1 /* 2 * PCI IRQ handling code 3 * 4 * Copyright (c) 2008 James Bottomley <James.Bottomley@HansenPartnership.com> 5 * Copyright (C) 2017 Christoph Hellwig. 6 */ 7 8 #include <linux/acpi.h> 9 #include <linux/device.h> 10 #include <linux/kernel.h> 11 #include <linux/export.h> 12 #include <linux/pci.h> 13 14 static void pci_note_irq_problem(struct pci_dev *pdev, const char *reason) 15 { 16 struct pci_dev *parent = to_pci_dev(pdev->dev.parent); 17 18 dev_err(&pdev->dev, 19 "Potentially misrouted IRQ (Bridge %s %04x:%04x)\n", 20 dev_name(&parent->dev), parent->vendor, parent->device); 21 dev_err(&pdev->dev, "%s\n", reason); 22 dev_err(&pdev->dev, "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 */ 38 enum 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 } 62 EXPORT_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 */ 83 int 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 } 100 EXPORT_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 */ 116 void 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 } 120 EXPORT_SYMBOL(pci_free_irq); 121