a2a1c95c10
space. (!) Have each process use the kernel stack and pcb in the kvm space. Since the stacks are at a different address, we cannot copy the stack at fork() and allow the child to return up through the function call tree to return to user mode - create a new execution context and have the new process begin executing from cpu_switch() and go to user mode directly. In theory this should speed up fork a bit. Context switch the tss_esp0 pointer in the common tss. This is a lot simpler since than swithching the gdt[GPROC0_SEL].sd.sd_base pointer to each process's tss since the esp0 pointer is a 32 bit pointer, and the sd_base setting is split into three different bit sections at non-aligned boundaries and requires a lot of twiddling to reset. The 8K of memory at the top of the process space is now empty, and unmapped (and unmappable, it's higher than VM_MAXUSER_ADDRESS). Simplity the pmap code to manage process contexts, we no longer have to double map the UPAGES, this simplifies and should measuably speed up fork(). The following parts came from John Dyson: Set PG_G on the UPAGES that are now in kernel context, and invalidate them when swapping them out. Move the upages object (upobj) from the vmspace to the proc structure. Now that the UPAGES (pcb and kernel stack) are out of user space, make rfork(..RFMEM..) do what was intended by sharing the vmspace entirely via reference counting rather than simply inheriting the mappings.
285 lines
11 KiB
C
285 lines
11 KiB
C
/*
|
|
* Copyright (c) 1991, 1993
|
|
* The Regents of the University of California. All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to Berkeley by
|
|
* The Mach Operating System project at Carnegie-Mellon University.
|
|
*
|
|
* 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 the University of
|
|
* California, Berkeley and its contributors.
|
|
* 4. Neither the name of the University nor the names of its contributors
|
|
* may be used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
|
|
*
|
|
* @(#)vm_map.h 8.9 (Berkeley) 5/17/95
|
|
*
|
|
*
|
|
* Copyright (c) 1987, 1990 Carnegie-Mellon University.
|
|
* All rights reserved.
|
|
*
|
|
* Authors: Avadis Tevanian, Jr., Michael Wayne Young
|
|
*
|
|
* Permission to use, copy, modify and distribute this software and
|
|
* its documentation is hereby granted, provided that both the copyright
|
|
* notice and this permission notice appear in all copies of the
|
|
* software, derivative works or modified versions, and any portions
|
|
* thereof, and that both notices appear in supporting documentation.
|
|
*
|
|
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
|
|
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
|
|
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
|
|
*
|
|
* Carnegie Mellon requests users of this software to return to
|
|
*
|
|
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
|
|
* School of Computer Science
|
|
* Carnegie Mellon University
|
|
* Pittsburgh PA 15213-3890
|
|
*
|
|
* any improvements or extensions that they make and grant Carnegie the
|
|
* rights to redistribute these changes.
|
|
*
|
|
* $Id: vm_map.h,v 1.25 1997/04/06 02:29:44 dyson Exp $
|
|
*/
|
|
|
|
/*
|
|
* Virtual memory map module definitions.
|
|
*/
|
|
|
|
#ifndef _VM_MAP_
|
|
#define _VM_MAP_
|
|
|
|
/*
|
|
* Types defined:
|
|
*
|
|
* vm_map_t the high-level address map data structure.
|
|
* vm_map_entry_t an entry in an address map.
|
|
* vm_map_version_t a timestamp of a map, for use with vm_map_lookup
|
|
*/
|
|
|
|
/*
|
|
* Objects which live in maps may be either VM objects, or
|
|
* another map (called a "sharing map") which denotes read-write
|
|
* sharing with other maps.
|
|
*/
|
|
|
|
union vm_map_object {
|
|
struct vm_object *vm_object; /* object object */
|
|
struct vm_map *share_map; /* share map */
|
|
struct vm_map *sub_map; /* belongs to another map */
|
|
};
|
|
|
|
/*
|
|
* Address map entries consist of start and end addresses,
|
|
* a VM object (or sharing map) and offset into that object,
|
|
* and user-exported inheritance and protection information.
|
|
* Also included is control information for virtual copy operations.
|
|
*/
|
|
struct vm_map_entry {
|
|
struct vm_map_entry *prev; /* previous entry */
|
|
struct vm_map_entry *next; /* next entry */
|
|
vm_offset_t start; /* start address */
|
|
vm_offset_t end; /* end address */
|
|
union vm_map_object object; /* object I point to */
|
|
vm_ooffset_t offset; /* offset into object */
|
|
u_char eflags; /* map entry flags */
|
|
/* Only in task maps: */
|
|
vm_prot_t protection; /* protection code */
|
|
vm_prot_t max_protection; /* maximum protection */
|
|
vm_inherit_t inheritance; /* inheritance */
|
|
int wired_count; /* can be paged if = 0 */
|
|
};
|
|
|
|
#define MAP_ENTRY_IS_A_MAP 0x1
|
|
#define MAP_ENTRY_IS_SUB_MAP 0x2
|
|
#define MAP_ENTRY_COW 0x4
|
|
#define MAP_ENTRY_NEEDS_COPY 0x8
|
|
#define MAP_ENTRY_NOFAULT 0x10
|
|
#define MAP_ENTRY_USER_WIRED 0x20
|
|
|
|
/*
|
|
* Maps are doubly-linked lists of map entries, kept sorted
|
|
* by address. A single hint is provided to start
|
|
* searches again from the last successful search,
|
|
* insertion, or removal.
|
|
*/
|
|
struct vm_map {
|
|
struct pmap *pmap; /* Physical map */
|
|
struct lock lock; /* Lock for map data */
|
|
struct vm_map_entry header; /* List of entries */
|
|
int nentries; /* Number of entries */
|
|
vm_size_t size; /* virtual size */
|
|
boolean_t is_main_map; /* Am I a main map? */
|
|
int ref_count; /* Reference count */
|
|
struct simplelock ref_lock; /* Lock for ref_count field */
|
|
vm_map_entry_t hint; /* hint for quick lookups */
|
|
vm_map_entry_t first_free; /* First free space hint */
|
|
boolean_t entries_pageable; /* map entries pageable?? */
|
|
unsigned int timestamp; /* Version number */
|
|
#define min_offset header.start
|
|
#define max_offset header.end
|
|
};
|
|
|
|
/*
|
|
* Shareable process virtual address space.
|
|
* May eventually be merged with vm_map.
|
|
* Several fields are temporary (text, data stuff).
|
|
*/
|
|
struct vmspace {
|
|
struct vm_map vm_map; /* VM address map */
|
|
struct pmap vm_pmap; /* private physical map */
|
|
int vm_refcnt; /* number of references */
|
|
caddr_t vm_shm; /* SYS5 shared memory private data XXX */
|
|
/* we copy from vm_startcopy to the end of the structure on fork */
|
|
#define vm_startcopy vm_rssize
|
|
segsz_t vm_rssize; /* current resident set size in pages */
|
|
segsz_t vm_swrss; /* resident set size before last swap */
|
|
segsz_t vm_tsize; /* text size (pages) XXX */
|
|
segsz_t vm_dsize; /* data size (pages) XXX */
|
|
segsz_t vm_ssize; /* stack size (pages) */
|
|
caddr_t vm_taddr; /* user virtual address of text XXX */
|
|
caddr_t vm_daddr; /* user virtual address of data XXX */
|
|
caddr_t vm_maxsaddr; /* user VA at max stack growth */
|
|
caddr_t vm_minsaddr; /* user VA at max stack growth */
|
|
};
|
|
|
|
|
|
/*
|
|
* Map versions are used to validate a previous lookup attempt.
|
|
*
|
|
* Since lookup operations may involve both a main map and
|
|
* a sharing map, it is necessary to have a timestamp from each.
|
|
* [If the main map timestamp has changed, the share_map and
|
|
* associated timestamp are no longer valid; the map version
|
|
* does not include a reference for the embedded share_map.]
|
|
*/
|
|
typedef struct {
|
|
int main_timestamp;
|
|
vm_map_t share_map;
|
|
int share_timestamp;
|
|
} vm_map_version_t;
|
|
|
|
/*
|
|
* Macros: vm_map_lock, etc.
|
|
* Function:
|
|
* Perform locking on the data portion of a map.
|
|
*/
|
|
|
|
#define vm_map_lock_drain_interlock(map) { \
|
|
lockmgr(&(map)->lock, LK_DRAIN|LK_INTERLOCK, \
|
|
&(map)->ref_lock, curproc); \
|
|
(map)->timestamp++; \
|
|
}
|
|
#ifdef DIAGNOSTIC
|
|
#define vm_map_lock(map) { \
|
|
if (lockmgr(&(map)->lock, LK_EXCLUSIVE, (void *)0, curproc) != 0) { \
|
|
panic("vm_map_lock: failed to get lock"); \
|
|
} \
|
|
(map)->timestamp++; \
|
|
}
|
|
#else
|
|
#define vm_map_lock(map) { \
|
|
lockmgr(&(map)->lock, LK_EXCLUSIVE, (void *)0, curproc); \
|
|
(map)->timestamp++; \
|
|
}
|
|
#endif /* DIAGNOSTIC */
|
|
#define vm_map_unlock(map) \
|
|
lockmgr(&(map)->lock, LK_RELEASE, (void *)0, curproc)
|
|
#define vm_map_lock_read(map) \
|
|
lockmgr(&(map)->lock, LK_SHARED, (void *)0, curproc)
|
|
#define vm_map_unlock_read(map) \
|
|
lockmgr(&(map)->lock, LK_RELEASE, (void *)0, curproc)
|
|
#define vm_map_set_recursive(map) { \
|
|
simple_lock(&(map)->lock.lk_interlock); \
|
|
(map)->lock.lk_flags |= LK_CANRECURSE; \
|
|
simple_unlock(&(map)->lock.lk_interlock); \
|
|
}
|
|
#define vm_map_clear_recursive(map) { \
|
|
simple_lock(&(map)->lock.lk_interlock); \
|
|
(map)->lock.lk_flags &= ~LK_CANRECURSE; \
|
|
simple_unlock(&(map)->lock.lk_interlock); \
|
|
}
|
|
/*
|
|
* Functions implemented as macros
|
|
*/
|
|
#define vm_map_min(map) ((map)->min_offset)
|
|
#define vm_map_max(map) ((map)->max_offset)
|
|
#define vm_map_pmap(map) ((map)->pmap)
|
|
|
|
/* XXX: number of kernel maps and entries to statically allocate */
|
|
#define MAX_KMAP 10
|
|
#define MAX_KMAPENT 128
|
|
|
|
/*
|
|
* Copy-on-write flags for vm_map operations
|
|
*/
|
|
#define MAP_COPY_NEEDED 0x1
|
|
#define MAP_COPY_ON_WRITE 0x2
|
|
#define MAP_NOFAULT 0x4
|
|
|
|
/*
|
|
* vm_fault option flags
|
|
*/
|
|
#define VM_FAULT_NORMAL 0 /* Nothing special */
|
|
#define VM_FAULT_CHANGE_WIRING 1 /* Change the wiring as appropriate */
|
|
#define VM_FAULT_USER_WIRE 2 /* Likewise, but for user purposes */
|
|
#define VM_FAULT_WIRE_MASK (VM_FAULT_CHANGE_WIRING|VM_FAULT_USER_WIRE)
|
|
#define VM_FAULT_HOLD 4 /* Hold the page */
|
|
#define VM_FAULT_DIRTY 8 /* Dirty the page */
|
|
|
|
#ifdef KERNEL
|
|
extern vm_offset_t kentry_data;
|
|
extern vm_size_t kentry_data_size;
|
|
|
|
boolean_t vm_map_check_protection __P((vm_map_t, vm_offset_t, vm_offset_t, vm_prot_t));
|
|
int vm_map_copy __P((vm_map_t, vm_map_t, vm_offset_t, vm_size_t, vm_offset_t, boolean_t, boolean_t));
|
|
struct pmap;
|
|
vm_map_t vm_map_create __P((struct pmap *, vm_offset_t, vm_offset_t, boolean_t));
|
|
void vm_map_deallocate __P((vm_map_t));
|
|
int vm_map_delete __P((vm_map_t, vm_offset_t, vm_offset_t));
|
|
int vm_map_find __P((vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t *, vm_size_t, boolean_t, vm_prot_t, vm_prot_t, int));
|
|
int vm_map_findspace __P((vm_map_t, vm_offset_t, vm_size_t, vm_offset_t *));
|
|
int vm_map_inherit __P((vm_map_t, vm_offset_t, vm_offset_t, vm_inherit_t));
|
|
void vm_map_init __P((struct vm_map *, vm_offset_t, vm_offset_t, boolean_t));
|
|
int vm_map_insert __P((vm_map_t, vm_object_t, vm_ooffset_t, vm_offset_t, vm_offset_t, vm_prot_t, vm_prot_t, int));
|
|
int vm_map_lookup __P((vm_map_t *, vm_offset_t, vm_prot_t, vm_map_entry_t *, vm_object_t *,
|
|
vm_pindex_t *, vm_prot_t *, boolean_t *, boolean_t *));
|
|
void vm_map_lookup_done __P((vm_map_t, vm_map_entry_t));
|
|
boolean_t vm_map_lookup_entry __P((vm_map_t, vm_offset_t, vm_map_entry_t *));
|
|
int vm_map_pageable __P((vm_map_t, vm_offset_t, vm_offset_t, boolean_t));
|
|
int vm_map_user_pageable __P((vm_map_t, vm_offset_t, vm_offset_t, boolean_t));
|
|
int vm_map_clean __P((vm_map_t, vm_offset_t, vm_offset_t, boolean_t, boolean_t));
|
|
int vm_map_protect __P((vm_map_t, vm_offset_t, vm_offset_t, vm_prot_t, boolean_t));
|
|
void vm_map_reference __P((vm_map_t));
|
|
int vm_map_remove __P((vm_map_t, vm_offset_t, vm_offset_t));
|
|
void vm_map_simplify __P((vm_map_t, vm_offset_t));
|
|
void vm_map_startup __P((void));
|
|
int vm_map_submap __P((vm_map_t, vm_offset_t, vm_offset_t, vm_map_t));
|
|
void vm_map_madvise __P((vm_map_t, pmap_t, vm_offset_t, vm_offset_t, int));
|
|
void vm_map_simplify_entry __P((vm_map_t, vm_map_entry_t));
|
|
|
|
#endif
|
|
#endif /* _VM_MAP_ */
|