/*-
* Copyright (c) 2000,2003 Doug Rabson
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/kernel.h>
#include <sys/kobj.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/sysctl.h>
#ifndef TEST
#include <sys/systm.h>
#endif
#ifdef TEST
#include "usertest.h"
#endif
static MALLOC_DEFINE(M_KOBJ, "kobj", "Kernel object structures");
#ifdef KOBJ_STATS
u_int kobj_lookup_hits;
u_int kobj_lookup_misses;
SYSCTL_UINT(_kern, OID_AUTO, kobj_hits, CTLFLAG_RD,
&kobj_lookup_hits, 0, "");
SYSCTL_UINT(_kern, OID_AUTO, kobj_misses, CTLFLAG_RD,
&kobj_lookup_misses, 0, "");
#endif
static struct mtx kobj_mtx;
static int kobj_mutex_inited;
static int kobj_next_id = 1;
/*
* In the event that kobj_mtx has not been initialized yet,
* we will ignore it, and run without locks in order to support
* use of KOBJ before mutexes are available. This early in the boot
* process, everything is single threaded and so races should not
* happen. This is used to provide the PMAP layer on PowerPC, as well
* as board support.
*/
#define KOBJ_LOCK() if (kobj_mutex_inited) mtx_lock(&kobj_mtx);
#define KOBJ_UNLOCK() if (kobj_mutex_inited) mtx_unlock(&kobj_mtx);
#define KOBJ_ASSERT(what) if (kobj_mutex_inited) mtx_assert(&kobj_mtx,what);
SYSCTL_INT(_kern, OID_AUTO, kobj_methodcount, CTLFLAG_RD,
&kobj_next_id, 0, "");
static void
kobj_init_mutex(void *arg)
{
if (!kobj_mutex_inited) {
mtx_init(&kobj_mtx, "kobj", NULL, MTX_DEF);
kobj_mutex_inited = 1;
}
}
SYSINIT(kobj, SI_SUB_LOCK, SI_ORDER_ANY, kobj_init_mutex, NULL);
/*
* This method structure is used to initialise new caches. Since the
* desc pointer is NULL, it is guaranteed never to match any read
* descriptors.
*/
static struct kobj_method null_method = {
0, 0,
};
int
kobj_error_method(void)
{
return ENXIO;
}
static void
kobj_register_method(struct kobjop_desc *desc)
{
KOBJ_ASSERT(MA_OWNED);
if (desc->id == 0) {
desc->id = kobj_next_id++;
}
}
static void
kobj_unregister_method(struct kobjop_desc *desc)
{
}
static void
kobj_class_compile_common(kobj_class_t cls, kobj_ops_t ops)
{
kobj_method_t *m;
int i;
KOBJ_ASSERT(MA_OWNED);
/*
* Don't do anything if we are already compiled.
*/
if (cls->ops)
return;
/*
* First register any methods which need it.
*/
for (i = 0, m = cls->methods; m->desc; i++, m++)
kobj_register_method(m->desc);
/*
* Then initialise the ops table.
*/
for (i = 0; i < KOBJ_CACHE_SIZE; i++)
ops->cache[i] = &null_method;
ops->cls = cls;
cls->ops = ops;
}
void
kobj_class_compile(kobj_class_t cls)
{
kobj_ops_t ops;
KOBJ_ASSERT(MA_NOTOWNED);
/*
* Allocate space for the compiled ops table.
*/
ops = malloc(sizeof(struct kobj_ops), M_KOBJ, M_NOWAIT);
if (!ops)
panic("kobj_compile_methods: out of memory");
KOBJ_LOCK();
/*
* We may have lost a race for kobj_class_compile here - check
* to make sure someone else hasn't already compiled this
* class.
*/
if (cls->ops) {
KOBJ_UNLOCK();
free(ops, M_KOBJ);
return;
}
kobj_class_compile_common(cls, ops);
KOBJ_UNLOCK();
}
void
kobj_class_compile_static(kobj_class_t cls, kobj_ops_t ops)
{
KOBJ_ASSERT(MA_NOTOWNED);
/*
* Increment refs to make sure that the ops table is not freed.
*/
KOBJ_LOCK();
cls->refs++;
kobj_class_compile_common(cls, ops);
KOBJ_UNLOCK();
}
static kobj_method_t*
kobj_lookup_method_class(kobj_class_t cls, kobjop_desc_t desc)
{
kobj_method_t *methods = cls->methods;
kobj_method_t *ce;
for (ce = methods; ce && ce->desc; ce++) {
if (ce->desc == desc) {
return ce;
}
}
return NULL;
}
static kobj_method_t*
kobj_lookup_method_mi(kobj_class_t cls,
kobjop_desc_t desc)
{
kobj_method_t *ce;
kobj_class_t *basep;
ce = kobj_lookup_method_class(cls, desc);
if (ce)
return ce;
basep = cls->baseclasses;
if (basep) {
for (; *basep; basep++) {
ce = kobj_lookup_method_mi(*basep, desc);
if (ce)
return ce;
}
}
return NULL;
}
kobj_method_t*
kobj_lookup_method(kobj_class_t cls,
kobj_method_t **cep,
kobjop_desc_t desc)
{
kobj_method_t *ce;
#ifdef KOBJ_STATS
/*
* Correct for the 'hit' assumption in KOBJOPLOOKUP and record
* a 'miss'.
*/
kobj_lookup_hits--;
kobj_lookup_misses++;
#endif
ce = kobj_lookup_method_mi(cls, desc);
if (!ce)
ce = desc->deflt;
*cep = ce;
return ce;
}
void
kobj_class_free(kobj_class_t cls)
{
int i;
kobj_method_t *m;
void* ops = NULL;
KOBJ_ASSERT(MA_NOTOWNED);
KOBJ_LOCK();
/*
* Protect against a race between kobj_create and
* kobj_delete.
*/
if (cls->refs == 0) {
/*
* Unregister any methods which are no longer used.
*/
for (i = 0, m = cls->methods; m->desc; i++, m++)
kobj_unregister_method(m->desc);
/*
* Free memory and clean up.
*/
ops = cls->ops;
cls->ops = NULL;
}
KOBJ_UNLOCK();
if (ops)
free(ops, M_KOBJ);
}
kobj_t
kobj_create(kobj_class_t cls,
struct malloc_type *mtype,
int mflags)
{
kobj_t obj;
/*
* Allocate and initialise the new object.
*/
obj = malloc(cls->size, mtype, mflags | M_ZERO);
if (!obj)
return NULL;
kobj_init(obj, cls);
return obj;
}
void
kobj_init(kobj_t obj, kobj_class_t cls)
{
KOBJ_ASSERT(MA_NOTOWNED);
retry:
KOBJ_LOCK();
/*
* Consider compiling the class' method table.
*/
if (!cls->ops) {
/*
* kobj_class_compile doesn't want the lock held
* because of the call to malloc - we drop the lock
* and re-try.
*/
KOBJ_UNLOCK();
kobj_class_compile(cls);
goto retry;
}
obj->ops = cls->ops;
cls->refs++;
KOBJ_UNLOCK();
}
void
kobj_delete(kobj_t obj, struct malloc_type *mtype)
{
kobj_class_t cls = obj->ops->cls;
int refs;
/*
* Consider freeing the compiled method table for the class
* after its last instance is deleted. As an optimisation, we
* should defer this for a short while to avoid thrashing.
*/
KOBJ_ASSERT(MA_NOTOWNED);
KOBJ_LOCK();
cls->refs--;
refs = cls->refs;
KOBJ_UNLOCK();
if (!refs)
kobj_class_free(cls);
obj->ops = NULL;
if (mtype)
free(obj, mtype);
}
