source: trunk/kernel/mm/page.h @ 657

Last change on this file since 657 was 656, checked in by alain, 6 years ago

Fix several bugs in the FATFS and in the VFS,
related to the creation of big files requiring
more than 4 Kbytes (one cluster) on device.
File size: 10.6 KB
Line 
1/*
2 * page.h - physical page descriptor and related operations
3 *
4 * Authors Ghassan Almalles (2008,2009,2010,2011,2012)
5 *         Alain Greiner    (2016,2017,2018,2019)
6 *
7 * Copyright (c) UPMC Sorbonne Universites
8 *
9 * This file is part of ALMOS-MKH.
10 *
11 * ALMOS-MKH is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by
13 * the Free Software Foundation; version 2.0 of the License.
14 *
15 * ALMOS-MKH is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with ALMOS-MKH; if not, write to the Free Software Foundation,
22 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
23 */
24
25#ifndef _PAGE_H_
26#define _PAGE_H_
27
28#include <kernel_config.h>
29#include <hal_kernel_types.h>
30#include <remote_busylock.h>
31#include <list.h>
32
33/***   Forward declarations   ***/
34
35struct mapper_s;
36
37/*************************************************************************************
38 * This  defines the flags that can be attached to a physical page.
39 ************************************************************************************/
40
41#define PG_INIT             0x0001     // page descriptor has been initialised
42#define PG_RESERVED         0x0002     // cannot be allocated by PPM
43#define PG_FREE             0x0004     // page not yet allocated by PPM
44#define PG_DIRTY            0x0040     // page has been written
45#define PG_COW          0x0080     // page is copy-on-write
46
47/*************************************************************************************
48 * This structure defines a physical page descriptor.
49 * - The remote_busylock is used to allows any remote thread to atomically
50 *   test/modify the forks counter or the flags.
51 * - The list field is used to register the page in a free list, or in dirty list,
52 *   as a given page cannot be simultaneously dirty and free.
53 * - The refcount is used to release the page to the PPM.
54 * NOTE: the size is 48 bytes for a 32 bits core.
55 ************************************************************************************/
56
57typedef struct page_s
58{
59    uint32_t          flags;          /*! flags defined above                  (4)  */
60    uint32_t          order;          /*! log2( number of small pages)         (4)  */
61    struct mapper_s * mapper;         /*! local pointer on associated mapper   (4)  */
62    uint32_t          index;          /*! page index in mapper                 (4)  */
63        list_entry_t      list;           /*! for both dirty pages and free pages  (8)  */
64        int32_t           refcount;       /*! references counter for page release  (4)  */
65        uint32_t          forks;          /*! number of pending forks              (4)  */
66        remote_busylock_t lock;           /*! protect forks or flags modifs        (16) */
67}
68page_t;
69
70/*************************************************************************************
71 * This function must be called by a thread running in the local cluster.
72 * It initializes the page descriptor.
73 *************************************************************************************
74 * @ page    : pointer to page descriptor
75 ************************************************************************************/
76inline void page_init( page_t * page );
77
78/*************************************************************************************
79 * This function must be called by a thread running in the local cluster.
80 * It atomically set one or several flags in page descriptor flags.
81 *************************************************************************************
82 * @ page    : pointer to page descriptor.
83 * @ value   : all non zero bits in value will be set.
84 ************************************************************************************/
85inline void page_set_flag( page_t   * page,
86                           uint32_t   value );
87
88/*************************************************************************************
89 * This function must be called by a thread running in the local cluster.
90 * It atomically reset one or several flags in page descriptor flags.
91 *************************************************************************************
92 * @ page    : pointer to page descriptor.
93 * @ value   : all non zero bits in value will be cleared.
94 ************************************************************************************/
95inline void page_clear_flag( page_t   * page,
96                             uint32_t   value );
97
98/*************************************************************************************
99 * This function must be called by a thread running in the local cluster.
100 * It tests the value of one or several flags in page descriptor flags.
101 *************************************************************************************
102 * @ page    : pointer to page descriptor.
103 * @ value   : all non zero bits will be tested.
104 * @ returns true if at least one non zero bit in value is set / false otherwise.
105 ************************************************************************************/
106inline bool_t page_is_flag( page_t   * page,
107                            uint32_t   value );
108
109/*************************************************************************************
110 * This function must be called by a thread running in the local cluster.
111 * It resets to 0 all bytes in a given page.
112 *************************************************************************************
113 * @ page     : pointer on page descriptor.
114 ************************************************************************************/
115void page_zero( page_t * page );
116
117/*************************************************************************************
118 * This function must be called by a thread running in the local cluster.
119 * It atomically increments the page refcount.
120 *************************************************************************************
121 * @ page     : pointer on page descriptor.
122 ************************************************************************************/
123inline void page_refcount_up( page_t * page );
124
125/*************************************************************************************
126 * This function must be called by a thread running in the local cluster.
127 * It atomically decrements the page refcount.
128 *************************************************************************************
129 * @ page     : pointer on page descriptor.
130 ************************************************************************************/
131inline void page_refcount_down( page_t * page );
132
133
134
135
136
137/*************************************************************************************
138 * This function must be called by a thread running in the local cluster.
139 * It initializes the page descriptor.
140 *************************************************************************************
141 * @ page_xp    : extended pointer to page descriptor.
142 ************************************************************************************/
143inline void page_remote_init( xptr_t  page_xp );
144
145/*************************************************************************************
146 * This function can be called by any thread running in any cluster.
147 * It atomically set one or several flags in a remote page descriptor
148 * identified by the <page_xp> argument.
149 *************************************************************************************
150 * @ page_xp : extended pointer to page descriptor.
151 * @ value   : all non zero bits in value will be set.
152 ************************************************************************************/
153inline void page_remote_set_flag( xptr_t    page_xp,
154                                  uint32_t  value );
155
156/*************************************************************************************
157 * This function can be called by any thread running in any cluster.
158 * It atomically reset one or several flags in a remote page descriptor
159 * identified by the <page_xp> argument.
160 *************************************************************************************
161 * @ page_xp : extended pointer to page descriptor.
162 * @ value   : all non zero bits in value will be cleared.
163 ************************************************************************************/
164inline void page_remote_clear_flag( xptr_t    page_xp,
165                                    uint32_t  value );
166
167/*************************************************************************************
168 * This function can be called by any thread running in any cluster.
169 * It tests the value of one or several flags in a remote page descriptor
170 * identified by the <page_xp> argument.
171 *************************************************************************************
172 * @ page_xp : extended pointer to page descriptor.
173 * @ value   : all non zero bits will be tested.
174 * @ returns true if at least one non zero bit in value is set / false otherwise.
175 ************************************************************************************/
176inline bool_t page_remote_is_flag( xptr_t    page_xp,
177                                   uint32_t  value );
178
179/*************************************************************************************
180 * This function can be called by any thread running in any cluster.
181 * It atomically increments the refcount for the remote page identified by
182 * the <page_xp> argument.
183 *************************************************************************************
184 * @ page_xp   : extended pointer on page descriptor.
185 ************************************************************************************/
186inline void page_remote_refcount_up( xptr_t page_xp );
187
188/*************************************************************************************
189 * This function can be called by any thread running in any cluster.
190 * It atomically decrements the refcount for the remote page identified by
191 * the <page_xp> argument.
192 *************************************************************************************
193 * @ page_xp   : extended pointer on page descriptor.
194 ************************************************************************************/
195inline void page_remote_refcount_down( xptr_t  page_xp );
196
197/*************************************************************************************
198 * This debug function can be called by any thread running in any cluster.
199 * It displays the values contained in a page descriptor.
200 *************************************************************************************
201 * @ page_xp     : extended pointer on page descriptor.
202 ************************************************************************************/
203void page_remote_display( xptr_t  page_xp );
204
205#endif  /* _PAGE_H_ */
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