| Message ID | 1404825038-547-3-git-send-email-marc.zyngier@arm.com |
|---|---|
| State | New |
| Headers | show |
On Tue, Jul 08, 2014 at 02:10:25PM +0100, Marc Zyngier wrote: > Calling irq_find_mapping from outside a irq_{enter,exit} section is > unsafe and produces ugly messages if CONFIG_PROVE_RCU is enabled: > If coming from the idle state, the rcu_read_lock call in irq_find_mapping > will generate an an unpleasant warning. > > A solution is to add a new handle_domain_irq entry point into > the arm code that the interrupt controller code can call. > This new function takes an irq_domain, and calls into irq_find_domain > inside the irq_{enter,exit} block. > > Interrupt controllers can then be updated to use the new mechanism. I merged this last night, and this says it all... Subject: rmk build: 244 warnings 49 failures (rmk/v3.16-rc3-70-gc1ed1df) arch/arm/kernel/irq.c:81:3: error: implicit declaration of function 'irq_find_mapping' [-Werror=implicit-function-declaration] So I'm dropping it.
Hi Russell, On Sat, Aug 02 2014 at 8:51:18 am BST, Russell King - ARM Linux <linux@arm.linux.org.uk> wrote: > On Tue, Jul 08, 2014 at 02:10:25PM +0100, Marc Zyngier wrote: >> Calling irq_find_mapping from outside a irq_{enter,exit} section is >> unsafe and produces ugly messages if CONFIG_PROVE_RCU is enabled: >> If coming from the idle state, the rcu_read_lock call in irq_find_mapping >> will generate an an unpleasant warning. >> >> A solution is to add a new handle_domain_irq entry point into >> the arm code that the interrupt controller code can call. >> This new function takes an irq_domain, and calls into irq_find_domain >> inside the irq_{enter,exit} block. >> >> Interrupt controllers can then be updated to use the new mechanism. > > I merged this last night, and this says it all... > > Subject: rmk build: 244 warnings 49 failures (rmk/v3.16-rc3-70-gc1ed1df) > > arch/arm/kernel/irq.c:81:3: error: implicit declaration of function 'irq_find_mapping' [-Werror=implicit-function-declaration] > > So I'm dropping it. Ouch. Sorry about that. Seems like I only tested this with a config that has CONFIG_IRQ_DOMAIN set. I'll respin in after the merge window. Thanks, M.
diff --git a/arch/arm/include/asm/irq.h b/arch/arm/include/asm/irq.h index 53c15de..8578811 100644 --- a/arch/arm/include/asm/irq.h +++ b/arch/arm/include/asm/irq.h @@ -24,10 +24,12 @@ #ifndef __ASSEMBLY__ struct irqaction; struct pt_regs; +struct irq_domain; extern void migrate_irqs(void); extern void asm_do_IRQ(unsigned int, struct pt_regs *); void handle_IRQ(unsigned int, struct pt_regs *); +void handle_domain_irq(struct irq_domain *, unsigned int, struct pt_regs *); void init_IRQ(void); #ifdef CONFIG_MULTI_IRQ_HANDLER diff --git a/arch/arm/kernel/irq.c b/arch/arm/kernel/irq.c index 2c42576..d6af69f5 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -62,20 +62,30 @@ int arch_show_interrupts(struct seq_file *p, int prec) * not come via this function. Instead, they should provide their * own 'handler'. Used by platform code implementing C-based 1st * level decoding. + * + * handle_domain_irq does the same thing, but also converts the HW + * interrupt number into a logical one using the provided domain. A + * NULL domain indicates that this conversion has already been done. */ -void handle_IRQ(unsigned int irq, struct pt_regs *regs) +void handle_domain_irq(struct irq_domain *domain, + unsigned int hwirq, struct pt_regs *regs) { struct pt_regs *old_regs = set_irq_regs(regs); + unsigned int irq; irq_enter(); + if (domain) + irq = irq_find_mapping(domain, hwirq); + else + irq = hwirq; + /* * Some hardware gives randomly wrong interrupts. Rather * than crashing, do something sensible. */ - if (unlikely(irq >= nr_irqs)) { - if (printk_ratelimit()) - printk(KERN_WARNING "Bad IRQ%u\n", irq); + if (unlikely(!irq || irq >= nr_irqs)) { + pr_warn_ratelimited("Bad IRQ%u (%u)\n", irq, hwirq); ack_bad_irq(irq); } else { generic_handle_irq(irq); @@ -85,6 +95,11 @@ void handle_IRQ(unsigned int irq, struct pt_regs *regs) set_irq_regs(old_regs); } +void handle_IRQ(unsigned int irq, struct pt_regs *regs) +{ + handle_domain_irq(NULL, irq, regs); +} + /* * asm_do_IRQ is the interface to be used from assembly code. */
Calling irq_find_mapping from outside a irq_{enter,exit} section is unsafe and produces ugly messages if CONFIG_PROVE_RCU is enabled: If coming from the idle state, the rcu_read_lock call in irq_find_mapping will generate an an unpleasant warning. A solution is to add a new handle_domain_irq entry point into the arm code that the interrupt controller code can call. This new function takes an irq_domain, and calls into irq_find_domain inside the irq_{enter,exit} block. Interrupt controllers can then be updated to use the new mechanism. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> --- arch/arm/include/asm/irq.h | 2 ++ arch/arm/kernel/irq.c | 23 +++++++++++++++++++---- 2 files changed, 21 insertions(+), 4 deletions(-)