path: root/drivers/pci/msi.c

/*
 * File:	msi.c
 * Purpose:	PCI Message Signaled Interrupt (MSI)
 *
 * Copyright (C) 2003-2004 Intel
 * Copyright (C) Tom Long Nguyen (tom.l.nguyen@intel.com)
 */

#include <linux/err.h>
#include <linux/mm.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/export.h>
#include <linux/ioport.h>
#include <linux/pci.h>
#include <linux/proc_fs.h>
#include <linux/msi.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/io.h>
#include <linux/slab.h>

#include "pci.h"

static int pci_msi_enable = 1;

#define msix_table_size(flags)	((flags & PCI_MSIX_FLAGS_QSIZE) + 1)


/* Arch hooks */

int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
{
	struct msi_chip *chip = dev->bus->msi;
	int err;

	if (!chip || !chip->setup_irq)
		return -EINVAL;

	err = chip->setup_irq(chip, dev, desc);
	if (err < 0)
		return err;

	irq_set_chip_data(desc->irq, chip);

	return 0;
}

void __weak arch_teardown_msi_irq(unsigned int irq)
{
	struct msi_chip *chip = irq_get_chip_data(irq);

	if (!chip || !chip->teardown_irq)
		return;

	chip->teardown_irq(chip, irq);
}

int __weak arch_msi_check_device(struct pci_dev *dev, int nvec, int type)
{
	struct msi_chip *chip = dev->bus->msi;

	if (!chip || !chip->check_device)
		return 0;

	return chip->check_device(chip, dev, nvec, type);
}

int __weak arch_setup_msi_irqs(struct pci_dev *dev, int nvec, int type)
{
	struct msi_desc *entry;
	int ret;

	/*
	 * If an architecture wants to support multiple MSI, it needs to
	 * override arch_setup_msi_irqs()
	 */
	if (type == PCI_CAP_ID_MSI && nvec > 1)
		return 1;

	list_for_each_entry(entry, &dev->msi_list, list) {
		ret = arch_setup_msi_irq(dev, entry);
		if (ret < 0)
			return ret;
		if (ret > 0)
			return -ENOSPC;
	}

	return 0;
}

/*
 * We have a default implementation available as a separate non-weak
 * function, as it is used by the Xen x86 PCI code
 */
void default_teardown_msi_irqs(struct pci_dev *dev)
{
	struct msi_desc *entry;

	list_for_each_entry(entry, &dev->msi_list, list) {
		int i, nvec;
		if (entry->irq == 0)
			continue;
		if (entry->nvec_used)
			nvec = entry->nvec_used;
		else
			nvec = 1 << entry->msi_attrib.multiple;
		for (i = 0; i < nvec; i++)
			arch_teardown_msi_irq(entry->irq + i);
	}
}

void __weak arch_teardown_msi_irqs(struct pci_dev *dev)
{
	return default_teardown_msi_irqs(dev);
}

static