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