1
2
3
4
5
6
7#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
8
9#include <linux/atomic.h>
10#include <linux/completion.h>
11#include <linux/cpu.h>
12#include <linux/cpuidle.h>
13#include <linux/cpu_pm.h>
14#include <linux/kernel.h>
15#include <linux/kthread.h>
16#include <uapi/linux/sched/types.h>
17#include <linux/module.h>
18#include <linux/preempt.h>
19#include <linux/psci.h>
20#include <linux/slab.h>
21#include <linux/tick.h>
22#include <linux/topology.h>
23
24#include <asm/cpuidle.h>
25
26#include <uapi/linux/psci.h>
27
28#define NUM_SUSPEND_CYCLE (10)
29
30static unsigned int nb_available_cpus;
31static int tos_resident_cpu = -1;
32
33static atomic_t nb_active_threads;
34static struct completion suspend_threads_started =
35 COMPLETION_INITIALIZER(suspend_threads_started);
36static struct completion suspend_threads_done =
37 COMPLETION_INITIALIZER(suspend_threads_done);
38
39
40
41
42
43
44
45static int psci_ops_check(void)
46{
47 int migrate_type = -1;
48 int cpu;
49
50 if (!(psci_ops.cpu_off && psci_ops.cpu_on && psci_ops.cpu_suspend)) {
51 pr_warn("Missing PSCI operations, aborting tests\n");
52 return -EOPNOTSUPP;
53 }
54
55 if (psci_ops.migrate_info_type)
56 migrate_type = psci_ops.migrate_info_type();
57
58 if (migrate_type == PSCI_0_2_TOS_UP_MIGRATE ||
59 migrate_type == PSCI_0_2_TOS_UP_NO_MIGRATE) {
60
61 for_each_online_cpu(cpu)
62 if (psci_tos_resident_on(cpu)) {
63 tos_resident_cpu = cpu;
64 break;
65 }
66 if (tos_resident_cpu == -1)
67 pr_warn("UP Trusted OS resides on no online CPU\n");
68 }
69
70 return 0;
71}
72
73
74
75
76
77static unsigned int down_and_up_cpus(const struct cpumask *cpus,
78 struct cpumask *offlined_cpus)
79{
80 int cpu;
81 int err = 0;
82
83 cpumask_clear(offlined_cpus);
84
85
86 for_each_cpu(cpu, cpus) {
87 int ret = remove_cpu(cpu);
88
89
90
91
92
93 if (cpumask_weight(offlined_cpus) + 1 == nb_available_cpus) {
94 if (ret != -EBUSY) {
95 pr_err("Unexpected return code %d while trying "
96 "to power down last online CPU %d\n",
97 ret, cpu);
98 ++err;
99 }
100 } else if (cpu == tos_resident_cpu) {
101 if (ret != -EPERM) {
102 pr_err("Unexpected return code %d while trying "
103 "to power down TOS resident CPU %d\n",
104 ret, cpu);
105 ++err;
106 }
107 } else if (ret != 0) {
108 pr_err("Error occurred (%d) while trying "
109 "to power down CPU %d\n", ret, cpu);
110 ++err;
111 }
112
113 if (ret == 0)
114 cpumask_set_cpu(cpu, offlined_cpus);
115 }
116
117
118 for_each_cpu(cpu, offlined_cpus) {
119 int ret = add_cpu(cpu);
120
121 if (ret != 0) {
122 pr_err("Error occurred (%d) while trying "
123 "to power up CPU %d\n", ret, cpu);
124 ++err;
125 } else {
126 cpumask_clear_cpu(cpu, offlined_cpus);
127 }
128 }
129
130
131
132
133
134 WARN_ON(!cpumask_empty(offlined_cpus) ||
135 num_online_cpus() != nb_available_cpus);
136
137 return err;
138}
139
140static void free_cpu_groups(int num, cpumask_var_t **pcpu_groups)
141{
142 int i;
143 cpumask_var_t *cpu_groups = *pcpu_groups;
144
145 for (i = 0; i < num; ++i)
146 free_cpumask_var(cpu_groups[i]);
147 kfree(cpu_groups);
148}
149
150static int alloc_init_cpu_groups(cpumask_var_t **pcpu_groups)
151{
152 int num_groups = 0;
153 cpumask_var_t tmp, *cpu_groups;
154
155 if (!alloc_cpumask_var(&tmp, GFP_KERNEL))
156 return -ENOMEM;
157
158 cpu_groups = kcalloc(nb_available_cpus, sizeof(cpu_groups),
159 GFP_KERNEL);
160 if (!cpu_groups) {
161 free_cpumask_var(tmp);
162 return -ENOMEM;
163 }
164
165 cpumask_copy(tmp, cpu_online_mask);
166
167 while (!cpumask_empty(tmp)) {
168 const struct cpumask *cpu_group =
169 topology_core_cpumask(cpumask_any(tmp));
170
171 if (!alloc_cpumask_var(&cpu_groups[num_groups], GFP_KERNEL)) {
172 free_cpumask_var(tmp);
173 free_cpu_groups(num_groups, &cpu_groups);
174 return -ENOMEM;
175 }
176 cpumask_copy(cpu_groups[num_groups++], cpu_group);
177 cpumask_andnot(tmp, tmp, cpu_group);
178 }
179
180 free_cpumask_var(tmp);
181 *pcpu_groups = cpu_groups;
182
183 return num_groups;
184}
185
186static int hotplug_tests(void)
187{
188 int i, nb_cpu_group, err = -ENOMEM;
189 cpumask_var_t offlined_cpus, *cpu_groups;
190 char *page_buf;
191
192 if (!alloc_cpumask_var(&offlined_cpus, GFP_KERNEL))
193 return err;
194
195 nb_cpu_group = alloc_init_cpu_groups(&cpu_groups);
196 if (nb_cpu_group < 0)
197 goto out_free_cpus;
198 page_buf = (char *)__get_free_page(GFP_KERNEL);
199 if (!page_buf)
200 goto out_free_cpu_groups;
201
202
203
204
205
206 pr_info("Trying to turn off and on again all CPUs\n");
207 err = down_and_up_cpus(cpu_online_mask, offlined_cpus);
208
209
210
211
212
213 for (i = 0; i < nb_cpu_group; ++i) {
214 ssize_t len = cpumap_print_to_pagebuf(true, page_buf,
215 cpu_groups[i]);
216
217 page_buf[len - 1] = '\0';
218 pr_info("Trying to turn off and on again group %d (CPUs %s)\n",
219 i, page_buf);
220 err += down_and_up_cpus(cpu_groups[i], offlined_cpus);
221 }
222
223 free_page((unsigned long)page_buf);
224out_free_cpu_groups:
225 free_cpu_groups(nb_cpu_group, &cpu_groups);
226out_free_cpus:
227 free_cpumask_var(offlined_cpus);
228 return err;
229}
230
231static void dummy_callback(struct timer_list *unused) {}
232
233static int suspend_cpu(struct cpuidle_device *dev,
234 struct cpuidle_driver *drv, int index)
235{
236 struct cpuidle_state *state = &drv->states[index];
237 bool broadcast = state->flags & CPUIDLE_FLAG_TIMER_STOP;
238 int ret;
239
240 arch_cpu_idle_enter();
241
242 if (broadcast) {
243
244
245
246
247 ret = tick_broadcast_enter();
248 if (ret) {
249
250
251
252
253
254
255
256 cpu_do_idle();
257 ret = 0;
258 goto out_arch_exit;
259 }
260 }
261
262 ret = state->enter(dev, drv, index);
263
264 if (broadcast)
265 tick_broadcast_exit();
266
267out_arch_exit:
268 arch_cpu_idle_exit();
269
270 return ret;
271}
272
273static int suspend_test_thread(void *arg)
274{
275 int cpu = (long)arg;
276 int i, nb_suspend = 0, nb_shallow_sleep = 0, nb_err = 0;
277 struct cpuidle_device *dev;
278 struct cpuidle_driver *drv;
279
280 struct timer_list wakeup_timer;
281
282
283 wait_for_completion(&suspend_threads_started);
284
285
286 sched_set_fifo(current);
287
288 dev = this_cpu_read(cpuidle_devices);
289 drv = cpuidle_get_cpu_driver(dev);
290
291 pr_info("CPU %d entering suspend cycles, states 1 through %d\n",
292 cpu, drv->state_count - 1);
293
294 timer_setup_on_stack(&wakeup_timer, dummy_callback, 0);
295 for (i = 0; i < NUM_SUSPEND_CYCLE; ++i) {
296 int index;
297
298
299
300
301 for (index = 1; index < drv->state_count; ++index) {
302 int ret;
303 struct cpuidle_state *state = &drv->states[index];
304
305
306
307
308
309
310
311
312 mod_timer(&wakeup_timer, jiffies +
313 usecs_to_jiffies(state->target_residency));
314
315
316 local_irq_disable();
317
318 ret = suspend_cpu(dev, drv, index);
319
320
321
322
323
324
325 local_irq_enable();
326
327 if (ret == index) {
328 ++nb_suspend;
329 } else if (ret >= 0) {
330
331 ++nb_shallow_sleep;
332 } else {
333 pr_err("Failed to suspend CPU %d: error %d "
334 "(requested state %d, cycle %d)\n",
335 cpu, ret, index, i);
336 ++nb_err;
337 }
338 }
339 }
340
341
342
343
344
345 del_timer(&wakeup_timer);
346 destroy_timer_on_stack(&wakeup_timer);
347
348 if (atomic_dec_return_relaxed(&nb_active_threads) == 0)
349 complete(&suspend_threads_done);
350
351 for (;;) {
352
353 set_current_state(TASK_INTERRUPTIBLE);
354 if (kthread_should_park())
355 break;
356 schedule();
357 }
358
359 pr_info("CPU %d suspend test results: success %d, shallow states %d, errors %d\n",
360 cpu, nb_suspend, nb_shallow_sleep, nb_err);
361
362 kthread_parkme();
363
364 return nb_err;
365}
366
367static int suspend_tests(void)
368{
369 int i, cpu, err = 0;
370 struct task_struct **threads;
371 int nb_threads = 0;
372
373 threads = kmalloc_array(nb_available_cpus, sizeof(*threads),
374 GFP_KERNEL);
375 if (!threads)
376 return -ENOMEM;
377
378
379
380
381
382
383
384
385 cpuidle_pause_and_lock();
386
387 for_each_online_cpu(cpu) {
388 struct task_struct *thread;
389
390 struct cpuidle_device *dev = per_cpu(cpuidle_devices, cpu);
391 struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
392
393 if (!dev || !drv) {
394 pr_warn("cpuidle not available on CPU %d, ignoring\n",
395 cpu);
396 continue;
397 }
398
399 thread = kthread_create_on_cpu(suspend_test_thread,
400 (void *)(long)cpu, cpu,
401 "psci_suspend_test");
402 if (IS_ERR(thread))
403 pr_err("Failed to create kthread on CPU %d\n", cpu);
404 else
405 threads[nb_threads++] = thread;
406 }
407
408 if (nb_threads < 1) {
409 err = -ENODEV;
410 goto out;
411 }
412
413 atomic_set(&nb_active_threads, nb_threads);
414
415
416
417
418
419
420 for (i = 0; i < nb_threads; ++i)
421 wake_up_process(threads[i]);
422 complete_all(&suspend_threads_started);
423
424 wait_for_completion(&suspend_threads_done);
425
426
427
428 for (i = 0; i < nb_threads; ++i) {
429 err += kthread_park(threads[i]);
430 err += kthread_stop(threads[i]);
431 }
432 out:
433 cpuidle_resume_and_unlock();
434 kfree(threads);
435 return err;
436}
437
438static int __init psci_checker(void)
439{
440 int ret;
441
442
443
444
445
446
447
448
449
450
451 nb_available_cpus = num_online_cpus();
452
453
454 ret = psci_ops_check();
455 if (ret)
456 return ret;
457
458 pr_info("PSCI checker started using %u CPUs\n", nb_available_cpus);
459
460 pr_info("Starting hotplug tests\n");
461 ret = hotplug_tests();
462 if (ret == 0)
463 pr_info("Hotplug tests passed OK\n");
464 else if (ret > 0)
465 pr_err("%d error(s) encountered in hotplug tests\n", ret);
466 else {
467 pr_err("Out of memory\n");
468 return ret;
469 }
470
471 pr_info("Starting suspend tests (%d cycles per state)\n",
472 NUM_SUSPEND_CYCLE);
473 ret = suspend_tests();
474 if (ret == 0)
475 pr_info("Suspend tests passed OK\n");
476 else if (ret > 0)
477 pr_err("%d error(s) encountered in suspend tests\n", ret);
478 else {
479 switch (ret) {
480 case -ENOMEM:
481 pr_err("Out of memory\n");
482 break;
483 case -ENODEV:
484 pr_warn("Could not start suspend tests on any CPU\n");
485 break;
486 }
487 }
488
489 pr_info("PSCI checker completed\n");
490 return ret < 0 ? ret : 0;
491}
492late_initcall(psci_checker);
493