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/*
* Copyright (c) 2013 Richard Braun.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <kern/error.h>
#include <kern/init.h>
#include <kern/kmem.h>
#include <kern/list.h>
#include <kern/llsync.h>
#include <kern/macros.h>
#include <kern/mutex.h>
#include <kern/panic.h>
#include <kern/stddef.h>
#include <kern/stdint.h>
#include <vm/vm_anon.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_phys.h>
/*
* Anonymous memory container.
*/
struct vm_anon {
struct vm_object object;
unsigned long nr_refs;
size_t size;
};
/*
* Anonymous pager operations.
*/
static void vm_anon_ref(struct vm_object *object);
static void vm_anon_unref(struct vm_object *object);
static int vm_anon_get(struct vm_object *object, uint64_t offset,
struct vm_page **pagep);
static struct vm_object_pager vm_anon_pager = {
.ref = vm_anon_ref,
.unref = vm_anon_unref,
.get = vm_anon_get,
};
static struct kmem_cache vm_anon_cache;
void __init
vm_anon_setup(void)
{
kmem_cache_init(&vm_anon_cache, "vm_anon", sizeof(struct vm_anon), 0,
NULL, NULL, NULL, 0);
}
struct vm_object *
vm_anon_create(size_t size)
{
struct vm_anon *anon;
anon = kmem_cache_alloc(&vm_anon_cache);
if (anon == NULL)
return NULL;
vm_object_init(&anon->object, &vm_anon_pager);
anon->nr_refs = 1;
anon->size = size;
return &anon->object;
}
static void
vm_anon_ref(struct vm_object *object)
{
struct vm_anon *anon;
anon = structof(object, struct vm_anon, object);
/* TODO Use atomic operations */
mutex_lock(&anon->object.lock);
anon->nr_refs++;
mutex_unlock(&anon->object.lock);
}
static void
vm_anon_unref(struct vm_object *object)
{
struct vm_anon *anon;
unsigned int nr_refs;
anon = structof(object, struct vm_anon, object);
mutex_lock(&anon->object.lock);
anon->nr_refs--;
nr_refs = anon->nr_refs;
mutex_unlock(&anon->object.lock);
if (nr_refs == 0)
panic("vm_anon: destruction not implemented");
}
static int
vm_anon_get(struct vm_object *object, uint64_t offset,
struct vm_page **pagep)
{
struct vm_page *page;
int error;
page = vm_phys_alloc(0);
if (page == NULL)
return ERROR_NOMEM;
error = vm_object_add(object, offset, page);
if (error)
goto error_object;
*pagep = page;
return 0;
error_object:
vm_phys_free(page, 0);
return error;
}
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