arg; | |
243 | ||
244 | pmspr_val = get_pmspr(SPRN_PMSR); | |
245 | ||
246 | /* | |
247 | * The local pstate id corresponds bits 48..55 in the PMSR. | |
248 | * Note: Watch out for the sign! | |
249 | */ | |
250 | local_pstate_id = (pmspr_val >> 48) & 0xFF; | |
251 | freq_data->pstate_id = local_pstate_id; | |
252 | freq_data->freq = pstate_id_to_freq(freq_data->pstate_id); | |
253 | ||
254 | pr_debug("cpu %d pmsr %016lX pstate_id %d frequency %d kHz\n", | |
255 | raw_smp_processor_id(), pmspr_val, freq_data->pstate_id, | |
256 | freq_data->freq); | |
257 | } | |
258 | ||
259 | /* | |
260 | * powernv_cpufreq_get: Returns the CPU frequency as reported by the | |
261 | * firmware for CPU 'cpu'. This value is reported through the sysfs | |
262 | * file cpuinfo_cur_freq. | |
263 | */ | |
60d1ea4e | 264 | static unsigned int powernv_cpufreq_get(unsigned int cpu) |
b3d627a5 VS |
265 | { |
266 | struct powernv_smp_call_data freq_data; | |
267 | ||
268 | smp_call_function_any(cpu_sibling_mask(cpu), powernv_read_cpu_freq, | |
269 | &freq_data, 1); | |
270 | ||
271 | return freq_data.freq; | |
272 | } | |
273 | ||
274 | /* | |
275 | * set_pstate: Sets the pstate on this CPU. | |
276 | * | |
277 | * This is called via an smp_call_function. | |
278 | * | |
279 | * The caller must ensure that freq_data is of the type | |
280 | * (struct powernv_smp_call_data *) and the pstate_id which needs to be set | |
281 | * on this CPU should be present in freq_data->pstate_id. | |
282 | */ | |
283 | static void set_pstate(void *freq_data) | |
284 | { | |
285 | unsigned long val; | |
286 | unsigned long pstate_ul = | |
287 | ((struct powernv_smp_call_data *) freq_data)->pstate_id; | |
288 | ||
289 | val = get_pmspr(SPRN_PMCR); | |
290 | val = val & 0x0000FFFFFFFFFFFFULL; | |
291 | ||
292 | pstate_ul = pstate_ul & 0xFF; | |
293 | ||
294 | /* Set both global(bits 56..63) and local(bits 48..55) PStates */ | |
295 | val = val | (pstate_ul << 56) | (pstate_ul << 48); | |
296 | ||
297 | pr_debug("Setting cpu %d pmcr to %016lX\n", | |
298 | raw_smp_processor_id(), val); | |
299 | set_pmspr(SPRN_PMCR, val); | |
300 | } | |
301 | ||
cf30af76 SB |
302 | /* |
303 | * get_nominal_index: Returns the index corresponding to the nominal | |
304 | * pstate in the cpufreq table | |
305 | */ | |
306 | static inline unsigned int get_nominal_index(void) | |
307 | { | |
308 | return powernv_pstate_info.max - powernv_pstate_info.nominal; | |
309 | } | |
310 | ||
735366fc | 311 | static void powernv_cpufreq_throttle_check(void *data) |
09a972d1 | 312 | { |
735366fc | 313 | unsigned int cpu = smp_processor_id(); |
09a972d1 | 314 | unsigned long pmsr; |
3dd3ebe5 | 315 | int pmsr_pmax, i; |
09a972d1 SB |
316 | |
317 | pmsr = get_pmspr(SPRN_PMSR); | |
318 | ||
053819e0 SB |
319 | for (i = 0; i < nr_chips; i++) |
320 | if (chips[i].id == cpu_to_chip_id(cpu)) | |
321 | break; | |
322 | ||
09a972d1 SB |
323 | /* Check for Pmax Capping */ |
324 | pmsr_pmax = (s8)PMSR_MAX(pmsr); | |
325 | if (pmsr_pmax != powernv_pstate_info.max) { | |
053819e0 SB |
326 | if (chips[i].throttled) |
327 | goto next; | |
328 | chips[i].throttled = true; | |
329 | pr_info("CPU %d on Chip %u has Pmax reduced to %d\n", cpu, | |
330 | chips[i].id, pmsr_pmax); | |
331 | } else if (chips[i].throttled) { | |
332 | chips[i].throttled = false; | |
333 | pr_info("CPU %d on Chip %u has Pmax restored to %d\n", cpu, | |
334 | chips[i].id, pmsr_pmax); | |
09a972d1 SB |
335 | } |
336 | ||
3dd3ebe5 | 337 | /* Check if Psafe_mode_active is set in PMSR. */ |
053819e0 | 338 | next: |
3dd3ebe5 | 339 | if (pmsr & PMSR_PSAFE_ENABLE) { |
09a972d1 SB |
340 | throttled = true; |
341 | pr_info("Pstate set to safe frequency\n"); | |
342 | } | |
343 | ||
344 | /* Check if SPR_EM_DISABLE is set in PMSR */ | |
345 | if (pmsr & PMSR_SPR_EM_DISABLE) { | |
346 | throttled = true; | |
347 | pr_info("Frequency Control disabled from OS\n"); | |
348 | } | |
349 | ||
350 | if (throttled) { | |
351 | pr_info("PMSR = %16lx\n", pmsr); | |
352 | pr_crit("CPU Frequency could be throttled\n"); | |
353 | } | |
354 | } | |
355 | ||
b3d627a5 VS |
356 | /* |
357 | * powernv_cpufreq_target_index: Sets the frequency corresponding to | |
358 | * the cpufreq table entry indexed by new_index on the cpus in the | |
359 | * mask policy->cpus | |
360 | */ | |
361 | static int powernv_cpufreq_target_index(struct cpufreq_policy *policy, | |
362 | unsigned int new_index) | |
363 | { | |
364 | struct powernv_smp_call_data freq_data; | |
365 | ||
cf30af76 SB |
366 | if (unlikely(rebooting) && new_index != get_nominal_index()) |
367 | return 0; | |
368 | ||
09a972d1 | 369 | if (!throttled) |
735366fc | 370 | powernv_cpufreq_throttle_check(NULL); |
09a972d1 | 371 | |
0692c691 | 372 | freq_data.pstate_id = powernv_freqs[new_index].driver_data; |
b3d627a5 VS |
373 | |
374 | /* | |
375 | * Use smp_call_function to send IPI and execute the | |
376 | * mtspr on target CPU. We could do that without IPI | |
377 | * if current CPU is within policy->cpus (core) | |
378 | */ | |
379 | smp_call_function_any(policy->cpus, set_pstate, &freq_data, 1); | |
380 | ||
381 | return 0; | |
382 | } | |
383 | ||
384 | static int powernv_cpufreq_cpu_init(struct cpufreq_policy *policy) | |
385 | { | |
386 | int base, i; | |
387 | ||
388 | base = cpu_first_thread_sibling(policy->cpu); | |
389 | ||
390 | for (i = 0; i < threads_per_core; i++) | |
391 | cpumask_set_cpu(base + i, policy->cpus); | |
392 | ||
393 | return cpufreq_table_validate_and_show(policy, powernv_freqs); | |
394 | } | |
395 | ||
cf30af76 SB |
396 | static int powernv_cpufreq_reboot_notifier(struct notifier_block *nb, |
397 | unsigned long action, void *unused) | |
398 | { | |
399 | int cpu; | |
400 | struct cpufreq_policy cpu_policy; | |
401 | ||
402 | rebooting = true; | |
403 | for_each_online_cpu(cpu) { | |
404 | cpufreq_get_policy(&cpu_policy, cpu); | |
405 | powernv_cpufreq_target_index(&cpu_policy, get_nominal_index()); | |
406 | } | |
407 | ||
408 | return NOTIFY_DONE; | |
409 | } | |
410 | ||
411 | static struct notifier_block powernv_cpufreq_reboot_nb = { | |
412 | .notifier_call = powernv_cpufreq_reboot_notifier, | |
413 | }; | |
414 | ||
735366fc SB |
415 | void powernv_cpufreq_work_fn(struct work_struct *work) |
416 | { | |
417 | struct chip *chip = container_of(work, struct chip, throttle); | |
418 | ||
419 | smp_call_function_any(&chip->mask, | |
420 | powernv_cpufreq_throttle_check, NULL, 0); | |
421 | } | |
422 | ||
cb166fa9 SB |
423 | static char throttle_reason[][30] = { |
424 | "No throttling", | |
425 | "Power Cap", | |
426 | "Processor Over Temperature", | |
427 | "Power Supply Failure", | |
428 | "Over Current", | |
429 | "OCC Reset" | |
430 | }; | |
431 | ||
432 | static int powernv_cpufreq_occ_msg(struct notifier_block *nb, | |
433 | unsigned long msg_type, void *_msg) | |
434 | { | |
435 | struct opal_msg *msg = _msg; | |
436 | struct opal_occ_msg omsg; | |
735366fc | 437 | int i; |
cb166fa9 SB |
438 | |
439 | if (msg_type != OPAL_MSG_OCC) | |
440 | return 0; | |
441 | ||
442 | omsg.type = be64_to_cpu(msg->params[0]); | |
443 | ||
444 | switch (omsg.type) { | |
445 | case OCC_RESET: | |
446 | occ_reset = true; | |
447 | /* | |
448 | * powernv_cpufreq_throttle_check() is called in | |
449 | * target() callback which can detect the throttle state | |
450 | * for governors like ondemand. | |
451 | * But static governors will not call target() often thus | |
452 | * report throttling here. | |
453 | */ | |
454 | if (!throttled) { | |
455 | throttled = true; | |
456 | pr_crit("CPU Frequency is throttled\n"); | |
457 | } | |
458 | pr_info("OCC: Reset\n"); | |
459 | break; | |
460 | case OCC_LOAD: | |
461 | pr_info("OCC: Loaded\n"); | |
462 | break; | |
463 | case OCC_THROTTLE: | |
464 | omsg.chip = be64_to_cpu(msg->params[1]); | |
465 | omsg.throttle_status = be64_to_cpu(msg->params[2]); | |
466 | ||
467 | if (occ_reset) { | |
468 | occ_reset = false; | |
469 | throttled = false; | |
470 | pr_info("OCC: Active\n"); | |
735366fc SB |
471 | |
472 | for (i = 0; i < nr_chips; i++) | |
473 | schedule_work(&chips[i].throttle); | |
474 | ||
cb166fa9 SB |
475 | return 0; |
476 | } | |
477 | ||
478 | if (omsg.throttle_status && | |
479 | omsg.throttle_status <= OCC_MAX_THROTTLE_STATUS) | |
480 | pr_info("OCC: Chip %u Pmax reduced due to %s\n", | |
481 | (unsigned int)omsg.chip, | |
482 | throttle_reason[omsg.throttle_status]); | |
483 | else if (!omsg.throttle_status) | |
484 | pr_info("OCC: Chip %u %s\n", (unsigned int)omsg.chip, | |
485 | throttle_reason[omsg.throttle_status]); | |
735366fc SB |
486 | else |
487 | return 0; | |
488 | ||
489 | for (i = 0; i < nr_chips; i++) | |
490 | if (chips[i].id == omsg.chip) | |
491 | schedule_work(&chips[i].throttle); | |
cb166fa9 SB |
492 | } |
493 | return 0; | |
494 | } | |
495 | ||
496 | static struct notifier_block powernv_cpufreq_opal_nb = { | |
497 | .notifier_call = powernv_cpufreq_occ_msg, | |
498 | .next = NULL, | |
499 | .priority = 0, | |
500 | }; | |
501 | ||
b120339c PM |
502 | static void powernv_cpufreq_stop_cpu(struct cpufreq_policy *policy) |
503 | { | |
504 | struct powernv_smp_call_data freq_data; | |
505 | ||
506 | freq_data.pstate_id = powernv_pstate_info.min; | |
507 | smp_call_function_single(policy->cpu, set_pstate, &freq_data, 1); | |
508 | } | |
509 | ||
b3d627a5 VS |
510 | static struct cpufreq_driver powernv_cpufreq_driver = { |
511 | .name = "powernv-cpufreq", | |
512 | .flags = CPUFREQ_CONST_LOOPS, | |
513 | .init = powernv_cpufreq_cpu_init, | |
514 | .verify = cpufreq_generic_frequency_table_verify, | |
515 | .target_index = powernv_cpufreq_target_index, | |
516 | .get = powernv_cpufreq_get, | |
b120339c | 517 | .stop_cpu = powernv_cpufreq_stop_cpu, |
b3d627a5 VS |
518 | .attr = powernv_cpu_freq_attr, |
519 | }; | |
520 | ||
053819e0 SB |
521 | static int init_chip_info(void) |
522 | { | |
523 | unsigned int chip[256]; | |
524 | unsigned int cpu, i; | |
525 | unsigned int prev_chip_id = UINT_MAX; | |
526 | ||
527 | for_each_possible_cpu(cpu) { | |
528 | unsigned int id = cpu_to_chip_id(cpu); | |
529 | ||
530 | if (prev_chip_id != id) { | |
531 | prev_chip_id = id; | |
532 | chip[nr_chips++] = id; | |
533 | } | |
534 | } | |
535 | ||
536 | chips = kmalloc_array(nr_chips, sizeof(struct chip), GFP_KERNEL); | |
537 | if (!chips) | |
538 | return -ENOMEM; | |
539 | ||
540 | for (i = 0; i < nr_chips; i++) { | |
541 | chips[i].id = chip[i]; | |
542 | chips[i].throttled = false; | |
735366fc SB |
543 | cpumask_copy(&chips[i].mask, cpumask_of_node(chip[i])); |
544 | INIT_WORK(&chips[i].throttle, powernv_cpufreq_work_fn); | |
053819e0 SB |
545 | } |
546 | ||
547 | return 0; | |
548 | } | |
549 | ||
b3d627a5 VS |
550 | static int __init powernv_cpufreq_init(void) |
551 | { | |
552 | int rc = 0; | |
553 | ||
6174bac8 VS |
554 | /* Don't probe on pseries (guest) platforms */ |
555 | if (!firmware_has_feature(FW_FEATURE_OPALv3)) | |
556 | return -ENODEV; | |
557 | ||
b3d627a5 VS |
558 | /* Discover pstates from device tree and init */ |
559 | rc = init_powernv_pstates(); | |
560 | if (rc) { | |
561 | pr_info("powernv-cpufreq disabled. System does not support PState control\n"); | |
562 | return rc; | |
563 | } | |
564 | ||
053819e0 SB |
565 | /* Populate chip info */ |
566 | rc = init_chip_info(); | |
567 | if (rc) | |
568 | return rc; | |
569 | ||
cf30af76 | 570 | register_reboot_notifier(&powernv_cpufreq_reboot_nb); |
cb166fa9 | 571 | opal_message_notifier_register(OPAL_MSG_OCC, &powernv_cpufreq_opal_nb); |
b3d627a5 VS |
572 | return cpufreq_register_driver(&powernv_cpufreq_driver); |
573 | } | |
574 | module_init(powernv_cpufreq_init); | |
575 | ||
576 | static void __exit powernv_cpufreq_exit(void) | |
577 | { | |
cf30af76 | 578 | unregister_reboot_notifier(&powernv_cpufreq_reboot_nb); |
cb166fa9 SB |
579 | opal_message_notifier_unregister(OPAL_MSG_OCC, |
580 | &powernv_cpufreq_opal_nb); | |
b3d627a5 VS |
581 | cpufreq_unregister_driver(&powernv_cpufreq_driver); |
582 | } | |
583 | module_exit(powernv_cpufreq_exit); | |
584 | ||
585 | MODULE_LICENSE("GPL"); | |
586 | MODULE_AUTHOR("Vaidyanathan Srinivasan <svaidy at linux.vnet.ibm.com>"); |