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

   1/* SPDX-License-Identifier: GPL-2.0-or-later */
   2/*
   3    NetWinder Floating Point Emulator
   4    (c) Rebel.com, 1998-1999
   5    
   6    Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
   7
   8*/
   9
  10#ifndef __FPA11_H__
  11#define __FPA11_H__
  12
  13#define GET_FPA11() ((FPA11 *)(&current_thread_info()->fpstate))
  14
  15/*
  16 * The processes registers are always at the very top of the 8K
  17 * stack+task struct.  Use the same method as 'current' uses to
  18 * reach them.
  19 */
  20#define GET_USERREG() ((struct pt_regs *)(THREAD_START_SP + (unsigned long)current_thread_info()) - 1)
  21
  22#include <linux/thread_info.h>
  23
  24/* includes */
  25#include "fpsr.h"               /* FP control and status register definitions */
  26#include "milieu.h"
  27
  28struct roundingData {
  29    int8 mode;
  30    int8 precision;
  31    signed char exception;
  32};
  33
  34#include "softfloat.h"
  35
  36#define         typeNone                0x00
  37#define         typeSingle              0x01
  38#define         typeDouble              0x02
  39#define         typeExtended            0x03
  40
  41/*
  42 * This must be no more and no less than 12 bytes.
  43 */
  44typedef union tagFPREG {
  45        float32 fSingle;
  46        float64 fDouble;
  47#ifdef CONFIG_FPE_NWFPE_XP
  48        floatx80 fExtended;
  49#else
  50        u32 padding[3];
  51#endif
  52} __attribute__ ((packed,aligned(4))) FPREG;
  53
  54/*
  55 * FPA11 device model.
  56 *
  57 * This structure is exported to user space.  Do not re-order.
  58 * Only add new stuff to the end, and do not change the size of
  59 * any element.  Elements of this structure are used by user
  60 * space, and must match struct user_fp in <asm/user.h>.
  61 * We include the byte offsets below for documentation purposes.
  62 *
  63 * The size of this structure and FPREG are checked by fpmodule.c
  64 * on initialisation.  If the rules have been broken, NWFPE will
  65 * not initialise.
  66 */
  67typedef struct tagFPA11 {
  68/*   0 */ FPREG fpreg[8];       /* 8 floating point registers */
  69/*  96 */ FPSR fpsr;            /* floating point status register */
  70/* 100 */ FPCR fpcr;            /* floating point control register */
  71/* 104 */ unsigned char fType[8];       /* type of floating point value held in
  72                                           floating point registers.  One of
  73                                           none, single, double or extended. */
  74/* 112 */ int initflag;         /* this is special.  The kernel guarantees
  75                                   to set it to 0 when a thread is launched,
  76                                   so we can use it to detect whether this
  77                                   instance of the emulator needs to be
  78                                   initialised. */
  79} __attribute__ ((packed,aligned(4))) FPA11;
  80
  81extern int8 SetRoundingMode(const unsigned int);
  82extern int8 SetRoundingPrecision(const unsigned int);
  83extern void nwfpe_init_fpa(union fp_state *fp);
  84
  85extern unsigned int EmulateAll(unsigned int opcode);
  86
  87extern unsigned int EmulateCPDT(const unsigned int opcode);
  88extern unsigned int EmulateCPDO(const unsigned int opcode);
  89extern unsigned int EmulateCPRT(const unsigned int opcode);
  90
  91/* fpa11_cpdt.c */
  92extern unsigned int PerformLDF(const unsigned int opcode);
  93extern unsigned int PerformSTF(const unsigned int opcode);
  94extern unsigned int PerformLFM(const unsigned int opcode);
  95extern unsigned int PerformSFM(const unsigned int opcode);
  96
  97/* single_cpdo.c */
  98
  99extern unsigned int SingleCPDO(struct roundingData *roundData,
 100                               const unsigned int opcode, FPREG * rFd);
 101/* double_cpdo.c */
 102extern unsigned int DoubleCPDO(struct roundingData *roundData,
 103                               const unsigned int opcode, FPREG * rFd);
 104
 105/* extneded_cpdo.c */
 106extern unsigned int ExtendedCPDO(struct roundingData *roundData,
 107                                 const unsigned int opcode, FPREG * rFd);
 108
 109#endif
 110