289 lines
6.7 KiB
C
289 lines
6.7 KiB
C
/* This file is part of the program psim.
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Copyright (C) 1997,2008, Joel Sherrill <joel@OARcorp.com>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#ifndef _HW_SEM_C_
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#define _HW_SEM_C_
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#include "device_table.h"
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#ifdef HAVE_STRING_H
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#include <string.h>
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#else
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#ifdef HAVE_STRINGS_H
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#include <strings.h>
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#endif
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#endif
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#include <sys/ipc.h>
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#include <sys/sem.h>
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#include <errno.h>
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/* DEVICE
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sem - provide access to a unix semaphore
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DESCRIPTION
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This device implements an interface to a unix semaphore.
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PROPERTIES
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reg = <address> <size> (required)
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Determine where the memory lives in the parents address space.
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key = <integer> (required)
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This is the key of the unix semaphore.
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EXAMPLES
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Enable tracing of the sem:
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| bash$ psim -t sem-device \
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Configure a UNIX semaphore using key 0x12345678 mapped into psim
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address space at 0xfff00000:
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| -o '/sem@0xfff00000/reg 0xfff00000 0x80000' \
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| -o '/sem@0xfff00000/key 0x12345678' \
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sim/ppc/run -o '/#address-cells 1' \
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-o '/sem@0xfff00000/reg 0xfff00000 12' \
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-o '/sem@0xfff00000/key 0x12345678' ../psim-hello/hello
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REGISTERS
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offset 0 - lock count
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offset 4 - lock operation
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offset 8 - unlock operation
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All reads return the current or resulting count.
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BUGS
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None known.
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*/
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typedef struct _hw_sem_device {
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unsigned_word physical_address;
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key_t key;
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int id;
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int initial;
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int count;
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} hw_sem_device;
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#ifndef HAVE_UNION_SEMUN
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union semun {
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int val;
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struct semid_ds *buf;
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unsigned short int *array;
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#if defined(__linux__)
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struct seminfo *__buf;
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#endif
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};
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#endif
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static void
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hw_sem_init_data(device *me)
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{
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hw_sem_device *sem = (hw_sem_device*)device_data(me);
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const device_unit *d;
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int status;
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union semun help;
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/* initialize the properties of the sem */
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if (device_find_property(me, "key") == NULL)
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error("sem_init_data() required key property is missing\n");
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if (device_find_property(me, "value") == NULL)
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error("sem_init_data() required value property is missing\n");
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sem->key = (key_t) device_find_integer_property(me, "key");
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DTRACE(sem, ("semaphore key (%d)\n", sem->key) );
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sem->initial = (int) device_find_integer_property(me, "value");
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DTRACE(sem, ("semaphore initial value (%d)\n", sem->initial) );
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d = device_unit_address(me);
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sem->physical_address = d->cells[ d->nr_cells-1 ];
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DTRACE(sem, ("semaphore physical_address=0x%x\n", sem->physical_address));
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/* Now to initialize the semaphore */
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if ( sem->initial != -1 ) {
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sem->id = semget(sem->key, 1, IPC_CREAT | 0660);
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if (sem->id == -1)
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error("hw_sem_init_data() semget failed\n");
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help.val = sem->initial;
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status = semctl( sem->id, 0, SETVAL, help );
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if (status == -1)
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error("hw_sem_init_data() semctl -- set value failed\n");
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} else {
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sem->id = semget(sem->key, 1, 0660);
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if (sem->id == -1)
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error("hw_sem_init_data() semget failed\n");
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}
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sem->count = semctl( sem->id, 0, GETVAL, help );
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if (sem->count == -1)
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error("hw_sem_init_data() semctl -- get value failed\n");
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DTRACE(sem, ("semaphore OS value (%d)\n", sem->count) );
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}
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static void
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hw_sem_attach_address_callback(device *me,
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attach_type attach,
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int space,
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unsigned_word addr,
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unsigned nr_bytes,
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access_type access,
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device *client) /*callback/default*/
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{
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hw_sem_device *sem = (hw_sem_device*)device_data(me);
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if (space != 0)
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error("sem_attach_address_callback() invalid address space\n");
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if (nr_bytes == 12)
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error("sem_attach_address_callback() invalid size\n");
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sem->physical_address = addr;
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DTRACE(sem, ("semaphore physical_address=0x%x\n", addr));
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}
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static unsigned
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hw_sem_io_read_buffer(device *me,
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void *dest,
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int space,
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unsigned_word addr,
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unsigned nr_bytes,
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cpu *processor,
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unsigned_word cia)
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{
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hw_sem_device *sem = (hw_sem_device*)device_data(me);
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struct sembuf sb;
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int status;
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unsigned32 u32;
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union semun help;
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/* do we need to worry about out of range addresses? */
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DTRACE(sem, ("semaphore read addr=0x%x length=%d\n", addr, nr_bytes));
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if (!(addr >= sem->physical_address && addr <= sem->physical_address + 11))
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error("hw_sem_io_read_buffer() invalid address - out of range\n");
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if ((addr % 4) != 0)
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error("hw_sem_io_read_buffer() invalid address - alignment\n");
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if (nr_bytes != 4)
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error("hw_sem_io_read_buffer() invalid length\n");
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switch ( (addr - sem->physical_address) / 4 ) {
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case 0: /* OBTAIN CURRENT VALUE */
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break;
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case 1: /* LOCK */
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sb.sem_num = 0;
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sb.sem_op = -1;
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sb.sem_flg = 0;
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status = semop(sem->id, &sb, 1);
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if (status == -1) {
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perror( "hw_sem.c: lock" );
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error("hw_sem_io_read_buffer() sem lock\n");
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}
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DTRACE(sem, ("semaphore lock %d\n", sem->count));
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break;
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case 2: /* UNLOCK */
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sb.sem_num = 0;
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sb.sem_op = 1;
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sb.sem_flg = 0;
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status = semop(sem->id, &sb, 1);
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if (status == -1) {
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perror( "hw_sem.c: unlock" );
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error("hw_sem_io_read_buffer() sem unlock\n");
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}
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DTRACE(sem, ("semaphore unlock %d\n", sem->count));
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break;
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default:
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error("hw_sem_io_read_buffer() invalid address - unknown error\n");
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break;
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}
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/* assume target is big endian */
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u32 = H2T_4(semctl( sem->id, 0, GETVAL, help ));
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DTRACE(sem, ("semaphore OS value (%d)\n", u32) );
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if (u32 == 0xffffffff) {
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perror( "hw_sem.c: getval" );
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error("hw_sem_io_read_buffer() semctl -- get value failed\n");
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}
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memcpy(dest, &u32, nr_bytes);
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return nr_bytes;
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}
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static device_callbacks const hw_sem_callbacks = {
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{ generic_device_init_address, hw_sem_init_data },
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{ hw_sem_attach_address_callback, }, /* address */
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{ hw_sem_io_read_buffer, NULL }, /* IO */
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{ NULL, }, /* DMA */
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{ NULL, }, /* interrupt */
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{ NULL, }, /* unit */
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NULL,
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};
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static void *
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hw_sem_create(const char *name,
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const device_unit *unit_address,
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const char *args)
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{
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hw_sem_device *sem = ZALLOC(hw_sem_device);
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return sem;
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}
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const device_descriptor hw_sem_device_descriptor[] = {
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{ "sem", hw_sem_create, &hw_sem_callbacks },
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{ NULL },
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};
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#endif /* _HW_SEM_C_ */
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