xref: /linux/arch/arm/nwfpe/fpa11.h (revision 58e16d792a6a8c6b750f637a4649967fcac853dc)
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 
28 struct 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  */
44 typedef 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  */
67 typedef 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 
81 extern int8 SetRoundingMode(const unsigned int);
82 extern int8 SetRoundingPrecision(const unsigned int);
83 extern void nwfpe_init_fpa(union fp_state *fp);
84 
85 extern unsigned int EmulateAll(unsigned int opcode);
86 
87 extern unsigned int EmulateCPDT(const unsigned int opcode);
88 extern unsigned int EmulateCPDO(const unsigned int opcode);
89 extern unsigned int EmulateCPRT(const unsigned int opcode);
90 
91 /* fpa11_cpdt.c */
92 extern unsigned int PerformLDF(const unsigned int opcode);
93 extern unsigned int PerformSTF(const unsigned int opcode);
94 extern unsigned int PerformLFM(const unsigned int opcode);
95 extern unsigned int PerformSFM(const unsigned int opcode);
96 
97 /* single_cpdo.c */
98 
99 extern unsigned int SingleCPDO(struct roundingData *roundData,
100 			       const unsigned int opcode, FPREG * rFd);
101 /* double_cpdo.c */
102 extern unsigned int DoubleCPDO(struct roundingData *roundData,
103 			       const unsigned int opcode, FPREG * rFd);
104 
105 /* extneded_cpdo.c */
106 extern unsigned int ExtendedCPDO(struct roundingData *roundData,
107 				 const unsigned int opcode, FPREG * rFd);
108 
109 #endif
110