From 9114014cf4e6df0b22d764380ae1fc54f1a7a8b2 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Thu, 29 Jun 2017 23:33:37 +0200 Subject: genirq: Add mutex to irq desc to serialize request/free_irq() The irq_request/release_resources() callbacks ar currently invoked under desc->lock with interrupts disabled. This is a source of problems on RT and conceptually not required. Add a seperate mutex to struct irq_desc which allows to serialize request/free_irq(), which can be used to move the resource functions out of the desc->lock held region. Signed-off-by: Thomas Gleixner Reviewed-by: Marc Zyngier Cc: Heiko Stuebner Cc: Julia Cartwright Cc: Linus Walleij Cc: Brian Norris Cc: Doug Anderson Cc: linux-rockchip@lists.infradead.org Cc: John Keeping Cc: linux-gpio@vger.kernel.org Link: http://lkml.kernel.org/r/20170629214344.039220922@linutronix.de --- kernel/irq/irqdesc.c | 1 + kernel/irq/manage.c | 8 ++++++++ 2 files changed, 9 insertions(+) (limited to 'kernel/irq') diff --git a/kernel/irq/irqdesc.c b/kernel/irq/irqdesc.c index 948b50e78549..906a67e58391 100644 --- a/kernel/irq/irqdesc.c +++ b/kernel/irq/irqdesc.c @@ -373,6 +373,7 @@ static struct irq_desc *alloc_desc(int irq, int node, unsigned int flags, raw_spin_lock_init(&desc->lock); lockdep_set_class(&desc->lock, &irq_desc_lock_class); + mutex_init(&desc->request_mutex); init_rcu_head(&desc->rcu); desc_set_defaults(irq, desc, node, affinity, owner); diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 0934e02fa04e..0139908b8d53 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -1167,6 +1167,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE) new->flags &= ~IRQF_ONESHOT; + mutex_lock(&desc->request_mutex); + chip_bus_lock(desc); /* @@ -1350,6 +1352,7 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new) raw_spin_unlock_irqrestore(&desc->lock, flags); chip_bus_sync_unlock(desc); + mutex_unlock(&desc->request_mutex); irq_setup_timings(desc, new); @@ -1383,6 +1386,8 @@ out_unlock: chip_bus_sync_unlock(desc); + mutex_unlock(&desc->request_mutex); + out_thread: if (new->thread) { struct task_struct *t = new->thread; @@ -1446,6 +1451,7 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) if (!desc) return NULL; + mutex_lock(&desc->request_mutex); chip_bus_lock(desc); raw_spin_lock_irqsave(&desc->lock, flags); @@ -1521,6 +1527,8 @@ static struct irqaction *__free_irq(unsigned int irq, void *dev_id) } } + mutex_unlock(&desc->request_mutex); + irq_chip_pm_put(&desc->irq_data); module_put(desc->owner); kfree(action->secondary); -- cgit