PCI/irq: Add pci_request_irq() and pci_free_irq() helpers

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@lst.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/include/linux/pci.h b/include/linux/pci.h
index eb3da1a..b23f81b 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);