include/vm/object.h

   1 /*
   2  * Copyright 2017 Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
   3  *
   4  * Permission to use, copy, modify, and/or distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #ifndef _VM_OBJECT_H
  18 #define _VM_OBJECT_H
  19
  20 #include <sys/list.h>
  21 #include <sys/avl.h>
  22
  23 #ifdef  __cplusplus
  24 extern "C" {
  25 #endif
  26
  27 struct vnode;
  28
  29 struct vmobject {
  30         /*
  31          * We keep all the pages in an AVL tree indexed by the offset.  This
  32          * allows us to do quick offset lookups.
  33          *
  34          * We also keep all the pages on a list, which we use during
  35          * eviction.
  36          */
  37         avl_tree_t      tree;
  38         list_t          list;
  39
  40         kmutex_t        lock;
  41
  42         struct vnode    *vnode;         /* the owner */
  43 };
  44
  45 #if defined(_KERNEL)
  46 #define vmobject_add_page_head(o,p)     list_insert_head(&(o)->list, (p))
  47 #define vmobject_add_page_tail(o,p)     list_insert_tail(&(o)->list, (p))
  48 #define vmobject_remove_page(o,p)       list_remove(&(o)->list, (p))
  49 #define vmobject_get_head(o)            list_head(&(o)->list)
  50 #define vmobject_get_tail(o)            list_tail(&(o)->list)
  51 #define vmobject_get_prev(o,p)          list_prev(&(o)->list, (p))
  52 #define vmobject_get_next(o,p)          list_next(&(o)->list, (p))
  53
  54 static inline struct page *
  55 vmobject_get_prev_loop(struct vmobject *obj, struct page *page)
  56 {
  57         struct page *p;
  58
  59         p = vmobject_get_prev(obj, page);
  60         if (p == NULL)
  61                 p = vmobject_get_tail(obj);
  62
  63         return (p);
  64 }
  65
  66 static inline struct page *
  67 vmobject_get_next_loop(struct vmobject *obj, struct page *page)
  68 {
  69         struct page *p;
  70
  71         p = vmobject_get_next(obj, page);
  72         if (p == NULL)
  73                 p = vmobject_get_head(obj);
  74
  75         return (p);
  76 }
  77
  78 static inline void
  79 vmobject_move_page_tail(struct vmobject *obj, struct page *page)
  80 {
  81         vmobject_remove_page(obj, page);
  82         vmobject_add_page_tail(obj, page);
  83 }
  84
  85 #define VMOBJECT_LOCKED(obj)    MUTEX_HELD(&(obj)->lock)
  86
  87 static inline void
  88 vmobject_lock(struct vmobject *obj)
  89 {
  90         mutex_enter(&obj->lock);
  91 }
  92
  93 static inline int
  94 vmobject_trylock(struct vmobject *obj)
  95 {
  96         return mutex_tryenter(&obj->lock);
  97 }
  98
  99 static inline void
 100 vmobject_unlock(struct vmobject *obj)
 101 {
 102         mutex_exit(&obj->lock);
 103 }
 104
 105 extern void vmobject_init(struct vmobject *obj, struct vnode *vnode);
 106 extern void vmobject_fini(struct vmobject *obj);
 107
 108 #endif
 109
 110 #ifdef  __cplusplus
 111 }
 112 #endif
 113
 114 #endif