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 *)(¤t_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