[mirror_ubuntu-artful-kernel.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/signal.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 <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/traps.h>
#include <asm/hw_breakpoint.h>

/*
 * 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_nmi(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
#if XTENSA_FAKE_NMI
{ EXCCAUSE_MAPPED_NMI,			0,		do_nmi },
#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]);

DEFINE_PER_CPU(struct debug_table, debug_table);

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 *);

#if XTENSA_FAKE_NMI

#define IS_POW2(v) (((v) & ((v) - 1)) == 0)

#if !(PROFILING_INTLEVEL == XCHAL_EXCM_LEVEL && \
      IS_POW2(XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL)))
#warning "Fake NMI is requested for PMM, but there are other IRQs at or above its level."
#warning "Fake NMI will be used, but there will be a bugcheck if one of those IRQs fire."

static inline void check_valid_nmi(void)
{
	unsigned intread = get_sr(interrupt);
	unsigned intenable = get_sr(intenable);

	BUG_ON(intread & intenable &
	       ~(XTENSA_INTLEVEL_ANDBELOW_MASK(PROFILING_INTLEVEL) ^
		 XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL) ^
		 BIT(XCHAL_PROFILING_INTERRUPT)));
}

#else

static inline void check_valid_nmi(void)
{
}

#endif

irqreturn_t xtensa_pmu_irq_handler(int irq, void *dev_id);

DEFINE_PER_CPU(unsigned long, nmi_count);

void do_nmi(struct pt_regs *regs)
{
	struct pt_regs *old_regs;

	if ((regs->ps & PS_INTLEVEL_MASK) < LOCKLEVEL)
		trace_hardirqs_off();

	old_regs = set_irq_regs(regs);
	nmi_enter();
	++*this_cpu_ptr(&nmi_count);
	check_valid_nmi();
	xtensa_pmu_irq_handler(0, NULL);
	nmi_exit();
	set_irq_regs(old_regs);
}
#endif

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;

	trace_hardirqs_off();

	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

/* Handle debug events.
 * When CONFIG_HAVE_HW_BREAKPOINT is on this handler is called with
 * preemption disabled to avoid rescheduling and keep mapping of hardware
 * breakpoint structures to debug registers intact, so that
 * DEBUGCAUSE.DBNUM could be used in case of data breakpoint hit.
 */
void
do_debug(struct pt_regs *regs)
{
#ifdef CONFIG_HAVE_HW_BREAKPOINT
	int ret = check_hw_breakpoint(regs);

	preempt_enable();
	if (ret == 0)
		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));
}

static void trap_init_debug(void)
{
	unsigned long debugsave = (unsigned long)this_cpu_ptr(&debug_table);

	this_cpu_ptr(&debug_table)->debug_exception = debug_exception;
	__asm__ __volatile__("wsr %0, excsave" __stringify(XCHAL_DEBUGLEVEL)
			     :: "a"(debugsave));
}

/*
 * 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();
	trap_init_debug();
}

#ifdef CONFIG_SMP
void secondary_trap_init(void)
{
	trap_init_excsave();
	trap_init_debug();
}
#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)
			pr_info("a%02d:", i);
		pr_cont(" %08lx", regs->areg[i]);
	}
	pr_cont("\n");
	pr_info("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n",
		regs->pc, regs->ps, regs->depc, regs->excvaddr);
	pr_info("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n",
		regs->lbeg, regs->lend, regs->lcount, regs->sar);
	if (user_mode(regs))
		pr_cont("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)) {
		pr_cont(" [<%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);

	pr_info("Call Trace:\n");
	walk_stackframe(sp, show_trace_cb, NULL);
#ifndef CONFIG_KALLSYMS
	pr_cont("\n");
#endif
}

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;

	pr_info("Stack:\n");

	for (i = 0; i < kstack_depth_to_print; i++) {
		if (kstack_end(sp))
			break;
		pr_cont(" %08lx", *sp++);
		if (i % 8 == 7)
			pr_cont("\n");
	}
	show_trace(task, stack);
}

DEFINE_SPINLOCK(die_lock);

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

	console_verbose();
	spin_lock_irq(&die_lock);

	pr_info("%s: sig: %ld [#%d]%s\n", str, err, ++die_counter,
		IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "");
	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>
3f07c014	27	#include <linux/sched/signal.h>
5a0015d6 CZ	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>
5a0015d6 CZ	37	#include <asm/timex.h>
7c0f6ba6	38	#include <linux/uaccess.h>
5a0015d6 CZ	39	#include <asm/pgtable.h>
5a0015d6 CZ	40	#include <asm/processor.h>
2d6f82fe	41	#include <asm/traps.h>
c91e02bd	42	#include <asm/hw_breakpoint.h>
5a0015d6	43
5a0015d6 CZ	44	/*
	45	* Machine specific interrupt handlers
	46	*/
	47
	48	extern void kernel_exception(void);
	49	extern void user_exception(void);
	50
	51	extern void fast_syscall_kernel(void);
	52	extern void fast_syscall_user(void);
	53	extern void fast_alloca(void);
	54	extern void fast_unaligned(void);
	55	extern void fast_second_level_miss(void);
	56	extern void fast_store_prohibited(void);
	57	extern void fast_coprocessor(void);
	58
	59	extern void do_illegal_instruction (struct pt_regs*);
	60	extern void do_interrupt (struct pt_regs*);
38fef73c	61	extern void do_nmi(struct pt_regs *);
5a0015d6 CZ	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	98	#if XCHAL_UNALIGNED_LOAD_EXCEPTION \|\| XCHAL_UNALIGNED_STORE_EXCEPTION
4ded6282	99	#ifdef CONFIG_XTENSA_UNALIGNED_USER
173d6681	100	{ EXCCAUSE_UNALIGNED, USER, fast_unaligned },
5a0015d6	101	#endif
3cfc096e	102	{ EXCCAUSE_UNALIGNED, 0, do_unaligned_user },
173d6681	103	{ EXCCAUSE_UNALIGNED, KRNL, fast_unaligned },
5a0015d6	104	#endif
e5083a63	105	#ifdef CONFIG_MMU
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 },
e5083a63	120	#endif /* CONFIG_MMU */
5a0015d6	121	/* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */
c658eac6	122	#if XTENSA_HAVE_COPROCESSOR(0)
5a0015d6 CZ	123	COPROCESSOR(0),
5a0015d6 CZ	124	#endif
c658eac6	125	#if XTENSA_HAVE_COPROCESSOR(1)
5a0015d6 CZ	126	COPROCESSOR(1),
5a0015d6 CZ	127	#endif
c658eac6	128	#if XTENSA_HAVE_COPROCESSOR(2)
5a0015d6 CZ	129	COPROCESSOR(2),
5a0015d6 CZ	130	#endif
c658eac6	131	#if XTENSA_HAVE_COPROCESSOR(3)
5a0015d6 CZ	132	COPROCESSOR(3),
5a0015d6 CZ	133	#endif
c658eac6	134	#if XTENSA_HAVE_COPROCESSOR(4)
5a0015d6 CZ	135	COPROCESSOR(4),
5a0015d6 CZ	136	#endif
c658eac6	137	#if XTENSA_HAVE_COPROCESSOR(5)
5a0015d6 CZ	138	COPROCESSOR(5),
5a0015d6 CZ	139	#endif
c658eac6	140	#if XTENSA_HAVE_COPROCESSOR(6)
5a0015d6 CZ	141	COPROCESSOR(6),
5a0015d6 CZ	142	#endif
c658eac6	143	#if XTENSA_HAVE_COPROCESSOR(7)
5a0015d6 CZ	144	COPROCESSOR(7),
5a0015d6 CZ	145	#endif
38fef73c MF	146	#if XTENSA_FAKE_NMI
	147	{ EXCCAUSE_MAPPED_NMI, 0, do_nmi },
	148	#endif
5a0015d6 CZ	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	160
6ec7026a MF	161	DEFINE_PER_CPU(struct debug_table, debug_table);
6ec7026a MF	162
5a0015d6 CZ	163	void die(const char, struct pt_regs, long);
	164
	165	static inline void
	166	__die_if_kernel(const char str, struct pt_regs regs, long err)
	167	{
	168	if (!user_mode(regs))
	169	die(str, regs, err);
	170	}
	171
	172	/*
	173	* Unhandled Exceptions. Kill user task or panic if in kernel space.
	174	*/
	175
	176	void do_unhandled(struct pt_regs *regs, unsigned long exccause)
	177	{
	178	__die_if_kernel("Caught unhandled exception - should not happen",
	179	regs, SIGKILL);
	180
	181	/* If in user mode, send SIGILL signal to current process */
	182	printk("Caught unhandled exception in '%s' "
	183	"(pid = %d, pc = %#010lx) - should not happen\n"
	184	"\tEXCCAUSE is %ld\n",
19c5870c	185	current->comm, task_pid_nr(current), regs->pc, exccause);
5a0015d6 CZ	186	force_sig(SIGILL, current);
	187	}
	188
	189	/*
	190	* Multi-hit exception. This if fatal!
	191	*/
	192
	193	void do_multihit(struct pt_regs *regs, unsigned long exccause)
	194	{
	195	die("Caught multihit exception", regs, SIGKILL);
	196	}
	197
	198	/*
2d1c645c	199	* IRQ handler.
5a0015d6 CZ	200	*/
5a0015d6 CZ	201
5a0015d6 CZ	202	extern void do_IRQ(int, struct pt_regs *);
5a0015d6 CZ	203
38fef73c MF	204	#if XTENSA_FAKE_NMI
38fef73c MF	205
e4629194 MF	206	#define IS_POW2(v) (((v) & ((v) - 1)) == 0)
	207
	208	#if !(PROFILING_INTLEVEL == XCHAL_EXCM_LEVEL && \
	209	IS_POW2(XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL)))
	210	#warning "Fake NMI is requested for PMM, but there are other IRQs at or above its level."
	211	#warning "Fake NMI will be used, but there will be a bugcheck if one of those IRQs fire."
	212
	213	static inline void check_valid_nmi(void)
	214	{
	215	unsigned intread = get_sr(interrupt);
	216	unsigned intenable = get_sr(intenable);
	217
	218	BUG_ON(intread & intenable &
	219	~(XTENSA_INTLEVEL_ANDBELOW_MASK(PROFILING_INTLEVEL) ^
	220	XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL) ^
	221	BIT(XCHAL_PROFILING_INTERRUPT)));
	222	}
	223
	224	#else
	225
	226	static inline void check_valid_nmi(void)
	227	{
	228	}
	229
	230	#endif
	231
38fef73c MF	232	irqreturn_t xtensa_pmu_irq_handler(int irq, void *dev_id);
	233
	234	DEFINE_PER_CPU(unsigned long, nmi_count);
	235
	236	void do_nmi(struct pt_regs *regs)
	237	{
	238	struct pt_regs *old_regs;
	239
	240	if ((regs->ps & PS_INTLEVEL_MASK) < LOCKLEVEL)
	241	trace_hardirqs_off();
	242
	243	old_regs = set_irq_regs(regs);
	244	nmi_enter();
	245	++*this_cpu_ptr(&nmi_count);
e4629194	246	check_valid_nmi();
38fef73c MF	247	xtensa_pmu_irq_handler(0, NULL);
	248	nmi_exit();
	249	set_irq_regs(old_regs);
	250	}
	251	#endif
	252
2d1c645c	253	void do_interrupt(struct pt_regs *regs)
5a0015d6	254	{
2d1c645c MG	255	static const unsigned int_level_mask[] = {
	256	0,
	257	XCHAL_INTLEVEL1_MASK,
	258	XCHAL_INTLEVEL2_MASK,
	259	XCHAL_INTLEVEL3_MASK,
	260	XCHAL_INTLEVEL4_MASK,
	261	XCHAL_INTLEVEL5_MASK,
	262	XCHAL_INTLEVEL6_MASK,
	263	XCHAL_INTLEVEL7_MASK,
	264	};
7d5f6a9a	265	struct pt_regs *old_regs;
99623239	266
7d5f6a9a MF	267	trace_hardirqs_off();
	268
	269	old_regs = set_irq_regs(regs);
99623239	270	irq_enter();
5a0015d6	271
2d1c645c MG	272	for (;;) {
	273	unsigned intread = get_sr(interrupt);
	274	unsigned intenable = get_sr(intenable);
895666a9 MF	275	unsigned int_at_level = intread & intenable;
	276	unsigned level;
	277
	278	for (level = LOCKLEVEL; level > 0; --level) {
	279	if (int_at_level & int_level_mask[level]) {
	280	int_at_level &= int_level_mask[level];
	281	break;
	282	}
	283	}
2d1c645c	284
895666a9	285	if (level == 0)
99623239 MF	286	break;
	287
	288	do_IRQ(__ffs(int_at_level), regs);
5a0015d6	289	}
99623239 MF	290
	291	irq_exit();
	292	set_irq_regs(old_regs);
5a0015d6 CZ	293	}
	294
	295	/*
	296	* Illegal instruction. Fatal if in kernel space.
	297	*/
	298
	299	void
	300	do_illegal_instruction(struct pt_regs *regs)
	301	{
	302	__die_if_kernel("Illegal instruction in kernel", regs, SIGKILL);
	303
	304	/* If in user mode, send SIGILL signal to current process. */
	305
	306	printk("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n",
19c5870c	307	current->comm, task_pid_nr(current), regs->pc);
5a0015d6 CZ	308	force_sig(SIGILL, current);
	309	}
	310
	311
	312	/*
	313	* Handle unaligned memory accesses from user space. Kill task.
	314	*
	315	* If CONFIG_UNALIGNED_USER is not set, we don't allow unaligned memory
	316	* accesses causes from user space.
	317	*/
	318
	319	#if XCHAL_UNALIGNED_LOAD_EXCEPTION \|\| XCHAL_UNALIGNED_STORE_EXCEPTION
5a0015d6 CZ	320	void
	321	do_unaligned_user (struct pt_regs *regs)
	322	{
	323	siginfo_t info;
	324
	325	__die_if_kernel("Unhandled unaligned exception in kernel",
	326	regs, SIGKILL);
	327
	328	current->thread.bad_vaddr = regs->excvaddr;
	329	current->thread.error_code = -3;
	330	printk("Unaligned memory access to %08lx in '%s' "
	331	"(pid = %d, pc = %#010lx)\n",
19c5870c	332	regs->excvaddr, current->comm, task_pid_nr(current), regs->pc);
5a0015d6 CZ	333	info.si_signo = SIGBUS;
	334	info.si_errno = 0;
	335	info.si_code = BUS_ADRALN;
	336	info.si_addr = (void *) regs->excvaddr;
	337	force_sig_info(SIGSEGV, &info, current);
	338
	339	}
	340	#endif
5a0015d6	341
c91e02bd MF	342	/* Handle debug events.
	343	* When CONFIG_HAVE_HW_BREAKPOINT is on this handler is called with
	344	* preemption disabled to avoid rescheduling and keep mapping of hardware
	345	* breakpoint structures to debug registers intact, so that
	346	* DEBUGCAUSE.DBNUM could be used in case of data breakpoint hit.
	347	*/
5a0015d6 CZ	348	void
	349	do_debug(struct pt_regs *regs)
	350	{
c91e02bd MF	351	#ifdef CONFIG_HAVE_HW_BREAKPOINT
	352	int ret = check_hw_breakpoint(regs);
	353
	354	preempt_enable();
	355	if (ret == 0)
	356	return;
	357	#endif
5a0015d6 CZ	358	__die_if_kernel("Breakpoint in kernel", regs, SIGKILL);
	359
	360	/* If in user mode, send SIGTRAP signal to current process */
	361
	362	force_sig(SIGTRAP, current);
	363	}
	364
	365
f615136c MF	366	static void set_handler(int idx, void *handler)
	367	{
	368	unsigned int cpu;
	369
	370	for_each_possible_cpu(cpu)
	371	per_cpu(exc_table, cpu)[idx] = (unsigned long)handler;
	372	}
	373
28570e8d MF	374	/* Set exception C handler - for temporary use when probing exceptions */
	375
	376	void * __init trap_set_handler(int cause, void *handler)
	377	{
f615136c MF	378	void previous = (void )per_cpu(exc_table, 0)[
	379	EXC_TABLE_DEFAULT / 4 + cause];
	380	set_handler(EXC_TABLE_DEFAULT / 4 + cause, handler);
28570e8d MF	381	return previous;
	382	}
	383
	384
49b424fe	385	static void trap_init_excsave(void)
f615136c MF	386	{
	387	unsigned long excsave1 = (unsigned long)this_cpu_ptr(exc_table);
	388	__asm__ __volatile__("wsr %0, excsave1\n" : : "a" (excsave1));
	389	}
	390
6ec7026a MF	391	static void trap_init_debug(void)
	392	{
	393	unsigned long debugsave = (unsigned long)this_cpu_ptr(&debug_table);
	394
	395	this_cpu_ptr(&debug_table)->debug_exception = debug_exception;
	396	__asm__ __volatile__("wsr %0, excsave" __stringify(XCHAL_DEBUGLEVEL)
	397	:: "a"(debugsave));
	398	}
	399
5a0015d6 CZ	400	/*
	401	* Initialize dispatch tables.
	402	*
	403	* The exception vectors are stored compressed the __init section in the
	404	* dispatch_init_table. This function initializes the following three tables
	405	* from that compressed table:
	406	* - fast user first dispatch table for user exceptions
	407	* - fast kernel first dispatch table for kernel exceptions
	408	* - default C-handler C-handler called by the default fast handler.
	409	*
	410	* See vectors.S for more details.
	411	*/
	412
b91dc336	413	void __init trap_init(void)
5a0015d6 CZ	414	{
	415	int i;
	416
	417	/* Setup default vectors. */
	418
	419	for(i = 0; i < 64; i++) {
	420	set_handler(EXC_TABLE_FAST_USER/4 + i, user_exception);
	421	set_handler(EXC_TABLE_FAST_KERNEL/4 + i, kernel_exception);
	422	set_handler(EXC_TABLE_DEFAULT/4 + i, do_unhandled);
	423	}
	424
	425	/* Setup specific handlers. */
	426
	427	for(i = 0; dispatch_init_table[i].cause >= 0; i++) {
	428
	429	int fast = dispatch_init_table[i].fast;
	430	int cause = dispatch_init_table[i].cause;
	431	void *handler = dispatch_init_table[i].handler;
	432
	433	if (fast == 0)
	434	set_handler (EXC_TABLE_DEFAULT/4 + cause, handler);
	435	if (fast && fast & USER)
	436	set_handler (EXC_TABLE_FAST_USER/4 + cause, handler);
	437	if (fast && fast & KRNL)
	438	set_handler (EXC_TABLE_FAST_KERNEL/4 + cause, handler);
	439	}
	440
	441	/* Initialize EXCSAVE_1 to hold the address of the exception table. */
f615136c	442	trap_init_excsave();
6ec7026a	443	trap_init_debug();
f615136c	444	}
5a0015d6	445
f615136c	446	#ifdef CONFIG_SMP
49b424fe	447	void secondary_trap_init(void)
f615136c MF	448	{
f615136c MF	449	trap_init_excsave();
6ec7026a	450	trap_init_debug();
5a0015d6	451	}
f615136c	452	#endif
5a0015d6 CZ	453
	454	/*
	455	* This function dumps the current valid window frame and other base registers.
	456	*/
	457
	458	void show_regs(struct pt_regs * regs)
	459	{
	460	int i, wmask;
	461
a43cb95d TH	462	show_regs_print_info(KERN_DEFAULT);
a43cb95d TH	463
5a0015d6 CZ	464	wmask = regs->wmask & ~1;
5a0015d6 CZ	465
8d7e8240	466	for (i = 0; i < 16; i++) {
5a0015d6	467	if ((i % 8) == 0)
d4eccafc MF	468	pr_info("a%02d:", i);
d4eccafc MF	469	pr_cont(" %08lx", regs->areg[i]);
5a0015d6	470	}
d4eccafc MF	471	pr_cont("\n");
	472	pr_info("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n",
	473	regs->pc, regs->ps, regs->depc, regs->excvaddr);
	474	pr_info("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n",
	475	regs->lbeg, regs->lend, regs->lcount, regs->sar);
5a0015d6	476	if (user_mode(regs))
d4eccafc MF	477	pr_cont("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n",
	478	regs->windowbase, regs->windowstart, regs->wmask,
	479	regs->syscall);
5a0015d6 CZ	480	}
5a0015d6 CZ	481
3e4196a5	482	static int show_trace_cb(struct stackframe frame, void data)
586411dc	483	{
3e4196a5	484	if (kernel_text_address(frame->pc)) {
d4eccafc MF	485	pr_cont(" [<%08lx>]", frame->pc);
d4eccafc MF	486	print_symbol(" %s\n", frame->pc);
3e4196a5 MF	487	}
3e4196a5 MF	488	return 0;
586411dc JW	489	}
586411dc JW	490
5a0015d6 CZ	491	void show_trace(struct task_struct task, unsigned long sp)
5a0015d6 CZ	492	{
3e4196a5 MF	493	if (!sp)
3e4196a5 MF	494	sp = stack_pointer(task);
5a0015d6	495
d4eccafc	496	pr_info("Call Trace:\n");
3e4196a5	497	walk_stackframe(sp, show_trace_cb, NULL);
d4eccafc MF	498	#ifndef CONFIG_KALLSYMS
	499	pr_cont("\n");
	500	#endif
5a0015d6 CZ	501	}
5a0015d6 CZ	502
5a0015d6 CZ	503	static int kstack_depth_to_print = 24;
	504
	505	void show_stack(struct task_struct task, unsigned long sp)
	506	{
	507	int i = 0;
	508	unsigned long *stack;
	509
28a0ce7f	510	if (!sp)
586411dc	511	sp = stack_pointer(task);
c4c4594b	512	stack = sp;
5a0015d6	513
d4eccafc	514	pr_info("Stack:\n");
5a0015d6 CZ	515
	516	for (i = 0; i < kstack_depth_to_print; i++) {
	517	if (kstack_end(sp))
	518	break;
d4eccafc MF	519	pr_cont(" %08lx", *sp++);
	520	if (i % 8 == 7)
	521	pr_cont("\n");
5a0015d6	522	}
5a0015d6 CZ	523	show_trace(task, stack);
	524	}
	525
34af946a	526	DEFINE_SPINLOCK(die_lock);
5a0015d6 CZ	527
	528	void die(const char * str, struct pt_regs * regs, long err)
	529	{
	530	static int die_counter;
5a0015d6 CZ	531
	532	console_verbose();
	533	spin_lock_irq(&die_lock);
	534
d4eccafc MF	535	pr_info("%s: sig: %ld [#%d]%s\n", str, err, ++die_counter,
d4eccafc MF	536	IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "");
5a0015d6 CZ	537	show_regs(regs);
	538	if (!user_mode(regs))
	539	show_stack(NULL, (unsigned long*)regs->areg[1]);
	540
373d4d09	541	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
5a0015d6 CZ	542	spin_unlock_irq(&die_lock);
	543
	544	if (in_interrupt())
	545	panic("Fatal exception in interrupt");
	546
cea6a4ba	547	if (panic_on_oops)
012c437d	548	panic("Fatal exception");
cea6a4ba	549
5a0015d6 CZ	550	do_exit(err);
5a0015d6 CZ	551	}