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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
e2fdd7fd DM |
2 | /* kgdb.c: KGDB support for 64-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> | |
9960e9e8 | 9 | #include <linux/ftrace.h> |
1de425c7 | 10 | #include <linux/context_tracking.h> |
e2fdd7fd | 11 | |
8befc9f2 | 12 | #include <asm/cacheflush.h> |
e2fdd7fd DM |
13 | #include <asm/kdebug.h> |
14 | #include <asm/ptrace.h> | |
15 | #include <asm/irq.h> | |
16 | ||
48c7eca5 SR |
17 | #include "kernel.h" |
18 | ||
e2fdd7fd DM |
19 | void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) |
20 | { | |
21 | struct reg_window *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_window *) (regs->u_regs[UREG_FP] + STACK_BIAS); | |
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_F62; i++) | |
35 | gdb_regs[i] = 0; | |
36 | ||
37 | gdb_regs[GDB_PC] = regs->tpc; | |
38 | gdb_regs[GDB_NPC] = regs->tnpc; | |
39 | gdb_regs[GDB_STATE] = regs->tstate; | |
40 | gdb_regs[GDB_FSR] = 0; | |
41 | gdb_regs[GDB_FPRS] = 0; | |
42 | gdb_regs[GDB_Y] = regs->y; | |
43 | } | |
44 | ||
45 | void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p) | |
46 | { | |
47 | struct thread_info *t = task_thread_info(p); | |
48 | extern unsigned int switch_to_pc; | |
37d6fa34 | 49 | extern unsigned int ret_from_fork; |
e2fdd7fd DM |
50 | struct reg_window *win; |
51 | unsigned long pc, cwp; | |
52 | int i; | |
53 | ||
54 | for (i = GDB_G0; i < GDB_G6; i++) | |
55 | gdb_regs[i] = 0; | |
56 | gdb_regs[GDB_G6] = (unsigned long) t; | |
57 | gdb_regs[GDB_G7] = (unsigned long) p; | |
58 | for (i = GDB_O0; i < GDB_SP; i++) | |
59 | gdb_regs[i] = 0; | |
60 | gdb_regs[GDB_SP] = t->ksp; | |
61 | gdb_regs[GDB_O7] = 0; | |
62 | ||
63 | win = (struct reg_window *) (t->ksp + STACK_BIAS); | |
64 | for (i = 0; i < 8; i++) | |
65 | gdb_regs[GDB_L0 + i] = win->locals[i]; | |
66 | for (i = 0; i < 8; i++) | |
67 | gdb_regs[GDB_I0 + i] = win->ins[i]; | |
68 | ||
69 | for (i = GDB_F0; i <= GDB_F62; i++) | |
70 | gdb_regs[i] = 0; | |
71 | ||
72 | if (t->new_child) | |
37d6fa34 | 73 | pc = (unsigned long) &ret_from_fork; |
e2fdd7fd DM |
74 | else |
75 | pc = (unsigned long) &switch_to_pc; | |
76 | ||
77 | gdb_regs[GDB_PC] = pc; | |
78 | gdb_regs[GDB_NPC] = pc + 4; | |
79 | ||
80 | cwp = __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP]; | |
81 | ||
82 | gdb_regs[GDB_STATE] = (TSTATE_PRIV | TSTATE_IE | cwp); | |
83 | gdb_regs[GDB_FSR] = 0; | |
84 | gdb_regs[GDB_FPRS] = 0; | |
85 | gdb_regs[GDB_Y] = 0; | |
86 | } | |
87 | ||
88 | void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) | |
89 | { | |
90 | struct reg_window *win; | |
91 | int i; | |
92 | ||
93 | for (i = 0; i < 15; i++) | |
94 | regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i]; | |
95 | ||
96 | /* If the TSTATE register is changing, we have to preserve | |
97 | * the CWP field, otherwise window save/restore explodes. | |
98 | */ | |
99 | if (regs->tstate != gdb_regs[GDB_STATE]) { | |
100 | unsigned long cwp = regs->tstate & TSTATE_CWP; | |
101 | ||
102 | regs->tstate = (gdb_regs[GDB_STATE] & ~TSTATE_CWP) | cwp; | |
103 | } | |
104 | ||
105 | regs->tpc = gdb_regs[GDB_PC]; | |
106 | regs->tnpc = gdb_regs[GDB_NPC]; | |
107 | regs->y = gdb_regs[GDB_Y]; | |
108 | ||
109 | win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS); | |
110 | for (i = 0; i < 8; i++) | |
111 | win->locals[i] = gdb_regs[GDB_L0 + i]; | |
112 | for (i = 0; i < 8; i++) | |
113 | win->ins[i] = gdb_regs[GDB_I0 + i]; | |
114 | } | |
115 | ||
116 | #ifdef CONFIG_SMP | |
9960e9e8 | 117 | void __irq_entry smp_kgdb_capture_client(int irq, struct pt_regs *regs) |
e2fdd7fd DM |
118 | { |
119 | unsigned long flags; | |
120 | ||
121 | __asm__ __volatile__("rdpr %%pstate, %0\n\t" | |
122 | "wrpr %0, %1, %%pstate" | |
123 | : "=r" (flags) | |
124 | : "i" (PSTATE_IE)); | |
125 | ||
126 | flushw_all(); | |
127 | ||
128 | if (atomic_read(&kgdb_active) != -1) | |
129 | kgdb_nmicallback(raw_smp_processor_id(), regs); | |
130 | ||
131 | __asm__ __volatile__("wrpr %0, 0, %%pstate" | |
132 | : : "r" (flags)); | |
133 | } | |
134 | #endif | |
135 | ||
136 | int kgdb_arch_handle_exception(int e_vector, int signo, int err_code, | |
137 | char *remcomInBuffer, char *remcomOutBuffer, | |
138 | struct pt_regs *linux_regs) | |
139 | { | |
140 | unsigned long addr; | |
141 | char *ptr; | |
142 | ||
143 | switch (remcomInBuffer[0]) { | |
144 | case 'c': | |
145 | /* try to read optional parameter, pc unchanged if no parm */ | |
146 | ptr = &remcomInBuffer[1]; | |
147 | if (kgdb_hex2long(&ptr, &addr)) { | |
148 | linux_regs->tpc = addr; | |
149 | linux_regs->tnpc = addr + 4; | |
150 | } | |
151 | /* fallthru */ | |
152 | ||
153 | case 'D': | |
154 | case 'k': | |
155 | if (linux_regs->tpc == (unsigned long) arch_kgdb_breakpoint) { | |
156 | linux_regs->tpc = linux_regs->tnpc; | |
157 | linux_regs->tnpc += 4; | |
158 | } | |
159 | return 0; | |
160 | } | |
161 | return -1; | |
162 | } | |
163 | ||
164 | asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs) | |
165 | { | |
812cb83a | 166 | enum ctx_state prev_state = exception_enter(); |
e2fdd7fd DM |
167 | unsigned long flags; |
168 | ||
169 | if (user_mode(regs)) { | |
170 | bad_trap(regs, trap_level); | |
812cb83a | 171 | goto out; |
e2fdd7fd DM |
172 | } |
173 | ||
174 | flushw_all(); | |
175 | ||
176 | local_irq_save(flags); | |
177 | kgdb_handle_exception(0x172, SIGTRAP, 0, regs); | |
178 | local_irq_restore(flags); | |
812cb83a KT |
179 | out: |
180 | exception_exit(prev_state); | |
e2fdd7fd DM |
181 | } |
182 | ||
183 | int kgdb_arch_init(void) | |
184 | { | |
185 | return 0; | |
186 | } | |
187 | ||
188 | void kgdb_arch_exit(void) | |
189 | { | |
190 | } | |
191 | ||
c75fbb05 JW |
192 | void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) |
193 | { | |
194 | regs->tpc = ip; | |
195 | regs->tnpc = regs->tpc + 4; | |
196 | } | |
197 | ||
e2fdd7fd DM |
198 | struct kgdb_arch arch_kgdb_ops = { |
199 | /* Breakpoint instruction: ta 0x72 */ | |
200 | .gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x72 }, | |
201 | }; |