From cf4ce59b3b70238352c7f1729f0f7223214828ad Mon Sep 17 00:00:00 2001 From: hc <hc@nodka.com> Date: Fri, 20 Sep 2024 01:46:19 +0000 Subject: [PATCH] rtl88x2CE_WiFi_linux add concurrent mode --- kernel/kernel/irq/manage.c | 615 +++++++++++++++++++++++++++++++++++++++++++++++-------- 1 files changed, 527 insertions(+), 88 deletions(-) diff --git a/kernel/kernel/irq/manage.c b/kernel/kernel/irq/manage.c index c7ee23f..87b2fbf 100644 --- a/kernel/kernel/irq/manage.c +++ b/kernel/kernel/irq/manage.c @@ -18,13 +18,13 @@ #include <linux/sched.h> #include <linux/sched/rt.h> #include <linux/sched/task.h> +#include <linux/sched/isolation.h> #include <uapi/linux/sched/types.h> #include <linux/task_work.h> #include "internals.h" -#ifdef CONFIG_IRQ_FORCED_THREADING -# ifndef CONFIG_PREEMPT_RT_BASE +#if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT) __read_mostly bool force_irqthreads; EXPORT_SYMBOL_GPL(force_irqthreads); @@ -34,7 +34,6 @@ return 0; } early_param("threadirqs", setup_forced_irqthreads); -# endif #endif static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip) @@ -224,16 +223,70 @@ { struct irq_desc *desc = irq_data_to_desc(data); struct irq_chip *chip = irq_data_get_irq_chip(data); + const struct cpumask *prog_mask; int ret; + + static DEFINE_RAW_SPINLOCK(tmp_mask_lock); + static struct cpumask tmp_mask; if (!chip || !chip->irq_set_affinity) return -EINVAL; - ret = chip->irq_set_affinity(data, mask, force); + raw_spin_lock(&tmp_mask_lock); + /* + * If this is a managed interrupt and housekeeping is enabled on + * it check whether the requested affinity mask intersects with + * a housekeeping CPU. If so, then remove the isolated CPUs from + * the mask and just keep the housekeeping CPU(s). This prevents + * the affinity setter from routing the interrupt to an isolated + * CPU to avoid that I/O submitted from a housekeeping CPU causes + * interrupts on an isolated one. + * + * If the masks do not intersect or include online CPU(s) then + * keep the requested mask. The isolated target CPUs are only + * receiving interrupts when the I/O operation was submitted + * directly from them. + * + * If all housekeeping CPUs in the affinity mask are offline, the + * interrupt will be migrated by the CPU hotplug code once a + * housekeeping CPU which belongs to the affinity mask comes + * online. + */ + if (irqd_affinity_is_managed(data) && + housekeeping_enabled(HK_FLAG_MANAGED_IRQ)) { + const struct cpumask *hk_mask; + + hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ); + + cpumask_and(&tmp_mask, mask, hk_mask); + if (!cpumask_intersects(&tmp_mask, cpu_online_mask)) + prog_mask = mask; + else + prog_mask = &tmp_mask; + } else { + prog_mask = mask; + } + + /* + * Make sure we only provide online CPUs to the irqchip, + * unless we are being asked to force the affinity (in which + * case we do as we are told). + */ + cpumask_and(&tmp_mask, prog_mask, cpu_online_mask); + if (!force && !cpumask_empty(&tmp_mask)) + ret = chip->irq_set_affinity(data, &tmp_mask, force); + else if (force) + ret = chip->irq_set_affinity(data, mask, force); + else + ret = -EINVAL; + + raw_spin_unlock(&tmp_mask_lock); + switch (ret) { case IRQ_SET_MASK_OK: case IRQ_SET_MASK_OK_DONE: cpumask_copy(desc->irq_common_data.affinity, mask); + fallthrough; case IRQ_SET_MASK_OK_NOCOPY: irq_validate_effective_affinity(data); irq_set_thread_affinity(desc); @@ -242,6 +295,7 @@ return ret; } +EXPORT_SYMBOL_GPL(irq_do_set_affinity); #ifdef CONFIG_GENERIC_PENDING_IRQ static inline int irq_set_affinity_pending(struct irq_data *data, @@ -288,7 +342,7 @@ * If the interrupt is not yet activated, just store the affinity * mask and do not call the chip driver at all. On activation the * driver has to make sure anyway that the interrupt is in a - * useable state so startup works. + * usable state so startup works. */ if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) || irqd_is_activated(data) || !irqd_affinity_on_activate(data)) @@ -347,7 +401,6 @@ raw_spin_unlock_irqrestore(&desc->lock, flags); return ret; } -EXPORT_SYMBOL_GPL(__irq_set_affinity); int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m) { @@ -411,7 +464,7 @@ /* The release function is promised process context */ might_sleep(); - if (!desc) + if (!desc || desc->istate & IRQS_NMI) return -EINVAL; /* Complete initialisation of *notify */ @@ -614,6 +667,21 @@ } EXPORT_SYMBOL_GPL(disable_hardirq); +/** + * disable_nmi_nosync - disable an nmi without waiting + * @irq: Interrupt to disable + * + * Disable the selected interrupt line. Disables and enables are + * nested. + * The interrupt to disable must have been requested through request_nmi. + * Unlike disable_nmi(), this function does not ensure existing + * instances of the IRQ handler have completed before returning. + */ +void disable_nmi_nosync(unsigned int irq) +{ + disable_irq_nosync(irq); +} + void __enable_irq(struct irq_desc *desc) { switch (desc->depth) { @@ -670,6 +738,20 @@ } EXPORT_SYMBOL(enable_irq); +/** + * enable_nmi - enable handling of an nmi + * @irq: Interrupt to enable + * + * The interrupt to enable must have been requested through request_nmi. + * Undoes the effect of one call to disable_nmi(). If this + * matches the last disable, processing of interrupts on this + * IRQ line is re-enabled. + */ +void enable_nmi(unsigned int irq) +{ + enable_irq(irq); +} + static int set_irq_wake_real(unsigned int irq, unsigned int on) { struct irq_desc *desc = irq_to_desc(irq); @@ -695,6 +777,13 @@ * * Wakeup mode lets this IRQ wake the system from sleep * states like "suspend to RAM". + * + * Note: irq enable/disable state is completely orthogonal + * to the enable/disable state of irq wake. An irq can be + * disabled with disable_irq() and still wake the system as + * long as the irq has wake enabled. If this does not hold, + * then the underlying irq chip and the related driver need + * to be investigated. */ int irq_set_irq_wake(unsigned int irq, unsigned int on) { @@ -704,6 +793,12 @@ if (!desc) return -EINVAL; + + /* Don't use NMIs as wake up interrupts please */ + if (desc->istate & IRQS_NMI) { + ret = -EINVAL; + goto out_unlock; + } /* wakeup-capable irqs can be shared between drivers that * don't need to have the same sleep mode behaviors. @@ -727,6 +822,8 @@ irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE); } } + +out_unlock: irq_put_desc_busunlock(desc, flags); return ret; } @@ -787,6 +884,7 @@ case IRQ_SET_MASK_OK_DONE: irqd_clear(&desc->irq_data, IRQD_TRIGGER_MASK); irqd_set(&desc->irq_data, flags); + fallthrough; case IRQ_SET_MASK_OK_NOCOPY: flags = irqd_get_trigger_type(&desc->irq_data); @@ -801,7 +899,7 @@ ret = 0; break; default: - pr_err("Setting trigger mode %lu for irq %u failed (%pF)\n", + pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n", flags, irq_desc_get_irq(desc), chip->irq_set_type); } if (unmask) @@ -902,7 +1000,7 @@ * to IRQS_INPROGRESS and the irq line is masked forever. * * This also serializes the state of shared oneshot handlers - * versus "desc->threads_onehsot |= action->thread_mask;" in + * versus "desc->threads_oneshot |= action->thread_mask;" in * irq_wake_thread(). See the comment there which explains the * serialization. */ @@ -979,7 +1077,7 @@ #endif /* - * Interrupts which are not explicitely requested as threaded + * Interrupts which are not explicitly requested as threaded * interrupts rely on the implicit bh/preempt disable of the hard irq * context. So we need to disable bh here to avoid deadlocks and other * side effects. @@ -990,14 +1088,14 @@ irqreturn_t ret; local_bh_disable(); - if (!IS_ENABLED(CONFIG_PREEMPT_RT_BASE)) + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) local_irq_disable(); ret = action->thread_fn(action->irq, action->dev_id); if (ret == IRQ_HANDLED) atomic_inc(&desc->threads_handled); irq_finalize_oneshot(desc, action); - if (!IS_ENABLED(CONFIG_PREEMPT_RT_BASE)) + if (!IS_ENABLED(CONFIG_PREEMPT_RT)) local_irq_enable(); local_bh_enable(); return ret; @@ -1067,6 +1165,31 @@ } /* + * Internal function to notify that a interrupt thread is ready. + */ +static void irq_thread_set_ready(struct irq_desc *desc, + struct irqaction *action) +{ + set_bit(IRQTF_READY, &action->thread_flags); + wake_up(&desc->wait_for_threads); +} + +/* + * Internal function to wake up a interrupt thread and wait until it is + * ready. + */ +static void wake_up_and_wait_for_irq_thread_ready(struct irq_desc *desc, + struct irqaction *action) +{ + if (!action || !action->thread) + return; + + wake_up_process(action->thread); + wait_event(desc->wait_for_threads, + test_bit(IRQTF_READY, &action->thread_flags)); +} + +/* * Interrupt handler thread */ static int irq_thread(void *data) @@ -1077,6 +1200,8 @@ irqreturn_t (*handler_fn)(struct irq_desc *desc, struct irqaction *action); + irq_thread_set_ready(desc, action); + if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD, &action->thread_flags)) handler_fn = irq_forced_thread_fn; @@ -1084,7 +1209,7 @@ handler_fn = irq_thread_fn; init_task_work(&on_exit_work, irq_thread_dtor); - task_work_add(current, &on_exit_work, false); + task_work_add(current, &on_exit_work, TWA_NONE); irq_thread_check_affinity(desc, action); @@ -1097,12 +1222,6 @@ if (action_ret == IRQ_WAKE_THREAD) irq_wake_secondary(desc, action); -#ifdef CONFIG_PREEMPT_RT_FULL - migrate_disable(); - add_interrupt_randomness(action->irq, 0, - desc->random_ip ^ (unsigned long) action); - migrate_enable(); -#endif wake_threads_waitq(desc); } @@ -1199,13 +1318,43 @@ c->irq_release_resources(d); } +static bool irq_supports_nmi(struct irq_desc *desc) +{ + struct irq_data *d = irq_desc_get_irq_data(desc); + +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY + /* Only IRQs directly managed by the root irqchip can be set as NMI */ + if (d->parent_data) + return false; +#endif + /* Don't support NMIs for chips behind a slow bus */ + if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock) + return false; + + return d->chip->flags & IRQCHIP_SUPPORTS_NMI; +} + +static int irq_nmi_setup(struct irq_desc *desc) +{ + struct irq_data *d = irq_desc_get_irq_data(desc); + struct irq_chip *c = d->chip; + + return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL; +} + +static void irq_nmi_teardown(struct irq_desc *desc) +{ + struct irq_data *d = irq_desc_get_irq_data(desc); + struct irq_chip *c = d->chip; + + if (c->irq_nmi_teardown) + c->irq_nmi_teardown(d); +} + static int setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary) { struct task_struct *t; - struct sched_param param = { - .sched_priority = MAX_USER_RT_PRIO/2, - }; if (!secondary) { t = kthread_create(irq_thread, new, "irq/%d-%s", irq, @@ -1213,21 +1362,19 @@ } else { t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq, new->name); - param.sched_priority -= 1; } if (IS_ERR(t)) return PTR_ERR(t); - sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m); + sched_set_fifo(t); /* * We keep the reference to the task struct even if * the thread dies to avoid that the interrupt code * references an already freed task_struct. */ - get_task_struct(t); - new->thread = t; + new->thread = get_task_struct(t); /* * Tell the thread to set its affinity. This is * important for shared interrupt handlers as we do @@ -1373,8 +1520,16 @@ * fields must have IRQF_SHARED set and the bits which * set the trigger type must match. Also all must * agree on ONESHOT. + * Interrupt lines used for NMIs cannot be shared. */ unsigned int oldtype; + + if (desc->istate & IRQS_NMI) { + pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n", + new->name, irq, desc->irq_data.chip->name); + ret = -EINVAL; + goto out_unlock; + } /* * If nobody did set the configuration before, inherit @@ -1464,15 +1619,13 @@ * has. The type flags are unreliable as the * underlying chip implementation can override them. */ - pr_err("Threaded irq requested with handler=NULL and !ONESHOT for irq %d\n", - irq); + pr_err("Threaded irq requested with handler=NULL and !ONESHOT for %s (irq %d)\n", + new->name, irq); ret = -EINVAL; goto out_unlock; } if (!shared) { - init_waitqueue_head(&desc->wait_for_threads); - /* Setup the type (level, edge polarity) if configured: */ if (new->flags & IRQF_TRIGGER_MASK) { ret = __irq_set_trigger(desc, @@ -1515,10 +1668,8 @@ irqd_set(&desc->irq_data, IRQD_NO_BALANCING); } - if (new->flags & IRQF_NO_SOFTIRQ_CALL) - irq_settings_set_no_softirq_call(desc); - - if (irq_settings_can_autoenable(desc)) { + if (!(new->flags & IRQF_NO_AUTOEN) && + irq_settings_can_autoenable(desc)) { irq_startup(desc, IRQ_RESEND, IRQ_START_COND); } else { /* @@ -1565,14 +1716,8 @@ irq_setup_timings(desc, new); - /* - * Strictly no need to wake it up, but hung_task complains - * when no hard interrupt wakes the thread up. - */ - if (new->thread) - wake_up_process(new->thread); - if (new->secondary) - wake_up_process(new->secondary->thread); + wake_up_and_wait_for_irq_thread_ready(desc, new); + wake_up_and_wait_for_irq_thread_ready(desc, new->secondary); register_irq_proc(irq, desc); new->dir = NULL; @@ -1617,34 +1762,6 @@ module_put(desc->owner); return ret; } - -/** - * setup_irq - setup an interrupt - * @irq: Interrupt line to setup - * @act: irqaction for the interrupt - * - * Used to statically setup interrupts in the early boot process. - */ -int setup_irq(unsigned int irq, struct irqaction *act) -{ - int retval; - struct irq_desc *desc = irq_to_desc(irq); - - if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc))) - return -EINVAL; - - retval = irq_chip_pm_get(&desc->irq_data); - if (retval < 0) - return retval; - - retval = __setup_irq(irq, desc, act); - - if (retval) - irq_chip_pm_put(&desc->irq_data); - - return retval; -} -EXPORT_SYMBOL_GPL(setup_irq); /* * Internal function to unregister an irqaction - used to free @@ -1761,7 +1878,7 @@ /* Last action releases resources */ if (!desc->action) { /* - * Reaquire bus lock as irq_release_resources() might + * Reacquire bus lock as irq_release_resources() might * require it to deallocate resources over the slow bus. */ chip_bus_lock(desc); @@ -1785,22 +1902,6 @@ kfree(action->secondary); return action; } - -/** - * remove_irq - free an interrupt - * @irq: Interrupt line to free - * @act: irqaction for the interrupt - * - * Used to remove interrupts statically setup by the early boot process. - */ -void remove_irq(unsigned int irq, struct irqaction *act) -{ - struct irq_desc *desc = irq_to_desc(irq); - - if (desc && !WARN_ON(irq_settings_is_per_cpu_devid(desc))) - __free_irq(desc, act->dev_id); -} -EXPORT_SYMBOL_GPL(remove_irq); /** * free_irq - free an interrupt allocated with request_irq @@ -1842,6 +1943,59 @@ return devname; } EXPORT_SYMBOL(free_irq); + +/* This function must be called with desc->lock held */ +static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc) +{ + const char *devname = NULL; + + desc->istate &= ~IRQS_NMI; + + if (!WARN_ON(desc->action == NULL)) { + irq_pm_remove_action(desc, desc->action); + devname = desc->action->name; + unregister_handler_proc(irq, desc->action); + + kfree(desc->action); + desc->action = NULL; + } + + irq_settings_clr_disable_unlazy(desc); + irq_shutdown_and_deactivate(desc); + + irq_release_resources(desc); + + irq_chip_pm_put(&desc->irq_data); + module_put(desc->owner); + + return devname; +} + +const void *free_nmi(unsigned int irq, void *dev_id) +{ + struct irq_desc *desc = irq_to_desc(irq); + unsigned long flags; + const void *devname; + + if (!desc || WARN_ON(!(desc->istate & IRQS_NMI))) + return NULL; + + if (WARN_ON(irq_settings_is_per_cpu_devid(desc))) + return NULL; + + /* NMI still enabled */ + if (WARN_ON(desc->depth == 0)) + disable_nmi_nosync(irq); + + raw_spin_lock_irqsave(&desc->lock, flags); + + irq_nmi_teardown(desc); + devname = __cleanup_nmi(irq, desc); + + raw_spin_unlock_irqrestore(&desc->lock, flags); + + return devname; +} /** * request_threaded_irq - allocate an interrupt line @@ -1902,10 +2056,15 @@ * which interrupt is which (messes up the interrupt freeing * logic etc). * + * Also shared interrupts do not go well with disabling auto enable. + * The sharing interrupt might request it while it's still disabled + * and then wait for interrupts forever. + * * Also IRQF_COND_SUSPEND only makes sense for shared interrupts and * it cannot be set along with IRQF_NO_SUSPEND. */ if (((irqflags & IRQF_SHARED) && !dev_id) || + ((irqflags & IRQF_SHARED) && (irqflags & IRQF_NO_AUTOEN)) || (!(irqflags & IRQF_SHARED) && (irqflags & IRQF_COND_SUSPEND)) || ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND))) return -EINVAL; @@ -2012,6 +2171,102 @@ } EXPORT_SYMBOL_GPL(request_any_context_irq); +/** + * request_nmi - allocate an interrupt line for NMI delivery + * @irq: Interrupt line to allocate + * @handler: Function to be called when the IRQ occurs. + * Threaded handler for threaded interrupts. + * @irqflags: Interrupt type flags + * @name: An ascii name for the claiming device + * @dev_id: A cookie passed back to the handler function + * + * This call allocates interrupt resources and enables the + * interrupt line and IRQ handling. It sets up the IRQ line + * to be handled as an NMI. + * + * An interrupt line delivering NMIs cannot be shared and IRQ handling + * cannot be threaded. + * + * Interrupt lines requested for NMI delivering must produce per cpu + * interrupts and have auto enabling setting disabled. + * + * Dev_id must be globally unique. Normally the address of the + * device data structure is used as the cookie. Since the handler + * receives this value it makes sense to use it. + * + * If the interrupt line cannot be used to deliver NMIs, function + * will fail and return a negative value. + */ +int request_nmi(unsigned int irq, irq_handler_t handler, + unsigned long irqflags, const char *name, void *dev_id) +{ + struct irqaction *action; + struct irq_desc *desc; + unsigned long flags; + int retval; + + if (irq == IRQ_NOTCONNECTED) + return -ENOTCONN; + + /* NMI cannot be shared, used for Polling */ + if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL)) + return -EINVAL; + + if (!(irqflags & IRQF_PERCPU)) + return -EINVAL; + + if (!handler) + return -EINVAL; + + desc = irq_to_desc(irq); + + if (!desc || (irq_settings_can_autoenable(desc) && + !(irqflags & IRQF_NO_AUTOEN)) || + !irq_settings_can_request(desc) || + WARN_ON(irq_settings_is_per_cpu_devid(desc)) || + !irq_supports_nmi(desc)) + return -EINVAL; + + action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); + if (!action) + return -ENOMEM; + + action->handler = handler; + action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING; + action->name = name; + action->dev_id = dev_id; + + retval = irq_chip_pm_get(&desc->irq_data); + if (retval < 0) + goto err_out; + + retval = __setup_irq(irq, desc, action); + if (retval) + goto err_irq_setup; + + raw_spin_lock_irqsave(&desc->lock, flags); + + /* Setup NMI state */ + desc->istate |= IRQS_NMI; + retval = irq_nmi_setup(desc); + if (retval) { + __cleanup_nmi(irq, desc); + raw_spin_unlock_irqrestore(&desc->lock, flags); + return -EINVAL; + } + + raw_spin_unlock_irqrestore(&desc->lock, flags); + + return 0; + +err_irq_setup: + irq_chip_pm_put(&desc->irq_data); +err_out: + kfree(action); + + return retval; +} + void enable_percpu_irq(unsigned int irq, unsigned int type) { unsigned int cpu = smp_processor_id(); @@ -2045,6 +2300,11 @@ irq_put_desc_unlock(desc, flags); } EXPORT_SYMBOL_GPL(enable_percpu_irq); + +void enable_percpu_nmi(unsigned int irq, unsigned int type) +{ + enable_percpu_irq(irq, type); +} /** * irq_percpu_is_enabled - Check whether the per cpu irq is enabled @@ -2085,6 +2345,11 @@ } EXPORT_SYMBOL_GPL(disable_percpu_irq); +void disable_percpu_nmi(unsigned int irq) +{ + disable_percpu_irq(irq); +} + /* * Internal function to unregister a percpu irqaction. */ @@ -2115,6 +2380,8 @@ /* Found it - now remove it from the list of entries: */ desc->action = NULL; + + desc->istate &= ~IRQS_NMI; raw_spin_unlock_irqrestore(&desc->lock, flags); @@ -2168,6 +2435,19 @@ chip_bus_sync_unlock(desc); } EXPORT_SYMBOL_GPL(free_percpu_irq); + +void free_percpu_nmi(unsigned int irq, void __percpu *dev_id) +{ + struct irq_desc *desc = irq_to_desc(irq); + + if (!desc || !irq_settings_is_per_cpu_devid(desc)) + return; + + if (WARN_ON(!(desc->istate & IRQS_NMI))) + return; + + kfree(__free_percpu_irq(irq, dev_id)); +} /** * setup_percpu_irq - setup a per-cpu interrupt @@ -2258,6 +2538,158 @@ } EXPORT_SYMBOL_GPL(__request_percpu_irq); +/** + * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery + * @irq: Interrupt line to allocate + * @handler: Function to be called when the IRQ occurs. + * @name: An ascii name for the claiming device + * @dev_id: A percpu cookie passed back to the handler function + * + * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs + * have to be setup on each CPU by calling prepare_percpu_nmi() before + * being enabled on the same CPU by using enable_percpu_nmi(). + * + * Dev_id must be globally unique. It is a per-cpu variable, and + * the handler gets called with the interrupted CPU's instance of + * that variable. + * + * Interrupt lines requested for NMI delivering should have auto enabling + * setting disabled. + * + * If the interrupt line cannot be used to deliver NMIs, function + * will fail returning a negative value. + */ +int request_percpu_nmi(unsigned int irq, irq_handler_t handler, + const char *name, void __percpu *dev_id) +{ + struct irqaction *action; + struct irq_desc *desc; + unsigned long flags; + int retval; + + if (!handler) + return -EINVAL; + + desc = irq_to_desc(irq); + + if (!desc || !irq_settings_can_request(desc) || + !irq_settings_is_per_cpu_devid(desc) || + irq_settings_can_autoenable(desc) || + !irq_supports_nmi(desc)) + return -EINVAL; + + /* The line cannot already be NMI */ + if (desc->istate & IRQS_NMI) + return -EINVAL; + + action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); + if (!action) + return -ENOMEM; + + action->handler = handler; + action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD + | IRQF_NOBALANCING; + action->name = name; + action->percpu_dev_id = dev_id; + + retval = irq_chip_pm_get(&desc->irq_data); + if (retval < 0) + goto err_out; + + retval = __setup_irq(irq, desc, action); + if (retval) + goto err_irq_setup; + + raw_spin_lock_irqsave(&desc->lock, flags); + desc->istate |= IRQS_NMI; + raw_spin_unlock_irqrestore(&desc->lock, flags); + + return 0; + +err_irq_setup: + irq_chip_pm_put(&desc->irq_data); +err_out: + kfree(action); + + return retval; +} + +/** + * prepare_percpu_nmi - performs CPU local setup for NMI delivery + * @irq: Interrupt line to prepare for NMI delivery + * + * This call prepares an interrupt line to deliver NMI on the current CPU, + * before that interrupt line gets enabled with enable_percpu_nmi(). + * + * As a CPU local operation, this should be called from non-preemptible + * context. + * + * If the interrupt line cannot be used to deliver NMIs, function + * will fail returning a negative value. + */ +int prepare_percpu_nmi(unsigned int irq) +{ + unsigned long flags; + struct irq_desc *desc; + int ret = 0; + + WARN_ON(preemptible()); + + desc = irq_get_desc_lock(irq, &flags, + IRQ_GET_DESC_CHECK_PERCPU); + if (!desc) + return -EINVAL; + + if (WARN(!(desc->istate & IRQS_NMI), + KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n", + irq)) { + ret = -EINVAL; + goto out; + } + + ret = irq_nmi_setup(desc); + if (ret) { + pr_err("Failed to setup NMI delivery: irq %u\n", irq); + goto out; + } + +out: + irq_put_desc_unlock(desc, flags); + return ret; +} + +/** + * teardown_percpu_nmi - undoes NMI setup of IRQ line + * @irq: Interrupt line from which CPU local NMI configuration should be + * removed + * + * This call undoes the setup done by prepare_percpu_nmi(). + * + * IRQ line should not be enabled for the current CPU. + * + * As a CPU local operation, this should be called from non-preemptible + * context. + */ +void teardown_percpu_nmi(unsigned int irq) +{ + unsigned long flags; + struct irq_desc *desc; + + WARN_ON(preemptible()); + + desc = irq_get_desc_lock(irq, &flags, + IRQ_GET_DESC_CHECK_PERCPU); + if (!desc) + return; + + if (WARN_ON(!(desc->istate & IRQS_NMI))) + goto out; + + irq_nmi_teardown(desc); +out: + irq_put_desc_unlock(desc, flags); +} + int __irq_get_irqchip_state(struct irq_data *data, enum irqchip_irq_state which, bool *state) { @@ -2266,6 +2698,8 @@ do { chip = irq_data_get_irq_chip(data); + if (WARN_ON_ONCE(!chip)) + return -ENODEV; if (chip->irq_get_irqchip_state) break; #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY @@ -2323,7 +2757,7 @@ * This call sets the internal irqchip state of an interrupt, * depending on the value of @which. * - * This function should be called with migration disabled if the + * This function should be called with preemption disabled if the * interrupt controller has per-cpu registers. */ int irq_set_irqchip_state(unsigned int irq, enum irqchip_irq_state which, @@ -2343,6 +2777,10 @@ do { chip = irq_data_get_irq_chip(data); + if (WARN_ON_ONCE(!chip)) { + err = -ENODEV; + goto out_unlock; + } if (chip->irq_set_irqchip_state) break; #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY @@ -2355,6 +2793,7 @@ if (data) err = chip->irq_set_irqchip_state(data, which, val); +out_unlock: irq_put_desc_busunlock(desc, flags); return err; } -- Gitblit v1.6.2