LXR linux/arch/xtensa/include/asm/traps.h

   1/*
   2 * arch/xtensa/include/asm/traps.h
   3 *
   4 * This file is subject to the terms and conditions of the GNU General Public
   5 * License.  See the file "COPYING" in the main directory of this archive
   6 * for more details.
   7 *
   8 * Copyright (C) 2012 Tensilica Inc.
   9 */
  10#ifndef _XTENSA_TRAPS_H
  11#define _XTENSA_TRAPS_H
  12
  13#include <asm/ptrace.h>
  14
  15/*
  16 * Per-CPU exception handling data structure.
  17 * EXCSAVE1 points to it.
  18 */
  19struct exc_table {
  20        /* Kernel Stack */
  21        void *kstk;
  22        /* Double exception save area for a0 */
  23        unsigned long double_save;
  24        /* Fixup handler */
  25        void *fixup;
  26        /* For passing a parameter to fixup */
  27        void *fixup_param;
  28        /* For fast syscall handler */
  29        unsigned long syscall_save;
  30        /* Fast user exception handlers */
  31        void *fast_user_handler[EXCCAUSE_N];
  32        /* Fast kernel exception handlers */
  33        void *fast_kernel_handler[EXCCAUSE_N];
  34        /* Default C-Handlers */
  35        void *default_handler[EXCCAUSE_N];
  36};
  37
  38/*
  39 * handler must be either of the following:
  40 *  void (*)(struct pt_regs *regs);
  41 *  void (*)(struct pt_regs *regs, unsigned long exccause);
  42 */
  43extern void * __init trap_set_handler(int cause, void *handler);
  44extern void do_unhandled(struct pt_regs *regs, unsigned long exccause);
  45void fast_second_level_miss(void);
  46
  47/* Initialize minimal exc_table structure sufficient for basic paging */
  48static inline void __init early_trap_init(void)
  49{
  50        static struct exc_table exc_table __initdata = {
  51                .fast_kernel_handler[EXCCAUSE_DTLB_MISS] =
  52                        fast_second_level_miss,
  53        };
  54        __asm__ __volatile__("wsr  %0, excsave1\n" : : "a" (&exc_table));
  55}
  56
  57void secondary_trap_init(void);
  58
  59static inline void spill_registers(void)
  60{
  61#if XCHAL_NUM_AREGS > 16
  62        __asm__ __volatile__ (
  63                "       call8   1f\n"
  64                "       _j      2f\n"
  65                "       retw\n"
  66                "       .align  4\n"
  67                "1:\n"
  68#if XCHAL_NUM_AREGS == 32
  69                "       _entry  a1, 32\n"
  70                "       addi    a8, a0, 3\n"
  71                "       _entry  a1, 16\n"
  72                "       mov     a12, a12\n"
  73                "       retw\n"
  74#else
  75                "       _entry  a1, 48\n"
  76                "       call12  1f\n"
  77                "       retw\n"
  78                "       .align  4\n"
  79                "1:\n"
  80                "       .rept   (" __stringify(XCHAL_NUM_AREGS) " - 16) / 12\n"
  81                "       _entry  a1, 48\n"
  82                "       mov     a12, a0\n"
  83                "       .endr\n"
  84                "       _entry  a1, 16\n"
  85#if XCHAL_NUM_AREGS % 12 == 0
  86                "       mov     a12, a12\n"
  87#elif XCHAL_NUM_AREGS % 12 == 4
  88                "       mov     a4, a4\n"
  89#elif XCHAL_NUM_AREGS % 12 == 8
  90                "       mov     a8, a8\n"
  91#endif
  92                "       retw\n"
  93#endif
  94                "2:\n"
  95                : : : "a8", "a9", "memory");
  96#else
  97        __asm__ __volatile__ (
  98                "       mov     a12, a12\n"
  99                : : : "memory");
 100#endif
 101}
 102
 103struct debug_table {
 104        /* Pointer to debug exception handler */
 105        void (*debug_exception)(void);
 106        /* Temporary register save area */
 107        unsigned long debug_save[1];
 108#ifdef CONFIG_HAVE_HW_BREAKPOINT
 109        /* Save area for DBREAKC registers */
 110        unsigned long dbreakc_save[XCHAL_NUM_DBREAK];
 111        /* Saved ICOUNT register */
 112        unsigned long icount_save;
 113        /* Saved ICOUNTLEVEL register */
 114        unsigned long icount_level_save;
 115#endif
 116};
 117
 118void debug_exception(void);
 119
 120#endif /* _XTENSA_TRAPS_H */
 121