1 /* kgdb.c: KGDB support for 64-bit sparc.
2 *
3 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
4 */
5
6 #include <linux/kgdb.h>
7 #include <linux/kdebug.h>
8 #include <linux/ftrace.h>
9
10 #include <asm/kdebug.h>
11 #include <asm/ptrace.h>
12 #include <asm/irq.h>
13
pt_regs_to_gdb_regs(unsigned long * gdb_regs,struct pt_regs * regs)14 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
15 {
16 struct reg_window *win;
17 int i;
18
19 gdb_regs[GDB_G0] = 0;
20 for (i = 0; i < 15; i++)
21 gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i];
22
23 win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS);
24 for (i = 0; i < 8; i++)
25 gdb_regs[GDB_L0 + i] = win->locals[i];
26 for (i = 0; i < 8; i++)
27 gdb_regs[GDB_I0 + i] = win->ins[i];
28
29 for (i = GDB_F0; i <= GDB_F62; i++)
30 gdb_regs[i] = 0;
31
32 gdb_regs[GDB_PC] = regs->tpc;
33 gdb_regs[GDB_NPC] = regs->tnpc;
34 gdb_regs[GDB_STATE] = regs->tstate;
35 gdb_regs[GDB_FSR] = 0;
36 gdb_regs[GDB_FPRS] = 0;
37 gdb_regs[GDB_Y] = regs->y;
38 }
39
sleeping_thread_to_gdb_regs(unsigned long * gdb_regs,struct task_struct * p)40 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
41 {
42 struct thread_info *t = task_thread_info(p);
43 extern unsigned int switch_to_pc;
44 extern unsigned int ret_from_syscall;
45 struct reg_window *win;
46 unsigned long pc, cwp;
47 int i;
48
49 for (i = GDB_G0; i < GDB_G6; i++)
50 gdb_regs[i] = 0;
51 gdb_regs[GDB_G6] = (unsigned long) t;
52 gdb_regs[GDB_G7] = (unsigned long) p;
53 for (i = GDB_O0; i < GDB_SP; i++)
54 gdb_regs[i] = 0;
55 gdb_regs[GDB_SP] = t->ksp;
56 gdb_regs[GDB_O7] = 0;
57
58 win = (struct reg_window *) (t->ksp + STACK_BIAS);
59 for (i = 0; i < 8; i++)
60 gdb_regs[GDB_L0 + i] = win->locals[i];
61 for (i = 0; i < 8; i++)
62 gdb_regs[GDB_I0 + i] = win->ins[i];
63
64 for (i = GDB_F0; i <= GDB_F62; i++)
65 gdb_regs[i] = 0;
66
67 if (t->new_child)
68 pc = (unsigned long) &ret_from_syscall;
69 else
70 pc = (unsigned long) &switch_to_pc;
71
72 gdb_regs[GDB_PC] = pc;
73 gdb_regs[GDB_NPC] = pc + 4;
74
75 cwp = __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP];
76
77 gdb_regs[GDB_STATE] = (TSTATE_PRIV | TSTATE_IE | cwp);
78 gdb_regs[GDB_FSR] = 0;
79 gdb_regs[GDB_FPRS] = 0;
80 gdb_regs[GDB_Y] = 0;
81 }
82
gdb_regs_to_pt_regs(unsigned long * gdb_regs,struct pt_regs * regs)83 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
84 {
85 struct reg_window *win;
86 int i;
87
88 for (i = 0; i < 15; i++)
89 regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i];
90
91 /* If the TSTATE register is changing, we have to preserve
92 * the CWP field, otherwise window save/restore explodes.
93 */
94 if (regs->tstate != gdb_regs[GDB_STATE]) {
95 unsigned long cwp = regs->tstate & TSTATE_CWP;
96
97 regs->tstate = (gdb_regs[GDB_STATE] & ~TSTATE_CWP) | cwp;
98 }
99
100 regs->tpc = gdb_regs[GDB_PC];
101 regs->tnpc = gdb_regs[GDB_NPC];
102 regs->y = gdb_regs[GDB_Y];
103
104 win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS);
105 for (i = 0; i < 8; i++)
106 win->locals[i] = gdb_regs[GDB_L0 + i];
107 for (i = 0; i < 8; i++)
108 win->ins[i] = gdb_regs[GDB_I0 + i];
109 }
110
111 #ifdef CONFIG_SMP
smp_kgdb_capture_client(int irq,struct pt_regs * regs)112 void __irq_entry smp_kgdb_capture_client(int irq, struct pt_regs *regs)
113 {
114 unsigned long flags;
115
116 __asm__ __volatile__("rdpr %%pstate, %0\n\t"
117 "wrpr %0, %1, %%pstate"
118 : "=r" (flags)
119 : "i" (PSTATE_IE));
120
121 flushw_all();
122
123 if (atomic_read(&kgdb_active) != -1)
124 kgdb_nmicallback(raw_smp_processor_id(), regs);
125
126 __asm__ __volatile__("wrpr %0, 0, %%pstate"
127 : : "r" (flags));
128 }
129 #endif
130
kgdb_arch_handle_exception(int e_vector,int signo,int err_code,char * remcomInBuffer,char * remcomOutBuffer,struct pt_regs * linux_regs)131 int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
132 char *remcomInBuffer, char *remcomOutBuffer,
133 struct pt_regs *linux_regs)
134 {
135 unsigned long addr;
136 char *ptr;
137
138 switch (remcomInBuffer[0]) {
139 case 'c':
140 /* try to read optional parameter, pc unchanged if no parm */
141 ptr = &remcomInBuffer[1];
142 if (kgdb_hex2long(&ptr, &addr)) {
143 linux_regs->tpc = addr;
144 linux_regs->tnpc = addr + 4;
145 }
146 /* fallthru */
147
148 case 'D':
149 case 'k':
150 if (linux_regs->tpc == (unsigned long) arch_kgdb_breakpoint) {
151 linux_regs->tpc = linux_regs->tnpc;
152 linux_regs->tnpc += 4;
153 }
154 return 0;
155 }
156 return -1;
157 }
158
kgdb_trap(unsigned long trap_level,struct pt_regs * regs)159 asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs)
160 {
161 unsigned long flags;
162
163 if (user_mode(regs)) {
164 bad_trap(regs, trap_level);
165 return;
166 }
167
168 flushw_all();
169
170 local_irq_save(flags);
171 kgdb_handle_exception(0x172, SIGTRAP, 0, regs);
172 local_irq_restore(flags);
173 }
174
kgdb_arch_init(void)175 int kgdb_arch_init(void)
176 {
177 return 0;
178 }
179
kgdb_arch_exit(void)180 void kgdb_arch_exit(void)
181 {
182 }
183
kgdb_arch_set_pc(struct pt_regs * regs,unsigned long ip)184 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
185 {
186 regs->tpc = ip;
187 regs->tnpc = regs->tpc + 4;
188 }
189
190 struct kgdb_arch arch_kgdb_ops = {
191 /* Breakpoint instruction: ta 0x72 */
192 .gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x72 },
193 };
194