diff options
| -rw-r--r-- | kernel/cpu.c | 96 |
1 files changed, 50 insertions, 46 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index 5339aca811d2..3ff0ea5db371 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -1432,23 +1432,53 @@ static int cpuhp_cb_check(enum cpuhp_state state) return 0; } -static void cpuhp_store_callbacks(enum cpuhp_state state, - const char *name, - int (*startup)(unsigned int cpu), - int (*teardown)(unsigned int cpu), - bool multi_instance) +/* + * Returns a free for dynamic slot assignment of the Online state. The states + * are protected by the cpuhp_slot_states mutex and an empty slot is identified + * by having no name assigned. + */ +static int cpuhp_reserve_state(enum cpuhp_state state) +{ + enum cpuhp_state i; + + for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) { + if (!cpuhp_ap_states[i].name) + return i; + } + WARN(1, "No more dynamic states available for CPU hotplug\n"); + return -ENOSPC; +} + +static int cpuhp_store_callbacks(enum cpuhp_state state, const char *name, + int (*startup)(unsigned int cpu), + int (*teardown)(unsigned int cpu), + bool multi_instance) { /* (Un)Install the callbacks for further cpu hotplug operations */ struct cpuhp_step *sp; + int ret = 0; mutex_lock(&cpuhp_state_mutex); + + if (state == CPUHP_AP_ONLINE_DYN) { + ret = cpuhp_reserve_state(state); + if (ret < 0) + goto out; + state = ret; + } sp = cpuhp_get_step(state); + if (name && sp->name) { + ret = -EBUSY; + goto out; + } sp->startup.single = startup; sp->teardown.single = teardown; sp->name = name; sp->multi_instance = multi_instance; INIT_HLIST_HEAD(&sp->list); +out: mutex_unlock(&cpuhp_state_mutex); + return ret; } static void *cpuhp_get_teardown_cb(enum cpuhp_state state) @@ -1509,29 +1539,6 @@ static void cpuhp_rollback_install(int failedcpu, enum cpuhp_state state, } } -/* - * Returns a free for dynamic slot assignment of the Online state. The states - * are protected by the cpuhp_slot_states mutex and an empty slot is identified - * by having no name assigned. - */ -static int cpuhp_reserve_state(enum cpuhp_state state) -{ - enum cpuhp_state i; - - mutex_lock(&cpuhp_state_mutex); - for (i = CPUHP_AP_ONLINE_DYN; i <= CPUHP_AP_ONLINE_DYN_END; i++) { - if (cpuhp_ap_states[i].name) - continue; - - cpuhp_ap_states[i].name = "Reserved"; - mutex_unlock(&cpuhp_state_mutex); - return i; - } - mutex_unlock(&cpuhp_state_mutex); - WARN(1, "No more dynamic states available for CPU hotplug\n"); - return -ENOSPC; -} - int __cpuhp_state_add_instance(enum cpuhp_state state, struct hlist_node *node, bool invoke) { @@ -1580,11 +1587,13 @@ EXPORT_SYMBOL_GPL(__cpuhp_state_add_instance); /** * __cpuhp_setup_state - Setup the callbacks for an hotplug machine state - * @state: The state to setup - * @invoke: If true, the startup function is invoked for cpus where - * cpu state >= @state - * @startup: startup callback function - * @teardown: teardown callback function + * @state: The state to setup + * @invoke: If true, the startup function is invoked for cpus where + * cpu state >= @state + * @startup: startup callback function + * @teardown: teardown callback function + * @multi_instance: State is set up for multiple instances which get + * added afterwards. * * Returns: * On success: @@ -1599,25 +1608,16 @@ int __cpuhp_setup_state(enum cpuhp_state state, bool multi_instance) { int cpu, ret = 0; - int dyn_state = 0; if (cpuhp_cb_check(state) || !name) return -EINVAL; get_online_cpus(); - /* currently assignments for the ONLINE state are possible */ - if (state == CPUHP_AP_ONLINE_DYN) { - dyn_state = 1; - ret = cpuhp_reserve_state(state); - if (ret < 0) - goto out; - state = ret; - } - - cpuhp_store_callbacks(state, name, startup, teardown, multi_instance); + ret = cpuhp_store_callbacks(state, name, startup, teardown, + multi_instance); - if (!invoke || !startup) + if (ret || !invoke || !startup) goto out; /* @@ -1641,7 +1641,11 @@ int __cpuhp_setup_state(enum cpuhp_state state, } out: put_online_cpus(); - if (!ret && dyn_state) + /* + * If the requested state is CPUHP_AP_ONLINE_DYN, return the + * dynamically allocated state in case of success. + */ + if (!ret && state == CPUHP_AP_ONLINE_DYN) return state; return ret; } |