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);
179