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1/*
2 * kgdb support for ARC
3 *
4 * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/kgdb.h>
12#include <linux/sched.h>
13#include <asm/disasm.h>
14#include <asm/cacheflush.h>
15
16static void to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs,
17 struct callee_regs *cregs)
18{
19 int regno;
20
21 for (regno = 0; regno <= 26; regno++)
22 gdb_regs[_R0 + regno] = get_reg(regno, kernel_regs, cregs);
23
24 for (regno = 27; regno < GDB_MAX_REGS; regno++)
25 gdb_regs[regno] = 0;
26
27 gdb_regs[_FP] = kernel_regs->fp;
28 gdb_regs[__SP] = kernel_regs->sp;
29 gdb_regs[_BLINK] = kernel_regs->blink;
30 gdb_regs[_RET] = kernel_regs->ret;
31 gdb_regs[_STATUS32] = kernel_regs->status32;
32 gdb_regs[_LP_COUNT] = kernel_regs->lp_count;
33 gdb_regs[_LP_END] = kernel_regs->lp_end;
34 gdb_regs[_LP_START] = kernel_regs->lp_start;
35 gdb_regs[_BTA] = kernel_regs->bta;
36 gdb_regs[_STOP_PC] = kernel_regs->ret;
37}
38
39static void from_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs,
40 struct callee_regs *cregs)
41{
42 int regno;
43
44 for (regno = 0; regno <= 26; regno++)
45 set_reg(regno, gdb_regs[regno + _R0], kernel_regs, cregs);
46
47 kernel_regs->fp = gdb_regs[_FP];
48 kernel_regs->sp = gdb_regs[__SP];
49 kernel_regs->blink = gdb_regs[_BLINK];
50 kernel_regs->ret = gdb_regs[_RET];
51 kernel_regs->status32 = gdb_regs[_STATUS32];
52 kernel_regs->lp_count = gdb_regs[_LP_COUNT];
53 kernel_regs->lp_end = gdb_regs[_LP_END];
54 kernel_regs->lp_start = gdb_regs[_LP_START];
55 kernel_regs->bta = gdb_regs[_BTA];
56}
57
58
59void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
60{
61 to_gdb_regs(gdb_regs, kernel_regs, (struct callee_regs *)
62 current->thread.callee_reg);
63}
64
65void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
66{
67 from_gdb_regs(gdb_regs, kernel_regs, (struct callee_regs *)
68 current->thread.callee_reg);
69}
70
71void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs,
72 struct task_struct *task)
73{
74 if (task)
75 to_gdb_regs(gdb_regs, task_pt_regs(task),
76 (struct callee_regs *) task->thread.callee_reg);
77}
78
79struct single_step_data_t {
80 uint16_t opcode[2];
81 unsigned long address[2];
82 int is_branch;
83 int armed;
84} single_step_data;
85
86static void undo_single_step(struct pt_regs *regs)
87{
88 if (single_step_data.armed) {
89 int i;
90
91 for (i = 0; i < (single_step_data.is_branch ? 2 : 1); i++) {
92 memcpy((void *) single_step_data.address[i],
93 &single_step_data.opcode[i],
94 BREAK_INSTR_SIZE);
95
96 flush_icache_range(single_step_data.address[i],
97 single_step_data.address[i] +
98 BREAK_INSTR_SIZE);
99 }
100 single_step_data.armed = 0;
101 }
102}
103
104static void place_trap(unsigned long address, void *save)
105{
106 memcpy(save, (void *) address, BREAK_INSTR_SIZE);
107 memcpy((void *) address, &arch_kgdb_ops.gdb_bpt_instr,
108 BREAK_INSTR_SIZE);
109 flush_icache_range(address, address + BREAK_INSTR_SIZE);
110}
111
112static void do_single_step(struct pt_regs *regs)
113{
114 single_step_data.is_branch = disasm_next_pc((unsigned long)
115 regs->ret, regs, (struct callee_regs *)
116 current->thread.callee_reg,
117 &single_step_data.address[0],
118 &single_step_data.address[1]);
119
120 place_trap(single_step_data.address[0], &single_step_data.opcode[0]);
121
122 if (single_step_data.is_branch) {
123 place_trap(single_step_data.address[1],
124 &single_step_data.opcode[1]);
125 }
126
127 single_step_data.armed++;
128}
129
130int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
131 char *remcomInBuffer, char *remcomOutBuffer,
132 struct pt_regs *regs)
133{
134 unsigned long addr;
135 char *ptr;
136
137 undo_single_step(regs);
138
139 switch (remcomInBuffer[0]) {
140 case 's':
141 case 'c':
142 ptr = &remcomInBuffer[1];
143 if (kgdb_hex2long(&ptr, &addr))
144 regs->ret = addr;
145
146 case 'D':
147 case 'k':
148 atomic_set(&kgdb_cpu_doing_single_step, -1);
149
150 if (remcomInBuffer[0] == 's') {
151 do_single_step(regs);
152 atomic_set(&kgdb_cpu_doing_single_step,
153 smp_processor_id());
154 }
155
156 return 0;
157 }
158 return -1;
159}
160
161unsigned long kgdb_arch_pc(int exception, struct pt_regs *regs)
162{
163 return instruction_pointer(regs);
164}
165
166int kgdb_arch_init(void)
167{
168 single_step_data.armed = 0;
169 return 0;
170}
171
172void kgdb_trap(struct pt_regs *regs)
173{
174 /* trap_s 3 is used for breakpoints that overwrite existing
175 * instructions, while trap_s 4 is used for compiled breakpoints.
176 *
177 * with trap_s 3 breakpoints the original instruction needs to be
178 * restored and continuation needs to start at the location of the
179 * breakpoint.
180 *
181 * with trap_s 4 (compiled) breakpoints, continuation needs to
182 * start after the breakpoint.
183 */
184 if (regs->ecr_param == 3)
185 instruction_pointer(regs) -= BREAK_INSTR_SIZE;
186
187 kgdb_handle_exception(1, SIGTRAP, 0, regs);
188}
189
190void kgdb_arch_exit(void)
191{
192}
193
194void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
195{
196 instruction_pointer(regs) = ip;
197}
198
199static void kgdb_call_nmi_hook(void *ignored)
200{
201 kgdb_nmicallback(raw_smp_processor_id(), NULL);
202}
203
204void kgdb_roundup_cpus(unsigned long flags)
205{
206 local_irq_enable();
207 smp_call_function(kgdb_call_nmi_hook, NULL, 0);
208 local_irq_disable();
209}
210
211struct kgdb_arch arch_kgdb_ops = {
212 /* breakpoint instruction: TRAP_S 0x3 */
213#ifdef CONFIG_CPU_BIG_ENDIAN
214 .gdb_bpt_instr = {0x78, 0x7e},
215#else
216 .gdb_bpt_instr = {0x7e, 0x78},
217#endif
218};
1/*
2 * kgdb support for ARC
3 *
4 * Copyright (C) 2012 Synopsys, Inc. (www.synopsys.com)
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/kgdb.h>
12#include <linux/sched.h>
13#include <linux/sched/task_stack.h>
14#include <asm/disasm.h>
15#include <asm/cacheflush.h>
16
17static void to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs,
18 struct callee_regs *cregs)
19{
20 int regno;
21
22 for (regno = 0; regno <= 26; regno++)
23 gdb_regs[_R0 + regno] = get_reg(regno, kernel_regs, cregs);
24
25 for (regno = 27; regno < GDB_MAX_REGS; regno++)
26 gdb_regs[regno] = 0;
27
28 gdb_regs[_FP] = kernel_regs->fp;
29 gdb_regs[__SP] = kernel_regs->sp;
30 gdb_regs[_BLINK] = kernel_regs->blink;
31 gdb_regs[_RET] = kernel_regs->ret;
32 gdb_regs[_STATUS32] = kernel_regs->status32;
33 gdb_regs[_LP_COUNT] = kernel_regs->lp_count;
34 gdb_regs[_LP_END] = kernel_regs->lp_end;
35 gdb_regs[_LP_START] = kernel_regs->lp_start;
36 gdb_regs[_BTA] = kernel_regs->bta;
37 gdb_regs[_STOP_PC] = kernel_regs->ret;
38}
39
40static void from_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs,
41 struct callee_regs *cregs)
42{
43 int regno;
44
45 for (regno = 0; regno <= 26; regno++)
46 set_reg(regno, gdb_regs[regno + _R0], kernel_regs, cregs);
47
48 kernel_regs->fp = gdb_regs[_FP];
49 kernel_regs->sp = gdb_regs[__SP];
50 kernel_regs->blink = gdb_regs[_BLINK];
51 kernel_regs->ret = gdb_regs[_RET];
52 kernel_regs->status32 = gdb_regs[_STATUS32];
53 kernel_regs->lp_count = gdb_regs[_LP_COUNT];
54 kernel_regs->lp_end = gdb_regs[_LP_END];
55 kernel_regs->lp_start = gdb_regs[_LP_START];
56 kernel_regs->bta = gdb_regs[_BTA];
57}
58
59
60void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
61{
62 to_gdb_regs(gdb_regs, kernel_regs, (struct callee_regs *)
63 current->thread.callee_reg);
64}
65
66void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
67{
68 from_gdb_regs(gdb_regs, kernel_regs, (struct callee_regs *)
69 current->thread.callee_reg);
70}
71
72void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs,
73 struct task_struct *task)
74{
75 if (task)
76 to_gdb_regs(gdb_regs, task_pt_regs(task),
77 (struct callee_regs *) task->thread.callee_reg);
78}
79
80struct single_step_data_t {
81 uint16_t opcode[2];
82 unsigned long address[2];
83 int is_branch;
84 int armed;
85} single_step_data;
86
87static void undo_single_step(struct pt_regs *regs)
88{
89 if (single_step_data.armed) {
90 int i;
91
92 for (i = 0; i < (single_step_data.is_branch ? 2 : 1); i++) {
93 memcpy((void *) single_step_data.address[i],
94 &single_step_data.opcode[i],
95 BREAK_INSTR_SIZE);
96
97 flush_icache_range(single_step_data.address[i],
98 single_step_data.address[i] +
99 BREAK_INSTR_SIZE);
100 }
101 single_step_data.armed = 0;
102 }
103}
104
105static void place_trap(unsigned long address, void *save)
106{
107 memcpy(save, (void *) address, BREAK_INSTR_SIZE);
108 memcpy((void *) address, &arch_kgdb_ops.gdb_bpt_instr,
109 BREAK_INSTR_SIZE);
110 flush_icache_range(address, address + BREAK_INSTR_SIZE);
111}
112
113static void do_single_step(struct pt_regs *regs)
114{
115 single_step_data.is_branch = disasm_next_pc((unsigned long)
116 regs->ret, regs, (struct callee_regs *)
117 current->thread.callee_reg,
118 &single_step_data.address[0],
119 &single_step_data.address[1]);
120
121 place_trap(single_step_data.address[0], &single_step_data.opcode[0]);
122
123 if (single_step_data.is_branch) {
124 place_trap(single_step_data.address[1],
125 &single_step_data.opcode[1]);
126 }
127
128 single_step_data.armed++;
129}
130
131int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
132 char *remcomInBuffer, char *remcomOutBuffer,
133 struct pt_regs *regs)
134{
135 unsigned long addr;
136 char *ptr;
137
138 undo_single_step(regs);
139
140 switch (remcomInBuffer[0]) {
141 case 's':
142 case 'c':
143 ptr = &remcomInBuffer[1];
144 if (kgdb_hex2long(&ptr, &addr))
145 regs->ret = addr;
146
147 case 'D':
148 case 'k':
149 atomic_set(&kgdb_cpu_doing_single_step, -1);
150
151 if (remcomInBuffer[0] == 's') {
152 do_single_step(regs);
153 atomic_set(&kgdb_cpu_doing_single_step,
154 smp_processor_id());
155 }
156
157 return 0;
158 }
159 return -1;
160}
161
162int kgdb_arch_init(void)
163{
164 single_step_data.armed = 0;
165 return 0;
166}
167
168void kgdb_trap(struct pt_regs *regs)
169{
170 /* trap_s 3 is used for breakpoints that overwrite existing
171 * instructions, while trap_s 4 is used for compiled breakpoints.
172 *
173 * with trap_s 3 breakpoints the original instruction needs to be
174 * restored and continuation needs to start at the location of the
175 * breakpoint.
176 *
177 * with trap_s 4 (compiled) breakpoints, continuation needs to
178 * start after the breakpoint.
179 */
180 if (regs->ecr_param == 3)
181 instruction_pointer(regs) -= BREAK_INSTR_SIZE;
182
183 kgdb_handle_exception(1, SIGTRAP, 0, regs);
184}
185
186void kgdb_arch_exit(void)
187{
188}
189
190void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
191{
192 instruction_pointer(regs) = ip;
193}
194
195static void kgdb_call_nmi_hook(void *ignored)
196{
197 kgdb_nmicallback(raw_smp_processor_id(), NULL);
198}
199
200void kgdb_roundup_cpus(unsigned long flags)
201{
202 local_irq_enable();
203 smp_call_function(kgdb_call_nmi_hook, NULL, 0);
204 local_irq_disable();
205}
206
207struct kgdb_arch arch_kgdb_ops = {
208 /* breakpoint instruction: TRAP_S 0x3 */
209#ifdef CONFIG_CPU_BIG_ENDIAN
210 .gdb_bpt_instr = {0x78, 0x7e},
211#else
212 .gdb_bpt_instr = {0x7e, 0x78},
213#endif
214};