xref: /openbmc/linux/arch/powerpc/include/asm/syscall.h (revision 9ac8d3fb)
1 /*
2  * Access to user system call parameters and results
3  *
4  * Copyright (C) 2008 Red Hat, Inc.  All rights reserved.
5  *
6  * This copyrighted material is made available to anyone wishing to use,
7  * modify, copy, or redistribute it subject to the terms and conditions
8  * of the GNU General Public License v.2.
9  *
10  * See asm-generic/syscall.h for descriptions of what we must do here.
11  */
12 
13 #ifndef _ASM_SYSCALL_H
14 #define _ASM_SYSCALL_H	1
15 
16 #include <linux/sched.h>
17 
18 static inline long syscall_get_nr(struct task_struct *task,
19 				  struct pt_regs *regs)
20 {
21 	return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1L;
22 }
23 
24 static inline void syscall_rollback(struct task_struct *task,
25 				    struct pt_regs *regs)
26 {
27 	regs->gpr[3] = regs->orig_gpr3;
28 }
29 
30 static inline long syscall_get_error(struct task_struct *task,
31 				     struct pt_regs *regs)
32 {
33 	return (regs->ccr & 0x1000) ? -regs->gpr[3] : 0;
34 }
35 
36 static inline long syscall_get_return_value(struct task_struct *task,
37 					    struct pt_regs *regs)
38 {
39 	return regs->gpr[3];
40 }
41 
42 static inline void syscall_set_return_value(struct task_struct *task,
43 					    struct pt_regs *regs,
44 					    int error, long val)
45 {
46 	if (error) {
47 		regs->ccr |= 0x1000L;
48 		regs->gpr[3] = -error;
49 	} else {
50 		regs->ccr &= ~0x1000L;
51 		regs->gpr[3] = val;
52 	}
53 }
54 
55 static inline void syscall_get_arguments(struct task_struct *task,
56 					 struct pt_regs *regs,
57 					 unsigned int i, unsigned int n,
58 					 unsigned long *args)
59 {
60 	BUG_ON(i + n > 6);
61 #ifdef CONFIG_PPC64
62 	if (test_tsk_thread_flag(task, TIF_32BIT)) {
63 		/*
64 		 * Zero-extend 32-bit argument values.  The high bits are
65 		 * garbage ignored by the actual syscall dispatch.
66 		 */
67 		while (n-- > 0)
68 			args[n] = (u32) regs->gpr[3 + i + n];
69 		return;
70 	}
71 #endif
72 	memcpy(args, &regs->gpr[3 + i], n * sizeof(args[0]));
73 }
74 
75 static inline void syscall_set_arguments(struct task_struct *task,
76 					 struct pt_regs *regs,
77 					 unsigned int i, unsigned int n,
78 					 const unsigned long *args)
79 {
80 	BUG_ON(i + n > 6);
81 	memcpy(&regs->gpr[3 + i], args, n * sizeof(args[0]));
82 }
83 
84 #endif	/* _ASM_SYSCALL_H */
85