Hi Lukasz, I love your patch! Perhaps something to improve: [auto build test WARNING on next-20200409] [cannot apply to pm/linux-next tip/sched/core linus/master linux/master v5.6 v5.6-rc7 v5.6-rc6 v5.6] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system. BTW, we also suggest to use '--base' option to specify the base tree in git format-patch, please see https://stackoverflow.com/a/37406982] url: https://github.com/0day-ci/linux/commits/Lukasz-Luba/Add-support-for-devices-in-the-Energy-Model/20200410-172456 base: 873e37a44b1ee8ad4628ca257dc51c0c7c654326 If you fix the issue, kindly add following tag as appropriate Reported-by: kbuild test robot <lkp@xxxxxxxxx> cppcheck warnings: (new ones prefixed by >>) >> kernel/power/energy_model.c:394:15: warning: Variable 'ret' is assigned a value that is never used. [unreadVariable] int cpu, ret = 0; ^ vim +/ret +394 kernel/power/energy_model.c 27871f7a8a341e Quentin Perret 2018-12-03 370 27871f7a8a341e Quentin Perret 2018-12-03 371 /** b4dc5cca354b8a Lukasz Luba 2020-04-10 372 * em_dev_register_perf_domain() - Register the Energy Model (EM) for a device b4dc5cca354b8a Lukasz Luba 2020-04-10 373 * @dev : Device for which the EM is to register 1ccc27ced21bf5 Lukasz Luba 2020-04-10 374 * @nr_states : Number of performance states to register 27871f7a8a341e Quentin Perret 2018-12-03 375 * @cb : Callback functions providing the data of the Energy Model 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 376 * @cpus : Pointer to cpumask_t, which in case of a CPU device is b4dc5cca354b8a Lukasz Luba 2020-04-10 377 * obligatory. It can be taken from i.e. 'policy->cpus'. For other b4dc5cca354b8a Lukasz Luba 2020-04-10 378 * type of devices this should be set to NULL. 27871f7a8a341e Quentin Perret 2018-12-03 379 * 27871f7a8a341e Quentin Perret 2018-12-03 380 * Create Energy Model tables for a performance domain using the callbacks 27871f7a8a341e Quentin Perret 2018-12-03 381 * defined in cb. 27871f7a8a341e Quentin Perret 2018-12-03 382 * 27871f7a8a341e Quentin Perret 2018-12-03 383 * If multiple clients register the same performance domain, all but the first 27871f7a8a341e Quentin Perret 2018-12-03 384 * registration will be ignored. 27871f7a8a341e Quentin Perret 2018-12-03 385 * 27871f7a8a341e Quentin Perret 2018-12-03 386 * Return 0 on success 27871f7a8a341e Quentin Perret 2018-12-03 387 */ b4dc5cca354b8a Lukasz Luba 2020-04-10 388 int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 389 struct em_data_callback *cb, cpumask_t *cpus) 27871f7a8a341e Quentin Perret 2018-12-03 390 { 27871f7a8a341e Quentin Perret 2018-12-03 391 unsigned long cap, prev_cap = 0; 27871f7a8a341e Quentin Perret 2018-12-03 392 struct em_perf_domain *pd; 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 393 struct em_device *em_dev; 27871f7a8a341e Quentin Perret 2018-12-03 @394 int cpu, ret = 0; 27871f7a8a341e Quentin Perret 2018-12-03 395 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 396 if (!dev || !nr_states || !cb) 27871f7a8a341e Quentin Perret 2018-12-03 397 return -EINVAL; 27871f7a8a341e Quentin Perret 2018-12-03 398 27871f7a8a341e Quentin Perret 2018-12-03 399 /* 27871f7a8a341e Quentin Perret 2018-12-03 400 * Use a mutex to serialize the registration of performance domains and 27871f7a8a341e Quentin Perret 2018-12-03 401 * let the driver-defined callback functions sleep. 27871f7a8a341e Quentin Perret 2018-12-03 402 */ 27871f7a8a341e Quentin Perret 2018-12-03 403 mutex_lock(&em_pd_mutex); 27871f7a8a341e Quentin Perret 2018-12-03 404 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 405 em_dev = _em_dev_find_existing(dev); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 406 if (em_dev) { 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 407 mutex_unlock(&em_pd_mutex); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 408 dev_dbg(dev, "EM: found exisiting pd%d\n", em_dev->id); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 409 return -EEXIST; 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 410 } 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 411 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 412 if (_is_cpu_device(dev)) { 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 413 if (!cpus) { 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 414 mutex_unlock(&em_pd_mutex); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 415 dev_err(dev, "EM: invalid CPU mask\n"); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 416 return -EINVAL; 27871f7a8a341e Quentin Perret 2018-12-03 417 } 27871f7a8a341e Quentin Perret 2018-12-03 418 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 419 /* Make sure we don't register domain for existing CPUs */ 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 420 if (em_cpus_pd_exist(cpus)) { 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 421 mutex_unlock(&em_pd_mutex); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 422 return -EEXIST; 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 423 } 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 424 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 425 for_each_cpu(cpu, cpus) { 27871f7a8a341e Quentin Perret 2018-12-03 426 /* 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 427 * All CPUs of a domain must have the same 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 428 * micro-architecture since they all share the same 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 429 * table. 27871f7a8a341e Quentin Perret 2018-12-03 430 */ 8ec59c0f5f4966 Vincent Guittot 2019-06-17 431 cap = arch_scale_cpu_capacity(cpu); 27871f7a8a341e Quentin Perret 2018-12-03 432 if (prev_cap && prev_cap != cap) { 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 433 dev_err(dev, "EM: CPUs of %*pbl must have the same capacity\n", 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 434 cpumask_pr_args(cpus)); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 435 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 436 mutex_unlock(&em_pd_mutex); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 437 return -EINVAL; 27871f7a8a341e Quentin Perret 2018-12-03 438 } 27871f7a8a341e Quentin Perret 2018-12-03 439 prev_cap = cap; 27871f7a8a341e Quentin Perret 2018-12-03 440 } 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 441 } 27871f7a8a341e Quentin Perret 2018-12-03 442 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 443 pd = em_create_pd(dev, nr_states, cb, cpus); 27871f7a8a341e Quentin Perret 2018-12-03 444 if (!pd) { 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 445 mutex_unlock(&em_pd_mutex); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 446 return -EINVAL; 27871f7a8a341e Quentin Perret 2018-12-03 447 } 27871f7a8a341e Quentin Perret 2018-12-03 448 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 449 em_dev = kzalloc(sizeof(struct em_device), GFP_KERNEL); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 450 if (!em_dev) { 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 451 ret = -ENOMEM; 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 452 goto free_pd; 27871f7a8a341e Quentin Perret 2018-12-03 453 } 27871f7a8a341e Quentin Perret 2018-12-03 454 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 455 em_dev->id = ida_simple_get(&em_dev_ida, 0, 0, GFP_KERNEL); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 456 if (em_dev->id < 0) { 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 457 ret = em_dev->id; 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 458 goto free_em_dev; 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 459 } 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 460 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 461 em_dev->em_pd = pd; 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 462 em_dev->dev = dev; 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 463 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 464 kref_init(&em_dev->kref); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 465 list_add(&em_dev->em_dev_list, &em_pd_dev_list); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 466 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 467 em_debug_create_pd(em_dev); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 468 dev_dbg(dev, "EM: created perf domain pd%d\n", em_dev->id); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 469 27871f7a8a341e Quentin Perret 2018-12-03 470 mutex_unlock(&em_pd_mutex); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 471 return 0; 27871f7a8a341e Quentin Perret 2018-12-03 472 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 473 free_em_dev: 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 474 kfree(em_dev); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 475 free_pd: 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 476 kfree(pd->table); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 477 kfree(pd); 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 478 9cf8494b5f4eb8 Lukasz Luba 2020-04-10 479 mutex_unlock(&em_pd_mutex); 27871f7a8a341e Quentin Perret 2018-12-03 480 return ret; 27871f7a8a341e Quentin Perret 2018-12-03 481 } b4dc5cca354b8a Lukasz Luba 2020-04-10 482 EXPORT_SYMBOL_GPL(em_dev_register_perf_domain); b4dc5cca354b8a Lukasz Luba 2020-04-10 483 :::::: The code at line 394 was first introduced by commit :::::: 27871f7a8a341ef5c636a337856369acf8013e4e PM: Introduce an Energy Model management framework :::::: TO: Quentin Perret <quentin.perret@xxxxxxx> :::::: CC: Ingo Molnar <mingo@xxxxxxxxxx> --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
