Messages in this thread Patch in this message | | | From | Marc Zyngier <> | Subject | [PATCH v2 02/15] ARM: pass IRQ domain to the core IRQ handler | Date | Tue, 8 Jul 2014 14:45:40 +0100 |
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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> --- Sending the right patch this time, with the missing includes that would otherwise break the build...
arch/arm/include/asm/irq.h | 2 ++ arch/arm/kernel/irq.c | 25 +++++++++++++++++++++---- 2 files changed, 23 insertions(+), 4 deletions(-)
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..a9e37434 100644 --- a/arch/arm/kernel/irq.c +++ b/arch/arm/kernel/irq.c @@ -27,7 +27,9 @@ #include <linux/interrupt.h> #include <linux/irq.h> #include <linux/irqchip.h> +#include <linux/irqdomain.h> #include <linux/random.h> +#include <linux/ratelimit.h> #include <linux/smp.h> #include <linux/init.h> #include <linux/seq_file.h> @@ -62,20 +64,30 @@ 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 +97,11 @@ 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. */ -- 2.0.0
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