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// SPDX-License-Identifier: GPL-2.0
/*
* PCI IRQ handling code
*
* Copyright (c) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
* Copyright (C) 2017 Christoph Hellwig.
*/
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/pci.h>
/**
* 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;
unsigned long irqflags = IRQF_SHARED;
if (!handler)
irqflags |= IRQF_ONESHOT;
va_start(ap, fmt);
devname = kvasprintf(GFP_KERNEL, fmt, ap);
va_end(ap);
if (!devname)
return -ENOMEM;
ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn,
irqflags, 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);
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