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/*
* Copyright (c) 2023-2024 Ian Marco Moffett and the Osmora Team.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name of Hyra nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* 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 OWNER 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 <sys/device.h>
#include <sys/queue.h>
#include <sys/errno.h>
#include <sys/types.h>
#include <sys/spinlock.h>
static TAILQ_HEAD(, device) devices;
static struct spinlock devices_lock = {0};
static bool device_list_init = false;
dev_t
device_alloc_major(void)
{
static dev_t major = 1;
return major++;
}
struct device *
device_fetch(dev_t major, dev_t minor)
{
struct device *dev;
TAILQ_FOREACH(dev, &devices, link) {
if (dev->major == major && dev->minor == minor) {
return dev;
}
}
return NULL;
}
dev_t
device_create(struct device *dev, dev_t major, dev_t minor)
{
if (dev == NULL || minor == 0) {
return -EINVAL;
}
if (major == 0) {
return -EINVAL;
}
if (!device_list_init) {
TAILQ_INIT(&devices);
device_list_init = true;
}
dev->major = major;
dev->minor = minor;
spinlock_acquire(&devices_lock);
TAILQ_INSERT_HEAD(&devices, dev, link);
spinlock_release(&devices_lock);
return dev->major;
}
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