diff options
| -rw-r--r-- | include/linux/interrupt.h | 20 | ||||
| -rw-r--r-- | include/linux/irq.h | 2 | ||||
| -rw-r--r-- | kernel/irq/manage.c | 29 |
3 files changed, 49 insertions, 2 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index d9b05b5bf8c7..b95dc28f4cc3 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -57,6 +57,9 @@ * IRQF_NO_THREAD - Interrupt cannot be threaded * IRQF_EARLY_RESUME - Resume IRQ early during syscore instead of at device * resume time. + * __IRQF_NMI - Route the interrupt to an NMI or some similar signal that is not + * masked by local_irq_disable(). Used internally by + * request_nmi_irq(). */ #define IRQF_DISABLED 0x00000020 #define IRQF_SHARED 0x00000080 @@ -70,6 +73,7 @@ #define IRQF_FORCE_RESUME 0x00008000 #define IRQF_NO_THREAD 0x00010000 #define IRQF_EARLY_RESUME 0x00020000 +#define __IRQF_NMI 0x00040000 #define IRQF_TIMER (__IRQF_TIMER | IRQF_NO_SUSPEND | IRQF_NO_THREAD) @@ -139,6 +143,22 @@ extern int __must_check request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id); +static inline int __must_check request_nmi_irq(unsigned int irq, + unsigned long flags, + const char *name, void *dev_id) +{ + /* + * no_action unconditionally returns IRQ_NONE which is exactly + * what we need. The handler might be expected to be unreachable + * but some controllers may spuriously ack the NMI from the IRQ + * handling code. When this happens it occurs very rarely, thus + * by returning IRQ_NONE we can rely on the spurious interrupt + * logic to do the right thing. + */ + return request_irq(irq, no_action, flags | IRQF_NO_THREAD | __IRQF_NMI, + name, dev_id); +} + extern void free_irq(unsigned int, void *); extern void free_percpu_irq(unsigned int, void __percpu *); diff --git a/include/linux/irq.h b/include/linux/irq.h index d09ec7a1243e..695eb37f04ae 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -307,6 +307,7 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d) * @irq_eoi: end of interrupt * @irq_set_affinity: set the CPU affinity on SMP machines * @irq_retrigger: resend an IRQ to the CPU + * @irq_set_nmi_routing:set whether interrupt can act like NMI * @irq_set_type: set the flow type (IRQ_TYPE_LEVEL/etc.) of an IRQ * @irq_set_wake: enable/disable power-management wake-on of an IRQ * @irq_bus_lock: function to lock access to slow bus (i2c) chips @@ -341,6 +342,7 @@ struct irq_chip { int (*irq_set_affinity)(struct irq_data *data, const struct cpumask *dest, bool force); int (*irq_retrigger)(struct irq_data *data); + int (*irq_set_nmi_routing)(struct irq_data *data, unsigned int nmi); int (*irq_set_type)(struct irq_data *data, unsigned int flow_type); int (*irq_set_wake)(struct irq_data *data, unsigned int on); diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 80692373abd6..8e669051759d 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -571,6 +571,17 @@ int can_request_irq(unsigned int irq, unsigned long irqflags) return canrequest; } +int __irq_set_nmi_routing(struct irq_desc *desc, unsigned int irq, + unsigned int nmi) +{ + struct irq_chip *chip = desc->irq_data.chip; + + if (!chip || !chip->irq_set_nmi_routing) + return -EINVAL; + + return chip->irq_set_nmi_routing(&desc->irq_data, nmi); +} + int __irq_set_trigger(struct irq_desc *desc, unsigned int irq, unsigned long flags) { @@ -1058,11 +1069,12 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) * 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. + * agree on ONESHOT and NMI */ if (!((old->flags & new->flags) & IRQF_SHARED) || ((old->flags ^ new->flags) & IRQF_TRIGGER_MASK) || - ((old->flags ^ new->flags) & IRQF_ONESHOT)) + ((old->flags ^ new->flags) & IRQF_ONESHOT) || + ((old->flags ^ new->flags) & __IRQF_NMI)) goto mismatch; /* All handlers must agree on per-cpuness */ @@ -1153,6 +1165,19 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) init_waitqueue_head(&desc->wait_for_threads); + if (new->flags & __IRQF_NMI) { + ret = __irq_set_nmi_routing(desc, irq, true); + if (ret != 1) + goto out_mask; + } else { + ret = __irq_set_nmi_routing(desc, irq, false); + if (ret == 1) { + pr_err("Failed to disable NMI routing for irq %d\n", + irq); + goto out_mask; + } + } + /* Setup the type (level, edge polarity) if configured: */ if (new->flags & IRQF_TRIGGER_MASK) { ret = __irq_set_trigger(desc, irq, |