root/arch/mips/kvm/fpu.S

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * FPU context handling code for KVM.
   7  *
   8  * Copyright (C) 2015 Imagination Technologies Ltd.
   9  */
  10 
  11 #include <asm/asm.h>
  12 #include <asm/asm-offsets.h>
  13 #include <asm/fpregdef.h>
  14 #include <asm/mipsregs.h>
  15 #include <asm/regdef.h>
  16 
  17 /* preprocessor replaces the fp in ".set fp=64" with $30 otherwise */
  18 #undef fp
  19 
  20         .set    noreorder
  21         .set    noat
  22 
  23 LEAF(__kvm_save_fpu)
  24         .set    push
  25         SET_HARDFLOAT
  26         .set    fp=64
  27         mfc0    t0, CP0_STATUS
  28         sll     t0, t0, 5                       # is Status.FR set?
  29         bgez    t0, 1f                          # no: skip odd doubles
  30          nop
  31         sdc1    $f1,  VCPU_FPR1(a0)
  32         sdc1    $f3,  VCPU_FPR3(a0)
  33         sdc1    $f5,  VCPU_FPR5(a0)
  34         sdc1    $f7,  VCPU_FPR7(a0)
  35         sdc1    $f9,  VCPU_FPR9(a0)
  36         sdc1    $f11, VCPU_FPR11(a0)
  37         sdc1    $f13, VCPU_FPR13(a0)
  38         sdc1    $f15, VCPU_FPR15(a0)
  39         sdc1    $f17, VCPU_FPR17(a0)
  40         sdc1    $f19, VCPU_FPR19(a0)
  41         sdc1    $f21, VCPU_FPR21(a0)
  42         sdc1    $f23, VCPU_FPR23(a0)
  43         sdc1    $f25, VCPU_FPR25(a0)
  44         sdc1    $f27, VCPU_FPR27(a0)
  45         sdc1    $f29, VCPU_FPR29(a0)
  46         sdc1    $f31, VCPU_FPR31(a0)
  47 1:      sdc1    $f0,  VCPU_FPR0(a0)
  48         sdc1    $f2,  VCPU_FPR2(a0)
  49         sdc1    $f4,  VCPU_FPR4(a0)
  50         sdc1    $f6,  VCPU_FPR6(a0)
  51         sdc1    $f8,  VCPU_FPR8(a0)
  52         sdc1    $f10, VCPU_FPR10(a0)
  53         sdc1    $f12, VCPU_FPR12(a0)
  54         sdc1    $f14, VCPU_FPR14(a0)
  55         sdc1    $f16, VCPU_FPR16(a0)
  56         sdc1    $f18, VCPU_FPR18(a0)
  57         sdc1    $f20, VCPU_FPR20(a0)
  58         sdc1    $f22, VCPU_FPR22(a0)
  59         sdc1    $f24, VCPU_FPR24(a0)
  60         sdc1    $f26, VCPU_FPR26(a0)
  61         sdc1    $f28, VCPU_FPR28(a0)
  62         jr      ra
  63          sdc1   $f30, VCPU_FPR30(a0)
  64         .set    pop
  65         END(__kvm_save_fpu)
  66 
  67 LEAF(__kvm_restore_fpu)
  68         .set    push
  69         SET_HARDFLOAT
  70         .set    fp=64
  71         mfc0    t0, CP0_STATUS
  72         sll     t0, t0, 5                       # is Status.FR set?
  73         bgez    t0, 1f                          # no: skip odd doubles
  74          nop
  75         ldc1    $f1,  VCPU_FPR1(a0)
  76         ldc1    $f3,  VCPU_FPR3(a0)
  77         ldc1    $f5,  VCPU_FPR5(a0)
  78         ldc1    $f7,  VCPU_FPR7(a0)
  79         ldc1    $f9,  VCPU_FPR9(a0)
  80         ldc1    $f11, VCPU_FPR11(a0)
  81         ldc1    $f13, VCPU_FPR13(a0)
  82         ldc1    $f15, VCPU_FPR15(a0)
  83         ldc1    $f17, VCPU_FPR17(a0)
  84         ldc1    $f19, VCPU_FPR19(a0)
  85         ldc1    $f21, VCPU_FPR21(a0)
  86         ldc1    $f23, VCPU_FPR23(a0)
  87         ldc1    $f25, VCPU_FPR25(a0)
  88         ldc1    $f27, VCPU_FPR27(a0)
  89         ldc1    $f29, VCPU_FPR29(a0)
  90         ldc1    $f31, VCPU_FPR31(a0)
  91 1:      ldc1    $f0,  VCPU_FPR0(a0)
  92         ldc1    $f2,  VCPU_FPR2(a0)
  93         ldc1    $f4,  VCPU_FPR4(a0)
  94         ldc1    $f6,  VCPU_FPR6(a0)
  95         ldc1    $f8,  VCPU_FPR8(a0)
  96         ldc1    $f10, VCPU_FPR10(a0)
  97         ldc1    $f12, VCPU_FPR12(a0)
  98         ldc1    $f14, VCPU_FPR14(a0)
  99         ldc1    $f16, VCPU_FPR16(a0)
 100         ldc1    $f18, VCPU_FPR18(a0)
 101         ldc1    $f20, VCPU_FPR20(a0)
 102         ldc1    $f22, VCPU_FPR22(a0)
 103         ldc1    $f24, VCPU_FPR24(a0)
 104         ldc1    $f26, VCPU_FPR26(a0)
 105         ldc1    $f28, VCPU_FPR28(a0)
 106         jr      ra
 107          ldc1   $f30, VCPU_FPR30(a0)
 108         .set    pop
 109         END(__kvm_restore_fpu)
 110 
 111 LEAF(__kvm_restore_fcsr)
 112         .set    push
 113         SET_HARDFLOAT
 114         lw      t0, VCPU_FCR31(a0)
 115         /*
 116          * The ctc1 must stay at this offset in __kvm_restore_fcsr.
 117          * See kvm_mips_csr_die_notify() which handles t0 containing a value
 118          * which triggers an FP Exception, which must be stepped over and
 119          * ignored since the set cause bits must remain there for the guest.
 120          */
 121         ctc1    t0, fcr31
 122         jr      ra
 123          nop
 124         .set    pop
 125         END(__kvm_restore_fcsr)