From 704e8953d3e9db29d5d93c0bf6973d86fe15e679 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 13 Apr 2017 09:06:42 +0200 Subject: PCI/irq: Add pci_request_irq() and pci_free_irq() helpers These are small wrappers around request_threaded_irq() and free_irq(), which dynamically allocate space for the device name so that drivers don't need to keep static buffers for these around. Additionally it works with device-relative vector numbers to make the usage easier, and force the IRQF_SHARED flag on given that it has no runtime overhead and should be supported by all PCI devices. Signed-off-by: Christoph Hellwig Signed-off-by: Bjorn Helgaas Reviewed-by: Thomas Gleixner --- drivers/pci/irq.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 60 insertions(+), 1 deletion(-) (limited to 'drivers/pci/irq.c') diff --git a/drivers/pci/irq.c b/drivers/pci/irq.c index 6684f153ab57..f1e46d255c5f 100644 --- a/drivers/pci/irq.c +++ b/drivers/pci/irq.c @@ -1,7 +1,8 @@ /* - * PCI IRQ failure handing code + * PCI IRQ handling code * * Copyright (c) 2008 James Bottomley + * Copyright (C) 2017 Christoph Hellwig. */ #include @@ -59,3 +60,61 @@ enum pci_lost_interrupt_reason pci_lost_interrupt(struct pci_dev *pdev) return PCI_LOST_IRQ_NO_INFORMATION; } EXPORT_SYMBOL(pci_lost_interrupt); + +/** + * pci_request_irq - allocate an interrupt line for a PCI device + * @dev: PCI device to operate on + * @nr: device-relative interrupt vector index (0-based). + * @handler: Function to be called when the IRQ occurs. + * Primary handler for threaded interrupts. + * If NULL and thread_fn != NULL the default primary handler is + * installed. + * @thread_fn: Function called from the IRQ handler thread + * If NULL, no IRQ thread is created + * @dev_id: Cookie passed back to the handler function + * @fmt: Printf-like format string naming the handler + * + * This call allocates interrupt resources and enables the interrupt line and + * IRQ handling. From the point this call is made @handler and @thread_fn may + * be invoked. All interrupts requested using this function might be shared. + * + * @dev_id must not be NULL and must be globally unique. + */ +int pci_request_irq(struct pci_dev *dev, unsigned int nr, irq_handler_t handler, + irq_handler_t thread_fn, void *dev_id, const char *fmt, ...) +{ + va_list ap; + int ret; + char *devname; + + va_start(ap, fmt); + devname = kvasprintf(GFP_KERNEL, fmt, ap); + va_end(ap); + + ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn, + IRQF_SHARED, devname, dev_id); + if (ret) + kfree(devname); + return ret; +} +EXPORT_SYMBOL(pci_request_irq); + +/** + * pci_free_irq - free an interrupt allocated with pci_request_irq + * @dev: PCI device to operate on + * @nr: device-relative interrupt vector index (0-based). + * @dev_id: Device identity to free + * + * Remove an interrupt handler. The handler is removed and if the interrupt + * line is no longer in use by any driver it is disabled. The caller must + * ensure the interrupt is disabled on the device before calling this function. + * The function does not return until any executing interrupts for this IRQ + * have completed. + * + * This function must not be called from interrupt context. + */ +void pci_free_irq(struct pci_dev *dev, unsigned int nr, void *dev_id) +{ + kfree(free_irq(pci_irq_vector(dev, nr), dev_id)); +} +EXPORT_SYMBOL(pci_free_irq); -- cgit