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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCI IRQ handling code
4 *
5 * Copyright (c) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
6 * Copyright (C) 2017 Christoph Hellwig.
7 */
8
9#include <linux/device.h>
10#include <linux/kernel.h>
11#include <linux/export.h>
12#include <linux/pci.h>
13
14/**
15 * pci_request_irq - allocate an interrupt line for a PCI device
16 * @dev: PCI device to operate on
17 * @nr: device-relative interrupt vector index (0-based).
18 * @handler: Function to be called when the IRQ occurs.
19 * Primary handler for threaded interrupts.
20 * If NULL and thread_fn != NULL the default primary handler is
21 * installed.
22 * @thread_fn: Function called from the IRQ handler thread
23 * If NULL, no IRQ thread is created
24 * @dev_id: Cookie passed back to the handler function
25 * @fmt: Printf-like format string naming the handler
26 *
27 * This call allocates interrupt resources and enables the interrupt line and
28 * IRQ handling. From the point this call is made @handler and @thread_fn may
29 * be invoked. All interrupts requested using this function might be shared.
30 *
31 * @dev_id must not be NULL and must be globally unique.
32 */
33int pci_request_irq(struct pci_dev *dev, unsigned int nr, irq_handler_t handler,
34 irq_handler_t thread_fn, void *dev_id, const char *fmt, ...)
35{
36 va_list ap;
37 int ret;
38 char *devname;
39 unsigned long irqflags = IRQF_SHARED;
40
41 if (!handler)
42 irqflags |= IRQF_ONESHOT;
43
44 va_start(ap, fmt);
45 devname = kvasprintf(GFP_KERNEL, fmt, ap);
46 va_end(ap);
47 if (!devname)
48 return -ENOMEM;
49
50 ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn,
51 irqflags, devname, dev_id);
52 if (ret)
53 kfree(devname);
54 return ret;
55}
56EXPORT_SYMBOL(pci_request_irq);
57
58/**
59 * pci_free_irq - free an interrupt allocated with pci_request_irq
60 * @dev: PCI device to operate on
61 * @nr: device-relative interrupt vector index (0-based).
62 * @dev_id: Device identity to free
63 *
64 * Remove an interrupt handler. The handler is removed and if the interrupt
65 * line is no longer in use by any driver it is disabled. The caller must
66 * ensure the interrupt is disabled on the device before calling this function.
67 * The function does not return until any executing interrupts for this IRQ
68 * have completed.
69 *
70 * This function must not be called from interrupt context.
71 */
72void pci_free_irq(struct pci_dev *dev, unsigned int nr, void *dev_id)
73{
74 kfree(free_irq(pci_irq_vector(dev, nr), dev_id));
75}
76EXPORT_SYMBOL(pci_free_irq);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCI IRQ handling code
4 *
5 * Copyright (c) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
6 * Copyright (C) 2017 Christoph Hellwig.
7 */
8
9#include <linux/device.h>
10#include <linux/kernel.h>
11#include <linux/export.h>
12#include <linux/pci.h>
13
14/**
15 * pci_request_irq - allocate an interrupt line for a PCI device
16 * @dev: PCI device to operate on
17 * @nr: device-relative interrupt vector index (0-based).
18 * @handler: Function to be called when the IRQ occurs.
19 * Primary handler for threaded interrupts.
20 * If NULL and thread_fn != NULL the default primary handler is
21 * installed.
22 * @thread_fn: Function called from the IRQ handler thread
23 * If NULL, no IRQ thread is created
24 * @dev_id: Cookie passed back to the handler function
25 * @fmt: Printf-like format string naming the handler
26 *
27 * This call allocates interrupt resources and enables the interrupt line and
28 * IRQ handling. From the point this call is made @handler and @thread_fn may
29 * be invoked. All interrupts requested using this function might be shared.
30 *
31 * @dev_id must not be NULL and must be globally unique.
32 */
33int pci_request_irq(struct pci_dev *dev, unsigned int nr, irq_handler_t handler,
34 irq_handler_t thread_fn, void *dev_id, const char *fmt, ...)
35{
36 va_list ap;
37 int ret;
38 char *devname;
39 unsigned long irqflags = IRQF_SHARED;
40
41 if (!handler)
42 irqflags |= IRQF_ONESHOT;
43
44 va_start(ap, fmt);
45 devname = kvasprintf(GFP_KERNEL, fmt, ap);
46 va_end(ap);
47 if (!devname)
48 return -ENOMEM;
49
50 ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn,
51 irqflags, devname, dev_id);
52 if (ret)
53 kfree(devname);
54 return ret;
55}
56EXPORT_SYMBOL(pci_request_irq);
57
58/**
59 * pci_free_irq - free an interrupt allocated with pci_request_irq
60 * @dev: PCI device to operate on
61 * @nr: device-relative interrupt vector index (0-based).
62 * @dev_id: Device identity to free
63 *
64 * Remove an interrupt handler. The handler is removed and if the interrupt
65 * line is no longer in use by any driver it is disabled. The caller must
66 * ensure the interrupt is disabled on the device before calling this function.
67 * The function does not return until any executing interrupts for this IRQ
68 * have completed.
69 *
70 * This function must not be called from interrupt context.
71 */
72void pci_free_irq(struct pci_dev *dev, unsigned int nr, void *dev_id)
73{
74 kfree(free_irq(pci_irq_vector(dev, nr), dev_id));
75}
76EXPORT_SYMBOL(pci_free_irq);