[mirror_ubuntu-artful-kernel.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/kgdb.h>
#include <asm/traps.h>

/* Make a local copy of the registers passed into the handler (bletch) */
void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
{
	int regno;

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

	gdb_regs[_R0]		= kernel_regs->ARM_r0;
	gdb_regs[_R1]		= kernel_regs->ARM_r1;
	gdb_regs[_R2]		= kernel_regs->ARM_r2;
	gdb_regs[_R3]		= kernel_regs->ARM_r3;
	gdb_regs[_R4]		= kernel_regs->ARM_r4;
	gdb_regs[_R5]		= kernel_regs->ARM_r5;
	gdb_regs[_R6]		= kernel_regs->ARM_r6;
	gdb_regs[_R7]		= kernel_regs->ARM_r7;
	gdb_regs[_R8]		= kernel_regs->ARM_r8;
	gdb_regs[_R9]		= kernel_regs->ARM_r9;
	gdb_regs[_R10]		= kernel_regs->ARM_r10;
	gdb_regs[_FP]		= kernel_regs->ARM_fp;
	gdb_regs[_IP]		= kernel_regs->ARM_ip;
	gdb_regs[_SPT]		= kernel_regs->ARM_sp;
	gdb_regs[_LR]		= kernel_regs->ARM_lr;
	gdb_regs[_PC]		= kernel_regs->ARM_pc;
	gdb_regs[_CPSR]		= kernel_regs->ARM_cpsr;
}

/* Copy local gdb registers back to kgdb regs, for later copy to kernel */
void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *kernel_regs)
{
	kernel_regs->ARM_r0	= gdb_regs[_R0];
	kernel_regs->ARM_r1	= gdb_regs[_R1];
	kernel_regs->ARM_r2	= gdb_regs[_R2];
	kernel_regs->ARM_r3	= gdb_regs[_R3];
	kernel_regs->ARM_r4	= gdb_regs[_R4];
	kernel_regs->ARM_r5	= gdb_regs[_R5];
	kernel_regs->ARM_r6	= gdb_regs[_R6];
	kernel_regs->ARM_r7	= gdb_regs[_R7];
	kernel_regs->ARM_r8	= gdb_regs[_R8];
	kernel_regs->ARM_r9	= gdb_regs[_R9];
	kernel_regs->ARM_r10	= gdb_regs[_R10];
	kernel_regs->ARM_fp	= gdb_regs[_FP];
	kernel_regs->ARM_ip	= gdb_regs[_IP];
	kernel_regs->ARM_sp	= gdb_regs[_SPT];
	kernel_regs->ARM_lr	= gdb_regs[_LR];
	kernel_regs->ARM_pc	= gdb_regs[_PC];
	kernel_regs->ARM_cpsr	= gdb_regs[_CPSR];
}

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;
}

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
};

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

/*
 * 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	*/
	12	#include <linux/kgdb.h>
	13	#include <asm/traps.h>
	14
	15	/* Make a local copy of the registers passed into the handler (bletch) */
	16	void pt_regs_to_gdb_regs(unsigned long gdb_regs, struct pt_regs kernel_regs)
	17	{
	18	int regno;
	19
	20	/* Initialize all to zero. */
	21	for (regno = 0; regno < GDB_MAX_REGS; regno++)
	22	gdb_regs[regno] = 0;
	23
	24	gdb_regs[_R0] = kernel_regs->ARM_r0;
	25	gdb_regs[_R1] = kernel_regs->ARM_r1;
	26	gdb_regs[_R2] = kernel_regs->ARM_r2;
	27	gdb_regs[_R3] = kernel_regs->ARM_r3;
	28	gdb_regs[_R4] = kernel_regs->ARM_r4;
	29	gdb_regs[_R5] = kernel_regs->ARM_r5;
	30	gdb_regs[_R6] = kernel_regs->ARM_r6;
	31	gdb_regs[_R7] = kernel_regs->ARM_r7;
	32	gdb_regs[_R8] = kernel_regs->ARM_r8;
	33	gdb_regs[_R9] = kernel_regs->ARM_r9;
	34	gdb_regs[_R10] = kernel_regs->ARM_r10;
	35	gdb_regs[_FP] = kernel_regs->ARM_fp;
	36	gdb_regs[_IP] = kernel_regs->ARM_ip;
	37	gdb_regs[_SPT] = kernel_regs->ARM_sp;
	38	gdb_regs[_LR] = kernel_regs->ARM_lr;
	39	gdb_regs[_PC] = kernel_regs->ARM_pc;
	40	gdb_regs[_CPSR] = kernel_regs->ARM_cpsr;
	41	}
	42
	43	/* Copy local gdb registers back to kgdb regs, for later copy to kernel */
	44	void gdb_regs_to_pt_regs(unsigned long gdb_regs, struct pt_regs kernel_regs)
	45	{
	46	kernel_regs->ARM_r0 = gdb_regs[_R0];
	47	kernel_regs->ARM_r1 = gdb_regs[_R1];
	48	kernel_regs->ARM_r2 = gdb_regs[_R2];
	49	kernel_regs->ARM_r3 = gdb_regs[_R3];
	50	kernel_regs->ARM_r4 = gdb_regs[_R4];
	51	kernel_regs->ARM_r5 = gdb_regs[_R5];
	52	kernel_regs->ARM_r6 = gdb_regs[_R6];
	53	kernel_regs->ARM_r7 = gdb_regs[_R7];
	54	kernel_regs->ARM_r8 = gdb_regs[_R8];
	55	kernel_regs->ARM_r9 = gdb_regs[_R9];
	56	kernel_regs->ARM_r10 = gdb_regs[_R10];
	57	kernel_regs->ARM_fp = gdb_regs[_FP];
	58	kernel_regs->ARM_ip = gdb_regs[_IP];
	59	kernel_regs->ARM_sp = gdb_regs[_SPT];
	60	kernel_regs->ARM_lr = gdb_regs[_LR];
	61	kernel_regs->ARM_pc = gdb_regs[_PC];
	62	kernel_regs->ARM_cpsr = gdb_regs[_CPSR];
	63	}
	64
65	void
66	sleeping_thread_to_gdb_regs(unsigned long gdb_regs, struct task_struct task)
67	{
68	struct pt_regs *thread_regs;
69	int regno;
70
71	/* Just making sure... */
72	if (task == NULL)
73	return;
74
75	/* Initialize to zero */
76	for (regno = 0; regno < GDB_MAX_REGS; regno++)
77	gdb_regs[regno] = 0;
78
79	/* Otherwise, we have only some registers from switch_to() */
80	thread_regs = task_pt_regs(task);
81	gdb_regs[_R0] = thread_regs->ARM_r0;
82	gdb_regs[_R1] = thread_regs->ARM_r1;
83	gdb_regs[_R2] = thread_regs->ARM_r2;
84	gdb_regs[_R3] = thread_regs->ARM_r3;
85	gdb_regs[_R4] = thread_regs->ARM_r4;
86	gdb_regs[_R5] = thread_regs->ARM_r5;
87	gdb_regs[_R6] = thread_regs->ARM_r6;
88	gdb_regs[_R7] = thread_regs->ARM_r7;
89	gdb_regs[_R8] = thread_regs->ARM_r8;
90	gdb_regs[_R9] = thread_regs->ARM_r9;
91	gdb_regs[_R10] = thread_regs->ARM_r10;
92	gdb_regs[_FP] = thread_regs->ARM_fp;
93	gdb_regs[_IP] = thread_regs->ARM_ip;
94	gdb_regs[_SPT] = thread_regs->ARM_sp;
95	gdb_regs[_LR] = thread_regs->ARM_lr;
96	gdb_regs[_PC] = thread_regs->ARM_pc;
97	gdb_regs[_CPSR] = thread_regs->ARM_cpsr;
98	}
99
100	static int compiled_break;
101
102	int kgdb_arch_handle_exception(int exception_vector, int signo,
103	int err_code, char *remcom_in_buffer,
104	char *remcom_out_buffer,
105	struct pt_regs *linux_regs)
106	{
107	unsigned long addr;
108	char *ptr;
109
110	switch (remcom_in_buffer[0]) {
111	case 'D':
112	case 'k':
113	case 'c':
5cbad0eb JW	114	/*
	115	* Try to read optional parameter, pc unchanged if no parm.
	116	* If this was a compiled breakpoint, we need to move
	117	* to the next instruction or we will just breakpoint
	118	* over and over again.
	119	*/
	120	ptr = &remcom_in_buffer[1];
	121	if (kgdb_hex2long(&ptr, &addr))
	122	linux_regs->ARM_pc = addr;
	123	else if (compiled_break == 1)
	124	linux_regs->ARM_pc += 4;
	125
	126	compiled_break = 0;
	127
	128	return 0;
	129	}
	130
	131	return -1;
	132	}
	133
	134	static int kgdb_brk_fn(struct pt_regs *regs, unsigned int instr)
	135	{
	136	kgdb_handle_exception(1, SIGTRAP, 0, regs);
	137
	138	return 0;
	139	}
	140
	141	static int kgdb_compiled_brk_fn(struct pt_regs *regs, unsigned int instr)
	142	{
	143	compiled_break = 1;
	144	kgdb_handle_exception(1, SIGTRAP, 0, regs);
	145
	146	return 0;
	147	}
	148
	149	static struct undef_hook kgdb_brkpt_hook = {
	150	.instr_mask = 0xffffffff,
	151	.instr_val = KGDB_BREAKINST,
	152	.fn = kgdb_brk_fn
	153	};
	154
	155	static struct undef_hook kgdb_compiled_brkpt_hook = {
	156	.instr_mask = 0xffffffff,
	157	.instr_val = KGDB_COMPILED_BREAK,
	158	.fn = kgdb_compiled_brk_fn
	159	};
	160
	161	/**
	162	* kgdb_arch_init - Perform any architecture specific initalization.
	163	*
	164	* This function will handle the initalization of any architecture
	165	* specific callbacks.
	166	*/
	167	int kgdb_arch_init(void)
	168	{
	169	register_undef_hook(&kgdb_brkpt_hook);
	170	register_undef_hook(&kgdb_compiled_brkpt_hook);
	171
	172	return 0;
	173	}
	174
	175	/**
	176	* kgdb_arch_exit - Perform any architecture specific uninitalization.
	177	*
178	* This function will handle the uninitalization of any architecture
179	* specific callbacks, for dynamic registration and unregistration.
180	*/
181	void kgdb_arch_exit(void)
182	{
183	unregister_undef_hook(&kgdb_brkpt_hook);
184	unregister_undef_hook(&kgdb_compiled_brkpt_hook);
185	}
186
187	/*
188	* Register our undef instruction hooks with ARM undef core.
189	* We regsiter a hook specifically looking for the KGB break inst
190	* and we handle the normal undef case within the do_undefinstr
191	* handler.
192	*/
193	struct kgdb_arch arch_kgdb_ops = {
194	#ifndef __ARMEB__
195	.gdb_bpt_instr = {0xfe, 0xde, 0xff, 0xe7}
196	#else /* ! __ARMEB__ */
197	.gdb_bpt_instr = {0xe7, 0xff, 0xde, 0xfe}
198	#endif
199	};