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  */
  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         /* 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  */
  43 extern void * __init trap_set_handler(int cause, void *handler);
  44 extern void do_unhandled(struct pt_regs *regs, unsigned long exccause);
  45 void fast_second_level_miss(void);
  46
  47 /* Initialize minimal exc_table structure sufficient for basic paging */
  48 static 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
  57 void secondary_trap_init(void);
  58
  59 static 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
 103 struct 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
 118 void debug_exception(void);
 119
 120 #endif /* _XTENSA_TRAPS_H */