[mirror_ubuntu-bionic-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/sched/debug.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>
b17b0153	28	#include <linux/sched/debug.h>
5a0015d6 CZ	29	#include <linux/init.h>
	30	#include <linux/module.h>
	31	#include <linux/stringify.h>
	32	#include <linux/kallsyms.h>
5c888d53	33	#include <linux/delay.h>
5a891ed5	34	#include <linux/hardirq.h>
5a0015d6	35
3e4196a5	36	#include <asm/stacktrace.h>
5a0015d6 CZ	37	#include <asm/ptrace.h>
5a0015d6 CZ	38	#include <asm/timex.h>
7c0f6ba6	39	#include <linux/uaccess.h>
5a0015d6 CZ	40	#include <asm/pgtable.h>
5a0015d6 CZ	41	#include <asm/processor.h>
2d6f82fe	42	#include <asm/traps.h>
c91e02bd	43	#include <asm/hw_breakpoint.h>
5a0015d6	44
5a0015d6 CZ	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*);
38fef73c	62	extern void do_nmi(struct pt_regs *);
5a0015d6 CZ	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	99	#if XCHAL_UNALIGNED_LOAD_EXCEPTION \|\| XCHAL_UNALIGNED_STORE_EXCEPTION
4ded6282	100	#ifdef CONFIG_XTENSA_UNALIGNED_USER
173d6681	101	{ EXCCAUSE_UNALIGNED, USER, fast_unaligned },
5a0015d6	102	#endif
3cfc096e	103	{ EXCCAUSE_UNALIGNED, 0, do_unaligned_user },
173d6681	104	{ EXCCAUSE_UNALIGNED, KRNL, fast_unaligned },
5a0015d6	105	#endif
e5083a63	106	#ifdef CONFIG_MMU
173d6681 CZ	107	{ EXCCAUSE_ITLB_MISS, 0, do_page_fault },
	108	{ EXCCAUSE_ITLB_MISS, USER\|KRNL, fast_second_level_miss},
	109	{ EXCCAUSE_ITLB_MULTIHIT, 0, do_multihit },
	110	{ EXCCAUSE_ITLB_PRIVILEGE, 0, do_page_fault },
	111	/* EXCCAUSE_SIZE_RESTRICTION unhandled */
	112	{ EXCCAUSE_FETCH_CACHE_ATTRIBUTE, 0, do_page_fault },
	113	{ EXCCAUSE_DTLB_MISS, USER\|KRNL, fast_second_level_miss},
	114	{ EXCCAUSE_DTLB_MISS, 0, do_page_fault },
	115	{ EXCCAUSE_DTLB_MULTIHIT, 0, do_multihit },
	116	{ EXCCAUSE_DTLB_PRIVILEGE, 0, do_page_fault },
	117	/* EXCCAUSE_DTLB_SIZE_RESTRICTION unhandled */
	118	{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, USER\|KRNL, fast_store_prohibited },
	119	{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, 0, do_page_fault },
	120	{ EXCCAUSE_LOAD_CACHE_ATTRIBUTE, 0, do_page_fault },
e5083a63	121	#endif /* CONFIG_MMU */
5a0015d6	122	/* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */
c658eac6	123	#if XTENSA_HAVE_COPROCESSOR(0)
5a0015d6 CZ	124	COPROCESSOR(0),
5a0015d6 CZ	125	#endif
c658eac6	126	#if XTENSA_HAVE_COPROCESSOR(1)
5a0015d6 CZ	127	COPROCESSOR(1),
5a0015d6 CZ	128	#endif
c658eac6	129	#if XTENSA_HAVE_COPROCESSOR(2)
5a0015d6 CZ	130	COPROCESSOR(2),
5a0015d6 CZ	131	#endif
c658eac6	132	#if XTENSA_HAVE_COPROCESSOR(3)
5a0015d6 CZ	133	COPROCESSOR(3),
5a0015d6 CZ	134	#endif
c658eac6	135	#if XTENSA_HAVE_COPROCESSOR(4)
5a0015d6 CZ	136	COPROCESSOR(4),
5a0015d6 CZ	137	#endif
c658eac6	138	#if XTENSA_HAVE_COPROCESSOR(5)
5a0015d6 CZ	139	COPROCESSOR(5),
5a0015d6 CZ	140	#endif
c658eac6	141	#if XTENSA_HAVE_COPROCESSOR(6)
5a0015d6 CZ	142	COPROCESSOR(6),
5a0015d6 CZ	143	#endif
c658eac6	144	#if XTENSA_HAVE_COPROCESSOR(7)
5a0015d6 CZ	145	COPROCESSOR(7),
5a0015d6 CZ	146	#endif
38fef73c MF	147	#if XTENSA_FAKE_NMI
	148	{ EXCCAUSE_MAPPED_NMI, 0, do_nmi },
	149	#endif
5a0015d6 CZ	150	{ EXCCAUSE_MAPPED_DEBUG, 0, do_debug },
	151	{ -1, -1, 0 }
	152
	153	};
	154
	155	/* The exception table <exc_table> serves two functions:
	156	* 1. it contains three dispatch tables (fast_user, fast_kernel, default-c)
	157	* 2. it is a temporary memory buffer for the exception handlers.
	158	*/
	159
f615136c	160	DEFINE_PER_CPU(unsigned long, exc_table[EXC_TABLE_SIZE/4]);
5a0015d6	161
6ec7026a MF	162	DEFINE_PER_CPU(struct debug_table, debug_table);
6ec7026a MF	163
5a0015d6 CZ	164	void die(const char, struct pt_regs, long);
	165
	166	static inline void
	167	__die_if_kernel(const char str, struct pt_regs regs, long err)
	168	{
	169	if (!user_mode(regs))
	170	die(str, regs, err);
	171	}
	172
	173	/*
	174	* Unhandled Exceptions. Kill user task or panic if in kernel space.
	175	*/
	176
	177	void do_unhandled(struct pt_regs *regs, unsigned long exccause)
	178	{
	179	__die_if_kernel("Caught unhandled exception - should not happen",
	180	regs, SIGKILL);
	181
	182	/* If in user mode, send SIGILL signal to current process */
	183	printk("Caught unhandled exception in '%s' "
	184	"(pid = %d, pc = %#010lx) - should not happen\n"
	185	"\tEXCCAUSE is %ld\n",
19c5870c	186	current->comm, task_pid_nr(current), regs->pc, exccause);
5a0015d6 CZ	187	force_sig(SIGILL, current);
	188	}
	189
	190	/*
	191	* Multi-hit exception. This if fatal!
	192	*/
	193
	194	void do_multihit(struct pt_regs *regs, unsigned long exccause)
	195	{
	196	die("Caught multihit exception", regs, SIGKILL);
	197	}
	198
	199	/*
2d1c645c	200	* IRQ handler.
5a0015d6 CZ	201	*/
5a0015d6 CZ	202
5a0015d6 CZ	203	extern void do_IRQ(int, struct pt_regs *);
5a0015d6 CZ	204
38fef73c MF	205	#if XTENSA_FAKE_NMI
38fef73c MF	206
e4629194 MF	207	#define IS_POW2(v) (((v) & ((v) - 1)) == 0)
	208
	209	#if !(PROFILING_INTLEVEL == XCHAL_EXCM_LEVEL && \
	210	IS_POW2(XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL)))
	211	#warning "Fake NMI is requested for PMM, but there are other IRQs at or above its level."
	212	#warning "Fake NMI will be used, but there will be a bugcheck if one of those IRQs fire."
	213
	214	static inline void check_valid_nmi(void)
	215	{
	216	unsigned intread = get_sr(interrupt);
	217	unsigned intenable = get_sr(intenable);
	218
	219	BUG_ON(intread & intenable &
	220	~(XTENSA_INTLEVEL_ANDBELOW_MASK(PROFILING_INTLEVEL) ^
	221	XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL) ^
	222	BIT(XCHAL_PROFILING_INTERRUPT)));
	223	}
	224
	225	#else
	226
	227	static inline void check_valid_nmi(void)
	228	{
	229	}
	230
	231	#endif
	232
38fef73c MF	233	irqreturn_t xtensa_pmu_irq_handler(int irq, void *dev_id);
	234
	235	DEFINE_PER_CPU(unsigned long, nmi_count);
	236
	237	void do_nmi(struct pt_regs *regs)
	238	{
	239	struct pt_regs *old_regs;
	240
	241	if ((regs->ps & PS_INTLEVEL_MASK) < LOCKLEVEL)
	242	trace_hardirqs_off();
	243
	244	old_regs = set_irq_regs(regs);
	245	nmi_enter();
	246	++*this_cpu_ptr(&nmi_count);
e4629194	247	check_valid_nmi();
38fef73c MF	248	xtensa_pmu_irq_handler(0, NULL);
	249	nmi_exit();
	250	set_irq_regs(old_regs);
	251	}
	252	#endif
	253
2d1c645c	254	void do_interrupt(struct pt_regs *regs)
5a0015d6	255	{
2d1c645c MG	256	static const unsigned int_level_mask[] = {
	257	0,
	258	XCHAL_INTLEVEL1_MASK,
	259	XCHAL_INTLEVEL2_MASK,
	260	XCHAL_INTLEVEL3_MASK,
	261	XCHAL_INTLEVEL4_MASK,
	262	XCHAL_INTLEVEL5_MASK,
	263	XCHAL_INTLEVEL6_MASK,
	264	XCHAL_INTLEVEL7_MASK,
	265	};
7d5f6a9a	266	struct pt_regs *old_regs;
99623239	267
7d5f6a9a MF	268	trace_hardirqs_off();
	269
	270	old_regs = set_irq_regs(regs);
99623239	271	irq_enter();
5a0015d6	272
2d1c645c MG	273	for (;;) {
	274	unsigned intread = get_sr(interrupt);
	275	unsigned intenable = get_sr(intenable);
895666a9 MF	276	unsigned int_at_level = intread & intenable;
	277	unsigned level;
	278
	279	for (level = LOCKLEVEL; level > 0; --level) {
	280	if (int_at_level & int_level_mask[level]) {
	281	int_at_level &= int_level_mask[level];
	282	break;
	283	}
	284	}
2d1c645c	285
895666a9	286	if (level == 0)
99623239 MF	287	break;
	288
	289	do_IRQ(__ffs(int_at_level), regs);
5a0015d6	290	}
99623239 MF	291
	292	irq_exit();
	293	set_irq_regs(old_regs);
5a0015d6 CZ	294	}
	295
	296	/*
	297	* Illegal instruction. Fatal if in kernel space.
	298	*/
	299
	300	void
	301	do_illegal_instruction(struct pt_regs *regs)
	302	{
	303	__die_if_kernel("Illegal instruction in kernel", regs, SIGKILL);
	304
	305	/* If in user mode, send SIGILL signal to current process. */
	306
	307	printk("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n",
19c5870c	308	current->comm, task_pid_nr(current), regs->pc);
5a0015d6 CZ	309	force_sig(SIGILL, current);
	310	}
	311
	312
	313	/*
	314	* Handle unaligned memory accesses from user space. Kill task.
	315	*
	316	* If CONFIG_UNALIGNED_USER is not set, we don't allow unaligned memory
	317	* accesses causes from user space.
	318	*/
	319
	320	#if XCHAL_UNALIGNED_LOAD_EXCEPTION \|\| XCHAL_UNALIGNED_STORE_EXCEPTION
5a0015d6 CZ	321	void
	322	do_unaligned_user (struct pt_regs *regs)
	323	{
	324	siginfo_t info;
	325
	326	__die_if_kernel("Unhandled unaligned exception in kernel",
	327	regs, SIGKILL);
	328
	329	current->thread.bad_vaddr = regs->excvaddr;
	330	current->thread.error_code = -3;
	331	printk("Unaligned memory access to %08lx in '%s' "
	332	"(pid = %d, pc = %#010lx)\n",
19c5870c	333	regs->excvaddr, current->comm, task_pid_nr(current), regs->pc);
5a0015d6 CZ	334	info.si_signo = SIGBUS;
	335	info.si_errno = 0;
	336	info.si_code = BUS_ADRALN;
	337	info.si_addr = (void *) regs->excvaddr;
	338	force_sig_info(SIGSEGV, &info, current);
	339
	340	}
	341	#endif
5a0015d6	342
c91e02bd MF	343	/* Handle debug events.
	344	* When CONFIG_HAVE_HW_BREAKPOINT is on this handler is called with
	345	* preemption disabled to avoid rescheduling and keep mapping of hardware
	346	* breakpoint structures to debug registers intact, so that
	347	* DEBUGCAUSE.DBNUM could be used in case of data breakpoint hit.
	348	*/
5a0015d6 CZ	349	void
	350	do_debug(struct pt_regs *regs)
	351	{
c91e02bd MF	352	#ifdef CONFIG_HAVE_HW_BREAKPOINT
	353	int ret = check_hw_breakpoint(regs);
	354
	355	preempt_enable();
	356	if (ret == 0)
	357	return;
	358	#endif
5a0015d6 CZ	359	__die_if_kernel("Breakpoint in kernel", regs, SIGKILL);
	360
	361	/* If in user mode, send SIGTRAP signal to current process */
	362
	363	force_sig(SIGTRAP, current);
	364	}
	365
	366
f615136c MF	367	static void set_handler(int idx, void *handler)
	368	{
	369	unsigned int cpu;
	370
	371	for_each_possible_cpu(cpu)
	372	per_cpu(exc_table, cpu)[idx] = (unsigned long)handler;
	373	}
	374
28570e8d MF	375	/* Set exception C handler - for temporary use when probing exceptions */
	376
	377	void * __init trap_set_handler(int cause, void *handler)
	378	{
f615136c MF	379	void previous = (void )per_cpu(exc_table, 0)[
	380	EXC_TABLE_DEFAULT / 4 + cause];
	381	set_handler(EXC_TABLE_DEFAULT / 4 + cause, handler);
28570e8d MF	382	return previous;
	383	}
	384
	385
49b424fe	386	static void trap_init_excsave(void)
f615136c MF	387	{
	388	unsigned long excsave1 = (unsigned long)this_cpu_ptr(exc_table);
	389	__asm__ __volatile__("wsr %0, excsave1\n" : : "a" (excsave1));
	390	}
	391
6ec7026a MF	392	static void trap_init_debug(void)
	393	{
	394	unsigned long debugsave = (unsigned long)this_cpu_ptr(&debug_table);
	395
	396	this_cpu_ptr(&debug_table)->debug_exception = debug_exception;
	397	__asm__ __volatile__("wsr %0, excsave" __stringify(XCHAL_DEBUGLEVEL)
	398	:: "a"(debugsave));
	399	}
	400
5a0015d6 CZ	401	/*
	402	* Initialize dispatch tables.
	403	*
	404	* The exception vectors are stored compressed the __init section in the
	405	* dispatch_init_table. This function initializes the following three tables
	406	* from that compressed table:
	407	* - fast user first dispatch table for user exceptions
	408	* - fast kernel first dispatch table for kernel exceptions
	409	* - default C-handler C-handler called by the default fast handler.
	410	*
	411	* See vectors.S for more details.
	412	*/
	413
b91dc336	414	void __init trap_init(void)
5a0015d6 CZ	415	{
	416	int i;
	417
	418	/* Setup default vectors. */
	419
	420	for(i = 0; i < 64; i++) {
	421	set_handler(EXC_TABLE_FAST_USER/4 + i, user_exception);
	422	set_handler(EXC_TABLE_FAST_KERNEL/4 + i, kernel_exception);
	423	set_handler(EXC_TABLE_DEFAULT/4 + i, do_unhandled);
	424	}
	425
	426	/* Setup specific handlers. */
	427
	428	for(i = 0; dispatch_init_table[i].cause >= 0; i++) {
	429
	430	int fast = dispatch_init_table[i].fast;
	431	int cause = dispatch_init_table[i].cause;
	432	void *handler = dispatch_init_table[i].handler;
	433
	434	if (fast == 0)
	435	set_handler (EXC_TABLE_DEFAULT/4 + cause, handler);
	436	if (fast && fast & USER)
	437	set_handler (EXC_TABLE_FAST_USER/4 + cause, handler);
	438	if (fast && fast & KRNL)
	439	set_handler (EXC_TABLE_FAST_KERNEL/4 + cause, handler);
	440	}
	441
	442	/* Initialize EXCSAVE_1 to hold the address of the exception table. */
f615136c	443	trap_init_excsave();
6ec7026a	444	trap_init_debug();
f615136c	445	}
5a0015d6	446
f615136c	447	#ifdef CONFIG_SMP
49b424fe	448	void secondary_trap_init(void)
f615136c MF	449	{
f615136c MF	450	trap_init_excsave();
6ec7026a	451	trap_init_debug();
5a0015d6	452	}
f615136c	453	#endif
5a0015d6 CZ	454
	455	/*
	456	* This function dumps the current valid window frame and other base registers.
	457	*/
	458
	459	void show_regs(struct pt_regs * regs)
	460	{
	461	int i, wmask;
	462
a43cb95d TH	463	show_regs_print_info(KERN_DEFAULT);
a43cb95d TH	464
5a0015d6 CZ	465	wmask = regs->wmask & ~1;
5a0015d6 CZ	466
8d7e8240	467	for (i = 0; i < 16; i++) {
5a0015d6	468	if ((i % 8) == 0)
d4eccafc MF	469	pr_info("a%02d:", i);
d4eccafc MF	470	pr_cont(" %08lx", regs->areg[i]);
5a0015d6	471	}
d4eccafc MF	472	pr_cont("\n");
	473	pr_info("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n",
	474	regs->pc, regs->ps, regs->depc, regs->excvaddr);
	475	pr_info("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n",
	476	regs->lbeg, regs->lend, regs->lcount, regs->sar);
5a0015d6	477	if (user_mode(regs))
d4eccafc MF	478	pr_cont("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n",
	479	regs->windowbase, regs->windowstart, regs->wmask,
	480	regs->syscall);
5a0015d6 CZ	481	}
5a0015d6 CZ	482
3e4196a5	483	static int show_trace_cb(struct stackframe frame, void data)
586411dc	484	{
3e4196a5	485	if (kernel_text_address(frame->pc)) {
d4eccafc MF	486	pr_cont(" [<%08lx>]", frame->pc);
d4eccafc MF	487	print_symbol(" %s\n", frame->pc);
3e4196a5 MF	488	}
3e4196a5 MF	489	return 0;
586411dc JW	490	}
586411dc JW	491
5a0015d6 CZ	492	void show_trace(struct task_struct task, unsigned long sp)
5a0015d6 CZ	493	{
3e4196a5 MF	494	if (!sp)
3e4196a5 MF	495	sp = stack_pointer(task);
5a0015d6	496
d4eccafc	497	pr_info("Call Trace:\n");
3e4196a5	498	walk_stackframe(sp, show_trace_cb, NULL);
d4eccafc MF	499	#ifndef CONFIG_KALLSYMS
	500	pr_cont("\n");
	501	#endif
5a0015d6 CZ	502	}
5a0015d6 CZ	503
5a0015d6 CZ	504	static int kstack_depth_to_print = 24;
	505
	506	void show_stack(struct task_struct task, unsigned long sp)
	507	{
	508	int i = 0;
	509	unsigned long *stack;
	510
28a0ce7f	511	if (!sp)
586411dc	512	sp = stack_pointer(task);
c4c4594b	513	stack = sp;
5a0015d6	514
d4eccafc	515	pr_info("Stack:\n");
5a0015d6 CZ	516
	517	for (i = 0; i < kstack_depth_to_print; i++) {
	518	if (kstack_end(sp))
	519	break;
d4eccafc MF	520	pr_cont(" %08lx", *sp++);
	521	if (i % 8 == 7)
	522	pr_cont("\n");
5a0015d6	523	}
5a0015d6 CZ	524	show_trace(task, stack);
	525	}
	526
34af946a	527	DEFINE_SPINLOCK(die_lock);
5a0015d6 CZ	528
	529	void die(const char * str, struct pt_regs * regs, long err)
	530	{
	531	static int die_counter;
5a0015d6 CZ	532
	533	console_verbose();
	534	spin_lock_irq(&die_lock);
	535
d4eccafc MF	536	pr_info("%s: sig: %ld [#%d]%s\n", str, err, ++die_counter,
d4eccafc MF	537	IS_ENABLED(CONFIG_PREEMPT) ? " PREEMPT" : "");
5a0015d6 CZ	538	show_regs(regs);
	539	if (!user_mode(regs))
	540	show_stack(NULL, (unsigned long*)regs->areg[1]);
	541
373d4d09	542	add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
5a0015d6 CZ	543	spin_unlock_irq(&die_lock);
	544
	545	if (in_interrupt())
	546	panic("Fatal exception in interrupt");
	547
cea6a4ba	548	if (panic_on_oops)
012c437d	549	panic("Fatal exception");
cea6a4ba	550
5a0015d6 CZ	551	do_exit(err);
5a0015d6 CZ	552	}