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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 | ||
9 | #include <linux/acpi.h> | |
10 | #include <linux/device.h> | |
11 | #include <linux/kernel.h> | |
363c75db | 12 | #include <linux/export.h> |
388c8c16 JB |
13 | #include <linux/pci.h> |
14 | ||
15 | static 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 | ||
438be3c6 JP |
19 | dev_err(&pdev->dev, |
20 | "Potentially misrouted IRQ (Bridge %s %04x:%04x)\n", | |
21 | dev_name(&parent->dev), parent->vendor, parent->device); | |
22 | dev_err(&pdev->dev, "%s\n", reason); | |
23 | dev_err(&pdev->dev, "Please report to linux-kernel@vger.kernel.org\n"); | |
388c8c16 JB |
24 | WARN_ON(1); |
25 | } | |
26 | ||
27 | /** | |
28 | * pci_lost_interrupt - reports a lost PCI interrupt | |
29 | * @pdev: device whose interrupt is lost | |
f7625980 | 30 | * |
388c8c16 JB |
31 | * The primary function of this routine is to report a lost interrupt |
32 | * in a standard way which users can recognise (instead of blaming the | |
33 | * driver). | |
34 | * | |
35 | * Returns: | |
0e056eb5 | 36 | * a suggestion for fixing it (although the driver is not required to |
388c8c16 JB |
37 | * act on this). |
38 | */ | |
39 | enum pci_lost_interrupt_reason pci_lost_interrupt(struct pci_dev *pdev) | |
40 | { | |
41 | if (pdev->msi_enabled || pdev->msix_enabled) { | |
42 | enum pci_lost_interrupt_reason ret; | |
43 | ||
44 | if (pdev->msix_enabled) { | |
45 | pci_note_irq_problem(pdev, "MSIX routing failure"); | |
46 | ret = PCI_LOST_IRQ_DISABLE_MSIX; | |
47 | } else { | |
48 | pci_note_irq_problem(pdev, "MSI routing failure"); | |
49 | ret = PCI_LOST_IRQ_DISABLE_MSI; | |
50 | } | |
51 | return ret; | |
52 | } | |
53 | #ifdef CONFIG_ACPI | |
54 | if (!(acpi_disabled || acpi_noirq)) { | |
55 | pci_note_irq_problem(pdev, "Potential ACPI misrouting please reboot with acpi=noirq"); | |
56 | /* currently no way to fix acpi on the fly */ | |
57 | return PCI_LOST_IRQ_DISABLE_ACPI; | |
58 | } | |
59 | #endif | |
60 | pci_note_irq_problem(pdev, "unknown cause (not MSI or ACPI)"); | |
61 | return PCI_LOST_IRQ_NO_INFORMATION; | |
62 | } | |
63 | EXPORT_SYMBOL(pci_lost_interrupt); | |
704e8953 CH |
64 | |
65 | /** | |
66 | * pci_request_irq - allocate an interrupt line for a PCI device | |
67 | * @dev: PCI device to operate on | |
68 | * @nr: device-relative interrupt vector index (0-based). | |
69 | * @handler: Function to be called when the IRQ occurs. | |
70 | * Primary handler for threaded interrupts. | |
71 | * If NULL and thread_fn != NULL the default primary handler is | |
72 | * installed. | |
73 | * @thread_fn: Function called from the IRQ handler thread | |
74 | * If NULL, no IRQ thread is created | |
75 | * @dev_id: Cookie passed back to the handler function | |
76 | * @fmt: Printf-like format string naming the handler | |
77 | * | |
78 | * This call allocates interrupt resources and enables the interrupt line and | |
79 | * IRQ handling. From the point this call is made @handler and @thread_fn may | |
80 | * be invoked. All interrupts requested using this function might be shared. | |
81 | * | |
82 | * @dev_id must not be NULL and must be globally unique. | |
83 | */ | |
84 | int pci_request_irq(struct pci_dev *dev, unsigned int nr, irq_handler_t handler, | |
85 | irq_handler_t thread_fn, void *dev_id, const char *fmt, ...) | |
86 | { | |
87 | va_list ap; | |
88 | int ret; | |
89 | char *devname; | |
90 | ||
91 | va_start(ap, fmt); | |
92 | devname = kvasprintf(GFP_KERNEL, fmt, ap); | |
93 | va_end(ap); | |
94 | ||
95 | ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn, | |
96 | IRQF_SHARED, devname, dev_id); | |
97 | if (ret) | |
98 | kfree(devname); | |
99 | return ret; | |
100 | } | |
101 | EXPORT_SYMBOL(pci_request_irq); | |
102 | ||
103 | /** | |
104 | * pci_free_irq - free an interrupt allocated with pci_request_irq | |
105 | * @dev: PCI device to operate on | |
106 | * @nr: device-relative interrupt vector index (0-based). | |
107 | * @dev_id: Device identity to free | |
108 | * | |
109 | * Remove an interrupt handler. The handler is removed and if the interrupt | |
110 | * line is no longer in use by any driver it is disabled. The caller must | |
111 | * ensure the interrupt is disabled on the device before calling this function. | |
112 | * The function does not return until any executing interrupts for this IRQ | |
113 | * have completed. | |
114 | * | |
115 | * This function must not be called from interrupt context. | |
116 | */ | |
117 | void pci_free_irq(struct pci_dev *dev, unsigned int nr, void *dev_id) | |
118 | { | |
119 | kfree(free_irq(pci_irq_vector(dev, nr), dev_id)); | |
120 | } | |
121 | EXPORT_SYMBOL(pci_free_irq); |