1 #include <linux/file.h>
2 #include <linux/fs.h>
3 #include <linux/export.h>
4 #include <linux/mount.h>
5 #include <linux/namei.h>
6 #include <linux/slab.h>
7 
8 #include <linux/uaccess.h>
9 
10 #include "spufs.h"
11 
12 /**
13  * sys_spu_run - run code loaded into an SPU
14  *
15  * @unpc:    next program counter for the SPU
16  * @ustatus: status of the SPU
17  *
18  * This system call transfers the control of execution of a
19  * user space thread to an SPU. It will return when the
20  * SPU has finished executing or when it hits an error
21  * condition and it will be interrupted if a signal needs
22  * to be delivered to a handler in user space.
23  *
24  * The next program counter is set to the passed value
25  * before the SPU starts fetching code and the user space
26  * pointer gets updated with the new value when returning
27  * from kernel space.
28  *
29  * The status value returned from spu_run reflects the
30  * value of the spu_status register after the SPU has stopped.
31  *
32  */
33 static long do_spu_run(struct file *filp,
34 			__u32 __user *unpc,
35 			__u32 __user *ustatus)
36 {
37 	long ret;
38 	struct spufs_inode_info *i;
39 	u32 npc, status;
40 
41 	ret = -EFAULT;
42 	if (get_user(npc, unpc))
43 		goto out;
44 
45 	/* check if this file was created by spu_create */
46 	ret = -EINVAL;
47 	if (filp->f_op != &spufs_context_fops)
48 		goto out;
49 
50 	i = SPUFS_I(file_inode(filp));
51 	ret = spufs_run_spu(i->i_ctx, &npc, &status);
52 
53 	if (put_user(npc, unpc))
54 		ret = -EFAULT;
55 
56 	if (ustatus && put_user(status, ustatus))
57 		ret = -EFAULT;
58 out:
59 	return ret;
60 }
61 
62 static long do_spu_create(const char __user *pathname, unsigned int flags,
63 		umode_t mode, struct file *neighbor)
64 {
65 	struct path path;
66 	struct dentry *dentry;
67 	int ret;
68 
69 	dentry = user_path_create(AT_FDCWD, pathname, &path, LOOKUP_DIRECTORY);
70 	ret = PTR_ERR(dentry);
71 	if (!IS_ERR(dentry)) {
72 		ret = spufs_create(&path, dentry, flags, mode, neighbor);
73 		done_path_create(&path, dentry);
74 	}
75 
76 	return ret;
77 }
78 
79 struct spufs_calls spufs_calls = {
80 	.create_thread = do_spu_create,
81 	.spu_run = do_spu_run,
82 	.notify_spus_active = do_notify_spus_active,
83 	.owner = THIS_MODULE,
84 #ifdef CONFIG_COREDUMP
85 	.coredump_extra_notes_size = spufs_coredump_extra_notes_size,
86 	.coredump_extra_notes_write = spufs_coredump_extra_notes_write,
87 #endif
88 };
89