include/asm-m68knommu/entry.h

   1 #ifndef __M68KNOMMU_ENTRY_H
   2 #define __M68KNOMMU_ENTRY_H
   3
   4 #include <linux/config.h>
   5 #include <asm/setup.h>
   6 #include <asm/page.h>
   7
   8 /*
   9  * Stack layout in 'ret_from_exception':
  10  *
  11  * This allows access to the syscall arguments in registers d1-d5
  12  *
  13  *       0(sp) - d1
  14  *       4(sp) - d2
  15  *       8(sp) - d3
  16  *       C(sp) - d4
  17  *      10(sp) - d5
  18  *      14(sp) - a0
  19  *      18(sp) - a1
  20  *      1C(sp) - a2
  21  *      20(sp) - d0
  22  *      24(sp) - orig_d0
  23  *      28(sp) - stack adjustment
  24  *      2C(sp) - [ sr              ] [ format & vector ]
  25  *      2E(sp) - [ pc-hiword       ] [ sr              ]
  26  *      30(sp) - [ pc-loword       ] [ pc-hiword       ]
  27  *      32(sp) - [ format & vector ] [ pc-loword       ]
  28  *                ^^^^^^^^^^^^^^^^^   ^^^^^^^^^^^^^^^^^
  29  *                      M68K              COLDFIRE
  30  */
  31
  32 #define ALLOWINT 0xf8ff
  33
  34 #ifdef __ASSEMBLY__
  35
  36 /* process bits for task_struct.flags */
  37 PF_TRACESYS_OFF = 3
  38 PF_TRACESYS_BIT = 5
  39 PF_PTRACED_OFF = 3
  40 PF_PTRACED_BIT = 4
  41 PF_DTRACE_OFF = 1
  42 PF_DTRACE_BIT = 5
  43
  44 LENOSYS = 38
  45
  46 #define SWITCH_STACK_SIZE (6*4+4)       /* Includes return address */
  47
  48 /*
  49  * This defines the normal kernel pt-regs layout.
  50  *
  51  * regs are a2-a6 and d6-d7 preserved by C code
  52  * the kernel doesn't mess with usp unless it needs to
  53  */
  54
  55 #ifdef CONFIG_COLDFIRE
  56 /*
  57  * This is made a little more tricky on the ColdFire. There is no
  58  * separate kernel and user stack pointers. Need to artificially
  59  * construct a usp in software... When doing this we need to disable
  60  * interrupts, otherwise bad things could happen.
  61  */
  62 .macro SAVE_ALL
  63         move    #0x2700,%sr             /* disable intrs */
  64         btst    #5,%sp@(2)              /* from user? */
  65         bnes    6f                      /* no, skip */
  66         movel   %sp,sw_usp              /* save user sp */
  67         addql   #8,sw_usp               /* remove exception */
  68         movel   sw_ksp,%sp              /* kernel sp */
  69         subql   #8,%sp                  /* room for exception */
  70         clrl    %sp@-                   /* stkadj */
  71         movel   %d0,%sp@-               /* orig d0 */
  72         movel   %d0,%sp@-               /* d0 */
  73         lea     %sp@(-32),%sp           /* space for 8 regs */
  74         moveml  %d1-%d5/%a0-%a2,%sp@
  75         movel   sw_usp,%a0              /* get usp */
  76         movel   %a0@-,%sp@(PT_PC)       /* copy exception program counter */
  77         movel   %a0@-,%sp@(PT_FORMATVEC)/* copy exception format/vector/sr */
  78         bra     7f
  79         6:
  80         clrl    %sp@-                   /* stkadj */
  81         movel   %d0,%sp@-               /* orig d0 */
  82         movel   %d0,%sp@-               /* d0 */
  83         lea     %sp@(-32),%sp           /* space for 8 regs */
  84         moveml  %d1-%d5/%a0-%a2,%sp@
  85         7:
  86 .endm
  87
  88 .macro RESTORE_ALL
  89         btst    #5,%sp@(PT_SR)          /* going user? */
  90         bnes    8f                      /* no, skip */
  91         move    #0x2700,%sr             /* disable intrs */
  92         movel   sw_usp,%a0              /* get usp */
  93         movel   %sp@(PT_PC),%a0@-       /* copy exception program counter */
  94         movel   %sp@(PT_FORMATVEC),%a0@-/* copy exception format/vector/sr */
  95         moveml  %sp@,%d1-%d5/%a0-%a2
  96         lea     %sp@(32),%sp            /* space for 8 regs */
  97         movel   %sp@+,%d0
  98         addql   #4,%sp                  /* orig d0 */
  99         addl    %sp@+,%sp               /* stkadj */
 100         addql   #8,%sp                  /* remove exception */
 101         movel   %sp,sw_ksp              /* save ksp */
 102         subql   #8,sw_usp               /* set exception */
 103         movel   sw_usp,%sp              /* restore usp */
 104         rte
 105         8:
 106         moveml  %sp@,%d1-%d5/%a0-%a2
 107         lea     %sp@(32),%sp            /* space for 8 regs */
 108         movel   %sp@+,%d0
 109         addql   #4,%sp                  /* orig d0 */
 110         addl    %sp@+,%sp               /* stkadj */
 111         rte
 112 .endm
 113
 114 /*
 115  * Quick exception save, use current stack only.
 116  */
 117 .macro SAVE_LOCAL
 118         move    #0x2700,%sr             /* disable intrs */
 119         clrl    %sp@-                   /* stkadj */
 120         movel   %d0,%sp@-               /* orig d0 */
 121         movel   %d0,%sp@-               /* d0 */
 122         lea     %sp@(-32),%sp           /* space for 8 regs */
 123         moveml  %d1-%d5/%a0-%a2,%sp@
 124 .endm
 125
 126 .macro RESTORE_LOCAL
 127         moveml  %sp@,%d1-%d5/%a0-%a2
 128         lea     %sp@(32),%sp            /* space for 8 regs */
 129         movel   %sp@+,%d0
 130         addql   #4,%sp                  /* orig d0 */
 131         addl    %sp@+,%sp               /* stkadj */
 132         rte
 133 .endm
 134
 135 .macro SAVE_SWITCH_STACK
 136         lea     %sp@(-24),%sp           /* 6 regs */
 137         moveml  %a3-%a6/%d6-%d7,%sp@
 138 .endm
 139
 140 .macro RESTORE_SWITCH_STACK
 141         moveml  %sp@,%a3-%a6/%d6-%d7
 142         lea     %sp@(24),%sp            /* 6 regs */
 143 .endm
 144
 145 /*
 146  * Software copy of the user and kernel stack pointers... Ugh...
 147  * Need these to get around ColdFire not having separate kernel
 148  * and user stack pointers.
 149  */
 150 .globl sw_usp
 151 .globl sw_ksp
 152
 153 #else /* !CONFIG_COLDFIRE */
 154
 155 /*
 156  * Standard 68k interrupt entry and exit macros.
 157  */
 158 .macro SAVE_ALL
 159         clrl    %sp@-                   /* stkadj */
 160         movel   %d0,%sp@-               /* orig d0 */
 161         movel   %d0,%sp@-               /* d0 */
 162         moveml  %d1-%d5/%a0-%a2,%sp@-
 163 .endm
 164
 165 .macro RESTORE_ALL
 166         moveml  %sp@+,%a0-%a2/%d1-%d5
 167         movel   %sp@+,%d0
 168         addql   #4,%sp                  /* orig d0 */
 169         addl    %sp@+,%sp               /* stkadj */
 170         rte
 171 .endm
 172
 173 .macro SAVE_SWITCH_STACK
 174         moveml  %a3-%a6/%d6-%d7,%sp@-
 175 .endm
 176
 177 .macro RESTORE_SWITCH_STACK
 178         moveml  %sp@+,%a3-%a6/%d6-%d7
 179 .endm
 180
 181 #endif /* !CONFIG_COLDFIRE */
 182 #endif /* __ASSEMBLY__ */
 183 #endif /* __M68KNOMMU_ENTRY_H */