1 /*
2  * Copyright (C) 2012 ARM Ltd.
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15  */
16 #ifndef __ASM_DEBUG_MONITORS_H
17 #define __ASM_DEBUG_MONITORS_H
18 
19 #ifdef __KERNEL__
20 
21 #define	DBG_ESR_EVT(x)		(((x) >> 27) & 0x7)
22 
23 /* AArch64 */
24 #define DBG_ESR_EVT_HWBP	0x0
25 #define DBG_ESR_EVT_HWSS	0x1
26 #define DBG_ESR_EVT_HWWP	0x2
27 #define DBG_ESR_EVT_BRK		0x6
28 
29 /*
30  * Break point instruction encoding
31  */
32 #define BREAK_INSTR_SIZE		4
33 
34 /*
35  * ESR values expected for dynamic and compile time BRK instruction
36  */
37 #define DBG_ESR_VAL_BRK(x)	(0xf2000000 | ((x) & 0xfffff))
38 
39 /*
40  * #imm16 values used for BRK instruction generation
41  * Allowed values for kgbd are 0x400 - 0x7ff
42  * 0x400: for dynamic BRK instruction
43  * 0x401: for compile time BRK instruction
44  */
45 #define KGDB_DYN_DGB_BRK_IMM		0x400
46 #define KDBG_COMPILED_DBG_BRK_IMM	0x401
47 
48 /*
49  * BRK instruction encoding
50  * The #imm16 value should be placed at bits[20:5] within BRK ins
51  */
52 #define AARCH64_BREAK_MON	0xd4200000
53 
54 /*
55  * Extract byte from BRK instruction
56  */
57 #define KGDB_DYN_DGB_BRK_INS_BYTE(x) \
58 	((((AARCH64_BREAK_MON) & 0xffe0001f) >> (x * 8)) & 0xff)
59 
60 /*
61  * Extract byte from BRK #imm16
62  */
63 #define KGBD_DYN_DGB_BRK_IMM_BYTE(x) \
64 	(((((KGDB_DYN_DGB_BRK_IMM) & 0xffff) << 5) >> (x * 8)) & 0xff)
65 
66 #define KGDB_DYN_DGB_BRK_BYTE(x) \
67 	(KGDB_DYN_DGB_BRK_INS_BYTE(x) | KGBD_DYN_DGB_BRK_IMM_BYTE(x))
68 
69 #define  KGDB_DYN_BRK_INS_BYTE0  KGDB_DYN_DGB_BRK_BYTE(0)
70 #define  KGDB_DYN_BRK_INS_BYTE1  KGDB_DYN_DGB_BRK_BYTE(1)
71 #define  KGDB_DYN_BRK_INS_BYTE2  KGDB_DYN_DGB_BRK_BYTE(2)
72 #define  KGDB_DYN_BRK_INS_BYTE3  KGDB_DYN_DGB_BRK_BYTE(3)
73 
74 #define CACHE_FLUSH_IS_SAFE		1
75 
76 enum debug_el {
77 	DBG_ACTIVE_EL0 = 0,
78 	DBG_ACTIVE_EL1,
79 };
80 
81 /* AArch32 */
82 #define DBG_ESR_EVT_BKPT	0x4
83 #define DBG_ESR_EVT_VECC	0x5
84 
85 #define AARCH32_BREAK_ARM	0x07f001f0
86 #define AARCH32_BREAK_THUMB	0xde01
87 #define AARCH32_BREAK_THUMB2_LO	0xf7f0
88 #define AARCH32_BREAK_THUMB2_HI	0xa000
89 
90 #ifndef __ASSEMBLY__
91 struct task_struct;
92 
93 #define DBG_ARCH_ID_RESERVED	0	/* In case of ptrace ABI updates. */
94 
95 #define DBG_HOOK_HANDLED	0
96 #define DBG_HOOK_ERROR		1
97 
98 struct step_hook {
99 	struct list_head node;
100 	int (*fn)(struct pt_regs *regs, unsigned int esr);
101 };
102 
103 void register_step_hook(struct step_hook *hook);
104 void unregister_step_hook(struct step_hook *hook);
105 
106 struct break_hook {
107 	struct list_head node;
108 	u32 esr_val;
109 	u32 esr_mask;
110 	int (*fn)(struct pt_regs *regs, unsigned int esr);
111 };
112 
113 void register_break_hook(struct break_hook *hook);
114 void unregister_break_hook(struct break_hook *hook);
115 
116 u8 debug_monitors_arch(void);
117 
118 void enable_debug_monitors(enum debug_el el);
119 void disable_debug_monitors(enum debug_el el);
120 
121 void user_rewind_single_step(struct task_struct *task);
122 void user_fastforward_single_step(struct task_struct *task);
123 
124 void kernel_enable_single_step(struct pt_regs *regs);
125 void kernel_disable_single_step(void);
126 int kernel_active_single_step(void);
127 
128 #ifdef CONFIG_HAVE_HW_BREAKPOINT
129 int reinstall_suspended_bps(struct pt_regs *regs);
130 #else
131 static inline int reinstall_suspended_bps(struct pt_regs *regs)
132 {
133 	return -ENODEV;
134 }
135 #endif
136 
137 int aarch32_break_handler(struct pt_regs *regs);
138 
139 #endif	/* __ASSEMBLY */
140 #endif	/* __KERNEL__ */
141 #endif	/* __ASM_DEBUG_MONITORS_H */
142