// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 1992, 1998-2006 Linus Torvalds, Ingo Molnar * Copyright (C) 2005-2006 Thomas Gleixner * * This file contains driver APIs to the irq subsystem. */ #define pr_fmt(fmt) "genirq: " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include "internals.h" #if defined(CONFIG_IRQ_FORCED_THREADING) && !defined(CONFIG_PREEMPT_RT) __read_mostly bool force_irqthreads; EXPORT_SYMBOL_GPL(force_irqthreads); static int __init setup_forced_irqthreads(char *arg) { force_irqthreads = true; return 0; } early_param("threadirqs", setup_forced_irqthreads); #endif static void __synchronize_hardirq(struct irq_desc *desc, bool sync_chip) { struct irq_data *irqd = irq_desc_get_irq_data(desc); bool inprogress; do { unsigned long flags; /* * Wait until we're out of the critical section. This might * give the wrong answer due to the lack of memory barriers. */ while (irqd_irq_inprogress(&desc->irq_data)) cpu_relax(); /* Ok, that indicated we're done: double-check carefully. */ raw_spin_lock_irqsave(&desc->lock, flags); inprogress = irqd_irq_inprogress(&desc->irq_data); /* * If requested and supported, check at the chip whether it * is in flight at the hardware level, i.e. already pending * in a CPU and waiting for service and acknowledge. */ if (!inprogress && sync_chip) { /* * Ignore the return code. inprogress is only updated * when the chip supports it. */ __irq_get_irqchip_state(irqd, IRQCHIP_STATE_ACTIVE, &inprogress); } raw_spin_unlock_irqrestore(&desc->lock, flags); /* Oops, that failed? */ } while (inprogress); } /** * synchronize_hardirq - wait for pending hard IRQ handlers (on other CPUs) * @irq: interrupt number to wait for * * This function waits for any pending hard IRQ handlers for this * interrupt to complete before returning. If you use this * function while holding a resource the IRQ handler may need you * will deadlock. It does not take associated threaded handlers * into account. * * Do not use this for shutdown scenarios where you must be sure * that all parts (hardirq and threaded handler) have completed. * * Returns: false if a threaded handler is active. * * This function may be called - with care - from IRQ context. * * It does not check whether there is an interrupt in flight at the * hardware level, but not serviced yet, as this might deadlock when * called with interrupts disabled and the target CPU of the interrupt * is the current CPU. */ bool synchronize_hardirq(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); if (desc) { __synchronize_hardirq(desc, false); return !atomic_read(&desc->threads_active); } return true; } EXPORT_SYMBOL(synchronize_hardirq); /** * synchronize_irq - wait for pending IRQ handlers (on other CPUs) * @irq: interrupt number to wait for * * This function waits for any pending IRQ handlers for this interrupt * to complete before returning. If you use this function while * holding a resource the IRQ handler may need you will deadlock. * * Can only be called from preemptible code as it might sleep when * an interrupt thread is associated to @irq. * * It optionally makes sure (when the irq chip supports that method) * that the interrupt is not pending in any CPU and waiting for * service. */ void synchronize_irq(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); if (desc) { __synchronize_hardirq(desc, true); /* * We made sure that no hardirq handler is * running. Now verify that no threaded handlers are * active. */ wait_event(desc->wait_for_threads, !atomic_read(&desc->threads_active)); } } EXPORT_SYMBOL(synchronize_irq); #ifdef CONFIG_SMP cpumask_var_t irq_default_affinity; static bool __irq_can_set_affinity(struct irq_desc *desc) { if (!desc || !irqd_can_balance(&desc->irq_data) || !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity) return false; return true; } /** * irq_can_set_affinity - Check if the affinity of a given irq can be set * @irq: Interrupt to check * */ int irq_can_set_affinity(unsigned int irq) { return __irq_can_set_affinity(irq_to_desc(irq)); } /** * irq_can_set_affinity_usr - Check if affinity of a irq can be set from user space * @irq: Interrupt to check * * Like irq_can_set_affinity() above, but additionally checks for the * AFFINITY_MANAGED flag. */ bool irq_can_set_affinity_usr(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); return __irq_can_set_affinity(desc) && !irqd_affinity_is_managed(&desc->irq_data); } /** * irq_set_thread_affinity - Notify irq threads to adjust affinity * @desc: irq descriptor which has affitnity changed * * We just set IRQTF_AFFINITY and delegate the affinity setting * to the interrupt thread itself. We can not call * set_cpus_allowed_ptr() here as we hold desc->lock and this * code can be called from hard interrupt context. */ void irq_set_thread_affinity(struct irq_desc *desc) { struct irqaction *action; for_each_action_of_desc(desc, action) if (action->thread) set_bit(IRQTF_AFFINITY, &action->thread_flags); } #ifdef CONFIG_GENERIC_IRQ_EFFECTIVE_AFF_MASK static void irq_validate_effective_affinity(struct irq_data *data) { const struct cpumask *m = irq_data_get_effective_affinity_mask(data); struct irq_chip *chip = irq_data_get_irq_chip(data); if (!cpumask_empty(m)) return; pr_warn_once("irq_chip %s did not update eff. affinity mask of irq %u\n", chip->name, data->irq); } static inline void irq_init_effective_affinity(struct irq_data *data, const struct cpumask *mask) { cpumask_copy(irq_data_get_effective_affinity_mask(data), mask); } #else static inline void irq_validate_effective_affinity(struct irq_data *data) { } static inline void irq_init_effective_affinity(struct irq_data *data, const struct cpumask *mask) { } #endif int irq_do_set_affinity(struct irq_data *data, const struct cpumask *mask, bool force) { struct irq_desc *desc = irq_data_to_desc(data); struct irq_chip *chip = irq_data_get_irq_chip(data); int ret; if (!chip || !chip->irq_set_affinity) return -EINVAL; /* * 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, *prog_mask; static DEFINE_RAW_SPINLOCK(tmp_mask_lock); static struct cpumask tmp_mask; hk_mask = housekeeping_cpumask(HK_FLAG_MANAGED_IRQ); raw_spin_lock(&tmp_mask_lock); cpumask_and(&tmp_mask, mask, hk_mask); if (!cpumask_intersects(&tmp_mask, cpu_online_mask)) prog_mask = mask; else prog_mask = &tmp_mask; ret = chip->irq_set_affinity(data, prog_mask, force); raw_spin_unlock(&tmp_mask_lock); } else { ret = chip->irq_set_affinity(data, mask, force); } 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); ret = 0; } return ret; } #ifdef CONFIG_GENERIC_PENDING_IRQ static inline int irq_set_affinity_pending(struct irq_data *data, const struct cpumask *dest) { struct irq_desc *desc = irq_data_to_desc(data); irqd_set_move_pending(data); irq_copy_pending(desc, dest); return 0; } #else static inline int irq_set_affinity_pending(struct irq_data *data, const struct cpumask *dest) { return -EBUSY; } #endif static int irq_try_set_affinity(struct irq_data *data, const struct cpumask *dest, bool force) { int ret = irq_do_set_affinity(data, dest, force); /* * In case that the underlying vector management is busy and the * architecture supports the generic pending mechanism then utilize * this to avoid returning an error to user space. */ if (ret == -EBUSY && !force) ret = irq_set_affinity_pending(data, dest); return ret; } static bool irq_set_affinity_deactivated(struct irq_data *data, const struct cpumask *mask, bool force) { struct irq_desc *desc = irq_data_to_desc(data); /* * Handle irq chips which can handle affinity only in activated * state correctly * * 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. */ if (!IS_ENABLED(CONFIG_IRQ_DOMAIN_HIERARCHY) || irqd_is_activated(data) || !irqd_affinity_on_activate(data)) return false; cpumask_copy(desc->irq_common_data.affinity, mask); irq_init_effective_affinity(data, mask); irqd_set(data, IRQD_AFFINITY_SET); return true; } int irq_set_affinity_locked(struct irq_data *data, const struct cpumask *mask, bool force) { struct irq_chip *chip = irq_data_get_irq_chip(data); struct irq_desc *desc = irq_data_to_desc(data); int ret = 0; if (!chip || !chip->irq_set_affinity) return -EINVAL; if (irq_set_affinity_deactivated(data, mask, force)) return 0; if (irq_can_move_pcntxt(data) && !irqd_is_setaffinity_pending(data)) { ret = irq_try_set_affinity(data, mask, force); } else { irqd_set_move_pending(data); irq_copy_pending(desc, mask); } if (desc->affinity_notify) { kref_get(&desc->affinity_notify->kref); if (!schedule_work(&desc->affinity_notify->work)) { /* Work was already scheduled, drop our extra ref */ kref_put(&desc->affinity_notify->kref, desc->affinity_notify->release); } } irqd_set(data, IRQD_AFFINITY_SET); return ret; } int __irq_set_affinity(unsigned int irq, const struct cpumask *mask, bool force) { struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; int ret; if (!desc) return -EINVAL; raw_spin_lock_irqsave(&desc->lock, flags); ret = irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask, force); raw_spin_unlock_irqrestore(&desc->lock, flags); return ret; } int irq_set_affinity_hint(unsigned int irq, const struct cpumask *m) { unsigned long flags; struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); if (!desc) return -EINVAL; desc->affinity_hint = m; irq_put_desc_unlock(desc, flags); /* set the initial affinity to prevent every interrupt being on CPU0 */ if (m) __irq_set_affinity(irq, m, false); return 0; } EXPORT_SYMBOL_GPL(irq_set_affinity_hint); static void irq_affinity_notify(struct work_struct *work) { struct irq_affinity_notify *notify = container_of(work, struct irq_affinity_notify, work); struct irq_desc *desc = irq_to_desc(notify->irq); cpumask_var_t cpumask; unsigned long flags; if (!desc || !alloc_cpumask_var(&cpumask, GFP_KERNEL)) goto out; raw_spin_lock_irqsave(&desc->lock, flags); if (irq_move_pending(&desc->irq_data)) irq_get_pending(cpumask, desc); else cpumask_copy(cpumask, desc->irq_common_data.affinity); raw_spin_unlock_irqrestore(&desc->lock, flags); notify->notify(notify, cpumask); free_cpumask_var(cpumask); out: kref_put(¬ify->kref, notify->release); } /** * irq_set_affinity_notifier - control notification of IRQ affinity changes * @irq: Interrupt for which to enable/disable notification * @notify: Context for notification, or %NULL to disable * notification. Function pointers must be initialised; * the other fields will be initialised by this function. * * Must be called in process context. Notification may only be enabled * after the IRQ is allocated and must be disabled before the IRQ is * freed using free_irq(). */ int irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify) { struct irq_desc *desc = irq_to_desc(irq); struct irq_affinity_notify *old_notify; unsigned long flags; /* The release function is promised process context */ might_sleep(); if (!desc || desc->istate & IRQS_NMI) return -EINVAL; /* Complete initialisation of *notify */ if (notify) { notify->irq = irq; kref_init(¬ify->kref); INIT_WORK(¬ify->work, irq_affinity_notify); } raw_spin_lock_irqsave(&desc->lock, flags); old_notify = desc->affinity_notify; desc->affinity_notify = notify; raw_spin_unlock_irqrestore(&desc->lock, flags); if (old_notify) { if (cancel_work_sync(&old_notify->work)) { /* Pending work had a ref, put that one too */ kref_put(&old_notify->kref, old_notify->release); } kref_put(&old_notify->kref, old_notify->release); } return 0; } EXPORT_SYMBOL_GPL(irq_set_affinity_notifier); #ifndef CONFIG_AUTO_IRQ_AFFINITY /* * Generic version of the affinity autoselector. */ int irq_setup_affinity(struct irq_desc *desc) { struct cpumask *set = irq_default_affinity; int ret, node = irq_desc_get_node(desc); static DEFINE_RAW_SPINLOCK(mask_lock); static struct cpumask mask; /* Excludes PER_CPU and NO_BALANCE interrupts */ if (!__irq_can_set_affinity(desc)) return 0; raw_spin_lock(&mask_lock); /* * Preserve the managed affinity setting and a userspace affinity * setup, but make sure that one of the targets is online. */ if (irqd_affinity_is_managed(&desc->irq_data) || irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) { if (cpumask_intersects(desc->irq_common_data.affinity, cpu_online_mask)) set = desc->irq_common_data.affinity; else irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET); } cpumask_and(&mask, cpu_online_mask, set); if (cpumask_empty(&mask)) cpumask_copy(&mask, cpu_online_mask); if (node != NUMA_NO_NODE) { const struct cpumask *nodemask = cpumask_of_node(node); /* make sure at least one of the cpus in nodemask is online */ if (cpumask_intersects(&mask, nodemask)) cpumask_and(&mask, &mask, nodemask); } ret = irq_do_set_affinity(&desc->irq_data, &mask, false); raw_spin_unlock(&mask_lock); return ret; } #else /* Wrapper for ALPHA specific affinity selector magic */ int irq_setup_affinity(struct irq_desc *desc) { return irq_select_affinity(irq_desc_get_irq(desc)); } #endif /* CONFIG_AUTO_IRQ_AFFINITY */ #endif /* CONFIG_SMP */ /** * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt * @irq: interrupt number to set affinity * @vcpu_info: vCPU specific data or pointer to a percpu array of vCPU * specific data for percpu_devid interrupts * * This function uses the vCPU specific data to set the vCPU * affinity for an irq. The vCPU specific data is passed from * outside, such as KVM. One example code path is as below: * KVM -> IOMMU -> irq_set_vcpu_affinity(). */ int irq_set_vcpu_affinity(unsigned int irq, void *vcpu_info) { unsigned long flags; struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0); struct irq_data *data; struct irq_chip *chip; int ret = -ENOSYS; if (!desc) return -EINVAL; data = irq_desc_get_irq_data(desc); do { chip = irq_data_get_irq_chip(data); if (chip && chip->irq_set_vcpu_affinity) break; #ifdef CONFIG_IRQ_DOMAIN_HIERARCHY data = data->parent_data; #else data = NULL; #endif } while (data); if (data) ret = chip->irq_set_vcpu_affinity(data, vcpu_info); irq_put_desc_unlock(desc, flags); return ret; } EXPORT_SYMBOL_GPL(irq_set_vcpu_affinity); void __disable_irq(struct irq_desc *desc) { if (!desc->depth++) irq_disable(desc); } static int __disable_irq_nosync(unsigned int irq) { unsigned long flags; struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); if (!desc) return -EINVAL; __disable_irq(desc); irq_put_desc_busunlock(desc, flags); return 0; } /** * disable_irq_nosync - disable an irq without waiting * @irq: Interrupt to disable * * Disable the selected interrupt line. Disables and Enables are * nested. * Unlike disable_irq(), this function does not ensure existing * instances of the IRQ handler have completed before returning. * * This function may be called from IRQ context. */ void disable_irq_nosync(unsigned int irq) { __disable_irq_nosync(irq); } EXPORT_SYMBOL(disable_irq_nosync); /** * disable_irq - disable an irq and wait for completion * @irq: Interrupt to disable * * Disable the selected interrupt line. Enables and Disables are * nested. * This function waits for any pending IRQ handlers for this interrupt * to complete before returning. If you use this function while * holding a resource the IRQ handler may need you will deadlock. * * This function may be called - with care - from IRQ context. */ void disable_irq(unsigned int irq) { if (!__disable_irq_nosync(irq)) synchronize_irq(irq); } EXPORT_SYMBOL(disable_irq); /** * disable_hardirq - disables an irq and waits for hardirq completion * @irq: Interrupt to disable * * Disable the selected interrupt line. Enables and Disables are * nested. * This function waits for any pending hard IRQ handlers for this * interrupt to complete before returning. If you use this function while * holding a resource the hard IRQ handler may need you will deadlock. * * When used to optimistically disable an interrupt from atomic context * the return value must be checked. * * Returns: false if a threaded handler is active. * * This function may be called - with care - from IRQ context. */ bool disable_hardirq(unsigned int irq) { if (!__disable_irq_nosync(irq)) return synchronize_hardirq(irq); return false; } 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) { case 0: err_out: WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq_desc_get_irq(desc)); break; case 1: { if (desc->istate & IRQS_SUSPENDED) goto err_out; /* Prevent probing on this irq: */ irq_settings_set_noprobe(desc); /* * Call irq_startup() not irq_enable() here because the * interrupt might be marked NOAUTOEN. So irq_startup() * needs to be invoked when it gets enabled the first * time. If it was already started up, then irq_startup() * will invoke irq_enable() under the hood. */ irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE); break; } default: desc->depth--; } } /** * enable_irq - enable handling of an irq * @irq: Interrupt to enable * * Undoes the effect of one call to disable_irq(). If this * matches the last disable, processing of interrupts on this * IRQ line is re-enabled. * * This function may be called from IRQ context only when * desc->irq_data.chip->bus_lock and desc->chip->bus_sync_unlock are NULL ! */ void enable_irq(unsigned int irq) { unsigned long flags; struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); if (!desc) return; if (WARN(!desc->irq_data.chip, KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq)) goto out; __enable_irq(desc); out: irq_put_desc_busunlock(desc, flags); } 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); int ret = -ENXIO; if (irq_desc_get_chip(desc)->flags & IRQCHIP_SKIP_SET_WAKE) return 0; if (desc->irq_data.chip->irq_set_wake) ret = desc->irq_data.chip->irq_set_wake(&desc->irq_data, on); return ret; } /** * irq_set_irq_wake - control irq power management wakeup * @irq: interrupt to control * @on: enable/disable power management wakeup * * Enable/disable power management wakeup mode, which is * disabled by default. Enables and disables must match, * just as they match for non-wakeup mode support. * * 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) { unsigned long flags; struct irq_desc *desc = irq_get_desc_buslock(irq, &flags, IRQ_GET_DESC_CHECK_GLOBAL); int ret = 0; 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. */ if (on) { if (desc->wake_depth++ == 0) { ret = set_irq_wake_real(irq, on); if (ret) desc->wake_depth = 0; else irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE); } } else { if (desc->wake_depth == 0) { WARN(1, "Unbalanced IRQ %d wake disable\n", irq); } else if (--desc->wake_depth == 0) { ret = set_irq_wake_real(irq, on); if (ret) desc->wake_depth = 1; else irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE); } } out_unlock: irq_put_desc_busunlock(desc, flags); return ret; } EXPORT_SYMBOL(irq_set_irq_wake); /* * Internal function that tells the architecture code whether a * particular irq has been exclusively allocated or is available * for driver use. */ int can_request_irq(unsigned int irq, unsigned long irqflags) { unsigned long flags; struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0); int canrequest = 0; if (!desc) return 0; if (irq_settings_can_request(desc)) { if (!desc->action || irqflags & desc->action->flags & IRQF_SHARED) canrequest = 1; } irq_put_desc_unlock(desc, flags); return canrequest; } int __irq_set_trigger(struct irq_desc *desc, unsigned long flags) { struct irq_chip *chip = desc->irq_data.chip; int ret, unmask = 0; if (!chip || !chip->irq_set_type) { /* * IRQF_TRIGGER_* but the PIC does not support multiple * flow-types? */ pr_debug("No set_type function for IRQ %d (%s)\n", irq_desc_get_irq(desc), chip ? (chip->name ? : "unknown") : "unknown"); return 0; } if (chip->flags & IRQCHIP_SET_TYPE_MASKED) { if (!irqd_irq_masked(&desc->irq_data)) mask_irq(desc); if (!irqd_irq_disabled(&desc->irq_data)) unmask = 1; } /* Mask all flags except trigger mode */ flags &= IRQ_TYPE_SENSE_MASK; ret = chip->irq_set_type(&desc->irq_data, flags); switch (ret) { case IRQ_SET_MASK_OK: 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); irq_settings_set_trigger_mask(desc, flags); irqd_clear(&desc->irq_data, IRQD_LEVEL); irq_settings_clr_level(desc); if (flags & IRQ_TYPE_LEVEL_MASK) { irq_settings_set_level(desc); irqd_set(&desc->irq_data, IRQD_LEVEL); } ret = 0; break; default: pr_err("Setting trigger mode %lu for irq %u failed (%pS)\n", flags, irq_desc_get_irq(desc), chip->irq_set_type); } if (unmask) unmask_irq(desc); return ret; } #ifdef CONFIG_HARDIRQS_SW_RESEND int irq_set_parent(int irq, int parent_irq) { unsigned long flags; struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0); if (!desc) return -EINVAL; desc->parent_irq = parent_irq; irq_put_desc_unlock(desc, flags); return 0; } EXPORT_SYMBOL_GPL(irq_set_parent); #endif /* * Default primary interrupt handler for threaded interrupts. Is * assigned as primary handler when request_threaded_irq is called * with handler == NULL. Useful for oneshot interrupts. */ static irqreturn_t irq_default_primary_handler(int irq, void *dev_id) { return IRQ_WAKE_THREAD; } /* * Primary handler for nested threaded interrupts. Should never be * called. */ static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id) { WARN(1, "Primary handler called for nested irq %d\n", irq); return IRQ_NONE; } static irqreturn_t irq_forced_secondary_handler(int irq, void *dev_id) { WARN(1, "Secondary action handler called for irq %d\n", irq); return IRQ_NONE; } static int irq_wait_for_interrupt(struct irqaction *action) { for (;;) { set_current_state(TASK_INTERRUPTIBLE); if (kthread_should_stop()) { /* may need to run one last time */ if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags)) { __set_current_state(TASK_RUNNING); return 0; } __set_current_state(TASK_RUNNING); return -1; } if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags)) { __set_current_state(TASK_RUNNING); return 0; } schedule(); } } /* * Oneshot interrupts keep the irq line masked until the threaded * handler finished. unmask if the interrupt has not been disabled and * is marked MASKED. */ static void irq_finalize_oneshot(struct irq_desc *desc, struct irqaction *action) { if (!(desc->istate & IRQS_ONESHOT) || action->handler == irq_forced_secondary_handler) return; again: chip_bus_lock(desc); raw_spin_lock_irq(&desc->lock); /* * Implausible though it may be we need to protect us against * the following scenario: * * The thread is faster done than the hard interrupt handler * on the other CPU. If we unmask the irq line then the * interrupt can come in again and masks the line, leaves due * 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 * irq_wake_thread(). See the comment there which explains the * serialization. */ if (unlikely(irqd_irq_inprogress(&desc->irq_data))) { raw_spin_unlock_irq(&desc->lock); chip_bus_sync_unlock(desc); cpu_relax(); goto again; } /* * Now check again, whether the thread should run. Otherwise * we would clear the threads_oneshot bit of this thread which * was just set. */ if (test_bit(IRQTF_RUNTHREAD, &action->thread_flags)) goto out_unlock; desc->threads_oneshot &= ~action->thread_mask; if (!desc->threads_oneshot && !irqd_irq_disabled(&desc->irq_data) && irqd_irq_masked(&desc->irq_data)) unmask_threaded_irq(desc); out_unlock: raw_spin_unlock_irq(&desc->lock); chip_bus_sync_unlock(desc); } #ifdef CONFIG_SMP /* * Check whether we need to change the affinity of the interrupt thread. */ static void irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { cpumask_var_t mask; bool valid = true; if (!test_and_clear_bit(IRQTF_AFFINITY, &action->thread_flags)) return; /* * In case we are out of memory we set IRQTF_AFFINITY again and * try again next time */ if (!alloc_cpumask_var(&mask, GFP_KERNEL)) { set_bit(IRQTF_AFFINITY, &action->thread_flags); return; } raw_spin_lock_irq(&desc->lock); /* * This code is triggered unconditionally. Check the affinity * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out. */ if (cpumask_available(desc->irq_common_data.affinity)) { const struct cpumask *m; m = irq_data_get_effective_affinity_mask(&desc->irq_data); cpumask_copy(mask, m); } else { valid = false; } raw_spin_unlock_irq(&desc->lock); if (valid) set_cpus_allowed_ptr(current, mask); free_cpumask_var(mask); } #else static inline void irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { } #endif /* * 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. */ static irqreturn_t irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action) { irqreturn_t ret; local_bh_disable(); 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)) local_irq_enable(); local_bh_enable(); return ret; } /* * Interrupts explicitly requested as threaded interrupts want to be * preemtible - many of them need to sleep and wait for slow busses to * complete. */ static irqreturn_t irq_thread_fn(struct irq_desc *desc, struct irqaction *action) { irqreturn_t ret; ret = action->thread_fn(action->irq, action->dev_id); if (ret == IRQ_HANDLED) atomic_inc(&desc->threads_handled); irq_finalize_oneshot(desc, action); return ret; } static void wake_threads_waitq(struct irq_desc *desc) { if (atomic_dec_and_test(&desc->threads_active)) wake_up(&desc->wait_for_threads); } static void irq_thread_dtor(struct callback_head *unused) { struct task_struct *tsk = current; struct irq_desc *desc; struct irqaction *action; if (WARN_ON_ONCE(!(current->flags & PF_EXITING))) return; action = kthread_data(tsk); pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n", tsk->comm, tsk->pid, action->irq); desc = irq_to_desc(action->irq); /* * If IRQTF_RUNTHREAD is set, we need to decrement * desc->threads_active and wake possible waiters. */ if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags)) wake_threads_waitq(desc); /* Prevent a stale desc->threads_oneshot */ irq_finalize_oneshot(desc, action); } static void irq_wake_secondary(struct irq_desc *desc, struct irqaction *action) { struct irqaction *secondary = action->secondary; if (WARN_ON_ONCE(!secondary)) return; raw_spin_lock_irq(&desc->lock); __irq_wake_thread(desc, secondary); raw_spin_unlock_irq(&desc->lock); } /* * Interrupt handler thread */ static int irq_thread(void *data) { struct callback_head on_exit_work; struct irqaction *action = data; struct irq_desc *desc = irq_to_desc(action->irq); irqreturn_t (*handler_fn)(struct irq_desc *desc, struct irqaction *action); if (force_irqthreads && test_bit(IRQTF_FORCED_THREAD, &action->thread_flags)) handler_fn = irq_forced_thread_fn; else handler_fn = irq_thread_fn; init_task_work(&on_exit_work, irq_thread_dtor); task_work_add(current, &on_exit_work, TWA_NONE); irq_thread_check_affinity(desc, action); while (!irq_wait_for_interrupt(action)) { irqreturn_t action_ret; irq_thread_check_affinity(desc, action); action_ret = handler_fn(desc, action); if (action_ret == IRQ_WAKE_THREAD) irq_wake_secondary(desc, action); wake_threads_waitq(desc); } /* * This is the regular exit path. __free_irq() is stopping the * thread via kthread_stop() after calling * synchronize_hardirq(). So neither IRQTF_RUNTHREAD nor the * oneshot mask bit can be set. */ task_work_cancel(current, irq_thread_dtor); return 0; } /** * irq_wake_thread - wake the irq thread for the action identified by dev_id * @irq: Interrupt line * @dev_id: Device identity for which the thread should be woken * */ void irq_wake_thread(unsigned int irq, void *dev_id) { struct irq_desc *desc = irq_to_desc(irq); struct irqaction *action; unsigned long flags; if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc))) return; raw_spin_lock_irqsave(&desc->lock, flags); for_each_action_of_desc(desc, action) { if (action->dev_id == dev_id) { if (action->thread) __irq_wake_thread(desc, action); break; } } raw_spin_unlock_irqrestore(&desc->lock, flags); } EXPORT_SYMBOL_GPL(irq_wake_thread); static int irq_setup_forced_threading(struct irqaction *new) { if (!force_irqthreads) return 0; if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT)) return 0; /* * No further action required for interrupts which are requested as * threaded interrupts already */ if (new->handler == irq_default_primary_handler) return 0; new->flags |= IRQF_ONESHOT; /* * Handle the case where we have a real primary handler and a * thread handler. We force thread them as well by creating a * secondary action. */ if (new->handler && new->thread_fn) { /* Allocate the secondary action */ new->secondary = kzalloc(sizeof(struct irqaction), GFP_KERNEL); if (!new->secondary) return -ENOMEM; new->secondary->handler = irq_forced_secondary_handler; new->secondary->thread_fn = new->thread_fn; new->secondary->dev_id = new->dev_id; new->secondary->irq = new->irq; new->secondary->name = new->name; } /* Deal with the primary handler */ set_bit(IRQTF_FORCED_THREAD, &new->thread_flags); new->thread_fn = new->handler; new->handler = irq_default_primary_handler; return 0; } static int irq_request_resources(struct irq_desc *desc) { struct irq_data *d = &desc->irq_data; struct irq_chip *c = d->chip; return c->irq_request_resources ? c->irq_request_resources(d) : 0; } static void irq_release_resources(struct irq_desc *desc) { struct irq_data *d = &desc->irq_data; struct irq_chip *c = d->chip; if (c->irq_release_resources) 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; if (!secondary) { t = kthread_create(irq_thread, new, "irq/%d-%s", irq, new->name); } else { t = kthread_create(irq_thread, new, "irq/%d-s-%s", irq, new->name); } if (IS_ERR(t)) return PTR_ERR(t); 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. */ new->thread = get_task_struct(t); /* * Tell the thread to set its affinity. This is * important for shared interrupt handlers as we do * not invoke setup_affinity() for the secondary * handlers as everything is already set up. Even for * interrupts marked with IRQF_NO_BALANCE this is * correct as we want the thread to move to the cpu(s) * on which the requesting code placed the interrupt. */ set_bit(IRQTF_AFFINITY, &new->thread_flags); return 0; } /* * Internal function to register an irqaction - typically used to * allocate special interrupts that are part of the architecture. * * Locking rules: * * desc->request_mutex Provides serialization against a concurrent free_irq() * chip_bus_lock Provides serialization for slow bus operations * desc->lock Provides serialization against hard interrupts * * chip_bus_lock and desc->lock are sufficient for all other management and * interrupt related functions. desc->request_mutex solely serializes * request/free_irq(). */ static int __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) { struct irqaction *old, **old_ptr; unsigned long flags, thread_mask = 0; int ret, nested, shared = 0; if (!desc) return -EINVAL; if (desc->irq_data.chip == &no_irq_chip) return -ENOSYS; if (!try_module_get(desc->owner)) return -ENODEV; new->irq = irq; /* * If the trigger type is not specified by the caller, * then use the default for this interrupt. */ if (!(new->flags & IRQF_TRIGGER_MASK)) new->flags |= irqd_get_trigger_type(&desc->irq_data); /* * Check whether the interrupt nests into another interrupt * thread. */ nested = irq_settings_is_nested_thread(desc); if (nested) { if (!new->thread_fn) { ret = -EINVAL; goto out_mput; } /* * Replace the primary handler which was provided from * the driver for non nested interrupt handling by the * dummy function which warns when called. */ new->handler = irq_nested_primary_handler; } else { if (irq_settings_can_thread(desc)) { ret = irq_setup_forced_threading(new); if (ret) goto out_mput; } } /* * Create a handler thread when a thread function is supplied * and the interrupt does not nest into another interrupt * thread. */ if (new->thread_fn && !nested) { ret = setup_irq_thread(new, irq, false); if (ret) goto out_mput; if (new->secondary) { ret = setup_irq_thread(new->secondary, irq, true); if (ret) goto out_thread; } } /* * Drivers are often written to work w/o knowledge about the * underlying irq chip implementation, so a request for a * threaded irq without a primary hard irq context handler * requires the ONESHOT flag to be set. Some irq chips like * MSI based interrupts are per se one shot safe. Check the * chip flags, so we can avoid the unmask dance at the end of * the threaded handler for those. */ if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE) new->flags &= ~IRQF_ONESHOT; /* * Protects against a concurrent __free_irq() call which might wait * for synchronize_hardirq() to complete without holding the optional * chip bus lock and desc->lock. Also protects against handing out * a recycled oneshot thread_mask bit while it's still in use by * its previous owner. */ mutex_lock(&desc->request_mutex); /* * Acquire bus lock as the irq_request_resources() callback below * might rely on the serialization or the magic power management * functions which are abusing the irq_bus_lock() callback, */ chip_bus_lock(desc); /* First installed action requests resources. */ if (!desc->action) { ret = irq_request_resources(desc); if (ret) { pr_err("Failed to request resources for %s (irq %d) on irqchip %s\n", new->name, irq, desc->irq_data.chip->name); goto out_bus_unlock; } } /* * The following block of code has to be executed atomically * protected against a concurrent interrupt and any of the other * management calls which are not serialized via * desc->request_mutex or the optional bus lock. */ raw_spin_lock_irqsave(&desc->lock, flags); old_ptr = &desc->action; old = *old_ptr; if (old) { /* * Can't share interrupts unless both agree to and are * the same type (level, edge, polarity). So both flag * 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 * the one provided by the requester. */ if (irqd_trigger_type_was_set(&desc->irq_data)) { oldtype = irqd_get_trigger_type(&desc->irq_data); } else { oldtype = new->flags & IRQF_TRIGGER_MASK; irqd_set_trigger_type(&desc->irq_data, oldtype); } if (!((old->flags & new->flags) & IRQF_SHARED) || (oldtype != (new->flags & IRQF_TRIGGER_MASK)) || ((old->flags ^ new->flags) & IRQF_ONESHOT)) goto mismatch; /* All handlers must agree on per-cpuness */ if ((old->flags & IRQF_PERCPU) != (new->flags & IRQF_PERCPU)) goto mismatch; /* add new interrupt at end of irq queue */ do { /* * Or all existing action->thread_mask bits, * so we can find the next zero bit for this * new action. */ thread_mask |= old->thread_mask; old_ptr = &old->next; old = *old_ptr; } while (old); shared = 1; } /* * Setup the thread mask for this irqaction for ONESHOT. For * !ONESHOT irqs the thread mask is 0 so we can avoid a * conditional in irq_wake_thread(). */ if (new->flags & IRQF_ONESHOT) { /* * Unlikely to have 32 resp 64 irqs sharing one line, * but who knows. */ if (thread_mask == ~0UL) { ret = -EBUSY; goto out_unlock; } /* * The thread_mask for the action is or'ed to * desc->thread_active to indicate that the * IRQF_ONESHOT thread handler has been woken, but not * yet finished. The bit is cleared when a thread * completes. When all threads of a shared interrupt * line have completed desc->threads_active becomes * zero and the interrupt line is unmasked. See * handle.c:irq_wake_thread() for further information. * * If no thread is woken by primary (hard irq context) * interrupt handlers, then desc->threads_active is * also checked for zero to unmask the irq line in the * affected hard irq flow handlers * (handle_[fasteoi|level]_irq). * * The new action gets the first zero bit of * thread_mask assigned. See the loop above which or's * all existing action->thread_mask bits. */ new->thread_mask = 1UL << ffz(thread_mask); } else if (new->handler == irq_default_primary_handler && !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) { /* * The interrupt was requested with handler = NULL, so * we use the default primary handler for it. But it * does not have the oneshot flag set. In combination * with level interrupts this is deadly, because the * default primary handler just wakes the thread, then * the irq lines is reenabled, but the device still * has the level irq asserted. Rinse and repeat.... * * While this works for edge type interrupts, we play * it safe and reject unconditionally because we can't * say for sure which type this interrupt really * 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 %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, new->flags & IRQF_TRIGGER_MASK); if (ret) goto out_unlock; } /* * Activate the interrupt. That activation must happen * independently of IRQ_NOAUTOEN. request_irq() can fail * and the callers are supposed to handle * that. enable_irq() of an interrupt requested with * IRQ_NOAUTOEN is not supposed to fail. The activation * keeps it in shutdown mode, it merily associates * resources if necessary and if that's not possible it * fails. Interrupts which are in managed shutdown mode * will simply ignore that activation request. */ ret = irq_activate(desc); if (ret) goto out_unlock; desc->istate &= ~(IRQS_AUTODETECT | IRQS_SPURIOUS_DISABLED | \ IRQS_ONESHOT | IRQS_WAITING); irqd_clear(&desc->irq_data, IRQD_IRQ_INPROGRESS); if (new->flags & IRQF_PERCPU) { irqd_set(&desc->irq_data, IRQD_PER_CPU); irq_settings_set_per_cpu(desc); } if (new->flags & IRQF_ONESHOT) desc->istate |= IRQS_ONESHOT; /* Exclude IRQ from balancing if requested */ if (new->flags & IRQF_NOBALANCING) { irq_settings_set_no_balancing(desc); irqd_set(&desc->irq_data, IRQD_NO_BALANCING); } if (irq_settings_can_autoenable(desc)) { irq_startup(desc, IRQ_RESEND, IRQ_START_COND); } else { /* * 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. */ WARN_ON_ONCE(new->flags & IRQF_SHARED); /* Undo nested disables: */ desc->depth = 1; } } else if (new->flags & IRQF_TRIGGER_MASK) { unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK; unsigned int omsk = irqd_get_trigger_type(&desc->irq_data); if (nmsk != omsk) /* hope the handler works with current trigger mode */ pr_warn("irq %d uses trigger mode %u; requested %u\n", irq, omsk, nmsk); } *old_ptr = new; irq_pm_install_action(desc, new); /* Reset broken irq detection when installing new handler */ desc->irq_count = 0; desc->irqs_unhandled = 0; /* * Check whether we disabled the irq via the spurious handler * before. Reenable it and give it another chance. */ if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) { desc->istate &= ~IRQS_SPURIOUS_DISABLED; __enable_irq(desc); } raw_spin_unlock_irqrestore(&desc->lock, flags); chip_bus_sync_unlock(desc); mutex_unlock(&desc->request_mutex); 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); register_irq_proc(irq, desc); new->dir = NULL; register_handler_proc(irq, new); return 0; mismatch: if (!(new->flags & IRQF_PROBE_SHARED)) { pr_err("Flags mismatch irq %d. %08x (%s) vs. %08x (%s)\n", irq, new->flags, new->name, old->flags, old->name); #ifdef CONFIG_DEBUG_SHIRQ dump_stack(); #endif } ret = -EBUSY; out_unlock: raw_spin_unlock_irqrestore(&desc->lock, flags); if (!desc->action) irq_release_resources(desc); out_bus_unlock: chip_bus_sync_unlock(desc); mutex_unlock(&desc->request_mutex); out_thread: if (new->thread) { struct task_struct *t = new->thread; new->thread = NULL; kthread_stop(t); put_task_struct(t); } if (new->secondary && new->secondary->thread) { struct task_struct *t = new->secondary->thread; new->secondary->thread = NULL; kthread_stop(t); put_task_struct(t); } out_mput: module_put(desc->owner); return ret; } /* * Internal function to unregister an irqaction - used to free * regular and special interrupts that are part of the architecture. */ static struct irqaction *__free_irq(struct irq_desc *desc, void *dev_id) { unsigned irq = desc->irq_data.irq; struct irqaction *action, **action_ptr; unsigned long flags; WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); mutex_lock(&desc->request_mutex); chip_bus_lock(desc); raw_spin_lock_irqsave(&desc->lock, flags); /* * There can be multiple actions per IRQ descriptor, find the right * one based on the dev_id: */ action_ptr = &desc->action; for (;;) { action = *action_ptr; if (!action) { WARN(1, "Trying to free already-free IRQ %d\n", irq); raw_spin_unlock_irqrestore(&desc->lock, flags); chip_bus_sync_unlock(desc); mutex_unlock(&desc->request_mutex); return NULL; } if (action->dev_id == dev_id) break; action_ptr = &action->next; } /* Found it - now remove it from the list of entries: */ *action_ptr = action->next; irq_pm_remove_action(desc, action); /* If this was the last handler, shut down the IRQ line: */ if (!desc->action) { irq_settings_clr_disable_unlazy(desc); /* Only shutdown. Deactivate after synchronize_hardirq() */ irq_shutdown(desc); } #ifdef CONFIG_SMP /* make sure affinity_hint is cleaned up */ if (WARN_ON_ONCE(desc->affinity_hint)) desc->affinity_hint = NULL; #endif raw_spin_unlock_irqrestore(&desc->lock, flags); /* * Drop bus_lock here so the changes which were done in the chip * callbacks above are synced out to the irq chips which hang * behind a slow bus (I2C, SPI) before calling synchronize_hardirq(). * * Aside of that the bus_lock can also be taken from the threaded * handler in irq_finalize_oneshot() which results in a deadlock * because kthread_stop() would wait forever for the thread to * complete, which is blocked on the bus lock. * * The still held desc->request_mutex() protects against a * concurrent request_irq() of this irq so the release of resources * and timing data is properly serialized. */ chip_bus_sync_unlock(desc); unregister_handler_proc(irq, action); /* * Make sure it's not being used on another CPU and if the chip * supports it also make sure that there is no (not yet serviced) * interrupt in flight at the hardware level. */ __synchronize_hardirq(desc, true); #ifdef CONFIG_DEBUG_SHIRQ /* * It's a shared IRQ -- the driver ought to be prepared for an IRQ * event to happen even now it's being freed, so let's make sure that * is so by doing an extra call to the handler .... * * ( We do this after actually deregistering it, to make sure that a * 'real' IRQ doesn't run in parallel with our fake. ) */ if (action->flags & IRQF_SHARED) { local_irq_save(flags); action->handler(irq, dev_id); local_irq_restore(flags); } #endif /* * The action has already been removed above, but the thread writes * its oneshot mask bit when it completes. Though request_mutex is * held across this which prevents __setup_irq() from handing out * the same bit to a newly requested action. */ if (action->thread) { kthread_stop(action->thread); put_task_struct(action->thread); if (action->secondary && action->secondary->thread) { kthread_stop(action->secondary->thread); put_task_struct(action->secondary->thread); } } /* Last action releases resources */ if (!desc->action) { /* * Reaquire bus lock as irq_release_resources() might * require it to deallocate resources over the slow bus. */ chip_bus_lock(desc); /* * There is no interrupt on the fly anymore. Deactivate it * completely. */ raw_spin_lock_irqsave(&desc->lock, flags); irq_domain_deactivate_irq(&desc->irq_data); raw_spin_unlock_irqrestore(&desc->lock, flags); irq_release_resources(desc); chip_bus_sync_unlock(desc); irq_remove_timings(desc); } mutex_unlock(&desc->request_mutex); irq_chip_pm_put(&desc->irq_data); module_put(desc->owner); kfree(action->secondary); return action; } /** * free_irq - free an interrupt allocated with request_irq * @irq: Interrupt line to free * @dev_id: Device identity to free * * Remove an interrupt handler. The handler is removed and if the * interrupt line is no longer in use by any driver it is disabled. * On a shared IRQ the caller must ensure the interrupt is disabled * on the card it drives before calling this function. The function * does not return until any executing interrupts for this IRQ * have completed. * * This function must not be called from interrupt context. * * Returns the devname argument passed to request_irq. */ const void *free_irq(unsigned int irq, void *dev_id) { struct irq_desc *desc = irq_to_desc(irq); struct irqaction *action; const char *devname; if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc))) return NULL; #ifdef CONFIG_SMP if (WARN_ON(desc->affinity_notify)) desc->affinity_notify = NULL; #endif action = __free_irq(desc, dev_id); if (!action) return NULL; devname = action->name; kfree(action); 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 * @irq: Interrupt line to allocate * @handler: Function to be called when the IRQ occurs. * Primary handler for threaded interrupts * If NULL and thread_fn != NULL the default * primary handler is installed * @thread_fn: Function called from the irq handler thread * If NULL, no irq thread is created * @irqflags: Interrupt type flags * @devname: 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. From the point this * call is made your handler function may be invoked. Since * your handler function must clear any interrupt the board * raises, you must take care both to initialise your hardware * and to set up the interrupt handler in the right order. * * If you want to set up a threaded irq handler for your device * then you need to supply @handler and @thread_fn. @handler is * still called in hard interrupt context and has to check * whether the interrupt originates from the device. If yes it * needs to disable the interrupt on the device and return * IRQ_WAKE_THREAD which will wake up the handler thread and run * @thread_fn. This split handler design is necessary to support * shared interrupts. * * 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 your interrupt is shared you must pass a non NULL dev_id * as this is required when freeing the interrupt. * * Flags: * * IRQF_SHARED Interrupt is shared * IRQF_TRIGGER_* Specify active edge(s) or level * */ int request_threaded_irq(unsigned int irq, irq_handler_t handler, irq_handler_t thread_fn, unsigned long irqflags, const char *devname, void *dev_id) { struct irqaction *action; struct irq_desc *desc; int retval; if (irq == IRQ_NOTCONNECTED) return -ENOTCONN; /* * Sanity-check: shared interrupts must pass in a real dev-ID, * otherwise we'll have trouble later trying to figure out * which interrupt is which (messes up the interrupt freeing * logic etc). * * 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_COND_SUSPEND)) || ((irqflags & IRQF_NO_SUSPEND) && (irqflags & IRQF_COND_SUSPEND))) return -EINVAL; desc = irq_to_desc(irq); if (!desc) return -EINVAL; if (!irq_settings_can_request(desc) || WARN_ON(irq_settings_is_per_cpu_devid(desc))) return -EINVAL; if (!handler) { if (!thread_fn) return -EINVAL; handler = irq_default_primary_handler; } action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); if (!action) return -ENOMEM; action->handler = handler; action->thread_fn = thread_fn; action->flags = irqflags; action->name = devname; action->dev_id = dev_id; retval = irq_chip_pm_get(&desc->irq_data); if (retval < 0) { kfree(action); return retval; } retval = __setup_irq(irq, desc, action); if (retval) { irq_chip_pm_put(&desc->irq_data); kfree(action->secondary); kfree(action); } #ifdef CONFIG_DEBUG_SHIRQ_FIXME if (!retval && (irqflags & IRQF_SHARED)) { /* * It's a shared IRQ -- the driver ought to be prepared for it * to happen immediately, so let's make sure.... * We disable the irq to make sure that a 'real' IRQ doesn't * run in parallel with our fake. */ unsigned long flags; disable_irq(irq); local_irq_save(flags); handler(irq, dev_id); local_irq_restore(flags); enable_irq(irq); } #endif return retval; } EXPORT_SYMBOL(request_threaded_irq); /** * request_any_context_irq - allocate an interrupt line * @irq: Interrupt line to allocate * @handler: Function to be called when the IRQ occurs. * Threaded handler for threaded interrupts. * @flags: 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 selects either a * hardirq or threaded handling method depending on the * context. * * On failure, it returns a negative value. On success, * it returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED. */ int request_any_context_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, const char *name, void *dev_id) { struct irq_desc *desc; int ret; if (irq == IRQ_NOTCONNECTED) return -ENOTCONN; desc = irq_to_desc(irq); if (!desc) return -EINVAL; if (irq_settings_is_nested_thread(desc)) { ret = request_threaded_irq(irq, NULL, handler, flags, name, dev_id); return !ret ? IRQC_IS_NESTED : ret; } ret = request_irq(irq, handler, flags, name, dev_id); return !ret ? IRQC_IS_HARDIRQ : ret; } 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) || !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(); unsigned long flags; struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU); if (!desc) return; /* * If the trigger type is not specified by the caller, then * use the default for this interrupt. */ type &= IRQ_TYPE_SENSE_MASK; if (type == IRQ_TYPE_NONE) type = irqd_get_trigger_type(&desc->irq_data); if (type != IRQ_TYPE_NONE) { int ret; ret = __irq_set_trigger(desc, type); if (ret) { WARN(1, "failed to set type for IRQ%d\n", irq); goto out; } } irq_percpu_enable(desc, cpu); out: 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 * @irq: Linux irq number to check for * * Must be called from a non migratable context. Returns the enable * state of a per cpu interrupt on the current cpu. */ bool irq_percpu_is_enabled(unsigned int irq) { unsigned int cpu = smp_processor_id(); struct irq_desc *desc; unsigned long flags; bool is_enabled; desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU); if (!desc) return false; is_enabled = cpumask_test_cpu(cpu, desc->percpu_enabled); irq_put_desc_unlock(desc, flags); return is_enabled; } EXPORT_SYMBOL_GPL(irq_percpu_is_enabled); void disable_percpu_irq(unsigned int irq) { unsigned int cpu = smp_processor_id(); unsigned long flags; struct irq_desc *desc = irq_get_desc_lock(irq, &flags, IRQ_GET_DESC_CHECK_PERCPU); if (!desc) return; irq_percpu_disable(desc, cpu); irq_put_desc_unlock(desc, flags); } EXPORT_SYMBOL_GPL(disable_percpu_irq); void disable_percpu_nmi(unsigned int irq) { disable_percpu_irq(irq); } /* * Internal function to unregister a percpu irqaction. */ static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_id) { struct irq_desc *desc = irq_to_desc(irq); struct irqaction *action; unsigned long flags; WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); if (!desc) return NULL; raw_spin_lock_irqsave(&desc->lock, flags); action = desc->action; if (!action || action->percpu_dev_id != dev_id) { WARN(1, "Trying to free already-free IRQ %d\n", irq); goto bad; } if (!cpumask_empty(desc->percpu_enabled)) { WARN(1, "percpu IRQ %d still enabled on CPU%d!\n", irq, cpumask_first(desc->percpu_enabled)); goto bad; } /* Found it - now remove it from the list of entries: */ desc->action = NULL; desc->istate &= ~IRQS_NMI; raw_spin_unlock_irqrestore(&desc->lock, flags); unregister_handler_proc(irq, action); irq_chip_pm_put(&desc->irq_data); module_put(desc->owner); return action; bad: raw_spin_unlock_irqrestore(&desc->lock, flags); return NULL; } /** * remove_percpu_irq - free a per-cpu interrupt * @irq: Interrupt line to free * @act: irqaction for the interrupt * * Used to remove interrupts statically setup by the early boot process. */ void remove_percpu_irq(unsigned int irq, struct irqaction *act) { struct irq_desc *desc = irq_to_desc(irq); if (desc && irq_settings_is_per_cpu_devid(desc)) __free_percpu_irq(irq, act->percpu_dev_id); } /** * free_percpu_irq - free an interrupt allocated with request_percpu_irq * @irq: Interrupt line to free * @dev_id: Device identity to free * * Remove a percpu interrupt handler. The handler is removed, but * the interrupt line is not disabled. This must be done on each * CPU before calling this function. The function does not return * until any executing interrupts for this IRQ have completed. * * This function must not be called from interrupt context. */ void free_percpu_irq(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; chip_bus_lock(desc); kfree(__free_percpu_irq(irq, dev_id)); 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 * @irq: Interrupt line to setup * @act: irqaction for the interrupt * * Used to statically setup per-cpu interrupts in the early boot process. */ int setup_percpu_irq(unsigned int irq, struct irqaction *act) { struct irq_desc *desc = irq_to_desc(irq); int retval; if (!desc || !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; } /** * __request_percpu_irq - allocate a percpu interrupt line * @irq: Interrupt line to allocate * @handler: Function to be called when the IRQ occurs. * @flags: Interrupt type flags (IRQF_TIMER only) * @devname: An ascii name for the claiming device * @dev_id: A percpu cookie passed back to the handler function * * This call allocates interrupt resources and enables the * interrupt on the local CPU. If the interrupt is supposed to be * enabled on other CPUs, it has to be done on each CPU using * enable_percpu_irq(). * * 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. */ int __request_percpu_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, const char *devname, void __percpu *dev_id) { struct irqaction *action; struct irq_desc *desc; int retval; if (!dev_id) return -EINVAL; desc = irq_to_desc(irq); if (!desc || !irq_settings_can_request(desc) || !irq_settings_is_per_cpu_devid(desc)) return -EINVAL; if (flags && flags != IRQF_TIMER) return -EINVAL; action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); if (!action) return -ENOMEM; action->handler = handler; action->flags = flags | IRQF_PERCPU | IRQF_NO_SUSPEND; action->name = devname; action->percpu_dev_id = dev_id; retval = irq_chip_pm_get(&desc->irq_data); if (retval < 0) { kfree(action); return retval; } retval = __setup_irq(irq, desc, action); if (retval) { irq_chip_pm_put(&desc->irq_data); kfree(action); } return retval; } 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) { struct irq_chip *chip; int err = -EINVAL; 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 data = data->parent_data; #else data = NULL; #endif } while (data); if (data) err = chip->irq_get_irqchip_state(data, which, state); return err; } /** * irq_get_irqchip_state - returns the irqchip state of a interrupt. * @irq: Interrupt line that is forwarded to a VM * @which: One of IRQCHIP_STATE_* the caller wants to know about * @state: a pointer to a boolean where the state is to be storeed * * This call snapshots the internal irqchip state of an * interrupt, returning into @state the bit corresponding to * stage @which * * This function should be called with preemption disabled if the * interrupt controller has per-cpu registers. */ int irq_get_irqchip_state(unsigned int irq, enum irqchip_irq_state which, bool *state) { struct irq_desc *desc; struct irq_data *data; unsigned long flags; int err = -EINVAL; desc = irq_get_desc_buslock(irq, &flags, 0); if (!desc) return err; data = irq_desc_get_irq_data(desc); err = __irq_get_irqchip_state(data, which, state); irq_put_desc_busunlock(desc, flags); return err; } EXPORT_SYMBOL_GPL(irq_get_irqchip_state); /** * irq_set_irqchip_state - set the state of a forwarded interrupt. * @irq: Interrupt line that is forwarded to a VM * @which: State to be restored (one of IRQCHIP_STATE_*) * @val: Value corresponding to @which * * This call sets the internal irqchip state of an interrupt, * depending on the value of @which. * * 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, bool val) { struct irq_desc *desc; struct irq_data *data; struct irq_chip *chip; unsigned long flags; int err = -EINVAL; desc = irq_get_desc_buslock(irq, &flags, 0); if (!desc) return err; data = irq_desc_get_irq_data(desc); 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 data = data->parent_data; #else data = NULL; #endif } while (data); if (data) err = chip->irq_set_irqchip_state(data, which, val); out_unlock: irq_put_desc_busunlock(desc, flags); return err; } EXPORT_SYMBOL_GPL(irq_set_irqchip_state);