155 lines
3.3 KiB
C
155 lines
3.3 KiB
C
// 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 int n = MAJOR(dev + range - 1) - MAJOR(dev) + 1;
|
|
unsigned int index = MAJOR(dev);
|
|
unsigned int 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;
|
|
}
|
|
mutex_unlock(domain->lock);
|
|
return 0;
|
|
}
|
|
|
|
void kobj_unmap(struct kobj_map *domain, dev_t dev, unsigned long range)
|
|
{
|
|
unsigned int n = MAJOR(dev + range - 1) - MAJOR(dev) + 1;
|
|
unsigned int index = MAJOR(dev);
|
|
unsigned int i;
|
|
struct probe *found = NULL;
|
|
|
|
if (n > 255)
|
|
n = 255;
|
|
|
|
mutex_lock(domain->lock);
|
|
for (i = 0; i < n; i++, index++) {
|
|
struct probe **s;
|
|
for (s = &domain->probes[index % 255]; *s; s = &(*s)->next) {
|
|
struct probe *p = *s;
|
|
if (p->dev == dev && p->range == range) {
|
|
*s = p->next;
|
|
if (!found)
|
|
found = p;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
mutex_unlock(domain->lock);
|
|
kfree(found);
|
|
}
|
|
|
|
struct kobject *kobj_lookup(struct kobj_map *domain, dev_t dev, int *index)
|
|
{
|
|
struct kobject *kobj;
|
|
struct probe *p;
|
|
unsigned long best = ~0UL;
|
|
|
|
retry:
|
|
mutex_lock(domain->lock);
|
|
for (p = domain->probes[MAJOR(dev) % 255]; p; p = p->next) {
|
|
struct kobject *(*probe)(dev_t, int *, void *);
|
|
struct module *owner;
|
|
void *data;
|
|
|
|
if (p->dev > dev || p->dev + p->range - 1 < dev)
|
|
continue;
|
|
if (p->range - 1 >= best)
|
|
break;
|
|
if (!try_module_get(p->owner))
|
|
continue;
|
|
owner = p->owner;
|
|
data = p->data;
|
|
probe = p->get;
|
|
best = p->range - 1;
|
|
*index = dev - p->dev;
|
|
if (p->lock && p->lock(dev, data) < 0) {
|
|
module_put(owner);
|
|
continue;
|
|
}
|
|
mutex_unlock(domain->lock);
|
|
kobj = probe(dev, index, data);
|
|
/* Currently ->owner protects _only_ ->probe() itself. */
|
|
module_put(owner);
|
|
if (kobj)
|
|
return kobj;
|
|
goto retry;
|
|
}
|
|
mutex_unlock(domain->lock);
|
|
return NULL;
|
|
}
|
|
|
|
struct kobj_map *kobj_map_init(kobj_probe_t *base_probe, struct mutex *lock)
|
|
{
|
|
struct kobj_map *p = kmalloc(sizeof(struct kobj_map), GFP_KERNEL);
|
|
struct probe *base = kzalloc(sizeof(*base), GFP_KERNEL);
|
|
int i;
|
|
|
|
if ((p == NULL) || (base == NULL)) {
|
|
kfree(p);
|
|
kfree(base);
|
|
return NULL;
|
|
}
|
|
|
|
base->dev = 1;
|
|
base->range = ~0;
|
|
base->get = base_probe;
|
|
for (i = 0; i < 255; i++)
|
|
p->probes[i] = base;
|
|
p->lock = lock;
|
|
return p;
|
|
}
|