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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
388c8c16 | 2 | /* |
704e8953 | 3 | * PCI IRQ handling code |
388c8c16 JB |
4 | * |
5 | * Copyright (c) 2008 James Bottomley <James.Bottomley@HansenPartnership.com> | |
704e8953 | 6 | * Copyright (C) 2017 Christoph Hellwig. |
388c8c16 JB |
7 | */ |
8 | ||
388c8c16 JB |
9 | #include <linux/device.h> |
10 | #include <linux/kernel.h> | |
363c75db | 11 | #include <linux/export.h> |
388c8c16 JB |
12 | #include <linux/pci.h> |
13 | ||
704e8953 CH |
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 | */ | |
33 | int 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; | |
f7368a55 HK |
39 | unsigned long irqflags = IRQF_SHARED; |
40 | ||
41 | if (!handler) | |
42 | irqflags |= IRQF_ONESHOT; | |
704e8953 CH |
43 | |
44 | va_start(ap, fmt); | |
45 | devname = kvasprintf(GFP_KERNEL, fmt, ap); | |
46 | va_end(ap); | |
2d9cd957 ZH |
47 | if (!devname) |
48 | return -ENOMEM; | |
704e8953 CH |
49 | |
50 | ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn, | |
f7368a55 | 51 | irqflags, devname, dev_id); |
704e8953 CH |
52 | if (ret) |
53 | kfree(devname); | |
54 | return ret; | |
55 | } | |
56 | EXPORT_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 | */ | |
72 | void 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 | } | |
76 | EXPORT_SYMBOL(pci_free_irq); |