From d3dcb436f61593843af178d4a520c8c43c04d3fc Mon Sep 17 00:00:00 2001 From: Grant Likely Date: Mon, 10 Jun 2013 12:19:17 +0100 Subject: [PATCH] irqdomain: make irq_linear_revmap() a fast path again Over the years, irq_linear_revmap() gained tests and checks to make sure callers were using it safely, which while important, also make it less of a fast path. After the irqdomain refactoring done recently, it is now possible to make irq_linear_revmap() a fast path again. This patch moves irq_linear_revmap() to the header file and makes it a static inline so that interrupt controller drivers using a linear mapping can decode the virq from a hwirq in just a couple of instructions. Signed-off-by: Grant Likely --- include/linux/irqdomain.h | 19 ++++++++++++++++--- kernel/irq/irqdomain.c | 34 ++++++++-------------------------- 2 files changed, 24 insertions(+), 29 deletions(-) diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h index 6efbeccac56c..c983ed18c332 100644 --- a/include/linux/irqdomain.h +++ b/include/linux/irqdomain.h @@ -176,6 +176,22 @@ extern void irq_domain_associate_many(struct irq_domain *domain, extern unsigned int irq_create_mapping(struct irq_domain *host, irq_hw_number_t hwirq); extern void irq_dispose_mapping(unsigned int virq); + +/** + * irq_linear_revmap() - Find a linux irq from a hw irq number. + * @domain: domain owning this hardware interrupt + * @hwirq: hardware irq number in that domain space + * + * This is a fast path alternative to irq_find_mapping() that can be + * called directly by irq controller code to save a handful of + * instructions. It is always safe to call, but won't find irqs mapped + * using the radix tree. + */ +static inline unsigned int irq_linear_revmap(struct irq_domain *domain, + irq_hw_number_t hwirq) +{ + return hwirq < domain->revmap_size ? domain->linear_revmap[hwirq] : 0; +} extern unsigned int irq_find_mapping(struct irq_domain *host, irq_hw_number_t hwirq); extern unsigned int irq_create_direct_mapping(struct irq_domain *host); @@ -189,9 +205,6 @@ static inline int irq_create_identity_mapping(struct irq_domain *host, return irq_create_strict_mappings(host, hwirq, hwirq, 1); } -extern unsigned int irq_linear_revmap(struct irq_domain *host, - irq_hw_number_t hwirq); - extern const struct irq_domain_ops irq_domain_simple_ops; /* stock xlate functions */ diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c index e47b35671384..836a0f7ec2a9 100644 --- a/kernel/irq/irqdomain.c +++ b/kernel/irq/irqdomain.c @@ -559,35 +559,17 @@ unsigned int irq_find_mapping(struct irq_domain *domain, return hwirq; } - return irq_linear_revmap(domain, hwirq); + /* Check if the hwirq is in the linear revmap. */ + if (hwirq < domain->revmap_size) + return domain->linear_revmap[hwirq]; + + rcu_read_lock(); + data = radix_tree_lookup(&domain->revmap_tree, hwirq); + rcu_read_unlock(); + return data ? data->irq : 0; } EXPORT_SYMBOL_GPL(irq_find_mapping); -/** - * irq_linear_revmap() - Find a linux irq from a hw irq number. - * @domain: domain owning this hardware interrupt - * @hwirq: hardware irq number in that domain space - * - * This is a fast path that can be called directly by irq controller code to - * save a handful of instructions. - */ -unsigned int irq_linear_revmap(struct irq_domain *domain, - irq_hw_number_t hwirq) -{ - struct irq_data *data; - - /* Check revmap bounds; complain if exceeded */ - if (hwirq >= domain->revmap_size) { - rcu_read_lock(); - data = radix_tree_lookup(&domain->revmap_tree, hwirq); - rcu_read_unlock(); - return data ? data->irq : 0; - } - - return domain->linear_revmap[hwirq]; -} -EXPORT_SYMBOL_GPL(irq_linear_revmap); - #ifdef CONFIG_IRQ_DOMAIN_DEBUG static int virq_debug_show(struct seq_file *m, void *private) { -- 2.39.5