/*-
 * This file is provided under a dual BSD/GPLv2 license. When using or
 * redistributing this file, you may do so under either license.
 *
 *   BSD LICENSE
 *
 * Copyright 2013-2016 Freescale Semiconductor Inc.
 * Copyright 2017 NXP.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * * Neither the name of the above-listed copyright holders nor the
 * names of any contributors may be used to endorse or promote products
 * derived from this software without specific prior written permission.
 *
 *   GPL LICENSE SUMMARY
 *
 * ALTERNATIVELY, this software may be distributed under the terms of the
 * GNU General Public License ("GPL") as published by the Free Software
 * Foundation, either version 2 of that License or (at your option) any
 * later version.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <process.h>
#include "dpaa_sys.h"

struct process_interrupt {
	int irq;
	irqreturn_t (*isr)(int irq, void *arg);
	unsigned long flags;
	const char *name;
	void *arg;
	struct list_head node;
};

static COMPAT_LIST_HEAD(process_irq_list);
static pthread_mutex_t process_irq_lock = PTHREAD_MUTEX_INITIALIZER;

static void process_interrupt_install(struct process_interrupt *irq)
{
	int ret;
	/* Add the irq to the end of the list */
	ret = pthread_mutex_lock(&process_irq_lock);
	assert(!ret);
	list_add_tail(&irq->node, &process_irq_list);
	ret = pthread_mutex_unlock(&process_irq_lock);
	assert(!ret);
}

static void process_interrupt_remove(struct process_interrupt *irq)
{
	int ret;

	ret = pthread_mutex_lock(&process_irq_lock);
	assert(!ret);
	list_del(&irq->node);
	ret = pthread_mutex_unlock(&process_irq_lock);
	assert(!ret);
}

static struct process_interrupt *process_interrupt_find(int irq_num)
{
	int ret;
	struct process_interrupt *i = NULL;

	ret = pthread_mutex_lock(&process_irq_lock);
	assert(!ret);
	list_for_each_entry(i, &process_irq_list, node) {
		if (i->irq == irq_num)
			goto done;
	}
done:
	ret = pthread_mutex_unlock(&process_irq_lock);
	assert(!ret);
	return i;
}

/* This is the interface from the platform-agnostic driver code to (de)register
 * interrupt handlers. We simply create/destroy corresponding structs.
 */
int qbman_request_irq(int irq, irqreturn_t (*isr)(int irq, void *arg),
		      unsigned long flags, const char *name,
		      void *arg __maybe_unused)
{
	struct process_interrupt *irq_node =
		kmalloc(sizeof(*irq_node), GFP_KERNEL);

	if (!irq_node)
		return -ENOMEM;
	irq_node->irq = irq;
	irq_node->isr = isr;
	irq_node->flags = flags;
	irq_node->name = name;
	irq_node->arg = arg;
	process_interrupt_install(irq_node);
	return 0;
}

int qbman_free_irq(int irq, __maybe_unused void *arg)
{
	struct process_interrupt *irq_node = process_interrupt_find(irq);

	if (!irq_node)
		return -EINVAL;
	process_interrupt_remove(irq_node);
	kfree(irq_node);
	return 0;
}

/* This is the interface from the platform-specific driver code to obtain
 * interrupt handlers that have been registered.
 */
void qbman_invoke_irq(int irq)
{
	struct process_interrupt *irq_node = process_interrupt_find(irq);

	if (irq_node)
		irq_node->isr(irq, irq_node->arg);
}