linux-imx

// SPDX-License-Identifier: GPL-2.0

/*

 *  linux/drivers/base/map.c

 *

 * (C) Copyright Al Viro 2002,2003

 *

 * NOTE: data structure needs to be changed.  It works, but for large dev_t

 * it will be too slow.  It is isolated, though, so these changes will be

 * local to that file.

 */

​

#include <linux/module.h>

#include <linux/slab.h>

#include <linux/mutex.h>

#include <linux/kdev_t.h>

#include <linux/kobject.h>

#include <linux/kobj_map.h>

​

struct kobj_map {

    struct probe {

        struct probe *next;

        dev_t dev;

        unsigned long range;

        struct module *owner;

        kobj_probe_t *get;

        int (*lock)(dev_t, void *);

        void *data;

    } *probes[255];

    struct mutex *lock;

};

​

int kobj_map(struct kobj_map *domain, dev_t dev, unsigned long range,

         struct module *module, kobj_probe_t *probe,

         int (*lock)(dev_t, void *), void *data)

{

    unsigned n = MAJOR(dev + range - 1) - MAJOR(dev) + 1;

    unsigned index = MAJOR(dev);

    unsigned i;

    struct probe *p;

​

    if (n > 255)

        n = 255;

​

    p = kmalloc_array(n, sizeof(struct probe), GFP_KERNEL);

    if (p == NULL)

        return -ENOMEM;

​

    for (i = 0; i < n; i++, p++) {

        p->owner = module;

        p->get = probe;

        p->lock = lock;

        p->dev = dev;

        p->range = range;

        p->data = data;

    }

    mutex_lock(domain->lock);

    for (i = 0, p -= n; i < n; i++, p++, index++) {

        struct probe **s = &domain->probes[index % 255];

        while (*s && (*s)->range < range)

            s = &(*s)->next;

        p->next = *s;

        *s = p;

    }