/* $NetBSD: uvm_object.h,v 1.39 2020/08/14 09:06:15 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_ #include #include #include /* * 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 mutex_obj(9) 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 (note that the * vnode_t::v_interlock points to uvm_object::vmobjlock). * * The reference count is managed atomically for the anonymous UVM objects. * For other objects, it is arbitrary (may use the lock or atomics). */ struct krwlock; struct uvm_object { struct krwlock * vmobjlock; /* lock on object */ const struct uvm_pagerops *pgops; /* pager ops */ int uo_npages; /* # of pages in uo_pages */ unsigned uo_refs; /* reference count */ struct radix_tree uo_pages; /* tree of pages */ LIST_HEAD(,ubc_map) uo_ubc; /* ubc mappings */ }; /* * tags for uo_pages */ #define UVM_PAGE_DIRTY_TAG 1 /* might be dirty (!PG_CLEAN) */ #define UVM_PAGE_WRITEBACK_TAG 2 /* being written back */ /* * 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 eventaully 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. */ #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 ubc_pager; extern const struct uvm_pagerops aobj_pager; #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) \ (UVM_OBJ_IS_VNODE(uobj) && uvn_text_p(uobj)) #define UVM_OBJ_IS_CLEAN(uobj) \ (UVM_OBJ_IS_VNODE(uobj) && uvm_obj_clean_p(uobj)) /* * UVM_OBJ_NEEDS_WRITEFAULT: true if the uobj needs to detect modification. * (ie. wants to avoid writable user mappings.) * * XXX bad name */ #define UVM_OBJ_NEEDS_WRITEFAULT(uobj) \ (UVM_OBJ_IS_VNODE(uobj) && uvm_obj_clean_p(uobj)) #define UVM_OBJ_IS_AOBJ(uobj) \ ((uobj)->pgops == &aobj_pager) #endif /* _KERNEL */ #endif /* _UVM_UVM_OBJECT_H_ */