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.h>
  28 #include <asm/fpu_emulator.h>
  29
  30 #define SIGNALLING_NAN 0x7ff800007ff80000LL
  31
  32 void 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
  55 int 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
  69 int 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
  88 int fpu_emulator_save_context32(struct sigcontext32 __user *sc)
  89 {
  90         int i;
  91         int err = 0;
  92         int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
  93
  94         for (i = 0; i < 32; i += inc) {
  95                 err |=
  96                     __put_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
  97         }
  98         err |= __put_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
  99
 100         return err;
 101 }
 102
 103 int fpu_emulator_restore_context32(struct sigcontext32 __user *sc)
 104 {
 105         int i;
 106         int err = 0;
 107         int inc = test_thread_flag(TIF_32BIT_FPREGS) ? 2 : 1;
 108
 109         for (i = 0; i < 32; i += inc) {
 110                 err |=
 111                     __get_user(current->thread.fpu.fpr[i], &sc->sc_fpregs[i]);
 112         }
 113         err |= __get_user(current->thread.fpu.fcr31, &sc->sc_fpc_csr);
 114
 115         return err;
 116 }
 117 #endif