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1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * OpenRISC Linux
4 *
5 * Linux architectural port borrowing liberally from similar works of
6 * others. All original copyrights apply as per the original source
7 * declaration.
8 *
9 * OpenRISC implementation:
10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
12 * et al.
13 */
14#ifndef __ASM_OPENRISC_PTRACE_H
15#define __ASM_OPENRISC_PTRACE_H
16
17
18#include <asm/spr_defs.h>
19#include <uapi/asm/ptrace.h>
20#include <linux/compiler.h>
21
22/*
23 * Make kernel PTrace/register structures opaque to userspace... userspace can
24 * access thread state via the regset mechanism. This allows us a bit of
25 * flexibility in how we order the registers on the stack, permitting some
26 * optimizations like packing call-clobbered registers together so that
27 * they share a cacheline (not done yet, though... future optimization).
28 */
29
30#ifndef __ASSEMBLY__
31/*
32 * This struct describes how the registers are laid out on the kernel stack
33 * during a syscall or other kernel entry.
34 *
35 * This structure should always be cacheline aligned on the stack.
36 * FIXME: I don't think that's the case right now. The alignment is
37 * taken care of elsewhere... head.S, process.c, etc.
38 */
39
40struct pt_regs {
41 union {
42 struct {
43 /* Named registers */
44 long sr; /* Stored in place of r0 */
45 long sp; /* r1 */
46 long gpr2;
47 long gpr3;
48 long gpr4;
49 long gpr5;
50 long gpr6;
51 long gpr7;
52 long gpr8;
53 long gpr9;
54 long gpr10;
55 long gpr11;
56 long gpr12;
57 long gpr13;
58 long gpr14;
59 long gpr15;
60 long gpr16;
61 long gpr17;
62 long gpr18;
63 long gpr19;
64 long gpr20;
65 long gpr21;
66 long gpr22;
67 long gpr23;
68 long gpr24;
69 long gpr25;
70 long gpr26;
71 long gpr27;
72 long gpr28;
73 long gpr29;
74 long gpr30;
75 long gpr31;
76 };
77 struct {
78 /* Old style */
79 long offset[2];
80 long gprs[30];
81 };
82 struct {
83 /* New style */
84 long gpr[32];
85 };
86 };
87 long pc;
88 /* For restarting system calls:
89 * Set to syscall number for syscall exceptions,
90 * -1 for all other exceptions.
91 */
92 long orig_gpr11; /* For restarting system calls */
93 long dummy; /* Cheap alignment fix */
94 long dummy2; /* Cheap alignment fix */
95};
96
97/* TODO: Rename this to REDZONE because that's what it is */
98#define STACK_FRAME_OVERHEAD 128 /* size of minimum stack frame */
99
100#define MAX_REG_OFFSET offsetof(struct pt_regs, orig_gpr11)
101
102/* Helpers for working with the instruction pointer */
103static inline unsigned long instruction_pointer(struct pt_regs *regs)
104{
105 return (unsigned long)regs->pc;
106}
107static inline void instruction_pointer_set(struct pt_regs *regs,
108 unsigned long val)
109{
110 regs->pc = val;
111}
112
113#define user_mode(regs) (((regs)->sr & SPR_SR_SM) == 0)
114#define user_stack_pointer(regs) ((unsigned long)(regs)->sp)
115#define profile_pc(regs) instruction_pointer(regs)
116
117/* Valid only for Kernel mode traps. */
118static inline unsigned long kernel_stack_pointer(struct pt_regs *regs)
119{
120 return (unsigned long)regs->sp;
121}
122
123static inline long regs_return_value(struct pt_regs *regs)
124{
125 return regs->gpr[11];
126}
127
128extern int regs_query_register_offset(const char *name);
129extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs,
130 unsigned int n);
131
132/**
133 * regs_get_register() - get register value from its offset
134 * @regs: pt_regs from which register value is gotten
135 * @offset: offset of the register.
136 *
137 * regs_get_register returns the value of a register whose offset from @regs.
138 * The @offset is the offset of the register in struct pt_regs.
139 * If @offset is bigger than MAX_REG_OFFSET, this returns 0.
140 */
141static inline unsigned long regs_get_register(struct pt_regs *regs,
142 unsigned int offset)
143{
144 if (unlikely(offset > MAX_REG_OFFSET))
145 return 0;
146
147 return *(unsigned long *)((unsigned long)regs + offset);
148}
149
150#endif /* __ASSEMBLY__ */
151
152/*
153 * Offsets used by 'ptrace' system call interface.
154 */
155#define PT_SR 0
156#define PT_SP 4
157#define PT_GPR2 8
158#define PT_GPR3 12
159#define PT_GPR4 16
160#define PT_GPR5 20
161#define PT_GPR6 24
162#define PT_GPR7 28
163#define PT_GPR8 32
164#define PT_GPR9 36
165#define PT_GPR10 40
166#define PT_GPR11 44
167#define PT_GPR12 48
168#define PT_GPR13 52
169#define PT_GPR14 56
170#define PT_GPR15 60
171#define PT_GPR16 64
172#define PT_GPR17 68
173#define PT_GPR18 72
174#define PT_GPR19 76
175#define PT_GPR20 80
176#define PT_GPR21 84
177#define PT_GPR22 88
178#define PT_GPR23 92
179#define PT_GPR24 96
180#define PT_GPR25 100
181#define PT_GPR26 104
182#define PT_GPR27 108
183#define PT_GPR28 112
184#define PT_GPR29 116
185#define PT_GPR30 120
186#define PT_GPR31 124
187#define PT_PC 128
188#define PT_ORIG_GPR11 132
189
190#endif /* __ASM_OPENRISC_PTRACE_H */