On Thu, Apr 13, 2017 at 09:06:42AM +0200, Christoph Hellwig wrote:
> These are small wrappers around request_threaded_irq and free_irq,
> which dynamically allocate space for the device name so that drivers
> don't need to keep static buffers for these around. Additionally it
> works with device-relative vector numbers to make the usage easier,
> and force the IRQF_SHARED flag on given that it has no runtime overhead
> and should be supported by all PCI devices.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Acked-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Let me know if you'd like me to take this series (given an appropriate
ack for the genirq parts).
> ---
> drivers/pci/irq.c | 61 ++++++++++++++++++++++++++++++++++++++++++++++++++++-
> include/linux/pci.h | 6 ++++++
> 2 files changed, 66 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/irq.c b/drivers/pci/irq.c
> index 6684f153ab57..53e7f30d9461 100644
> --- a/drivers/pci/irq.c
> +++ b/drivers/pci/irq.c
> @@ -1,7 +1,8 @@
> /*
> - * PCI IRQ failure handing code
> + * PCI IRQ handing code
> *
> * Copyright (c) 2008 James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
> + * Copyright (C) 2017 Christoph Hellwig.
> */
>
> #include <linux/acpi.h>
> @@ -59,3 +60,61 @@ enum pci_lost_interrupt_reason pci_lost_interrupt(struct pci_dev *pdev)
> 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 interrupt requsted using this function might be shared.
> + *
> + * @dev_id must not ne NULL and 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;
> +
> + 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,
> + IRQF_SHARED, 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);
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index eb3da1a04e6c..b23f81b583ab 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -28,6 +28,7 @@
> #include <linux/kobject.h>
> #include <linux/atomic.h>
> #include <linux/device.h>
> +#include <linux/interrupt.h>
> #include <linux/io.h>
> #include <linux/resource_ext.h>
> #include <uapi/linux/pci.h>
> @@ -1072,6 +1073,11 @@ int pci_select_bars(struct pci_dev *dev, unsigned long flags);
> bool pci_device_is_present(struct pci_dev *pdev);
> void pci_ignore_hotplug(struct pci_dev *dev);
>
> +int __printf(6, 7) 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, ...);
> +void pci_free_irq(struct pci_dev *dev, unsigned int nr, void *dev_id);
> +
> /* ROM control related routines */
> int pci_enable_rom(struct pci_dev *pdev);
> void pci_disable_rom(struct pci_dev *pdev);
> --
> 2.11.0
>
