path: root/kernel/irq/msi.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2014 Intel Corp.
 * Author: Jiang Liu <jiang.liu@linux.intel.com>
 *
 * This file is licensed under GPLv2.
 *
 * This file contains common code to support Message Signaled Interrupts for
 * PCI compatible and non PCI compatible devices.
 */
#include <linux/types.h>
#include <linux/device.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/msi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/pci.h>

#include "internals.h"

static inline int msi_sysfs_create_group(struct device *dev);

/**
 * msi_alloc_desc - Allocate an initialized msi_desc
 * @dev:	Pointer to the device for which this is allocated
 * @nvec:	The number of vectors used in this entry
 * @affinity:	Optional pointer to an affinity mask array size of @nvec
 *
 * If @affinity is not %NULL then an affinity array[@nvec] is allocated
 * and the affinity masks and flags from @affinity are copied.
 *
 * Return: pointer to allocated &msi_desc on success or %NULL on failure
 */
static struct msi_desc *msi_alloc_desc(struct device *dev, int nvec,
					const struct irq_affinity_desc *affinity)
{
	struct msi_desc *desc = kzalloc(sizeof(*desc), GFP_KERNEL);

	if (!desc)
		return NULL;

	desc->dev = dev;
	desc->nvec_used = nvec;
	if (affinity) {
		desc->affinity = kmemdup(affinity, nvec * sizeof(*desc->affinity), GFP_KERNEL);
		if (!desc->affinity) {
			kfree(desc);
			return NULL;
		}
	}
	return desc;
}

static void msi_free_desc(struct msi_desc *desc)
{
	kfree(desc->affinity);
	kfree(desc);
}

static int msi_insert_desc(struct msi_device_data *md, struct msi_desc *desc, unsigned int index)
{
	int ret;

	desc->msi_index = index;
	ret = xa_insert(&md->__store, index, desc, GFP_KERNEL);
	if (ret)
		msi_free_desc(desc);
	return ret;
}

/**
 * msi_add_msi_desc - Allocate and initialize a MSI descriptor
 * @dev:	Pointer to the device for which the descriptor is allocated
 * @init_desc:	Pointer to an MSI descriptor to initialize the new descriptor
 *
 * Return: 0 on success or an appropriate failure code.
 */
int msi_add_msi_desc(struct device *dev, struct msi_desc *init_desc)
{
	struct msi_desc *desc;

	lockdep_assert_held(&dev->msi.data->mutex);

	desc = msi_alloc_desc(dev, init_desc->nvec_used, init_desc->affinity);
	if (!desc)
		return -ENOMEM;

	/* Copy type specific data to the new descriptor. */
	desc->pci = init_desc->pci;
	return msi_insert_desc(dev->msi.data, desc, init_desc->msi_index);
}

/**
 * msi_add_simple_msi_descs - Allocate and initialize MSI descriptors
 * @dev:	Pointer to the device for which the descriptors are allocated
 * @index:	Index for the first MSI descriptor
 * @ndesc:	Number of descriptors to allocate
 *
 * Return: 0 on success or an appropriate failure code.
 */
static int msi_add_simple_msi_descs(struct device *dev, unsigned int index, unsigned int ndesc)
{
	unsigned int idx, last = index + ndesc - 1;
	struct msi_desc *desc;
	int ret;

	lockdep_assert_held(&dev->msi.data->mutex);

	for (idx = index; idx <= last; idx++) {
		desc = msi_alloc_desc(dev, 1, NULL);
		if (!desc)
			goto fail_mem;
		ret = msi_insert_desc(dev->msi.data, desc, idx);
		if (ret)
			goto fail;
	}
	return 0;

fail_mem:
	ret = -ENOMEM;
fail:
	msi_free_msi_descs_range(dev, MSI_DESC_NOTASSOCIATED, index, last);
	return ret;
}

static bool msi_desc_match(struct msi_desc *desc, enum msi_desc_filter filter)
{
	switch (filter) {
	case MSI_DESC_ALL:
		return true;
	case MSI_DESC_NOTASSOCIATED:
		return !desc->irq;
	case MSI_DESC_ASSOCIATED:
		return !!desc->irq;
	}
	WARN_ON_ONCE(1);
	return false;
}

/**
 * msi_free_msi_descs_range - Free MSI descriptors of a device
 * @dev:		Device to free the descriptors
 * @filter:		Descriptor state filter
 * @first_index:	Index to start freeing from
 * @last_index:		Last index to be freed
 */
void msi_free_msi_descs_range(struct device *dev, enum msi_desc_filter filter,
			      unsigned int first_index, unsigned int last_index)
{
	struct xarray *xa = &dev->msi.data->__store;
	struct msi_desc *desc;
	unsigned long idx;

	lockdep_assert_held(&dev->msi.data->mutex);

	xa_for_each_range(xa, idx, desc, first_index, last_index) {
		if (msi_desc_match(desc, filter)) {
			xa_erase(xa, idx);
			msi_free_desc(desc);
		}
	}
}

void __get_cached_msi_msg(struct msi_desc *entry, struct msi_msg *msg)
{
	*msg = entry->msg;
}

void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
{
	struct msi_desc *entry = irq_get_msi_desc(irq);

	__get_cached_msi_msg(entry, msg);
}
EXPORT_SYMBOL_GPL(get_cached_msi_msg);

static void msi_device_data_release(struct device *dev, void *res)
{
	struct msi_device_data *md = res;

	WARN_ON_ONCE(!xa_empty(&md->__store));
	xa_destroy(&md->__store);
	dev->msi.data = NULL;
}

/**
 * msi_setup_device_data - Setup MSI device data
 * @dev:	Device for which MSI de