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 
21 /*
22  * Make kernel PTrace/register structures opaque to userspace... userspace can
23  * access thread state via the regset mechanism.  This allows us a bit of
24  * flexibility in how we order the registers on the stack, permitting some
25  * optimizations like packing call-clobbered registers together so that
26  * they share a cacheline (not done yet, though... future optimization).
27  */
28 
29 #ifndef __ASSEMBLY__
30 /*
31  * This struct describes how the registers are laid out on the kernel stack
32  * during a syscall or other kernel entry.
33  *
34  * This structure should always be cacheline aligned on the stack.
35  * FIXME: I don't think that's the case right now.  The alignment is
36  * taken care of elsewhere... head.S, process.c, etc.
37  */
38 
39 struct pt_regs {
40 	union {
41 		struct {
42 			/* Named registers */
43 			long  sr;	/* Stored in place of r0 */
44 			long  sp;	/* r1 */
45 		};
46 		struct {
47 			/* Old style */
48 			long offset[2];
49 			long gprs[30];
50 		};
51 		struct {
52 			/* New style */
53 			long gpr[32];
54 		};
55 	};
56 	long  pc;
57 	/* For restarting system calls:
58 	 * Set to syscall number for syscall exceptions,
59 	 * -1 for all other exceptions.
60 	 */
61 	long  orig_gpr11;	/* For restarting system calls */
62 	long fpcsr;		/* Floating point control status register. */
63 	long dummy2;		/* Cheap alignment fix */
64 };
65 
66 /* TODO: Rename this to REDZONE because that's what it is */
67 #define STACK_FRAME_OVERHEAD  128  /* size of minimum stack frame */
68 
69 #define instruction_pointer(regs)	((regs)->pc)
70 #define user_mode(regs)			(((regs)->sr & SPR_SR_SM) == 0)
71 #define user_stack_pointer(regs)	((unsigned long)(regs)->sp)
72 #define profile_pc(regs)		instruction_pointer(regs)
73 
regs_return_value(struct pt_regs * regs)74 static inline long regs_return_value(struct pt_regs *regs)
75 {
76 	return regs->gpr[11];
77 }
78 
79 #endif /* __ASSEMBLY__ */
80 
81 /*
82  * Offsets used by 'ptrace' system call interface.
83  */
84 #define PT_SR         0
85 #define PT_SP         4
86 #define PT_GPR2       8
87 #define PT_GPR3       12
88 #define PT_GPR4       16
89 #define PT_GPR5       20
90 #define PT_GPR6       24
91 #define PT_GPR7       28
92 #define PT_GPR8       32
93 #define PT_GPR9       36
94 #define PT_GPR10      40
95 #define PT_GPR11      44
96 #define PT_GPR12      48
97 #define PT_GPR13      52
98 #define PT_GPR14      56
99 #define PT_GPR15      60
100 #define PT_GPR16      64
101 #define PT_GPR17      68
102 #define PT_GPR18      72
103 #define PT_GPR19      76
104 #define PT_GPR20      80
105 #define PT_GPR21      84
106 #define PT_GPR22      88
107 #define PT_GPR23      92
108 #define PT_GPR24      96
109 #define PT_GPR25      100
110 #define PT_GPR26      104
111 #define PT_GPR27      108
112 #define PT_GPR28      112
113 #define PT_GPR29      116
114 #define PT_GPR30      120
115 #define PT_GPR31      124
116 #define PT_PC	      128
117 #define PT_ORIG_GPR11 132
118 #define PT_FPCSR      136
119 
120 #endif /* __ASM_OPENRISC_PTRACE_H */
121