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/cacheflush.h>
11 #include <asm/kdebug.h>
12 #include <asm/ptrace.h>
13 #include <asm/irq.h>
14
pt_regs_to_gdb_regs(unsigned long * gdb_regs,struct pt_regs * regs)15 void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
16 {
17 struct reg_window *win;
18 int i;
19
20 gdb_regs[GDB_G0] = 0;
21 for (i = 0; i < 15; i++)
22 gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i];
23
24 win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS);
25 for (i = 0; i < 8; i++)
26 gdb_regs[GDB_L0 + i] = win->locals[i];
27 for (i = 0; i < 8; i++)
28 gdb_regs[GDB_I0 + i] = win->ins[i];
29
30 for (i = GDB_F0; i <= GDB_F62; i++)
31 gdb_regs[i] = 0;
32
33 gdb_regs[GDB_PC] = regs->tpc;
34 gdb_regs[GDB_NPC] = regs->tnpc;
35 gdb_regs[GDB_STATE] = regs->tstate;
36 gdb_regs[GDB_FSR] = 0;
37 gdb_regs[GDB_FPRS] = 0;
38 gdb_regs[GDB_Y] = regs->y;
39 }
40
sleeping_thread_to_gdb_regs(unsigned long * gdb_regs,struct task_struct * p)41 void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
42 {
43 struct thread_info *t = task_thread_info(p);
44 extern unsigned int switch_to_pc;
45 extern unsigned int ret_from_syscall;
46 struct reg_window *win;
47 unsigned long pc, cwp;
48 int i;
49
50 for (i = GDB_G0; i < GDB_G6; i++)
51 gdb_regs[i] = 0;
52 gdb_regs[GDB_G6] = (unsigned long) t;
53 gdb_regs[GDB_G7] = (unsigned long) p;
54 for (i = GDB_O0; i < GDB_SP; i++)
55 gdb_regs[i] = 0;
56 gdb_regs[GDB_SP] = t->ksp;
57 gdb_regs[GDB_O7] = 0;
58
59 win = (struct reg_window *) (t->ksp + STACK_BIAS);
60 for (i = 0; i < 8; i++)
61 gdb_regs[GDB_L0 + i] = win->locals[i];
62 for (i = 0; i < 8; i++)
63 gdb_regs[GDB_I0 + i] = win->ins[i];
64
65 for (i = GDB_F0; i <= GDB_F62; i++)
66 gdb_regs[i] = 0;
67
68 if (t->new_child)
69 pc = (unsigned long) &ret_from_syscall;
70 else
71 pc = (unsigned long) &switch_to_pc;
72
73 gdb_regs[GDB_PC] = pc;
74 gdb_regs[GDB_NPC] = pc + 4;
75
76 cwp = __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP];
77
78 gdb_regs[GDB_STATE] = (TSTATE_PRIV | TSTATE_IE | cwp);
79 gdb_regs[GDB_FSR] = 0;
80 gdb_regs[GDB_FPRS] = 0;
81 gdb_regs[GDB_Y] = 0;
82 }
83
gdb_regs_to_pt_regs(unsigned long * gdb_regs,struct pt_regs * regs)84 void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
85 {
86 struct reg_window *win;
87 int i;
88
89 for (i = 0; i < 15; i++)
90 regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i];
91
92 /* If the TSTATE register is changing, we have to preserve
93 * the CWP field, otherwise window save/restore explodes.
94 */
95 if (regs->tstate != gdb_regs[GDB_STATE]) {
96 unsigned long cwp = regs->tstate & TSTATE_CWP;
97
98 regs->tstate = (gdb_regs[GDB_STATE] & ~TSTATE_CWP) | cwp;
99 }
100
101 regs->tpc = gdb_regs[GDB_PC];
102 regs->tnpc = gdb_regs[GDB_NPC];
103 regs->y = gdb_regs[GDB_Y];
104
105 win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS);
106 for (i = 0; i < 8; i++)
107 win->locals[i] = gdb_regs[GDB_L0 + i];
108 for (i = 0; i < 8; i++)
109 win->ins[i] = gdb_regs[GDB_I0 + i];
110 }
111
112 #ifdef CONFIG_SMP
smp_kgdb_capture_client(int irq,struct pt_regs * regs)113 void __irq_entry smp_kgdb_capture_client(int irq, struct pt_regs *regs)
114 {
115 unsigned long flags;
116
117 __asm__ __volatile__("rdpr %%pstate, %0\n\t"
118 "wrpr %0, %1, %%pstate"
119 : "=r" (flags)
120 : "i" (PSTATE_IE));
121
122 flushw_all();
123
124 if (atomic_read(&kgdb_active) != -1)
125 kgdb_nmicallback(raw_smp_processor_id(), regs);
126
127 __asm__ __volatile__("wrpr %0, 0, %%pstate"
128 : : "r" (flags));
129 }
130 #endif
131
kgdb_arch_handle_exception(int e_vector,int signo,int err_code,char * remcomInBuffer,char * remcomOutBuffer,struct pt_regs * linux_regs)132 int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
133 char *remcomInBuffer, char *remcomOutBuffer,
134 struct pt_regs *linux_regs)
135 {
136 unsigned long addr;
137 char *ptr;
138
139 switch (remcomInBuffer[0]) {
140 case 'c':
141 /* try to read optional parameter, pc unchanged if no parm */
142 ptr = &remcomInBuffer[1];
143 if (kgdb_hex2long(&ptr, &addr)) {
144 linux_regs->tpc = addr;
145 linux_regs->tnpc = addr + 4;
146 }
147 /* fallthru */
148
149 case 'D':
150 case 'k':
151 if (linux_regs->tpc == (unsigned long) arch_kgdb_breakpoint) {
152 linux_regs->tpc = linux_regs->tnpc;
153 linux_regs->tnpc += 4;
154 }
155 return 0;
156 }
157 return -1;
158 }
159
kgdb_trap(unsigned long trap_level,struct pt_regs * regs)160 asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs)
161 {
162 unsigned long flags;
163
164 if (user_mode(regs)) {
165 bad_trap(regs, trap_level);
166 return;
167 }
168
169 flushw_all();
170
171 local_irq_save(flags);
172 kgdb_handle_exception(0x172, SIGTRAP, 0, regs);
173 local_irq_restore(flags);
174 }
175
kgdb_arch_init(void)176 int kgdb_arch_init(void)
177 {
178 return 0;
179 }
180
kgdb_arch_exit(void)181 void kgdb_arch_exit(void)
182 {
183 }
184
kgdb_arch_set_pc(struct pt_regs * regs,unsigned long ip)185 void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
186 {
187 regs->tpc = ip;
188 regs->tnpc = regs->tpc + 4;
189 }
190
191 struct kgdb_arch arch_kgdb_ops = {
192 /* Breakpoint instruction: ta 0x72 */
193 .gdb_bpt_instr = { 0x91, 0xd0, 0x20, 0x72 },
194 };
195