LXR linux/arch/arm/nwfpe/fpa11.h

   1/*
   2    NetWinder Floating Point Emulator
   3    (c) Rebel.com, 1998-1999
   4    
   5    Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20*/
  21
  22#ifndef __FPA11_H__
  23#define __FPA11_H__
  24
  25#define GET_FPA11() ((FPA11 *)(&current_thread_info()->fpstate))
  26
  27/*
  28 * The processes registers are always at the very top of the 8K
  29 * stack+task struct.  Use the same method as 'current' uses to
  30 * reach them.
  31 */
  32#define GET_USERREG() ((struct pt_regs *)(THREAD_START_SP + (unsigned long)current_thread_info()) - 1)
  33
  34#include <linux/thread_info.h>
  35
  36/* includes */
  37#include "fpsr.h"               /* FP control and status register definitions */
  38#include "milieu.h"
  39
  40struct roundingData {
  41    int8 mode;
  42    int8 precision;
  43    signed char exception;
  44};
  45
  46#include "softfloat.h"
  47
  48#define         typeNone                0x00
  49#define         typeSingle              0x01
  50#define         typeDouble              0x02
  51#define         typeExtended            0x03
  52
  53/*
  54 * This must be no more and no less than 12 bytes.
  55 */
  56typedef union tagFPREG {
  57        float32 fSingle;
  58        float64 fDouble;
  59#ifdef CONFIG_FPE_NWFPE_XP
  60        floatx80 fExtended;
  61#else
  62        u32 padding[3];
  63#endif
  64} __attribute__ ((packed,aligned(4))) FPREG;
  65
  66/*
  67 * FPA11 device model.
  68 *
  69 * This structure is exported to user space.  Do not re-order.
  70 * Only add new stuff to the end, and do not change the size of
  71 * any element.  Elements of this structure are used by user
  72 * space, and must match struct user_fp in <asm/user.h>.
  73 * We include the byte offsets below for documentation purposes.
  74 *
  75 * The size of this structure and FPREG are checked by fpmodule.c
  76 * on initialisation.  If the rules have been broken, NWFPE will
  77 * not initialise.
  78 */
  79typedef struct tagFPA11 {
  80/*   0 */ FPREG fpreg[8];       /* 8 floating point registers */
  81/*  96 */ FPSR fpsr;            /* floating point status register */
  82/* 100 */ FPCR fpcr;            /* floating point control register */
  83/* 104 */ unsigned char fType[8];       /* type of floating point value held in
  84                                           floating point registers.  One of
  85                                           none, single, double or extended. */
  86/* 112 */ int initflag;         /* this is special.  The kernel guarantees
  87                                   to set it to 0 when a thread is launched,
  88                                   so we can use it to detect whether this
  89                                   instance of the emulator needs to be
  90                                   initialised. */
  91} __attribute__ ((packed,aligned(4))) FPA11;
  92
  93extern int8 SetRoundingMode(const unsigned int);
  94extern int8 SetRoundingPrecision(const unsigned int);
  95extern void nwfpe_init_fpa(union fp_state *fp);
  96
  97extern unsigned int EmulateAll(unsigned int opcode);
  98
  99extern unsigned int EmulateCPDT(const unsigned int opcode);
 100extern unsigned int EmulateCPDO(const unsigned int opcode);
 101extern unsigned int EmulateCPRT(const unsigned int opcode);
 102
 103/* fpa11_cpdt.c */
 104extern unsigned int PerformLDF(const unsigned int opcode);
 105extern unsigned int PerformSTF(const unsigned int opcode);
 106extern unsigned int PerformLFM(const unsigned int opcode);
 107extern unsigned int PerformSFM(const unsigned int opcode);
 108
 109/* single_cpdo.c */
 110
 111extern unsigned int SingleCPDO(struct roundingData *roundData,
 112                               const unsigned int opcode, FPREG * rFd);
 113/* double_cpdo.c */
 114extern unsigned int DoubleCPDO(struct roundingData *roundData,
 115                               const unsigned int opcode, FPREG * rFd);
 116
 117/* extneded_cpdo.c */
 118extern unsigned int ExtendedCPDO(struct roundingData *roundData,
 119                                 const unsigned int opcode, FPREG * rFd);
 120
 121#endif
 122