summaryrefslogtreecommitdiffstats
path: root/drivers/pci
diff options
context:
space:
mode:
authorChristoph Hellwig <hch@lst.de>2017-04-13 09:06:42 +0200
committerBjorn Helgaas <bhelgaas@google.com>2017-04-18 13:40:31 -0500
commit704e8953d3e9db29d5d93c0bf6973d86fe15e679 (patch)
treef34833d4b925ce03294c4cae398877f1f1d95f07 /drivers/pci
parent25ce4be72411867e0471908ee9319599035cc624 (diff)
downloadlinux-stable-704e8953d3e9db29d5d93c0bf6973d86fe15e679.tar.gz
linux-stable-704e8953d3e9db29d5d93c0bf6973d86fe15e679.tar.bz2
linux-stable-704e8953d3e9db29d5d93c0bf6973d86fe15e679.zip
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>
Diffstat (limited to 'drivers/pci')
-rw-r--r--drivers/pci/irq.c61
1 files changed, 60 insertions, 1 deletions
diff --git a/drivers/pci/irq.c b/drivers/pci/irq.c
index 6684f153ab57..f1e46d255c5f 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);