diff options
Diffstat (limited to 'kernel/irq')
| -rw-r--r-- | kernel/irq/chip.c | 74 | ||||
| -rw-r--r-- | kernel/irq/internals.h | 13 | ||||
| -rw-r--r-- | kernel/irq/manage.c | 102 |
3 files changed, 180 insertions, 9 deletions
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 13c68e7..c166019 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -222,6 +222,34 @@ int set_irq_chip_data(unsigned int irq, void *data) } EXPORT_SYMBOL(set_irq_chip_data); +/** + * set_irq_nested_thread - Set/Reset the IRQ_NESTED_THREAD flag of an irq + * + * @irq: Interrupt number + * @nest: 0 to clear / 1 to set the IRQ_NESTED_THREAD flag + * + * The IRQ_NESTED_THREAD flag indicates that on + * request_threaded_irq() no separate interrupt thread should be + * created for the irq as the handler are called nested in the + * context of a demultiplexing interrupt handler thread. + */ +void set_irq_nested_thread(unsigned int irq, int nest) +{ + struct irq_desc *desc = irq_to_desc(irq); + unsigned long flags; + + if (!desc) + return; + + spin_lock_irqsave(&desc->lock, flags); + if (nest) + desc->status |= IRQ_NESTED_THREAD; + else + desc->status &= ~IRQ_NESTED_THREAD; + spin_unlock_irqrestore(&desc->lock, flags); +} +EXPORT_SYMBOL_GPL(set_irq_nested_thread); + /* * default enable function */ @@ -299,6 +327,45 @@ static inline void mask_ack_irq(struct irq_desc *desc, int irq) } } +/* + * handle_nested_irq - Handle a nested irq from a irq thread + * @irq: the interrupt number + * + * Handle interrupts which are nested into a threaded interrupt + * handler. The handler function is called inside the calling + * threads context. + */ +void handle_nested_irq(unsigned int irq) +{ + struct irq_desc *desc = irq_to_desc(irq); + struct irqaction *action; + irqreturn_t action_ret; + + might_sleep(); + + spin_lock_irq(&desc->lock); + + kstat_incr_irqs_this_cpu(irq, desc); + + action = desc->action; + if (unlikely(!action || (desc->status & IRQ_DISABLED))) + goto out_unlock; + + desc->status |= IRQ_INPROGRESS; + spin_unlock_irq(&desc->lock); + + action_ret = action->thread_fn(action->irq, action->dev_id); + if (!noirqdebug) + note_interrupt(irq, desc, action_ret); + + spin_lock_irq(&desc->lock); + desc->status &= ~IRQ_INPROGRESS; + +out_unlock: + spin_unlock_irq(&desc->lock); +} +EXPORT_SYMBOL_GPL(handle_nested_irq); + /** * handle_simple_irq - Simple and software-decoded IRQs. * @irq: the interrupt number @@ -382,7 +449,10 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc) spin_lock(&desc->lock); desc->status &= ~IRQ_INPROGRESS; - if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask) + + if (unlikely(desc->status & IRQ_ONESHOT)) + desc->status |= IRQ_MASKED; + else if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask) desc->chip->unmask(irq); out_unlock: spin_unlock(&desc->lock); @@ -572,6 +642,7 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained, desc->chip = &dummy_irq_chip; } + chip_bus_lock(irq, desc); spin_lock_irqsave(&desc->lock, flags); /* Uninstall? */ @@ -591,6 +662,7 @@ __set_irq_handler(unsigned int irq, irq_flow_handler_t handle, int is_chained, desc->chip->startup(irq); } spin_unlock_irqrestore(&desc->lock, flags); + chip_bus_sync_unlock(irq, desc); } EXPORT_SYMBOL_GPL(__set_irq_handler); diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index e70ed55..1b5d742 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -44,6 +44,19 @@ extern int irq_select_affinity_usr(unsigned int irq); extern void irq_set_thread_affinity(struct irq_desc *desc); +/* Inline functions for support of irq chips on slow busses */ +static inline void chip_bus_lock(unsigned int irq, struct irq_desc *desc) +{ + if (unlikely(desc->chip->bus_lock)) + desc->chip->bus_lock(irq); +} + +static inline void chip_bus_sync_unlock(unsigned int irq, struct irq_desc *desc) +{ + if (unlikely(desc->chip->bus_sync_unlock)) + desc->chip->bus_sync_unlock(irq); +} + /* * Debugging printout: */ diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 0ec9ed8..bde4c66 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -230,9 +230,11 @@ void disable_irq_nosync(unsigned int irq) if (!desc) return; + chip_bus_lock(irq, desc); spin_lock_irqsave(&desc->lock, flags); __disable_irq(desc, irq, false); spin_unlock_irqrestore(&desc->lock, flags); + chip_bus_sync_unlock(irq, desc); } EXPORT_SYMBOL(disable_irq_nosync); @@ -294,7 +296,8 @@ void __enable_irq(struct irq_desc *desc, unsigned int irq, bool resume) * matches the last disable, processing of interrupts on this * IRQ line is re-enabled. * - * This function may be called from IRQ context. + * This function may be called from IRQ context only when + * desc->chip->bus_lock and desc->chip->bus_sync_unlock are NULL ! */ void enable_irq(unsigned int irq) { @@ -304,9 +307,11 @@ void enable_irq(unsigned int irq) if (!desc) return; + chip_bus_lock(irq, desc); spin_lock_irqsave(&desc->lock, flags); __enable_irq(desc, irq, false); spin_unlock_irqrestore(&desc->lock, flags); + chip_bus_sync_unlock(irq, desc); } EXPORT_SYMBOL(enable_irq); @@ -436,6 +441,26 @@ int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, return ret; } +/* + * 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 int irq_wait_for_interrupt(struct irqaction *action) { while (!kthread_should_stop()) { @@ -451,6 +476,23 @@ static int irq_wait_for_interrupt(struct irqaction *action) 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(unsigned int irq, struct irq_desc *desc) +{ + chip_bus_lock(irq, desc); + spin_lock_irq(&desc->lock); + if (!(desc->status & IRQ_DISABLED) && (desc->status & IRQ_MASKED)) { + desc->status &= ~IRQ_MASKED; + desc->chip->unmask(irq); + } + spin_unlock_irq(&desc->lock); + chip_bus_sync_unlock(irq, desc); +} + #ifdef CONFIG_SMP /* * Check whether we need to change the affinity of the interrupt thread. @@ -492,7 +534,7 @@ static int irq_thread(void *data) 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; + int wake, oneshot = desc->status & IRQ_ONESHOT; sched_setscheduler(current, SCHED_FIFO, ¶m); current->irqaction = action; @@ -518,6 +560,9 @@ static int irq_thread(void *data) spin_unlock_irq(&desc->lock); action->thread_fn(action->irq, action->dev_id); + + if (oneshot) + irq_finalize_oneshot(action->irq, desc); } wake = atomic_dec_and_test(&desc->threads_active); @@ -565,7 +610,7 @@ __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 shared = 0; + int nested, shared = 0; int ret; if (!desc) @@ -590,10 +635,32 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) rand_initialize_irq(irq); } + /* Oneshot interrupts are not allowed with shared */ + if ((new->flags & IRQF_ONESHOT) && (new->flags & IRQF_SHARED)) + return -EINVAL; + + /* + * Check whether the interrupt nests into another interrupt + * thread. + */ + nested = desc->status & IRQ_NESTED_THREAD; + if (nested) { + if (!new->thread_fn) + return -EINVAL; + /* + * 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; + } + /* - * Threaded handler ? + * Create a handler thread when a thread function is supplied + * and the interrupt does not nest into another interrupt + * thread. */ - if (new->thread_fn) { + if (new->thread_fn && !nested) { struct task_struct *t; t = kthread_create(irq_thread, new, "irq/%d-%s", irq, @@ -662,9 +729,12 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) desc->status |= IRQ_PER_CPU; #endif - desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | + desc->status &= ~(IRQ_AUTODETECT | IRQ_WAITING | IRQ_ONESHOT | IRQ_INPROGRESS | IRQ_SPURIOUS_DISABLED); + if (new->flags & IRQF_ONESHOT) + desc->status |= IRQ_ONESHOT; + if (!(desc->status & IRQ_NOAUTOEN)) { desc->depth = 0; desc->status &= ~IRQ_DISABLED; @@ -875,7 +945,14 @@ EXPORT_SYMBOL_GPL(remove_irq); */ void free_irq(unsigned int irq, void *dev_id) { + struct irq_desc *desc = irq_to_desc(irq); + + if (!desc) + return; + + chip_bus_lock(irq, desc); kfree(__free_irq(irq, dev_id)); + chip_bus_sync_unlock(irq, desc); } EXPORT_SYMBOL(free_irq); @@ -884,6 +961,8 @@ EXPORT_SYMBOL(free_irq); * @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 @@ -963,8 +1042,12 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler, if (desc->status & IRQ_NOREQUEST) return -EINVAL; - if (!handler) - return -EINVAL; + + if (!handler) { + if (!thread_fn) + return -EINVAL; + handler = irq_default_primary_handler; + } action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); if (!action) @@ -976,7 +1059,10 @@ int request_threaded_irq(unsigned int irq, irq_handler_t handler, action->name = devname; action->dev_id = dev_id; + chip_bus_lock(irq, desc); retval = __setup_irq(irq, desc, action); + chip_bus_sync_unlock(irq, desc); + if (retval) kfree(action); |
