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
48	ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn,
49				   irqflags, devname, dev_id);
50	if (ret)
51		kfree(devname);
52	return ret;
53}
54EXPORT_SYMBOL(pci_request_irq);
55
56/**
57 * pci_free_irq - free an interrupt allocated with pci_request_irq
58 * @dev:	PCI device to operate on
59 * @nr:		device-relative interrupt vector index (0-based).
60 * @dev_id:	Device identity to free
61 *
62 * Remove an interrupt handler. The handler is removed and if the interrupt
63 * line is no longer in use by any driver it is disabled.  The caller must
64 * ensure the interrupt is disabled on the device before calling this function.
65 * The function does not return until any executing interrupts for this IRQ
66 * have completed.
67 *
68 * This function must not be called from interrupt context.
69 */
70void pci_free_irq(struct pci_dev *dev, unsigned int nr, void *dev_id)
71{
72	kfree(free_irq(pci_irq_vector(dev, nr), dev_id));
73}
74EXPORT_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/acpi.h>
 10#include <linux/device.h>
 11#include <linux/kernel.h>
 12#include <linux/export.h>
 13#include <linux/pci.h>
 14
 15static void pci_note_irq_problem(struct pci_dev *pdev, const char *reason)
 16{
 17	struct pci_dev *parent = to_pci_dev(pdev->dev.parent);
 18
 19	pci_err(pdev, "Potentially misrouted IRQ (Bridge %s %04x:%04x)\n",
 20		dev_name(&parent->dev), parent->vendor, parent->device);
 21	pci_err(pdev, "%s\n", reason);
 22	pci_err(pdev, "Please report to linux-kernel@vger.kernel.org\n");
 23	WARN_ON(1);
 24}
 25
 26/**
 27 * pci_lost_interrupt - reports a lost PCI interrupt
 28 * @pdev:	device whose interrupt is lost
 29 *
 30 * The primary function of this routine is to report a lost interrupt
 31 * in a standard way which users can recognise (instead of blaming the
 32 * driver).
 33 *
 34 * Returns:
 35 * a suggestion for fixing it (although the driver is not required to
 36 * act on this).
 37 */
 38enum pci_lost_interrupt_reason pci_lost_interrupt(struct pci_dev *pdev)
 39{
 40	if (pdev->msi_enabled || pdev->msix_enabled) {
 41		enum pci_lost_interrupt_reason ret;
 42
 43		if (pdev->msix_enabled) {
 44			pci_note_irq_problem(pdev, "MSIX routing failure");
 45			ret = PCI_LOST_IRQ_DISABLE_MSIX;
 46		} else {
 47			pci_note_irq_problem(pdev, "MSI routing failure");
 48			ret = PCI_LOST_IRQ_DISABLE_MSI;
 49		}
 50		return ret;
 51	}
 52#ifdef CONFIG_ACPI
 53	if (!(acpi_disabled || acpi_noirq)) {
 54		pci_note_irq_problem(pdev, "Potential ACPI misrouting please reboot with acpi=noirq");
 55		/* currently no way to fix acpi on the fly */
 56		return PCI_LOST_IRQ_DISABLE_ACPI;
 57	}
 58#endif
 59	pci_note_irq_problem(pdev, "unknown cause (not MSI or ACPI)");
 60	return PCI_LOST_IRQ_NO_INFORMATION;
 61}
 62EXPORT_SYMBOL(pci_lost_interrupt);
 63
 64/**
 65 * pci_request_irq - allocate an interrupt line for a PCI device
 66 * @dev:	PCI device to operate on
 67 * @nr:		device-relative interrupt vector index (0-based).
 68 * @handler:	Function to be called when the IRQ occurs.
 69 *		Primary handler for threaded interrupts.
 70 *		If NULL and thread_fn != NULL the default primary handler is
 71 *		installed.
 72 * @thread_fn:	Function called from the IRQ handler thread
 73 *		If NULL, no IRQ thread is created
 74 * @dev_id:	Cookie passed back to the handler function
 75 * @fmt:	Printf-like format string naming the handler
 76 *
 77 * This call allocates interrupt resources and enables the interrupt line and
 78 * IRQ handling. From the point this call is made @handler and @thread_fn may
 79 * be invoked.  All interrupts requested using this function might be shared.
 80 *
 81 * @dev_id must not be NULL and must be globally unique.
 82 */
 83int pci_request_irq(struct pci_dev *dev, unsigned int nr, irq_handler_t handler,
 84		irq_handler_t thread_fn, void *dev_id, const char *fmt, ...)
 85{
 86	va_list ap;
 87	int ret;
 88	char *devname;
 
 
 
 
 89
 90	va_start(ap, fmt);
 91	devname = kvasprintf(GFP_KERNEL, fmt, ap);
 92	va_end(ap);
 93
 94	ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn,
 95			IRQF_SHARED, devname, dev_id);
 96	if (ret)
 97		kfree(devname);
 98	return ret;
 99}
100EXPORT_SYMBOL(pci_request_irq);
101
102/**
103 * pci_free_irq - free an interrupt allocated with pci_request_irq
104 * @dev:	PCI device to operate on
105 * @nr:		device-relative interrupt vector index (0-based).
106 * @dev_id:	Device identity to free
107 *
108 * Remove an interrupt handler. The handler is removed and if the interrupt
109 * line is no longer in use by any driver it is disabled.  The caller must
110 * ensure the interrupt is disabled on the device before calling this function.
111 * The function does not return until any executing interrupts for this IRQ
112 * have completed.
113 *
114 * This function must not be called from interrupt context.
115 */
116void pci_free_irq(struct pci_dev *dev, unsigned int nr, void *dev_id)
117{
118	kfree(free_irq(pci_irq_vector(dev, nr), dev_id));
119}
120EXPORT_SYMBOL(pci_free_irq);