/*

   *  linux/arch/cris/traps.c
   *

   *  Here we handle the break vectors not used by the system call
   *  mechanism, as well as some general stack/register dumping

   *  things.

   *
   *  Copyright (C) 2000-2007 Axis Communications AB

   *
   *  Authors:   Bjorn Wesen

   *             Hans-Peter Nilsson

   *
   */
  
  #include <linux/init.h>
  #include <linux/module.h>

  #include <asm/pgtable.h>
  #include <asm/uaccess.h>

  extern void arch_enable_nmi(void);
  extern void stop_watchdog(void);
  extern void reset_watchdog(void);
  extern void show_registers(struct pt_regs *regs);
  
  #ifdef CONFIG_DEBUG_BUGVERBOSE
  extern void handle_BUG(struct pt_regs *regs);
  #else
  #define handle_BUG(regs)
  #endif

  static int kstack_depth_to_print = 24;

  void (*nmi_handler)(struct pt_regs *);

  void
  show_trace(unsigned long *stack)

  {
  	unsigned long addr, module_start, module_end;
  	extern char _stext, _etext;
  	int i;

  	printk("
  Call Trace: ");

  	i = 1;
  	module_start = VMALLOC_START;
  	module_end = VMALLOC_END;

  	while (((long)stack & (THREAD_SIZE-1)) != 0) {
  		if (__get_user(addr, stack)) {

  			/* This message matches "failing address" marked
  			   s390 in ksymoops, so lines containing it will
  			   not be filtered out by ksymoops.  */

  			printk("Failing address 0x%lx
  ", (unsigned long)stack);

  			break;
  		}
  		stack++;

  		/*
  		 * If the address is either in the text segment of the
  		 * kernel, or in the region which contains vmalloc'ed
  		 * memory, it *may* be the address of a calling
  		 * routine; if so, print it so that someone tracing
  		 * down the cause of the crash will be able to figure
  		 * out the call path that was taken.
  		 */
  		if (((addr >= (unsigned long)&_stext) &&
  		     (addr <= (unsigned long)&_etext)) ||
  		    ((addr >= module_start) && (addr <= module_end))) {
  			if (i && ((i % 8) == 0))
  				printk("
         ");
  			printk("[<%08lx>] ", addr);
  			i++;
  		}
  	}

  }
  
  /*
   * These constants are for searching for possible module text
   * segments. MODULE_RANGE is a guess of how much space is likely
   * to be vmalloced.
   */
  
  #define MODULE_RANGE (8*1024*1024)
  
  /*
   * The output (format, strings and order) is adjusted to be usable with
   * ksymoops-2.4.1 with some necessary CRIS-specific patches.  Please don't
   * change it unless you're serious about adjusting ksymoops and syncing
   * with the ksymoops maintainer.
   */

  void

  show_stack(struct task_struct *task, unsigned long *sp)
  {

  	unsigned long *stack, addr;
  	int i;

  
  	/*
  	 * debugging aid: "show_stack(NULL);" prints a
  	 * back trace.
  	 */

  	if (sp == NULL) {

  		if (task)
  			sp = (unsigned long*)task->thread.ksp;
  		else
  			sp = (unsigned long*)rdsp();
  	}

  	stack = sp;

  	printk("
  Stack from %08lx:
         ", (unsigned long)stack);
  	for (i = 0; i < kstack_depth_to_print; i++) {
  		if (((long)stack & (THREAD_SIZE-1)) == 0)
  			break;
  		if (i && ((i % 8) == 0))
  			printk("
         ");
  		if (__get_user(addr, stack)) {

  			/* This message matches "failing address" marked
  			   s390 in ksymoops, so lines containing it will
  			   not be filtered out by ksymoops.  */

  			printk("Failing address 0x%lx
  ", (unsigned long)stack);

  			break;
  		}
  		stack++;

  		printk("%08lx ", addr);
  	}

  	show_trace(sp);
  }

  #if 0
  /* displays a short stack trace */

  int
  show_stack(void)

  {

  	unsigned long *sp = (unsigned long *)rdusp();
  	int i;
  
  	printk("Stack dump [0x%08lx]:
  ", (unsigned long)sp);
  	for (i = 0; i < 16; i++)
  		printk("sp + %d: 0x%08lx
  ", i*4, sp[i]);
  	return 0;

  }

  #endif

  void
  dump_stack(void)

  {

  	show_stack(NULL, NULL);
  }
  EXPORT_SYMBOL(dump_stack);
  
  void
  set_nmi_handler(void (*handler)(struct pt_regs *))
  {
  	nmi_handler = handler;
  	arch_enable_nmi();

  }
  
  #ifdef CONFIG_DEBUG_NMI_OOPS

  void
  oops_nmi_handler(struct pt_regs *regs)

  {

  	stop_watchdog();
  	oops_in_progress = 1;
  	printk("NMI!
  ");
  	show_registers(regs);
  	oops_in_progress = 0;

  }

  static int __init
  oops_nmi_register(void)

  {

  	set_nmi_handler(oops_nmi_handler);
  	return 0;

  }
  
  __initcall(oops_nmi_register);
  
  #endif

  /*
   * This gets called from entry.S when the watchdog has bitten. Show something

   * similar to an Oops dump, and if the kernel is configured to be a nice

   * doggy, then halt instead of reboot.
   */
  void
  watchdog_bite_hook(struct pt_regs *regs)

  {

  #ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
  	local_irq_disable();
  	stop_watchdog();
  	show_registers(regs);
  
  	while (1)
  		; /* Do nothing. */
  #else
  	show_registers(regs);

  #endif

  }

  /* This is normally the Oops function. */
  void
  die_if_kernel(const char *str, struct pt_regs *regs, long err)

  {

  	if (user_mode(regs))
  		return;

  #ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
  	/*
  	 * This printout might take too long and could trigger
  	 * the watchdog normally. If NICE_DOGGY is set, simply
  	 * stop the watchdog during the printout.
  	 */
  	stop_watchdog();
  #endif

  	handle_BUG(regs);
  
  	printk("%s: %04lx
  ", str, err & 0xffff);
  
  	show_registers(regs);
  
  	oops_in_progress = 0;
  
  #ifdef CONFIG_ETRAX_WATCHDOG_NICE_DOGGY
  	reset_watchdog();
  #endif
  	do_exit(SIGSEGV);

  }

  void __init
  trap_init(void)

  {

  	/* Nothing needs to be done */

  }