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Linux kernel mirror (for testing)
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linux
1/*
2 * SPU file system -- system call stubs
3 *
4 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
5 * (C) Copyright 2006-2007, IBM Corporation
6 *
7 * Author: Arnd Bergmann <arndb@de.ibm.com>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2, or (at your option)
12 * any later version.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
22 */
23#include <linux/file.h>
24#include <linux/fs.h>
25#include <linux/module.h>
26#include <linux/syscalls.h>
27#include <linux/rcupdate.h>
28#include <linux/binfmts.h>
29
30#include <asm/spu.h>
31
32/* protected by rcu */
33static struct spufs_calls *spufs_calls;
34
35#ifdef CONFIG_SPU_FS_MODULE
36
37static inline struct spufs_calls *spufs_calls_get(void)
38{
39 struct spufs_calls *calls = NULL;
40
41 rcu_read_lock();
42 calls = rcu_dereference(spufs_calls);
43 if (calls && !try_module_get(calls->owner))
44 calls = NULL;
45 rcu_read_unlock();
46
47 return calls;
48}
49
50static inline void spufs_calls_put(struct spufs_calls *calls)
51{
52 BUG_ON(calls != spufs_calls);
53
54 /* we don't need to rcu this, as we hold a reference to the module */
55 module_put(spufs_calls->owner);
56}
57
58#else /* !defined CONFIG_SPU_FS_MODULE */
59
60static inline struct spufs_calls *spufs_calls_get(void)
61{
62 return spufs_calls;
63}
64
65static inline void spufs_calls_put(struct spufs_calls *calls) { }
66
67#endif /* CONFIG_SPU_FS_MODULE */
68
69SYSCALL_DEFINE4(spu_create, const char __user *, name, unsigned int, flags,
70 umode_t, mode, int, neighbor_fd)
71{
72 long ret;
73 struct spufs_calls *calls;
74
75 calls = spufs_calls_get();
76 if (!calls)
77 return -ENOSYS;
78
79 if (flags & SPU_CREATE_AFFINITY_SPU) {
80 struct fd neighbor = fdget(neighbor_fd);
81 ret = -EBADF;
82 if (neighbor.file) {
83 ret = calls->create_thread(name, flags, mode, neighbor.file);
84 fdput(neighbor);
85 }
86 } else
87 ret = calls->create_thread(name, flags, mode, NULL);
88
89 spufs_calls_put(calls);
90 return ret;
91}
92
93asmlinkage long sys_spu_run(int fd, __u32 __user *unpc, __u32 __user *ustatus)
94{
95 long ret;
96 struct fd arg;
97 struct spufs_calls *calls;
98
99 calls = spufs_calls_get();
100 if (!calls)
101 return -ENOSYS;
102
103 ret = -EBADF;
104 arg = fdget(fd);
105 if (arg.file) {
106 ret = calls->spu_run(arg.file, unpc, ustatus);
107 fdput(arg);
108 }
109
110 spufs_calls_put(calls);
111 return ret;
112}
113
114#ifdef CONFIG_COREDUMP
115int elf_coredump_extra_notes_size(void)
116{
117 struct spufs_calls *calls;
118 int ret;
119
120 calls = spufs_calls_get();
121 if (!calls)
122 return 0;
123
124 ret = calls->coredump_extra_notes_size();
125
126 spufs_calls_put(calls);
127
128 return ret;
129}
130
131int elf_coredump_extra_notes_write(struct coredump_params *cprm)
132{
133 struct spufs_calls *calls;
134 int ret;
135
136 calls = spufs_calls_get();
137 if (!calls)
138 return 0;
139
140 ret = calls->coredump_extra_notes_write(cprm);
141
142 spufs_calls_put(calls);
143
144 return ret;
145}
146#endif
147
148void notify_spus_active(void)
149{
150 struct spufs_calls *calls;
151
152 calls = spufs_calls_get();
153 if (!calls)
154 return;
155
156 calls->notify_spus_active();
157 spufs_calls_put(calls);
158
159 return;
160}
161
162int register_spu_syscalls(struct spufs_calls *calls)
163{
164 if (spufs_calls)
165 return -EBUSY;
166
167 rcu_assign_pointer(spufs_calls, calls);
168 return 0;
169}
170EXPORT_SYMBOL_GPL(register_spu_syscalls);
171
172void unregister_spu_syscalls(struct spufs_calls *calls)
173{
174 BUG_ON(spufs_calls->owner != calls->owner);
175 RCU_INIT_POINTER(spufs_calls, NULL);
176 synchronize_rcu();
177}
178EXPORT_SYMBOL_GPL(unregister_spu_syscalls);