[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/sched/task_stack.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>] %pB\n", frame->pc, (void *)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>
3f8c2452	29	#include <linux/sched/task_stack.h>
5a0015d6 CZ	30	#include <linux/init.h>
	31	#include <linux/module.h>
	32	#include <linux/stringify.h>
	33	#include <linux/kallsyms.h>
5c888d53	34	#include <linux/delay.h>
5a891ed5	35	#include <linux/hardirq.h>
5a0015d6	36
3e4196a5	37	#include <asm/stacktrace.h>
5a0015d6 CZ	38	#include <asm/ptrace.h>
5a0015d6 CZ	39	#include <asm/timex.h>
7c0f6ba6	40	#include <linux/uaccess.h>
5a0015d6 CZ	41	#include <asm/pgtable.h>
5a0015d6 CZ	42	#include <asm/processor.h>
2d6f82fe	43	#include <asm/traps.h>
c91e02bd	44	#include <asm/hw_breakpoint.h>
5a0015d6	45
5a0015d6 CZ	46	/*
	47	* Machine specific interrupt handlers
	48	*/
	49
	50	extern void kernel_exception(void);
	51	extern void user_exception(void);
	52
	53	extern void fast_syscall_kernel(void);
	54	extern void fast_syscall_user(void);
	55	extern void fast_alloca(void);
	56	extern void fast_unaligned(void);
	57	extern void fast_second_level_miss(void);
	58	extern void fast_store_prohibited(void);
	59	extern void fast_coprocessor(void);
	60
	61	extern void do_illegal_instruction (struct pt_regs*);
	62	extern void do_interrupt (struct pt_regs*);
38fef73c	63	extern void do_nmi(struct pt_regs *);
5a0015d6 CZ	64	extern void do_unaligned_user (struct pt_regs*);
	65	extern void do_multihit (struct pt_regs*, unsigned long);
	66	extern void do_page_fault (struct pt_regs*, unsigned long);
	67	extern void do_debug (struct pt_regs*);
	68	extern void system_call (struct pt_regs*);
	69
	70	/*
	71	* The vector table must be preceded by a save area (which
	72	* implies it must be in RAM, unless one places RAM immediately
	73	* before a ROM and puts the vector at the start of the ROM (!))
	74	*/
	75
	76	#define KRNL 0x01
	77	#define USER 0x02
	78
	79	#define COPROCESSOR(x) \
173d6681	80	{ EXCCAUSE_COPROCESSOR ## x ## _DISABLED, USER, fast_coprocessor }
5a0015d6 CZ	81
	82	typedef struct {
	83	int cause;
	84	int fast;
	85	void* handler;
	86	} dispatch_init_table_t;
	87
b91dc336	88	static dispatch_init_table_t __initdata dispatch_init_table[] = {
5a0015d6	89
173d6681 CZ	90	{ EXCCAUSE_ILLEGAL_INSTRUCTION, 0, do_illegal_instruction},
	91	{ EXCCAUSE_SYSTEM_CALL, KRNL, fast_syscall_kernel },
	92	{ EXCCAUSE_SYSTEM_CALL, USER, fast_syscall_user },
	93	{ EXCCAUSE_SYSTEM_CALL, 0, system_call },
	94	/* EXCCAUSE_INSTRUCTION_FETCH unhandled */
	95	/* EXCCAUSE_LOAD_STORE_ERROR unhandled*/
	96	{ EXCCAUSE_LEVEL1_INTERRUPT, 0, do_interrupt },
	97	{ EXCCAUSE_ALLOCA, USER\|KRNL, fast_alloca },
	98	/* EXCCAUSE_INTEGER_DIVIDE_BY_ZERO unhandled */
	99	/* EXCCAUSE_PRIVILEGED unhandled */
5a0015d6	100	#if XCHAL_UNALIGNED_LOAD_EXCEPTION \|\| XCHAL_UNALIGNED_STORE_EXCEPTION
4ded6282	101	#ifdef CONFIG_XTENSA_UNALIGNED_USER
173d6681	102	{ EXCCAUSE_UNALIGNED, USER, fast_unaligned },
5a0015d6	103	#endif
3cfc096e	104	{ EXCCAUSE_UNALIGNED, 0, do_unaligned_user },
173d6681	105	{ EXCCAUSE_UNALIGNED, KRNL, fast_unaligned },
5a0015d6	106	#endif
e5083a63	107	#ifdef CONFIG_MMU
173d6681 CZ	108	{ EXCCAUSE_ITLB_MISS, 0, do_page_fault },
	109	{ EXCCAUSE_ITLB_MISS, USER\|KRNL, fast_second_level_miss},
	110	{ EXCCAUSE_ITLB_MULTIHIT, 0, do_multihit },
	111	{ EXCCAUSE_ITLB_PRIVILEGE, 0, do_page_fault },
	112	/* EXCCAUSE_SIZE_RESTRICTION unhandled */
	113	{ EXCCAUSE_FETCH_CACHE_ATTRIBUTE, 0, do_page_fault },
	114	{ EXCCAUSE_DTLB_MISS, USER\|KRNL, fast_second_level_miss},
	115	{ EXCCAUSE_DTLB_MISS, 0, do_page_fault },
	116	{ EXCCAUSE_DTLB_MULTIHIT, 0, do_multihit },
	117	{ EXCCAUSE_DTLB_PRIVILEGE, 0, do_page_fault },
	118	/* EXCCAUSE_DTLB_SIZE_RESTRICTION unhandled */
	119	{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, USER\|KRNL, fast_store_prohibited },
	120	{ EXCCAUSE_STORE_CACHE_ATTRIBUTE, 0, do_page_fault },
	121	{ EXCCAUSE_LOAD_CACHE_ATTRIBUTE, 0, do_page_fault },
e5083a63	122	#endif /* CONFIG_MMU */
5a0015d6	123	/* XCCHAL_EXCCAUSE_FLOATING_POINT unhandled */
c658eac6	124	#if XTENSA_HAVE_COPROCESSOR(0)
5a0015d6 CZ	125	COPROCESSOR(0),
5a0015d6 CZ	126	#endif
c658eac6	127	#if XTENSA_HAVE_COPROCESSOR(1)
5a0015d6 CZ	128	COPROCESSOR(1),
5a0015d6 CZ	129	#endif
c658eac6	130	#if XTENSA_HAVE_COPROCESSOR(2)
5a0015d6 CZ	131	COPROCESSOR(2),
5a0015d6 CZ	132	#endif
c658eac6	133	#if XTENSA_HAVE_COPROCESSOR(3)
5a0015d6 CZ	134	COPROCESSOR(3),
5a0015d6 CZ	135	#endif
c658eac6	136	#if XTENSA_HAVE_COPROCESSOR(4)
5a0015d6 CZ	137	COPROCESSOR(4),
5a0015d6 CZ	138	#endif
c658eac6	139	#if XTENSA_HAVE_COPROCESSOR(5)
5a0015d6 CZ	140	COPROCESSOR(5),
5a0015d6 CZ	141	#endif
c658eac6	142	#if XTENSA_HAVE_COPROCESSOR(6)
5a0015d6 CZ	143	COPROCESSOR(6),
5a0015d6 CZ	144	#endif
c658eac6	145	#if XTENSA_HAVE_COPROCESSOR(7)
5a0015d6 CZ	146	COPROCESSOR(7),
5a0015d6 CZ	147	#endif
38fef73c MF	148	#if XTENSA_FAKE_NMI
	149	{ EXCCAUSE_MAPPED_NMI, 0, do_nmi },
	150	#endif
5a0015d6 CZ	151	{ EXCCAUSE_MAPPED_DEBUG, 0, do_debug },
	152	{ -1, -1, 0 }
	153
	154	};
	155
	156	/* The exception table <exc_table> serves two functions:
	157	* 1. it contains three dispatch tables (fast_user, fast_kernel, default-c)
	158	* 2. it is a temporary memory buffer for the exception handlers.
	159	*/
	160
f615136c	161	DEFINE_PER_CPU(unsigned long, exc_table[EXC_TABLE_SIZE/4]);
5a0015d6	162
6ec7026a MF	163	DEFINE_PER_CPU(struct debug_table, debug_table);
6ec7026a MF	164
5a0015d6 CZ	165	void die(const char, struct pt_regs, long);
	166
	167	static inline void
	168	__die_if_kernel(const char str, struct pt_regs regs, long err)
	169	{
	170	if (!user_mode(regs))
	171	die(str, regs, err);
	172	}
	173
	174	/*
	175	* Unhandled Exceptions. Kill user task or panic if in kernel space.
	176	*/
	177
	178	void do_unhandled(struct pt_regs *regs, unsigned long exccause)
	179	{
	180	__die_if_kernel("Caught unhandled exception - should not happen",
	181	regs, SIGKILL);
	182
	183	/* If in user mode, send SIGILL signal to current process */
	184	printk("Caught unhandled exception in '%s' "
	185	"(pid = %d, pc = %#010lx) - should not happen\n"
	186	"\tEXCCAUSE is %ld\n",
19c5870c	187	current->comm, task_pid_nr(current), regs->pc, exccause);
5a0015d6 CZ	188	force_sig(SIGILL, current);
	189	}
	190
	191	/*
	192	* Multi-hit exception. This if fatal!
	193	*/
	194
	195	void do_multihit(struct pt_regs *regs, unsigned long exccause)
	196	{
	197	die("Caught multihit exception", regs, SIGKILL);
	198	}
	199
	200	/*
2d1c645c	201	* IRQ handler.
5a0015d6 CZ	202	*/
5a0015d6 CZ	203
5a0015d6 CZ	204	extern void do_IRQ(int, struct pt_regs *);
5a0015d6 CZ	205
38fef73c MF	206	#if XTENSA_FAKE_NMI
38fef73c MF	207
e4629194 MF	208	#define IS_POW2(v) (((v) & ((v) - 1)) == 0)
	209
	210	#if !(PROFILING_INTLEVEL == XCHAL_EXCM_LEVEL && \
	211	IS_POW2(XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL)))
	212	#warning "Fake NMI is requested for PMM, but there are other IRQs at or above its level."
	213	#warning "Fake NMI will be used, but there will be a bugcheck if one of those IRQs fire."
	214
	215	static inline void check_valid_nmi(void)
	216	{
	217	unsigned intread = get_sr(interrupt);
	218	unsigned intenable = get_sr(intenable);
	219
	220	BUG_ON(intread & intenable &
	221	~(XTENSA_INTLEVEL_ANDBELOW_MASK(PROFILING_INTLEVEL) ^
	222	XTENSA_INTLEVEL_MASK(PROFILING_INTLEVEL) ^
	223	BIT(XCHAL_PROFILING_INTERRUPT)));
	224	}
	225
	226	#else
	227
	228	static inline void check_valid_nmi(void)
	229	{
	230	}
	231
	232	#endif
	233
38fef73c MF	234	irqreturn_t xtensa_pmu_irq_handler(int irq, void *dev_id);
	235
	236	DEFINE_PER_CPU(unsigned long, nmi_count);
	237
	238	void do_nmi(struct pt_regs *regs)
	239	{
	240	struct pt_regs *old_regs;
	241
	242	if ((regs->ps & PS_INTLEVEL_MASK) < LOCKLEVEL)
	243	trace_hardirqs_off();
	244
	245	old_regs = set_irq_regs(regs);
	246	nmi_enter();
	247	++*this_cpu_ptr(&nmi_count);
e4629194	248	check_valid_nmi();
38fef73c MF	249	xtensa_pmu_irq_handler(0, NULL);
	250	nmi_exit();
	251	set_irq_regs(old_regs);
	252	}
	253	#endif
	254
2d1c645c	255	void do_interrupt(struct pt_regs *regs)
5a0015d6	256	{
2d1c645c MG	257	static const unsigned int_level_mask[] = {
	258	0,
	259	XCHAL_INTLEVEL1_MASK,
	260	XCHAL_INTLEVEL2_MASK,
	261	XCHAL_INTLEVEL3_MASK,
	262	XCHAL_INTLEVEL4_MASK,
	263	XCHAL_INTLEVEL5_MASK,
	264	XCHAL_INTLEVEL6_MASK,
	265	XCHAL_INTLEVEL7_MASK,
	266	};
7d5f6a9a	267	struct pt_regs *old_regs;
99623239	268
7d5f6a9a MF	269	trace_hardirqs_off();
	270
	271	old_regs = set_irq_regs(regs);
99623239	272	irq_enter();
5a0015d6	273
2d1c645c MG	274	for (;;) {
	275	unsigned intread = get_sr(interrupt);
	276	unsigned intenable = get_sr(intenable);
895666a9 MF	277	unsigned int_at_level = intread & intenable;
	278	unsigned level;
	279
	280	for (level = LOCKLEVEL; level > 0; --level) {
	281	if (int_at_level & int_level_mask[level]) {
	282	int_at_level &= int_level_mask[level];
	283	break;
	284	}
	285	}
2d1c645c	286
895666a9	287	if (level == 0)
99623239 MF	288	break;
	289
	290	do_IRQ(__ffs(int_at_level), regs);
5a0015d6	291	}
99623239 MF	292
	293	irq_exit();
	294	set_irq_regs(old_regs);
5a0015d6 CZ	295	}
	296
	297	/*
	298	* Illegal instruction. Fatal if in kernel space.
	299	*/
	300
	301	void
	302	do_illegal_instruction(struct pt_regs *regs)
	303	{
	304	__die_if_kernel("Illegal instruction in kernel", regs, SIGKILL);
	305
	306	/* If in user mode, send SIGILL signal to current process. */
	307
	308	printk("Illegal Instruction in '%s' (pid = %d, pc = %#010lx)\n",
19c5870c	309	current->comm, task_pid_nr(current), regs->pc);
5a0015d6 CZ	310	force_sig(SIGILL, current);
	311	}
	312
	313
	314	/*
	315	* Handle unaligned memory accesses from user space. Kill task.
	316	*
	317	* If CONFIG_UNALIGNED_USER is not set, we don't allow unaligned memory
	318	* accesses causes from user space.
	319	*/
	320
	321	#if XCHAL_UNALIGNED_LOAD_EXCEPTION \|\| XCHAL_UNALIGNED_STORE_EXCEPTION
5a0015d6 CZ	322	void
	323	do_unaligned_user (struct pt_regs *regs)
	324	{
	325	siginfo_t info;
	326
	327	__die_if_kernel("Unhandled unaligned exception in kernel",
	328	regs, SIGKILL);
	329
	330	current->thread.bad_vaddr = regs->excvaddr;
	331	current->thread.error_code = -3;
	332	printk("Unaligned memory access to %08lx in '%s' "
	333	"(pid = %d, pc = %#010lx)\n",
19c5870c	334	regs->excvaddr, current->comm, task_pid_nr(current), regs->pc);
5a0015d6 CZ	335	info.si_signo = SIGBUS;
	336	info.si_errno = 0;
	337	info.si_code = BUS_ADRALN;
	338	info.si_addr = (void *) regs->excvaddr;
	339	force_sig_info(SIGSEGV, &info, current);
	340
	341	}
	342	#endif
5a0015d6	343
c91e02bd MF	344	/* Handle debug events.
	345	* When CONFIG_HAVE_HW_BREAKPOINT is on this handler is called with
	346	* preemption disabled to avoid rescheduling and keep mapping of hardware
	347	* breakpoint structures to debug registers intact, so that
	348	* DEBUGCAUSE.DBNUM could be used in case of data breakpoint hit.
	349	*/
5a0015d6 CZ	350	void
	351	do_debug(struct pt_regs *regs)
	352	{
c91e02bd MF	353	#ifdef CONFIG_HAVE_HW_BREAKPOINT
	354	int ret = check_hw_breakpoint(regs);
	355
	356	preempt_enable();
	357	if (ret == 0)
	358	return;
	359	#endif
5a0015d6 CZ	360	__die_if_kernel("Breakpoint in kernel", regs, SIGKILL);
	361
	362	/* If in user mode, send SIGTRAP signal to current process */
	363
	364	force_sig(SIGTRAP, current);
	365	}
	366
	367
f615136c MF	368	static void set_handler(int idx, void *handler)
	369	{
	370	unsigned int cpu;
	371
	372	for_each_possible_cpu(cpu)
	373	per_cpu(exc_table, cpu)[idx] = (unsigned long)handler;
	374	}
	375
28570e8d MF	376	/* Set exception C handler - for temporary use when probing exceptions */
	377
	378	void * __init trap_set_handler(int cause, void *handler)
	379	{
f615136c MF	380	void previous = (void )per_cpu(exc_table, 0)[
	381	EXC_TABLE_DEFAULT / 4 + cause];
	382	set_handler(EXC_TABLE_DEFAULT / 4 + cause, handler);
28570e8d MF	383	return previous;
	384	}
	385
	386
49b424fe	387	static void trap_init_excsave(void)
f615136c MF	388	{
	389	unsigned long excsave1 = (unsigned long)this_cpu_ptr(exc_table);
	390	__asm__ __volatile__("wsr %0, excsave1\n" : : "a" (excsave1));
	391	}
	392
6ec7026a MF	393	static void trap_init_debug(void)
	394	{
	395	unsigned long debugsave = (unsigned long)this_cpu_ptr(&debug_table);
	396
	397	this_cpu_ptr(&debug_table)->debug_exception = debug_exception;
	398	__asm__ __volatile__("wsr %0, excsave" __stringify(XCHAL_DEBUGLEVEL)
	399	:: "a"(debugsave));
	400	}
	401
5a0015d6 CZ	402	/*
	403	* Initialize dispatch tables.
	404	*
	405	* The exception vectors are stored compressed the __init section in the
	406	* dispatch_init_table. This function initializes the following three tables
	407	* from that compressed table:
	408	* - fast user first dispatch table for user exceptions
	409	* - fast kernel first dispatch table for kernel exceptions
	410	* - default C-handler C-handler called by the default fast handler.
	411	*
	412	* See vectors.S for more details.
	413	*/
	414
b91dc336	415	void __init trap_init(void)
5a0015d6 CZ	416	{
	417	int i;
	418
	419	/* Setup default vectors. */
	420
	421	for(i = 0; i < 64; i++) {
	422	set_handler(EXC_TABLE_FAST_USER/4 + i, user_exception);
	423	set_handler(EXC_TABLE_FAST_KERNEL/4 + i, kernel_exception);
	424	set_handler(EXC_TABLE_DEFAULT/4 + i, do_unhandled);
	425	}
	426
	427	/* Setup specific handlers. */
	428
	429	for(i = 0; dispatch_init_table[i].cause >= 0; i++) {
	430
	431	int fast = dispatch_init_table[i].fast;
	432	int cause = dispatch_init_table[i].cause;
	433	void *handler = dispatch_init_table[i].handler;
	434
	435	if (fast == 0)
	436	set_handler (EXC_TABLE_DEFAULT/4 + cause, handler);
	437	if (fast && fast & USER)
	438	set_handler (EXC_TABLE_FAST_USER/4 + cause, handler);
	439	if (fast && fast & KRNL)
	440	set_handler (EXC_TABLE_FAST_KERNEL/4 + cause, handler);
	441	}
	442
	443	/* Initialize EXCSAVE_1 to hold the address of the exception table. */
f615136c	444	trap_init_excsave();
6ec7026a	445	trap_init_debug();
f615136c	446	}
5a0015d6	447
f615136c	448	#ifdef CONFIG_SMP
49b424fe	449	void secondary_trap_init(void)
f615136c MF	450	{
f615136c MF	451	trap_init_excsave();
6ec7026a	452	trap_init_debug();
5a0015d6	453	}
f615136c	454	#endif
5a0015d6 CZ	455
	456	/*
	457	* This function dumps the current valid window frame and other base registers.
	458	*/
	459
	460	void show_regs(struct pt_regs * regs)
	461	{
	462	int i, wmask;
	463
a43cb95d TH	464	show_regs_print_info(KERN_DEFAULT);
a43cb95d TH	465
5a0015d6 CZ	466	wmask = regs->wmask & ~1;
5a0015d6 CZ	467
8d7e8240	468	for (i = 0; i < 16; i++) {
5a0015d6	469	if ((i % 8) == 0)
d4eccafc MF	470	pr_info("a%02d:", i);
d4eccafc MF	471	pr_cont(" %08lx", regs->areg[i]);
5a0015d6	472	}
d4eccafc MF	473	pr_cont("\n");
	474	pr_info("pc: %08lx, ps: %08lx, depc: %08lx, excvaddr: %08lx\n",
	475	regs->pc, regs->ps, regs->depc, regs->excvaddr);
	476	pr_info("lbeg: %08lx, lend: %08lx lcount: %08lx, sar: %08lx\n",
	477	regs->lbeg, regs->lend, regs->lcount, regs->sar);
5a0015d6	478	if (user_mode(regs))
d4eccafc MF	479	pr_cont("wb: %08lx, ws: %08lx, wmask: %08lx, syscall: %ld\n",
	480	regs->windowbase, regs->windowstart, regs->wmask,
	481	regs->syscall);
5a0015d6 CZ	482	}
5a0015d6 CZ	483
3e4196a5	484	static int show_trace_cb(struct stackframe frame, void data)
586411dc	485	{
e640cc30 MF	486	if (kernel_text_address(frame->pc))
e640cc30 MF	487	pr_cont(" [<%08lx>] %pB\n", frame->pc, (void *)frame->pc);
3e4196a5	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	}