1 /*
2  * Copyright (C) 2008-2009 Red Hat, Inc.  All rights reserved.
3  * Copyright 2010 Tilera Corporation. All Rights Reserved.
4  *
5  *   This program is free software; you can redistribute it and/or
6  *   modify it under the terms of the GNU General Public License
7  *   as published by the Free Software Foundation, version 2.
8  *
9  *   This program is distributed in the hope that it will be useful, but
10  *   WITHOUT ANY WARRANTY; without even the implied warranty of
11  *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
12  *   NON INFRINGEMENT.  See the GNU General Public License for
13  *   more details.
14  *
15  * See asm-generic/syscall.h for descriptions of what we must do here.
16  */
17 
18 #ifndef _ASM_TILE_SYSCALL_H
19 #define _ASM_TILE_SYSCALL_H
20 
21 #include <linux/sched.h>
22 #include <linux/err.h>
23 #include <linux/audit.h>
24 #include <linux/compat.h>
25 #include <arch/abi.h>
26 
27 /* The array of function pointers for syscalls. */
28 extern void *sys_call_table[];
29 #ifdef CONFIG_COMPAT
30 extern void *compat_sys_call_table[];
31 #endif
32 
33 /*
34  * Only the low 32 bits of orig_r0 are meaningful, so we return int.
35  * This importantly ignores the high bits on 64-bit, so comparisons
36  * sign-extend the low 32 bits.
37  */
syscall_get_nr(struct task_struct * t,struct pt_regs * regs)38 static inline int syscall_get_nr(struct task_struct *t, struct pt_regs *regs)
39 {
40 	return regs->regs[TREG_SYSCALL_NR];
41 }
42 
syscall_rollback(struct task_struct * task,struct pt_regs * regs)43 static inline void syscall_rollback(struct task_struct *task,
44 				    struct pt_regs *regs)
45 {
46 	regs->regs[0] = regs->orig_r0;
47 }
48 
syscall_get_error(struct task_struct * task,struct pt_regs * regs)49 static inline long syscall_get_error(struct task_struct *task,
50 				     struct pt_regs *regs)
51 {
52 	unsigned long error = regs->regs[0];
53 	return IS_ERR_VALUE(error) ? error : 0;
54 }
55 
syscall_get_return_value(struct task_struct * task,struct pt_regs * regs)56 static inline long syscall_get_return_value(struct task_struct *task,
57 					    struct pt_regs *regs)
58 {
59 	return regs->regs[0];
60 }
61 
syscall_set_return_value(struct task_struct * task,struct pt_regs * regs,int error,long val)62 static inline void syscall_set_return_value(struct task_struct *task,
63 					    struct pt_regs *regs,
64 					    int error, long val)
65 {
66 	if (error) {
67 		/* R0 is the passed-in negative error, R1 is positive. */
68 		regs->regs[0] = error;
69 		regs->regs[1] = -error;
70 	} else {
71 		/* R1 set to zero to indicate no error. */
72 		regs->regs[0] = val;
73 		regs->regs[1] = 0;
74 	}
75 }
76 
syscall_get_arguments(struct task_struct * task,struct pt_regs * regs,unsigned int i,unsigned int n,unsigned long * args)77 static inline void syscall_get_arguments(struct task_struct *task,
78 					 struct pt_regs *regs,
79 					 unsigned int i, unsigned int n,
80 					 unsigned long *args)
81 {
82 	BUG_ON(i + n > 6);
83 	memcpy(args, &regs[i], n * sizeof(args[0]));
84 }
85 
syscall_set_arguments(struct task_struct * task,struct pt_regs * regs,unsigned int i,unsigned int n,const unsigned long * args)86 static inline void syscall_set_arguments(struct task_struct *task,
87 					 struct pt_regs *regs,
88 					 unsigned int i, unsigned int n,
89 					 const unsigned long *args)
90 {
91 	BUG_ON(i + n > 6);
92 	memcpy(&regs[i], args, n * sizeof(args[0]));
93 }
94 
95 /*
96  * We don't care about endianness (__AUDIT_ARCH_LE bit) here because
97  * tile has the same system calls both on little- and big- endian.
98  */
syscall_get_arch(void)99 static inline int syscall_get_arch(void)
100 {
101 	if (is_compat_task())
102 		return AUDIT_ARCH_TILEGX32;
103 
104 #ifdef CONFIG_TILEGX
105 	return AUDIT_ARCH_TILEGX;
106 #else
107 	return AUDIT_ARCH_TILEPRO;
108 #endif
109 }
110 
111 #endif	/* _ASM_TILE_SYSCALL_H */
112