1 files changed, 60 insertions, 1 deletions

diff --git a/drivers/pci/irq.c b/drivers/pci/irq.c
index f9f2a0324ecc..83d30953ce19 100644
--- a/drivers/pci/irq.c
+++ b/drivers/pci/irq.c
@@ -1,7 +1,8 @@
 /*
- * PCI IRQ failure handing code
+ * PCI IRQ handling code
  *
  * Copyright (c) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
+ * 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 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;
+
+        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);