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00a0b122 JS |
1 | /* This file is part of the program psim. |
2 | ||
3 | Copyright (C) 1997,2008, Joel Sherrill <joel@OARcorp.com> | |
4 | ||
5 | This program is free software; you can redistribute it and/or modify | |
6 | it under the terms of the GNU General Public License as published by | |
7 | the Free Software Foundation; either version 2 of the License, or | |
8 | (at your option) any later version. | |
9 | ||
10 | This program is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
13 | GNU General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU General Public License | |
16 | along with this program; if not, write to the Free Software | |
17 | Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
18 | ||
19 | */ | |
20 | ||
21 | ||
22 | #ifndef _HW_SEM_C_ | |
23 | #define _HW_SEM_C_ | |
24 | ||
25 | #include "device_table.h" | |
26 | ||
27 | #ifdef HAVE_STRING_H | |
28 | #include <string.h> | |
29 | #else | |
30 | #ifdef HAVE_STRINGS_H | |
31 | #include <strings.h> | |
32 | #endif | |
33 | #endif | |
34 | ||
35 | #include <sys/ipc.h> | |
36 | #include <sys/sem.h> | |
37 | ||
38 | #include <errno.h> | |
39 | ||
40 | /* DEVICE | |
41 | ||
42 | ||
43 | sem - provide access to a unix semaphore | |
44 | ||
45 | ||
46 | DESCRIPTION | |
47 | ||
48 | ||
49 | This device implements an interface to a unix semaphore. | |
50 | ||
51 | ||
52 | PROPERTIES | |
53 | ||
54 | ||
55 | reg = <address> <size> (required) | |
56 | ||
57 | Determine where the memory lives in the parents address space. | |
58 | ||
59 | key = <integer> (required) | |
60 | ||
61 | This is the key of the unix semaphore. | |
62 | ||
63 | EXAMPLES | |
64 | ||
65 | ||
66 | Enable tracing of the sem: | |
67 | ||
68 | | bash$ psim -t sem-device \ | |
69 | ||
70 | ||
71 | Configure a UNIX semaphore using key 0x12345678 mapped into psim | |
72 | address space at 0xfff00000: | |
73 | ||
74 | | -o '/sem@0xfff00000/reg 0xfff00000 0x80000' \ | |
75 | | -o '/sem@0xfff00000/key 0x12345678' \ | |
76 | ||
77 | sim/ppc/run -o '/#address-cells 1' \ | |
78 | -o '/sem@0xfff00000/reg 0xfff00000 12' \ | |
79 | -o '/sem@0xfff00000/key 0x12345678' ../psim-hello/hello | |
80 | ||
81 | REGISTERS | |
82 | ||
83 | offset 0 - lock count | |
84 | offset 4 - lock operation | |
85 | offset 8 - unlock operation | |
86 | ||
87 | All reads return the current or resulting count. | |
88 | ||
89 | BUGS | |
90 | ||
91 | None known. | |
92 | ||
93 | */ | |
94 | ||
95 | typedef struct _hw_sem_device { | |
96 | unsigned_word physical_address; | |
97 | key_t key; | |
98 | int id; | |
99 | int initial; | |
100 | int count; | |
101 | } hw_sem_device; | |
102 | ||
bf0275b1 | 103 | #ifndef HAVE_UNION_SEMUN |
00a0b122 JS |
104 | union semun { |
105 | int val; | |
106 | struct semid_ds *buf; | |
107 | unsigned short int *array; | |
108 | #if defined(__linux__) | |
109 | struct seminfo *__buf; | |
110 | #endif | |
111 | }; | |
112 | #endif | |
113 | ||
114 | static void | |
115 | hw_sem_init_data(device *me) | |
116 | { | |
117 | hw_sem_device *sem = (hw_sem_device*)device_data(me); | |
118 | const device_unit *d; | |
119 | int status; | |
120 | union semun help; | |
121 | ||
122 | /* initialize the properties of the sem */ | |
123 | ||
124 | if (device_find_property(me, "key") == NULL) | |
125 | error("sem_init_data() required key property is missing\n"); | |
126 | ||
127 | if (device_find_property(me, "value") == NULL) | |
128 | error("sem_init_data() required value property is missing\n"); | |
129 | ||
130 | sem->key = (key_t) device_find_integer_property(me, "key"); | |
131 | DTRACE(sem, ("semaphore key (%d)\n", sem->key) ); | |
132 | ||
133 | sem->initial = (int) device_find_integer_property(me, "value"); | |
134 | DTRACE(sem, ("semaphore initial value (%d)\n", sem->initial) ); | |
135 | ||
136 | d = device_unit_address(me); | |
137 | sem->physical_address = d->cells[ d->nr_cells-1 ]; | |
138 | DTRACE(sem, ("semaphore physical_address=0x%x\n", sem->physical_address)); | |
139 | ||
140 | /* Now to initialize the semaphore */ | |
141 | ||
142 | if ( sem->initial != -1 ) { | |
143 | ||
144 | sem->id = semget(sem->key, 1, IPC_CREAT | 0660); | |
145 | if (sem->id == -1) | |
146 | error("hw_sem_init_data() semget failed\n"); | |
147 | ||
148 | help.val = sem->initial; | |
149 | status = semctl( sem->id, 0, SETVAL, help ); | |
150 | if (status == -1) | |
151 | error("hw_sem_init_data() semctl -- set value failed\n"); | |
152 | ||
153 | } else { | |
154 | sem->id = semget(sem->key, 1, 0660); | |
155 | if (sem->id == -1) | |
156 | error("hw_sem_init_data() semget failed\n"); | |
157 | } | |
158 | ||
159 | sem->count = semctl( sem->id, 0, GETVAL, help ); | |
160 | if (sem->count == -1) | |
161 | error("hw_sem_init_data() semctl -- get value failed\n"); | |
162 | DTRACE(sem, ("semaphore OS value (%d)\n", sem->count) ); | |
163 | } | |
164 | ||
165 | static void | |
166 | hw_sem_attach_address_callback(device *me, | |
167 | attach_type attach, | |
168 | int space, | |
169 | unsigned_word addr, | |
170 | unsigned nr_bytes, | |
171 | access_type access, | |
172 | device *client) /*callback/default*/ | |
173 | { | |
174 | hw_sem_device *sem = (hw_sem_device*)device_data(me); | |
175 | ||
176 | if (space != 0) | |
177 | error("sem_attach_address_callback() invalid address space\n"); | |
178 | ||
179 | if (nr_bytes == 12) | |
180 | error("sem_attach_address_callback() invalid size\n"); | |
181 | ||
182 | sem->physical_address = addr; | |
183 | DTRACE(sem, ("semaphore physical_address=0x%x\n", addr)); | |
184 | } | |
185 | ||
186 | static unsigned | |
187 | hw_sem_io_read_buffer(device *me, | |
188 | void *dest, | |
189 | int space, | |
190 | unsigned_word addr, | |
191 | unsigned nr_bytes, | |
192 | cpu *processor, | |
193 | unsigned_word cia) | |
194 | { | |
195 | hw_sem_device *sem = (hw_sem_device*)device_data(me); | |
196 | struct sembuf sb; | |
197 | int status; | |
198 | unsigned32 u32; | |
199 | union semun help; | |
200 | ||
201 | /* do we need to worry about out of range addresses? */ | |
202 | ||
203 | DTRACE(sem, ("semaphore read addr=0x%x length=%d\n", addr, nr_bytes)); | |
204 | ||
205 | if (!(addr >= sem->physical_address && addr <= sem->physical_address + 11)) | |
206 | error("hw_sem_io_read_buffer() invalid address - out of range\n"); | |
207 | ||
208 | if ((addr % 4) != 0) | |
209 | error("hw_sem_io_read_buffer() invalid address - alignment\n"); | |
210 | ||
211 | if (nr_bytes != 4) | |
212 | error("hw_sem_io_read_buffer() invalid length\n"); | |
213 | ||
214 | switch ( (addr - sem->physical_address) / 4 ) { | |
215 | ||
216 | case 0: /* OBTAIN CURRENT VALUE */ | |
217 | break; | |
218 | ||
219 | case 1: /* LOCK */ | |
220 | sb.sem_num = 0; | |
221 | sb.sem_op = -1; | |
222 | sb.sem_flg = 0; | |
223 | ||
224 | status = semop(sem->id, &sb, 1); | |
225 | if (status == -1) { | |
226 | perror( "hw_sem.c: lock" ); | |
227 | error("hw_sem_io_read_buffer() sem lock\n"); | |
228 | } | |
229 | ||
230 | DTRACE(sem, ("semaphore lock %d\n", sem->count)); | |
231 | break; | |
232 | ||
233 | case 2: /* UNLOCK */ | |
234 | sb.sem_num = 0; | |
235 | sb.sem_op = 1; | |
236 | sb.sem_flg = 0; | |
237 | ||
238 | status = semop(sem->id, &sb, 1); | |
239 | if (status == -1) { | |
240 | perror( "hw_sem.c: unlock" ); | |
241 | error("hw_sem_io_read_buffer() sem unlock\n"); | |
242 | } | |
243 | DTRACE(sem, ("semaphore unlock %d\n", sem->count)); | |
244 | break; | |
245 | ||
246 | default: | |
247 | error("hw_sem_io_read_buffer() invalid address - unknown error\n"); | |
248 | break; | |
249 | } | |
250 | ||
251 | /* assume target is big endian */ | |
252 | u32 = H2T_4(semctl( sem->id, 0, GETVAL, help )); | |
253 | ||
254 | DTRACE(sem, ("semaphore OS value (%d)\n", u32) ); | |
255 | if (u32 == 0xffffffff) { | |
256 | perror( "hw_sem.c: getval" ); | |
257 | error("hw_sem_io_read_buffer() semctl -- get value failed\n"); | |
258 | } | |
259 | ||
260 | memcpy(dest, &u32, nr_bytes); | |
261 | return nr_bytes; | |
262 | ||
263 | } | |
264 | ||
265 | static device_callbacks const hw_sem_callbacks = { | |
266 | { generic_device_init_address, hw_sem_init_data }, | |
267 | { hw_sem_attach_address_callback, }, /* address */ | |
268 | { hw_sem_io_read_buffer, NULL }, /* IO */ | |
269 | { NULL, }, /* DMA */ | |
270 | { NULL, }, /* interrupt */ | |
271 | { NULL, }, /* unit */ | |
272 | NULL, | |
273 | }; | |
274 | ||
275 | static void * | |
276 | hw_sem_create(const char *name, | |
277 | const device_unit *unit_address, | |
278 | const char *args) | |
279 | { | |
280 | hw_sem_device *sem = ZALLOC(hw_sem_device); | |
281 | return sem; | |
282 | } | |
283 | ||
284 | const device_descriptor hw_sem_device_descriptor[] = { | |
285 | { "sem", hw_sem_create, &hw_sem_callbacks }, | |
286 | { NULL }, | |
287 | }; | |
288 | ||
289 | #endif /* _HW_SEM_C_ */ |