1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* kgdb.c: KGDB support for 32-bit sparc. |
3 | * |
4 | * Copyright (C) 2008 David S. Miller <davem@davemloft.net> |
5 | */ |
6 | |
7 | #include <linux/kgdb.h> |
8 | #include <linux/kdebug.h> |
9 | #include <linux/sched.h> |
10 | |
11 | #include <asm/kdebug.h> |
12 | #include <asm/ptrace.h> |
13 | #include <asm/irq.h> |
14 | #include <asm/cacheflush.h> |
15 | |
16 | #include "kernel.h" |
17 | #include "entry.h" |
18 | |
19 | void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) |
20 | { |
21 | struct reg_window32 *win; |
22 | int i; |
23 | |
24 | gdb_regs[GDB_G0] = 0; |
25 | for (i = 0; i < 15; i++) |
26 | gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i]; |
27 | |
28 | win = (struct reg_window32 *) regs->u_regs[UREG_FP]; |
29 | for (i = 0; i < 8; i++) |
30 | gdb_regs[GDB_L0 + i] = win->locals[i]; |
31 | for (i = 0; i < 8; i++) |
32 | gdb_regs[GDB_I0 + i] = win->ins[i]; |
33 | |
34 | for (i = GDB_F0; i <= GDB_F31; i++) |
35 | gdb_regs[i] = 0; |
36 | |
37 | gdb_regs[GDB_Y] = regs->y; |
38 | gdb_regs[GDB_PSR] = regs->psr; |
39 | gdb_regs[GDB_WIM] = 0; |
40 | gdb_regs[GDB_TBR] = (unsigned long) &trapbase[0]; |
41 | gdb_regs[GDB_PC] = regs->pc; |
42 | gdb_regs[GDB_NPC] = regs->npc; |
43 | gdb_regs[GDB_FSR] = 0; |
44 | gdb_regs[GDB_CSR] = 0; |
45 | } |
46 | |
47 | void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) |
48 | { |
49 | struct thread_info *t = task_thread_info(p); |
50 | struct reg_window32 *win; |
51 | int i; |
52 | |
53 | for (i = GDB_G0; i < GDB_G6; i++) |
54 | gdb_regs[i] = 0; |
55 | gdb_regs[GDB_G6] = (unsigned long) t; |
56 | gdb_regs[GDB_G7] = 0; |
57 | for (i = GDB_O0; i < GDB_SP; i++) |
58 | gdb_regs[i] = 0; |
59 | gdb_regs[GDB_SP] = t->ksp; |
60 | gdb_regs[GDB_O7] = 0; |
61 | |
62 | win = (struct reg_window32 *) t->ksp; |
63 | for (i = 0; i < 8; i++) |
64 | gdb_regs[GDB_L0 + i] = win->locals[i]; |
65 | for (i = 0; i < 8; i++) |
66 | gdb_regs[GDB_I0 + i] = win->ins[i]; |
67 | |
68 | for (i = GDB_F0; i <= GDB_F31; i++) |
69 | gdb_regs[i] = 0; |
70 | |
71 | gdb_regs[GDB_Y] = 0; |
72 | |
73 | gdb_regs[GDB_PSR] = t->kpsr; |
74 | gdb_regs[GDB_WIM] = t->kwim; |
75 | gdb_regs[GDB_TBR] = (unsigned long) &trapbase[0]; |
76 | gdb_regs[GDB_PC] = t->kpc; |
77 | gdb_regs[GDB_NPC] = t->kpc + 4; |
78 | gdb_regs[GDB_FSR] = 0; |
79 | gdb_regs[GDB_CSR] = 0; |
80 | } |
81 | |
82 | void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) |
83 | { |
84 | struct reg_window32 *win; |
85 | int i; |
86 | |
87 | for (i = 0; i < 15; i++) |
88 | regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i]; |
89 | |
90 | /* If the PSR register is changing, we have to preserve |
91 | * the CWP field, otherwise window save/restore explodes. |
92 | */ |
93 | if (regs->psr != gdb_regs[GDB_PSR]) { |
94 | unsigned long cwp = regs->psr & PSR_CWP; |
95 | |
96 | regs->psr = (gdb_regs[GDB_PSR] & ~PSR_CWP) | cwp; |
97 | } |
98 | |
99 | regs->pc = gdb_regs[GDB_PC]; |
100 | regs->npc = gdb_regs[GDB_NPC]; |
101 | regs->y = gdb_regs[GDB_Y]; |
102 | |
103 | win = (struct reg_window32 *) regs->u_regs[UREG_FP]; |
104 | for (i = 0; i < 8; i++) |
105 | win->locals[i] = gdb_regs[GDB_L0 + i]; |
106 | for (i = 0; i < 8; i++) |
107 | win->ins[i] = gdb_regs[GDB_I0 + i]; |
108 | } |
109 | |
110 | int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, |
111 | char *remcomInBuffer, char *remcomOutBuffer, |
112 | struct pt_regs *linux_regs) |
113 | { |
114 | unsigned long addr; |
115 | char *ptr; |
116 | |
117 | switch (remcomInBuffer[0]) { |
118 | case 'c': |
119 | /* try to read optional parameter, pc unchanged if no parm */ |
120 | ptr = &remcomInBuffer[1]; |
121 | if (kgdb_hex2long(ptr: &ptr, long_val: &addr)) { |
122 | linux_regs->pc = addr; |
123 | linux_regs->npc = addr + 4; |
124 | } |
125 | fallthrough; |
126 | |
127 | case 'D': |
128 | case 'k': |
129 | if (linux_regs->pc == (unsigned long) arch_kgdb_breakpoint) { |
130 | linux_regs->pc = linux_regs->npc; |
131 | linux_regs->npc += 4; |
132 | } |
133 | return 0; |
134 | } |
135 | return -1; |
136 | } |
137 | |
138 | asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs) |
139 | { |
140 | unsigned long flags; |
141 | |
142 | if (user_mode(regs)) { |
143 | do_hw_interrupt(regs, trap_level); |
144 | return; |
145 | } |
146 | |
147 | flushw_all(); |
148 | |
149 | local_irq_save(flags); |
150 | kgdb_handle_exception(ex_vector: trap_level, SIGTRAP, err_code: 0, regs); |
151 | local_irq_restore(flags); |
152 | } |
153 | |
154 | int kgdb_arch_init(void) |
155 | { |
156 | return 0; |
157 | } |
158 | |
159 | void kgdb_arch_exit(void) |
160 | { |
161 | } |
162 | |
163 | void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) |
164 | { |
165 | regs->pc = ip; |
166 | regs->npc = regs->pc + 4; |
167 | } |
168 | |
169 | const struct kgdb_arch arch_kgdb_ops = { |
170 | /* Breakpoint instruction: ta 0x7d */ |
171 | .gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x7d }, |
172 | }; |
173 | |