1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * SPU file system -- system call stubs
4 *
5 * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
6 * (C) Copyright 2006-2007, IBM Corporation
7 *
8 * Author: Arnd Bergmann <arndb@de.ibm.com>
9 */
10 #include <linux/file.h>
11 #include <linux/fs.h>
12 #include <linux/module.h>
13 #include <linux/syscalls.h>
14 #include <linux/rcupdate.h>
15 #include <linux/binfmts.h>
16
17 #include <asm/spu.h>
18
19 /* protected by rcu */
20 static struct spufs_calls *spufs_calls;
21
22 #ifdef CONFIG_SPU_FS_MODULE
23
24 static inline struct spufs_calls *spufs_calls_get(void)
25 {
26 struct spufs_calls *calls = NULL;
27
28 rcu_read_lock();
29 calls = rcu_dereference(spufs_calls);
30 if (calls && !try_module_get(calls->owner))
31 calls = NULL;
32 rcu_read_unlock();
33
34 return calls;
35 }
36
37 static inline void spufs_calls_put(struct spufs_calls *calls)
38 {
39 BUG_ON(calls != spufs_calls);
40
41 /* we don't need to rcu this, as we hold a reference to the module */
42 module_put(spufs_calls->owner);
43 }
44
45 #else /* !defined CONFIG_SPU_FS_MODULE */
46
47 static inline struct spufs_calls *spufs_calls_get(void)
48 {
49 return spufs_calls;
50 }
51
52 static inline void spufs_calls_put(struct spufs_calls *calls) { }
53
54 #endif /* CONFIG_SPU_FS_MODULE */
55
56 SYSCALL_DEFINE4(spu_create, const char __user *, name, unsigned int, flags,
57 umode_t, mode, int, neighbor_fd)
58 {
59 long ret;
60 struct spufs_calls *calls;
61
62 calls = spufs_calls_get();
63 if (!calls)
64 return -ENOSYS;
65
66 if (flags & SPU_CREATE_AFFINITY_SPU) {
67 struct fd neighbor = fdget(neighbor_fd);
68 ret = -EBADF;
69 if (neighbor.file) {
70 ret = calls->create_thread(name, flags, mode, neighbor.file);
71 fdput(neighbor);
72 }
73 } else
74 ret = calls->create_thread(name, flags, mode, NULL);
75
76 spufs_calls_put(calls);
77 return ret;
78 }
79
80 SYSCALL_DEFINE3(spu_run,int, fd, __u32 __user *, unpc, __u32 __user *, ustatus)
81 {
82 long ret;
83 struct fd arg;
84 struct spufs_calls *calls;
85
86 calls = spufs_calls_get();
87 if (!calls)
88 return -ENOSYS;
89
90 ret = -EBADF;
91 arg = fdget(fd);
92 if (arg.file) {
93 ret = calls->spu_run(arg.file, unpc, ustatus);
94 fdput(arg);
95 }
96
97 spufs_calls_put(calls);
98 return ret;
99 }
100
101 #ifdef CONFIG_COREDUMP
102 int elf_coredump_extra_notes_size(void)
103 {
104 struct spufs_calls *calls;
105 int ret;
106
107 calls = spufs_calls_get();
108 if (!calls)
109 return 0;
110
111 ret = calls->coredump_extra_notes_size();
112
113 spufs_calls_put(calls);
114
115 return ret;
116 }
117
118 int elf_coredump_extra_notes_write(struct coredump_params *cprm)
119 {
120 struct spufs_calls *calls;
121 int ret;
122
123 calls = spufs_calls_get();
124 if (!calls)
125 return 0;
126
127 ret = calls->coredump_extra_notes_write(cprm);
128
129 spufs_calls_put(calls);
130
131 return ret;
132 }
133 #endif
134
135 void notify_spus_active(void)
136 {
137 struct spufs_calls *calls;
138
139 calls = spufs_calls_get();
140 if (!calls)
141 return;
142
143 calls->notify_spus_active();
144 spufs_calls_put(calls);
145
146 return;
147 }
148
149 int register_spu_syscalls(struct spufs_calls *calls)
150 {
151 if (spufs_calls)
152 return -EBUSY;
153
154 rcu_assign_pointer(spufs_calls, calls);
155 return 0;
156 }
157 EXPORT_SYMBOL_GPL(register_spu_syscalls);
158
159 void unregister_spu_syscalls(struct spufs_calls *calls)
160 {
161 BUG_ON(spufs_calls->owner != calls->owner);
162 RCU_INIT_POINTER(spufs_calls, NULL);
163 synchronize_rcu();
164 }
165 EXPORT_SYMBOL_GPL(unregister_spu_syscalls);
166
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