1 /* This file is part of the program psim.
3 Copyright (C) 1997,2008, Joel Sherrill <joel@OARcorp.com>
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.
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.
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.
25 #include "device_table.h"
43 sem - provide access to a unix semaphore
49 This device implements an interface to a unix semaphore.
55 reg = <address> <size> (required)
57 Determine where the memory lives in the parents address space.
59 key = <integer> (required)
61 This is the key of the unix semaphore.
66 Enable tracing of the sem:
68 | bash$ psim -t sem-device \
71 Configure a UNIX semaphore using key 0x12345678 mapped into psim
72 address space at 0xfff00000:
74 | -o '/sem@0xfff00000/reg 0xfff00000 0x80000' \
75 | -o '/sem@0xfff00000/key 0x12345678' \
77 sim/ppc/run -o '/#address-cells 1' \
78 -o '/sem@0xfff00000/reg 0xfff00000 12' \
79 -o '/sem@0xfff00000/key 0x12345678' ../psim-hello/hello
84 offset 4 - lock operation
85 offset 8 - unlock operation
87 All reads return the current or resulting count.
95 typedef struct _hw_sem_device
{
96 unsigned_word physical_address
;
106 struct semid_ds
*buf
;
107 unsigned short int *array
;
108 #if defined(__linux__)
109 struct seminfo
*__buf
;
115 hw_sem_init_data(device
*me
)
117 hw_sem_device
*sem
= (hw_sem_device
*)device_data(me
);
118 const device_unit
*d
;
122 /* initialize the properties of the sem */
124 if (device_find_property(me
, "key") == NULL
)
125 error("sem_init_data() required key property is missing\n");
127 if (device_find_property(me
, "value") == NULL
)
128 error("sem_init_data() required value property is missing\n");
130 sem
->key
= (key_t
) device_find_integer_property(me
, "key");
131 DTRACE(sem
, ("semaphore key (%d)\n", sem
->key
) );
133 sem
->initial
= (int) device_find_integer_property(me
, "value");
134 DTRACE(sem
, ("semaphore initial value (%d)\n", sem
->initial
) );
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
));
140 /* Now to initialize the semaphore */
142 if ( sem
->initial
!= -1 ) {
144 sem
->id
= semget(sem
->key
, 1, IPC_CREAT
| 0660);
146 error("hw_sem_init_data() semget failed\n");
148 help
.val
= sem
->initial
;
149 status
= semctl( sem
->id
, 0, SETVAL
, help
);
151 error("hw_sem_init_data() semctl -- set value failed\n");
154 sem
->id
= semget(sem
->key
, 1, 0660);
156 error("hw_sem_init_data() semget failed\n");
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
) );
166 hw_sem_attach_address_callback(device
*me
,
172 device
*client
) /*callback/default*/
174 hw_sem_device
*sem
= (hw_sem_device
*)device_data(me
);
177 error("sem_attach_address_callback() invalid address space\n");
180 error("sem_attach_address_callback() invalid size\n");
182 sem
->physical_address
= addr
;
183 DTRACE(sem
, ("semaphore physical_address=0x%x\n", addr
));
187 hw_sem_io_read_buffer(device
*me
,
195 hw_sem_device
*sem
= (hw_sem_device
*)device_data(me
);
201 /* do we need to worry about out of range addresses? */
203 DTRACE(sem
, ("semaphore read addr=0x%x length=%d\n", addr
, nr_bytes
));
205 if (!(addr
>= sem
->physical_address
&& addr
<= sem
->physical_address
+ 11))
206 error("hw_sem_io_read_buffer() invalid address - out of range\n");
209 error("hw_sem_io_read_buffer() invalid address - alignment\n");
212 error("hw_sem_io_read_buffer() invalid length\n");
214 switch ( (addr
- sem
->physical_address
) / 4 ) {
216 case 0: /* OBTAIN CURRENT VALUE */
224 status
= semop(sem
->id
, &sb
, 1);
226 perror( "hw_sem.c: lock" );
227 error("hw_sem_io_read_buffer() sem lock\n");
230 DTRACE(sem
, ("semaphore lock %d\n", sem
->count
));
238 status
= semop(sem
->id
, &sb
, 1);
240 perror( "hw_sem.c: unlock" );
241 error("hw_sem_io_read_buffer() sem unlock\n");
243 DTRACE(sem
, ("semaphore unlock %d\n", sem
->count
));
247 error("hw_sem_io_read_buffer() invalid address - unknown error\n");
251 /* assume target is big endian */
252 u32
= H2T_4(semctl( sem
->id
, 0, GETVAL
, help
));
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");
260 memcpy(dest
, &u32
, nr_bytes
);
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 */
270 { NULL
, }, /* interrupt */
271 { NULL
, }, /* unit */
276 hw_sem_create(const char *name
,
277 const device_unit
*unit_address
,
280 hw_sem_device
*sem
= ZALLOC(hw_sem_device
);
284 const device_descriptor hw_sem_device_descriptor
[] = {
285 { "sem", hw_sem_create
, &hw_sem_callbacks
},
289 #endif /* _HW_SEM_C_ */