[linux-block.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 <linux/hardirq.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
#ifdef CONFIG_MMU
{ 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 },
#endif /* CONFIG_MMU */
/* 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(KERN_INFO "a%02d:", i);
		printk(KERN_CONT " %08lx", regs->areg[i]);
	}
	printk(KERN_CONT "\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);
}

static __always_inline unsigned long *stack_pointer(struct task_struct *task)
{
	unsigned long *sp;

	if (!task || task == current)
		__asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp));
	else
		sp = (unsigned long *)task->thread.sp;

	return sp;
}

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

	if (sp)
		a1 = (unsigned long)sp;
	else
		a1 = (unsigned long)stack_pointer(task);

	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)
		sp = stack_pointer(task);
 	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>
5a891ed5	33	#include <linux/hardirq.h>
5a0015d6 CZ	34
	35	#include <asm/ptrace.h>
	36	#include <asm/timex.h>
	37	#include <asm/uaccess.h>
	38	#include <asm/pgtable.h>
	39	#include <asm/processor.h>
	40
	41	#ifdef CONFIG_KGDB
	42	extern int gdb_enter;
	43	extern int return_from_debug_flag;
	44	#endif
	45
	46	/*
	47	* Machine specific interrupt handlers
	48	*/
	49
	50	extern void kernel_exception(void);
	51	extern void user_exception(void);
	52
	53	extern void fast_syscall_kernel(void);
	54	extern void fast_syscall_user(void);
	55	extern void fast_alloca(void);
	56	extern void fast_unaligned(void);
	57	extern void fast_second_level_miss(void);
	58	extern void fast_store_prohibited(void);
	59	extern void fast_coprocessor(void);
	60
	61	extern void do_illegal_instruction (struct pt_regs*);
	62	extern void do_interrupt (struct pt_regs*);
	63	extern void do_unaligned_user (struct pt_regs*);
	64	extern void do_multihit (struct pt_regs*, unsigned long);
	65	extern void do_page_fault (struct pt_regs*, unsigned long);
	66	extern void do_debug (struct pt_regs*);
	67	extern void system_call (struct pt_regs*);
	68
	69	/*
	70	* The vector table must be preceded by a save area (which
	71	* implies it must be in RAM, unless one places RAM immediately
	72	* before a ROM and puts the vector at the start of the ROM (!))
	73	*/
	74
	75	#define KRNL 0x01
	76	#define USER 0x02
	77
	78	#define COPROCESSOR(x) \
173d6681	79	{ EXCCAUSE_COPROCESSOR ## x ## _DISABLED, USER, fast_coprocessor }
5a0015d6 CZ	80
	81	typedef struct {
	82	int cause;
	83	int fast;
	84	void* handler;
	85	} dispatch_init_table_t;
	86
b91dc336	87	static dispatch_init_table_t __initdata dispatch_init_table[] = {
5a0015d6	88
173d6681 CZ	89	{ EXCCAUSE_ILLEGAL_INSTRUCTION, 0, do_illegal_instruction},
	90	{ EXCCAUSE_SYSTEM_CALL, KRNL, fast_syscall_kernel },
	91	{ EXCCAUSE_SYSTEM_CALL, USER, fast_syscall_user },
	92	{ EXCCAUSE_SYSTEM_CALL, 0, system_call },
	93	/* EXCCAUSE_INSTRUCTION_FETCH unhandled */
	94	/* EXCCAUSE_LOAD_STORE_ERROR unhandled*/
	95	{ EXCCAUSE_LEVEL1_INTERRUPT, 0, do_interrupt },
	96	{ EXCCAUSE_ALLOCA, USER\|KRNL, fast_alloca },
	97	/* EXCCAUSE_INTEGER_DIVIDE_BY_ZERO unhandled */
	98	/* EXCCAUSE_PRIVILEGED unhandled */
5a0015d6 CZ	99	#if XCHAL_UNALIGNED_LOAD_EXCEPTION \|\| XCHAL_UNALIGNED_STORE_EXCEPTION
5a0015d6 CZ	100	#ifdef CONFIG_UNALIGNED_USER
173d6681	101	{ EXCCAUSE_UNALIGNED, USER, fast_unaligned },
5a0015d6	102	#else
173d6681	103	{ EXCCAUSE_UNALIGNED, 0, do_unaligned_user },
5a0015d6	104	#endif
173d6681	105	{ EXCCAUSE_UNALIGNED, KRNL, fast_unaligned },
5a0015d6	106	#endif
e5083a63	107	#ifdef CONFIG_MMU
173d6681 CZ	108	{ EXCCAUSE_ITLB_MISS, 0, do_page_fault },
	109	{ EXCCAUSE_ITLB_MISS, USER\|KRNL, fast_second_level_miss},
	110	{ EXCCAUSE_ITLB_MULTIHIT, 0, do_multihit },
	111	{ EXCCAUSE_ITLB_PRIVILEGE, 0, do_page_fault },
	112	/* EXCCAUSE_SIZE_RESTRICTION unhandled */
	113	{ EXCCAUSE_FETCH_CACHE_ATTRIBUTE, 0, do_page_fault },
	114	{ EXCCAUSE_DTLB_MISS, USER\|KRNL, fast_second_level_miss},
	115	{ EXCCAUSE_DTLB_MISS, 0, do_page_fault },
	116	{ EXCCAUSE_DTLB_MULTIHIT, 0, do_multihit },
	117	{ EXCCAUSE_DTLB_PRIVILEGE, 0, do_page_fault },
	118	/* EXCCAUSE_DTLB_SIZE_RESTRICTION unhandled */
	119	{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, USER\|KRNL, fast_store_prohibited },
	120	{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, 0, do_page_fault },
	121	{ EXCCAUSE_LOAD_CACHE_ATTRIBUTE, 0, do_page_fault },
e5083a63	122	#endif /* CONFIG_MMU */
5a0015d6	123	/* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */
c658eac6	124	#if XTENSA_HAVE_COPROCESSOR(0)
5a0015d6 CZ	125	COPROCESSOR(0),
5a0015d6 CZ	126	#endif
c658eac6	127	#if XTENSA_HAVE_COPROCESSOR(1)
5a0015d6 CZ	128	COPROCESSOR(1),
5a0015d6 CZ	129	#endif
c658eac6	130	#if XTENSA_HAVE_COPROCESSOR(2)
5a0015d6 CZ	131	COPROCESSOR(2),
5a0015d6 CZ	132	#endif
c658eac6	133	#if XTENSA_HAVE_COPROCESSOR(3)
5a0015d6 CZ	134	COPROCESSOR(3),
5a0015d6 CZ	135	#endif
c658eac6	136	#if XTENSA_HAVE_COPROCESSOR(4)
5a0015d6 CZ	137	COPROCESSOR(4),
5a0015d6 CZ	138	#endif
c658eac6	139	#if XTENSA_HAVE_COPROCESSOR(5)
5a0015d6 CZ	140	COPROCESSOR(5),
5a0015d6 CZ	141	#endif
c658eac6	142	#if XTENSA_HAVE_COPROCESSOR(6)
5a0015d6 CZ	143	COPROCESSOR(6),
5a0015d6 CZ	144	#endif
c658eac6	145	#if XTENSA_HAVE_COPROCESSOR(7)
5a0015d6 CZ	146	COPROCESSOR(7),
	147	#endif
	148	{ EXCCAUSE_MAPPED_DEBUG, 0, do_debug },
	149	{ -1, -1, 0 }
	150
	151	};
	152
	153	/* The exception table <exc_table> serves two functions:
	154	* 1. it contains three dispatch tables (fast_user, fast_kernel, default-c)
	155	* 2. it is a temporary memory buffer for the exception handlers.
	156	*/
	157
	158	unsigned long exc_table[EXC_TABLE_SIZE/4];
	159
	160	void die(const char, struct pt_regs, long);
	161
	162	static inline void
	163	__die_if_kernel(const char str, struct pt_regs regs, long err)
	164	{
	165	if (!user_mode(regs))
	166	die(str, regs, err);
	167	}
	168
	169	/*
	170	* Unhandled Exceptions. Kill user task or panic if in kernel space.
	171	*/
	172
	173	void do_unhandled(struct pt_regs *regs, unsigned long exccause)
	174	{
	175	__die_if_kernel("Caught unhandled exception - should not happen",
	176	regs, SIGKILL);
	177
	178	/* If in user mode, send SIGILL signal to current process */
	179	printk("Caught unhandled exception in '%s' "
	180	"(pid = %d, pc = %#010lx) - should not happen\n"
	181	"\tEXCCAUSE is %ld\n",
19c5870c	182	current->comm, task_pid_nr(current), regs->pc, exccause);
5a0015d6 CZ	183	force_sig(SIGILL, current);
	184	}
	185
	186	/*
	187	* Multi-hit exception. This if fatal!
	188	*/
	189
	190	void do_multihit(struct pt_regs *regs, unsigned long exccause)
	191	{
	192	die("Caught multihit exception", regs, SIGKILL);
	193	}
	194
	195	/*
	196	* Level-1 interrupt.
	197	* We currently have no priority encoding.
	198	*/
	199
	200	unsigned long ignored_level1_interrupts;
	201	extern void do_IRQ(int, struct pt_regs *);
	202
	203	void do_interrupt (struct pt_regs *regs)
	204	{
	205	unsigned long intread = get_sr (INTREAD);
	206	unsigned long intenable = get_sr (INTENABLE);
	207	int i, mask;
	208
	209	/* Handle all interrupts (no priorities).
	210	* (Clear the interrupt before processing, in case it's
	211	* edge-triggered or software-generated)
	212	*/
	213
	214	for (i=0, mask = 1; i < XCHAL_NUM_INTERRUPTS; i++, mask <<= 1) {
	215	if (mask & (intread & intenable)) {
	216	set_sr (mask, INTCLEAR);
	217	do_IRQ (i,regs);
	218	}
	219	}
	220	}
	221
	222	/*
	223	* Illegal instruction. Fatal if in kernel space.
	224	*/
	225
	226	void
	227	do_illegal_instruction(struct pt_regs *regs)
	228	{
	229	__die_if_kernel("Illegal instruction in kernel", regs, SIGKILL);
	230
	231	/* If in user mode, send SIGILL signal to current process. */
	232
	233	printk("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n",
19c5870c	234	current->comm, task_pid_nr(current), regs->pc);
5a0015d6 CZ	235	force_sig(SIGILL, current);
	236	}
	237
	238
	239	/*
	240	* Handle unaligned memory accesses from user space. Kill task.
	241	*
	242	* If CONFIG_UNALIGNED_USER is not set, we don't allow unaligned memory
	243	* accesses causes from user space.
	244	*/
	245
	246	#if XCHAL_UNALIGNED_LOAD_EXCEPTION \|\| XCHAL_UNALIGNED_STORE_EXCEPTION
	247	#ifndef CONFIG_UNALIGNED_USER
	248	void
	249	do_unaligned_user (struct pt_regs *regs)
	250	{
	251	siginfo_t info;
	252
	253	__die_if_kernel("Unhandled unaligned exception in kernel",
	254	regs, SIGKILL);
	255
	256	current->thread.bad_vaddr = regs->excvaddr;
	257	current->thread.error_code = -3;
	258	printk("Unaligned memory access to %08lx in '%s' "
	259	"(pid = %d, pc = %#010lx)\n",
19c5870c	260	regs->excvaddr, current->comm, task_pid_nr(current), regs->pc);
5a0015d6 CZ	261	info.si_signo = SIGBUS;
	262	info.si_errno = 0;
	263	info.si_code = BUS_ADRALN;
	264	info.si_addr = (void *) regs->excvaddr;
	265	force_sig_info(SIGSEGV, &info, current);
	266
	267	}
	268	#endif
	269	#endif
	270
	271	void
	272	do_debug(struct pt_regs *regs)
	273	{
	274	#ifdef CONFIG_KGDB
	275	/* If remote debugging is configured AND enabled, we give control to
	276	* kgdb. Otherwise, we fall through, perhaps giving control to the
	277	* native debugger.
	278	*/
	279
	280	if (gdb_enter) {
	281	extern void gdb_handle_exception(struct pt_regs *);
	282	gdb_handle_exception(regs);
	283	return_from_debug_flag = 1;
	284	return;
	285	}
	286	#endif
	287
	288	__die_if_kernel("Breakpoint in kernel", regs, SIGKILL);
	289
	290	/* If in user mode, send SIGTRAP signal to current process */
	291
	292	force_sig(SIGTRAP, current);
	293	}
	294
	295
	296	/*
	297	* Initialize dispatch tables.
	298	*
	299	* The exception vectors are stored compressed the __init section in the
	300	* dispatch_init_table. This function initializes the following three tables
	301	* from that compressed table:
	302	* - fast user first dispatch table for user exceptions
	303	* - fast kernel first dispatch table for kernel exceptions
	304	* - default C-handler C-handler called by the default fast handler.
	305	*
	306	* See vectors.S for more details.
	307	*/
	308
	309	#define set_handler(idx,handler) (exc_table[idx] = (unsigned long) (handler))
	310
b91dc336	311	void __init trap_init(void)
5a0015d6 CZ	312	{
	313	int i;
	314
	315	/* Setup default vectors. */
	316
	317	for(i = 0; i < 64; i++) {
	318	set_handler(EXC_TABLE_FAST_USER/4 + i, user_exception);
	319	set_handler(EXC_TABLE_FAST_KERNEL/4 + i, kernel_exception);
	320	set_handler(EXC_TABLE_DEFAULT/4 + i, do_unhandled);
	321	}
	322
	323	/* Setup specific handlers. */
	324
	325	for(i = 0; dispatch_init_table[i].cause >= 0; i++) {
	326
	327	int fast = dispatch_init_table[i].fast;
	328	int cause = dispatch_init_table[i].cause;
	329	void *handler = dispatch_init_table[i].handler;
	330
	331	if (fast == 0)
	332	set_handler (EXC_TABLE_DEFAULT/4 + cause, handler);
	333	if (fast && fast & USER)
	334	set_handler (EXC_TABLE_FAST_USER/4 + cause, handler);
	335	if (fast && fast & KRNL)
	336	set_handler (EXC_TABLE_FAST_KERNEL/4 + cause, handler);
	337	}
	338
	339	/* Initialize EXCSAVE_1 to hold the address of the exception table. */
	340
	341	i = (unsigned long)exc_table;
	342	__asm__ __volatile__("wsr %0, "__stringify(EXCSAVE_1)"\n" : : "a" (i));
	343	}
	344
	345	/*
	346	* This function dumps the current valid window frame and other base registers.
	347	*/
	348
	349	void show_regs(struct pt_regs * regs)
	350	{
	351	int i, wmask;
	352
	353	wmask = regs->wmask & ~1;
	354
8d7e8240	355	for (i = 0; i < 16; i++) {
5a0015d6	356	if ((i % 8) == 0)
ad361c98 JP	357	printk(KERN_INFO "a%02d:", i);
ad361c98 JP	358	printk(KERN_CONT " %08lx", regs->areg[i]);
5a0015d6	359	}
ad361c98	360	printk(KERN_CONT "\n");
5a0015d6 CZ	361
	362	printk("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n",
	363	regs->pc, regs->ps, regs->depc, regs->excvaddr);
	364	printk("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n",
	365	regs->lbeg, regs->lend, regs->lcount, regs->sar);
	366	if (user_mode(regs))
	367	printk("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n",
	368	regs->windowbase, regs->windowstart, regs->wmask,
	369	regs->syscall);
	370	}
	371
586411dc JW	372	static __always_inline unsigned long stack_pointer(struct task_struct task)
	373	{
	374	unsigned long *sp;
	375
	376	if (!task \|\| task == current)
	377	__asm__ __volatile__ ("mov %0, a1\n" : "=a"(sp));
	378	else
	379	sp = (unsigned long *)task->thread.sp;
	380
	381	return sp;
	382	}
	383
5a0015d6 CZ	384	void show_trace(struct task_struct task, unsigned long sp)
	385	{
	386	unsigned long a0, a1, pc;
	387	unsigned long sp_start, sp_end;
	388
28a0ce7f JW	389	if (sp)
	390	a1 = (unsigned long)sp;
	391	else
586411dc	392	a1 = (unsigned long)stack_pointer(task);
5a0015d6 CZ	393
	394	sp_start = a1 & ~(THREAD_SIZE-1);
	395	sp_end = sp_start + THREAD_SIZE;
	396
	397	printk("Call Trace:");
	398	#ifdef CONFIG_KALLSYMS
	399	printk("\n");
	400	#endif
	401	spill_registers();
	402
	403	while (a1 > sp_start && a1 < sp_end) {
	404	sp = (unsigned long*)a1;
	405
	406	a0 = *(sp - 4);
	407	a1 = *(sp - 3);
	408
	409	if (a1 <= (unsigned long) sp)
	410	break;
	411
	412	pc = MAKE_PC_FROM_RA(a0, a1);
	413
	414	if (kernel_text_address(pc)) {
	415	printk(" [<%08lx>] ", pc);
	416	print_symbol("%s\n", pc);
	417	}
	418	}
	419	printk("\n");
	420	}
	421
	422	/*
	423	* This routine abuses get_user()/put_user() to reference pointers
	424	* with at least a bit of error checking ...
	425	*/
	426
	427	static int kstack_depth_to_print = 24;
	428
	429	void show_stack(struct task_struct task, unsigned long sp)
	430	{
	431	int i = 0;
	432	unsigned long *stack;
	433
28a0ce7f	434	if (!sp)
586411dc	435	sp = stack_pointer(task);
5a0015d6 CZ	436	stack = sp;
	437
	438	printk("\nStack: ");
	439
	440	for (i = 0; i < kstack_depth_to_print; i++) {
	441	if (kstack_end(sp))
	442	break;
	443	if (i && ((i % 8) == 0))
	444	printk("\n ");
	445	printk("%08lx ", *sp++);
	446	}
	447	printk("\n");
	448	show_trace(task, stack);
	449	}
	450
	451	void dump_stack(void)
	452	{
	453	show_stack(current, NULL);
	454	}
	455
	456	EXPORT_SYMBOL(dump_stack);
	457
	458
	459	void show_code(unsigned int *pc)
	460	{
	461	long i;
	462
	463	printk("\nCode:");
	464
	465	for(i = -3 ; i < 6 ; i++) {
	466	unsigned long insn;
	467	if (__get_user(insn, pc + i)) {
	468	printk(" (Bad address in pc)\n");
	469	break;
	470	}
	471	printk("%c%08lx%c",(i?' ':'<'),insn,(i?' ':'>'));
	472	}
	473	}
	474
34af946a	475	DEFINE_SPINLOCK(die_lock);
5a0015d6 CZ	476
	477	void die(const char * str, struct pt_regs * regs, long err)
	478	{
	479	static int die_counter;
	480	int nl = 0;
	481
	482	console_verbose();
	483	spin_lock_irq(&die_lock);
	484
	485	printk("%s: sig: %ld [#%d]\n", str, err, ++die_counter);
	486	#ifdef CONFIG_PREEMPT
	487	printk("PREEMPT ");
	488	nl = 1;
	489	#endif
	490	if (nl)
	491	printk("\n");
	492	show_regs(regs);
	493	if (!user_mode(regs))
	494	show_stack(NULL, (unsigned long*)regs->areg[1]);
	495
bcdcd8e7	496	add_taint(TAINT_DIE);
5a0015d6 CZ	497	spin_unlock_irq(&die_lock);
	498
	499	if (in_interrupt())
	500	panic("Fatal exception in interrupt");
	501
cea6a4ba	502	if (panic_on_oops)
012c437d	503	panic("Fatal exception");
cea6a4ba	504
5a0015d6 CZ	505	do_exit(err);
	506	}
	507
	508