| /* |
| * linux/kernel/irq/manage.c |
| * |
| * 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 <linux/irq.h> |
| #include <linux/kthread.h> |
| #include <linux/module.h> |
| #include <linux/random.h> |
| #include <linux/interrupt.h> |
| #include <linux/slab.h> |
| #include <linux/sched.h> |
| #include <linux/sched/rt.h> |
| #include <linux/sched/task.h> |
| #include <uapi/linux/sched/types.h> |
| #include <linux/task_work.h> |
| |
| #include "internals.h" |
| |
| #ifdef CONFIG_IRQ_FORCED_THREADING |
| __read_mostly bool 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 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); |
| 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. |
| */ |
| bool synchronize_hardirq(unsigned int irq) |
| { |
| struct irq_desc *desc = irq_to_desc(irq); |
| |
| if (desc) { |
| __synchronize_hardirq(desc); |
| 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. |
| * |
| * This function may be called - with care - from IRQ context. |
| */ |
| void synchronize_irq(unsigned int irq) |
| { |
| struct irq_desc *desc = irq_to_desc(irq); |
| |
| if (desc) { |
| __synchronize_hardirq(desc); |
| /* |
| * 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_PENDING_IRQ |
| static inline bool irq_can_move_pcntxt(struct irq_data *data) |
| { |
| return irqd_can_move_in_process_context(data); |
| } |
| static inline bool irq_move_pending(struct irq_data *data) |
| { |
| return irqd_is_setaffinity_pending(data); |
| } |
| static inline void |
| irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) |
| { |
| cpumask_copy(desc->pending_mask, mask); |
| } |
| static inline void |
| irq_get_pending(struct cpumask *mask, struct irq_desc *desc) |
| { |
| cpumask_copy(mask, desc->pending_mask); |
| } |
| #else |
| static inline bool irq_can_move_pcntxt(struct irq_data *data) { return true; } |
| static inline bool irq_move_pending(struct irq_data *data) { return false; } |
| static inline void |
| irq_copy_pending(struct irq_desc *desc, const struct cpumask *mask) { } |
| static inline void |
| irq_get_pending(struct cpumask *mask, struct irq_desc *desc) { } |
| #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; |
| |
| 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); |
| case IRQ_SET_MASK_OK_NOCOPY: |
| irq_set_thread_affinity(desc); |
| ret = 0; |
| } |
| |
| return ret; |
| } |
| |
| 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_can_move_pcntxt(data)) { |
| ret = irq_do_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); |
| schedule_work(&desc->affinity_notify->work); |
| } |
| 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) |
| 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) |
| 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. |
| */ |
| static int setup_affinity(struct irq_desc *desc, struct cpumask *mask) |
| { |
| struct cpumask *set = irq_default_affinity; |
| int node = irq_desc_get_node(desc); |
| |
| /* Excludes PER_CPU and NO_BALANCE interrupts */ |
| if (!__irq_can_set_affinity(desc)) |
| return 0; |
| |
| /* |
| * 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 (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); |
| } |
| irq_do_set_affinity(&desc->irq_data, mask, false); |
| return 0; |
| } |
| #else |
| /* Wrapper for ALPHA specific affinity selector magic */ |
| static inline int setup_affinity(struct irq_desc *d, struct cpumask *mask) |
| { |
| return irq_select_affinity(irq_desc_get_irq(d)); |
| } |
| #endif |
| |
| /* |
| * Called when affinity is set via /proc/irq |
| */ |
| int irq_select_affinity_usr(unsigned int irq, struct cpumask *mask) |
| { |
| struct irq_desc *desc = irq_to_desc(irq); |
| unsigned long flags; |
| int ret; |
| |
| raw_spin_lock_irqsave(&desc->lock, flags); |
| ret = setup_affinity(desc, mask); |
| raw_spin_unlock_irqrestore(&desc->lock, flags); |
| return ret; |
| } |
| |
| #else |
| static inline int |
| setup_affinity(struct irq_desc *desc, struct cpumask *mask) |
| { |
| return 0; |
| } |
| #endif |
| |
| /** |
| * irq_set_vcpu_affinity - Set vcpu affinity for the interrupt |
| * @irq: interrupt number to set affinity |
| * @vcpu_info: vCPU specific data |
| * |
| * 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); |
| chip = irq_data_get_irq_chip(data); |
| if (chip && chip->irq_set_vcpu_affinity) |
| 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); |
| |
| 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); |
| irq_enable(desc); |
| check_irq_resend(desc); |
| /* fall-through */ |
| } |
| 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); |
| |
| 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". |
| */ |
| 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; |
| |
| /* 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); |
| } |
| } |
| 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); |
| |
| 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 (%pF)\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) |
| { |
| set_current_state(TASK_INTERRUPTIBLE); |
| |
| while (!kthread_should_stop()) { |
| |
| if (test_and_clear_bit(IRQTF_RUNTHREAD, |
| &action->thread_flags)) { |
| __set_current_state(TASK_RUNNING); |
| return 0; |
| } |
| schedule(); |
| set_current_state(TASK_INTERRUPTIBLE); |
| } |
| __set_current_state(TASK_RUNNING); |
| return -1; |
| } |
| |
| /* |
| * 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)) |
| cpumask_copy(mask, desc->irq_common_data.affinity); |
| 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 explicitely 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(); |
| ret = action->thread_fn(action->irq, action->dev_id); |
| irq_finalize_oneshot(desc, action); |
| 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); |
| 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, false); |
| |
| 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_HANDLED) |
| atomic_inc(&desc->threads_handled); |
| 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_irq(). So neither IRQTF_RUNTHREAD nor the |
| * oneshot mask bit can be set. We cannot verify that as we |
| * cannot touch the oneshot mask at this point anymore as |
| * __setup_irq() might have given out currents thread_mask |
| * again. |
| */ |
| 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; |
| |
| 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 != irq_default_primary_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 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, |
| new->name); |
| } 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); |
| |
| /* |
| * 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; |
| /* |
| * 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. |
| */ |
| 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; |
| cpumask_var_t mask; |
| |
| 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; |
| } |
| } |
| |
| if (!alloc_cpumask_var(&mask, GFP_KERNEL)) { |
| ret = -ENOMEM; |
| 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; |
| |
| /* |
| * The following block of code has to be executed atomically |
| */ |
| 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. |
| */ |
| unsigned int oldtype = irqd_get_trigger_type(&desc->irq_data); |
| |
| 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_mask; |
| } |
| /* |
| * 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 = 1 << 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 irq %d\n", |
| irq); |
| ret = -EINVAL; |
| goto out_mask; |
| } |
| |
| if (!shared) { |
| 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_mask; |
| } |
| |
| 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) { |
| irq_release_resources(desc); |
| goto out_mask; |
| } |
| } |
| |
| 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; |
| |
| if (irq_settings_can_autoenable(desc)) |
| irq_startup(desc, true); |
| else |
| /* Undo nested disables: */ |
| desc->depth = 1; |
| |
| /* 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); |
| } |
| |
| /* Set default affinity mask once everything is setup */ |
| setup_affinity(desc, mask); |
| |
| } 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); |
| |
| /* |
| * 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); |
| free_cpumask_var(mask); |
| |
| 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_mask: |
| raw_spin_unlock_irqrestore(&desc->lock, flags); |
| free_cpumask_var(mask); |
| |
| 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; |
| } |
| |
| /** |
| * 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; |
| |
| chip_bus_lock(desc); |
| retval = __setup_irq(irq, desc, act); |
| chip_bus_sync_unlock(desc); |
| |
| 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 |
| * regular and special interrupts that are part of the architecture. |
| */ |
| static struct irqaction *__free_irq(unsigned int irq, void *dev_id) |
| { |
| struct irq_desc *desc = irq_to_desc(irq); |
| struct irqaction *action, **action_ptr; |
| unsigned long flags; |
| |
| WARN(in_interrupt(), "Trying to free IRQ %d from IRQ context!\n", irq); |
| |
| if (!desc) |
| return NULL; |
| |
| 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); |
| 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); |
| irq_shutdown(desc); |
| irq_release_resources(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); |
| chip_bus_sync_unlock(desc); |
| |
| unregister_handler_proc(irq, action); |
| |
| /* Make sure it's not being used on another CPU: */ |
| synchronize_irq(irq); |
| |
| #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 |
| |
| 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); |
| } |
| } |
| |
| irq_chip_pm_put(&desc->irq_data); |
| module_put(desc->owner); |
| 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(irq, act->dev_id); |
| } |
| EXPORT_SYMBOL_GPL(remove_irq); |
| |
| /** |
| * 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(irq, dev_id); |
| devname = action->name; |
| kfree(action); |
| return devname; |
| } |
| EXPORT_SYMBOL(free_irq); |
| |
| /** |
| * 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; |
| } |
| |
| chip_bus_lock(desc); |
| retval = __setup_irq(irq, desc, action); |
| chip_bus_sync_unlock(desc); |
| |
| 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); |
| |
| 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); |
| |
| /** |
| * 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); |
| |
| /* |
| * 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; |
| |
| 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); |
| |
| /** |
| * 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; |
| |
| chip_bus_lock(desc); |
| retval = __setup_irq(irq, desc, act); |
| chip_bus_sync_unlock(desc); |
| |
| 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. |
| * @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, |
| 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; |
| |
| action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); |
| if (!action) |
| return -ENOMEM; |
| |
| action->handler = handler; |
| action->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; |
| } |
| |
| chip_bus_lock(desc); |
| retval = __setup_irq(irq, desc, action); |
| chip_bus_sync_unlock(desc); |
| |
| if (retval) { |
| irq_chip_pm_put(&desc->irq_data); |
| kfree(action); |
| } |
| |
| return retval; |
| } |
| EXPORT_SYMBOL_GPL(request_percpu_irq); |
| |
| /** |
| * 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; |
| 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 (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); |
| |
| 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 (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); |
| |
| irq_put_desc_busunlock(desc, flags); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(irq_set_irqchip_state); |