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 *)(¤t_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 /* extneded_cpdo.c */ 118 extern unsigned int ExtendedCPDO(struct roundingData *roundData, 119 const unsigned int opcode, FPREG * rFd); 120 121 #endif 122