diff options
Diffstat (limited to 'kernel/irq/manage.c')
| -rw-r--r-- | kernel/irq/manage.c | 1116 |
1 files changed, 825 insertions, 291 deletions
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 0caa59f747dd..514bcfd855a8 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -7,6 +7,8 @@ * 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> @@ -14,9 +16,22 @@ #include <linux/interrupt.h> #include <linux/slab.h> #include <linux/sched.h> +#include <linux/sched/rt.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 + /** * synchronize_irq - wait for pending IRQ handlers (on other CPUs) * @irq: interrupt number to wait for @@ -30,7 +45,7 @@ void synchronize_irq(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); - unsigned int status; + bool inprogress; if (!desc) return; @@ -42,16 +57,16 @@ void synchronize_irq(unsigned int irq) * Wait until we're out of the critical section. This might * give the wrong answer due to the lack of memory barriers. */ - while (desc->status & IRQ_INPROGRESS) + 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); - status = desc->status; + inprogress = irqd_irq_inprogress(&desc->irq_data); raw_spin_unlock_irqrestore(&desc->lock, flags); /* Oops, that failed? */ - } while (status & IRQ_INPROGRESS); + } while (inprogress); /* * We made sure that no hardirq handler is running. Now verify @@ -73,8 +88,8 @@ int irq_can_set_affinity(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); - if (CHECK_IRQ_PER_CPU(desc->status) || !desc->irq_data.chip || - !desc->irq_data.chip->irq_set_affinity) + if (!desc || !irqd_can_balance(&desc->irq_data) || + !desc->irq_data.chip || !desc->irq_data.chip->irq_set_affinity) return 0; return 1; @@ -100,67 +115,191 @@ void irq_set_thread_affinity(struct irq_desc *desc) } } +#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, false); + switch (ret) { + case IRQ_SET_MASK_OK: + cpumask_copy(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) +{ + 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, false); + } 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; +} + /** * irq_set_affinity - Set the irq affinity of a given irq * @irq: Interrupt to set affinity - * @cpumask: cpumask + * @mask: cpumask * */ -int irq_set_affinity(unsigned int irq, const struct cpumask *cpumask) +int irq_set_affinity(unsigned int irq, const struct cpumask *mask) { struct irq_desc *desc = irq_to_desc(irq); - struct irq_chip *chip = desc->irq_data.chip; unsigned long flags; + int ret; - if (!chip->irq_set_affinity) + if (!desc) return -EINVAL; raw_spin_lock_irqsave(&desc->lock, flags); - -#ifdef CONFIG_GENERIC_PENDING_IRQ - if (desc->status & IRQ_MOVE_PCNTXT) { - if (!chip->irq_set_affinity(&desc->irq_data, cpumask, false)) { - cpumask_copy(desc->irq_data.affinity, cpumask); - irq_set_thread_affinity(desc); - } - } - else { - desc->status |= IRQ_MOVE_PENDING; - cpumask_copy(desc->pending_mask, cpumask); - } -#else - if (!chip->irq_set_affinity(&desc->irq_data, cpumask, false)) { - cpumask_copy(desc->irq_data.affinity, cpumask); - irq_set_thread_affinity(desc); - } -#endif - desc->status |= IRQ_AFFINITY_SET; + ret = __irq_set_affinity_locked(irq_desc_get_irq_data(desc), mask); raw_spin_unlock_irqrestore(&desc->lock, flags); - return 0; + 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); + 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_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); - desc->affinity_hint = m; + 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_hint); +EXPORT_SYMBOL_GPL(irq_set_affinity_notifier); #ifndef CONFIG_AUTO_IRQ_AFFINITY /* * Generic version of the affinity autoselector. */ -static int setup_affinity(unsigned int irq, struct irq_desc *desc) +static int +setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask) { + struct cpumask *set = irq_default_affinity; + int node = desc->irq_data.node; + + /* Excludes PER_CPU and NO_BALANCE interrupts */ if (!irq_can_set_affinity(irq)) return 0; @@ -168,22 +307,28 @@ static int setup_affinity(unsigned int irq, struct irq_desc *desc) * Preserve an userspace affinity setup, but make sure that * one of the targets is online. */ - if (desc->status & (IRQ_AFFINITY_SET | IRQ_NO_BALANCING)) { - if (cpumask_any_and(desc->irq_data.affinity, cpu_online_mask) - < nr_cpu_ids) - goto set_affinity; + if (irqd_has_set(&desc->irq_data, IRQD_AFFINITY_SET)) { + if (cpumask_intersects(desc->irq_data.affinity, + cpu_online_mask)) + set = desc->irq_data.affinity; else - desc->status &= ~IRQ_AFFINITY_SET; + irqd_clear(&desc->irq_data, IRQD_AFFINITY_SET); } - cpumask_and(desc->irq_data.affinity, cpu_online_mask, irq_default_affinity); -set_affinity: - desc->irq_data.chip->irq_set_affinity(&desc->irq_data, desc->irq_data.affinity, false); + 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 -static inline int setup_affinity(unsigned int irq, struct irq_desc *d) +static inline int +setup_affinity(unsigned int irq, struct irq_desc *d, struct cpumask *mask) { return irq_select_affinity(irq); } @@ -192,23 +337,21 @@ static inline int setup_affinity(unsigned int irq, struct irq_desc *d) /* * Called when affinity is set via /proc/irq */ -int irq_select_affinity_usr(unsigned int 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(irq, desc); - if (!ret) - irq_set_thread_affinity(desc); + ret = setup_affinity(irq, desc, mask); raw_spin_unlock_irqrestore(&desc->lock, flags); - return ret; } #else -static inline int setup_affinity(unsigned int irq, struct irq_desc *desc) +static inline int +setup_affinity(unsigned int irq, struct irq_desc *desc, struct cpumask *mask) { return 0; } @@ -219,13 +362,23 @@ void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend) if (suspend) { if (!desc->action || (desc->action->flags & IRQF_NO_SUSPEND)) return; - desc->status |= IRQ_SUSPENDED; + desc->istate |= IRQS_SUSPENDED; } - if (!desc->depth++) { - desc->status |= IRQ_DISABLED; - desc->irq_data.chip->irq_disable(&desc->irq_data); - } + 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, false); + irq_put_desc_busunlock(desc, flags); + return 0; } /** @@ -241,17 +394,7 @@ void __disable_irq(struct irq_desc *desc, unsigned int irq, bool suspend) */ void disable_irq_nosync(unsigned int irq) { - struct irq_desc *desc = irq_to_desc(irq); - unsigned long flags; - - if (!desc) - return; - - chip_bus_lock(desc); - raw_spin_lock_irqsave(&desc->lock, flags); - __disable_irq(desc, irq, false); - raw_spin_unlock_irqrestore(&desc->lock, flags); - chip_bus_sync_unlock(desc); + __disable_irq_nosync(irq); } EXPORT_SYMBOL(disable_irq_nosync); @@ -269,21 +412,24 @@ EXPORT_SYMBOL(disable_irq_nosync); */ void disable_irq(unsigned int irq) { - struct irq_desc *desc = irq_to_desc(irq); - - if (!desc) - return; - - disable_irq_nosync(irq); - if (desc->action) + if (!__disable_irq_nosync(irq)) synchronize_irq(irq); } EXPORT_SYMBOL(disable_irq); void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume) { - if (resume) - desc->status &= ~IRQ_SUSPENDED; + if (resume) { + if (!(desc->istate & IRQS_SUSPENDED)) { + if (!desc->action) + return; + if (!(desc->action->flags & IRQF_FORCE_RESUME)) + return; + /* Pretend that it got disabled ! */ + desc->depth++; + } + desc->istate &= ~IRQS_SUSPENDED; + } switch (desc->depth) { case 0: @@ -291,12 +437,11 @@ void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume) WARN(1, KERN_WARNING "Unbalanced enable for IRQ %d\n", irq); break; case 1: { - unsigned int status = desc->status & ~IRQ_DISABLED; - - if (desc->status & IRQ_SUSPENDED) + if (desc->istate & IRQS_SUSPENDED) goto err_out; /* Prevent probing on this irq: */ - desc->status = status | IRQ_NOPROBE; + irq_settings_set_noprobe(desc); + irq_enable(desc); check_irq_resend(desc, irq); /* fall-through */ } @@ -318,21 +463,18 @@ void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume) */ void enable_irq(unsigned int irq) { - struct irq_desc *desc = irq_to_desc(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; - if (WARN(!desc->irq_data.chip || !desc->irq_data.chip->irq_enable, - KERN_ERR "enable_irq before setup/request_irq: irq %u\n", irq)) - return; - - chip_bus_lock(desc); - raw_spin_lock_irqsave(&desc->lock, flags); __enable_irq(desc, irq, false); - raw_spin_unlock_irqrestore(&desc->lock, flags); - chip_bus_sync_unlock(desc); +out: + irq_put_desc_busunlock(desc, flags); } EXPORT_SYMBOL(enable_irq); @@ -341,6 +483,9 @@ 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); @@ -348,7 +493,7 @@ static int set_irq_wake_real(unsigned int irq, unsigned int on) } /** - * set_irq_wake - control irq power management wakeup + * irq_set_irq_wake - control irq power management wakeup * @irq: interrupt to control * @on: enable/disable power management wakeup * @@ -359,23 +504,25 @@ static int set_irq_wake_real(unsigned int irq, unsigned int on) * Wakeup mode lets this IRQ wake the system from sleep * states like "suspend to RAM". */ -int set_irq_wake(unsigned int irq, unsigned int on) +int irq_set_irq_wake(unsigned int irq, unsigned int on) { - struct irq_desc *desc = irq_to_desc(irq); 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. */ - raw_spin_lock_irqsave(&desc->lock, flags); if (on) { if (desc->wake_depth++ == 0) { ret = set_irq_wake_real(irq, on); if (ret) desc->wake_depth = 0; else - desc->status |= IRQ_WAKEUP; + irqd_set(&desc->irq_data, IRQD_WAKEUP_STATE); } } else { if (desc->wake_depth == 0) { @@ -385,14 +532,13 @@ int set_irq_wake(unsigned int irq, unsigned int on) if (ret) desc->wake_depth = 1; else - desc->status &= ~IRQ_WAKEUP; + irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE); } } - - raw_spin_unlock_irqrestore(&desc->lock, flags); + irq_put_desc_busunlock(desc, flags); return ret; } -EXPORT_SYMBOL(set_irq_wake); +EXPORT_SYMBOL(irq_set_irq_wake); /* * Internal function that tells the architecture code whether a @@ -401,43 +547,27 @@ EXPORT_SYMBOL(set_irq_wake); */ int can_request_irq(unsigned int irq, unsigned long irqflags) { - struct irq_desc *desc = irq_to_desc(irq); - struct irqaction *action; unsigned long flags; + struct irq_desc *desc = irq_get_desc_lock(irq, &flags, 0); + int canrequest = 0; if (!desc) return 0; - if (desc->status & IRQ_NOREQUEST) - return 0; - - raw_spin_lock_irqsave(&desc->lock, flags); - action = desc->action; - if (action) - if (irqflags & action->flags & IRQF_SHARED) - action = NULL; - - raw_spin_unlock_irqrestore(&desc->lock, flags); - - return !action; -} - -void compat_irq_chip_set_default_handler(struct irq_desc *desc) -{ - /* - * If the architecture still has not overriden - * the flow handler then zap the default. This - * should catch incorrect flow-type setting. - */ - if (desc->handle_irq == &handle_bad_irq) - desc->handle_irq = NULL; + 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 int irq, unsigned long flags) { - int ret; struct irq_chip *chip = desc->irq_data.chip; + int ret, unmask = 0; if (!chip || !chip->irq_set_type) { /* @@ -445,30 +575,64 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, * flow-types? */ pr_debug("No set_type function for IRQ %d (%s)\n", irq, - chip ? (chip->name ? : "unknown") : "unknown"); + chip ? (chip->name ? : "unknown") : "unknown"); return 0; } + flags &= IRQ_TYPE_SENSE_MASK; + + 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; + } + /* caller masked out all except trigger mode flags */ ret = chip->irq_set_type(&desc->irq_data, flags); - if (ret) - pr_err("setting trigger mode %lu for irq %u failed (%pF)\n", + switch (ret) { + case IRQ_SET_MASK_OK: + 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, chip->irq_set_type); - else { - if (flags & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH)) - flags |= IRQ_LEVEL; - /* note that IRQF_TRIGGER_MASK == IRQ_TYPE_SENSE_MASK */ - desc->status &= ~(IRQ_LEVEL | IRQ_TYPE_SENSE_MASK); - desc->status |= flags; - - if (chip != desc->irq_data.chip) - irq_chip_set_defaults(desc->irq_data.chip); } - + 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; +} +#endif + /* * Default primary interrupt handler for threaded interrupts. Is * assigned as primary handler when request_threaded_irq is called @@ -491,8 +655,9 @@ static irqreturn_t irq_nested_primary_handler(int irq, void *dev_id) static int irq_wait_for_interrupt(struct irqaction *action) { + set_current_state(TASK_INTERRUPTIBLE); + while (!kthread_should_stop()) { - set_current_state(TASK_INTERRUPTIBLE); if (test_and_clear_bit(IRQTF_RUNTHREAD, &action->thread_flags)) { @@ -500,7 +665,9 @@ static int irq_wait_for_interrupt(struct irqaction *action) return 0; } schedule(); + set_current_state(TASK_INTERRUPTIBLE); } + __set_current_state(TASK_RUNNING); return -1; } @@ -509,8 +676,11 @@ static int irq_wait_for_interrupt(struct irqaction *action) * handler finished. unmask if the interrupt has not been disabled and * is marked MASKED. */ -static void irq_finalize_oneshot(unsigned int irq, struct irq_desc *desc) +static void irq_finalize_oneshot(struct irq_desc *desc, + struct irqaction *action) { + if (!(desc->istate & IRQS_ONESHOT)) + return; again: chip_bus_lock(desc); raw_spin_lock_irq(&desc->lock); @@ -522,31 +692,48 @@ again: * 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 IRQ_INPROGRESS and the irq line is masked forever. + * 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(desc->status & IRQ_INPROGRESS)) { + if (unlikely(irqd_irq_inprogress(&desc->irq_data))) { raw_spin_unlock_irq(&desc->lock); chip_bus_sync_unlock(desc); cpu_relax(); goto again; } - if (!(desc->status & IRQ_DISABLED) && (desc->status & IRQ_MASKED)) { - desc->status &= ~IRQ_MASKED; - desc->irq_data.chip->irq_unmask(&desc->irq_data); - } + /* + * 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_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. + * Check whether we need to chasnge 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; @@ -561,10 +748,18 @@ irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) } raw_spin_lock_irq(&desc->lock); - cpumask_copy(mask, desc->irq_data.affinity); + /* + * This code is triggered unconditionally. Check the affinity + * mask pointer. For CPU_MASK_OFFSTACK=n this is optimized out. + */ + if (desc->irq_data.affinity) + cpumask_copy(mask, desc->irq_data.affinity); + else + valid = false; raw_spin_unlock_irq(&desc->lock); - set_cpus_allowed_ptr(current, mask); + if (valid) + set_cpus_allowed_ptr(current, mask); free_cpumask_var(mask); } #else @@ -573,79 +768,133 @@ irq_thread_check_affinity(struct irq_desc *desc, struct irqaction *action) { } #endif /* - * Interrupt handler thread + * 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 int irq_thread(void *data) +static irqreturn_t +irq_forced_thread_fn(struct irq_desc *desc, struct irqaction *action) { - static const struct sched_param param = { - .sched_priority = MAX_USER_RT_PRIO/2, - }; - struct irqaction *action = data; - struct irq_desc *desc = irq_to_desc(action->irq); - int wake, oneshot = desc->status & IRQ_ONESHOT; + irqreturn_t ret; - sched_setscheduler(current, SCHED_FIFO, ¶m); - current->irqaction = action; + local_bh_disable(); + ret = action->thread_fn(action->irq, action->dev_id); + irq_finalize_oneshot(desc, action); + local_bh_enable(); + return ret; +} - while (!irq_wait_for_interrupt(action)) { +/* + * Interrupts explicitely requested as threaded interupts 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; - irq_thread_check_affinity(desc, action); + ret = action->thread_fn(action->irq, action->dev_id); + irq_finalize_oneshot(desc, action); + return ret; +} - atomic_inc(&desc->threads_active); +static void wake_threads_waitq(struct irq_desc *desc) +{ + if (atomic_dec_and_test(&desc->threads_active) && + waitqueue_active(&desc->wait_for_threads)) + wake_up(&desc->wait_for_threads); +} - raw_spin_lock_irq(&desc->lock); - if (unlikely(desc->status & IRQ_DISABLED)) { - /* - * CHECKME: We might need a dedicated - * IRQ_THREAD_PENDING flag here, which - * retriggers the thread in check_irq_resend() - * but AFAICT IRQ_PENDING should be fine as it - * retriggers the interrupt itself --- tglx - */ - desc->status |= IRQ_PENDING; - raw_spin_unlock_irq(&desc->lock); - } else { - raw_spin_unlock_irq(&desc->lock); +static void irq_thread_dtor(struct callback_head *unused) +{ + struct task_struct *tsk = current; + struct irq_desc *desc; + struct irqaction *action; - action->thread_fn(action->irq, action->dev_id); + if (WARN_ON_ONCE(!(current->flags & PF_EXITING))) + return; - if (oneshot) - irq_finalize_oneshot(action->irq, desc); - } + action = kthread_data(tsk); - wake = atomic_dec_and_test(&desc->threads_active); + pr_err("exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n", + tsk->comm, tsk->pid, action->irq); - if (wake && waitqueue_active(&desc->wait_for_threads)) - wake_up(&desc->wait_for_threads); - } + desc = irq_to_desc(action->irq); /* - * Clear irqaction. Otherwise exit_irq_thread() would make - * fuzz about an active irq thread going into nirvana. + * If IRQTF_RUNTHREAD is set, we need to decrement + * desc->threads_active and wake possible waiters. */ - current->irqaction = NULL; - return 0; + 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); } /* - * Called from do_exit() + * Interrupt handler thread */ -void exit_irq_thread(void) +static int irq_thread(void *data) { - struct task_struct *tsk = current; + 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 (!tsk->irqaction) - return; + 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); - printk(KERN_ERR - "exiting task \"%s\" (%d) is an active IRQ thread (irq %d)\n", - tsk->comm ? tsk->comm : "", tsk->pid, tsk->irqaction->irq); + 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 (!noirqdebug) + note_interrupt(action->irq, desc, action_ret); + + wake_threads_waitq(desc); + } /* - * Set the THREAD DIED flag to prevent further wakeups of the - * soon to be gone threaded handler. + * 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. */ - set_bit(IRQTF_DIED, &tsk->irqaction->flags); + task_work_cancel(current, irq_thread_dtor); + return 0; +} + +static void irq_setup_forced_threading(struct irqaction *new) +{ + if (!force_irqthreads) + return; + if (new->flags & (IRQF_NO_THREAD | IRQF_PERCPU | IRQF_ONESHOT)) + return; + + new->flags |= IRQF_ONESHOT; + + if (!new->thread_fn) { + set_bit(IRQTF_FORCED_THREAD, &new->thread_flags); + new->thread_fn = new->handler; + new->handler = irq_default_primary_handler; + } } /* @@ -656,51 +905,37 @@ static int __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) { struct irqaction *old, **old_ptr; - const char *old_name = NULL; - unsigned long flags; - int nested, shared = 0; - int ret; + 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; - /* - * Some drivers like serial.c use request_irq() heavily, - * so we have to be careful not to interfere with a - * running system. - */ - if (new->flags & IRQF_SAMPLE_RANDOM) { - /* - * This function might sleep, we want to call it first, - * outside of the atomic block. - * Yes, this might clear the entropy pool if the wrong - * driver is attempted to be loaded, without actually - * installing a new handler, but is this really a problem, - * only the sysadmin is able to do this. - */ - rand_initialize_irq(irq); - } - - /* Oneshot interrupts are not allowed with shared */ - if ((new->flags & IRQF_ONESHOT) && (new->flags & IRQF_SHARED)) - return -EINVAL; + if (!try_module_get(desc->owner)) + return -ENODEV; /* * Check whether the interrupt nests into another interrupt * thread. */ - nested = desc->status & IRQ_NESTED_THREAD; + nested = irq_settings_is_nested_thread(desc); if (nested) { - if (!new->thread_fn) - return -EINVAL; + 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)) + irq_setup_forced_threading(new); } /* @@ -710,11 +945,19 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) */ if (new->thread_fn && !nested) { struct task_struct *t; + static const struct sched_param param = { + .sched_priority = MAX_USER_RT_PRIO/2, + }; t = kthread_create(irq_thread, new, "irq/%d-%s", irq, new->name); - if (IS_ERR(t)) - return PTR_ERR(t); + if (IS_ERR(t)) { + ret = PTR_ERR(t); + goto out_mput; + } + + sched_setscheduler(t, SCHED_FIFO, ¶m); + /* * We keep the reference to the task struct even if * the thread dies to avoid that the interrupt code @@ -722,9 +965,36 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) */ 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); + } + + 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); @@ -735,32 +1005,93 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) * 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. + * set the trigger type must match. Also all must + * agree on ONESHOT. */ if (!((old->flags & new->flags) & IRQF_SHARED) || - ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK)) { - old_name = old->name; + ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) || + ((old->flags ^ new->flags) & IRQF_ONESHOT)) goto mismatch; - } -#if defined(CONFIG_IRQ_PER_CPU) /* All handlers must agree on per-cpuness */ if ((old->flags & IRQF_PERCPU) != (new->flags & IRQF_PERCPU)) goto mismatch; -#endif /* 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; } - if (!shared) { - irq_chip_set_defaults(desc->irq_data.chip); + /* + * 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) { init_waitqueue_head(&desc->wait_for_threads); /* Setup the type (level, edge polarity) if configured: */ @@ -769,42 +1100,44 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) new->flags & IRQF_TRIGGER_MASK); if (ret) - goto out_thread; - } else - compat_irq_chip_set_default_handler(desc); -#if defined(CONFIG_IRQ_PER_CPU) - if (new->flags & IRQF_PERCPU) - desc->status |= IRQ_PER_CPU; -#endif + goto out_mask; + } - desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | IRQ_ONESHOT | - IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED); + 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->status |= IRQ_ONESHOT; + desc->istate |= IRQS_ONESHOT; - if (!(desc->status & IRQ_NOAUTOEN)) { - desc->depth = 0; - desc->status &= ~IRQ_DISABLED; - desc->irq_data.chip->irq_startup(&desc->irq_data); - } else + 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) - desc->status |= IRQ_NO_BALANCING; + 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(irq, desc); - - } else if ((new->flags & IRQF_TRIGGER_MASK) - && (new->flags & IRQF_TRIGGER_MASK) - != (desc->status & IRQ_TYPE_SENSE_MASK)) { - /* hope the handler works with the actual trigger mode... */ - pr_warning("IRQ %d uses trigger mode %d; requested %d\n", - irq, (int)(desc->status & IRQ_TYPE_SENSE_MASK), - (int)(new->flags & IRQF_TRIGGER_MASK)); + setup_affinity(irq, desc, mask); + + } else if (new->flags & IRQF_TRIGGER_MASK) { + unsigned int nmsk = new->flags & IRQF_TRIGGER_MASK; + unsigned int omsk = irq_settings_get_trigger_mask(desc); + + if (nmsk != omsk) + /* hope the handler works with current trigger mode */ + pr_warning("irq %d uses trigger mode %u; requested %u\n", + irq, nmsk, omsk); } new->irq = irq; @@ -818,8 +1151,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) * Check whether we disabled the irq via the spurious handler * before. Reenable it and give it another chance. */ - if (shared && (desc->status & IRQ_SPURIOUS_DISABLED)) { - desc->status &= ~IRQ_SPURIOUS_DISABLED; + if (shared && (desc->istate & IRQS_SPURIOUS_DISABLED)) { + desc->istate &= ~IRQS_SPURIOUS_DISABLED; __enable_irq(desc, irq, false); } @@ -835,30 +1168,34 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) register_irq_proc(irq, desc); new->dir = NULL; register_handler_proc(irq, new); + free_cpumask_var(mask); return 0; mismatch: -#ifdef CONFIG_DEBUG_SHIRQ if (!(new->flags & IRQF_PROBE_SHARED)) { - printk(KERN_ERR "IRQ handler type mismatch for IRQ %d\n", irq); - if (old_name) - printk(KERN_ERR "current handler: %s\n", old_name); + 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_thread: +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; - if (likely(!test_bit(IRQTF_DIED, &new->thread_flags))) - kthread_stop(t); + kthread_stop(t); put_task_struct(t); } +out_mput: + module_put(desc->owner); return ret; } @@ -871,13 +1208,20 @@ out_thread: */ int setup_irq(unsigned int irq, struct irqaction *act) { + int retval; struct irq_desc *desc = irq_to_desc(irq); - return __setup_irq(irq, desc, act); + if (WARN_ON(irq_settings_is_per_cpu_devid(desc))) + return -EINVAL; + chip_bus_lock(desc); + retval = __setup_irq(irq, desc, act); + chip_bus_sync_unlock(desc); + + 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. */ @@ -917,20 +1261,9 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) /* Found it - now remove it from the list of entries: */ *action_ptr = action->next; - /* Currently used only by UML, might disappear one day: */ -#ifdef CONFIG_IRQ_RELEASE_METHOD - if (desc->irq_data.chip->release) - desc->irq_data.chip->release(irq, dev_id); -#endif - /* If this was the last handler, shut down the IRQ line: */ - if (!desc->action) { - desc->status |= IRQ_DISABLED; - if (desc->irq_data.chip->irq_shutdown) - desc->irq_data.chip->irq_shutdown(&desc->irq_data); - else - desc->irq_data.chip->irq_disable(&desc->irq_data); - } + if (!desc->action) + irq_shutdown(desc); #ifdef CONFIG_SMP /* make sure affinity_hint is cleaned up */ @@ -962,11 +1295,11 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) #endif if (action->thread) { - if (!test_bit(IRQTF_DIED, &action->thread_flags)) - kthread_stop(action->thread); + kthread_stop(action->thread); put_task_struct(action->thread); } + module_put(desc->owner); return action; } @@ -979,7 +1312,10 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) */ void remove_irq(unsigned int irq, struct irqaction *act) { - __free_irq(irq, act->dev_id); + 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); @@ -1001,9 +1337,14 @@ void free_irq(unsigned int irq, void *dev_id) { struct irq_desc *desc = irq_to_desc(irq); - if (!desc) + if (!desc || WARN_ON(irq_settings_is_per_cpu_devid(desc))) return; +#ifdef CONFIG_SMP + if (WARN_ON(desc->affinity_notify)) + desc->affinity_notify = NULL; +#endif + chip_bus_lock(desc); kfree(__free_irq(irq, dev_id)); chip_bus_sync_unlock(desc); @@ -1031,7 +1372,7 @@ EXPORT_SYMBOL(free_irq); * 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 ist + * 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 @@ -1049,7 +1390,6 @@ EXPORT_SYMBOL(free_irq); * Flags: * * IRQF_SHARED Interrupt is shared - * IRQF_SAMPLE_RANDOM The interrupt can be used for entropy * IRQF_TRIGGER_* Specify active edge(s) or level * */ @@ -1074,7 +1414,8 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler, if (!desc) return -EINVAL; - if (desc->status & IRQ_NOREQUEST) + if (!irq_settings_can_request(desc) || + WARN_ON(irq_settings_is_per_cpu_devid(desc))) return -EINVAL; if (!handler) { @@ -1100,7 +1441,7 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler, if (retval) kfree(action); -#ifdef CONFIG_DEBUG_SHIRQ +#ifdef CONFIG_DEBUG_SHIRQ_FIXME if (!retval && (irqflags & IRQF_SHARED)) { /* * It's a shared IRQ -- the driver ought to be prepared for it @@ -1149,7 +1490,7 @@ int request_any_context_irq(unsigned int irq, irq_handler_t handler, if (!desc) return -EINVAL; - if (desc->status & IRQ_NESTED_THREAD) { + if (irq_settings_is_nested_thread(desc)) { ret = request_threaded_irq(irq, NULL, handler, flags, name, dev_id); return !ret ? IRQC_IS_NESTED : ret; @@ -1159,3 +1500,196 @@ int request_any_context_irq(unsigned int irq, irq_handler_t handler, 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; + + type &= IRQ_TYPE_SENSE_MASK; + if (type != IRQ_TYPE_NONE) { + int ret; + + ret = __irq_set_trigger(desc, irq, 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 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); + + 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); +} + +/** + * 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; + chip_bus_lock(desc); + retval = __setup_irq(irq, desc, act); + chip_bus_sync_unlock(desc); + + 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, but doesn't + * automatically enable the interrupt. 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; + + chip_bus_lock(desc); + retval = __setup_irq(irq, desc, action); + chip_bus_sync_unlock(desc); + + if (retval) + kfree(action); + + return retval; +} |