[linux.git] / arch / mips / kernel / kgdb.c

/*
 *  Originally written by Glenn Engel, Lake Stevens Instrument Division
 *
 *  Contributed by HP Systems
 *
 *  Modified for Linux/MIPS (and MIPS in general) by Andreas Busse
 *  Send complaints, suggestions etc. to <[email protected]>
 *
 *  Copyright (C) 1995 Andreas Busse
 *
 *  Copyright (C) 2003 MontaVista Software Inc.
 *  Author: Jun Sun, [email protected] or [email protected]
 *
 *  Copyright (C) 2004-2005 MontaVista Software Inc.
 *  Author: Manish Lachwani, [email protected] or [email protected]
 *
 *  Copyright (C) 2007-2008 Wind River Systems, Inc.
 *  Author/Maintainer: Jason Wessel, [email protected]
 *
 *  This file is licensed under the terms of the GNU General Public License
 *  version 2. This program is licensed "as is" without any warranty of any
 *  kind, whether express or implied.
 */

#include <linux/ptrace.h>		/* for linux pt_regs struct */
#include <linux/kgdb.h>
#include <linux/kdebug.h>
#include <linux/sched.h>
#include <linux/smp.h>
#include <asm/inst.h>
#include <asm/fpu.h>
#include <asm/cacheflush.h>
#include <asm/processor.h>
#include <asm/sigcontext.h>

static struct hard_trap_info {
	unsigned char tt;	/* Trap type code for MIPS R3xxx and R4xxx */
	unsigned char signo;	/* Signal that we map this trap into */
} hard_trap_info[] = {
	{ 6, SIGBUS },		/* instruction bus error */
	{ 7, SIGBUS },		/* data bus error */
	{ 9, SIGTRAP },		/* break */
/*	{ 11, SIGILL }, */	/* CPU unusable */
	{ 12, SIGFPE },		/* overflow */
	{ 13, SIGTRAP },	/* trap */
	{ 14, SIGSEGV },	/* virtual instruction cache coherency */
	{ 15, SIGFPE },		/* floating point exception */
	{ 23, SIGSEGV },	/* watch */
	{ 31, SIGSEGV },	/* virtual data cache coherency */
	{ 0, 0}			/* Must be last */
};

struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
{
	{ "zero", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[0]) },
	{ "at", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[1]) },
	{ "v0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[2]) },
	{ "v1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[3]) },
	{ "a0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[4]) },
	{ "a1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[5]) },
	{ "a2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[6]) },
	{ "a3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[7]) },
	{ "t0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[8]) },
	{ "t1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[9]) },
	{ "t2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[10]) },
	{ "t3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[11]) },
	{ "t4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[12]) },
	{ "t5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[13]) },
	{ "t6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[14]) },
	{ "t7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[15]) },
	{ "s0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[16]) },
	{ "s1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[17]) },
	{ "s2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[18]) },
	{ "s3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[19]) },
	{ "s4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[20]) },
	{ "s5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[21]) },
	{ "s6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[22]) },
	{ "s7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[23]) },
	{ "t8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[24]) },
	{ "t9", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[25]) },
	{ "k0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[26]) },
	{ "k1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[27]) },
	{ "gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[28]) },
	{ "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[29]) },
	{ "s8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[30]) },
	{ "ra", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[31]) },
	{ "sr", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_status) },
	{ "lo", GDB_SIZEOF_REG, offsetof(struct pt_regs, lo) },
	{ "hi", GDB_SIZEOF_REG, offsetof(struct pt_regs, hi) },
	{ "bad", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_badvaddr) },
	{ "cause", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_cause) },
	{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_epc) },
	{ "f0", GDB_SIZEOF_REG, 0 },
	{ "f1", GDB_SIZEOF_REG, 1 },
	{ "f2", GDB_SIZEOF_REG, 2 },
	{ "f3", GDB_SIZEOF_REG, 3 },
	{ "f4", GDB_SIZEOF_REG, 4 },
	{ "f5", GDB_SIZEOF_REG, 5 },
	{ "f6", GDB_SIZEOF_REG, 6 },
	{ "f7", GDB_SIZEOF_REG, 7 },
	{ "f8", GDB_SIZEOF_REG, 8 },
	{ "f9", GDB_SIZEOF_REG, 9 },
	{ "f10", GDB_SIZEOF_REG, 10 },
	{ "f11", GDB_SIZEOF_REG, 11 },
	{ "f12", GDB_SIZEOF_REG, 12 },
	{ "f13", GDB_SIZEOF_REG, 13 },
	{ "f14", GDB_SIZEOF_REG, 14 },
	{ "f15", GDB_SIZEOF_REG, 15 },
	{ "f16", GDB_SIZEOF_REG, 16 },
	{ "f17", GDB_SIZEOF_REG, 17 },
	{ "f18", GDB_SIZEOF_REG, 18 },
	{ "f19", GDB_SIZEOF_REG, 19 },
	{ "f20", GDB_SIZEOF_REG, 20 },
	{ "f21", GDB_SIZEOF_REG, 21 },
	{ "f22", GDB_SIZEOF_REG, 22 },
	{ "f23", GDB_SIZEOF_REG, 23 },
	{ "f24", GDB_SIZEOF_REG, 24 },
	{ "f25", GDB_SIZEOF_REG, 25 },
	{ "f26", GDB_SIZEOF_REG, 26 },
	{ "f27", GDB_SIZEOF_REG, 27 },
	{ "f28", GDB_SIZEOF_REG, 28 },
	{ "f29", GDB_SIZEOF_REG, 29 },
	{ "f30", GDB_SIZEOF_REG, 30 },
	{ "f31", GDB_SIZEOF_REG, 31 },
	{ "fsr", GDB_SIZEOF_REG, 0 },
	{ "fir", GDB_SIZEOF_REG, 0 },
};

int dbg_set_reg(int regno, void *mem, struct pt_regs *regs)
{
	int fp_reg;

	if (regno < 0 || regno >= DBG_MAX_REG_NUM)
		return -EINVAL;

	if (dbg_reg_def[regno].offset != -1 && regno < 38) {
		memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
		       dbg_reg_def[regno].size);
	} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
		/* FP registers 38 -> 69 */
		if (!(regs->cp0_status & ST0_CU1))
			return 0;
		if (regno == 70) {
			/* Process the fcr31/fsr (register 70) */
			memcpy((void *)&current->thread.fpu.fcr31, mem,
			       dbg_reg_def[regno].size);
			goto out_save;
		} else if (regno == 71) {
			/* Ignore the fir (register 71) */
			goto out_save;
		}
		fp_reg = dbg_reg_def[regno].offset;
		memcpy((void *)&current->thread.fpu.fpr[fp_reg], mem,
		       dbg_reg_def[regno].size);
out_save:
		restore_fp(current);
	}

	return 0;
}

char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs)
{
	int fp_reg;

	if (regno >= DBG_MAX_REG_NUM || regno < 0)
		return NULL;

	if (dbg_reg_def[regno].offset != -1 && regno < 38) {
		/* First 38 registers */
		memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
		       dbg_reg_def[regno].size);
	} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
		/* FP registers 38 -> 69 */
		if (!(regs->cp0_status & ST0_CU1))
			goto out;
		save_fp(current);
		if (regno == 70) {
			/* Process the fcr31/fsr (register 70) */
			memcpy(mem, (void *)&current->thread.fpu.fcr31,
			       dbg_reg_def[regno].size);
			goto out;
		} else if (regno == 71) {
			/* Ignore the fir (register 71) */
			memset(mem, 0, dbg_reg_def[regno].size);
			goto out;
		}
		fp_reg = dbg_reg_def[regno].offset;
		memcpy(mem, (void *)&current->thread.fpu.fpr[fp_reg],
		       dbg_reg_def[regno].size);
	}

out:
	return dbg_reg_def[regno].name;

}

void arch_kgdb_breakpoint(void)
{
	__asm__ __volatile__(
		".globl breakinst\n\t"
		".set\tnoreorder\n\t"
		"nop\n"
		"breakinst:\tbreak\n\t"
		"nop\n\t"
		".set\treorder");
}

static void kgdb_call_nmi_hook(void *ignored)
{
	kgdb_nmicallback(raw_smp_processor_id(), NULL);
}

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

static int compute_signal(int tt)
{
	struct hard_trap_info *ht;

	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
		if (ht->tt == tt)
			return ht->signo;

	return SIGHUP;		/* default for things we don't know about */
}

/*
 * Similar to regs_to_gdb_regs() except that process is sleeping and so
 * we may not be able to get all the info.
 */
void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
{
	int reg;
	struct thread_info *ti = task_thread_info(p);
	unsigned long ksp = (unsigned long)ti + THREAD_SIZE - 32;
	struct pt_regs *regs = (struct pt_regs *)ksp - 1;
#if (KGDB_GDB_REG_SIZE == 32)
	u32 *ptr = (u32 *)gdb_regs;
#else
	u64 *ptr = (u64 *)gdb_regs;
#endif

	for (reg = 0; reg < 16; reg++)
		*(ptr++) = regs->regs[reg];

	/* S0 - S7 */
	for (reg = 16; reg < 24; reg++)
		*(ptr++) = regs->regs[reg];

	for (reg = 24; reg < 28; reg++)
		*(ptr++) = 0;

	/* GP, SP, FP, RA */
	for (reg = 28; reg < 32; reg++)
		*(ptr++) = regs->regs[reg];

	*(ptr++) = regs->cp0_status;
	*(ptr++) = regs->lo;
	*(ptr++) = regs->hi;
	*(ptr++) = regs->cp0_badvaddr;
	*(ptr++) = regs->cp0_cause;
	*(ptr++) = regs->cp0_epc;
}

void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
{
	regs->cp0_epc = pc;
}

/*
 * Calls linux_debug_hook before the kernel dies. If KGDB is enabled,
 * then try to fall into the debugger
 */
static int kgdb_mips_notify(struct notifier_block *self, unsigned long cmd,
			    void *ptr)
{
	struct die_args *args = (struct die_args *)ptr;
	struct pt_regs *regs = args->regs;
	int trap = (regs->cp0_cause & 0x7c) >> 2;

#ifdef CONFIG_KPROBES
	/*
	 * Return immediately if the kprobes fault notifier has set
	 * DIE_PAGE_FAULT.
	 */
	if (cmd == DIE_PAGE_FAULT)
		return NOTIFY_DONE;
#endif /* CONFIG_KPROBES */

	/* Userspace events, ignore. */
	if (user_mode(regs))
		return NOTIFY_DONE;

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

	if (kgdb_handle_exception(trap, compute_signal(trap), cmd, regs))
		return NOTIFY_DONE;

	if (atomic_read(&kgdb_setting_breakpoint))
		if ((trap == 9) && (regs->cp0_epc == (unsigned long)breakinst))
			regs->cp0_epc += 4;

	/* In SMP mode, __flush_cache_all does IPI */
	local_irq_enable();
	__flush_cache_all();

	return NOTIFY_STOP;
}

#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
int kgdb_ll_trap(int cmd, const char *str,
		 struct pt_regs *regs, long err, int trap, int sig)
{
	struct die_args args = {
		.regs	= regs,
		.str	= str,
		.err	= err,
		.trapnr = trap,
		.signr	= sig,

	};

	if (!kgdb_io_module_registered)
		return NOTIFY_DONE;

	return kgdb_mips_notify(NULL, cmd, &args);
}
#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */

static struct notifier_block kgdb_notifier = {
	.notifier_call = kgdb_mips_notify,
};

/*
 * Handle the 'c' command
 */
int kgdb_arch_handle_exception(int vector, int signo, int err_code,
			       char *remcom_in_buffer, char *remcom_out_buffer,
			       struct pt_regs *regs)
{
	char *ptr;
	unsigned long address;

	switch (remcom_in_buffer[0]) {
	case 'c':
		/* handle the optional parameter */
		ptr = &remcom_in_buffer[1];
		if (kgdb_hex2long(&ptr, &address))
			regs->cp0_epc = address;

		return 0;
	}

	return -1;
}

struct kgdb_arch arch_kgdb_ops;

/*
 * We use kgdb_early_setup so that functions we need to call now don't
 * cause trouble when called again later.
 */
int kgdb_arch_init(void)
{
	union mips_instruction insn = {
		.r_format = {
			.opcode = spec_op,
			.func	= break_op,
		}
	};
	memcpy(arch_kgdb_ops.gdb_bpt_instr, insn.byte, BREAK_INSTR_SIZE);

	register_die_notifier(&kgdb_notifier);

	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_die_notifier(&kgdb_notifier);
}
Commit	Line	Data
88547001 JW	1	/*
	2	* Originally written by Glenn Engel, Lake Stevens Instrument Division
	3	*
	4	* Contributed by HP Systems
	5	*
	6	* Modified for Linux/MIPS (and MIPS in general) by Andreas Busse
	7	* Send complaints, suggestions etc. to <[email protected]>
	8	*
	9	* Copyright (C) 1995 Andreas Busse
	10	*
	11	* Copyright (C) 2003 MontaVista Software Inc.
	12	* Author: Jun Sun, [email protected] or [email protected]
	13	*
	14	* Copyright (C) 2004-2005 MontaVista Software Inc.
	15	* Author: Manish Lachwani, [email protected] or [email protected]
	16	*
	17	* Copyright (C) 2007-2008 Wind River Systems, Inc.
	18	* Author/Maintainer: Jason Wessel, [email protected]
	19	*
	20	* This file is licensed under the terms of the GNU General Public License
	21	* version 2. This program is licensed "as is" without any warranty of any
	22	* kind, whether express or implied.
	23	*/
	24
	25	#include <linux/ptrace.h> /* for linux pt_regs struct */
	26	#include <linux/kgdb.h>
	27	#include <linux/kdebug.h>
	28	#include <linux/sched.h>
631330f5	29	#include <linux/smp.h>
88547001 JW	30	#include <asm/inst.h>
	31	#include <asm/fpu.h>
	32	#include <asm/cacheflush.h>
	33	#include <asm/processor.h>
	34	#include <asm/sigcontext.h>
	35
	36	static struct hard_trap_info {
	37	unsigned char tt; /* Trap type code for MIPS R3xxx and R4xxx */
	38	unsigned char signo; /* Signal that we map this trap into */
	39	} hard_trap_info[] = {
	40	{ 6, SIGBUS }, /* instruction bus error */
	41	{ 7, SIGBUS }, /* data bus error */
	42	{ 9, SIGTRAP }, /* break */
70342287	43	/* { 11, SIGILL }, / / CPU unusable */
88547001 JW	44	{ 12, SIGFPE }, /* overflow */
	45	{ 13, SIGTRAP }, /* trap */
	46	{ 14, SIGSEGV }, /* virtual instruction cache coherency */
	47	{ 15, SIGFPE }, /* floating point exception */
	48	{ 23, SIGSEGV }, /* watch */
	49	{ 31, SIGSEGV }, /* virtual data cache coherency */
	50	{ 0, 0} /* Must be last */
	51	};
	52
0896a9be JW	53	struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
	54	{
	55	{ "zero", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[0]) },
	56	{ "at", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[1]) },
	57	{ "v0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[2]) },
	58	{ "v1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[3]) },
	59	{ "a0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[4]) },
	60	{ "a1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[5]) },
	61	{ "a2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[6]) },
	62	{ "a3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[7]) },
	63	{ "t0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[8]) },
	64	{ "t1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[9]) },
	65	{ "t2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[10]) },
	66	{ "t3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[11]) },
	67	{ "t4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[12]) },
	68	{ "t5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[13]) },
	69	{ "t6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[14]) },
	70	{ "t7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[15]) },
	71	{ "s0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[16]) },
	72	{ "s1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[17]) },
	73	{ "s2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[18]) },
	74	{ "s3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[19]) },
	75	{ "s4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[20]) },
	76	{ "s5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[21]) },
	77	{ "s6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[22]) },
	78	{ "s7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[23]) },
	79	{ "t8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[24]) },
	80	{ "t9", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[25]) },
	81	{ "k0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[26]) },
	82	{ "k1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[27]) },
	83	{ "gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[28]) },
	84	{ "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[29]) },
	85	{ "s8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[30]) },
	86	{ "ra", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[31]) },
	87	{ "sr", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_status) },
	88	{ "lo", GDB_SIZEOF_REG, offsetof(struct pt_regs, lo) },
	89	{ "hi", GDB_SIZEOF_REG, offsetof(struct pt_regs, hi) },
	90	{ "bad", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_badvaddr) },
	91	{ "cause", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_cause) },
	92	{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_epc) },
	93	{ "f0", GDB_SIZEOF_REG, 0 },
	94	{ "f1", GDB_SIZEOF_REG, 1 },
	95	{ "f2", GDB_SIZEOF_REG, 2 },
	96	{ "f3", GDB_SIZEOF_REG, 3 },
	97	{ "f4", GDB_SIZEOF_REG, 4 },
	98	{ "f5", GDB_SIZEOF_REG, 5 },
	99	{ "f6", GDB_SIZEOF_REG, 6 },
	100	{ "f7", GDB_SIZEOF_REG, 7 },
	101	{ "f8", GDB_SIZEOF_REG, 8 },
	102	{ "f9", GDB_SIZEOF_REG, 9 },
	103	{ "f10", GDB_SIZEOF_REG, 10 },
	104	{ "f11", GDB_SIZEOF_REG, 11 },
	105	{ "f12", GDB_SIZEOF_REG, 12 },
	106	{ "f13", GDB_SIZEOF_REG, 13 },
	107	{ "f14", GDB_SIZEOF_REG, 14 },
	108	{ "f15", GDB_SIZEOF_REG, 15 },
	109	{ "f16", GDB_SIZEOF_REG, 16 },
	110	{ "f17", GDB_SIZEOF_REG, 17 },
	111	{ "f18", GDB_SIZEOF_REG, 18 },
	112	{ "f19", GDB_SIZEOF_REG, 19 },
	113	{ "f20", GDB_SIZEOF_REG, 20 },
	114	{ "f21", GDB_SIZEOF_REG, 21 },
	115	{ "f22", GDB_SIZEOF_REG, 22 },
	116	{ "f23", GDB_SIZEOF_REG, 23 },
117	{ "f24", GDB_SIZEOF_REG, 24 },
118	{ "f25", GDB_SIZEOF_REG, 25 },
119	{ "f26", GDB_SIZEOF_REG, 26 },
120	{ "f27", GDB_SIZEOF_REG, 27 },
121	{ "f28", GDB_SIZEOF_REG, 28 },
122	{ "f29", GDB_SIZEOF_REG, 29 },
123	{ "f30", GDB_SIZEOF_REG, 30 },
124	{ "f31", GDB_SIZEOF_REG, 31 },
125	{ "fsr", GDB_SIZEOF_REG, 0 },
126	{ "fir", GDB_SIZEOF_REG, 0 },
127	};
128
129	int dbg_set_reg(int regno, void mem, struct pt_regs regs)
130	{
131	int fp_reg;
132
133	if (regno < 0 \|\| regno >= DBG_MAX_REG_NUM)
134	return -EINVAL;
135
136	if (dbg_reg_def[regno].offset != -1 && regno < 38) {
137	memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
138	dbg_reg_def[regno].size);
139	} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
140	/* FP registers 38 -> 69 */
141	if (!(regs->cp0_status & ST0_CU1))
142	return 0;
143	if (regno == 70) {
144	/* Process the fcr31/fsr (register 70) */
145	memcpy((void *)&current->thread.fpu.fcr31, mem,
146	dbg_reg_def[regno].size);
147	goto out_save;
148	} else if (regno == 71) {
149	/* Ignore the fir (register 71) */
150	goto out_save;
151	}
152	fp_reg = dbg_reg_def[regno].offset;
153	memcpy((void *)&current->thread.fpu.fpr[fp_reg], mem,
154	dbg_reg_def[regno].size);
155	out_save:
156	restore_fp(current);
157	}
158
159	return 0;
160	}
161
162	char dbg_get_reg(int regno, void mem, struct pt_regs *regs)
163	{
164	int fp_reg;
165
166	if (regno >= DBG_MAX_REG_NUM \|\| regno < 0)
167	return NULL;
168
169	if (dbg_reg_def[regno].offset != -1 && regno < 38) {
170	/* First 38 registers */
171	memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
172	dbg_reg_def[regno].size);
173	} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
174	/* FP registers 38 -> 69 */
175	if (!(regs->cp0_status & ST0_CU1))
176	goto out;
177	save_fp(current);
178	if (regno == 70) {
179	/* Process the fcr31/fsr (register 70) */
180	memcpy(mem, (void *)&current->thread.fpu.fcr31,
181	dbg_reg_def[regno].size);
182	goto out;
183	} else if (regno == 71) {
184	/* Ignore the fir (register 71) */
185	memset(mem, 0, dbg_reg_def[regno].size);
186	goto out;
187	}
188	fp_reg = dbg_reg_def[regno].offset;
189	memcpy(mem, (void *)&current->thread.fpu.fpr[fp_reg],
190	dbg_reg_def[regno].size);
191	}
192
193	out:
194	return dbg_reg_def[regno].name;
195
196	}
197
88547001 JW	198	void arch_kgdb_breakpoint(void)
	199	{
	200	__asm__ __volatile__(
	201	".globl breakinst\n\t"
	202	".set\tnoreorder\n\t"
	203	"nop\n"
	204	"breakinst:\tbreak\n\t"
	205	"nop\n\t"
	206	".set\treorder");
	207	}
	208
	209	static void kgdb_call_nmi_hook(void *ignored)
	210	{
9391d6bb	211	kgdb_nmicallback(raw_smp_processor_id(), NULL);
88547001 JW	212	}
	213
	214	void kgdb_roundup_cpus(unsigned long flags)
	215	{
	216	local_irq_enable();
e522b7cc	217	smp_call_function(kgdb_call_nmi_hook, NULL, 0);
88547001 JW	218	local_irq_disable();
	219	}
	220
	221	static int compute_signal(int tt)
	222	{
	223	struct hard_trap_info *ht;
	224
	225	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
	226	if (ht->tt == tt)
	227	return ht->signo;
	228
	229	return SIGHUP; /* default for things we don't know about */
	230	}
	231
88547001 JW	232	/*
	233	* Similar to regs_to_gdb_regs() except that process is sleeping and so
	234	* we may not be able to get all the info.
	235	*/
	236	void sleeping_thread_to_gdb_regs(unsigned long gdb_regs, struct task_struct p)
	237	{
	238	int reg;
	239	struct thread_info *ti = task_thread_info(p);
	240	unsigned long ksp = (unsigned long)ti + THREAD_SIZE - 32;
	241	struct pt_regs regs = (struct pt_regs )ksp - 1;
	242	#if (KGDB_GDB_REG_SIZE == 32)
	243	u32 ptr = (u32 )gdb_regs;
	244	#else
	245	u64 ptr = (u64 )gdb_regs;
	246	#endif
	247
	248	for (reg = 0; reg < 16; reg++)
	249	*(ptr++) = regs->regs[reg];
	250
	251	/* S0 - S7 */
	252	for (reg = 16; reg < 24; reg++)
	253	*(ptr++) = regs->regs[reg];
	254
	255	for (reg = 24; reg < 28; reg++)
	256	*(ptr++) = 0;
	257
	258	/* GP, SP, FP, RA */
	259	for (reg = 28; reg < 32; reg++)
	260	*(ptr++) = regs->regs[reg];
	261
	262	*(ptr++) = regs->cp0_status;
	263	*(ptr++) = regs->lo;
	264	*(ptr++) = regs->hi;
	265	*(ptr++) = regs->cp0_badvaddr;
	266	*(ptr++) = regs->cp0_cause;
	267	*(ptr++) = regs->cp0_epc;
	268	}
	269
dcc78711 JW	270	void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
	271	{
	272	regs->cp0_epc = pc;
	273	}
	274
88547001 JW	275	/*
	276	* Calls linux_debug_hook before the kernel dies. If KGDB is enabled,
	277	* then try to fall into the debugger
	278	*/
	279	static int kgdb_mips_notify(struct notifier_block *self, unsigned long cmd,
	280	void *ptr)
	281	{
	282	struct die_args args = (struct die_args )ptr;
	283	struct pt_regs *regs = args->regs;
	284	int trap = (regs->cp0_cause & 0x7c) >> 2;
	285
f0a996ee JW	286	#ifdef CONFIG_KPROBES
	287	/*
	288	* Return immediately if the kprobes fault notifier has set
	289	* DIE_PAGE_FAULT.
	290	*/
	291	if (cmd == DIE_PAGE_FAULT)
	292	return NOTIFY_DONE;
	293	#endif /* CONFIG_KPROBES */
	294
eefc3f32	295	/* Userspace events, ignore. */
88547001 JW	296	if (user_mode(regs))
	297	return NOTIFY_DONE;
	298
	299	if (atomic_read(&kgdb_active) != -1)
	300	kgdb_nmicallback(smp_processor_id(), regs);
	301
5dd11d5d	302	if (kgdb_handle_exception(trap, compute_signal(trap), cmd, regs))
88547001 JW	303	return NOTIFY_DONE;
	304
	305	if (atomic_read(&kgdb_setting_breakpoint))
	306	if ((trap == 9) && (regs->cp0_epc == (unsigned long)breakinst))
	307	regs->cp0_epc += 4;
	308
	309	/* In SMP mode, __flush_cache_all does IPI */
	310	local_irq_enable();
	311	__flush_cache_all();
	312
	313	return NOTIFY_STOP;
	314	}
	315
5dd11d5d JW	316	#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
	317	int kgdb_ll_trap(int cmd, const char *str,
	318	struct pt_regs *regs, long err, int trap, int sig)
	319	{
	320	struct die_args args = {
	321	.regs = regs,
	322	.str = str,
	323	.err = err,
70342287	324	.trapnr = trap,
5dd11d5d JW	325	.signr = sig,
	326
	327	};
	328
	329	if (!kgdb_io_module_registered)
	330	return NOTIFY_DONE;
	331
	332	return kgdb_mips_notify(NULL, cmd, &args);
	333	}
	334	#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
	335
88547001 JW	336	static struct notifier_block kgdb_notifier = {
	337	.notifier_call = kgdb_mips_notify,
	338	};
	339
	340	/*
7aeb48b7	341	* Handle the 'c' command
88547001 JW	342	*/
	343	int kgdb_arch_handle_exception(int vector, int signo, int err_code,
	344	char remcom_in_buffer, char remcom_out_buffer,
	345	struct pt_regs *regs)
	346	{
	347	char *ptr;
	348	unsigned long address;
88547001 JW	349
88547001 JW	350	switch (remcom_in_buffer[0]) {
88547001 JW	351	case 'c':
	352	/* handle the optional parameter */
	353	ptr = &remcom_in_buffer[1];
	354	if (kgdb_hex2long(&ptr, &address))
	355	regs->cp0_epc = address;
	356
88547001 JW	357	return 0;
	358	}
	359
	360	return -1;
	361	}
	362
	363	struct kgdb_arch arch_kgdb_ops;
	364
	365	/*
	366	* We use kgdb_early_setup so that functions we need to call now don't
	367	* cause trouble when called again later.
	368	*/
	369	int kgdb_arch_init(void)
	370	{
	371	union mips_instruction insn = {
	372	.r_format = {
	373	.opcode = spec_op,
70342287	374	.func = break_op,
88547001 JW	375	}
	376	};
	377	memcpy(arch_kgdb_ops.gdb_bpt_instr, insn.byte, BREAK_INSTR_SIZE);
	378
	379	register_die_notifier(&kgdb_notifier);
	380
	381	return 0;
	382	}
	383
	384	/*
	385	* kgdb_arch_exit - Perform any architecture specific uninitalization.
	386	*
	387	* This function will handle the uninitalization of any architecture
	388	* specific callbacks, for dynamic registration and unregistration.
	389	*/
	390	void kgdb_arch_exit(void)
	391	{
	392	unregister_die_notifier(&kgdb_notifier);
	393	}