[PATCHv7 04/13] irqdomain: add irq_alloc_mapping() function
From: Thomas Petazzoni <hidden>
Date: 2013-08-07 09:32:25
Also in:
linux-pci
Subsystem:
irq domains (irq number mapping library), irq subsystem, the rest · Maintainers:
Thomas Gleixner, Linus Torvalds
This commit extends the irqdomain subsystem with an irq_alloc_mapping() function which allows to let the irqdomain code find an available hwirq number in the range [ 0 ; domain size ] for the given domain, and create a virq mapping for it. Signed-off-by: Thomas Petazzoni <redacted> Acked-by: Grant Likely <redacted> Tested-by: Daniel Price <redacted> --- include/linux/irqdomain.h | 2 ++ kernel/irq/irqdomain.c | 36 ++++++++++++++++++++++++++++++++++++ 2 files changed, 38 insertions(+)
diff --git a/include/linux/irqdomain.h b/include/linux/irqdomain.h
index c983ed1..1ffa336 100644
--- a/include/linux/irqdomain.h
+++ b/include/linux/irqdomain.h@@ -195,6 +195,8 @@ static inline unsigned int irq_linear_revmap(struct irq_domain *domain, 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); +extern unsigned int irq_alloc_mapping(struct irq_domain *host, + irq_hw_number_t *hwirq); extern int irq_create_strict_mappings(struct irq_domain *domain, unsigned int irq_base, irq_hw_number_t hwirq_base, int count);
diff --git a/kernel/irq/irqdomain.c b/kernel/irq/irqdomain.c
index 706724e..034bbac 100644
--- a/kernel/irq/irqdomain.c
+++ b/kernel/irq/irqdomain.c@@ -375,6 +375,42 @@ unsigned int irq_create_direct_mapping(struct irq_domain *domain) EXPORT_SYMBOL_GPL(irq_create_direct_mapping); /** + * irq_alloc_mapping() - Allocate an irq for mapping + * @domain: domain to allocate the irq for or NULL for default domain + * @hwirq: reference to the returned hwirq + * + * This routine are used for irq controllers which can choose the + * hardware interrupt number from a range [ 0 ; domain size ], such as + * is often the case with PCI MSI controllers. The function will + * returned the allocated hwirq number in the hwirq pointer, and the + * corresponding virq number as the return value. + */ +unsigned int irq_alloc_mapping(struct irq_domain *domain, + irq_hw_number_t *out_hwirq) +{ + irq_hw_number_t hwirq; + int rc; + + pr_debug("irq_alloc_mapping(0x%p)\n", domain); + + for (hwirq = 0; hwirq < domain->revmap_size; hwirq++) + if (domain->linear_revmap[hwirq] == 0) + break; + + if (hwirq == domain->hwirq_max) { + pr_debug("-> no available hwirq found\n"); + return 0; + } + + rc = irq_create_mapping(domain, hwirq); + if (rc) + *out_hwirq = hwirq; + + return rc; +} +EXPORT_SYMBOL_GPL(irq_alloc_mapping); + +/** * irq_create_mapping() - Map a hardware interrupt into linux irq space * @domain: domain owning this hardware interrupt or NULL for default domain * @hwirq: hardware irq number in that domain space
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1.8.1.2