diff options
Diffstat (limited to 'drivers/pci/irq.c')
| -rw-r--r-- | drivers/pci/irq.c | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/drivers/pci/irq.c b/drivers/pci/irq.c new file mode 100644 index 000000000..a1de501a2 --- /dev/null +++ b/drivers/pci/irq.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PCI IRQ handling code + * + * Copyright (c) 2008 James Bottomley <James.Bottomley@HansenPartnership.com> + * Copyright (C) 2017 Christoph Hellwig. + */ + +#include <linux/acpi.h> +#include <linux/device.h> +#include <linux/kernel.h> +#include <linux/export.h> +#include <linux/pci.h> + +static void pci_note_irq_problem(struct pci_dev *pdev, const char *reason) +{ + struct pci_dev *parent = to_pci_dev(pdev->dev.parent); + + pci_err(pdev, "Potentially misrouted IRQ (Bridge %s %04x:%04x)\n", + dev_name(&parent->dev), parent->vendor, parent->device); + pci_err(pdev, "%s\n", reason); + pci_err(pdev, "Please report to linux-kernel@vger.kernel.org\n"); + WARN_ON(1); +} + +/** + * pci_lost_interrupt - reports a lost PCI interrupt + * @pdev: device whose interrupt is lost + * + * The primary function of this routine is to report a lost interrupt + * in a standard way which users can recognise (instead of blaming the + * driver). + * + * Returns: + * a suggestion for fixing it (although the driver is not required to + * act on this). + */ +enum pci_lost_interrupt_reason pci_lost_interrupt(struct pci_dev *pdev) +{ + if (pdev->msi_enabled || pdev->msix_enabled) { + enum pci_lost_interrupt_reason ret; + + if (pdev->msix_enabled) { + pci_note_irq_problem(pdev, "MSIX routing failure"); + ret = PCI_LOST_IRQ_DISABLE_MSIX; + } else { + pci_note_irq_problem(pdev, "MSI routing failure"); + ret = PCI_LOST_IRQ_DISABLE_MSI; + } + return ret; + } +#ifdef CONFIG_ACPI + if (!(acpi_disabled || acpi_noirq)) { + pci_note_irq_problem(pdev, "Potential ACPI misrouting please reboot with acpi=noirq"); + /* currently no way to fix acpi on the fly */ + return PCI_LOST_IRQ_DISABLE_ACPI; + } +#endif + pci_note_irq_problem(pdev, "unknown cause (not MSI or ACPI)"); + return PCI_LOST_IRQ_NO_INFORMATION; +} +EXPORT_SYMBOL(pci_lost_interrupt); + +/** + * pci_request_irq - allocate an interrupt line for a PCI device + * @dev: PCI device to operate on + * @nr: device-relative interrupt vector index (0-based). + * @handler: Function to be called when the IRQ occurs. + * Primary handler for threaded interrupts. + * If NULL and thread_fn != NULL the default primary handler is + * installed. + * @thread_fn: Function called from the IRQ handler thread + * If NULL, no IRQ thread is created + * @dev_id: Cookie passed back to the handler function + * @fmt: Printf-like format string naming the handler + * + * This call allocates interrupt resources and enables the interrupt line and + * IRQ handling. From the point this call is made @handler and @thread_fn may + * be invoked. All interrupts requested using this function might be shared. + * + * @dev_id must not be NULL and must be globally unique. + */ +int pci_request_irq(struct pci_dev *dev, unsigned int nr, irq_handler_t handler, + irq_handler_t thread_fn, void *dev_id, const char *fmt, ...) +{ + va_list ap; + int ret; + char *devname; + unsigned long irqflags = IRQF_SHARED; + + if (!handler) + irqflags |= IRQF_ONESHOT; + + va_start(ap, fmt); + devname = kvasprintf(GFP_KERNEL, fmt, ap); + va_end(ap); + + ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn, + irqflags, devname, dev_id); + if (ret) + kfree(devname); + return ret; +} +EXPORT_SYMBOL(pci_request_irq); + +/** + * pci_free_irq - free an interrupt allocated with pci_request_irq + * @dev: PCI device to operate on + * @nr: device-relative interrupt vector index (0-based). + * @dev_id: Device identity to free + * + * Remove an interrupt handler. The handler is removed and if the interrupt + * line is no longer in use by any driver it is disabled. The caller must + * ensure the interrupt is disabled on the device before calling this function. + * The function does not return until any executing interrupts for this IRQ + * have completed. + * + * This function must not be called from interrupt context. + */ +void pci_free_irq(struct pci_dev *dev, unsigned int nr, void *dev_id) +{ + kfree(free_irq(pci_irq_vector(dev, nr), dev_id)); +} +EXPORT_SYMBOL(pci_free_irq); |