LXR linux/arch/m68k/include/asm/entry

   1#ifndef __M68K_ENTRY_H
   2#define __M68K_ENTRY_H
   3
   4#include <asm/setup.h>
   5#include <asm/page.h>
   6
   7/*
   8 * Stack layout in 'ret_from_exception':
   9 *
  10 *      This allows access to the syscall arguments in registers d1-d5
  11 *
  12 *       0(sp) - d1
  13 *       4(sp) - d2
  14 *       8(sp) - d3
  15 *       C(sp) - d4
  16 *      10(sp) - d5
  17 *      14(sp) - a0
  18 *      18(sp) - a1
  19 *      1C(sp) - a2
  20 *      20(sp) - d0
  21 *      24(sp) - orig_d0
  22 *      28(sp) - stack adjustment
  23 *      2C(sp) - sr
  24 *      2E(sp) - pc
  25 *      32(sp) - format & vector
  26 */
  27
  28/*
  29 * 97/05/14 Andreas: Register %a2 is now set to the current task throughout
  30 *                   the whole kernel.
  31 */
  32
  33/* the following macro is used when enabling interrupts */
  34#if defined(MACH_ATARI_ONLY)
  35        /* block out HSYNC on the atari */
  36#define ALLOWINT        (~0x400)
  37#define MAX_NOINT_IPL   3
  38#else
  39        /* portable version */
  40#define ALLOWINT        (~0x700)
  41#define MAX_NOINT_IPL   0
  42#endif /* machine compilation types */
  43
  44#ifdef __ASSEMBLY__
  45
  46#define curptr a2
  47
  48LFLUSH_I_AND_D = 0x00000808
  49
  50/* process bits for task_struct.ptrace */
  51PT_TRACESYS_OFF = 3
  52PT_TRACESYS_BIT = 1
  53PT_PTRACED_OFF = 3
  54PT_PTRACED_BIT = 0
  55PT_DTRACE_OFF = 3
  56PT_DTRACE_BIT = 2
  57
  58#define SAVE_ALL_INT save_all_int
  59#define SAVE_ALL_SYS save_all_sys
  60#define RESTORE_ALL restore_all
  61/*
  62 * This defines the normal kernel pt-regs layout.
  63 *
  64 * regs a3-a6 and d6-d7 are preserved by C code
  65 * the kernel doesn't mess with usp unless it needs to
  66 */
  67
  68/*
  69 * a -1 in the orig_d0 field signifies
  70 * that the stack frame is NOT for syscall
  71 */
  72.macro  save_all_int
  73        clrl    %sp@-           | stk_adj
  74        pea     -1:w            | orig d0
  75        movel   %d0,%sp@-       | d0
  76        moveml  %d1-%d5/%a0-%a1/%curptr,%sp@-
  77.endm
  78
  79.macro  save_all_sys
  80        clrl    %sp@-           | stk_adj
  81        movel   %d0,%sp@-       | orig d0
  82        movel   %d0,%sp@-       | d0
  83        moveml  %d1-%d5/%a0-%a1/%curptr,%sp@-
  84.endm
  85
  86.macro  restore_all
  87        moveml  %sp@+,%a0-%a1/%curptr/%d1-%d5
  88        movel   %sp@+,%d0
  89        addql   #4,%sp          | orig d0
  90        addl    %sp@+,%sp       | stk adj
  91        rte
  92.endm
  93
  94#define SWITCH_STACK_SIZE (6*4+4)       /* includes return address */
  95
  96#define SAVE_SWITCH_STACK save_switch_stack
  97#define RESTORE_SWITCH_STACK restore_switch_stack
  98#define GET_CURRENT(tmp) get_current tmp
  99
 100.macro  save_switch_stack
 101        moveml  %a3-%a6/%d6-%d7,%sp@-
 102.endm
 103
 104.macro  restore_switch_stack
 105        moveml  %sp@+,%a3-%a6/%d6-%d7
 106.endm
 107
 108.macro  get_current reg=%d0
 109        movel   %sp,\reg
 110        andw    #-THREAD_SIZE,\reg
 111        movel   \reg,%curptr
 112        movel   %curptr@,%curptr
 113.endm
 114
 115#else /* C source */
 116
 117#define STR(X) STR1(X)
 118#define STR1(X) #X
 119
 120#define SAVE_ALL_INT                            \
 121        "clrl   %%sp@-;"    /* stk_adj */       \
 122        "pea    -1:w;"      /* orig d0 = -1 */  \
 123        "movel  %%d0,%%sp@-;" /* d0 */          \
 124        "moveml %%d1-%%d5/%%a0-%%a2,%%sp@-"
 125#define GET_CURRENT(tmp) \
 126        "movel  %%sp,"#tmp"\n\t" \
 127        "andw   #-"STR(THREAD_SIZE)","#tmp"\n\t" \
 128        "movel  "#tmp",%%a2\n\t" \
 129        "movel  %%a2@,%%a2"
 130
 131#endif
 132
 133#endif /* __M68K_ENTRY_H */
 134