| 1 | /* $NetBSD: uvm_object.h,v 1.33 2012/09/14 22:20:50 rmind Exp $ */ |
| 2 | |
| 3 | /* |
| 4 | * Copyright (c) 1997 Charles D. Cranor and Washington University. |
| 5 | * All rights reserved. |
| 6 | * |
| 7 | * Redistribution and use in source and binary forms, with or without |
| 8 | * modification, are permitted provided that the following conditions |
| 9 | * are met: |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * 2. Redistributions in binary form must reproduce the above copyright |
| 13 | * notice, this list of conditions and the following disclaimer in the |
| 14 | * documentation and/or other materials provided with the distribution. |
| 15 | * |
| 16 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
| 17 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES |
| 18 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| 19 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, |
| 20 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 21 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| 22 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| 23 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 24 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF |
| 25 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 26 | * |
| 27 | * from: Id: uvm_object.h,v 1.1.2.2 1998/01/04 22:44:51 chuck Exp |
| 28 | */ |
| 29 | |
| 30 | #ifndef _UVM_UVM_OBJECT_H_ |
| 31 | #define _UVM_UVM_OBJECT_H_ |
| 32 | |
| 33 | #include <sys/queue.h> |
| 34 | #include <sys/rbtree.h> |
| 35 | #include <uvm/uvm_pglist.h> |
| 36 | |
| 37 | /* |
| 38 | * The UVM memory object interface. Notes: |
| 39 | * |
| 40 | * A UVM memory object represents a list of pages, which are managed by |
| 41 | * the object's pager operations (uvm_object::pgops). All pages belonging |
| 42 | * to an object are owned by it and thus protected by the object lock. |
| 43 | * |
| 44 | * The lock (uvm_object::vmobjlock) may be shared amongst the UVM objects. |
| 45 | * By default, the lock is allocated dynamically using mutex_obj(9) cache. |
| 46 | * Lock sharing is normally used when there is an underlying object. For |
| 47 | * example, vnode representing a file may have an underlying node, which |
| 48 | * is the case for tmpfs and layered file systems. In such case, vnode's |
| 49 | * UVM object and the underlying UVM object shares the lock (note that the |
| 50 | * vnode_t::v_interlock points to uvm_object::vmobjlock). |
| 51 | * |
| 52 | * The reference count is managed atomically for the anonymous UVM objects. |
| 53 | * For other objects, it is arbitrary (may use the lock or atomics). |
| 54 | */ |
| 55 | |
| 56 | struct uvm_object { |
| 57 | kmutex_t * vmobjlock; /* lock on memq */ |
| 58 | const struct uvm_pagerops *pgops; /* pager ops */ |
| 59 | struct pglist memq; /* pages in this object */ |
| 60 | int uo_npages; /* # of pages in memq */ |
| 61 | unsigned uo_refs; /* reference count */ |
| 62 | struct rb_tree rb_tree; /* tree of pages */ |
| 63 | LIST_HEAD(,ubc_map) uo_ubc; /* ubc mappings */ |
| 64 | }; |
| 65 | |
| 66 | /* |
| 67 | * UVM_OBJ_KERN is a 'special' uo_refs value which indicates that the |
| 68 | * object is a kernel memory object rather than a normal one (kernel |
| 69 | * memory objects don't have reference counts -- they never die). |
| 70 | * |
| 71 | * this value is used to detected kernel object mappings at uvm_unmap() |
| 72 | * time. normally when an object is unmapped its pages eventaully become |
| 73 | * deactivated and then paged out and/or freed. this is not useful |
| 74 | * for kernel objects... when a kernel object is unmapped we always want |
| 75 | * to free the resources associated with the mapping. UVM_OBJ_KERN |
| 76 | * allows us to decide which type of unmapping we want to do. |
| 77 | */ |
| 78 | #define UVM_OBJ_KERN (-2) |
| 79 | |
| 80 | #define UVM_OBJ_IS_KERN_OBJECT(uobj) \ |
| 81 | ((uobj)->uo_refs == UVM_OBJ_KERN) |
| 82 | |
| 83 | #ifdef _KERNEL |
| 84 | |
| 85 | extern const struct uvm_pagerops uvm_vnodeops; |
| 86 | extern const struct uvm_pagerops uvm_deviceops; |
| 87 | extern const struct uvm_pagerops ; |
| 88 | extern const struct uvm_pagerops ; |
| 89 | |
| 90 | #define UVM_OBJ_IS_VNODE(uobj) \ |
| 91 | ((uobj)->pgops == &uvm_vnodeops) |
| 92 | |
| 93 | #define UVM_OBJ_IS_DEVICE(uobj) \ |
| 94 | ((uobj)->pgops == &uvm_deviceops) |
| 95 | |
| 96 | #define UVM_OBJ_IS_VTEXT(uobj) \ |
| 97 | (UVM_OBJ_IS_VNODE(uobj) && uvn_text_p(uobj)) |
| 98 | |
| 99 | #define UVM_OBJ_IS_CLEAN(uobj) \ |
| 100 | (UVM_OBJ_IS_VNODE(uobj) && uvn_clean_p(uobj)) |
| 101 | |
| 102 | /* |
| 103 | * UVM_OBJ_NEEDS_WRITEFAULT: true if the uobj needs to detect modification. |
| 104 | * (ie. wants to avoid writable user mappings.) |
| 105 | * |
| 106 | * XXX bad name |
| 107 | */ |
| 108 | |
| 109 | #define UVM_OBJ_NEEDS_WRITEFAULT(uobj) \ |
| 110 | (UVM_OBJ_IS_VNODE(uobj) && uvn_needs_writefault_p(uobj)) |
| 111 | |
| 112 | #define UVM_OBJ_IS_AOBJ(uobj) \ |
| 113 | ((uobj)->pgops == &aobj_pager) |
| 114 | |
| 115 | extern const rb_tree_ops_t uvm_page_tree_ops; |
| 116 | |
| 117 | #endif /* _KERNEL */ |
| 118 | |
| 119 | #endif /* _UVM_UVM_OBJECT_H_ */ |
| 120 | |