summaryrefslogtreecommitdiffstats
path: root/arch/hexagon/kernel/kgdb.c
blob: 19f9e6ca5e337e7f66451dd9270d78d9cd264501 (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
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
/*
 * arch/hexagon/kernel/kgdb.c - Hexagon KGDB Support
 *
 * Copyright (c) 2011, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

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

/* All registers are 4 bytes, for now */
#define GDB_SIZEOF_REG 4

/* The register names are used during printing of the regs;
 * Keep these at three letters to pretty-print. */
struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = {
	{ " r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, r00)},
	{ " r1", GDB_SIZEOF_REG, offsetof(struct pt_regs, r01)},
	{ " r2", GDB_SIZEOF_REG, offsetof(struct pt_regs, r02)},
	{ " r3", GDB_SIZEOF_REG, offsetof(struct pt_regs, r03)},
	{ " r4", GDB_SIZEOF_REG, offsetof(struct pt_regs, r04)},
	{ " r5", GDB_SIZEOF_REG, offsetof(struct pt_regs, r05)},
	{ " r6", GDB_SIZEOF_REG, offsetof(struct pt_regs, r06)},
	{ " r7", GDB_SIZEOF_REG, offsetof(struct pt_regs, r07)},
	{ " r8", GDB_SIZEOF_REG, offsetof(struct pt_regs, r08)},
	{ " r9", GDB_SIZEOF_REG, offsetof(struct pt_regs, r09)},
	{ "r10", GDB_SIZEOF_REG, offsetof(struct pt_regs, r10)},
	{ "r11", GDB_SIZEOF_REG, offsetof(struct pt_regs, r11)},
	{ "r12", GDB_SIZEOF_REG, offsetof(struct pt_regs, r12)},
	{ "r13", GDB_SIZEOF_REG, offsetof(struct pt_regs, r13)},
	{ "r14", GDB_SIZEOF_REG, offsetof(struct pt_regs, r14)},
	{ "r15", GDB_SIZEOF_REG, offsetof(struct pt_regs, r15)},
	{ "r16", GDB_SIZEOF_REG, offsetof(struct pt_regs, r16)},
	{ "r17", GDB_SIZEOF_REG, offsetof(struct pt_regs, r17)},
	{ "r18", GDB_SIZEOF_REG, offsetof(struct pt_regs, r18)},
	{ "r19", GDB_SIZEOF_REG, offsetof(struct pt_regs, r19)},
	{ "r20", GDB_SIZEOF_REG, offsetof(struct pt_regs, r20)},
	{ "r21", GDB_SIZEOF_REG, offsetof(struct pt_regs, r21)},
	{ "r22", GDB_SIZEOF_REG, offsetof(struct pt_regs, r22)},
	{ "r23", GDB_SIZEOF_REG, offsetof(struct pt_regs, r23)},
	{ "r24", GDB_SIZEOF_REG, offsetof(struct pt_regs, r24)},
	{ "r25", GDB_SIZEOF_REG, offsetof(struct pt_regs, r25)},
	{ "r26", GDB_SIZEOF_REG, offsetof(struct pt_regs, r26)},
	{ "r27", GDB_SIZEOF_REG, offsetof(struct pt_regs, r27)},
	{ "r28", GDB_SIZEOF_REG, offsetof(struct pt_regs, r28)},
	{ "r29", GDB_SIZEOF_REG, offsetof(struct pt_regs, r29)},
	{ "r30", GDB_SIZEOF_REG, offsetof(struct pt_regs, r30)},
	{ "r31", GDB_SIZEOF_REG, offsetof(struct pt_regs, r31)},

	{ "usr", GDB_SIZEOF_REG, offsetof(struct pt_regs, usr)},
	{ "preds", GDB_SIZEOF_REG, offsetof(struct pt_regs, preds)},
	{ " m0", GDB_SIZEOF_REG, offsetof(struct pt_regs, m0)},
	{ " m1", GDB_SIZEOF_REG, offsetof(struct pt_regs, m1)},
	{ "sa0", GDB_SIZEOF_REG, offsetof(struct pt_regs, sa0)},
	{ "sa1", GDB_SIZEOF_REG, offsetof(struct pt_regs, sa1)},
	{ "lc0", GDB_SIZEOF_REG, offsetof(struct pt_regs, lc0)},
	{ "lc1", GDB_SIZEOF_REG, offsetof(struct pt_regs, lc1)},
	{ " gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, gp)},
	{ "ugp", GDB_SIZEOF_REG, offsetof(struct pt_regs, ugp)},
	{ "cs0", GDB_SIZEOF_REG, offsetof(struct pt_regs, cs0)},
	{ "cs1", GDB_SIZEOF_REG, offsetof(struct pt_regs, cs1)},
	{ "psp", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmpsp)},
	{ "elr", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmel)},
	{ "est", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmest)},
	{ "badva", GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmbadva)},
	{ "restart_r0", GDB_SIZEOF_REG, offsetof(struct pt_regs, restart_r0)},
	{ "syscall_nr", GDB_SIZEOF_REG, offsetof(struct pt_regs, syscall_nr)},
};

struct kgdb_arch arch_kgdb_ops = {
	/* trap0(#0xDB) 0x0cdb0054 */
	.gdb_bpt_instr = {0x54, 0x00, 0xdb, 0x0c},
};

char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
{
	if (regno >= DBG_MAX_REG_NUM || regno < 0)
		return NULL;

	*((unsigned long *) mem) = *((unsigned long *) ((void *)regs +
		dbg_reg_def[regno].offset));

	return dbg_reg_def[regno].name;
}

int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
{
	if (regno >= DBG_MAX_REG_NUM || regno < 0)
		return -EINVAL;

	*((unsigned long *) ((void *)regs + dbg_reg_def[regno].offset)) =
		*((unsigned long *) mem);

	return 0;
}

void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
{
	instruction_pointer(regs) = pc;
}

#ifdef CONFIG_SMP

/**
 * kgdb_roundup_cpus - Get other CPUs into a holding pattern
 * @flags: Current IRQ state
 *
 * On SMP systems, we need to get the attention of the other CPUs
 * and get them be in a known state.  This should do what is needed
 * to get the other CPUs to call kgdb_wait(). Note that on some arches,
 * the NMI approach is not used for rounding up all the CPUs. For example,
 * in case of MIPS, smp_call_function() is used to roundup CPUs. In
 * this case, we have to make sure that interrupts are enabled before
 * calling smp_call_function(). The argument to this function is
 * the flags that will be used when restoring the interrupts. There is
 * local_irq_save() call before kgdb_roundup_cpus().
 *
 * On non-SMP systems, this is not called.
 */

static void hexagon_kgdb_nmi_hook(void *ignored)
{
	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
}

void kgdb_roundup_cpus(unsigned long flags)
{
	local_irq_enable();
	smp_call_function(hexagon_kgdb_nmi_hook, NULL, 0);
	local_irq_disable();
}
#endif


/*  Not yet working  */
void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs,
				 struct task_struct *task)
{
	struct pt_regs *thread_regs;

	if (task == NULL)
		return;

	/* Initialize to zero */
	memset(gdb_regs, 0, NUMREGBYTES);

	/* Otherwise, we have only some registers from switch_to() */
	thread_regs = task_pt_regs(task);
	gdb_regs[0] = thread_regs->r00;
}

/**
 * kgdb_arch_handle_exception - Handle architecture specific GDB packets.
 * @vector: The error vector of the exception that happened.
 * @signo: The signal number of the exception that happened.
 * @err_code: The error code of the exception that happened.
 * @remcom_in_buffer: The buffer of the packet we have read.
 * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into.
 * @regs: The &struct pt_regs of the current process.
 *
 * This function MUST handle the 'c' and 's' command packets,
 * as well packets to set / remove a hardware breakpoint, if used.
 * If there are additional packets which the hardware needs to handle,
 * they are handled here.  The code should return -1 if it wants to
 * process more packets, and a %0 or %1 if it wants to exit from the
 * kgdb callback.
 *
 * Not yet working.
 */
int kgdb_arch_handle_exception(int vector, int signo, int err_code,
			       char *remcom_in_buffer, char *remcom_out_buffer,
			       struct pt_regs *linux_regs)
{
	switch (remcom_in_buffer[0]) {
	case 's':
	case 'c':
		return 0;
	}
	/* Stay in the debugger. */
	return -1;
}

static int __kgdb_notify(struct die_args *args, unsigned long cmd)
{
	/* cpu roundup */
	if (atomic_read(&kgdb_active) != -1) {
		kgdb_nmicallback(smp_processor_id(), args->regs);
		return NOTIFY_STOP;
	}

	if (user_mode(args->regs))
		return NOTIFY_DONE;

	if (kgdb_handle_exception(args->trapnr & 0xff, args->signr, args->err,
				    args->regs))
		return NOTIFY_DONE;

	return NOTIFY_STOP;
}

static int
kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr)
{
	unsigned long flags;
	int ret;

	local_irq_save(flags);
	ret = __kgdb_notify(ptr, cmd);
	local_irq_restore(flags);

	return ret;
}

static struct notifier_block kgdb_notifier = {
	.notifier_call = kgdb_notify,

	/*
	 * Lowest-prio notifier priority, we want to be notified last:
	 */
	.priority = -INT_MAX,
};

/**
 * kgdb_arch_init - Perform any architecture specific initalization.
 *
 * This function will handle the initalization of any architecture
 * specific callbacks.
 */
int kgdb_arch_init(void)
{
	return register_die_notifier(&kgdb_notifier);
}

/**
 * kgdb_arch_exit - Perform any architecture specific uninitalization.
 *
 * This function will handle the uninitalization of any architecture
 * specific callbacks, for dynamic registration and unregistration.
 */
void kgdb_arch_exit(void)
{
	unregister_die_notifier(&kgdb_notifier);
}