From 771ee3b04eaac6184312825eb600b4c598f027a5 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Fri, 16 Feb 2007 01:27:25 -0800 Subject: [PATCH] [PATCH] Add a function to handle interrupt affinity setting Provide funtions to: - check, whether an interrupt can set the affinity - pin the interrupt to a given cpu Necessary for the ability to setup clocksources more flexible (e.g. use the different HPET channels per CPU) [akpm@osdl.org: alpha build fix] Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar Cc: john stultz Cc: Roman Zippel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/irq.h | 10 ++++++++++ kernel/irq/manage.c | 40 ++++++++++++++++++++++++++++++++++++++++ kernel/irq/proc.c | 22 +--------------------- 3 files changed, 51 insertions(+), 21 deletions(-) diff --git a/include/linux/irq.h b/include/linux/irq.h index 8930fb0ac9c7..29f715e71bdd 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -238,11 +238,21 @@ static inline void set_pending_irq(unsigned int irq, cpumask_t mask) #endif /* CONFIG_GENERIC_PENDING_IRQ */ +extern int irq_set_affinity(unsigned int irq, cpumask_t cpumask); +extern int irq_can_set_affinity(unsigned int irq); + #else /* CONFIG_SMP */ #define move_native_irq(x) #define move_masked_irq(x) +static inline int irq_set_affinity(unsigned int irq, cpumask_t cpumask) +{ + return -EINVAL; +} + +static inline int irq_can_set_affinity(unsigned int irq) { return 0; } + #endif /* CONFIG_SMP */ #ifdef CONFIG_IRQBALANCE diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index cd790ad0ae57..5597c157442a 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -38,6 +38,46 @@ void synchronize_irq(unsigned int irq) } EXPORT_SYMBOL(synchronize_irq); +/** + * irq_can_set_affinity - Check if the affinity of a given irq can be set + * @irq: Interrupt to check + * + */ +int irq_can_set_affinity(unsigned int irq) +{ + struct irq_desc *desc = irq_desc + irq; + + if (CHECK_IRQ_PER_CPU(desc->status) || !desc->chip || + !desc->chip->set_affinity) + return 0; + + return 1; +} + +/** + * irq_set_affinity - Set the irq affinity of a given irq + * @irq: Interrupt to set affinity + * @cpumask: cpumask + * + */ +int irq_set_affinity(unsigned int irq, cpumask_t cpumask) +{ + struct irq_desc *desc = irq_desc + irq; + + if (!desc->chip->set_affinity) + return -EINVAL; + + set_balance_irq_affinity(irq, cpumask); + +#ifdef CONFIG_GENERIC_PENDING_IRQ + set_pending_irq(irq, cpumask); +#else + desc->affinity = cpumask; + desc->chip->set_affinity(irq, cpumask); +#endif + return 0; +} + #endif /** diff --git a/kernel/irq/proc.c b/kernel/irq/proc.c index bb44bc995d6e..2db91eb54ad8 100644 --- a/kernel/irq/proc.c +++ b/kernel/irq/proc.c @@ -16,26 +16,6 @@ static struct proc_dir_entry *root_irq_dir; #ifdef CONFIG_SMP -#ifdef CONFIG_GENERIC_PENDING_IRQ -void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val) -{ - set_balance_irq_affinity(irq, mask_val); - - /* - * Save these away for later use. Re-progam when the - * interrupt is pending - */ - set_pending_irq(irq, mask_val); -} -#else -void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val) -{ - set_balance_irq_affinity(irq, mask_val); - irq_desc[irq].affinity = mask_val; - irq_desc[irq].chip->set_affinity(irq, mask_val); -} -#endif - static int irq_affinity_read_proc(char *page, char **start, off_t off, int count, int *eof, void *data) { @@ -73,7 +53,7 @@ static int irq_affinity_write_proc(struct file *file, const char __user *buffer, code to set default SMP affinity. */ return select_smp_affinity(irq) ? -EINVAL : full_count; - proc_set_irq_affinity(irq, new_value); + irq_set_affinity(irq, new_value); return full_count; }