cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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irq.c (2424B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * PCI IRQ handling code
      4 *
      5 * Copyright (c) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
      6 * Copyright (C) 2017 Christoph Hellwig.
      7 */
      8
      9#include <linux/device.h>
     10#include <linux/kernel.h>
     11#include <linux/export.h>
     12#include <linux/pci.h>
     13
     14/**
     15 * pci_request_irq - allocate an interrupt line for a PCI device
     16 * @dev:	PCI device to operate on
     17 * @nr:		device-relative interrupt vector index (0-based).
     18 * @handler:	Function to be called when the IRQ occurs.
     19 *		Primary handler for threaded interrupts.
     20 *		If NULL and thread_fn != NULL the default primary handler is
     21 *		installed.
     22 * @thread_fn:	Function called from the IRQ handler thread
     23 *		If NULL, no IRQ thread is created
     24 * @dev_id:	Cookie passed back to the handler function
     25 * @fmt:	Printf-like format string naming the handler
     26 *
     27 * This call allocates interrupt resources and enables the interrupt line and
     28 * IRQ handling. From the point this call is made @handler and @thread_fn may
     29 * be invoked.  All interrupts requested using this function might be shared.
     30 *
     31 * @dev_id must not be NULL and must be globally unique.
     32 */
     33int pci_request_irq(struct pci_dev *dev, unsigned int nr, irq_handler_t handler,
     34		irq_handler_t thread_fn, void *dev_id, const char *fmt, ...)
     35{
     36	va_list ap;
     37	int ret;
     38	char *devname;
     39	unsigned long irqflags = IRQF_SHARED;
     40
     41	if (!handler)
     42		irqflags |= IRQF_ONESHOT;
     43
     44	va_start(ap, fmt);
     45	devname = kvasprintf(GFP_KERNEL, fmt, ap);
     46	va_end(ap);
     47
     48	ret = request_threaded_irq(pci_irq_vector(dev, nr), handler, thread_fn,
     49				   irqflags, devname, dev_id);
     50	if (ret)
     51		kfree(devname);
     52	return ret;
     53}
     54EXPORT_SYMBOL(pci_request_irq);
     55
     56/**
     57 * pci_free_irq - free an interrupt allocated with pci_request_irq
     58 * @dev:	PCI device to operate on
     59 * @nr:		device-relative interrupt vector index (0-based).
     60 * @dev_id:	Device identity to free
     61 *
     62 * Remove an interrupt handler. The handler is removed and if the interrupt
     63 * line is no longer in use by any driver it is disabled.  The caller must
     64 * ensure the interrupt is disabled on the device before calling this function.
     65 * The function does not return until any executing interrupts for this IRQ
     66 * have completed.
     67 *
     68 * This function must not be called from interrupt context.
     69 */
     70void pci_free_irq(struct pci_dev *dev, unsigned int nr, void *dev_id)
     71{
     72	kfree(free_irq(pci_irq_vector(dev, nr), dev_id));
     73}
     74EXPORT_SYMBOL(pci_free_irq);