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/config.h>
  23 #include <linux/sched.h>
  24 #include <asm/processor.h>
  25 #include <asm/signal.h>
  26 #include <asm/uaccess.h>
  27
  28 #include <asm/fpu_emulator.h>
  29
  30 extern struct mips_fpu_emulator_private fpuemuprivate;
  31
  32 #define SIGNALLING_NAN 0x7ff800007ff80000LL
  33
  34 void fpu_emulator_init_fpu(void)
  35 {
  36         static int first = 1;
  37         int i;
  38
  39         if (first) {
  40                 first = 0;
  41                 printk("Algorithmics/MIPS FPU Emulator v1.5\n");
  42         }
  43
  44         current->thread.fpu.soft.fcr31 = 0;
  45         for (i = 0; i < 32; i++) {
  46                 current->thread.fpu.soft.fpr[i] = SIGNALLING_NAN;
  47         }
  48 }
  49
  50
  51 /*
  52  * Emulator context save/restore to/from a signal context
  53  * presumed to be on the user stack, and therefore accessed
  54  * with appropriate macros from uaccess.h
  55  */
  56
  57 int fpu_emulator_save_context(struct sigcontext *sc)
  58 {
  59         int i;
  60         int err = 0;
  61
  62         for (i = 0; i < 32; i++) {
  63                 err |=
  64                     __put_user(current->thread.fpu.soft.fpr[i],
  65                                &sc->sc_fpregs[i]);
  66         }
  67         err |= __put_user(current->thread.fpu.soft.fcr31, &sc->sc_fpc_csr);
  68         err |= __put_user(fpuemuprivate.eir, &sc->sc_fpc_eir);
  69
  70         return err;
  71 }
  72
  73 int fpu_emulator_restore_context(struct sigcontext *sc)
  74 {
  75         int i;
  76         int err = 0;
  77
  78         for (i = 0; i < 32; i++) {
  79                 err |=
  80                     __get_user(current->thread.fpu.soft.fpr[i],
  81                                &sc->sc_fpregs[i]);
  82         }
  83         err |= __get_user(current->thread.fpu.soft.fcr31, &sc->sc_fpc_csr);
  84         err |= __get_user(fpuemuprivate.eir, &sc->sc_fpc_eir);
  85
  86         return err;
  87 }
  88
  89 #ifdef CONFIG_MIPS64
  90 /*
  91  * This is the o32 version
  92  */
  93
  94 int fpu_emulator_save_context32(struct sigcontext32 *sc)
  95 {
  96         int i;
  97         int err = 0;
  98
  99         for (i = 0; i < 32; i+=2) {
 100                 err |=
 101                     __put_user(current->thread.fpu.soft.fpr[i],
 102                                &sc->sc_fpregs[i]);
 103         }
 104         err |= __put_user(current->thread.fpu.soft.fcr31, &sc->sc_fpc_csr);
 105         err |= __put_user(fpuemuprivate.eir, &sc->sc_fpc_eir);
 106
 107         return err;
 108 }
 109
 110 int fpu_emulator_restore_context32(struct sigcontext32 *sc)
 111 {
 112         int i;
 113         int err = 0;
 114
 115         for (i = 0; i < 32; i+=2) {
 116                 err |=
 117                     __get_user(current->thread.fpu.soft.fpr[i],
 118                                &sc->sc_fpregs[i]);
 119         }
 120         err |= __get_user(current->thread.fpu.soft.fcr31, &sc->sc_fpc_csr);
 121         err |= __get_user(fpuemuprivate.eir, &sc->sc_fpc_eir);
 122
 123         return err;
 124 }
 125 #endif