[linux-2.6-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 - 2013 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/stacktrace.h>
#include <asm/ptrace.h>
#include <asm/timex.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/traps.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_XTENSA_UNALIGNED_USER
{ EXCCAUSE_UNALIGNED,		USER,	   fast_unaligned },
#endif
{ EXCCAUSE_UNALIGNED,		0,	   do_unaligned_user },
{ 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.
 */

DEFINE_PER_CPU(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);
}

/*
 * IRQ handler.
 */

extern void do_IRQ(int, struct pt_regs *);

void do_interrupt(struct pt_regs *regs)
{
	static const unsigned int_level_mask[] = {
		0,
		XCHAL_INTLEVEL1_MASK,
		XCHAL_INTLEVEL2_MASK,
		XCHAL_INTLEVEL3_MASK,
		XCHAL_INTLEVEL4_MASK,
		XCHAL_INTLEVEL5_MASK,
		XCHAL_INTLEVEL6_MASK,
		XCHAL_INTLEVEL7_MASK,
	};
	struct pt_regs *old_regs = set_irq_regs(regs);

	irq_enter();

	for (;;) {
		unsigned intread = get_sr(interrupt);
		unsigned intenable = get_sr(intenable);
		unsigned int_at_level = intread & intenable;
		unsigned level;

		for (level = LOCKLEVEL; level > 0; --level) {
			if (int_at_level & int_level_mask[level]) {
				int_at_level &= int_level_mask[level];
				break;
			}
		}

		if (level == 0)
			break;

		do_IRQ(__ffs(int_at_level), regs);
	}

	irq_exit();
	set_irq_regs(old_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
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

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);
}


static void set_handler(int idx, void *handler)
{
	unsigned int cpu;

	for_each_possible_cpu(cpu)
		per_cpu(exc_table, cpu)[idx] = (unsigned long)handler;
}

/* Set exception C handler - for temporary use when probing exceptions */

void * __init trap_set_handler(int cause, void *handler)
{
	void *previous = (void *)per_cpu(exc_table, 0)[
		EXC_TABLE_DEFAULT / 4 + cause];
	set_handler(EXC_TABLE_DEFAULT / 4 + cause, handler);
	return previous;
}


static void trap_init_excsave(void)
{
	unsigned long excsave1 = (unsigned long)this_cpu_ptr(exc_table);
	__asm__ __volatile__("wsr  %0, excsave1\n" : : "a" (excsave1));
}

/*
 * 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.
 */

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. */
	trap_init_excsave();
}

#ifdef CONFIG_SMP
void secondary_trap_init(void)
{
	trap_init_excsave();
}
#endif

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

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

	show_regs_print_info(KERN_DEFAULT);

	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 int show_trace_cb(struct stackframe *frame, void *data)
{
	if (kernel_text_address(frame->pc)) {
		printk(" [<%08lx>] ", frame->pc);
		print_symbol("%s\n", frame->pc);
	}
	return 0;
}

void show_trace(struct task_struct *task, unsigned long *sp)
{
	if (!sp)
		sp = stack_pointer(task);

	printk("Call Trace:");
#ifdef CONFIG_KALLSYMS
	printk("\n");
#endif
	walk_stackframe(sp, show_trace_cb, NULL);
	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 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, LOCKDEP_NOW_UNRELIABLE);
	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	*
3e4196a5	14	* Copyright (C) 2001 - 2013 Tensilica Inc.
5a0015d6 CZ	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	34
3e4196a5	35	#include <asm/stacktrace.h>
5a0015d6 CZ	36	#include <asm/ptrace.h>
	37	#include <asm/timex.h>
	38	#include <asm/uaccess.h>
	39	#include <asm/pgtable.h>
	40	#include <asm/processor.h>
2d6f82fe	41	#include <asm/traps.h>
5a0015d6 CZ	42
	43	#ifdef CONFIG_KGDB
	44	extern int gdb_enter;
	45	extern int return_from_debug_flag;
	46	#endif
	47
	48	/*
	49	* Machine specific interrupt handlers
	50	*/
	51
	52	extern void kernel_exception(void);
	53	extern void user_exception(void);
	54
	55	extern void fast_syscall_kernel(void);
	56	extern void fast_syscall_user(void);
	57	extern void fast_alloca(void);
	58	extern void fast_unaligned(void);
	59	extern void fast_second_level_miss(void);
	60	extern void fast_store_prohibited(void);
	61	extern void fast_coprocessor(void);
	62
	63	extern void do_illegal_instruction (struct pt_regs*);
	64	extern void do_interrupt (struct pt_regs*);
	65	extern void do_unaligned_user (struct pt_regs*);
	66	extern void do_multihit (struct pt_regs*, unsigned long);
	67	extern void do_page_fault (struct pt_regs*, unsigned long);
	68	extern void do_debug (struct pt_regs*);
	69	extern void system_call (struct pt_regs*);
	70
	71	/*
	72	* The vector table must be preceded by a save area (which
	73	* implies it must be in RAM, unless one places RAM immediately
	74	* before a ROM and puts the vector at the start of the ROM (!))
	75	*/
	76
	77	#define KRNL 0x01
	78	#define USER 0x02
	79
	80	#define COPROCESSOR(x) \
173d6681	81	{ EXCCAUSE_COPROCESSOR ## x ## _DISABLED, USER, fast_coprocessor }
5a0015d6 CZ	82
	83	typedef struct {
	84	int cause;
	85	int fast;
	86	void* handler;
	87	} dispatch_init_table_t;
	88
b91dc336	89	static dispatch_init_table_t __initdata dispatch_init_table[] = {
5a0015d6	90
173d6681 CZ	91	{ EXCCAUSE_ILLEGAL_INSTRUCTION, 0, do_illegal_instruction},
	92	{ EXCCAUSE_SYSTEM_CALL, KRNL, fast_syscall_kernel },
	93	{ EXCCAUSE_SYSTEM_CALL, USER, fast_syscall_user },
	94	{ EXCCAUSE_SYSTEM_CALL, 0, system_call },
	95	/* EXCCAUSE_INSTRUCTION_FETCH unhandled */
	96	/* EXCCAUSE_LOAD_STORE_ERROR unhandled*/
	97	{ EXCCAUSE_LEVEL1_INTERRUPT, 0, do_interrupt },
	98	{ EXCCAUSE_ALLOCA, USER\|KRNL, fast_alloca },
	99	/* EXCCAUSE_INTEGER_DIVIDE_BY_ZERO unhandled */
	100	/* EXCCAUSE_PRIVILEGED unhandled */
5a0015d6	101	#if XCHAL_UNALIGNED_LOAD_EXCEPTION \|\| XCHAL_UNALIGNED_STORE_EXCEPTION
4ded6282	102	#ifdef CONFIG_XTENSA_UNALIGNED_USER
173d6681	103	{ EXCCAUSE_UNALIGNED, USER, fast_unaligned },
5a0015d6	104	#endif
3cfc096e	105	{ EXCCAUSE_UNALIGNED, 0, do_unaligned_user },
173d6681	106	{ EXCCAUSE_UNALIGNED, KRNL, fast_unaligned },
5a0015d6	107	#endif
e5083a63	108	#ifdef CONFIG_MMU
173d6681 CZ	109	{ EXCCAUSE_ITLB_MISS, 0, do_page_fault },
	110	{ EXCCAUSE_ITLB_MISS, USER\|KRNL, fast_second_level_miss},
	111	{ EXCCAUSE_ITLB_MULTIHIT, 0, do_multihit },
	112	{ EXCCAUSE_ITLB_PRIVILEGE, 0, do_page_fault },
	113	/* EXCCAUSE_SIZE_RESTRICTION unhandled */
	114	{ EXCCAUSE_FETCH_CACHE_ATTRIBUTE, 0, do_page_fault },
	115	{ EXCCAUSE_DTLB_MISS, USER\|KRNL, fast_second_level_miss},
	116	{ EXCCAUSE_DTLB_MISS, 0, do_page_fault },
	117	{ EXCCAUSE_DTLB_MULTIHIT, 0, do_multihit },
	118	{ EXCCAUSE_DTLB_PRIVILEGE, 0, do_page_fault },
	119	/* EXCCAUSE_DTLB_SIZE_RESTRICTION unhandled */
	120	{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, USER\|KRNL, fast_store_prohibited },
	121	{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, 0, do_page_fault },
	122	{ EXCCAUSE_LOAD_CACHE_ATTRIBUTE, 0, do_page_fault },
e5083a63	123	#endif /* CONFIG_MMU */
5a0015d6	124	/* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */
c658eac6	125	#if XTENSA_HAVE_COPROCESSOR(0)
5a0015d6 CZ	126	COPROCESSOR(0),
5a0015d6 CZ	127	#endif
c658eac6	128	#if XTENSA_HAVE_COPROCESSOR(1)
5a0015d6 CZ	129	COPROCESSOR(1),
5a0015d6 CZ	130	#endif
c658eac6	131	#if XTENSA_HAVE_COPROCESSOR(2)
5a0015d6 CZ	132	COPROCESSOR(2),
5a0015d6 CZ	133	#endif
c658eac6	134	#if XTENSA_HAVE_COPROCESSOR(3)
5a0015d6 CZ	135	COPROCESSOR(3),
5a0015d6 CZ	136	#endif
c658eac6	137	#if XTENSA_HAVE_COPROCESSOR(4)
5a0015d6 CZ	138	COPROCESSOR(4),
5a0015d6 CZ	139	#endif
c658eac6	140	#if XTENSA_HAVE_COPROCESSOR(5)
5a0015d6 CZ	141	COPROCESSOR(5),
5a0015d6 CZ	142	#endif
c658eac6	143	#if XTENSA_HAVE_COPROCESSOR(6)
5a0015d6 CZ	144	COPROCESSOR(6),
5a0015d6 CZ	145	#endif
c658eac6	146	#if XTENSA_HAVE_COPROCESSOR(7)
5a0015d6 CZ	147	COPROCESSOR(7),
	148	#endif
	149	{ EXCCAUSE_MAPPED_DEBUG, 0, do_debug },
	150	{ -1, -1, 0 }
	151
	152	};
	153
	154	/* The exception table <exc_table> serves two functions:
	155	* 1. it contains three dispatch tables (fast_user, fast_kernel, default-c)
	156	* 2. it is a temporary memory buffer for the exception handlers.
	157	*/
	158
f615136c	159	DEFINE_PER_CPU(unsigned long, exc_table[EXC_TABLE_SIZE/4]);
5a0015d6 CZ	160
	161	void die(const char, struct pt_regs, long);
	162
	163	static inline void
	164	__die_if_kernel(const char str, struct pt_regs regs, long err)
	165	{
	166	if (!user_mode(regs))
	167	die(str, regs, err);
	168	}
	169
	170	/*
	171	* Unhandled Exceptions. Kill user task or panic if in kernel space.
	172	*/
	173
	174	void do_unhandled(struct pt_regs *regs, unsigned long exccause)
	175	{
	176	__die_if_kernel("Caught unhandled exception - should not happen",
	177	regs, SIGKILL);
	178
	179	/* If in user mode, send SIGILL signal to current process */
	180	printk("Caught unhandled exception in '%s' "
	181	"(pid = %d, pc = %#010lx) - should not happen\n"
	182	"\tEXCCAUSE is %ld\n",
19c5870c	183	current->comm, task_pid_nr(current), regs->pc, exccause);
5a0015d6 CZ	184	force_sig(SIGILL, current);
	185	}
	186
	187	/*
	188	* Multi-hit exception. This if fatal!
	189	*/
	190
	191	void do_multihit(struct pt_regs *regs, unsigned long exccause)
	192	{
	193	die("Caught multihit exception", regs, SIGKILL);
	194	}
	195
	196	/*
2d1c645c	197	* IRQ handler.
5a0015d6 CZ	198	*/
5a0015d6 CZ	199
5a0015d6 CZ	200	extern void do_IRQ(int, struct pt_regs *);
5a0015d6 CZ	201
2d1c645c	202	void do_interrupt(struct pt_regs *regs)
5a0015d6	203	{
2d1c645c MG	204	static const unsigned int_level_mask[] = {
	205	0,
	206	XCHAL_INTLEVEL1_MASK,
	207	XCHAL_INTLEVEL2_MASK,
	208	XCHAL_INTLEVEL3_MASK,
	209	XCHAL_INTLEVEL4_MASK,
	210	XCHAL_INTLEVEL5_MASK,
	211	XCHAL_INTLEVEL6_MASK,
	212	XCHAL_INTLEVEL7_MASK,
	213	};
99623239 MF	214	struct pt_regs *old_regs = set_irq_regs(regs);
	215
	216	irq_enter();
5a0015d6	217
2d1c645c MG	218	for (;;) {
	219	unsigned intread = get_sr(interrupt);
	220	unsigned intenable = get_sr(intenable);
895666a9 MF	221	unsigned int_at_level = intread & intenable;
	222	unsigned level;
	223
	224	for (level = LOCKLEVEL; level > 0; --level) {
	225	if (int_at_level & int_level_mask[level]) {
	226	int_at_level &= int_level_mask[level];
	227	break;
	228	}
	229	}
2d1c645c	230
895666a9	231	if (level == 0)
99623239 MF	232	break;
	233
	234	do_IRQ(__ffs(int_at_level), regs);
5a0015d6	235	}
99623239 MF	236
	237	irq_exit();
	238	set_irq_regs(old_regs);
5a0015d6 CZ	239	}
	240
	241	/*
	242	* Illegal instruction. Fatal if in kernel space.
	243	*/
	244
	245	void
	246	do_illegal_instruction(struct pt_regs *regs)
	247	{
	248	__die_if_kernel("Illegal instruction in kernel", regs, SIGKILL);
	249
	250	/* If in user mode, send SIGILL signal to current process. */
	251
	252	printk("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n",
19c5870c	253	current->comm, task_pid_nr(current), regs->pc);
5a0015d6 CZ	254	force_sig(SIGILL, current);
	255	}
	256
	257
	258	/*
	259	* Handle unaligned memory accesses from user space. Kill task.
	260	*
	261	* If CONFIG_UNALIGNED_USER is not set, we don't allow unaligned memory
	262	* accesses causes from user space.
	263	*/
	264
	265	#if XCHAL_UNALIGNED_LOAD_EXCEPTION \|\| XCHAL_UNALIGNED_STORE_EXCEPTION
5a0015d6 CZ	266	void
	267	do_unaligned_user (struct pt_regs *regs)
	268	{
	269	siginfo_t info;
	270
	271	__die_if_kernel("Unhandled unaligned exception in kernel",
	272	regs, SIGKILL);
	273
	274	current->thread.bad_vaddr = regs->excvaddr;
	275	current->thread.error_code = -3;
	276	printk("Unaligned memory access to %08lx in '%s' "
	277	"(pid = %d, pc = %#010lx)\n",
19c5870c	278	regs->excvaddr, current->comm, task_pid_nr(current), regs->pc);
5a0015d6 CZ	279	info.si_signo = SIGBUS;
	280	info.si_errno = 0;
	281	info.si_code = BUS_ADRALN;
	282	info.si_addr = (void *) regs->excvaddr;
	283	force_sig_info(SIGSEGV, &info, current);
	284
	285	}
	286	#endif
5a0015d6 CZ	287
	288	void
	289	do_debug(struct pt_regs *regs)
	290	{
	291	#ifdef CONFIG_KGDB
	292	/* If remote debugging is configured AND enabled, we give control to
	293	* kgdb. Otherwise, we fall through, perhaps giving control to the
	294	* native debugger.
	295	*/
	296
	297	if (gdb_enter) {
	298	extern void gdb_handle_exception(struct pt_regs *);
	299	gdb_handle_exception(regs);
	300	return_from_debug_flag = 1;
	301	return;
	302	}
	303	#endif
	304
	305	__die_if_kernel("Breakpoint in kernel", regs, SIGKILL);
	306
	307	/* If in user mode, send SIGTRAP signal to current process */
	308
	309	force_sig(SIGTRAP, current);
	310	}
	311
	312
f615136c MF	313	static void set_handler(int idx, void *handler)
	314	{
	315	unsigned int cpu;
	316
	317	for_each_possible_cpu(cpu)
	318	per_cpu(exc_table, cpu)[idx] = (unsigned long)handler;
	319	}
	320
28570e8d MF	321	/* Set exception C handler - for temporary use when probing exceptions */
	322
	323	void * __init trap_set_handler(int cause, void *handler)
	324	{
f615136c MF	325	void previous = (void )per_cpu(exc_table, 0)[
	326	EXC_TABLE_DEFAULT / 4 + cause];
	327	set_handler(EXC_TABLE_DEFAULT / 4 + cause, handler);
28570e8d MF	328	return previous;
	329	}
	330
	331
49b424fe	332	static void trap_init_excsave(void)
f615136c MF	333	{
	334	unsigned long excsave1 = (unsigned long)this_cpu_ptr(exc_table);
	335	__asm__ __volatile__("wsr %0, excsave1\n" : : "a" (excsave1));
	336	}
	337
5a0015d6 CZ	338	/*
	339	* Initialize dispatch tables.
	340	*
	341	* The exception vectors are stored compressed the __init section in the
	342	* dispatch_init_table. This function initializes the following three tables
	343	* from that compressed table:
	344	* - fast user first dispatch table for user exceptions
	345	* - fast kernel first dispatch table for kernel exceptions
	346	* - default C-handler C-handler called by the default fast handler.
	347	*
	348	* See vectors.S for more details.
	349	*/
	350
b91dc336	351	void __init trap_init(void)
5a0015d6 CZ	352	{
	353	int i;
	354
	355	/* Setup default vectors. */
	356
	357	for(i = 0; i < 64; i++) {
	358	set_handler(EXC_TABLE_FAST_USER/4 + i, user_exception);
	359	set_handler(EXC_TABLE_FAST_KERNEL/4 + i, kernel_exception);
	360	set_handler(EXC_TABLE_DEFAULT/4 + i, do_unhandled);
	361	}
	362
	363	/* Setup specific handlers. */
	364
	365	for(i = 0; dispatch_init_table[i].cause >= 0; i++) {
	366
	367	int fast = dispatch_init_table[i].fast;
	368	int cause = dispatch_init_table[i].cause;
	369	void *handler = dispatch_init_table[i].handler;
	370
	371	if (fast == 0)
	372	set_handler (EXC_TABLE_DEFAULT/4 + cause, handler);
	373	if (fast && fast & USER)
	374	set_handler (EXC_TABLE_FAST_USER/4 + cause, handler);
	375	if (fast && fast & KRNL)
	376	set_handler (EXC_TABLE_FAST_KERNEL/4 + cause, handler);
	377	}
	378
	379	/* Initialize EXCSAVE_1 to hold the address of the exception table. */
f615136c MF	380	trap_init_excsave();
f615136c MF	381	}
5a0015d6	382
f615136c	383	#ifdef CONFIG_SMP
49b424fe	384	void secondary_trap_init(void)
f615136c MF	385	{
f615136c MF	386	trap_init_excsave();
5a0015d6	387	}
f615136c	388	#endif
5a0015d6 CZ	389
	390	/*
	391	* This function dumps the current valid window frame and other base registers.
	392	*/
	393
	394	void show_regs(struct pt_regs * regs)
	395	{
	396	int i, wmask;
	397
a43cb95d TH	398	show_regs_print_info(KERN_DEFAULT);
a43cb95d TH	399
5a0015d6 CZ	400	wmask = regs->wmask & ~1;
5a0015d6 CZ	401
8d7e8240	402	for (i = 0; i < 16; i++) {
5a0015d6	403	if ((i % 8) == 0)
ad361c98 JP	404	printk(KERN_INFO "a%02d:", i);
ad361c98 JP	405	printk(KERN_CONT " %08lx", regs->areg[i]);
5a0015d6	406	}
ad361c98	407	printk(KERN_CONT "\n");
5a0015d6 CZ	408
	409	printk("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n",
	410	regs->pc, regs->ps, regs->depc, regs->excvaddr);
	411	printk("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n",
	412	regs->lbeg, regs->lend, regs->lcount, regs->sar);
	413	if (user_mode(regs))
	414	printk("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n",
	415	regs->windowbase, regs->windowstart, regs->wmask,
	416	regs->syscall);
	417	}
	418
3e4196a5	419	static int show_trace_cb(struct stackframe frame, void data)
586411dc	420	{
3e4196a5 MF	421	if (kernel_text_address(frame->pc)) {
	422	printk(" [<%08lx>] ", frame->pc);
	423	print_symbol("%s\n", frame->pc);
	424	}
	425	return 0;
586411dc JW	426	}
586411dc JW	427
5a0015d6 CZ	428	void show_trace(struct task_struct task, unsigned long sp)
5a0015d6 CZ	429	{
3e4196a5 MF	430	if (!sp)
3e4196a5 MF	431	sp = stack_pointer(task);
5a0015d6 CZ	432
	433	printk("Call Trace:");
	434	#ifdef CONFIG_KALLSYMS
	435	printk("\n");
	436	#endif
3e4196a5	437	walk_stackframe(sp, show_trace_cb, NULL);
5a0015d6 CZ	438	printk("\n");
	439	}
	440
	441	/*
	442	* This routine abuses get_user()/put_user() to reference pointers
	443	* with at least a bit of error checking ...
	444	*/
	445
	446	static int kstack_depth_to_print = 24;
	447
	448	void show_stack(struct task_struct task, unsigned long sp)
	449	{
	450	int i = 0;
	451	unsigned long *stack;
	452
28a0ce7f	453	if (!sp)
586411dc	454	sp = stack_pointer(task);
c4c4594b	455	stack = sp;
5a0015d6 CZ	456
	457	printk("\nStack: ");
	458
	459	for (i = 0; i < kstack_depth_to_print; i++) {
	460	if (kstack_end(sp))
	461	break;
	462	if (i && ((i % 8) == 0))
	463	printk("\n ");
	464	printk("%08lx ", *sp++);
	465	}
	466	printk("\n");
	467	show_trace(task, stack);
	468	}
	469
5a0015d6 CZ	470	void show_code(unsigned int *pc)
	471	{
	472	long i;
	473
	474	printk("\nCode:");
	475
	476	for(i = -3 ; i < 6 ; i++) {
	477	unsigned long insn;
	478	if (__get_user(insn, pc + i)) {
	479	printk(" (Bad address in pc)\n");
	480	break;
	481	}
	482	printk("%c%08lx%c",(i?' ':'<'),insn,(i?' ':'>'));
	483	}
	484	}
	485
34af946a	486	DEFINE_SPINLOCK(die_lock);
5a0015d6 CZ	487
	488	void die(const char * str, struct pt_regs * regs, long err)
	489	{
	490	static int die_counter;
	491	int nl = 0;
	492
	493	console_verbose();
	494	spin_lock_irq(&die_lock);
	495
	496	printk("%s: sig: %ld [#%d]\n", str, err, ++die_counter);
	497	#ifdef CONFIG_PREEMPT
	498	printk("PREEMPT ");
	499	nl = 1;
	500	#endif
	501	if (nl)
	502	printk("\n");
	503	show_regs(regs);
	504	if (!user_mode(regs))
	505	show_stack(NULL, (unsigned long*)regs->areg[1]);
	506
373d4d09	507	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
5a0015d6 CZ	508	spin_unlock_irq(&die_lock);
	509
	510	if (in_interrupt())
	511	panic("Fatal exception in interrupt");
	512
cea6a4ba	513	if (panic_on_oops)
012c437d	514	panic("Fatal exception");
cea6a4ba	515
5a0015d6 CZ	516	do_exit(err);
5a0015d6 CZ	517	}