From b525903c254dab2491410f0f23707691b7c2c317 Mon Sep 17 00:00:00 2001 From: Julien Thierry Date: Thu, 31 Jan 2019 14:53:58 +0000 Subject: genirq: Provide basic NMI management for interrupt lines Add functionality to allocate interrupt lines that will deliver IRQs as Non-Maskable Interrupts. These allocations are only successful if the irqchip provides the necessary support and allows NMI delivery for the interrupt line. Interrupt lines allocated for NMI delivery must be enabled/disabled through enable_nmi/disable_nmi_nosync to keep their state consistent. To treat a PERCPU IRQ as NMI, the interrupt must not be shared nor threaded, the irqchip directly managing the IRQ must be the root irqchip and the irqchip cannot be behind a slow bus. Signed-off-by: Julien Thierry Reviewed-by: Marc Zyngier Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Marc Zyngier Signed-off-by: Marc Zyngier --- kernel/irq/debugfs.c | 6 +- kernel/irq/internals.h | 2 + kernel/irq/manage.c | 228 ++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 233 insertions(+), 3 deletions(-) (limited to 'kernel/irq') 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(); -- cgit From 4b078c3f1a26487c39363089ba0d5c6b09f2a89f Mon Sep 17 00:00:00 2001 From: Julien Thierry Date: Thu, 31 Jan 2019 14:53:59 +0000 Subject: genirq: Provide NMI management for percpu_devid interrupts Add support for percpu_devid interrupts treated as NMIs. Percpu_devid NMIs need to be setup/torn down on each CPU they target. The same restrictions as for global NMIs still apply for percpu_devid NMIs. Signed-off-by: Julien Thierry Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Marc Zyngier Signed-off-by: Marc Zyngier --- kernel/irq/manage.c | 177 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 177 insertions(+) (limited to 'kernel/irq') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 9472ae987946..0a1ebc004a59 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -2182,6 +2182,11 @@ out: } EXPORT_SYMBOL_GPL(enable_percpu_irq); +void enable_percpu_nmi(unsigned int irq, unsigned int type) +{ + enable_percpu_irq(irq, type); +} + /** * irq_percpu_is_enabled - Check whether the per cpu irq is enabled * @irq: Linux irq number to check for @@ -2221,6 +2226,11 @@ void disable_percpu_irq(unsigned int irq) } EXPORT_SYMBOL_GPL(disable_percpu_irq); +void disable_percpu_nmi(unsigned int irq) +{ + disable_percpu_irq(irq); +} + /* * Internal function to unregister a percpu irqaction. */ @@ -2252,6 +2262,8 @@ static struct irqaction *__free_percpu_irq(unsigned int irq, void __percpu *dev_ /* Found it - now remove it from the list of entries: */ desc->action = NULL; + desc->istate &= ~IRQS_NMI; + raw_spin_unlock_irqrestore(&desc->lock, flags); unregister_handler_proc(irq, action); @@ -2305,6 +2317,19 @@ void free_percpu_irq(unsigned int irq, void __percpu *dev_id) } EXPORT_SYMBOL_GPL(free_percpu_irq); +void free_percpu_nmi(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; + + if (WARN_ON(!(desc->istate & IRQS_NMI))) + return; + + kfree(__free_percpu_irq(irq, dev_id)); +} + /** * setup_percpu_irq - setup a per-cpu interrupt * @irq: Interrupt line to setup @@ -2394,6 +2419,158 @@ int __request_percpu_irq(unsigned int irq, irq_handler_t handler, } EXPORT_SYMBOL_GPL(__request_percpu_irq); +/** + * request_percpu_nmi - allocate a percpu interrupt line for NMI delivery + * @irq: Interrupt line to allocate + * @handler: Function to be called when the IRQ occurs. + * @name: An ascii name for the claiming device + * @dev_id: A percpu cookie passed back to the handler function + * + * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs + * have to be setup on each CPU by calling ready_percpu_nmi() before being + * enabled on the same CPU by using enable_percpu_nmi(). + * + * 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. + * + * Interrupt lines requested for NMI delivering should have auto enabling + * setting disabled. + * + * If the interrupt line cannot be used to deliver NMIs, function + * will fail returning a negative value. + */ +int request_percpu_nmi(unsigned int irq, irq_handler_t handler, + const char *name, void __percpu *dev_id) +{ + struct irqaction *action; + struct irq_desc *desc; + unsigned long flags; + int retval; + + if (!handler) + return -EINVAL; + + desc = irq_to_desc(irq); + + if (!desc || !irq_settings_can_request(desc) || + !irq_settings_is_per_cpu_devid(desc) || + irq_settings_can_autoenable(desc) || + !irq_supports_nmi(desc)) + return -EINVAL; + + /* The line cannot already be NMI */ + if (desc->istate & IRQS_NMI) + return -EINVAL; + + action = kzalloc(sizeof(struct irqaction), GFP_KERNEL); + if (!action) + return -ENOMEM; + + action->handler = handler; + action->flags = IRQF_PERCPU | IRQF_NO_SUSPEND | IRQF_NO_THREAD + | IRQF_NOBALANCING; + action->name = name; + action->percpu_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); + desc->istate |= IRQS_NMI; + 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; +} + +/** + * prepare_percpu_nmi - performs CPU local setup for NMI delivery + * @irq: Interrupt line to prepare for NMI delivery + * + * This call prepares an interrupt line to deliver NMI on the current CPU, + * before that interrupt line gets enabled with enable_percpu_nmi(). + * + * As a CPU local operation, this should be called from non-preemptible + * context. + * + * If the interrupt line cannot be used to deliver NMIs, function + * will fail returning a negative value. + */ +int prepare_percpu_nmi(unsigned int irq) +{ + unsigned long flags; + struct irq_desc *desc; + int ret = 0; + + WARN_ON(preemptible()); + + desc = irq_get_desc_lock(irq, &flags, + IRQ_GET_DESC_CHECK_PERCPU); + if (!desc) + return -EINVAL; + + if (WARN(!(desc->istate & IRQS_NMI), + KERN_ERR "prepare_percpu_nmi called for a non-NMI interrupt: irq %u\n", + irq)) { + ret = -EINVAL; + goto out; + } + + ret = irq_nmi_setup(desc); + if (ret) { + pr_err("Failed to setup NMI delivery: irq %u\n", irq); + goto out; + } + +out: + irq_put_desc_unlock(desc, flags); + return ret; +} + +/** + * teardown_percpu_nmi - undoes NMI setup of IRQ line + * @irq: Interrupt line from which CPU local NMI configuration should be + * removed + * + * This call undoes the setup done by prepare_percpu_nmi(). + * + * IRQ line should not be enabled for the current CPU. + * + * As a CPU local operation, this should be called from non-preemptible + * context. + */ +void teardown_percpu_nmi(unsigned int irq) +{ + unsigned long flags; + struct irq_desc *desc; + + WARN_ON(preemptible()); + + desc = irq_get_desc_lock(irq, &flags, + IRQ_GET_DESC_CHECK_PERCPU); + if (!desc) + return; + + if (WARN_ON(!(desc->istate & IRQS_NMI))) + goto out; + + irq_nmi_teardown(desc); +out: + irq_put_desc_unlock(desc, flags); +} + /** * irq_get_irqchip_state - returns the irqchip state of a interrupt. * @irq: Interrupt line that is forwarded to a VM -- cgit From 2dcf1fbcad352baaa5f47b17e57c5743c8eedbad Mon Sep 17 00:00:00 2001 From: Julien Thierry Date: Thu, 31 Jan 2019 14:54:00 +0000 Subject: genirq: Provide NMI handlers Provide flow handlers that are NMI safe for interrupts and percpu_devid interrupts. Signed-off-by: Julien Thierry Acked-by: Marc Zyngier Cc: Thomas Gleixner Cc: Marc Zyngier Cc: Peter Zijlstra Signed-off-by: Marc Zyngier --- kernel/irq/chip.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) (limited to 'kernel/irq') diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 34e969069488..c32d5f386f68 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -729,6 +729,37 @@ out: } EXPORT_SYMBOL_GPL(handle_fasteoi_irq); +/** + * handle_fasteoi_nmi - irq handler for NMI interrupt lines + * @desc: the interrupt description structure for this irq + * + * A simple NMI-safe handler, considering the restrictions + * from request_nmi. + * + * Only a single callback will be issued to the chip: an ->eoi() + * call when the interrupt has been serviced. This enables support + * for modern forms of interrupt handlers, which handle the flow + * details in hardware, transparently. + */ +void handle_fasteoi_nmi(struct irq_desc *desc) +{ + struct irq_chip *chip = irq_desc_get_chip(desc); + struct irqaction *action = desc->action; + unsigned int irq = irq_desc_get_irq(desc); + irqreturn_t res; + + trace_irq_handler_entry(irq, action); + /* + * NMIs cannot be shared, there is only one action. + */ + res = action->handler(irq, action->dev_id); + trace_irq_handler_exit(irq, action, res); + + if (chip->irq_eoi) + chip->irq_eoi(&desc->irq_data); +} +EXPORT_SYMBOL_GPL(handle_fasteoi_nmi); + /** * handle_edge_irq - edge type IRQ handler * @desc: the interrupt description structure for this irq @@ -908,6 +939,29 @@ void handle_percpu_devid_irq(struct irq_desc *desc) chip->irq_eoi(&desc->irq_data); } +/** + * handle_percpu_devid_fasteoi_nmi - Per CPU local NMI handler with per cpu + * dev ids + * @desc: the interrupt description structure for this irq + * + * Similar to handle_fasteoi_nmi, but handling the dev_id cookie + * as a percpu pointer. + */ +void handle_percpu_devid_fasteoi_nmi(struct irq_desc *desc) +{ + struct irq_chip *chip = irq_desc_get_chip(desc); + struct irqaction *action = desc->action; + unsigned int irq = irq_desc_get_irq(desc); + irqreturn_t res; + + trace_irq_handler_entry(irq, action); + res = action->handler(irq, raw_cpu_ptr(action->percpu_dev_id)); + trace_irq_handler_exit(irq, action, res); + + if (chip->irq_eoi) + chip->irq_eoi(&desc->irq_data); +} + static void __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle, int is_chained, const char *name) -- cgit From 6e4933a006616343f66c4702dc4fc56bb25e7b02 Mon Sep 17 00:00:00 2001 From: Julien Thierry Date: Thu, 31 Jan 2019 14:54:01 +0000 Subject: irqdesc: Add domain handler for NMIs NMI handling code should be executed between calls to nmi_enter and nmi_exit. Add a separate domain handler to properly setup NMI context when handling an interrupt requested as NMI. Signed-off-by: Julien Thierry Acked-by: Marc Zyngier Cc: Thomas Gleixner Cc: Marc Zyngier Cc: Will Deacon Cc: Peter Zijlstra Signed-off-by: Marc Zyngier --- kernel/irq/irqdesc.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) (limited to 'kernel/irq') diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index ee062b7939d3..a1d7a7d484e0 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -669,6 +669,41 @@ int __handle_domain_irq(struct irq_domain *domain, unsigned int hwirq, set_irq_regs(old_regs); return ret; } + +#ifdef CONFIG_IRQ_DOMAIN +/** + * handle_domain_nmi - Invoke the handler for a HW irq belonging to a domain + * @domain: The domain where to perform the lookup + * @hwirq: The HW irq number to convert to a logical one + * @regs: Register file coming from the low-level handling code + * + * Returns: 0 on success, or -EINVAL if conversion has failed + */ +int handle_domain_nmi(struct irq_domain *domain, unsigned int hwirq, + struct pt_regs *regs) +{ + struct pt_regs *old_regs = set_irq_regs(regs); + unsigned int irq; + int ret = 0; + + nmi_enter(); + + irq = irq_find_mapping(domain, hwirq); + + /* + * ack_bad_irq is not NMI-safe, just report + * an invalid interrupt. + */ + if (likely(irq)) + generic_handle_irq(irq); + else + ret = -EINVAL; + + nmi_exit(); + set_irq_regs(old_regs); + return ret; +} +#endif #endif /* Dynamic interrupt handling */ -- cgit From a51866946c0aa0b04a554595d38b496e80c76a1b Mon Sep 17 00:00:00 2001 From: Julien Thierry Date: Wed, 13 Feb 2019 10:09:19 +0000 Subject: genirq: Fix wrong name in request_percpu_nmi() description ready_percpu_nmi() was the previous name of prepare_percpu_nmi(). Update request_percpu_nmi() comment with the correct function name. Signed-off-by: Julien Thierry Reported-by: Li Wei Cc: Thomas Gleixner Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Marc Zyngier Signed-off-by: Marc Zyngier --- kernel/irq/manage.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel/irq') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 0a1ebc004a59..5b570050b9b6 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -2427,8 +2427,8 @@ EXPORT_SYMBOL_GPL(__request_percpu_irq); * @dev_id: A percpu cookie passed back to the handler function * * This call allocates interrupt resources for a per CPU NMI. Per CPU NMIs - * have to be setup on each CPU by calling ready_percpu_nmi() before being - * enabled on the same CPU by using enable_percpu_nmi(). + * have to be setup on each CPU by calling prepare_percpu_nmi() before + * being enabled on the same CPU by using enable_percpu_nmi(). * * Dev_id must be globally unique. It is a per-cpu variable, and * the handler gets called with the interrupted CPU's instance of -- cgit From 9f199dd34ce06f603df365ab18bd84eefc5f7c2b Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 20 Feb 2019 08:59:23 +0000 Subject: irqdomain: Allow the default irq domain to be retrieved The default irq domain allows legacy code to create irqdomain mappings without having to track the domain it is allocating from. Setting the default domain is a one shot, fire and forget operation, and no effort was made to be able to retrieve this information at a later point in time. Newer irqdomain APIs (the hierarchical stuff) relies on both the irqchip code to track the irqdomain it is allocating from, as well as some form of firmware abstraction to easily identify which piece of HW maps to which irq domain (DT, ACPI). For systems without such firmware (or legacy platform that are getting dragged into the 21st century), things are a bit harder. For these cases (and these cases only!), let's provide a way to retrieve the default domain, allowing the use of the v2 API without having to resort to platform-specific hacks. Signed-off-by: Marc Zyngier --- kernel/irq/irqdomain.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'kernel/irq') diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index 8b0be4bd6565..80818764643d 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -458,6 +458,20 @@ void irq_set_default_host(struct irq_domain *domain) } EXPORT_SYMBOL_GPL(irq_set_default_host); +/** + * irq_get_default_host() - Retrieve the "default" irq domain + * + * Returns: the default domain, if any. + * + * Modern code should never use this. This should only be used on + * systems that cannot implement a firmware->fwnode mapping (which + * both DT and ACPI provide). + */ +struct irq_domain *irq_get_default_host(void) +{ + return irq_default_domain; +} + static void irq_domain_clear_mapping(struct irq_domain *domain, irq_hw_number_t hwirq) { -- cgit