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_err(&pdev->dev,
18		"Potentially misrouted IRQ (Bridge %s %04x:%04x)\n",
19		dev_name(&parent->dev), parent->vendor, parent->device);
20	dev_err(&pdev->dev, "%s\n", reason);
21	dev_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);
62