xref: /linux/arch/powerpc/platforms/cell/spu_syscalls.c (revision 1f2367a39f17bd553a75e179a747f9b257bc9478)
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 */
33 static struct spufs_calls *spufs_calls;
34 
35 #ifdef CONFIG_SPU_FS_MODULE
36 
37 static 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 
50 static 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 
60 static inline struct spufs_calls *spufs_calls_get(void)
61 {
62 	return spufs_calls;
63 }
64 
65 static inline void spufs_calls_put(struct spufs_calls *calls) { }
66 
67 #endif /* CONFIG_SPU_FS_MODULE */
68 
69 SYSCALL_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 
93 SYSCALL_DEFINE3(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
115 int 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 
131 int 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 
148 void 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 
162 int 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 }
170 EXPORT_SYMBOL_GPL(register_spu_syscalls);
171 
172 void 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 }
178 EXPORT_SYMBOL_GPL(unregister_spu_syscalls);
179