FreeBSD/Linux Kernel Cross Reference
sys/uvm/uvm_object.h

     /*      $OpenBSD: uvm_object.h,v 1.30 2022/09/04 06:49:11 jsg Exp $     */
     /*      $NetBSD: uvm_object.h,v 1.11 2001/03/09 01:02:12 chs Exp $      */
     
     /*
      * Copyright (c) 1997 Charles D. Cranor and Washington University.
      * 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 ``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 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.
     *
     * from: Id: uvm_object.h,v 1.1.2.2 1998/01/04 22:44:51 chuck Exp
     */
    
    #ifndef _UVM_UVM_OBJECT_H_
    #define _UVM_UVM_OBJECT_H_
    
    /*
     * The UVM memory object interface.  Notes:
     *
     * A UVM memory object represents a list of pages, which are managed by
     * the object's pager operations (uvm_object::pgops).  All pages belonging
     * to an object are owned by it and thus protected by the object lock.
     *
     * The lock (uvm_object::vmobjlock) may be shared amongst the UVM objects.
     * By default, the lock is allocated dynamically using rw_obj_init() cache.
     * Lock sharing is normally used when there is an underlying object.  For
     * example, vnode representing a file may have an underlying node, which
     * is the case for tmpfs and layered file systems.  In such case, vnode's
     * UVM object and the underlying UVM object shares the lock.
     *
     * The reference count is managed atomically for the anonymous UVM objects.
     * For other objects, it is arbitrary (may use the lock or atomics).
     */
    
    struct uvm_object {
            struct rwlock                   *vmobjlock;     /* lock on object */
            const struct uvm_pagerops       *pgops;         /* pager ops */
            RBT_HEAD(uvm_objtree, vm_page)   memt;          /* pages in object */
            int                              uo_npages;     /* # of pages in memt */
            int                              uo_refs;       /* reference count */
    };
    
    /*
     * UVM_OBJ_KERN is a 'special' uo_refs value which indicates that the
     * object is a kernel memory object rather than a normal one (kernel
     * memory objects don't have reference counts -- they never die).
     *
     * this value is used to detected kernel object mappings at uvm_unmap()
     * time.   normally when an object is unmapped its pages eventually become
     * deactivated and then paged out and/or freed.    this is not useful
     * for kernel objects... when a kernel object is unmapped we always want
     * to free the resources associated with the mapping.   UVM_OBJ_KERN
     * allows us to decide which type of unmapping we want to do.
     *
     * in addition, we have kernel objects which may be used in an
     * interrupt context.  these objects get their mappings entered
     * with pmap_kenter*() and removed with pmap_kremove(), which
     * are safe to call in interrupt context, and must be used ONLY
     * for wired kernel mappings in these objects and their associated
     * maps.
     */
    #define UVM_OBJ_KERN            (-2)
    
    #define UVM_OBJ_IS_KERN_OBJECT(uobj)                                    \
            ((uobj)->uo_refs == UVM_OBJ_KERN)
    
    #ifdef _KERNEL
    
    extern const struct uvm_pagerops uvm_vnodeops;
    extern const struct uvm_pagerops uvm_deviceops;
    extern const struct uvm_pagerops pmap_pager;
    extern const struct uvm_pagerops bufcache_pager;
    
    /* For object trees */
    int     uvm_pagecmp(const struct vm_page *, const struct vm_page *);
    RBT_PROTOTYPE(uvm_objtree, vm_page, objt, uvm_pagecmp)
    
    #define UVM_OBJ_IS_VNODE(uobj)                                          \
            ((uobj)->pgops == &uvm_vnodeops)
    
    #define UVM_OBJ_IS_DEVICE(uobj)                                         \
            ((uobj)->pgops == &uvm_deviceops)
   
   #define UVM_OBJ_IS_VTEXT(uobj)                                          \
           ((uobj)->pgops == &uvm_vnodeops &&                              \
            ((struct vnode *)uobj)->v_flag & VTEXT)
   
   #define UVM_OBJ_IS_AOBJ(uobj)                                           \
           ((uobj)->pgops == &aobj_pager)
   
   #define UVM_OBJ_IS_PMAP(uobj)                                           \
           ((uobj)->pgops == &pmap_pager)
   
   #define UVM_OBJ_IS_BUFCACHE(uobj)                                       \
           ((uobj)->pgops == &bufcache_pager)
   
   #define UVM_OBJ_IS_DUMMY(uobj)                                          \
           (UVM_OBJ_IS_PMAP(uobj) || UVM_OBJ_IS_BUFCACHE(uobj))
   
   void    uvm_obj_init(struct uvm_object *, const struct uvm_pagerops *, int);
   void    uvm_obj_destroy(struct uvm_object *);
   void    uvm_obj_setlock(struct uvm_object *, struct rwlock *);
   int     uvm_obj_wire(struct uvm_object *, voff_t, voff_t, struct pglist *);
   void    uvm_obj_unwire(struct uvm_object *, voff_t, voff_t);
   void    uvm_obj_free(struct uvm_object *);
   
   #endif /* _KERNEL */
   
   #endif /* _UVM_UVM_OBJECT_H_ */

Cache object: 8e5d700d5327a2bb5da6ec24e8764e3b