arch/mn10300/kernel/fpu-low.S

   1 /* MN10300 Low level FPU management operations
   2  *
   3  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  */
  11 #include <linux/linkage.h>
  12 #include <asm/cpu-regs.h>
  13 #include <asm/smp.h>
  14 #include <asm/thread_info.h>
  15 #include <asm/asm-offsets.h>
  16 #include <asm/frame.inc>
  17
  18 .macro FPU_INIT_STATE_ALL
  19         fmov    0,fs0
  20         fmov    fs0,fs1
  21         fmov    fs0,fs2
  22         fmov    fs0,fs3
  23         fmov    fs0,fs4
  24         fmov    fs0,fs5
  25         fmov    fs0,fs6
  26         fmov    fs0,fs7
  27         fmov    fs0,fs8
  28         fmov    fs0,fs9
  29         fmov    fs0,fs10
  30         fmov    fs0,fs11
  31         fmov    fs0,fs12
  32         fmov    fs0,fs13
  33         fmov    fs0,fs14
  34         fmov    fs0,fs15
  35         fmov    fs0,fs16
  36         fmov    fs0,fs17
  37         fmov    fs0,fs18
  38         fmov    fs0,fs19
  39         fmov    fs0,fs20
  40         fmov    fs0,fs21
  41         fmov    fs0,fs22
  42         fmov    fs0,fs23
  43         fmov    fs0,fs24
  44         fmov    fs0,fs25
  45         fmov    fs0,fs26
  46         fmov    fs0,fs27
  47         fmov    fs0,fs28
  48         fmov    fs0,fs29
  49         fmov    fs0,fs30
  50         fmov    fs0,fs31
  51         fmov    FPCR_INIT,fpcr
  52 .endm
  53
  54 .macro FPU_SAVE_ALL areg,dreg
  55         fmov    fs0,(\areg+)
  56         fmov    fs1,(\areg+)
  57         fmov    fs2,(\areg+)
  58         fmov    fs3,(\areg+)
  59         fmov    fs4,(\areg+)
  60         fmov    fs5,(\areg+)
  61         fmov    fs6,(\areg+)
  62         fmov    fs7,(\areg+)
  63         fmov    fs8,(\areg+)
  64         fmov    fs9,(\areg+)
  65         fmov    fs10,(\areg+)
  66         fmov    fs11,(\areg+)
  67         fmov    fs12,(\areg+)
  68         fmov    fs13,(\areg+)
  69         fmov    fs14,(\areg+)
  70         fmov    fs15,(\areg+)
  71         fmov    fs16,(\areg+)
  72         fmov    fs17,(\areg+)
  73         fmov    fs18,(\areg+)
  74         fmov    fs19,(\areg+)
  75         fmov    fs20,(\areg+)
  76         fmov    fs21,(\areg+)
  77         fmov    fs22,(\areg+)
  78         fmov    fs23,(\areg+)
  79         fmov    fs24,(\areg+)
  80         fmov    fs25,(\areg+)
  81         fmov    fs26,(\areg+)
  82         fmov    fs27,(\areg+)
  83         fmov    fs28,(\areg+)
  84         fmov    fs29,(\areg+)
  85         fmov    fs30,(\areg+)
  86         fmov    fs31,(\areg+)
  87         fmov    fpcr,\dreg
  88         mov     \dreg,(\areg)
  89 .endm
  90
  91 .macro FPU_RESTORE_ALL areg,dreg
  92         fmov    (\areg+),fs0
  93         fmov    (\areg+),fs1
  94         fmov    (\areg+),fs2
  95         fmov    (\areg+),fs3
  96         fmov    (\areg+),fs4
  97         fmov    (\areg+),fs5
  98         fmov    (\areg+),fs6
  99         fmov    (\areg+),fs7
 100         fmov    (\areg+),fs8
 101         fmov    (\areg+),fs9
 102         fmov    (\areg+),fs10
 103         fmov    (\areg+),fs11
 104         fmov    (\areg+),fs12
 105         fmov    (\areg+),fs13
 106         fmov    (\areg+),fs14
 107         fmov    (\areg+),fs15
 108         fmov    (\areg+),fs16
 109         fmov    (\areg+),fs17
 110         fmov    (\areg+),fs18
 111         fmov    (\areg+),fs19
 112         fmov    (\areg+),fs20
 113         fmov    (\areg+),fs21
 114         fmov    (\areg+),fs22
 115         fmov    (\areg+),fs23
 116         fmov    (\areg+),fs24
 117         fmov    (\areg+),fs25
 118         fmov    (\areg+),fs26
 119         fmov    (\areg+),fs27
 120         fmov    (\areg+),fs28
 121         fmov    (\areg+),fs29
 122         fmov    (\areg+),fs30
 123         fmov    (\areg+),fs31
 124         mov     (\areg),\dreg
 125         fmov    \dreg,fpcr
 126 .endm
 127
 128 ###############################################################################
 129 #
 130 # void fpu_init_state(void)
 131 # - initialise the FPU
 132 #
 133 ###############################################################################
 134         .globl  fpu_init_state
 135         .type   fpu_init_state,@function
 136 fpu_init_state:
 137         mov     epsw,d0
 138         or      EPSW_FE,epsw
 139
 140 #ifdef CONFIG_MN10300_PROC_MN103E010
 141         nop
 142         nop
 143         nop
 144 #endif
 145         FPU_INIT_STATE_ALL
 146 #ifdef CONFIG_MN10300_PROC_MN103E010
 147         nop
 148         nop
 149         nop
 150 #endif
 151         mov     d0,epsw
 152         ret     [],0
 153
 154         .size   fpu_init_state,.-fpu_init_state
 155
 156 ###############################################################################
 157 #
 158 # void fpu_save(struct fpu_state_struct *)
 159 # - save the fpu state
 160 # - note that an FPU Operational exception might occur during this process
 161 #
 162 ###############################################################################
 163         .globl  fpu_save
 164         .type   fpu_save,@function
 165 fpu_save:
 166         mov     epsw,d1
 167         or      EPSW_FE,epsw            /* enable the FPU so we can access it */
 168
 169 #ifdef CONFIG_MN10300_PROC_MN103E010
 170         nop
 171         nop
 172 #endif
 173         mov     d0,a0
 174         FPU_SAVE_ALL    a0,d0
 175 #ifdef CONFIG_MN10300_PROC_MN103E010
 176         nop
 177         nop
 178 #endif
 179
 180         mov     d1,epsw
 181         ret     [],0
 182
 183         .size   fpu_save,.-fpu_save
 184
 185 ###############################################################################
 186 #
 187 # void fpu_disabled(void)
 188 # - handle an exception due to the FPU being disabled
 189 #   when CONFIG_FPU is enabled
 190 #
 191 ###############################################################################
 192         .type   fpu_disabled,@function
 193         .globl  fpu_disabled
 194 fpu_disabled:
 195         or      EPSW_nAR|EPSW_FE,epsw
 196         nop
 197         nop
 198         nop
 199
 200         mov     sp,a1
 201         mov     (a1),d1                 /* get epsw of user context */
 202         and     ~(THREAD_SIZE-1),a1     /* a1: (thread_info *ti) */
 203         mov     (TI_task,a1),a2         /* a2: (task_struct *tsk) */
 204         btst    EPSW_nSL,d1
 205         beq     fpu_used_in_kernel
 206
 207         or      EPSW_FE,d1
 208         mov     d1,(sp)
 209         mov     (TASK_THREAD+THREAD_FPU_FLAGS,a2),d1
 210 #ifndef CONFIG_LAZY_SAVE_FPU
 211         or      __THREAD_HAS_FPU,d1
 212         mov     d1,(TASK_THREAD+THREAD_FPU_FLAGS,a2)
 213 #else  /* !CONFIG_LAZY_SAVE_FPU */
 214         mov     (fpu_state_owner),a0
 215         cmp     0,a0
 216         beq     fpu_regs_save_end
 217
 218         mov     (TASK_THREAD+THREAD_UREGS,a0),a1
 219         add     TASK_THREAD+THREAD_FPU_STATE,a0
 220         FPU_SAVE_ALL a0,d0
 221
 222         mov     (REG_EPSW,a1),d0
 223         and     ~EPSW_FE,d0
 224         mov     d0,(REG_EPSW,a1)
 225
 226 fpu_regs_save_end:
 227         mov     a2,(fpu_state_owner)
 228 #endif /* !CONFIG_LAZY_SAVE_FPU */
 229
 230         btst    __THREAD_USING_FPU,d1
 231         beq     fpu_regs_init
 232         add     TASK_THREAD+THREAD_FPU_STATE,a2
 233         FPU_RESTORE_ALL a2,d0
 234         rti
 235
 236 fpu_regs_init:
 237         FPU_INIT_STATE_ALL
 238         add     TASK_THREAD+THREAD_FPU_FLAGS,a2
 239         bset    __THREAD_USING_FPU,(0,a2)
 240         rti
 241
 242 fpu_used_in_kernel:
 243         and     ~(EPSW_nAR|EPSW_FE),epsw
 244         nop
 245         nop
 246
 247         add     -4,sp
 248         SAVE_ALL
 249         mov     -1,d0
 250         mov     d0,(REG_ORIG_D0,fp)
 251
 252         and     ~EPSW_NMID,epsw
 253
 254         mov     fp,d0
 255         call    fpu_disabled_in_kernel[],0
 256         jmp     ret_from_exception
 257
 258         .size   fpu_disabled,.-fpu_disabled