1 /*
2  * include/asm-xtensa/ptrace.h
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file "COPYING" in the main directory of this archive
6  * for more details.
7  *
8  * Copyright (C) 2001 - 2005 Tensilica Inc.
9  */
10 
11 #ifndef _XTENSA_PTRACE_H
12 #define _XTENSA_PTRACE_H
13 
14 /*
15  * Kernel stack
16  *
17  * 		+-----------------------+  -------- STACK_SIZE
18  * 		|     register file     |  |
19  * 		+-----------------------+  |
20  * 		|    struct pt_regs     |  |
21  * 		+-----------------------+  | ------ PT_REGS_OFFSET
22  * double 	:  16 bytes spill area  :  |  ^
23  * excetion 	:- - - - - - - - - - - -:  |  |
24  * frame	:    struct pt_regs     :  |  |
25  * 		:- - - - - - - - - - - -:  |  |
26  * 		|                       |  |  |
27  * 		|     memory stack      |  |  |
28  * 		|                       |  |  |
29  * 		~                       ~  ~  ~
30  * 		~                       ~  ~  ~
31  * 		|                       |  |  |
32  * 		|                       |  |  |
33  * 		+-----------------------+  |  | --- STACK_BIAS
34  * 		|  struct task_struct   |  |  |  ^
35  *  current --> +-----------------------+  |  |  |
36  * 		|  struct thread_info   |  |  |  |
37  *		+-----------------------+ --------
38  */
39 
40 #define KERNEL_STACK_SIZE (2 * PAGE_SIZE)
41 
42 /*  Offsets for exception_handlers[] (3 x 64-entries x 4-byte tables). */
43 
44 #define EXC_TABLE_KSTK		0x004	/* Kernel Stack */
45 #define EXC_TABLE_DOUBLE_SAVE	0x008	/* Double exception save area for a0 */
46 #define EXC_TABLE_FIXUP		0x00c	/* Fixup handler */
47 #define EXC_TABLE_PARAM		0x010	/* For passing a parameter to fixup */
48 #define EXC_TABLE_SYSCALL_SAVE	0x014	/* For fast syscall handler */
49 #define EXC_TABLE_FAST_USER	0x100	/* Fast user exception handler */
50 #define EXC_TABLE_FAST_KERNEL	0x200	/* Fast kernel exception handler */
51 #define EXC_TABLE_DEFAULT	0x300	/* Default C-Handler */
52 #define EXC_TABLE_SIZE		0x400
53 
54 /* Registers used by strace */
55 
56 #define REG_A_BASE	0x0000
57 #define REG_AR_BASE	0x0100
58 #define REG_PC		0x0020
59 #define REG_PS		0x02e6
60 #define REG_WB		0x0248
61 #define REG_WS		0x0249
62 #define REG_LBEG	0x0200
63 #define REG_LEND	0x0201
64 #define REG_LCOUNT	0x0202
65 #define REG_SAR		0x0203
66 
67 #define SYSCALL_NR	0x00ff
68 
69 /* Other PTRACE_ values defined in <linux/ptrace.h> using values 0-9,16,17,24 */
70 
71 #define PTRACE_GETREGS		12
72 #define PTRACE_SETREGS		13
73 #define PTRACE_GETXTREGS	18
74 #define PTRACE_SETXTREGS	19
75 
76 #ifdef __KERNEL__
77 
78 #ifndef __ASSEMBLY__
79 
80 #include <asm/coprocessor.h>
81 
82 /*
83  * This struct defines the way the registers are stored on the
84  * kernel stack during a system call or other kernel entry.
85  */
86 struct pt_regs {
87 	unsigned long pc;		/*   4 */
88 	unsigned long ps;		/*   8 */
89 	unsigned long depc;		/*  12 */
90 	unsigned long exccause;		/*  16 */
91 	unsigned long excvaddr;		/*  20 */
92 	unsigned long debugcause;	/*  24 */
93 	unsigned long wmask;		/*  28 */
94 	unsigned long lbeg;		/*  32 */
95 	unsigned long lend;		/*  36 */
96 	unsigned long lcount;		/*  40 */
97 	unsigned long sar;		/*  44 */
98 	unsigned long windowbase;	/*  48 */
99 	unsigned long windowstart;	/*  52 */
100 	unsigned long syscall;		/*  56 */
101 	unsigned long icountlevel;	/*  60 */
102 	int reserved[1];		/*  64 */
103 
104 	/* Additional configurable registers that are used by the compiler. */
105 	xtregs_opt_t xtregs_opt;
106 
107 	/* Make sure the areg field is 16 bytes aligned. */
108 	int align[0] __attribute__ ((aligned(16)));
109 
110 	/* current register frame.
111 	 * Note: The ESF for kernel exceptions ends after 16 registers!
112 	 */
113 	unsigned long areg[16];		/* 128 (64) */
114 };
115 
116 #include <variant/core.h>
117 
118 # define arch_has_single_step()	(1)
119 # define task_pt_regs(tsk) ((struct pt_regs*) \
120   (task_stack_page(tsk) + KERNEL_STACK_SIZE - (XCHAL_NUM_AREGS-16)*4) - 1)
121 # define user_mode(regs) (((regs)->ps & 0x00000020)!=0)
122 # define instruction_pointer(regs) ((regs)->pc)
123 
124 # ifndef CONFIG_SMP
125 #  define profile_pc(regs) instruction_pointer(regs)
126 # endif
127 
128 #else	/* __ASSEMBLY__ */
129 
130 # include <asm/asm-offsets.h>
131 #define PT_REGS_OFFSET	  (KERNEL_STACK_SIZE - PT_USER_SIZE)
132 
133 #endif	/* !__ASSEMBLY__ */
134 
135 #endif  /* __KERNEL__ */
136 
137 #endif	/* _XTENSA_PTRACE_H */
138