LXR linux/arch/mips/math-emu/kernel

   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.h>
  28#include <asm/fpu_emulator.h>
  29
  30#define SIGNALLING_NAN 0x7ff800007ff80000LL
  31
  32void fpu_emulator_init_fpu(void)
  33{
  34        static int first = 1;
  35        int i;
  36
  37        if (first) {
  38                first = 0;
  39                printk("Algorithmics/MIPS FPU Emulator v1.5\n");
  40        }
  41
  42        current->thread.fpu.fcr31 = 0;
  43        for (i = 0; i < 32; i++) {
  44                current->thread.fpu.fpr[i] = SIGNALLING_NAN;
  45        }
  46}
  47
  48
  49/*
  50 * Emulator context save/restore to/from a signal context
  51 * presumed to be on the user stack, and therefore accessed
  52 * with appropriate macros from uaccess.h
  53 */
  54
  55int fpu_emulator_save_context(struct sigcontext __user *sc)
  56{
  57        int i;
  58        int err = 0;
  59
  60        for (i = 0; i < 32; i++) {
  61                err |=
  62                    __put_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
  63        }
  64        err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
  65
  66        return err;
  67}
  68
  69int fpu_emulator_restore_context(struct sigcontext __user *sc)
  70{
  71        int i;
  72        int err = 0;
  73
  74        for (i = 0; i < 32; i++) {
  75                err |=
  76                    __get_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
  77        }
  78        err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
  79
  80        return err;
  81}
  82
  83#ifdef CONFIG_64BIT
  84/*
  85 * This is the o32 version
  86 */
  87
  88int fpu_emulator_save_context32(struct sigcontext32 __user *sc)
  89{
  90        int i;
  91        int err = 0;
  92
  93        for (i = 0; i < 32; i+=2) {
  94                err |=
  95                    __put_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
  96        }
  97        err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
  98
  99        return err;
 100}
 101
 102int fpu_emulator_restore_context32(struct sigcontext32 __user *sc)
 103{
 104        int i;
 105        int err = 0;
 106
 107        for (i = 0; i < 32; i+=2) {
 108                err |=
 109                    __get_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
 110        }
 111        err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
 112
 113        return err;
 114}
 115#endif
 116