arch/mips/kernel/r6000_fpu.S

   1 /*
   2  * r6000_fpu.S: Save/restore floating point context for signal handlers.
   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) 1996 by Ralf Baechle
   9  *
  10  * Multi-arch abstraction and asm macros for easier reading:
  11  * Copyright (C) 1996 David S. Miller (dm@engr.sgi.com)
  12  */
  13 #include <asm/asm.h>
  14 #include <asm/fpregdef.h>
  15 #include <asm/mipsregs.h>
  16 #include <asm/asm-offsets.h>
  17 #include <asm/regdef.h>
  18
  19         .set    noreorder
  20         .set    mips2
  21         /* Save floating point context */
  22         LEAF(_save_fp_context)
  23         mfc0    t0,CP0_STATUS
  24         sll     t0,t0,2
  25         bgez    t0,1f
  26          nop
  27
  28         cfc1    t1,fcr31
  29         /* Store the 16 double precision registers */
  30         sdc1    $f0,(SC_FPREGS+0)(a0)
  31         sdc1    $f2,(SC_FPREGS+16)(a0)
  32         sdc1    $f4,(SC_FPREGS+32)(a0)
  33         sdc1    $f6,(SC_FPREGS+48)(a0)
  34         sdc1    $f8,(SC_FPREGS+64)(a0)
  35         sdc1    $f10,(SC_FPREGS+80)(a0)
  36         sdc1    $f12,(SC_FPREGS+96)(a0)
  37         sdc1    $f14,(SC_FPREGS+112)(a0)
  38         sdc1    $f16,(SC_FPREGS+128)(a0)
  39         sdc1    $f18,(SC_FPREGS+144)(a0)
  40         sdc1    $f20,(SC_FPREGS+160)(a0)
  41         sdc1    $f22,(SC_FPREGS+176)(a0)
  42         sdc1    $f24,(SC_FPREGS+192)(a0)
  43         sdc1    $f26,(SC_FPREGS+208)(a0)
  44         sdc1    $f28,(SC_FPREGS+224)(a0)
  45         sdc1    $f30,(SC_FPREGS+240)(a0)
  46         jr      ra
  47          sw     t0,SC_FPC_CSR(a0)
  48 1:      jr      ra
  49          nop
  50         END(_save_fp_context)
  51
  52 /* Restore FPU state:
  53  *  - fp gp registers
  54  *  - cp1 status/control register
  55  *
  56  * We base the decision which registers to restore from the signal stack
  57  * frame on the current content of c0_status, not on the content of the
  58  * stack frame which might have been changed by the user.
  59  */
  60         LEAF(_restore_fp_context)
  61         mfc0    t0,CP0_STATUS
  62         sll     t0,t0,2
  63
  64         bgez    t0,1f
  65          lw     t0,SC_FPC_CSR(a0)
  66         /* Restore the 16 double precision registers */
  67         ldc1    $f0,(SC_FPREGS+0)(a0)
  68         ldc1    $f2,(SC_FPREGS+16)(a0)
  69         ldc1    $f4,(SC_FPREGS+32)(a0)
  70         ldc1    $f6,(SC_FPREGS+48)(a0)
  71         ldc1    $f8,(SC_FPREGS+64)(a0)
  72         ldc1    $f10,(SC_FPREGS+80)(a0)
  73         ldc1    $f12,(SC_FPREGS+96)(a0)
  74         ldc1    $f14,(SC_FPREGS+112)(a0)
  75         ldc1    $f16,(SC_FPREGS+128)(a0)
  76         ldc1    $f18,(SC_FPREGS+144)(a0)
  77         ldc1    $f20,(SC_FPREGS+160)(a0)
  78         ldc1    $f22,(SC_FPREGS+176)(a0)
  79         ldc1    $f24,(SC_FPREGS+192)(a0)
  80         ldc1    $f26,(SC_FPREGS+208)(a0)
  81         ldc1    $f28,(SC_FPREGS+224)(a0)
  82         ldc1    $f30,(SC_FPREGS+240)(a0)
  83         jr      ra
  84          ctc1   t0,fcr31
  85 1:      jr      ra
  86          nop
  87         END(_restore_fp_context)