279 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			279 lines
		
	
	
		
			6.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 *  Originally written by Glenn Engel, Lake Stevens Instrument Division
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 *
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 *  Contributed by HP Systems
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 *
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 *  Modified for Linux/MIPS (and MIPS in general) by Andreas Busse
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 *  Send complaints, suggestions etc. to <andy@waldorf-gmbh.de>
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 *
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 *  Copyright (C) 1995 Andreas Busse
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 *
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 *  Copyright (C) 2003 MontaVista Software Inc.
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 *  Author: Jun Sun, jsun@mvista.com or jsun@junsun.net
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 *
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 *  Copyright (C) 2004-2005 MontaVista Software Inc.
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 *  Author: Manish Lachwani, mlachwani@mvista.com or manish@koffee-break.com
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 *
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 *  Copyright (C) 2007-2008 Wind River Systems, Inc.
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 *  Author/Maintainer: Jason Wessel, jason.wessel@windriver.com
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 *
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 *  This file is licensed under the terms of the GNU General Public License
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 *  version 2. This program is licensed "as is" without any warranty of any
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 *  kind, whether express or implied.
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 */
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#include <linux/ptrace.h>		/* for linux pt_regs struct */
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#include <linux/kgdb.h>
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#include <linux/kdebug.h>
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#include <linux/sched.h>
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#include <linux/smp.h>
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#include <asm/inst.h>
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#include <asm/fpu.h>
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#include <asm/cacheflush.h>
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#include <asm/processor.h>
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#include <asm/sigcontext.h>
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static struct hard_trap_info {
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	unsigned char tt;	/* Trap type code for MIPS R3xxx and R4xxx */
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	unsigned char signo;	/* Signal that we map this trap into */
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} hard_trap_info[] = {
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	{ 6, SIGBUS },		/* instruction bus error */
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	{ 7, SIGBUS },		/* data bus error */
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	{ 9, SIGTRAP },		/* break */
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/*	{ 11, SIGILL },	*/	/* CPU unusable */
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	{ 12, SIGFPE },		/* overflow */
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	{ 13, SIGTRAP },	/* trap */
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	{ 14, SIGSEGV },	/* virtual instruction cache coherency */
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	{ 15, SIGFPE },		/* floating point exception */
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	{ 23, SIGSEGV },	/* watch */
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	{ 31, SIGSEGV },	/* virtual data cache coherency */
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	{ 0, 0}			/* Must be last */
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};
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void arch_kgdb_breakpoint(void)
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{
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	__asm__ __volatile__(
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		".globl breakinst\n\t"
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		".set\tnoreorder\n\t"
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		"nop\n"
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		"breakinst:\tbreak\n\t"
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		"nop\n\t"
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		".set\treorder");
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}
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static void kgdb_call_nmi_hook(void *ignored)
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{
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	kgdb_nmicallback(raw_smp_processor_id(), NULL);
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}
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void kgdb_roundup_cpus(unsigned long flags)
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{
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	local_irq_enable();
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	smp_call_function(kgdb_call_nmi_hook, NULL, 0);
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	local_irq_disable();
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}
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static int compute_signal(int tt)
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{
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	struct hard_trap_info *ht;
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	for (ht = hard_trap_info; ht->tt && ht->signo; ht++)
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		if (ht->tt == tt)
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			return ht->signo;
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	return SIGHUP;		/* default for things we don't know about */
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}
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void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
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{
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	int reg;
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#if (KGDB_GDB_REG_SIZE == 32)
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	u32 *ptr = (u32 *)gdb_regs;
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#else
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	u64 *ptr = (u64 *)gdb_regs;
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#endif
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	for (reg = 0; reg < 32; reg++)
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		*(ptr++) = regs->regs[reg];
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	*(ptr++) = regs->cp0_status;
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	*(ptr++) = regs->lo;
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	*(ptr++) = regs->hi;
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	*(ptr++) = regs->cp0_badvaddr;
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	*(ptr++) = regs->cp0_cause;
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	*(ptr++) = regs->cp0_epc;
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	/* FP REGS */
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	if (!(current && (regs->cp0_status & ST0_CU1)))
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		return;
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	save_fp(current);
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	for (reg = 0; reg < 32; reg++)
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		*(ptr++) = current->thread.fpu.fpr[reg];
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}
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void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
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{
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	int reg;
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#if (KGDB_GDB_REG_SIZE == 32)
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	const u32 *ptr = (u32 *)gdb_regs;
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#else
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	const u64 *ptr = (u64 *)gdb_regs;
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#endif
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	for (reg = 0; reg < 32; reg++)
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		regs->regs[reg] = *(ptr++);
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	regs->cp0_status = *(ptr++);
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	regs->lo = *(ptr++);
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	regs->hi = *(ptr++);
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	regs->cp0_badvaddr = *(ptr++);
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	regs->cp0_cause = *(ptr++);
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	regs->cp0_epc = *(ptr++);
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	/* FP REGS from current */
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	if (!(current && (regs->cp0_status & ST0_CU1)))
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		return;
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	for (reg = 0; reg < 32; reg++)
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		current->thread.fpu.fpr[reg] = *(ptr++);
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	restore_fp(current);
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}
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/*
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 * Similar to regs_to_gdb_regs() except that process is sleeping and so
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 * we may not be able to get all the info.
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 */
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void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, struct task_struct *p)
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{
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	int reg;
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	struct thread_info *ti = task_thread_info(p);
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	unsigned long ksp = (unsigned long)ti + THREAD_SIZE - 32;
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	struct pt_regs *regs = (struct pt_regs *)ksp - 1;
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#if (KGDB_GDB_REG_SIZE == 32)
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	u32 *ptr = (u32 *)gdb_regs;
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#else
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	u64 *ptr = (u64 *)gdb_regs;
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#endif
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	for (reg = 0; reg < 16; reg++)
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		*(ptr++) = regs->regs[reg];
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	/* S0 - S7 */
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	for (reg = 16; reg < 24; reg++)
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		*(ptr++) = regs->regs[reg];
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	for (reg = 24; reg < 28; reg++)
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		*(ptr++) = 0;
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	/* GP, SP, FP, RA */
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	for (reg = 28; reg < 32; reg++)
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		*(ptr++) = regs->regs[reg];
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	*(ptr++) = regs->cp0_status;
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	*(ptr++) = regs->lo;
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	*(ptr++) = regs->hi;
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	*(ptr++) = regs->cp0_badvaddr;
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	*(ptr++) = regs->cp0_cause;
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	*(ptr++) = regs->cp0_epc;
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}
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/*
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 * Calls linux_debug_hook before the kernel dies. If KGDB is enabled,
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 * then try to fall into the debugger
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 */
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static int kgdb_mips_notify(struct notifier_block *self, unsigned long cmd,
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			    void *ptr)
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{
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	struct die_args *args = (struct die_args *)ptr;
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	struct pt_regs *regs = args->regs;
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	int trap = (regs->cp0_cause & 0x7c) >> 2;
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	/* Userpace events, ignore. */
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	if (user_mode(regs))
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		return NOTIFY_DONE;
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	if (atomic_read(&kgdb_active) != -1)
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		kgdb_nmicallback(smp_processor_id(), regs);
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	if (kgdb_handle_exception(trap, compute_signal(trap), 0, regs))
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		return NOTIFY_DONE;
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	if (atomic_read(&kgdb_setting_breakpoint))
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		if ((trap == 9) && (regs->cp0_epc == (unsigned long)breakinst))
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			regs->cp0_epc += 4;
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	/* In SMP mode, __flush_cache_all does IPI */
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	local_irq_enable();
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	__flush_cache_all();
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	return NOTIFY_STOP;
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}
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static struct notifier_block kgdb_notifier = {
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	.notifier_call = kgdb_mips_notify,
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};
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/*
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 * Handle the 's' and 'c' commands
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 */
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int kgdb_arch_handle_exception(int vector, int signo, int err_code,
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			       char *remcom_in_buffer, char *remcom_out_buffer,
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			       struct pt_regs *regs)
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{
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	char *ptr;
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	unsigned long address;
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	int cpu = smp_processor_id();
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	switch (remcom_in_buffer[0]) {
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	case 's':
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	case 'c':
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		/* handle the optional parameter */
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		ptr = &remcom_in_buffer[1];
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		if (kgdb_hex2long(&ptr, &address))
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			regs->cp0_epc = address;
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		atomic_set(&kgdb_cpu_doing_single_step, -1);
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		if (remcom_in_buffer[0] == 's')
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			atomic_set(&kgdb_cpu_doing_single_step, cpu);
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		return 0;
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	}
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	return -1;
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}
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struct kgdb_arch arch_kgdb_ops;
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/*
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 * We use kgdb_early_setup so that functions we need to call now don't
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 * cause trouble when called again later.
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 */
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int kgdb_arch_init(void)
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{
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	union mips_instruction insn = {
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		.r_format = {
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			.opcode = spec_op,
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			.func   = break_op,
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		}
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	};
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	memcpy(arch_kgdb_ops.gdb_bpt_instr, insn.byte, BREAK_INSTR_SIZE);
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	register_die_notifier(&kgdb_notifier);
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	return 0;
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}
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/*
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 *	kgdb_arch_exit - Perform any architecture specific uninitalization.
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 *
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 *	This function will handle the uninitalization of any architecture
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 *	specific callbacks, for dynamic registration and unregistration.
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 */
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void kgdb_arch_exit(void)
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{
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	unregister_die_notifier(&kgdb_notifier);
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}
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