diff options
Diffstat (limited to 'kernel/irq')
| -rw-r--r-- | kernel/irq/chip.c | 35 | ||||
| -rw-r--r-- | kernel/irq/manage.c | 22 |
2 files changed, 46 insertions, 11 deletions
diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 42ec11b..b7091d5 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -359,6 +359,23 @@ static inline void mask_ack_irq(struct irq_desc *desc, int irq) if (desc->chip->ack) desc->chip->ack(irq); } + desc->status |= IRQ_MASKED; +} + +static inline void mask_irq(struct irq_desc *desc, int irq) +{ + if (desc->chip->mask) { + desc->chip->mask(irq); + desc->status |= IRQ_MASKED; + } +} + +static inline void unmask_irq(struct irq_desc *desc, int irq) +{ + if (desc->chip->unmask) { + desc->chip->unmask(irq); + desc->status &= ~IRQ_MASKED; + } } /* @@ -484,10 +501,8 @@ handle_level_irq(unsigned int irq, struct irq_desc *desc) raw_spin_lock(&desc->lock); desc->status &= ~IRQ_INPROGRESS; - if (unlikely(desc->status & IRQ_ONESHOT)) - desc->status |= IRQ_MASKED; - else if (!(desc->status & IRQ_DISABLED) && desc->chip->unmask) - desc->chip->unmask(irq); + if (!(desc->status & (IRQ_DISABLED | IRQ_ONESHOT))) + unmask_irq(desc, irq); out_unlock: raw_spin_unlock(&desc->lock); } @@ -524,8 +539,7 @@ handle_fasteoi_irq(unsigned int irq, struct irq_desc *desc) action = desc->action; if (unlikely(!action || (desc->status & IRQ_DISABLED))) { desc->status |= IRQ_PENDING; - if (desc->chip->mask) - desc->chip->mask(irq); + mask_irq(desc, irq); goto out; } @@ -593,7 +607,7 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc) irqreturn_t action_ret; if (unlikely(!action)) { - desc->chip->mask(irq); + mask_irq(desc, irq); goto out_unlock; } @@ -605,8 +619,7 @@ handle_edge_irq(unsigned int irq, struct irq_desc *desc) if (unlikely((desc->status & (IRQ_PENDING | IRQ_MASKED | IRQ_DISABLED)) == (IRQ_PENDING | IRQ_MASKED))) { - desc->chip->unmask(irq); - desc->status &= ~IRQ_MASKED; + unmask_irq(desc, irq); } desc->status &= ~IRQ_PENDING; @@ -716,7 +729,7 @@ set_irq_chip_and_handler_name(unsigned int irq, struct irq_chip *chip, __set_irq_handler(irq, handle, 0, name); } -void __init set_irq_noprobe(unsigned int irq) +void set_irq_noprobe(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; @@ -731,7 +744,7 @@ void __init set_irq_noprobe(unsigned int irq) raw_spin_unlock_irqrestore(&desc->lock, flags); } -void __init set_irq_probe(unsigned int irq) +void set_irq_probe(unsigned int irq) { struct irq_desc *desc = irq_to_desc(irq); unsigned long flags; diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index eb6078c..398fda15 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -382,6 +382,7 @@ int can_request_irq(unsigned int irq, unsigned long irqflags) { struct irq_desc *desc = irq_to_desc(irq); struct irqaction *action; + unsigned long flags; if (!desc) return 0; @@ -389,11 +390,14 @@ int can_request_irq(unsigned int irq, unsigned long irqflags) 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; } @@ -483,8 +487,26 @@ static int irq_wait_for_interrupt(struct irqaction *action) */ static void irq_finalize_oneshot(unsigned int irq, struct irq_desc *desc) { +again: chip_bus_lock(irq, 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 IRQ_INPROGRESS and the irq line is masked forever. + */ + if (unlikely(desc->status & IRQ_INPROGRESS)) { + raw_spin_unlock_irq(&desc->lock); + chip_bus_sync_unlock(irq, desc); + cpu_relax(); + goto again; + } + if (!(desc->status & IRQ_DISABLED) && (desc->status & IRQ_MASKED)) { desc->status &= ~IRQ_MASKED; desc->chip->unmask(irq); |
