diff options
| -rw-r--r-- | include/linux/interrupt.h | 9 | ||||
| -rw-r--r-- | include/linux/irq.h | 7 | ||||
| -rw-r--r-- | kernel/irq/debugfs.c | 6 | ||||
| -rw-r--r-- | kernel/irq/internals.h | 2 | ||||
| -rw-r--r-- | kernel/irq/manage.c | 228 |
5 files changed, 249 insertions, 3 deletions
diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index c672f34235e7..9941d1a8d83c 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -156,6 +156,10 @@ __request_percpu_irq(unsigned int irq, irq_handler_t handler, unsigned long flags, const char *devname, void __percpu *percpu_dev_id); +extern int __must_check +request_nmi(unsigned int irq, irq_handler_t handler, unsigned long flags, + const char *name, void *dev); + static inline int __must_check request_percpu_irq(unsigned int irq, irq_handler_t handler, const char *devname, void __percpu *percpu_dev_id) @@ -167,6 +171,8 @@ request_percpu_irq(unsigned int irq, irq_handler_t handler, extern const void *free_irq(unsigned int, void *); extern void free_percpu_irq(unsigned int, void __percpu *); +extern const void *free_nmi(unsigned int irq, void *dev_id); + struct device; extern int __must_check @@ -217,6 +223,9 @@ extern void enable_percpu_irq(unsigned int irq, unsigned int type); extern bool irq_percpu_is_enabled(unsigned int irq); extern void irq_wake_thread(unsigned int irq, void *dev_id); +extern void disable_nmi_nosync(unsigned int irq); +extern void enable_nmi(unsigned int irq); + /* The following three functions are for the core kernel use only. */ extern void suspend_device_irqs(void); extern void resume_device_irqs(void); diff --git a/include/linux/irq.h b/include/linux/irq.h index def2b2aac8b1..a7298e4998c8 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -442,6 +442,8 @@ static inline irq_hw_number_t irqd_to_hwirq(struct irq_data *d) * @irq_set_vcpu_affinity: optional to target a vCPU in a virtual machine * @ipi_send_single: send a single IPI to destination cpus * @ipi_send_mask: send an IPI to destination cpus in cpumask + * @irq_nmi_setup: function called from core code before enabling an NMI + * @irq_nmi_teardown: function called from core code after disabling an NMI * @flags: chip specific flags */ struct irq_chip { @@ -490,6 +492,9 @@ struct irq_chip { void (*ipi_send_single)(struct irq_data *data, unsigned int cpu); void (*ipi_send_mask)(struct irq_data *data, const struct cpumask *dest); + int (*irq_nmi_setup)(struct irq_data *data); + void (*irq_nmi_teardown)(struct irq_data *data); + unsigned long flags; }; @@ -505,6 +510,7 @@ struct irq_chip { * IRQCHIP_ONESHOT_SAFE: One shot does not require mask/unmask * IRQCHIP_EOI_THREADED: Chip requires eoi() on unmask in threaded mode * IRQCHIP_SUPPORTS_LEVEL_MSI Chip can provide two doorbells for Level MSIs + * IRQCHIP_SUPPORTS_NMI: Chip can deliver NMIs, only for root irqchips */ enum { IRQCHIP_SET_TYPE_MASKED = (1 << 0), @@ -515,6 +521,7 @@ enum { IRQCHIP_ONESHOT_SAFE = (1 << 5), IRQCHIP_EOI_THREADED = (1 << 6), IRQCHIP_SUPPORTS_LEVEL_MSI = (1 << 7), + IRQCHIP_SUPPORTS_NMI = (1 << 8), }; #include <linux/irqdesc.h> diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c index 6f636136cccc..59a04d2a66df 100644 --- a/kernel/irq/debugfs.c +++ b/kernel/irq/debugfs.c @@ -56,6 +56,7 @@ static const struct irq_bit_descr irqchip_flags[] = { BIT_MASK_DESCR(IRQCHIP_ONESHOT_SAFE), BIT_MASK_DESCR(IRQCHIP_EOI_THREADED), BIT_MASK_DESCR(IRQCHIP_SUPPORTS_LEVEL_MSI), + BIT_MASK_DESCR(IRQCHIP_SUPPORTS_NMI), }; static void @@ -140,6 +141,7 @@ static const struct irq_bit_descr irqdesc_istates[] = { BIT_MASK_DESCR(IRQS_WAITING), BIT_MASK_DESCR(IRQS_PENDING), BIT_MASK_DESCR(IRQS_SUSPENDED), + BIT_MASK_DESCR(IRQS_NMI), }; @@ -203,8 +205,8 @@ static ssize_t irq_debug_write(struct file *file, const char __user *user_buf, chip_bus_lock(desc); raw_spin_lock_irqsave(&desc->lock, flags); - if (irq_settings_is_level(desc)) { - /* Can't do level, sorry */ + if (irq_settings_is_level(desc) || desc->istate & IRQS_NMI) { + /* Can't do level nor NMIs, sorry */ err = -EINVAL; } else { desc->istate |= IRQS_PENDING; diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index ca6afa267070..2a77cdd27ca9 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -49,6 +49,7 @@ enum { * IRQS_WAITING - irq is waiting * IRQS_PENDING - irq is pending and replayed later * IRQS_SUSPENDED - irq is suspended + * IRQS_NMI - irq line is used to deliver NMIs */ enum { IRQS_AUTODETECT = 0x00000001, @@ -60,6 +61,7 @@ enum { IRQS_PENDING = 0x00000200, IRQS_SUSPENDED = 0x00000800, IRQS_TIMINGS = 0x00001000, + IRQS_NMI = 0x00002000, }; #include "debug.h" diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index a4888ce4667a..9472ae987946 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -341,7 +341,7 @@ irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify) /* The release function is promised process context */ might_sleep(); - if (!desc) + if (!desc || desc->istate & IRQS_NMI) return -EINVAL; /* Complete initialisation of *notify */ @@ -550,6 +550,21 @@ bool disable_hardirq(unsigned int irq) } EXPORT_SYMBOL_GPL(disable_hardirq); +/** + * disable_nmi_nosync - disable an nmi without waiting + * @irq: Interrupt to disable + * + * Disable the selected interrupt line. Disables and enables are + * nested. + * The interrupt to disable must have been requested through request_nmi. + * Unlike disable_nmi(), this function does not ensure existing + * instances of the IRQ handler have completed before returning. + */ +void disable_nmi_nosync(unsigned int irq) +{ + disable_irq_nosync(irq); +} + void __enable_irq(struct irq_desc *desc) { switch (desc->depth) { @@ -606,6 +621,20 @@ out: } EXPORT_SYMBOL(enable_irq); +/** + * enable_nmi - enable handling of an nmi + * @irq: Interrupt to enable + * + * The interrupt to enable must have been requested through request_nmi. + * Undoes the effect of one call to disable_nmi(). If this + * matches the last disable, processing of interrupts on this + * IRQ line is re-enabled. + */ +void enable_nmi(unsigned int irq) +{ + enable_irq(irq); +} + static int set_irq_wake_real(unsigned int irq, unsigned int on) { struct irq_desc *desc = irq_to_desc(irq); @@ -641,6 +670,12 @@ int irq_set_irq_wake(unsigned int irq, unsigned int on) if (!desc) return -EINVAL; + /* Don't use NMIs as wake up interrupts please */ + if (desc->istate & IRQS_NMI) { + ret = -EINVAL; + goto out_unlock; + } + /* wakeup-capable irqs can be shared between drivers that * don't need to have the same sleep mode behaviors. */ @@ -663,6 +698,8 @@ int irq_set_irq_wake(unsigned int irq, unsigned int on) irqd_clear(&desc->irq_data, IRQD_WAKEUP_STATE); } } + +out_unlock: irq_put_desc_busunlock(desc, flags); return ret; } @@ -1125,6 +1162,39 @@ static void irq_release_resources(struct irq_desc *desc) c->irq_release_resources(d); } +static bool irq_supports_nmi(struct irq_desc *desc) +{ + struct irq_data *d = irq_desc_get_irq_data(desc); + +#ifdef CONFIG_IRQ_DOMAIN_HIERARCHY + /* Only IRQs directly managed by the root irqchip can be set as NMI */ + if (d->parent_data) + return false; +#endif + /* Don't support NMIs for chips behind a slow bus */ + if (d->chip->irq_bus_lock || d->chip->irq_bus_sync_unlock) + return false; + + return d->chip->flags & IRQCHIP_SUPPORTS_NMI; +} + +static int irq_nmi_setup(struct irq_desc *desc) +{ + struct irq_data *d = irq_desc_get_irq_data(desc); + struct irq_chip *c = d->chip; + + return c->irq_nmi_setup ? c->irq_nmi_setup(d) : -EINVAL; +} + +static void irq_nmi_teardown(struct irq_desc *desc) +{ + struct irq_data *d = irq_desc_get_irq_data(desc); + struct irq_chip *c = d->chip; + + if (c->irq_nmi_teardown) + c->irq_nmi_teardown(d); +} + static int setup_irq_thread(struct irqaction *new, unsigned int irq, bool secondary) { @@ -1299,9 +1369,17 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) * fields must have IRQF_SHARED set and the bits which * set the trigger type must match. Also all must * agree on ONESHOT. + * Interrupt lines used for NMIs cannot be shared. */ unsigned int oldtype; + if (desc->istate & IRQS_NMI) { + pr_err("Invalid attempt to share NMI for %s (irq %d) on irqchip %s.\n", + new->name, irq, desc->irq_data.chip->name); + ret = -EINVAL; + goto out_unlock; + } + /* * If nobody did set the configuration before, inherit * the one provided by the requester. @@ -1753,6 +1831,59 @@ const void *free_irq(unsigned int irq, void *dev_id) } EXPORT_SYMBOL(free_irq); +/* This function must be called with desc->lock held */ +static const void *__cleanup_nmi(unsigned int irq, struct irq_desc *desc) +{ + const char *devname = NULL; + + desc->istate &= ~IRQS_NMI; + + if (!WARN_ON(desc->action == NULL)) { + irq_pm_remove_action(desc, desc->action); + devname = desc->action->name; + unregister_handler_proc(irq, desc->action); + + kfree(desc->action); + desc->action = NULL; + } + + irq_settings_clr_disable_unlazy(desc); + irq_shutdown(desc); + + irq_release_resources(desc); + + irq_chip_pm_put(&desc->irq_data); + module_put(desc->owner); + + return devname; +} + +const void *free_nmi(unsigned int irq, void *dev_id) +{ + struct irq_desc *desc = irq_to_desc(irq); + unsigned long flags; + const void *devname; + + if (!desc || WARN_ON(!(desc->istate & IRQS_NMI))) + return NULL; + + if (WARN_ON(irq_settings_is_per_cpu_devid(desc))) + return NULL; + + /* NMI still enabled */ + if (WARN_ON(desc->depth == 0)) + disable_nmi_nosync(irq); + + raw_spin_lock_irqsave(&desc->lock, flags); + + irq_nmi_teardown(desc); + devname = __cleanup_nmi(irq, desc); + + raw_spin_unlock_irqrestore(&desc->lock, flags); + + return devname; +} + /** * request_threaded_irq - allocate an interrupt line * @irq: Interrupt line to allocate @@ -1922,6 +2053,101 @@ int request_any_context_irq(unsigned int irq, irq_handler_t handler, } EXPORT_SYMBOL_GPL(request_any_context_irq); +/** + * request_nmi - allocate an interrupt line for NMI delivery + * @irq: Interrupt line to allocate + * @handler: Function to be called when the IRQ occurs. + * Threaded handler for threaded interrupts. + * @irqflags: 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 sets up the IRQ line + * to be handled as an NMI. + * + * An interrupt line delivering NMIs cannot be shared and IRQ handling + * cannot be threaded. + * + * Interrupt lines requested for NMI delivering must produce per cpu + * interrupts and have auto enabling setting disabled. + * + * 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 the interrupt line cannot be used to deliver NMIs, function + * will fail and return a negative value. + */ +int request_nmi(unsigned int irq, irq_handler_t handler, + unsigned long irqflags, const char *name, void *dev_id) +{ + struct irqaction *action; + struct irq_desc *desc; + unsigned long flags; + int retval; + + if (irq == IRQ_NOTCONNECTED) + return -ENOTCONN; + + /* NMI cannot be shared, used for Polling */ + if (irqflags & (IRQF_SHARED | IRQF_COND_SUSPEND | IRQF_IRQPOLL)) + return -EINVAL; + + if (!(irqflags & IRQF_PERCPU)) + return -EINVAL; + + if (!handler) + return -EINVAL; + + desc = irq_to_desc(irq); + + if (!desc || irq_settings_can_autoenable(desc) || + !irq_settings_can_request(desc) || + WARN_ON(irq_settings_is_per_cpu_devid(desc)) || + !irq_supports_nmi(desc)) + return -EINVAL; + + action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); + if (!action) + return -ENOMEM; + + action->handler = handler; + action->flags = irqflags | IRQF_NO_THREAD | IRQF_NOBALANCING; + action->name = name; + action->dev_id = dev_id; + + retval = irq_chip_pm_get(&desc->irq_data); + if (retval < 0) + goto err_out; + + retval = __setup_irq(irq, desc, action); + if (retval) + goto err_irq_setup; + + raw_spin_lock_irqsave(&desc->lock, flags); + + /* Setup NMI state */ + desc->istate |= IRQS_NMI; + retval = irq_nmi_setup(desc); + if (retval) { + __cleanup_nmi(irq, desc); + raw_spin_unlock_irqrestore(&desc->lock, flags); + return -EINVAL; + } + + raw_spin_unlock_irqrestore(&desc->lock, flags); + + return 0; + +err_irq_setup: + irq_chip_pm_put(&desc->irq_data); +err_out: + kfree(action); + + return retval; +} + void enable_percpu_irq(unsigned int irq, unsigned int type) { unsigned int cpu = smp_processor_id(); |