From 4cde9c6b826834b861a2b58653ab33150f562064 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Tue, 20 Jun 2017 01:37:49 +0200 Subject: [PATCH] genirq: Add force argument to irq_startup() In order to handle managed interrupts gracefully on irq_startup() so they won't lose their assigned affinity, it's necessary to allow startups which keep the interrupts in managed shutdown state, if none of the assigend CPUs is online. This allows drivers to request interrupts w/o the CPUs being online, which avoid online/offline churn in drivers. Add a force argument which can override that decision and let only request_irq() and enable_irq() allow the managed shutdown handling. enable_irq() is required, because the interrupt might be requested with IRQF_NOAUTOEN and enable_irq() invokes irq_startup() which would then wreckage the assignment again. All other callers force startup and potentially break the assigned affinity. No functional change as this only adds the function argument. Signed-off-by: Thomas Gleixner Cc: Jens Axboe Cc: Marc Zyngier Cc: Michael Ellerman Cc: Keith Busch Cc: Peter Zijlstra Cc: Christoph Hellwig Link: http://lkml.kernel.org/r/20170619235447.112094565@linutronix.de --- kernel/irq/autoprobe.c | 4 ++-- kernel/irq/chip.c | 4 ++-- kernel/irq/internals.h | 9 ++++++++- kernel/irq/manage.c | 4 ++-- 4 files changed, 14 insertions(+), 7 deletions(-) diff --git a/kernel/irq/autoprobe.c b/kernel/irq/autoprobe.c index 0119b9d467ae..d30a0dd5cc02 100644 --- a/kernel/irq/autoprobe.c +++ b/kernel/irq/autoprobe.c @@ -53,7 +53,7 @@ unsigned long probe_irq_on(void) if (desc->irq_data.chip->irq_set_type) desc->irq_data.chip->irq_set_type(&desc->irq_data, IRQ_TYPE_PROBE); - irq_startup(desc, false); + irq_startup(desc, IRQ_NORESEND, IRQ_START_FORCE); } raw_spin_unlock_irq(&desc->lock); } @@ -70,7 +70,7 @@ unsigned long probe_irq_on(void) raw_spin_lock_irq(&desc->lock); if (!desc->action && irq_settings_can_probe(desc)) { desc->istate |= IRQS_AUTODETECT | IRQS_WAITING; - if (irq_startup(desc, false)) + if (irq_startup(desc, IRQ_NORESEND, IRQ_START_FORCE)) desc->istate |= IRQS_PENDING; } raw_spin_unlock_irq(&desc->lock); diff --git a/kernel/irq/chip.c b/kernel/irq/chip.c index 1163089aa245..b7599e952d3b 100644 --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -212,7 +212,7 @@ static int __irq_startup(struct irq_desc *desc) return ret; } -int irq_startup(struct irq_desc *desc, bool resend) +int irq_startup(struct irq_desc *desc, bool resend, bool force) { int ret = 0; @@ -892,7 +892,7 @@ __irq_do_set_handler(struct irq_desc *desc, irq_flow_handler_t handle, irq_settings_set_norequest(desc); irq_settings_set_nothread(desc); desc->action = &chained_action; - irq_startup(desc, true); + irq_startup(desc, IRQ_RESEND, IRQ_START_FORCE); } } diff --git a/kernel/irq/internals.h b/kernel/irq/internals.h index ca4666b4cd39..5fd105e252c3 100644 --- a/kernel/irq/internals.h +++ b/kernel/irq/internals.h @@ -66,7 +66,14 @@ extern int __irq_set_trigger(struct irq_desc *desc, unsigned long flags); extern void __disable_irq(struct irq_desc *desc); extern void __enable_irq(struct irq_desc *desc); -extern int irq_startup(struct irq_desc *desc, bool resend); +#define IRQ_RESEND true +#define IRQ_NORESEND false + +#define IRQ_START_FORCE true +#define IRQ_START_COND false + +extern int irq_startup(struct irq_desc *desc, bool resend, bool force); + extern void irq_shutdown(struct irq_desc *desc); extern void irq_enable(struct irq_desc *desc); extern void irq_disable(struct irq_desc *desc); diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 7dcf19397c39..3577c091ac7b 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -509,7 +509,7 @@ void __enable_irq(struct irq_desc *desc) * time. If it was already started up, then irq_startup() * will invoke irq_enable() under the hood. */ - irq_startup(desc, true); + irq_startup(desc, IRQ_RESEND, IRQ_START_COND); break; } default: @@ -1306,7 +1306,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) } if (irq_settings_can_autoenable(desc)) { - irq_startup(desc, true); + irq_startup(desc, IRQ_RESEND, IRQ_START_COND); } else { /* * Shared interrupts do not go well with disabling