[deliverable/linux.git] / arch / xtensa / kernel / traps.c

/*
 * arch/xtensa/kernel/traps.c
 *
 * Exception handling.
 *
 * Derived from code with the following copyrights:
 * Copyright (C) 1994 - 1999 by Ralf Baechle
 * Modified for R3000 by Paul M. Antoine, 1995, 1996
 * Complete output from die() by Ulf Carlsson, 1998
 * Copyright (C) 1999 Silicon Graphics, Inc.
 *
 * Essentially rewritten for the Xtensa architecture port.
 *
 * Copyright (C) 2001 - 2005 Tensilica Inc.
 *
 * Joe Taylor	<joe@tensilica.com, joetylr@yahoo.com>
 * Chris Zankel	<chris@zankel.net>
 * Marc Gauthier<marc@tensilica.com, marc@alumni.uwaterloo.ca>
 * Kevin Chea
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/stringify.h>
#include <linux/kallsyms.h>
#include <linux/delay.h>

#include <asm/ptrace.h>
#include <asm/timex.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/processor.h>

#ifdef CONFIG_KGDB
extern int gdb_enter;
extern int return_from_debug_flag;
#endif

/*
 * Machine specific interrupt handlers
 */

extern void kernel_exception(void);
extern void user_exception(void);

extern void fast_syscall_kernel(void);
extern void fast_syscall_user(void);
extern void fast_alloca(void);
extern void fast_unaligned(void);
extern void fast_second_level_miss(void);
extern void fast_store_prohibited(void);
extern void fast_coprocessor(void);

extern void do_illegal_instruction (struct pt_regs*);
extern void do_interrupt (struct pt_regs*);
extern void do_unaligned_user (struct pt_regs*);
extern void do_multihit (struct pt_regs*, unsigned long);
extern void do_page_fault (struct pt_regs*, unsigned long);
extern void do_debug (struct pt_regs*);
extern void system_call (struct pt_regs*);

/*
 * The vector table must be preceded by a save area (which
 * implies it must be in RAM, unless one places RAM immediately
 * before a ROM and puts the vector at the start of the ROM (!))
 */

#define KRNL		0x01
#define USER		0x02

#define COPROCESSOR(x)							\
{ EXCCAUSE_COPROCESSOR ## x ## _DISABLED, USER, fast_coprocessor }

typedef struct {
	int cause;
	int fast;
	void* handler;
} dispatch_init_table_t;

static dispatch_init_table_t __initdata dispatch_init_table[] = {

{ EXCCAUSE_ILLEGAL_INSTRUCTION,	0,	   do_illegal_instruction},
{ EXCCAUSE_SYSTEM_CALL,		KRNL,	   fast_syscall_kernel },
{ EXCCAUSE_SYSTEM_CALL,		USER,	   fast_syscall_user },
{ EXCCAUSE_SYSTEM_CALL,		0,	   system_call },
/* EXCCAUSE_INSTRUCTION_FETCH unhandled */
/* EXCCAUSE_LOAD_STORE_ERROR unhandled*/
{ EXCCAUSE_LEVEL1_INTERRUPT,	0,	   do_interrupt },
{ EXCCAUSE_ALLOCA,		USER|KRNL, fast_alloca },
/* EXCCAUSE_INTEGER_DIVIDE_BY_ZERO unhandled */
/* EXCCAUSE_PRIVILEGED unhandled */
#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
#ifdef CONFIG_UNALIGNED_USER
{ EXCCAUSE_UNALIGNED,		USER,	   fast_unaligned },
#else
{ EXCCAUSE_UNALIGNED,		0,	   do_unaligned_user },
#endif
{ EXCCAUSE_UNALIGNED,		KRNL,	   fast_unaligned },
#endif
{ EXCCAUSE_ITLB_MISS,		0,	   do_page_fault },
{ EXCCAUSE_ITLB_MISS,		USER|KRNL, fast_second_level_miss},
{ EXCCAUSE_ITLB_MULTIHIT,		0,	   do_multihit },
{ EXCCAUSE_ITLB_PRIVILEGE,	0,	   do_page_fault },
/* EXCCAUSE_SIZE_RESTRICTION unhandled */
{ EXCCAUSE_FETCH_CACHE_ATTRIBUTE,	0,	   do_page_fault },
{ EXCCAUSE_DTLB_MISS,		USER|KRNL, fast_second_level_miss},
{ EXCCAUSE_DTLB_MISS,		0,	   do_page_fault },
{ EXCCAUSE_DTLB_MULTIHIT,		0,	   do_multihit },
{ EXCCAUSE_DTLB_PRIVILEGE,	0,	   do_page_fault },
/* EXCCAUSE_DTLB_SIZE_RESTRICTION unhandled */
{ EXCCAUSE_STORE_CACHE_ATTRIBUTE,	USER|KRNL, fast_store_prohibited },
{ EXCCAUSE_STORE_CACHE_ATTRIBUTE,	0,	   do_page_fault },
{ EXCCAUSE_LOAD_CACHE_ATTRIBUTE,	0,	   do_page_fault },
/* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */
#if XTENSA_HAVE_COPROCESSOR(0)
COPROCESSOR(0),
#endif
#if XTENSA_HAVE_COPROCESSOR(1)
COPROCESSOR(1),
#endif
#if XTENSA_HAVE_COPROCESSOR(2)
COPROCESSOR(2),
#endif
#if XTENSA_HAVE_COPROCESSOR(3)
COPROCESSOR(3),
#endif
#if XTENSA_HAVE_COPROCESSOR(4)
COPROCESSOR(4),
#endif
#if XTENSA_HAVE_COPROCESSOR(5)
COPROCESSOR(5),
#endif
#if XTENSA_HAVE_COPROCESSOR(6)
COPROCESSOR(6),
#endif
#if XTENSA_HAVE_COPROCESSOR(7)
COPROCESSOR(7),
#endif
{ EXCCAUSE_MAPPED_DEBUG,		0,		do_debug },
{ -1, -1, 0 }

};

/* The exception table <exc_table> serves two functions:
 * 1. it contains three dispatch tables (fast_user, fast_kernel, default-c)
 * 2. it is a temporary memory buffer for the exception handlers.
 */

unsigned long exc_table[EXC_TABLE_SIZE/4];

void die(const char*, struct pt_regs*, long);

static inline void
__die_if_kernel(const char *str, struct pt_regs *regs, long err)
{
	if (!user_mode(regs))
		die(str, regs, err);
}

/*
 * Unhandled Exceptions. Kill user task or panic if in kernel space.
 */

void do_unhandled(struct pt_regs *regs, unsigned long exccause)
{
	__die_if_kernel("Caught unhandled exception - should not happen",
	    		regs, SIGKILL);

	/* If in user mode, send SIGILL signal to current process */
	printk("Caught unhandled exception in '%s' "
	       "(pid = %d, pc = %#010lx) - should not happen\n"
	       "\tEXCCAUSE is %ld\n",
	       current->comm, task_pid_nr(current), regs->pc, exccause);
	force_sig(SIGILL, current);
}

/*
 * Multi-hit exception. This if fatal!
 */

void do_multihit(struct pt_regs *regs, unsigned long exccause)
{
	die("Caught multihit exception", regs, SIGKILL);
}

/*
 * Level-1 interrupt.
 * We currently have no priority encoding.
 */

unsigned long ignored_level1_interrupts;
extern void do_IRQ(int, struct pt_regs *);

void do_interrupt (struct pt_regs *regs)
{
	unsigned long intread = get_sr (INTREAD);
	unsigned long intenable = get_sr (INTENABLE);
	int i, mask;

	/* Handle all interrupts (no priorities).
	 * (Clear the interrupt before processing, in case it's
	 *  edge-triggered or software-generated)
	 */

	for (i=0, mask = 1; i < XCHAL_NUM_INTERRUPTS; i++, mask <<= 1) {
		if (mask & (intread & intenable)) {
			set_sr (mask, INTCLEAR);
			do_IRQ (i,regs);
		}
	}
}

/*
 * Illegal instruction. Fatal if in kernel space.
 */

void
do_illegal_instruction(struct pt_regs *regs)
{
	__die_if_kernel("Illegal instruction in kernel", regs, SIGKILL);

	/* If in user mode, send SIGILL signal to current process. */

	printk("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n",
	    current->comm, task_pid_nr(current), regs->pc);
	force_sig(SIGILL, current);
}


/*
 * Handle unaligned memory accesses from user space. Kill task.
 *
 * If CONFIG_UNALIGNED_USER is not set, we don't allow unaligned memory
 * accesses causes from user space.
 */

#if XCHAL_UNALIGNED_LOAD_EXCEPTION || XCHAL_UNALIGNED_STORE_EXCEPTION
#ifndef CONFIG_UNALIGNED_USER
void
do_unaligned_user (struct pt_regs *regs)
{
	siginfo_t info;

	__die_if_kernel("Unhandled unaligned exception in kernel",
	    		regs, SIGKILL);

	current->thread.bad_vaddr = regs->excvaddr;
	current->thread.error_code = -3;
	printk("Unaligned memory access to %08lx in '%s' "
	       "(pid = %d, pc = %#010lx)\n",
	       regs->excvaddr, current->comm, task_pid_nr(current), regs->pc);
	info.si_signo = SIGBUS;
	info.si_errno = 0;
	info.si_code = BUS_ADRALN;
	info.si_addr = (void *) regs->excvaddr;
	force_sig_info(SIGSEGV, &info, current);

}
#endif
#endif

void
do_debug(struct pt_regs *regs)
{
#ifdef CONFIG_KGDB
	/* If remote debugging is configured AND enabled, we give control to
	 * kgdb.  Otherwise, we fall through, perhaps giving control to the
	 * native debugger.
	 */

	if (gdb_enter) {
		extern void gdb_handle_exception(struct pt_regs *);
		gdb_handle_exception(regs);
		return_from_debug_flag = 1;
		return;
	}
#endif

	__die_if_kernel("Breakpoint in kernel", regs, SIGKILL);

	/* If in user mode, send SIGTRAP signal to current process */

	force_sig(SIGTRAP, current);
}


/*
 * Initialize dispatch tables.
 *
 * The exception vectors are stored compressed the __init section in the
 * dispatch_init_table. This function initializes the following three tables
 * from that compressed table:
 * - fast user		first dispatch table for user exceptions
 * - fast kernel	first dispatch table for kernel exceptions
 * - default C-handler	C-handler called by the default fast handler.
 *
 * See vectors.S for more details.
 */

#define set_handler(idx,handler) (exc_table[idx] = (unsigned long) (handler))

void __init trap_init(void)
{
	int i;

	/* Setup default vectors. */

	for(i = 0; i < 64; i++) {
		set_handler(EXC_TABLE_FAST_USER/4   + i, user_exception);
		set_handler(EXC_TABLE_FAST_KERNEL/4 + i, kernel_exception);
		set_handler(EXC_TABLE_DEFAULT/4 + i, do_unhandled);
	}

	/* Setup specific handlers. */

	for(i = 0; dispatch_init_table[i].cause >= 0; i++) {

		int fast = dispatch_init_table[i].fast;
		int cause = dispatch_init_table[i].cause;
		void *handler = dispatch_init_table[i].handler;

		if (fast == 0)
			set_handler (EXC_TABLE_DEFAULT/4 + cause, handler);
		if (fast && fast & USER)
			set_handler (EXC_TABLE_FAST_USER/4 + cause, handler);
		if (fast && fast & KRNL)
			set_handler (EXC_TABLE_FAST_KERNEL/4 + cause, handler);
	}

	/* Initialize EXCSAVE_1 to hold the address of the exception table. */

	i = (unsigned long)exc_table;
	__asm__ __volatile__("wsr  %0, "__stringify(EXCSAVE_1)"\n" : : "a" (i));
}

/*
 * This function dumps the current valid window frame and other base registers.
 */

void show_regs(struct pt_regs * regs)
{
	int i, wmask;

	wmask = regs->wmask & ~1;

	for (i = 0; i < 16; i++) {
		if ((i % 8) == 0)
			printk ("\n" KERN_INFO "a%02d: ", i);
		printk("%08lx ", regs->areg[i]);
	}
	printk("\n");

	printk("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n",
	       regs->pc, regs->ps, regs->depc, regs->excvaddr);
	printk("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n",
	       regs->lbeg, regs->lend, regs->lcount, regs->sar);
	if (user_mode(regs))
		printk("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n",
		       regs->windowbase, regs->windowstart, regs->wmask,
		       regs->syscall);
}

void show_trace(struct task_struct *task, unsigned long *sp)
{
	unsigned long a0, a1, pc;
	unsigned long sp_start, sp_end;

	a1 = (unsigned long)sp;

	if (a1 == 0)
		__asm__ __volatile__ ("mov %0, a1\n" : "=a"(a1));


	sp_start = a1 & ~(THREAD_SIZE-1);
	sp_end = sp_start + THREAD_SIZE;

	printk("Call Trace:");
#ifdef CONFIG_KALLSYMS
	printk("\n");
#endif
	spill_registers();

	while (a1 > sp_start && a1 < sp_end) {
		sp = (unsigned long*)a1;

		a0 = *(sp - 4);
		a1 = *(sp - 3);

		if (a1 <= (unsigned long) sp)
			break;

		pc = MAKE_PC_FROM_RA(a0, a1);

		if (kernel_text_address(pc)) {
			printk(" [<%08lx>] ", pc);
			print_symbol("%s\n", pc);
		}
	}
	printk("\n");
}

/*
 * This routine abuses get_user()/put_user() to reference pointers
 * with at least a bit of error checking ...
 */

static int kstack_depth_to_print = 24;

void show_stack(struct task_struct *task, unsigned long *sp)
{
	int i = 0;
	unsigned long *stack;

	if (sp == 0)
		__asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp));

 	stack = sp;

	printk("\nStack: ");

	for (i = 0; i < kstack_depth_to_print; i++) {
		if (kstack_end(sp))
			break;
		if (i && ((i % 8) == 0))
			printk("\n       ");
		printk("%08lx ", *sp++);
	}
	printk("\n");
	show_trace(task, stack);
}

void dump_stack(void)
{
	show_stack(current, NULL);
}

EXPORT_SYMBOL(dump_stack);


void show_code(unsigned int *pc)
{
	long i;

	printk("\nCode:");

	for(i = -3 ; i < 6 ; i++) {
		unsigned long insn;
		if (__get_user(insn, pc + i)) {
			printk(" (Bad address in pc)\n");
			break;
		}
		printk("%c%08lx%c",(i?' ':'<'),insn,(i?' ':'>'));
	}
}

DEFINE_SPINLOCK(die_lock);

void die(const char * str, struct pt_regs * regs, long err)
{
	static int die_counter;
	int nl = 0;

	console_verbose();
	spin_lock_irq(&die_lock);

	printk("%s: sig: %ld [#%d]\n", str, err, ++die_counter);
#ifdef CONFIG_PREEMPT
	printk("PREEMPT ");
	nl = 1;
#endif
	if (nl)
		printk("\n");
	show_regs(regs);
	if (!user_mode(regs))
		show_stack(NULL, (unsigned long*)regs->areg[1]);

	add_taint(TAINT_DIE);
	spin_unlock_irq(&die_lock);

	if (in_interrupt())
		panic("Fatal exception in interrupt");

	if (panic_on_oops)
		panic("Fatal exception");

	do_exit(err);
}
Commit	Line	Data
5a0015d6 CZ	1	/*
	2	* arch/xtensa/kernel/traps.c
	3	*
	4	* Exception handling.
	5	*
	6	* Derived from code with the following copyrights:
	7	* Copyright (C) 1994 - 1999 by Ralf Baechle
	8	* Modified for R3000 by Paul M. Antoine, 1995, 1996
	9	* Complete output from die() by Ulf Carlsson, 1998
	10	* Copyright (C) 1999 Silicon Graphics, Inc.
	11	*
	12	* Essentially rewritten for the Xtensa architecture port.
	13	*
	14	* Copyright (C) 2001 - 2005 Tensilica Inc.
	15	*
	16	* Joe Taylor <joe@tensilica.com, joetylr@yahoo.com>
	17	* Chris Zankel <chris@zankel.net>
	18	* Marc Gauthier<marc@tensilica.com, marc@alumni.uwaterloo.ca>
	19	* Kevin Chea
	20	*
	21	* This file is subject to the terms and conditions of the GNU General Public
	22	* License. See the file "COPYING" in the main directory of this archive
	23	* for more details.
	24	*/
	25
	26	#include <linux/kernel.h>
	27	#include <linux/sched.h>
	28	#include <linux/init.h>
	29	#include <linux/module.h>
	30	#include <linux/stringify.h>
	31	#include <linux/kallsyms.h>
5c888d53	32	#include <linux/delay.h>
5a0015d6 CZ	33
	34	#include <asm/ptrace.h>
	35	#include <asm/timex.h>
	36	#include <asm/uaccess.h>
	37	#include <asm/pgtable.h>
	38	#include <asm/processor.h>
	39
	40	#ifdef CONFIG_KGDB
	41	extern int gdb_enter;
	42	extern int return_from_debug_flag;
	43	#endif
	44
	45	/*
	46	* Machine specific interrupt handlers
	47	*/
	48
	49	extern void kernel_exception(void);
	50	extern void user_exception(void);
	51
	52	extern void fast_syscall_kernel(void);
	53	extern void fast_syscall_user(void);
	54	extern void fast_alloca(void);
	55	extern void fast_unaligned(void);
	56	extern void fast_second_level_miss(void);
	57	extern void fast_store_prohibited(void);
	58	extern void fast_coprocessor(void);
	59
	60	extern void do_illegal_instruction (struct pt_regs*);
	61	extern void do_interrupt (struct pt_regs*);
	62	extern void do_unaligned_user (struct pt_regs*);
	63	extern void do_multihit (struct pt_regs*, unsigned long);
	64	extern void do_page_fault (struct pt_regs*, unsigned long);
	65	extern void do_debug (struct pt_regs*);
	66	extern void system_call (struct pt_regs*);
	67
	68	/*
	69	* The vector table must be preceded by a save area (which
	70	* implies it must be in RAM, unless one places RAM immediately
	71	* before a ROM and puts the vector at the start of the ROM (!))
	72	*/
	73
	74	#define KRNL 0x01
	75	#define USER 0x02
	76
	77	#define COPROCESSOR(x) \
173d6681	78	{ EXCCAUSE_COPROCESSOR ## x ## _DISABLED, USER, fast_coprocessor }
5a0015d6 CZ	79
	80	typedef struct {
	81	int cause;
	82	int fast;
	83	void* handler;
	84	} dispatch_init_table_t;
	85
b91dc336	86	static dispatch_init_table_t __initdata dispatch_init_table[] = {
5a0015d6	87
173d6681 CZ	88	{ EXCCAUSE_ILLEGAL_INSTRUCTION, 0, do_illegal_instruction},
	89	{ EXCCAUSE_SYSTEM_CALL, KRNL, fast_syscall_kernel },
	90	{ EXCCAUSE_SYSTEM_CALL, USER, fast_syscall_user },
	91	{ EXCCAUSE_SYSTEM_CALL, 0, system_call },
	92	/* EXCCAUSE_INSTRUCTION_FETCH unhandled */
	93	/* EXCCAUSE_LOAD_STORE_ERROR unhandled*/
	94	{ EXCCAUSE_LEVEL1_INTERRUPT, 0, do_interrupt },
	95	{ EXCCAUSE_ALLOCA, USER\|KRNL, fast_alloca },
	96	/* EXCCAUSE_INTEGER_DIVIDE_BY_ZERO unhandled */
	97	/* EXCCAUSE_PRIVILEGED unhandled */
5a0015d6 CZ	98	#if XCHAL_UNALIGNED_LOAD_EXCEPTION \|\| XCHAL_UNALIGNED_STORE_EXCEPTION
5a0015d6 CZ	99	#ifdef CONFIG_UNALIGNED_USER
173d6681	100	{ EXCCAUSE_UNALIGNED, USER, fast_unaligned },
5a0015d6	101	#else
173d6681	102	{ EXCCAUSE_UNALIGNED, 0, do_unaligned_user },
5a0015d6	103	#endif
173d6681	104	{ EXCCAUSE_UNALIGNED, KRNL, fast_unaligned },
5a0015d6	105	#endif
173d6681 CZ	106	{ EXCCAUSE_ITLB_MISS, 0, do_page_fault },
	107	{ EXCCAUSE_ITLB_MISS, USER\|KRNL, fast_second_level_miss},
	108	{ EXCCAUSE_ITLB_MULTIHIT, 0, do_multihit },
	109	{ EXCCAUSE_ITLB_PRIVILEGE, 0, do_page_fault },
	110	/* EXCCAUSE_SIZE_RESTRICTION unhandled */
	111	{ EXCCAUSE_FETCH_CACHE_ATTRIBUTE, 0, do_page_fault },
	112	{ EXCCAUSE_DTLB_MISS, USER\|KRNL, fast_second_level_miss},
	113	{ EXCCAUSE_DTLB_MISS, 0, do_page_fault },
	114	{ EXCCAUSE_DTLB_MULTIHIT, 0, do_multihit },
	115	{ EXCCAUSE_DTLB_PRIVILEGE, 0, do_page_fault },
	116	/* EXCCAUSE_DTLB_SIZE_RESTRICTION unhandled */
	117	{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, USER\|KRNL, fast_store_prohibited },
	118	{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, 0, do_page_fault },
	119	{ EXCCAUSE_LOAD_CACHE_ATTRIBUTE, 0, do_page_fault },
5a0015d6	120	/* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */
c658eac6	121	#if XTENSA_HAVE_COPROCESSOR(0)
5a0015d6 CZ	122	COPROCESSOR(0),
5a0015d6 CZ	123	#endif
c658eac6	124	#if XTENSA_HAVE_COPROCESSOR(1)
5a0015d6 CZ	125	COPROCESSOR(1),
5a0015d6 CZ	126	#endif
c658eac6	127	#if XTENSA_HAVE_COPROCESSOR(2)
5a0015d6 CZ	128	COPROCESSOR(2),
5a0015d6 CZ	129	#endif
c658eac6	130	#if XTENSA_HAVE_COPROCESSOR(3)
5a0015d6 CZ	131	COPROCESSOR(3),
5a0015d6 CZ	132	#endif
c658eac6	133	#if XTENSA_HAVE_COPROCESSOR(4)
5a0015d6 CZ	134	COPROCESSOR(4),
5a0015d6 CZ	135	#endif
c658eac6	136	#if XTENSA_HAVE_COPROCESSOR(5)
5a0015d6 CZ	137	COPROCESSOR(5),
5a0015d6 CZ	138	#endif
c658eac6	139	#if XTENSA_HAVE_COPROCESSOR(6)
5a0015d6 CZ	140	COPROCESSOR(6),
5a0015d6 CZ	141	#endif
c658eac6	142	#if XTENSA_HAVE_COPROCESSOR(7)
5a0015d6 CZ	143	COPROCESSOR(7),
	144	#endif
	145	{ EXCCAUSE_MAPPED_DEBUG, 0, do_debug },
	146	{ -1, -1, 0 }
	147
	148	};
	149
	150	/* The exception table <exc_table> serves two functions:
	151	* 1. it contains three dispatch tables (fast_user, fast_kernel, default-c)
	152	* 2. it is a temporary memory buffer for the exception handlers.
	153	*/
	154
	155	unsigned long exc_table[EXC_TABLE_SIZE/4];
	156
	157	void die(const char, struct pt_regs, long);
	158
	159	static inline void
	160	__die_if_kernel(const char str, struct pt_regs regs, long err)
	161	{
	162	if (!user_mode(regs))
	163	die(str, regs, err);
	164	}
	165
	166	/*
	167	* Unhandled Exceptions. Kill user task or panic if in kernel space.
	168	*/
	169
	170	void do_unhandled(struct pt_regs *regs, unsigned long exccause)
	171	{
	172	__die_if_kernel("Caught unhandled exception - should not happen",
	173	regs, SIGKILL);
	174
	175	/* If in user mode, send SIGILL signal to current process */
	176	printk("Caught unhandled exception in '%s' "
	177	"(pid = %d, pc = %#010lx) - should not happen\n"
	178	"\tEXCCAUSE is %ld\n",
19c5870c	179	current->comm, task_pid_nr(current), regs->pc, exccause);
5a0015d6 CZ	180	force_sig(SIGILL, current);
	181	}
	182
	183	/*
	184	* Multi-hit exception. This if fatal!
	185	*/
	186
	187	void do_multihit(struct pt_regs *regs, unsigned long exccause)
	188	{
	189	die("Caught multihit exception", regs, SIGKILL);
	190	}
	191
	192	/*
	193	* Level-1 interrupt.
	194	* We currently have no priority encoding.
	195	*/
	196
	197	unsigned long ignored_level1_interrupts;
	198	extern void do_IRQ(int, struct pt_regs *);
	199
	200	void do_interrupt (struct pt_regs *regs)
	201	{
	202	unsigned long intread = get_sr (INTREAD);
	203	unsigned long intenable = get_sr (INTENABLE);
	204	int i, mask;
	205
	206	/* Handle all interrupts (no priorities).
	207	* (Clear the interrupt before processing, in case it's
	208	* edge-triggered or software-generated)
	209	*/
	210
	211	for (i=0, mask = 1; i < XCHAL_NUM_INTERRUPTS; i++, mask <<= 1) {
	212	if (mask & (intread & intenable)) {
	213	set_sr (mask, INTCLEAR);
	214	do_IRQ (i,regs);
	215	}
	216	}
	217	}
	218
	219	/*
	220	* Illegal instruction. Fatal if in kernel space.
	221	*/
	222
	223	void
	224	do_illegal_instruction(struct pt_regs *regs)
	225	{
	226	__die_if_kernel("Illegal instruction in kernel", regs, SIGKILL);
	227
	228	/* If in user mode, send SIGILL signal to current process. */
	229
	230	printk("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n",
19c5870c	231	current->comm, task_pid_nr(current), regs->pc);
5a0015d6 CZ	232	force_sig(SIGILL, current);
	233	}
	234
	235
	236	/*
	237	* Handle unaligned memory accesses from user space. Kill task.
	238	*
	239	* If CONFIG_UNALIGNED_USER is not set, we don't allow unaligned memory
	240	* accesses causes from user space.
	241	*/
	242
	243	#if XCHAL_UNALIGNED_LOAD_EXCEPTION \|\| XCHAL_UNALIGNED_STORE_EXCEPTION
	244	#ifndef CONFIG_UNALIGNED_USER
	245	void
	246	do_unaligned_user (struct pt_regs *regs)
	247	{
	248	siginfo_t info;
	249
	250	__die_if_kernel("Unhandled unaligned exception in kernel",
	251	regs, SIGKILL);
	252
	253	current->thread.bad_vaddr = regs->excvaddr;
	254	current->thread.error_code = -3;
	255	printk("Unaligned memory access to %08lx in '%s' "
	256	"(pid = %d, pc = %#010lx)\n",
19c5870c	257	regs->excvaddr, current->comm, task_pid_nr(current), regs->pc);
5a0015d6 CZ	258	info.si_signo = SIGBUS;
	259	info.si_errno = 0;
	260	info.si_code = BUS_ADRALN;
	261	info.si_addr = (void *) regs->excvaddr;
	262	force_sig_info(SIGSEGV, &info, current);
	263
	264	}
	265	#endif
	266	#endif
	267
	268	void
	269	do_debug(struct pt_regs *regs)
	270	{
	271	#ifdef CONFIG_KGDB
	272	/* If remote debugging is configured AND enabled, we give control to
	273	* kgdb. Otherwise, we fall through, perhaps giving control to the
	274	* native debugger.
	275	*/
	276
	277	if (gdb_enter) {
	278	extern void gdb_handle_exception(struct pt_regs *);
	279	gdb_handle_exception(regs);
	280	return_from_debug_flag = 1;
	281	return;
	282	}
	283	#endif
	284
	285	__die_if_kernel("Breakpoint in kernel", regs, SIGKILL);
	286
	287	/* If in user mode, send SIGTRAP signal to current process */
	288
	289	force_sig(SIGTRAP, current);
	290	}
	291
	292
	293	/*
	294	* Initialize dispatch tables.
	295	*
	296	* The exception vectors are stored compressed the __init section in the
	297	* dispatch_init_table. This function initializes the following three tables
	298	* from that compressed table:
	299	* - fast user first dispatch table for user exceptions
	300	* - fast kernel first dispatch table for kernel exceptions
	301	* - default C-handler C-handler called by the default fast handler.
	302	*
	303	* See vectors.S for more details.
	304	*/
	305
	306	#define set_handler(idx,handler) (exc_table[idx] = (unsigned long) (handler))
	307
b91dc336	308	void __init trap_init(void)
5a0015d6 CZ	309	{
	310	int i;
	311
	312	/* Setup default vectors. */
	313
	314	for(i = 0; i < 64; i++) {
	315	set_handler(EXC_TABLE_FAST_USER/4 + i, user_exception);
	316	set_handler(EXC_TABLE_FAST_KERNEL/4 + i, kernel_exception);
	317	set_handler(EXC_TABLE_DEFAULT/4 + i, do_unhandled);
	318	}
	319
	320	/* Setup specific handlers. */
	321
	322	for(i = 0; dispatch_init_table[i].cause >= 0; i++) {
	323
	324	int fast = dispatch_init_table[i].fast;
	325	int cause = dispatch_init_table[i].cause;
	326	void *handler = dispatch_init_table[i].handler;
	327
	328	if (fast == 0)
	329	set_handler (EXC_TABLE_DEFAULT/4 + cause, handler);
	330	if (fast && fast & USER)
	331	set_handler (EXC_TABLE_FAST_USER/4 + cause, handler);
	332	if (fast && fast & KRNL)
	333	set_handler (EXC_TABLE_FAST_KERNEL/4 + cause, handler);
	334	}
	335
	336	/* Initialize EXCSAVE_1 to hold the address of the exception table. */
	337
	338	i = (unsigned long)exc_table;
	339	__asm__ __volatile__("wsr %0, "__stringify(EXCSAVE_1)"\n" : : "a" (i));
	340	}
	341
	342	/*
	343	* This function dumps the current valid window frame and other base registers.
	344	*/
	345
	346	void show_regs(struct pt_regs * regs)
	347	{
	348	int i, wmask;
	349
	350	wmask = regs->wmask & ~1;
	351
8d7e8240	352	for (i = 0; i < 16; i++) {
5a0015d6 CZ	353	if ((i % 8) == 0)
	354	printk ("\n" KERN_INFO "a%02d: ", i);
	355	printk("%08lx ", regs->areg[i]);
	356	}
	357	printk("\n");
	358
	359	printk("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n",
	360	regs->pc, regs->ps, regs->depc, regs->excvaddr);
	361	printk("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n",
	362	regs->lbeg, regs->lend, regs->lcount, regs->sar);
	363	if (user_mode(regs))
	364	printk("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n",
	365	regs->windowbase, regs->windowstart, regs->wmask,
	366	regs->syscall);
	367	}
	368
	369	void show_trace(struct task_struct task, unsigned long sp)
	370	{
	371	unsigned long a0, a1, pc;
	372	unsigned long sp_start, sp_end;
	373
	374	a1 = (unsigned long)sp;
	375
	376	if (a1 == 0)
	377	__asm__ __volatile__ ("mov %0, a1\n" : "=a"(a1));
	378
	379
	380	sp_start = a1 & ~(THREAD_SIZE-1);
	381	sp_end = sp_start + THREAD_SIZE;
	382
	383	printk("Call Trace:");
	384	#ifdef CONFIG_KALLSYMS
	385	printk("\n");
	386	#endif
	387	spill_registers();
	388
	389	while (a1 > sp_start && a1 < sp_end) {
	390	sp = (unsigned long*)a1;
	391
	392	a0 = *(sp - 4);
	393	a1 = *(sp - 3);
	394
	395	if (a1 <= (unsigned long) sp)
	396	break;
	397
	398	pc = MAKE_PC_FROM_RA(a0, a1);
	399
	400	if (kernel_text_address(pc)) {
	401	printk(" [<%08lx>] ", pc);
	402	print_symbol("%s\n", pc);
	403	}
	404	}
	405	printk("\n");
	406	}
	407
	408	/*
	409	* This routine abuses get_user()/put_user() to reference pointers
	410	* with at least a bit of error checking ...
	411	*/
	412
	413	static int kstack_depth_to_print = 24;
	414
	415	void show_stack(struct task_struct task, unsigned long sp)
	416	{
417	int i = 0;
418	unsigned long *stack;
419
420	if (sp == 0)
421	__asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp));
422
423	stack = sp;
424
425	printk("\nStack: ");
426
427	for (i = 0; i < kstack_depth_to_print; i++) {
428	if (kstack_end(sp))
429	break;
430	if (i && ((i % 8) == 0))
431	printk("\n ");
432	printk("%08lx ", *sp++);
433	}
434	printk("\n");
435	show_trace(task, stack);
436	}
437
438	void dump_stack(void)
439	{
440	show_stack(current, NULL);
441	}
442
443	EXPORT_SYMBOL(dump_stack);
444
445
446	void show_code(unsigned int *pc)
447	{
448	long i;
449
450	printk("\nCode:");
451
452	for(i = -3 ; i < 6 ; i++) {
453	unsigned long insn;
454	if (__get_user(insn, pc + i)) {
455	printk(" (Bad address in pc)\n");
456	break;
457	}
458	printk("%c%08lx%c",(i?' ':'<'),insn,(i?' ':'>'));
459	}
460	}
461
34af946a	462	DEFINE_SPINLOCK(die_lock);
5a0015d6 CZ	463
	464	void die(const char * str, struct pt_regs * regs, long err)
	465	{
	466	static int die_counter;
	467	int nl = 0;
	468
	469	console_verbose();
	470	spin_lock_irq(&die_lock);
	471
	472	printk("%s: sig: %ld [#%d]\n", str, err, ++die_counter);
	473	#ifdef CONFIG_PREEMPT
	474	printk("PREEMPT ");
	475	nl = 1;
	476	#endif
	477	if (nl)
	478	printk("\n");
	479	show_regs(regs);
	480	if (!user_mode(regs))
	481	show_stack(NULL, (unsigned long*)regs->areg[1]);
	482
bcdcd8e7	483	add_taint(TAINT_DIE);
5a0015d6 CZ	484	spin_unlock_irq(&die_lock);
	485
	486	if (in_interrupt())
	487	panic("Fatal exception in interrupt");
	488
cea6a4ba	489	if (panic_on_oops)
012c437d	490	panic("Fatal exception");
cea6a4ba	491
5a0015d6 CZ	492	do_exit(err);
	493	}
	494
	495