/*
* 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>
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 */
};
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 */
}
void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
int reg;
#if (KGDB_GDB_REG_SIZE == 32)
u32 *ptr = (u32 *)gdb_regs;
#else
u64 *ptr = (u64 *)gdb_regs;
#endif
for (reg = 0; 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;
/* FP REGS */
if (!(current && (regs->cp0_status & ST0_CU1)))
return;
save_fp(current);
for (reg = 0; reg < 32; reg++)
*(ptr++) = current->thread.fpu.fpr[reg];
}
void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs)
{
int reg;
#if (KGDB_GDB_REG_SIZE == 32)
const u32 *ptr = (u32 *)gdb_regs;
#else
const u64 *ptr = (u64 *)gdb_regs;
#endif
for (reg = 0; reg < 32; reg++)
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 = *(ptr++);
/* FP REGS from current */
if (!(current && (regs->cp0_status & ST0_CU1)))
return;
for (reg = 0; reg < 32; reg++)
current->thread.fpu.fpr[reg] = *(ptr++);
restore_fp(current);
}
/*
* 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;
}
/*
* 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;
/* Userpace 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), 0, 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;
}
static struct notifier_block kgdb_notifier = {
.notifier_call = kgdb_mips_notify,
};
/*
* Handle the 's' and 'c' commands
*/
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;
int cpu = smp_processor_id();
switch (remcom_in_buffer[0]) {
case 's':
case 'c':
/* handle the optional parameter */
ptr = &remcom_in_buffer[1];
if (kgdb_hex2long(&ptr, &address))
regs->cp0_epc = address;
atomic_set(&kgdb_cpu_doing_single_step, -1);
if (remcom_in_buffer[0] == 's')
atomic_set(&kgdb_cpu_doing_single_step, cpu);
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);
}
