1/*
2 * OpenRISC Linux
3 *
4 * Linux architectural port borrowing liberally from similar works of
5 * others.  All original copyrights apply as per the original source
6 * declaration.
7 *
8 * OpenRISC implementation:
9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
11 * et al.
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 */
18#ifndef __ASM_OPENRISC_PTRACE_H
19#define __ASM_OPENRISC_PTRACE_H
20
21
22#include <asm/spr_defs.h>
23#include <uapi/asm/ptrace.h>
24
25/*
26 * Make kernel PTrace/register structures opaque to userspace... userspace can
27 * access thread state via the regset mechanism.  This allows us a bit of
28 * flexibility in how we order the registers on the stack, permitting some
29 * optimizations like packing call-clobbered registers together so that
30 * they share a cacheline (not done yet, though... future optimization).
31 */
32
33#ifndef __ASSEMBLY__
34/*
35 * This struct describes how the registers are laid out on the kernel stack
36 * during a syscall or other kernel entry.
37 *
38 * This structure should always be cacheline aligned on the stack.
39 * FIXME: I don't think that's the case right now.  The alignment is
40 * taken care of elsewhere... head.S, process.c, etc.
41 */
42
43struct pt_regs {
44	union {
45		struct {
46			/* Named registers */
47			long  sr;	/* Stored in place of r0 */
48			long  sp;	/* r1 */
49		};
50		struct {
51			/* Old style */
52			long offset[2];
53			long gprs[30];
54		};
55		struct {
56			/* New style */
57			long gpr[32];
58		};
59	};
60	long  pc;
61	/* For restarting system calls:
62	 * Set to syscall number for syscall exceptions,
63	 * -1 for all other exceptions.
64	 */
65	long  orig_gpr11;	/* For restarting system calls */
66	long dummy;		/* Cheap alignment fix */
67	long dummy2;		/* Cheap alignment fix */
68};
69
70/* TODO: Rename this to REDZONE because that's what it is */
71#define STACK_FRAME_OVERHEAD  128  /* size of minimum stack frame */
72
73#define instruction_pointer(regs)	((regs)->pc)
74#define user_mode(regs)			(((regs)->sr & SPR_SR_SM) == 0)
75#define user_stack_pointer(regs)	((unsigned long)(regs)->sp)
76#define profile_pc(regs)		instruction_pointer(regs)
77
78static inline long regs_return_value(struct pt_regs *regs)
79{
80	return regs->gpr[11];
81}
82
83#endif /* __ASSEMBLY__ */
84
85/*
86 * Offsets used by 'ptrace' system call interface.
87 */
88#define PT_SR         0
89#define PT_SP         4
90#define PT_GPR2       8
91#define PT_GPR3       12
92#define PT_GPR4       16
93#define PT_GPR5       20
94#define PT_GPR6       24
95#define PT_GPR7       28
96#define PT_GPR8       32
97#define PT_GPR9       36
98#define PT_GPR10      40
99#define PT_GPR11      44
100#define PT_GPR12      48
101#define PT_GPR13      52
102#define PT_GPR14      56
103#define PT_GPR15      60
104#define PT_GPR16      64
105#define PT_GPR17      68
106#define PT_GPR18      72
107#define PT_GPR19      76
108#define PT_GPR20      80
109#define PT_GPR21      84
110#define PT_GPR22      88
111#define PT_GPR23      92
112#define PT_GPR24      96
113#define PT_GPR25      100
114#define PT_GPR26      104
115#define PT_GPR27      108
116#define PT_GPR28      112
117#define PT_GPR29      116
118#define PT_GPR30      120
119#define PT_GPR31      124
120#define PT_PC	      128
121#define PT_ORIG_GPR11 132
122#define PT_SYSCALLNO  136
123
124#endif /* __ASM_OPENRISC_PTRACE_H */
125