xref: /openbmc/linux/arch/powerpc/include/asm/syscall.h (revision 3c6a73cc)
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 <uapi/linux/audit.h>
17 #include <linux/sched.h>
18 #include <linux/thread_info.h>
19 
20 /* ftrace syscalls requires exporting the sys_call_table */
21 #ifdef CONFIG_FTRACE_SYSCALLS
22 extern const unsigned long *sys_call_table;
23 #endif /* CONFIG_FTRACE_SYSCALLS */
24 
25 static inline long syscall_get_nr(struct task_struct *task,
26 				  struct pt_regs *regs)
27 {
28 	return TRAP(regs) == 0xc00 ? regs->gpr[0] : -1L;
29 }
30 
31 static inline void syscall_rollback(struct task_struct *task,
32 				    struct pt_regs *regs)
33 {
34 	regs->gpr[3] = regs->orig_gpr3;
35 }
36 
37 static inline long syscall_get_error(struct task_struct *task,
38 				     struct pt_regs *regs)
39 {
40 	return (regs->ccr & 0x10000000) ? -regs->gpr[3] : 0;
41 }
42 
43 static inline long syscall_get_return_value(struct task_struct *task,
44 					    struct pt_regs *regs)
45 {
46 	return regs->gpr[3];
47 }
48 
49 static inline void syscall_set_return_value(struct task_struct *task,
50 					    struct pt_regs *regs,
51 					    int error, long val)
52 {
53 	if (error) {
54 		regs->ccr |= 0x10000000L;
55 		regs->gpr[3] = -error;
56 	} else {
57 		regs->ccr &= ~0x10000000L;
58 		regs->gpr[3] = val;
59 	}
60 }
61 
62 static inline void syscall_get_arguments(struct task_struct *task,
63 					 struct pt_regs *regs,
64 					 unsigned int i, unsigned int n,
65 					 unsigned long *args)
66 {
67 	BUG_ON(i + n > 6);
68 #ifdef CONFIG_PPC64
69 	if (test_tsk_thread_flag(task, TIF_32BIT)) {
70 		/*
71 		 * Zero-extend 32-bit argument values.  The high bits are
72 		 * garbage ignored by the actual syscall dispatch.
73 		 */
74 		while (n-- > 0)
75 			args[n] = (u32) regs->gpr[3 + i + n];
76 		return;
77 	}
78 #endif
79 	memcpy(args, &regs->gpr[3 + i], n * sizeof(args[0]));
80 }
81 
82 static inline void syscall_set_arguments(struct task_struct *task,
83 					 struct pt_regs *regs,
84 					 unsigned int i, unsigned int n,
85 					 const unsigned long *args)
86 {
87 	BUG_ON(i + n > 6);
88 	memcpy(&regs->gpr[3 + i], args, n * sizeof(args[0]));
89 }
90 
91 static inline int syscall_get_arch(void)
92 {
93 	return is_32bit_task() ? AUDIT_ARCH_PPC : AUDIT_ARCH_PPC64;
94 }
95 #endif	/* _ASM_SYSCALL_H */
96