[linux-2.6-block.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 <andy@waldorf-gmbh.de>
 *
 *  Copyright (C) 1995 Andreas Busse
 *
 *  Copyright (C) 2003 MontaVista Software Inc.
 *  Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
 *
 *  Copyright (C) 2004-2005 MontaVista Software Inc.
 *  Author: Manish Lachwani, mlachwani@mvista.com or manish@koffee-break.com
 *
 *  Copyright (C) 2007-2008 Wind River Systems, Inc.
 *  Author/Maintainer: Jason Wessel, jason.wessel@windriver.com
 *
 *  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>
#include <linux/uaccess.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)
{
	mm_segment_t old_fs;

	old_fs = get_fs();
	set_fs(get_ds());

	kgdb_nmicallback(raw_smp_processor_id(), NULL);

	set_fs(old_fs);
}

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;
#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++) = 0;

	/* S0 - S7 */
	*(ptr++) = p->thread.reg16;
	*(ptr++) = p->thread.reg17;
	*(ptr++) = p->thread.reg18;
	*(ptr++) = p->thread.reg19;
	*(ptr++) = p->thread.reg20;
	*(ptr++) = p->thread.reg21;
	*(ptr++) = p->thread.reg22;
	*(ptr++) = p->thread.reg23;

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

	/* GP, SP, FP, RA */
	*(ptr++) = (long)p;
	*(ptr++) = p->thread.reg29;
	*(ptr++) = p->thread.reg30;
	*(ptr++) = p->thread.reg31;

	*(ptr++) = p->thread.cp0_status;

	/* lo, hi */
	*(ptr++) = 0;
	*(ptr++) = 0;

	/*
	 * BadVAddr, Cause
	 * Ideally these would come from the last exception frame up the stack
	 * but that requires unwinding, otherwise we can't know much for sure.
	 */
	*(ptr++) = 0;
	*(ptr++) = 0;

	/*
	 * PC
	 * use return address (RA), i.e. the moment after return from resume()
	 */
	*(ptr++) = p->thread.reg31;
}

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;
	mm_segment_t old_fs;

#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;

	/* Kernel mode. Set correct address limit */
	old_fs = get_fs();
	set_fs(get_ds());

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

	if (kgdb_handle_exception(trap, compute_signal(trap), cmd, regs)) {
		set_fs(old_fs);
		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();

	set_fs(old_fs);
	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;

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 <andy@waldorf-gmbh.de>
	8	*
	9	* Copyright (C) 1995 Andreas Busse
	10	*
	11	* Copyright (C) 2003 MontaVista Software Inc.
	12	* Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
	13	*
	14	* Copyright (C) 2004-2005 MontaVista Software Inc.
	15	* Author: Manish Lachwani, mlachwani@mvista.com or manish@koffee-break.com
	16	*
	17	* Copyright (C) 2007-2008 Wind River Systems, Inc.
	18	* Author/Maintainer: Jason Wessel, jason.wessel@windriver.com
	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>
7c0f6ba6	35	#include <linux/uaccess.h>
88547001 JW	36
	37	static struct hard_trap_info {
	38	unsigned char tt; /* Trap type code for MIPS R3xxx and R4xxx */
	39	unsigned char signo; /* Signal that we map this trap into */
	40	} hard_trap_info[] = {
	41	{ 6, SIGBUS }, /* instruction bus error */
	42	{ 7, SIGBUS }, /* data bus error */
	43	{ 9, SIGTRAP }, /* break */
70342287	44	/* { 11, SIGILL }, / / CPU unusable */
88547001 JW	45	{ 12, SIGFPE }, /* overflow */
	46	{ 13, SIGTRAP }, /* trap */
	47	{ 14, SIGSEGV }, /* virtual instruction cache coherency */
	48	{ 15, SIGFPE }, /* floating point exception */
	49	{ 23, SIGSEGV }, /* watch */
	50	{ 31, SIGSEGV }, /* virtual data cache coherency */
	51	{ 0, 0} /* Must be last */
	52	};
	53
0896a9be JW	54	struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
	55	{
	56	{ "zero", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[0]) },
	57	{ "at", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[1]) },
	58	{ "v0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[2]) },
	59	{ "v1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[3]) },
	60	{ "a0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[4]) },
	61	{ "a1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[5]) },
	62	{ "a2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[6]) },
	63	{ "a3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[7]) },
	64	{ "t0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[8]) },
	65	{ "t1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[9]) },
	66	{ "t2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[10]) },
	67	{ "t3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[11]) },
	68	{ "t4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[12]) },
	69	{ "t5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[13]) },
	70	{ "t6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[14]) },
	71	{ "t7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[15]) },
	72	{ "s0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[16]) },
	73	{ "s1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[17]) },
	74	{ "s2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[18]) },
	75	{ "s3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[19]) },
	76	{ "s4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[20]) },
	77	{ "s5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[21]) },
	78	{ "s6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[22]) },
	79	{ "s7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[23]) },
	80	{ "t8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[24]) },
	81	{ "t9", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[25]) },
	82	{ "k0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[26]) },
	83	{ "k1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[27]) },
	84	{ "gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[28]) },
	85	{ "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[29]) },
	86	{ "s8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[30]) },
	87	{ "ra", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[31]) },
	88	{ "sr", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_status) },
	89	{ "lo", GDB_SIZEOF_REG, offsetof(struct pt_regs, lo) },
	90	{ "hi", GDB_SIZEOF_REG, offsetof(struct pt_regs, hi) },
	91	{ "bad", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_badvaddr) },
	92	{ "cause", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_cause) },
	93	{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_epc) },
	94	{ "f0", GDB_SIZEOF_REG, 0 },
	95	{ "f1", GDB_SIZEOF_REG, 1 },
	96	{ "f2", GDB_SIZEOF_REG, 2 },
	97	{ "f3", GDB_SIZEOF_REG, 3 },
	98	{ "f4", GDB_SIZEOF_REG, 4 },
	99	{ "f5", GDB_SIZEOF_REG, 5 },
	100	{ "f6", GDB_SIZEOF_REG, 6 },
	101	{ "f7", GDB_SIZEOF_REG, 7 },
	102	{ "f8", GDB_SIZEOF_REG, 8 },
	103	{ "f9", GDB_SIZEOF_REG, 9 },
	104	{ "f10", GDB_SIZEOF_REG, 10 },
	105	{ "f11", GDB_SIZEOF_REG, 11 },
	106	{ "f12", GDB_SIZEOF_REG, 12 },
	107	{ "f13", GDB_SIZEOF_REG, 13 },
	108	{ "f14", GDB_SIZEOF_REG, 14 },
	109	{ "f15", GDB_SIZEOF_REG, 15 },
	110	{ "f16", GDB_SIZEOF_REG, 16 },
	111	{ "f17", GDB_SIZEOF_REG, 17 },
	112	{ "f18", GDB_SIZEOF_REG, 18 },
	113	{ "f19", GDB_SIZEOF_REG, 19 },
	114	{ "f20", GDB_SIZEOF_REG, 20 },
	115	{ "f21", GDB_SIZEOF_REG, 21 },
	116	{ "f22", GDB_SIZEOF_REG, 22 },
	117	{ "f23", GDB_SIZEOF_REG, 23 },
118	{ "f24", GDB_SIZEOF_REG, 24 },
119	{ "f25", GDB_SIZEOF_REG, 25 },
120	{ "f26", GDB_SIZEOF_REG, 26 },
121	{ "f27", GDB_SIZEOF_REG, 27 },
122	{ "f28", GDB_SIZEOF_REG, 28 },
123	{ "f29", GDB_SIZEOF_REG, 29 },
124	{ "f30", GDB_SIZEOF_REG, 30 },
125	{ "f31", GDB_SIZEOF_REG, 31 },
126	{ "fsr", GDB_SIZEOF_REG, 0 },
127	{ "fir", GDB_SIZEOF_REG, 0 },
128	};
129
130	int dbg_set_reg(int regno, void mem, struct pt_regs regs)
131	{
132	int fp_reg;
133
134	if (regno < 0 \|\| regno >= DBG_MAX_REG_NUM)
135	return -EINVAL;
136
137	if (dbg_reg_def[regno].offset != -1 && regno < 38) {
138	memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
139	dbg_reg_def[regno].size);
140	} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
141	/* FP registers 38 -> 69 */
142	if (!(regs->cp0_status & ST0_CU1))
143	return 0;
144	if (regno == 70) {
145	/* Process the fcr31/fsr (register 70) */
146	memcpy((void *)&current->thread.fpu.fcr31, mem,
147	dbg_reg_def[regno].size);
148	goto out_save;
149	} else if (regno == 71) {
150	/* Ignore the fir (register 71) */
151	goto out_save;
152	}
153	fp_reg = dbg_reg_def[regno].offset;
154	memcpy((void *)&current->thread.fpu.fpr[fp_reg], mem,
155	dbg_reg_def[regno].size);
156	out_save:
157	restore_fp(current);
158	}
159
160	return 0;
161	}
162
163	char dbg_get_reg(int regno, void mem, struct pt_regs *regs)
164	{
165	int fp_reg;
166
167	if (regno >= DBG_MAX_REG_NUM \|\| regno < 0)
168	return NULL;
169
170	if (dbg_reg_def[regno].offset != -1 && regno < 38) {
171	/* First 38 registers */
172	memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
173	dbg_reg_def[regno].size);
174	} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
175	/* FP registers 38 -> 69 */
176	if (!(regs->cp0_status & ST0_CU1))
177	goto out;
178	save_fp(current);
179	if (regno == 70) {
180	/* Process the fcr31/fsr (register 70) */
181	memcpy(mem, (void *)&current->thread.fpu.fcr31,
182	dbg_reg_def[regno].size);
183	goto out;
184	} else if (regno == 71) {
185	/* Ignore the fir (register 71) */
186	memset(mem, 0, dbg_reg_def[regno].size);
187	goto out;
188	}
189	fp_reg = dbg_reg_def[regno].offset;
190	memcpy(mem, (void *)&current->thread.fpu.fpr[fp_reg],
191	dbg_reg_def[regno].size);
192	}
193
194	out:
195	return dbg_reg_def[regno].name;
196
197	}
198
88547001 JW	199	void arch_kgdb_breakpoint(void)
	200	{
	201	__asm__ __volatile__(
	202	".globl breakinst\n\t"
	203	".set\tnoreorder\n\t"
	204	"nop\n"
	205	"breakinst:\tbreak\n\t"
	206	"nop\n\t"
	207	".set\treorder");
	208	}
	209
	210	static void kgdb_call_nmi_hook(void *ignored)
	211	{
6ebda44f LY	212	mm_segment_t old_fs;
	213
	214	old_fs = get_fs();
	215	set_fs(get_ds());
	216
9391d6bb	217	kgdb_nmicallback(raw_smp_processor_id(), NULL);
6ebda44f LY	218
6ebda44f LY	219	set_fs(old_fs);
88547001 JW	220	}
	221
	222	void kgdb_roundup_cpus(unsigned long flags)
	223	{
	224	local_irq_enable();
e522b7cc	225	smp_call_function(kgdb_call_nmi_hook, NULL, 0);
88547001 JW	226	local_irq_disable();
	227	}
	228
	229	static int compute_signal(int tt)
	230	{
	231	struct hard_trap_info *ht;
	232
	233	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
	234	if (ht->tt == tt)
	235	return ht->signo;
	236
	237	return SIGHUP; /* default for things we don't know about */
	238	}
	239
88547001 JW	240	/*
	241	* Similar to regs_to_gdb_regs() except that process is sleeping and so
	242	* we may not be able to get all the info.
	243	*/
	244	void sleeping_thread_to_gdb_regs(unsigned long gdb_regs, struct task_struct p)
	245	{
	246	int reg;
88547001 JW	247	#if (KGDB_GDB_REG_SIZE == 32)
	248	u32 ptr = (u32 )gdb_regs;
	249	#else
	250	u64 ptr = (u64 )gdb_regs;
	251	#endif
	252
	253	for (reg = 0; reg < 16; reg++)
162b270c	254	*(ptr++) = 0;
88547001 JW	255
88547001 JW	256	/* S0 - S7 */
162b270c JH	257	*(ptr++) = p->thread.reg16;
	258	*(ptr++) = p->thread.reg17;
	259	*(ptr++) = p->thread.reg18;
	260	*(ptr++) = p->thread.reg19;
	261	*(ptr++) = p->thread.reg20;
	262	*(ptr++) = p->thread.reg21;
	263	*(ptr++) = p->thread.reg22;
	264	*(ptr++) = p->thread.reg23;
88547001 JW	265
	266	for (reg = 24; reg < 28; reg++)
	267	*(ptr++) = 0;
	268
	269	/* GP, SP, FP, RA */
162b270c JH	270	*(ptr++) = (long)p;
	271	*(ptr++) = p->thread.reg29;
	272	*(ptr++) = p->thread.reg30;
	273	*(ptr++) = p->thread.reg31;
	274
	275	*(ptr++) = p->thread.cp0_status;
	276
	277	/* lo, hi */
	278	*(ptr++) = 0;
	279	*(ptr++) = 0;
	280
	281	/*
	282	* BadVAddr, Cause
	283	* Ideally these would come from the last exception frame up the stack
	284	* but that requires unwinding, otherwise we can't know much for sure.
	285	*/
	286	*(ptr++) = 0;
	287	*(ptr++) = 0;
	288
	289	/*
	290	* PC
	291	* use return address (RA), i.e. the moment after return from resume()
	292	*/
	293	*(ptr++) = p->thread.reg31;
88547001 JW	294	}
88547001 JW	295
dcc78711 JW	296	void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
	297	{
	298	regs->cp0_epc = pc;
	299	}
	300
88547001 JW	301	/*
	302	* Calls linux_debug_hook before the kernel dies. If KGDB is enabled,
	303	* then try to fall into the debugger
	304	*/
	305	static int kgdb_mips_notify(struct notifier_block *self, unsigned long cmd,
	306	void *ptr)
	307	{
	308	struct die_args args = (struct die_args )ptr;
	309	struct pt_regs *regs = args->regs;
	310	int trap = (regs->cp0_cause & 0x7c) >> 2;
6ebda44f	311	mm_segment_t old_fs;
88547001	312
f0a996ee JW	313	#ifdef CONFIG_KPROBES
	314	/*
	315	* Return immediately if the kprobes fault notifier has set
	316	* DIE_PAGE_FAULT.
	317	*/
	318	if (cmd == DIE_PAGE_FAULT)
	319	return NOTIFY_DONE;
	320	#endif /* CONFIG_KPROBES */
	321
eefc3f32	322	/* Userspace events, ignore. */
88547001 JW	323	if (user_mode(regs))
	324	return NOTIFY_DONE;
	325
6ebda44f LY	326	/* Kernel mode. Set correct address limit */
	327	old_fs = get_fs();
	328	set_fs(get_ds());
	329
88547001 JW	330	if (atomic_read(&kgdb_active) != -1)
	331	kgdb_nmicallback(smp_processor_id(), regs);
	332
6ebda44f LY	333	if (kgdb_handle_exception(trap, compute_signal(trap), cmd, regs)) {
6ebda44f LY	334	set_fs(old_fs);
88547001	335	return NOTIFY_DONE;
6ebda44f	336	}
88547001 JW	337
	338	if (atomic_read(&kgdb_setting_breakpoint))
	339	if ((trap == 9) && (regs->cp0_epc == (unsigned long)breakinst))
	340	regs->cp0_epc += 4;
	341
	342	/* In SMP mode, __flush_cache_all does IPI */
	343	local_irq_enable();
	344	__flush_cache_all();
	345
6ebda44f	346	set_fs(old_fs);
88547001 JW	347	return NOTIFY_STOP;
	348	}
	349
5dd11d5d JW	350	#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
	351	int kgdb_ll_trap(int cmd, const char *str,
	352	struct pt_regs *regs, long err, int trap, int sig)
	353	{
	354	struct die_args args = {
	355	.regs = regs,
	356	.str = str,
	357	.err = err,
70342287	358	.trapnr = trap,
5dd11d5d JW	359	.signr = sig,
	360
	361	};
	362
	363	if (!kgdb_io_module_registered)
	364	return NOTIFY_DONE;
	365
	366	return kgdb_mips_notify(NULL, cmd, &args);
	367	}
	368	#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
	369
88547001 JW	370	static struct notifier_block kgdb_notifier = {
	371	.notifier_call = kgdb_mips_notify,
	372	};
	373
	374	/*
7aeb48b7	375	* Handle the 'c' command
88547001 JW	376	*/
	377	int kgdb_arch_handle_exception(int vector, int signo, int err_code,
	378	char remcom_in_buffer, char remcom_out_buffer,
	379	struct pt_regs *regs)
	380	{
	381	char *ptr;
	382	unsigned long address;
88547001 JW	383
88547001 JW	384	switch (remcom_in_buffer[0]) {
88547001 JW	385	case 'c':
	386	/* handle the optional parameter */
	387	ptr = &remcom_in_buffer[1];
	388	if (kgdb_hex2long(&ptr, &address))
	389	regs->cp0_epc = address;
	390
88547001 JW	391	return 0;
	392	}
	393
	394	return -1;
	395	}
	396
	397	struct kgdb_arch arch_kgdb_ops;
	398
88547001 JW	399	int kgdb_arch_init(void)
	400	{
	401	union mips_instruction insn = {
	402	.r_format = {
	403	.opcode = spec_op,
70342287	404	.func = break_op,
88547001 JW	405	}
	406	};
	407	memcpy(arch_kgdb_ops.gdb_bpt_instr, insn.byte, BREAK_INSTR_SIZE);
	408
	409	register_die_notifier(&kgdb_notifier);
	410
	411	return 0;
	412	}
	413
	414	/*
	415	* kgdb_arch_exit - Perform any architecture specific uninitalization.
	416	*
	417	* This function will handle the uninitalization of any architecture
	418	* specific callbacks, for dynamic registration and unregistration.
	419	*/
	420	void kgdb_arch_exit(void)
	421	{
	422	unregister_die_notifier(&kgdb_notifier);
	423	}