source: mainline/generic/include/mm/as.h@ 8d6bc2d5

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 8d6bc2d5 was 8d6bc2d5, checked in by Jakub Jermar <jakub@…>, 19 years ago

Reimplement memory sharing. Currently, only
anonymous address space areas can be shared.
  • Property mode set to 100644
File size: 6.5 KB
Line 
1/*
2 * Copyright (C) 2001-2004 Jakub Jermar
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#ifndef __AS_H__
30#define __AS_H__
31
32/** Address space area flags. */
33#define AS_AREA_READ 1
34#define AS_AREA_WRITE 2
35#define AS_AREA_EXEC 4
36#define AS_AREA_DEVICE 8
37#define AS_AREA_ANON 16
38
39#ifdef KERNEL
40
41#include <arch/mm/page.h>
42#include <arch/mm/as.h>
43#include <arch/mm/asid.h>
44#include <arch/types.h>
45#include <typedefs.h>
46#include <synch/spinlock.h>
47#include <synch/mutex.h>
48#include <adt/list.h>
49#include <adt/btree.h>
50
51/** Defined to be true if user address space and kernel address space shadow each other. */
52#define KERNEL_ADDRESS_SPACE_SHADOWED KERNEL_ADDRESS_SPACE_SHADOWED_ARCH
53
54#define KERNEL_ADDRESS_SPACE_START KERNEL_ADDRESS_SPACE_START_ARCH
55#define KERNEL_ADDRESS_SPACE_END KERNEL_ADDRESS_SPACE_END_ARCH
56#define USER_ADDRESS_SPACE_START USER_ADDRESS_SPACE_START_ARCH
57#define USER_ADDRESS_SPACE_END USER_ADDRESS_SPACE_END_ARCH
58
59#define IS_KA(addr) ((addr)>=KERNEL_ADDRESS_SPACE_START && (addr)<=KERNEL_ADDRESS_SPACE_END)
60
61#define USTACK_ADDRESS USTACK_ADDRESS_ARCH
62
63#define FLAG_AS_KERNEL (1 << 0) /**< Kernel address space. */
64
65/** Address space structure.
66 *
67 * as_t contains the list of as_areas of userspace accessible
68 * pages for one or more tasks. Ranges of kernel memory pages are not
69 * supposed to figure in the list as they are shared by all tasks and
70 * set up during system initialization.
71 */
72struct as {
73 /** Protected by asidlock. */
74 link_t inactive_as_with_asid_link;
75
76 mutex_t lock;
77
78 /** Number of processors on wich is this address space active. */
79 count_t refcount;
80
81 /** B+tree of address space areas. */
82 btree_t as_area_btree;
83
84 /** Page table pointer. Constant on architectures that use global page hash table. */
85 pte_t *page_table;
86
87 /** Address space identifier. Constant on architectures that do not support ASIDs.*/
88 asid_t asid;
89};
90
91struct as_operations {
92 pte_t *(* page_table_create)(int flags);
93 void (* page_table_lock)(as_t *as, bool lock);
94 void (* page_table_unlock)(as_t *as, bool unlock);
95};
96typedef struct as_operations as_operations_t;
97
98/** Address space area attributes. */
99#define AS_AREA_ATTR_NONE 0
100#define AS_AREA_ATTR_PARTIAL 1 /**< Not fully initialized area. */
101
102#define AS_PF_FAULT 0 /**< The page fault was not resolved by as_page_fault(). */
103#define AS_PF_OK 1 /**< The page fault was resolved by as_page_fault(). */
104#define AS_PF_DEFER 2 /**< The page fault was caused by memcpy_from_uspace()
105 or memcpy_to_uspace(). */
106
107typedef struct share_info share_info_t;
108typedef struct mem_backend mem_backend_t;
109
110/** Address space area structure.
111 *
112 * Each as_area_t structure describes one contiguous area of virtual memory.
113 * In the future, it should not be difficult to support shared areas.
114 */
115struct as_area {
116 mutex_t lock;
117 int flags; /**< Flags related to the memory represented by the address space area. */
118 int attributes; /**< Attributes related to the address space area itself. */
119 count_t pages; /**< Size of this area in multiples of PAGE_SIZE. */
120 __address base; /**< Base address of this area. */
121 btree_t used_space; /**< Map of used space. */
122 share_info_t *sh_info; /**< If the address space area has been shared, this pointer will
123 reference the share info structure. */
124 mem_backend_t *backend; /**< Memory backend backing this address space area. */
125 void *backend_data[2]; /**< Data to be used by the backend. */
126};
127
128/** Address space area backend structure. */
129struct mem_backend {
130 int (* backend_page_fault)(as_area_t *area, __address addr, pf_access_t access);
131 void (* backend_frame_free)(as_area_t *area, __address page, __address frame);
132};
133
134extern as_t *AS_KERNEL;
135extern as_operations_t *as_operations;
136
137extern spinlock_t as_lock;
138extern link_t inactive_as_with_asid_head;
139
140extern void as_init(void);
141extern as_t *as_create(int flags);
142extern as_area_t *as_area_create(as_t *as, int flags, size_t size, __address base, int attrs,
143 mem_backend_t *backend, void **backend_data);
144extern int as_area_resize(as_t *as, __address address, size_t size, int flags);
145extern int as_area_destroy(as_t *as, __address address);
146extern int as_area_get_flags(as_area_t *area);
147extern void as_set_mapping(as_t *as, __address page, __address frame);
148extern int as_page_fault(__address page, pf_access_t access, istate_t *istate);
149extern void as_switch(as_t *old, as_t *new);
150extern void as_free(as_t *as);
151extern int as_area_share(as_t *src_as, __address src_base, size_t acc_size, __address dst_base);
152extern size_t as_get_size(__address base);
153extern int used_space_insert(as_area_t *a, __address page, count_t count);
154extern int used_space_remove(as_area_t *a, __address page, count_t count);
155
156/* Interface to be implemented by architectures. */
157#ifndef as_install_arch
158extern void as_install_arch(as_t *as);
159#endif /* !def as_install_arch */
160
161/* Backend declarations. */
162extern mem_backend_t anon_backend;
163extern mem_backend_t elf_backend;
164
165/* Address space area related syscalls. */
166extern __native sys_as_area_create(__address address, size_t size, int flags);
167extern __native sys_as_area_resize(__address address, size_t size, int flags);
168extern __native sys_as_area_destroy(__address address);
169
170#endif /* KERNEL */
171
172#endif
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