From 3ee7be9e10dd5f79448788b899591d4bd2bf0c19 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 6 Mar 2025 17:49:20 +0100 Subject: PM: EM: Address RCU-related sparse warnings The usage of __rcu in the Energy Model code is quite inconsistent which causes the following sparse warnings to trigger: kernel/power/energy_model.c:169:15: warning: incorrect type in assignment (different address spaces) kernel/power/energy_model.c:169:15: expected struct em_perf_table [noderef] __rcu *table kernel/power/energy_model.c:169:15: got struct em_perf_table * kernel/power/energy_model.c:171:9: warning: incorrect type in argument 1 (different address spaces) kernel/power/energy_model.c:171:9: expected struct callback_head *head kernel/power/energy_model.c:171:9: got struct callback_head [noderef] __rcu * kernel/power/energy_model.c:171:9: warning: cast removes address space '__rcu' of expression kernel/power/energy_model.c:182:19: warning: incorrect type in argument 1 (different address spaces) kernel/power/energy_model.c:182:19: expected struct kref *kref kernel/power/energy_model.c:182:19: got struct kref [noderef] __rcu * kernel/power/energy_model.c:200:15: warning: incorrect type in assignment (different address spaces) kernel/power/energy_model.c:200:15: expected struct em_perf_table [noderef] __rcu *table kernel/power/energy_model.c:200:15: got void *[assigned] _res kernel/power/energy_model.c:204:20: warning: incorrect type in argument 1 (different address spaces) kernel/power/energy_model.c:204:20: expected struct kref *kref kernel/power/energy_model.c:204:20: got struct kref [noderef] __rcu * kernel/power/energy_model.c:320:19: warning: incorrect type in argument 1 (different address spaces) kernel/power/energy_model.c:320:19: expected struct kref *kref kernel/power/energy_model.c:320:19: got struct kref [noderef] __rcu * kernel/power/energy_model.c:325:45: warning: incorrect type in argument 2 (different address spaces) kernel/power/energy_model.c:325:45: expected struct em_perf_state *table kernel/power/energy_model.c:325:45: got struct em_perf_state [noderef] __rcu * kernel/power/energy_model.c:425:45: warning: incorrect type in argument 3 (different address spaces) kernel/power/energy_model.c:425:45: expected struct em_perf_state *table kernel/power/energy_model.c:425:45: got struct em_perf_state [noderef] __rcu * kernel/power/energy_model.c:442:15: warning: incorrect type in argument 1 (different address spaces) kernel/power/energy_model.c:442:15: expected void const *objp kernel/power/energy_model.c:442:15: got struct em_perf_table [noderef] __rcu *[assigned] em_table kernel/power/energy_model.c:626:55: warning: incorrect type in argument 2 (different address spaces) kernel/power/energy_model.c:626:55: expected struct em_perf_state *table kernel/power/energy_model.c:626:55: got struct em_perf_state [noderef] __rcu * kernel/power/energy_model.c:681:16: warning: incorrect type in assignment (different address spaces) kernel/power/energy_model.c:681:16: expected struct em_perf_state *new_ps kernel/power/energy_model.c:681:16: got struct em_perf_state [noderef] __rcu * kernel/power/energy_model.c:699:37: warning: incorrect type in argument 2 (different address spaces) kernel/power/energy_model.c:699:37: expected struct em_perf_state *table kernel/power/energy_model.c:699:37: got struct em_perf_state [noderef] __rcu * kernel/power/energy_model.c:733:38: warning: incorrect type in argument 3 (different address spaces) kernel/power/energy_model.c:733:38: expected struct em_perf_state *table kernel/power/energy_model.c:733:38: got struct em_perf_state [noderef] __rcu * kernel/power/energy_model.c:855:53: warning: dereference of noderef expression kernel/power/energy_model.c:864:32: warning: dereference of noderef expression This is because the __rcu annotation for sparse is only applicable to pointers that need rcu_dereference() or equivalent for protection, which basically means pointers assigned with rcu_assign_pointer(). Make all of the above sparse warnings go away by cleaning up the usage of __rcu and using rcu_dereference_protected() where applicable. Cc: All applicable Signed-off-by: Rafael J. Wysocki Reviewed-by: Lukasz Luba Link: https://patch.msgid.link/5885405.DvuYhMxLoT@rjwysocki.net --- include/linux/energy_model.h | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'include/linux') diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index b23c8c798dac..ddd09debfc7d 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -167,13 +167,13 @@ struct em_data_callback { struct em_perf_domain *em_cpu_get(int cpu); struct em_perf_domain *em_pd_get(struct device *dev); int em_dev_update_perf_domain(struct device *dev, - struct em_perf_table __rcu *new_table); + struct em_perf_table *new_table); int em_dev_register_perf_domain(struct device *dev, unsigned int nr_states, const struct em_data_callback *cb, const cpumask_t *cpus, bool microwatts); void em_dev_unregister_perf_domain(struct device *dev); -struct em_perf_table __rcu *em_table_alloc(struct em_perf_domain *pd); -void em_table_free(struct em_perf_table __rcu *table); +struct em_perf_table *em_table_alloc(struct em_perf_domain *pd); +void em_table_free(struct em_perf_table *table); int em_dev_compute_costs(struct device *dev, struct em_perf_state *table, int nr_states); int em_dev_update_chip_binning(struct device *dev); @@ -373,14 +373,14 @@ static inline int em_pd_nr_perf_states(struct em_perf_domain *pd) return 0; } static inline -struct em_perf_table __rcu *em_table_alloc(struct em_perf_domain *pd) +struct em_perf_table *em_table_alloc(struct em_perf_domain *pd) { return NULL; } -static inline void em_table_free(struct em_perf_table __rcu *table) {} +static inline void em_table_free(struct em_perf_table *table) {} static inline int em_dev_update_perf_domain(struct device *dev, - struct em_perf_table __rcu *new_table) + struct em_perf_table *new_table) { return -EINVAL; } -- cgit v1.2.3