diff options
Diffstat (limited to 'kernel/cpu.c')
| -rw-r--r-- | kernel/cpu.c | 77 |
1 files changed, 49 insertions, 28 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c index ed44d7d34c2d..3c7f3b4c453c 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -102,8 +102,6 @@ static inline void cpuhp_lock_release(bool bringup) { } * @name: Name of the step * @startup: Startup function of the step * @teardown: Teardown function of the step - * @skip_onerr: Do not invoke the functions on error rollback - * Will go away once the notifiers are gone * @cant_stop: Bringup/teardown can't be stopped at this step */ struct cpuhp_step { @@ -119,7 +117,6 @@ struct cpuhp_step { struct hlist_node *node); } teardown; struct hlist_head list; - bool skip_onerr; bool cant_stop; bool multi_instance; }; @@ -318,6 +315,16 @@ void lockdep_assert_cpus_held(void) percpu_rwsem_assert_held(&cpu_hotplug_lock); } +static void lockdep_acquire_cpus_lock(void) +{ + rwsem_acquire(&cpu_hotplug_lock.rw_sem.dep_map, 0, 0, _THIS_IP_); +} + +static void lockdep_release_cpus_lock(void) +{ + rwsem_release(&cpu_hotplug_lock.rw_sem.dep_map, 1, _THIS_IP_); +} + /* * Wait for currently running CPU hotplug operations to complete (if any) and * disable future CPU hotplug (from sysfs). The 'cpu_add_remove_lock' protects @@ -347,6 +354,17 @@ void cpu_hotplug_enable(void) cpu_maps_update_done(); } EXPORT_SYMBOL_GPL(cpu_hotplug_enable); + +#else + +static void lockdep_acquire_cpus_lock(void) +{ +} + +static void lockdep_release_cpus_lock(void) +{ +} + #endif /* CONFIG_HOTPLUG_CPU */ #ifdef CONFIG_HOTPLUG_SMT @@ -365,6 +383,7 @@ void __init cpu_smt_disable(bool force) pr_info("SMT: Force disabled\n"); cpu_smt_control = CPU_SMT_FORCE_DISABLED; } else { + pr_info("SMT: disabled\n"); cpu_smt_control = CPU_SMT_DISABLED; } } @@ -550,12 +569,8 @@ static int bringup_cpu(unsigned int cpu) static void undo_cpu_up(unsigned int cpu, struct cpuhp_cpu_state *st) { - for (st->state--; st->state > st->target; st->state--) { - struct cpuhp_step *step = cpuhp_get_step(st->state); - - if (!step->skip_onerr) - cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL); - } + for (st->state--; st->state > st->target; st->state--) + cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL); } static int cpuhp_up_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, @@ -614,15 +629,21 @@ static void cpuhp_thread_fun(unsigned int cpu) bool bringup = st->bringup; enum cpuhp_state state; + if (WARN_ON_ONCE(!st->should_run)) + return; + /* * ACQUIRE for the cpuhp_should_run() load of ->should_run. Ensures * that if we see ->should_run we also see the rest of the state. */ smp_mb(); - if (WARN_ON_ONCE(!st->should_run)) - return; - + /* + * The BP holds the hotplug lock, but we're now running on the AP, + * ensure that anybody asserting the lock is held, will actually find + * it so. + */ + lockdep_acquire_cpus_lock(); cpuhp_lock_acquire(bringup); if (st->single) { @@ -644,12 +665,6 @@ static void cpuhp_thread_fun(unsigned int cpu) WARN_ON_ONCE(!cpuhp_is_ap_state(state)); - if (st->rollback) { - struct cpuhp_step *step = cpuhp_get_step(state); - if (step->skip_onerr) - goto next; - } - if (cpuhp_is_atomic_state(state)) { local_irq_disable(); st->result = cpuhp_invoke_callback(cpu, state, bringup, st->node, &st->last); @@ -673,8 +688,8 @@ static void cpuhp_thread_fun(unsigned int cpu) st->should_run = false; } -next: cpuhp_lock_release(bringup); + lockdep_release_cpus_lock(); if (!st->should_run) complete_ap_thread(st, bringup); @@ -916,12 +931,8 @@ void cpuhp_report_idle_dead(void) static void undo_cpu_down(unsigned int cpu, struct cpuhp_cpu_state *st) { - for (st->state++; st->state < st->target; st->state++) { - struct cpuhp_step *step = cpuhp_get_step(st->state); - - if (!step->skip_onerr) - cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL); - } + for (st->state++; st->state < st->target; st->state++) + cpuhp_invoke_callback(cpu, st->state, true, NULL, NULL); } static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, @@ -934,7 +945,8 @@ static int cpuhp_down_callbacks(unsigned int cpu, struct cpuhp_cpu_state *st, ret = cpuhp_invoke_callback(cpu, st->state, false, NULL, NULL); if (ret) { st->target = prev_state; - undo_cpu_down(cpu, st); + if (st->state < prev_state) + undo_cpu_down(cpu, st); break; } } @@ -987,7 +999,7 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen, * to do the further cleanups. */ ret = cpuhp_down_callbacks(cpu, st, target); - if (ret && st->state > CPUHP_TEARDOWN_CPU && st->state < prev_state) { + if (ret && st->state == CPUHP_TEARDOWN_CPU && st->state < prev_state) { cpuhp_reset_state(st, prev_state); __cpuhp_kick_ap(st); } @@ -2043,6 +2055,12 @@ static void cpuhp_online_cpu_device(unsigned int cpu) kobject_uevent(&dev->kobj, KOBJ_ONLINE); } +/* + * Architectures that need SMT-specific errata handling during SMT hotplug + * should override this. + */ +void __weak arch_smt_update(void) { }; + static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) { int cpu, ret = 0; @@ -2069,8 +2087,10 @@ static int cpuhp_smt_disable(enum cpuhp_smt_control ctrlval) */ cpuhp_offline_cpu_device(cpu); } - if (!ret) + if (!ret) { cpu_smt_control = ctrlval; + arch_smt_update(); + } cpu_maps_update_done(); return ret; } @@ -2081,6 +2101,7 @@ static int cpuhp_smt_enable(void) cpu_maps_update_begin(); cpu_smt_control = CPU_SMT_ENABLED; + arch_smt_update(); for_each_present_cpu(cpu) { /* Skip online CPUs and CPUs on offline nodes */ if (cpu_online(cpu) || !node_online(cpu_to_node(cpu))) |