[mirror_ubuntu-focal-kernel.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>
#include <asm/irq_regs.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");
}

void kgdb_call_nmi_hook(void *ignored)
{
	mm_segment_t old_fs;

	old_fs = get_fs();
	set_fs(KERNEL_DS);

	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());

	set_fs(old_fs);
}

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(KERNEL_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;
}

const struct kgdb_arch arch_kgdb_ops = {
#ifdef CONFIG_CPU_BIG_ENDIAN
	.gdb_bpt_instr = { spec_op << 2, 0x00, 0x00, break_op },
#else
	.gdb_bpt_instr = { break_op, 0x00, 0x00, spec_op << 2 },
#endif
};

int kgdb_arch_init(void)
{
	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>
ab8a6d82	36	#include <asm/irq_regs.h>
88547001 JW	37
	38	static struct hard_trap_info {
	39	unsigned char tt; /* Trap type code for MIPS R3xxx and R4xxx */
	40	unsigned char signo; /* Signal that we map this trap into */
	41	} hard_trap_info[] = {
	42	{ 6, SIGBUS }, /* instruction bus error */
	43	{ 7, SIGBUS }, /* data bus error */
	44	{ 9, SIGTRAP }, /* break */
70342287	45	/* { 11, SIGILL }, / / CPU unusable */
88547001 JW	46	{ 12, SIGFPE }, /* overflow */
	47	{ 13, SIGTRAP }, /* trap */
	48	{ 14, SIGSEGV }, /* virtual instruction cache coherency */
	49	{ 15, SIGFPE }, /* floating point exception */
	50	{ 23, SIGSEGV }, /* watch */
	51	{ 31, SIGSEGV }, /* virtual data cache coherency */
	52	{ 0, 0} /* Must be last */
	53	};
	54
0896a9be JW	55	struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] =
	56	{
	57	{ "zero", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[0]) },
	58	{ "at", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[1]) },
	59	{ "v0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[2]) },
	60	{ "v1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[3]) },
	61	{ "a0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[4]) },
	62	{ "a1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[5]) },
	63	{ "a2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[6]) },
	64	{ "a3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[7]) },
	65	{ "t0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[8]) },
	66	{ "t1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[9]) },
	67	{ "t2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[10]) },
	68	{ "t3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[11]) },
	69	{ "t4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[12]) },
	70	{ "t5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[13]) },
	71	{ "t6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[14]) },
	72	{ "t7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[15]) },
	73	{ "s0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[16]) },
	74	{ "s1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[17]) },
	75	{ "s2", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[18]) },
	76	{ "s3", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[19]) },
	77	{ "s4", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[20]) },
	78	{ "s5", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[21]) },
	79	{ "s6", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[22]) },
	80	{ "s7", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[23]) },
	81	{ "t8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[24]) },
	82	{ "t9", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[25]) },
	83	{ "k0", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[26]) },
	84	{ "k1", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[27]) },
	85	{ "gp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[28]) },
	86	{ "sp", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[29]) },
	87	{ "s8", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[30]) },
	88	{ "ra", GDB_SIZEOF_REG, offsetof(struct pt_regs, regs[31]) },
	89	{ "sr", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_status) },
	90	{ "lo", GDB_SIZEOF_REG, offsetof(struct pt_regs, lo) },
	91	{ "hi", GDB_SIZEOF_REG, offsetof(struct pt_regs, hi) },
	92	{ "bad", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_badvaddr) },
	93	{ "cause", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_cause) },
	94	{ "pc", GDB_SIZEOF_REG, offsetof(struct pt_regs, cp0_epc) },
	95	{ "f0", GDB_SIZEOF_REG, 0 },
	96	{ "f1", GDB_SIZEOF_REG, 1 },
	97	{ "f2", GDB_SIZEOF_REG, 2 },
	98	{ "f3", GDB_SIZEOF_REG, 3 },
	99	{ "f4", GDB_SIZEOF_REG, 4 },
	100	{ "f5", GDB_SIZEOF_REG, 5 },
	101	{ "f6", GDB_SIZEOF_REG, 6 },
	102	{ "f7", GDB_SIZEOF_REG, 7 },
	103	{ "f8", GDB_SIZEOF_REG, 8 },
	104	{ "f9", GDB_SIZEOF_REG, 9 },
	105	{ "f10", GDB_SIZEOF_REG, 10 },
	106	{ "f11", GDB_SIZEOF_REG, 11 },
	107	{ "f12", GDB_SIZEOF_REG, 12 },
	108	{ "f13", GDB_SIZEOF_REG, 13 },
	109	{ "f14", GDB_SIZEOF_REG, 14 },
	110	{ "f15", GDB_SIZEOF_REG, 15 },
	111	{ "f16", GDB_SIZEOF_REG, 16 },
	112	{ "f17", GDB_SIZEOF_REG, 17 },
	113	{ "f18", GDB_SIZEOF_REG, 18 },
	114	{ "f19", GDB_SIZEOF_REG, 19 },
	115	{ "f20", GDB_SIZEOF_REG, 20 },
	116	{ "f21", GDB_SIZEOF_REG, 21 },
	117	{ "f22", GDB_SIZEOF_REG, 22 },
	118	{ "f23", GDB_SIZEOF_REG, 23 },
119	{ "f24", GDB_SIZEOF_REG, 24 },
120	{ "f25", GDB_SIZEOF_REG, 25 },
121	{ "f26", GDB_SIZEOF_REG, 26 },
122	{ "f27", GDB_SIZEOF_REG, 27 },
123	{ "f28", GDB_SIZEOF_REG, 28 },
124	{ "f29", GDB_SIZEOF_REG, 29 },
125	{ "f30", GDB_SIZEOF_REG, 30 },
126	{ "f31", GDB_SIZEOF_REG, 31 },
127	{ "fsr", GDB_SIZEOF_REG, 0 },
128	{ "fir", GDB_SIZEOF_REG, 0 },
129	};
130
131	int dbg_set_reg(int regno, void mem, struct pt_regs regs)
132	{
133	int fp_reg;
134
135	if (regno < 0 \|\| regno >= DBG_MAX_REG_NUM)
136	return -EINVAL;
137
138	if (dbg_reg_def[regno].offset != -1 && regno < 38) {
139	memcpy((void *)regs + dbg_reg_def[regno].offset, mem,
140	dbg_reg_def[regno].size);
141	} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
142	/* FP registers 38 -> 69 */
143	if (!(regs->cp0_status & ST0_CU1))
144	return 0;
145	if (regno == 70) {
146	/* Process the fcr31/fsr (register 70) */
147	memcpy((void *)&current->thread.fpu.fcr31, mem,
148	dbg_reg_def[regno].size);
149	goto out_save;
150	} else if (regno == 71) {
151	/* Ignore the fir (register 71) */
152	goto out_save;
153	}
154	fp_reg = dbg_reg_def[regno].offset;
155	memcpy((void *)&current->thread.fpu.fpr[fp_reg], mem,
156	dbg_reg_def[regno].size);
157	out_save:
158	restore_fp(current);
159	}
160
161	return 0;
162	}
163
164	char dbg_get_reg(int regno, void mem, struct pt_regs *regs)
165	{
166	int fp_reg;
167
168	if (regno >= DBG_MAX_REG_NUM \|\| regno < 0)
169	return NULL;
170
171	if (dbg_reg_def[regno].offset != -1 && regno < 38) {
172	/* First 38 registers */
173	memcpy(mem, (void *)regs + dbg_reg_def[regno].offset,
174	dbg_reg_def[regno].size);
175	} else if (current && dbg_reg_def[regno].offset != -1 && regno < 72) {
176	/* FP registers 38 -> 69 */
177	if (!(regs->cp0_status & ST0_CU1))
178	goto out;
179	save_fp(current);
180	if (regno == 70) {
181	/* Process the fcr31/fsr (register 70) */
182	memcpy(mem, (void *)&current->thread.fpu.fcr31,
183	dbg_reg_def[regno].size);
184	goto out;
185	} else if (regno == 71) {
186	/* Ignore the fir (register 71) */
187	memset(mem, 0, dbg_reg_def[regno].size);
188	goto out;
189	}
190	fp_reg = dbg_reg_def[regno].offset;
191	memcpy(mem, (void *)&current->thread.fpu.fpr[fp_reg],
192	dbg_reg_def[regno].size);
193	}
194
195	out:
196	return dbg_reg_def[regno].name;
197
198	}
199
88547001 JW	200	void arch_kgdb_breakpoint(void)
	201	{
	202	__asm__ __volatile__(
	203	".globl breakinst\n\t"
	204	".set\tnoreorder\n\t"
	205	"nop\n"
	206	"breakinst:\tbreak\n\t"
	207	"nop\n\t"
	208	".set\treorder");
	209	}
	210
3cd99ac3	211	void kgdb_call_nmi_hook(void *ignored)
88547001	212	{
6ebda44f LY	213	mm_segment_t old_fs;
	214
	215	old_fs = get_fs();
736706be	216	set_fs(KERNEL_DS);
6ebda44f	217
ab8a6d82	218	kgdb_nmicallback(raw_smp_processor_id(), get_irq_regs());
6ebda44f LY	219
6ebda44f LY	220	set_fs(old_fs);
88547001 JW	221	}
88547001 JW	222
88547001 JW	223	static int compute_signal(int tt)
	224	{
	225	struct hard_trap_info *ht;
	226
	227	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
	228	if (ht->tt == tt)
	229	return ht->signo;
	230
	231	return SIGHUP; /* default for things we don't know about */
	232	}
	233
88547001 JW	234	/*
	235	* Similar to regs_to_gdb_regs() except that process is sleeping and so
	236	* we may not be able to get all the info.
	237	*/
	238	void sleeping_thread_to_gdb_regs(unsigned long gdb_regs, struct task_struct p)
	239	{
	240	int reg;
88547001 JW	241	#if (KGDB_GDB_REG_SIZE == 32)
	242	u32 ptr = (u32 )gdb_regs;
	243	#else
	244	u64 ptr = (u64 )gdb_regs;
	245	#endif
	246
	247	for (reg = 0; reg < 16; reg++)
162b270c	248	*(ptr++) = 0;
88547001 JW	249
88547001 JW	250	/* S0 - S7 */
162b270c JH	251	*(ptr++) = p->thread.reg16;
	252	*(ptr++) = p->thread.reg17;
	253	*(ptr++) = p->thread.reg18;
	254	*(ptr++) = p->thread.reg19;
	255	*(ptr++) = p->thread.reg20;
	256	*(ptr++) = p->thread.reg21;
	257	*(ptr++) = p->thread.reg22;
	258	*(ptr++) = p->thread.reg23;
88547001 JW	259
	260	for (reg = 24; reg < 28; reg++)
	261	*(ptr++) = 0;
	262
	263	/* GP, SP, FP, RA */
162b270c JH	264	*(ptr++) = (long)p;
	265	*(ptr++) = p->thread.reg29;
	266	*(ptr++) = p->thread.reg30;
	267	*(ptr++) = p->thread.reg31;
	268
	269	*(ptr++) = p->thread.cp0_status;
	270
	271	/* lo, hi */
	272	*(ptr++) = 0;
	273	*(ptr++) = 0;
	274
	275	/*
	276	* BadVAddr, Cause
	277	* Ideally these would come from the last exception frame up the stack
	278	* but that requires unwinding, otherwise we can't know much for sure.
	279	*/
	280	*(ptr++) = 0;
	281	*(ptr++) = 0;
	282
	283	/*
	284	* PC
	285	* use return address (RA), i.e. the moment after return from resume()
	286	*/
	287	*(ptr++) = p->thread.reg31;
88547001 JW	288	}
88547001 JW	289
dcc78711 JW	290	void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc)
	291	{
	292	regs->cp0_epc = pc;
	293	}
	294
88547001 JW	295	/*
	296	* Calls linux_debug_hook before the kernel dies. If KGDB is enabled,
	297	* then try to fall into the debugger
	298	*/
	299	static int kgdb_mips_notify(struct notifier_block *self, unsigned long cmd,
	300	void *ptr)
	301	{
	302	struct die_args args = (struct die_args )ptr;
	303	struct pt_regs *regs = args->regs;
	304	int trap = (regs->cp0_cause & 0x7c) >> 2;
6ebda44f	305	mm_segment_t old_fs;
88547001	306
f0a996ee JW	307	#ifdef CONFIG_KPROBES
	308	/*
	309	* Return immediately if the kprobes fault notifier has set
	310	* DIE_PAGE_FAULT.
	311	*/
	312	if (cmd == DIE_PAGE_FAULT)
	313	return NOTIFY_DONE;
	314	#endif /* CONFIG_KPROBES */
	315
eefc3f32	316	/* Userspace events, ignore. */
88547001 JW	317	if (user_mode(regs))
	318	return NOTIFY_DONE;
	319
6ebda44f LY	320	/* Kernel mode. Set correct address limit */
6ebda44f LY	321	old_fs = get_fs();
736706be	322	set_fs(KERNEL_DS);
6ebda44f	323
88547001 JW	324	if (atomic_read(&kgdb_active) != -1)
	325	kgdb_nmicallback(smp_processor_id(), regs);
	326
6ebda44f LY	327	if (kgdb_handle_exception(trap, compute_signal(trap), cmd, regs)) {
6ebda44f LY	328	set_fs(old_fs);
88547001	329	return NOTIFY_DONE;
6ebda44f	330	}
88547001 JW	331
	332	if (atomic_read(&kgdb_setting_breakpoint))
	333	if ((trap == 9) && (regs->cp0_epc == (unsigned long)breakinst))
	334	regs->cp0_epc += 4;
	335
	336	/* In SMP mode, __flush_cache_all does IPI */
	337	local_irq_enable();
	338	__flush_cache_all();
	339
6ebda44f	340	set_fs(old_fs);
88547001 JW	341	return NOTIFY_STOP;
	342	}
	343
5dd11d5d JW	344	#ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
	345	int kgdb_ll_trap(int cmd, const char *str,
	346	struct pt_regs *regs, long err, int trap, int sig)
	347	{
	348	struct die_args args = {
	349	.regs = regs,
	350	.str = str,
	351	.err = err,
70342287	352	.trapnr = trap,
5dd11d5d JW	353	.signr = sig,
	354
	355	};
	356
	357	if (!kgdb_io_module_registered)
	358	return NOTIFY_DONE;
	359
	360	return kgdb_mips_notify(NULL, cmd, &args);
	361	}
	362	#endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
	363
88547001 JW	364	static struct notifier_block kgdb_notifier = {
	365	.notifier_call = kgdb_mips_notify,
	366	};
	367
	368	/*
7aeb48b7	369	* Handle the 'c' command
88547001 JW	370	*/
	371	int kgdb_arch_handle_exception(int vector, int signo, int err_code,
	372	char remcom_in_buffer, char remcom_out_buffer,
	373	struct pt_regs *regs)
	374	{
	375	char *ptr;
	376	unsigned long address;
88547001 JW	377
88547001 JW	378	switch (remcom_in_buffer[0]) {
88547001 JW	379	case 'c':
	380	/* handle the optional parameter */
	381	ptr = &remcom_in_buffer[1];
	382	if (kgdb_hex2long(&ptr, &address))
	383	regs->cp0_epc = address;
	384
88547001 JW	385	return 0;
	386	}
	387
	388	return -1;
	389	}
	390
cc028297	391	const struct kgdb_arch arch_kgdb_ops = {
911b7afd CL	392	#ifdef CONFIG_CPU_BIG_ENDIAN
	393	.gdb_bpt_instr = { spec_op << 2, 0x00, 0x00, break_op },
	394	#else
	395	.gdb_bpt_instr = { break_op, 0x00, 0x00, spec_op << 2 },
	396	#endif
	397	};
88547001	398
88547001 JW	399	int kgdb_arch_init(void)
88547001 JW	400	{
88547001 JW	401	register_die_notifier(&kgdb_notifier);
	402
	403	return 0;
	404	}
	405
	406	/*
	407	* kgdb_arch_exit - Perform any architecture specific uninitalization.
	408	*
	409	* This function will handle the uninitalization of any architecture
	410	* specific callbacks, for dynamic registration and unregistration.
	411	*/
	412	void kgdb_arch_exit(void)
	413	{
	414	unregister_die_notifier(&kgdb_notifier);
	415	}