summaryrefslogtreecommitdiffstats
path: root/arch/sparc/kernel/kgdb_64.c
blob: 53c0a82e60308d541271707681b046824ad79456 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
/* kgdb.c: KGDB support for 64-bit sparc.
 *
 * Copyright (C) 2008 David S. Miller <davem@davemloft.net>
 */

#include <linux/kgdb.h>
#include <linux/kdebug.h>
#include <linux/ftrace.h>

#include <asm/cacheflush.h>
#include <asm/kdebug.h>
#include <asm/ptrace.h>
#include <asm/irq.h>

void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
	struct reg_window *win;
	int i;

	gdb_regs[GDB_G0] = 0;
	for (i = 0; i < 15; i++)
		gdb_regs[GDB_G1 + i] = regs->u_regs[UREG_G1 + i];

	win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS);
	for (i = 0; i < 8; i++)
		gdb_regs[GDB_L0 + i] = win->locals[i];
	for (i = 0; i < 8; i++)
		gdb_regs[GDB_I0 + i] = win->ins[i];

	for (i = GDB_F0; i <= GDB_F62; i++)
		gdb_regs[i] = 0;

	gdb_regs[GDB_PC] = regs->tpc;
	gdb_regs[GDB_NPC] = regs->tnpc;
	gdb_regs[GDB_STATE] = regs->tstate;
	gdb_regs[GDB_FSR] = 0;
	gdb_regs[GDB_FPRS] = 0;
	gdb_regs[GDB_Y] = regs->y;
}

void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
{
	struct thread_info *t = task_thread_info(p);
	extern unsigned int switch_to_pc;
	extern unsigned int ret_from_fork;
	struct reg_window *win;
	unsigned long pc, cwp;
	int i;

	for (i = GDB_G0; i < GDB_G6; i++)
		gdb_regs[i] = 0;
	gdb_regs[GDB_G6] = (unsigned long) t;
	gdb_regs[GDB_G7] = (unsigned long) p;
	for (i = GDB_O0; i < GDB_SP; i++)
		gdb_regs[i] = 0;
	gdb_regs[GDB_SP] = t->ksp;
	gdb_regs[GDB_O7] = 0;

	win = (struct reg_window *) (t->ksp + STACK_BIAS);
	for (i = 0; i < 8; i++)
		gdb_regs[GDB_L0 + i] = win->locals[i];
	for (i = 0; i < 8; i++)
		gdb_regs[GDB_I0 + i] = win->ins[i];

	for (i = GDB_F0; i <= GDB_F62; i++)
		gdb_regs[i] = 0;

	if (t->new_child)
		pc = (unsigned long) &ret_from_fork;
	else
		pc = (unsigned long) &switch_to_pc;

	gdb_regs[GDB_PC] = pc;
	gdb_regs[GDB_NPC] = pc + 4;

	cwp = __thread_flag_byte_ptr(t)[TI_FLAG_BYTE_CWP];

	gdb_regs[GDB_STATE] = (TSTATE_PRIV | TSTATE_IE | cwp);
	gdb_regs[GDB_FSR] = 0;
	gdb_regs[GDB_FPRS] = 0;
	gdb_regs[GDB_Y] = 0;
}

void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
	struct reg_window *win;
	int i;

	for (i = 0; i < 15; i++)
		regs->u_regs[UREG_G1 + i] = gdb_regs[GDB_G1 + i];

	/* If the TSTATE register is changing, we have to preserve
	 * the CWP field, otherwise window save/restore explodes.
	 */
	if (regs->tstate != gdb_regs[GDB_STATE]) {
		unsigned long cwp = regs->tstate & TSTATE_CWP;

		regs->tstate = (gdb_regs[GDB_STATE] & ~TSTATE_CWP) | cwp;
	}

	regs->tpc = gdb_regs[GDB_PC];
	regs->tnpc = gdb_regs[GDB_NPC];
	regs->y = gdb_regs[GDB_Y];

	win = (struct reg_window *) (regs->u_regs[UREG_FP] + STACK_BIAS);
	for (i = 0; i < 8; i++)
		win->locals[i] = gdb_regs[GDB_L0 + i];
	for (i = 0; i < 8; i++)
		win->ins[i] = gdb_regs[GDB_I0 + i];
}

#ifdef CONFIG_SMP
void __irq_entry smp_kgdb_capture_client(int irq, struct pt_regs *regs)
{
	unsigned long flags;

	__asm__ __volatile__("rdpr      %%pstate, %0\n\t"
			     "wrpr      %0, %1, %%pstate"
			     : "=r" (flags)
			     : "i" (PSTATE_IE));

	flushw_all();

	if (atomic_read(&kgdb_active) != -1)
		kgdb_nmicallback(raw_smp_processor_id(), regs);

	__asm__ __volatile__("wrpr	%0, 0, %%pstate"
			     : : "r" (flags));
}
#endif

int kgdb_arch_handle_exception(int e_vector, int signo, int err_code,
			       char *remcomInBuffer, char *remcomOutBuffer,
			       struct pt_regs *linux_regs)
{
	unsigned long addr;
	char *ptr;

	switch (remcomInBuffer[0]) {
	case 'c':
		/* try to read optional parameter, pc unchanged if no parm */
		ptr = &remcomInBuffer[1];
		if (kgdb_hex2long(&ptr, &addr)) {
			linux_regs->tpc = addr;
			linux_regs->tnpc = addr + 4;
		}
		/* fallthru */

	case 'D':
	case 'k':
		if (linux_regs->tpc == (unsigned long) arch_kgdb_breakpoint) {
			linux_regs->tpc = linux_regs->tnpc;
			linux_regs->tnpc += 4;
		}
		return 0;
	}
	return -1;
}

asmlinkage void kgdb_trap(unsigned long trap_level, struct pt_regs *regs)
{
	unsigned long flags;

	if (user_mode(regs)) {
		bad_trap(regs, trap_level);
		return;
	}

	flushw_all();

	local_irq_save(flags);
	kgdb_handle_exception(0x172, SIGTRAP, 0, regs);
	local_irq_restore(flags);
}

int kgdb_arch_init(void)
{
	return 0;
}

void kgdb_arch_exit(void)
{
}

void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip)
{
	regs->tpc = ip;
	regs->tnpc = regs->tpc + 4;
}

struct kgdb_arch arch_kgdb_ops = {
	/* Breakpoint instruction: ta 0x72 */
	.gdb_bpt_instr		= { 0x91, 0xd0, 0x20, 0x72 },
};
OpenPOWER on IntegriCloud