[net-next-2.6.git] / arch / arm / kernel / kgdb.c

/*
 * arch/arm/kernel/kgdb.c
 *
 * ARM KGDB support
 *
 * Copyright (c) 2002-2004 MontaVista Software, Inc
 * Copyright (c) 2008 Wind River Systems, Inc.
 *
 * Authors:  George Davis <davis_g@mvista.com>
 *           Deepak Saxena <dsaxena@plexity.net>
 */
#include <linux/irq.h>
#include <linux/kdebug.h>
#include <linux/kgdb.h>
#include <asm/traps.h>

struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
{
	{ "r0", 4, offsetof(struct pt_regs, ARM_r0)},
	{ "r1", 4, offsetof(struct pt_regs, ARM_r1)},
	{ "r2", 4, offsetof(struct pt_regs, ARM_r2)},
	{ "r3", 4, offsetof(struct pt_regs, ARM_r3)},
	{ "r4", 4, offsetof(struct pt_regs, ARM_r4)},
	{ "r5", 4, offsetof(struct pt_regs, ARM_r5)},
	{ "r6", 4, offsetof(struct pt_regs, ARM_r6)},
	{ "r7", 4, offsetof(struct pt_regs, ARM_r7)},
	{ "r8", 4, offsetof(struct pt_regs, ARM_r8)},
	{ "r9", 4, offsetof(struct pt_regs, ARM_r9)},
	{ "r10", 4, offsetof(struct pt_regs, ARM_r10)},
	{ "fp", 4, offsetof(struct pt_regs, ARM_fp)},
	{ "ip", 4, offsetof(struct pt_regs, ARM_ip)},
	{ "sp", 4, offsetof(struct pt_regs, ARM_sp)},
	{ "lr", 4, offsetof(struct pt_regs, ARM_lr)},
	{ "pc", 4, offsetof(struct pt_regs, ARM_pc)},
	{ "f0", 12, -1 },
	{ "f1", 12, -1 },
	{ "f2", 12, -1 },
	{ "f3", 12, -1 },
	{ "f4", 12, -1 },
	{ "f5", 12, -1 },
	{ "f6", 12, -1 },
	{ "f7", 12, -1 },
	{ "fps", 4, -1 },
	{ "cpsr", 4, offsetof(struct pt_regs, ARM_cpsr)},
};

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

	if (dbg_reg_def[regno].offset != -1)
		memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
		       dbg_reg_def[regno].size);
	else
		memset(mem, 0, dbg_reg_def[regno].size);
	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;

	if (dbg_reg_def[regno].offset != -1)
		memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
		       dbg_reg_def[regno].size);
	return 0;
}

void
sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *task)
{
	struct pt_regs *thread_regs;
	int regno;

	/* Just making sure... */
	if (task == NULL)
		return;

	/* Initialize to zero */
	for (regno = 0; regno < GDB_MAX_REGS; regno++)
		gdb_regs[regno] = 0;

	/* Otherwise, we have only some registers from switch_to() */
	thread_regs		= task_pt_regs(task);
	gdb_regs[_R0]		= thread_regs->ARM_r0;
	gdb_regs[_R1]		= thread_regs->ARM_r1;
	gdb_regs[_R2]		= thread_regs->ARM_r2;
	gdb_regs[_R3]		= thread_regs->ARM_r3;
	gdb_regs[_R4]		= thread_regs->ARM_r4;
	gdb_regs[_R5]		= thread_regs->ARM_r5;
	gdb_regs[_R6]		= thread_regs->ARM_r6;
	gdb_regs[_R7]		= thread_regs->ARM_r7;
	gdb_regs[_R8]		= thread_regs->ARM_r8;
	gdb_regs[_R9]		= thread_regs->ARM_r9;
	gdb_regs[_R10]		= thread_regs->ARM_r10;
	gdb_regs[_FP]		= thread_regs->ARM_fp;
	gdb_regs[_IP]		= thread_regs->ARM_ip;
	gdb_regs[_SPT]		= thread_regs->ARM_sp;
	gdb_regs[_LR]		= thread_regs->ARM_lr;
	gdb_regs[_PC]		= thread_regs->ARM_pc;
	gdb_regs[_CPSR]		= thread_regs->ARM_cpsr;
}

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

static int compiled_break;

int kgdb_arch_handle_exception(int exception_vector, int signo,
			       int err_code, char *remcom_in_buffer,
			       char *remcom_out_buffer,
			       struct pt_regs *linux_regs)
{
	unsigned long addr;
	char *ptr;

	switch (remcom_in_buffer[0]) {
	case 'D':
	case 'k':
	case 'c':
		/*
		 * Try to read optional parameter, pc unchanged if no parm.
		 * If this was a compiled breakpoint, we need to move
		 * to the next instruction or we will just breakpoint
		 * over and over again.
		 */
		ptr = &remcom_in_buffer[1];
		if (kgdb_hex2long(&ptr, &addr))
			linux_regs->ARM_pc = addr;
		else if (compiled_break == 1)
			linux_regs->ARM_pc += 4;

		compiled_break = 0;

		return 0;
	}

	return -1;
}

static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
{
	kgdb_handle_exception(1, SIGTRAP, 0, regs);

	return 0;
}

static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
{
	compiled_break = 1;
	kgdb_handle_exception(1, SIGTRAP, 0, regs);

	return 0;
}

static struct undef_hook kgdb_brkpt_hook = {
	.instr_mask		= 0xffffffff,
	.instr_val		= KGDB_BREAKINST,
	.fn			= kgdb_brk_fn
};

static struct undef_hook kgdb_compiled_brkpt_hook = {
	.instr_mask		= 0xffffffff,
	.instr_val		= KGDB_COMPILED_BREAK,
	.fn			= kgdb_compiled_brk_fn
};

static void kgdb_call_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(kgdb_call_nmi_hook, NULL, 0);
       local_irq_disable();
}

static int __kgdb_notify(struct die_args *args, unsigned long cmd)
{
	struct pt_regs *regs = args->regs;

	if (kgdb_handle_exception(1, args->signr, cmd, 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,
	.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)
{
	int ret = register_die_notifier(&kgdb_notifier);

	if (ret != 0)
		return ret;

	register_undef_hook(&kgdb_brkpt_hook);
	register_undef_hook(&kgdb_compiled_brkpt_hook);

	return 0;
}

/**
 *	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_undef_hook(&kgdb_brkpt_hook);
	unregister_undef_hook(&kgdb_compiled_brkpt_hook);
	unregister_die_notifier(&kgdb_notifier);
}

/*
 * Register our undef instruction hooks with ARM undef core.
 * We regsiter a hook specifically looking for the KGB break inst
 * and we handle the normal undef case within the do_undefinstr
 * handler.
 */
struct kgdb_arch arch_kgdb_ops = {
#ifndef __ARMEB__
	.gdb_bpt_instr		= {0xfe, 0xde, 0xff, 0xe7}
#else /* ! __ARMEB__ */
	.gdb_bpt_instr		= {0xe7, 0xff, 0xde, 0xfe}
#endif
};
Commit	Line	Data
5cbad0eb JW	1	/*
	2	* arch/arm/kernel/kgdb.c
	3	*
	4	* ARM KGDB support
	5	*
	6	* Copyright (c) 2002-2004 MontaVista Software, Inc
	7	* Copyright (c) 2008 Wind River Systems, Inc.
	8	*
	9	* Authors: George Davis <davis_g@mvista.com>
	10	* Deepak Saxena <dsaxena@plexity.net>
	11	*/
5d8614cc	12	#include <linux/irq.h>
62a0309c	13	#include <linux/kdebug.h>
5cbad0eb JW	14	#include <linux/kgdb.h>
	15	#include <asm/traps.h>
	16
22eeef4b	17	struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
5cbad0eb	18	{
22eeef4b JW	19	{ "r0", 4, offsetof(struct pt_regs, ARM_r0)},
	20	{ "r1", 4, offsetof(struct pt_regs, ARM_r1)},
	21	{ "r2", 4, offsetof(struct pt_regs, ARM_r2)},
	22	{ "r3", 4, offsetof(struct pt_regs, ARM_r3)},
	23	{ "r4", 4, offsetof(struct pt_regs, ARM_r4)},
	24	{ "r5", 4, offsetof(struct pt_regs, ARM_r5)},
	25	{ "r6", 4, offsetof(struct pt_regs, ARM_r6)},
	26	{ "r7", 4, offsetof(struct pt_regs, ARM_r7)},
	27	{ "r8", 4, offsetof(struct pt_regs, ARM_r8)},
	28	{ "r9", 4, offsetof(struct pt_regs, ARM_r9)},
	29	{ "r10", 4, offsetof(struct pt_regs, ARM_r10)},
	30	{ "fp", 4, offsetof(struct pt_regs, ARM_fp)},
	31	{ "ip", 4, offsetof(struct pt_regs, ARM_ip)},
	32	{ "sp", 4, offsetof(struct pt_regs, ARM_sp)},
	33	{ "lr", 4, offsetof(struct pt_regs, ARM_lr)},
	34	{ "pc", 4, offsetof(struct pt_regs, ARM_pc)},
	35	{ "f0", 12, -1 },
	36	{ "f1", 12, -1 },
	37	{ "f2", 12, -1 },
	38	{ "f3", 12, -1 },
	39	{ "f4", 12, -1 },
	40	{ "f5", 12, -1 },
	41	{ "f6", 12, -1 },
	42	{ "f7", 12, -1 },
	43	{ "fps", 4, -1 },
	44	{ "cpsr", 4, offsetof(struct pt_regs, ARM_cpsr)},
	45	};
5cbad0eb	46
22eeef4b JW	47	char dbg_get_reg(int regno, void mem, struct pt_regs *regs)
	48	{
	49	if (regno >= DBG_MAX_REG_NUM \|\| regno < 0)
	50	return NULL;
5cbad0eb	51
22eeef4b JW	52	if (dbg_reg_def[regno].offset != -1)
	53	memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
	54	dbg_reg_def[regno].size);
	55	else
	56	memset(mem, 0, dbg_reg_def[regno].size);
	57	return dbg_reg_def[regno].name;
5cbad0eb JW	58	}
5cbad0eb JW	59
22eeef4b	60	int dbg_set_reg(int regno, void mem, struct pt_regs regs)
5cbad0eb	61	{
22eeef4b JW	62	if (regno >= DBG_MAX_REG_NUM \|\| regno < 0)
	63	return -EINVAL;
	64
	65	if (dbg_reg_def[regno].offset != -1)
	66	memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
	67	dbg_reg_def[regno].size);
	68	return 0;
5cbad0eb JW	69	}
	70
	71	void
	72	sleeping_thread_to_gdb_regs(unsigned long gdb_regs, struct task_struct task)
	73	{
	74	struct pt_regs *thread_regs;
	75	int regno;
	76
	77	/* Just making sure... */
	78	if (task == NULL)
	79	return;
	80
	81	/* Initialize to zero */
834b2964	82	for (regno = 0; regno < GDB_MAX_REGS; regno++)
5cbad0eb JW	83	gdb_regs[regno] = 0;
	84
	85	/* Otherwise, we have only some registers from switch_to() */
	86	thread_regs = task_pt_regs(task);
	87	gdb_regs[_R0] = thread_regs->ARM_r0;
	88	gdb_regs[_R1] = thread_regs->ARM_r1;
	89	gdb_regs[_R2] = thread_regs->ARM_r2;
	90	gdb_regs[_R3] = thread_regs->ARM_r3;
	91	gdb_regs[_R4] = thread_regs->ARM_r4;
	92	gdb_regs[_R5] = thread_regs->ARM_r5;
	93	gdb_regs[_R6] = thread_regs->ARM_r6;
	94	gdb_regs[_R7] = thread_regs->ARM_r7;
	95	gdb_regs[_R8] = thread_regs->ARM_r8;
	96	gdb_regs[_R9] = thread_regs->ARM_r9;
	97	gdb_regs[_R10] = thread_regs->ARM_r10;
	98	gdb_regs[_FP] = thread_regs->ARM_fp;
	99	gdb_regs[_IP] = thread_regs->ARM_ip;
	100	gdb_regs[_SPT] = thread_regs->ARM_sp;
	101	gdb_regs[_LR] = thread_regs->ARM_lr;
	102	gdb_regs[_PC] = thread_regs->ARM_pc;
	103	gdb_regs[_CPSR] = thread_regs->ARM_cpsr;
	104	}
	105
dcc78711 JW	106	void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
	107	{
	108	regs->ARM_pc = pc;
	109	}
	110
5cbad0eb JW	111	static int compiled_break;
	112
	113	int kgdb_arch_handle_exception(int exception_vector, int signo,
	114	int err_code, char *remcom_in_buffer,
	115	char *remcom_out_buffer,
	116	struct pt_regs *linux_regs)
	117	{
	118	unsigned long addr;
	119	char *ptr;
	120
	121	switch (remcom_in_buffer[0]) {
	122	case 'D':
	123	case 'k':
	124	case 'c':
5cbad0eb JW	125	/*
	126	* Try to read optional parameter, pc unchanged if no parm.
	127	* If this was a compiled breakpoint, we need to move
	128	* to the next instruction or we will just breakpoint
	129	* over and over again.
	130	*/
	131	ptr = &remcom_in_buffer[1];
	132	if (kgdb_hex2long(&ptr, &addr))
	133	linux_regs->ARM_pc = addr;
	134	else if (compiled_break == 1)
	135	linux_regs->ARM_pc += 4;
	136
	137	compiled_break = 0;
	138
	139	return 0;
	140	}
	141
	142	return -1;
	143	}
	144
	145	static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
	146	{
	147	kgdb_handle_exception(1, SIGTRAP, 0, regs);
	148
	149	return 0;
	150	}
	151
	152	static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
	153	{
	154	compiled_break = 1;
	155	kgdb_handle_exception(1, SIGTRAP, 0, regs);
	156
	157	return 0;
	158	}
	159
	160	static struct undef_hook kgdb_brkpt_hook = {
	161	.instr_mask = 0xffffffff,
	162	.instr_val = KGDB_BREAKINST,
	163	.fn = kgdb_brk_fn
	164	};
	165
	166	static struct undef_hook kgdb_compiled_brkpt_hook = {
	167	.instr_mask = 0xffffffff,
	168	.instr_val = KGDB_COMPILED_BREAK,
	169	.fn = kgdb_compiled_brk_fn
	170	};
	171
5d8614cc WD	172	static void kgdb_call_nmi_hook(void *ignored)
	173	{
	174	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
	175	}
	176
	177	void kgdb_roundup_cpus(unsigned long flags)
	178	{
	179	local_irq_enable();
	180	smp_call_function(kgdb_call_nmi_hook, NULL, 0);
	181	local_irq_disable();
	182	}
	183
62a0309c JW	184	static int __kgdb_notify(struct die_args *args, unsigned long cmd)
	185	{
	186	struct pt_regs *regs = args->regs;
	187
	188	if (kgdb_handle_exception(1, args->signr, cmd, regs))
	189	return NOTIFY_DONE;
	190	return NOTIFY_STOP;
	191	}
	192	static int
	193	kgdb_notify(struct notifier_block self, unsigned long cmd, void ptr)
	194	{
	195	unsigned long flags;
	196	int ret;
	197
	198	local_irq_save(flags);
	199	ret = __kgdb_notify(ptr, cmd);
	200	local_irq_restore(flags);
	201
	202	return ret;
	203	}
	204
	205	static struct notifier_block kgdb_notifier = {
	206	.notifier_call = kgdb_notify,
	207	.priority = -INT_MAX,
	208	};
	209
	210
5cbad0eb JW	211	/**
	212	* kgdb_arch_init - Perform any architecture specific initalization.
	213	*
	214	* This function will handle the initalization of any architecture
	215	* specific callbacks.
	216	*/
	217	int kgdb_arch_init(void)
	218	{
62a0309c JW	219	int ret = register_die_notifier(&kgdb_notifier);
	220
	221	if (ret != 0)
	222	return ret;
	223
5cbad0eb JW	224	register_undef_hook(&kgdb_brkpt_hook);
	225	register_undef_hook(&kgdb_compiled_brkpt_hook);
	226
	227	return 0;
	228	}
	229
	230	/**
	231	* kgdb_arch_exit - Perform any architecture specific uninitalization.
	232	*
	233	* This function will handle the uninitalization of any architecture
	234	* specific callbacks, for dynamic registration and unregistration.
	235	*/
	236	void kgdb_arch_exit(void)
	237	{
	238	unregister_undef_hook(&kgdb_brkpt_hook);
	239	unregister_undef_hook(&kgdb_compiled_brkpt_hook);
62a0309c	240	unregister_die_notifier(&kgdb_notifier);
5cbad0eb JW	241	}
	242
	243	/*
	244	* Register our undef instruction hooks with ARM undef core.
	245	* We regsiter a hook specifically looking for the KGB break inst
	246	* and we handle the normal undef case within the do_undefinstr
	247	* handler.
	248	*/
	249	struct kgdb_arch arch_kgdb_ops = {
	250	#ifndef __ARMEB__
	251	.gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7}
	252	#else /* ! __ARMEB__ */
	253	.gdb_bpt_instr = {0xe7, 0xff, 0xde, 0xfe}
	254	#endif
	255	};