1 /*
2  * SPU file system -- system call stubs
3  *
4  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
5  *
6  * Author: Arnd Bergmann <arndb@de.ibm.com>
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License as published by
10  * the Free Software Foundation; either version 2, or (at your option)
11  * any later version.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
21  */
22 #include <linux/file.h>
23 #include <linux/module.h>
24 #include <linux/syscalls.h>
25 
26 #include <asm/spu.h>
27 
28 struct spufs_calls spufs_calls = {
29 	.owner = NULL,
30 };
31 
32 /* These stub syscalls are needed to have the actual implementation
33  * within a loadable module. When spufs is built into the kernel,
34  * this file is not used and the syscalls directly enter the fs code */
35 
36 asmlinkage long sys_spu_create(const char __user *name,
37 		unsigned int flags, mode_t mode, int neighbor_fd)
38 {
39 	long ret;
40 	struct module *owner = spufs_calls.owner;
41 	struct file *neighbor;
42 	int fput_needed;
43 
44 	ret = -ENOSYS;
45 	if (owner && try_module_get(owner)) {
46 		if (flags & SPU_CREATE_AFFINITY_SPU) {
47 			neighbor = fget_light(neighbor_fd, &fput_needed);
48 			if (neighbor) {
49 				ret = spufs_calls.create_thread(name, flags,
50 								mode, neighbor);
51 				fput_light(neighbor, fput_needed);
52 			}
53 		}
54 		else {
55 			ret = spufs_calls.create_thread(name, flags,
56 							mode, NULL);
57 		}
58 		module_put(owner);
59 	}
60 	return ret;
61 }
62 
63 asmlinkage long sys_spu_run(int fd, __u32 __user *unpc, __u32 __user *ustatus)
64 {
65 	long ret;
66 	struct file *filp;
67 	int fput_needed;
68 	struct module *owner = spufs_calls.owner;
69 
70 	ret = -ENOSYS;
71 	if (owner && try_module_get(owner)) {
72 		ret = -EBADF;
73 		filp = fget_light(fd, &fput_needed);
74 		if (filp) {
75 			ret = spufs_calls.spu_run(filp, unpc, ustatus);
76 			fput_light(filp, fput_needed);
77 		}
78 		module_put(owner);
79 	}
80 	return ret;
81 }
82 
83 int register_spu_syscalls(struct spufs_calls *calls)
84 {
85 	if (spufs_calls.owner)
86 		return -EBUSY;
87 
88 	spufs_calls.create_thread = calls->create_thread;
89 	spufs_calls.spu_run = calls->spu_run;
90 	smp_mb();
91 	spufs_calls.owner = calls->owner;
92 	return 0;
93 }
94 EXPORT_SYMBOL_GPL(register_spu_syscalls);
95 
96 void unregister_spu_syscalls(struct spufs_calls *calls)
97 {
98 	BUG_ON(spufs_calls.owner != calls->owner);
99 	spufs_calls.owner = NULL;
100 }
101 EXPORT_SYMBOL_GPL(unregister_spu_syscalls);
102