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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/>.
*
*
* Virtual memory object.
*
* VM objects are the primary interface between a VM map and a pager. They
* can be entered in a VM map ("mapped") and, on page fault, the VM system
* requests the actual data from the the backing store pager. The physical
* pages used to store those data are then inserted into the appropriate
* object.
*/
#ifndef _VM_VM_OBJECT_H
#define _VM_VM_OBJECT_H
#include <kern/mutex.h>
#include <kern/rdxtree.h>
#include <kern/stdint.h>
struct vm_page;
struct vm_object_pager;
/*
* Memory object.
*/
struct vm_object {
struct mutex lock;
struct rdxtree pages;
unsigned long nr_pages;
struct vm_object_pager *pager;
};
/*
* Pager operations on an object.
*/
struct vm_object_pager {
void (*ref)(struct vm_object *object);
void (*unref)(struct vm_object *object);
int (*get)(struct vm_object *object, uint64_t offset,
struct vm_page **pagep);
};
static inline void
vm_object_init(struct vm_object *object, struct vm_object_pager *pager)
{
mutex_init(&object->lock);
rdxtree_init(&object->pages);
object->nr_pages = 0;
object->pager = pager;
}
/*
* Add a page at offset inside an object.
*/
int vm_object_add(struct vm_object *object, uint64_t offset,
struct vm_page *page);
/*
* Get the page at offset inside an object, or NULL if none is found.
*/
struct vm_page * vm_object_get(const struct vm_object *object, uint64_t offset);
#endif /* _VM_VM_OBJECT_H */
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