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
  40 struct 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  */
  56 typedef 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  */
  79 typedef 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
  93 extern int8 SetRoundingMode(const unsigned int);
  94 extern int8 SetRoundingPrecision(const unsigned int);
  95 extern void nwfpe_init_fpa(union fp_state *fp);
  96
  97 extern unsigned int EmulateAll(unsigned int opcode);
  98
  99 extern unsigned int EmulateCPDT(const unsigned int opcode);
 100 extern unsigned int EmulateCPDO(const unsigned int opcode);
 101 extern unsigned int EmulateCPRT(const unsigned int opcode);
 102
 103 /* fpa11_cpdt.c */
 104 extern unsigned int PerformLDF(const unsigned int opcode);
 105 extern unsigned int PerformSTF(const unsigned int opcode);
 106 extern unsigned int PerformLFM(const unsigned int opcode);
 107 extern unsigned int PerformSFM(const unsigned int opcode);
 108
 109 /* single_cpdo.c */
 110
 111 extern unsigned int SingleCPDO(struct roundingData *roundData,
 112                                const unsigned int opcode, FPREG * rFd);
 113 /* double_cpdo.c */
 114 extern unsigned int DoubleCPDO(struct roundingData *roundData,
 115                                const unsigned int opcode, FPREG * rFd);
 116
 117 #endif