arch/mips/math-emu/kernel_linkage.c

   1 /*
   2  *  Kevin D. Kissell, kevink@mips and Carsten Langgaard, carstenl@mips.com
   3  *  Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
   4  *
   5  *  This program is free software; you can distribute it and/or modify it
   6  *  under the terms of the GNU General Public License (Version 2) as
   7  *  published by the Free Software Foundation.
   8  *
   9  *  This program is distributed in the hope it will be useful, but WITHOUT
  10  *  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  *  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  *  for more details.
  13  *
  14  *  You should have received a copy of the GNU General Public License along
  15  *  with this program; if not, write to the Free Software Foundation, Inc.,
  16  *  59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
  17  *
  18  * Routines corresponding to Linux kernel FP context
  19  * manipulation primitives for the Algorithmics MIPS
  20  * FPU Emulator
  21  */
  22 #include <linux/sched.h>
  23 #include <asm/processor.h>
  24 #include <asm/signal.h>
  25 #include <asm/uaccess.h>
  26
  27 #include <asm/fpu_emulator.h>
  28
  29 #define SIGNALLING_NAN 0x7ff800007ff80000LL
  30
  31 void fpu_emulator_init_fpu(void)
  32 {
  33         static int first = 1;
  34         int i;
  35
  36         if (first) {
  37                 first = 0;
  38                 printk("Algorithmics/MIPS FPU Emulator v1.5\n");
  39         }
  40
  41         current->thread.fpu.fcr31 = 0;
  42         for (i = 0; i < 32; i++) {
  43                 current->thread.fpu.fpr[i] = SIGNALLING_NAN;
  44         }
  45 }
  46
  47
  48 /*
  49  * Emulator context save/restore to/from a signal context
  50  * presumed to be on the user stack, and therefore accessed
  51  * with appropriate macros from uaccess.h
  52  */
  53
  54 int fpu_emulator_save_context(struct sigcontext __user *sc)
  55 {
  56         int i;
  57         int err = 0;
  58
  59         for (i = 0; i < 32; i++) {
  60                 err |=
  61                     __put_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
  62         }
  63         err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
  64
  65         return err;
  66 }
  67
  68 int fpu_emulator_restore_context(struct sigcontext __user *sc)
  69 {
  70         int i;
  71         int err = 0;
  72
  73         for (i = 0; i < 32; i++) {
  74                 err |=
  75                     __get_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
  76         }
  77         err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
  78
  79         return err;
  80 }
  81
  82 #ifdef CONFIG_64BIT
  83 /*
  84  * This is the o32 version
  85  */
  86
  87 int fpu_emulator_save_context32(struct sigcontext32 __user *sc)
  88 {
  89         int i;
  90         int err = 0;
  91
  92         for (i = 0; i < 32; i+=2) {
  93                 err |=
  94                     __put_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
  95         }
  96         err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
  97
  98         return err;
  99 }
 100
 101 int fpu_emulator_restore_context32(struct sigcontext32 __user *sc)
 102 {
 103         int i;
 104         int err = 0;
 105
 106         for (i = 0; i < 32; i+=2) {
 107                 err |=
 108                     __get_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
 109         }
 110         err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
 111
 112         return err;
 113 }
 114 #endif