root/arch/xtensa/include/asm/traps.h

INCLUDED FROM

DEFINITIONS

1. early_trap_init
2. spill_registers

   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  */
  19 struct 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         /* Fast user exception handlers */
  29         void *fast_user_handler[EXCCAUSE_N];
  30         /* Fast kernel exception handlers */
  31         void *fast_kernel_handler[EXCCAUSE_N];
  32         /* Default C-Handlers */
  33         void *default_handler[EXCCAUSE_N];
  34 };
  35 
  36 /*
  37  * handler must be either of the following:
  38  *  void (*)(struct pt_regs *regs);
  39  *  void (*)(struct pt_regs *regs, unsigned long exccause);
  40  */
  41 extern void * __init trap_set_handler(int cause, void *handler);
  42 extern void do_unhandled(struct pt_regs *regs, unsigned long exccause);
  43 void fast_second_level_miss(void);
  44 
  45 /* Initialize minimal exc_table structure sufficient for basic paging */
  46 static inline void __init early_trap_init(void)
  47 {
  48         static struct exc_table exc_table __initdata = {
  49                 .fast_kernel_handler[EXCCAUSE_DTLB_MISS] =
  50                         fast_second_level_miss,
  51         };
  52         __asm__ __volatile__("wsr  %0, excsave1\n" : : "a" (&exc_table));
  53 }
  54 
  55 void secondary_trap_init(void);
  56 
  57 static inline void spill_registers(void)
  58 {
  59 #if XCHAL_NUM_AREGS > 16
  60         __asm__ __volatile__ (
  61                 "       call8   1f\n"
  62                 "       _j      2f\n"
  63                 "       retw\n"
  64                 "       .align  4\n"
  65                 "1:\n"
  66 #if XCHAL_NUM_AREGS == 32
  67                 "       _entry  a1, 32\n"
  68                 "       addi    a8, a0, 3\n"
  69                 "       _entry  a1, 16\n"
  70                 "       mov     a12, a12\n"
  71                 "       retw\n"
  72 #else
  73                 "       _entry  a1, 48\n"
  74                 "       call12  1f\n"
  75                 "       retw\n"
  76                 "       .align  4\n"
  77                 "1:\n"
  78                 "       .rept   (" __stringify(XCHAL_NUM_AREGS) " - 16) / 12\n"
  79                 "       _entry  a1, 48\n"
  80                 "       mov     a12, a0\n"
  81                 "       .endr\n"
  82                 "       _entry  a1, 16\n"
  83 #if XCHAL_NUM_AREGS % 12 == 0
  84                 "       mov     a12, a12\n"
  85 #elif XCHAL_NUM_AREGS % 12 == 4
  86                 "       mov     a4, a4\n"
  87 #elif XCHAL_NUM_AREGS % 12 == 8
  88                 "       mov     a8, a8\n"
  89 #endif
  90                 "       retw\n"
  91 #endif
  92                 "2:\n"
  93                 : : : "a8", "a9", "memory");
  94 #else
  95         __asm__ __volatile__ (
  96                 "       mov     a12, a12\n"
  97                 : : : "memory");
  98 #endif
  99 }
 100 
 101 struct debug_table {
 102         /* Pointer to debug exception handler */
 103         void (*debug_exception)(void);
 104         /* Temporary register save area */
 105         unsigned long debug_save[1];
 106 #ifdef CONFIG_HAVE_HW_BREAKPOINT
 107         /* Save area for DBREAKC registers */
 108         unsigned long dbreakc_save[XCHAL_NUM_DBREAK];
 109         /* Saved ICOUNT register */
 110         unsigned long icount_save;
 111         /* Saved ICOUNTLEVEL register */
 112         unsigned long icount_level_save;
 113 #endif
 114 };
 115 
 116 void debug_exception(void);
 117 
 118 #endif /* _XTENSA_TRAPS_H */