NetBSD/sys/uvm/uvm_amap.h

141 lines
5.3 KiB
C

/* $NetBSD: uvm_amap.h,v 1.6 1998/03/09 00:58:56 mrg Exp $ */
/*
* XXXCDC: "ROUGH DRAFT" QUALITY UVM PRE-RELEASE FILE!
* >>>USE AT YOUR OWN RISK, WORK IS NOT FINISHED<<<
*/
/*
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Charles D. Cranor and
* Washington University.
* 4. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* 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_amap.h,v 1.1.2.7 1998/01/05 18:12:56 chuck Exp
*/
#ifndef _UVM_UVM_AMAP_H_
#define _UVM_UVM_AMAP_H_
/*
* uvm_amap.h
*/
/*
* defines for handling of large sparce amaps.
*
* currently the kernel likes to allocate large chunks of VM to reserve
* them for possible use. for example, it allocates (reserves) a large
* chunk of user VM for possible stack growth. most of the time only
* a page or two of this VM is actually used. since the stack is anonymous
* memory it makes sense for it to live in an amap, but if we allocated
* an amap for the entire stack range we could end up wasting a large
* amount of malloc'd KVM.
*
* for example, on the i386 at boot time we allocate two amaps for the stack
* of /sbin/init:
* 1. a 7680 slot amap at protection 0 (reserve space for stack)
* 2. a 512 slot amap at protection 7 (top of stack)
*
* most of that VM is never mapped or used.
*
* to avoid allocating amap resources for the whole range we have the
* VM system look for maps that are larger than UVM_AMAP_LARGE slots
* (note that 1 slot = 1 vm_page). for maps that are large, we attempt
* to break them up into UVM_AMAP_CHUNK slot sized amaps.
*
* so, in the i386 example, the 7680 slot area is never referenced so
* nothing gets allocated. the 512 slot area is referenced, and it
* gets divided into 16 slot chunks (hopefully with one 16 slot chunk
* being enough to handle the whole stack...).
*/
#define UVM_AMAP_LARGE 256 /* # of slots in "large" amap */
#define UVM_AMAP_CHUNK 16 /* # of slots to chunk large amaps in */
#ifdef DIAGNOSTIC
#define AMAP_B2SLOT(S,B) { \
if ((B) % PAGE_SIZE) \
panic("AMAP_B2SLOT: invalid byte count"); \
(S) = (B) / PAGE_SIZE; \
}
#else
#define AMAP_B2SLOT(S,B) (S) = (B) / PAGE_SIZE
#endif
#ifdef VM_AMAP_PPREF
#define PPREF_NONE ((int *) -1)
#endif
/*
* handle inline options
*/
#ifdef UVM_AMAP_INLINE
#define AMAP_INLINE static __inline
#else
#define AMAP_INLINE /* nothing */
#endif /* UVM_AMAP_INLINE */
/*
* prototypes: the following prototypes define the interface to amaps
*/
AMAP_INLINE vm_offset_t amap_add __P((struct vm_aref *, vm_offset_t,
struct vm_anon *, int));
struct vm_amap *amap_alloc __P((vm_offset_t, vm_offset_t, int));
void amap_copy __P((vm_map_t, vm_map_entry_t, int, boolean_t,
vm_offset_t, vm_offset_t));
void amap_cow_now __P((vm_map_t, vm_map_entry_t));
void amap_extend __P((vm_map_entry_t, vm_size_t));
void amap_free __P((struct vm_amap *));
AMAP_INLINE struct vm_anon *amap_lookup __P((struct vm_aref *, vm_offset_t));
AMAP_INLINE void amap_lookups __P((struct vm_aref *, vm_offset_t,
struct vm_anon **, int));
#ifdef VM_AMAP_PPREF
void amap_pp_adjref __P((struct vm_amap *, int, vm_size_t, int));
void amap_pp_establish __P((struct vm_amap *));
#endif
AMAP_INLINE void amap_ref __P((vm_map_entry_t, int));
void amap_share_protect __P((vm_map_entry_t, vm_prot_t));
void amap_splitref __P((struct vm_aref *, struct vm_aref *, vm_offset_t));
AMAP_INLINE void amap_unadd __P((struct vm_amap *, vm_offset_t));
AMAP_INLINE void amap_unref __P((vm_map_entry_t, int));
void amap_wipeout __P((struct vm_amap *));
#ifdef VM_AMAP_PPREF
void amap_wiperange __P((struct vm_amap *, int, int));
#endif
struct vm_anon *uvm_analloc __P((void));
void uvm_anfree __P((struct vm_anon *));
void uvm_anon_init __P((void));
void uvm_anon_add __P((int));
struct vm_page *uvm_anon_lockloanpg __P((struct vm_anon *));
#endif /* _UVM_UVM_AMAP_H_ */