spu_syscalls.c 3.78 KB
Newer Older
1
2
3
4
/*
 * SPU file system -- system call stubs
 *
 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
5
 * (C) Copyright 2006-2007, IBM Corporation
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
 *
 * Author: Arnd Bergmann <arndb@de.ibm.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <linux/file.h>
24
#include <linux/fs.h>
25
26
#include <linux/module.h>
#include <linux/syscalls.h>
27
#include <linux/rcupdate.h>
28
29
30

#include <asm/spu.h>

31
32
/* protected by rcu */
static struct spufs_calls *spufs_calls;
33

34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
#ifdef CONFIG_SPU_FS_MODULE

static inline struct spufs_calls *spufs_calls_get(void)
{
	struct spufs_calls *calls = NULL;

	rcu_read_lock();
	calls = rcu_dereference(spufs_calls);
	if (calls && !try_module_get(calls->owner))
		calls = NULL;
	rcu_read_unlock();

	return calls;
}

static inline void spufs_calls_put(struct spufs_calls *calls)
{
	BUG_ON(calls != spufs_calls);

	/* we don't need to rcu this, as we hold a reference to the module */
	module_put(spufs_calls->owner);
}

#else /* !defined CONFIG_SPU_FS_MODULE */

static inline struct spufs_calls *spufs_calls_get(void)
{
	return spufs_calls;
}

static inline void spufs_calls_put(struct spufs_calls *calls) { }

#endif /* CONFIG_SPU_FS_MODULE */
67

68
69
SYSCALL_DEFINE4(spu_create, const char __user *, name, unsigned int, flags,
	umode_t, mode, int, neighbor_fd)
70
71
{
	long ret;
72
73
	struct file *neighbor;
	int fput_needed;
74
	struct spufs_calls *calls;
75

76
77
78
79
80
81
82
83
84
85
	calls = spufs_calls_get();
	if (!calls)
		return -ENOSYS;

	if (flags & SPU_CREATE_AFFINITY_SPU) {
		ret = -EBADF;
		neighbor = fget_light(neighbor_fd, &fput_needed);
		if (neighbor) {
			ret = calls->create_thread(name, flags, mode, neighbor);
			fput_light(neighbor, fput_needed);
86
		}
87
88
89
90
	} else
		ret = calls->create_thread(name, flags, mode, NULL);

	spufs_calls_put(calls);
91
92
93
94
95
96
97
98
	return ret;
}

asmlinkage long sys_spu_run(int fd, __u32 __user *unpc, __u32 __user *ustatus)
{
	long ret;
	struct file *filp;
	int fput_needed;
99
	struct spufs_calls *calls;
100

101
102
103
104
105
106
107
108
109
	calls = spufs_calls_get();
	if (!calls)
		return -ENOSYS;

	ret = -EBADF;
	filp = fget_light(fd, &fput_needed);
	if (filp) {
		ret = calls->spu_run(filp, unpc, ustatus);
		fput_light(filp, fput_needed);
110
	}
111
112

	spufs_calls_put(calls);
113
114
115
	return ret;
}

116
int elf_coredump_extra_notes_size(void)
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
{
	struct spufs_calls *calls;
	int ret;

	calls = spufs_calls_get();
	if (!calls)
		return 0;

	ret = calls->coredump_extra_notes_size();

	spufs_calls_put(calls);

	return ret;
}

132
int elf_coredump_extra_notes_write(struct file *file, loff_t *foffset)
133
134
{
	struct spufs_calls *calls;
135
	int ret;
136
137
138

	calls = spufs_calls_get();
	if (!calls)
139
		return 0;
140

141
	ret = calls->coredump_extra_notes_write(file, foffset);
142
143

	spufs_calls_put(calls);
144

145
	return ret;
146
147
}

148
149
150
151
152
153
154
155
156
157
158
159
160
161
void notify_spus_active(void)
{
	struct spufs_calls *calls;

	calls = spufs_calls_get();
	if (!calls)
		return;

	calls->notify_spus_active();
	spufs_calls_put(calls);

	return;
}

162
163
int register_spu_syscalls(struct spufs_calls *calls)
{
164
	if (spufs_calls)
165
166
		return -EBUSY;

167
	rcu_assign_pointer(spufs_calls, calls);
168
169
170
171
172
173
	return 0;
}
EXPORT_SYMBOL_GPL(register_spu_syscalls);

void unregister_spu_syscalls(struct spufs_calls *calls)
{
174
175
176
	BUG_ON(spufs_calls->owner != calls->owner);
	rcu_assign_pointer(spufs_calls, NULL);
	synchronize_rcu();
177
178
}
EXPORT_SYMBOL_GPL(unregister_spu_syscalls);