1/*
 2 * PCI IRQ failure handing code
 3 *
 4 * Copyright (c) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
 
 5 */
 6
 7#include <linux/acpi.h>
 8#include <linux/device.h>
 9#include <linux/kernel.h>
10#include <linux/export.h>
11#include <linux/pci.h>
12
13static void pci_note_irq_problem(struct pci_dev *pdev, const char *reason)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
14{
15	struct pci_dev *parent = to_pci_dev(pdev->dev.parent);
 
 
 
16
17	dev_printk(KERN_ERR, &pdev->dev,
18		   "Potentially misrouted IRQ (Bridge %s %04x:%04x)\n",
19		   dev_name(&parent->dev), parent->vendor, parent->device);
20	dev_printk(KERN_ERR, &pdev->dev, "%s\n", reason);
21	dev_printk(KERN_ERR, &pdev->dev, "Please report to linux-kernel@vger.kernel.org\n");
22	WARN_ON(1);
 
 
 
 
 
 
 
 
23}
 
24
25/**
26 * pci_lost_interrupt - reports a lost PCI interrupt
27 * @pdev:	device whose interrupt is lost
28 * 
29 * The primary function of this routine is to report a lost interrupt
30 * in a standard way which users can recognise (instead of blaming the
31 * driver).
32 *
33 * Returns:
34 *  a suggestion for fixing it (although the driver is not required to
35 * act on this).
 
 
 
 
36 */
37enum pci_lost_interrupt_reason pci_lost_interrupt(struct pci_dev *pdev)
38{
39	if (pdev->msi_enabled || pdev->msix_enabled) {
40		enum pci_lost_interrupt_reason ret;
41
42		if (pdev->msix_enabled) {
43			pci_note_irq_problem(pdev, "MSIX routing failure");
44			ret = PCI_LOST_IRQ_DISABLE_MSIX;
45		} else {
46			pci_note_irq_problem(pdev, "MSI routing failure");
47			ret = PCI_LOST_IRQ_DISABLE_MSI;
48		}
49		return ret;
50	}
51#ifdef CONFIG_ACPI
52	if (!(acpi_disabled || acpi_noirq)) {
53		pci_note_irq_problem(pdev, "Potential ACPI misrouting please reboot with acpi=noirq");
54		/* currently no way to fix acpi on the fly */
55		return PCI_LOST_IRQ_DISABLE_ACPI;
56	}
57#endif
58	pci_note_irq_problem(pdev, "unknown cause (not MSI or ACPI)");
59	return PCI_LOST_IRQ_NO_INFORMATION;
60}
61EXPORT_SYMBOL(pci_lost_interrupt);

 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);