xref: /freebsd/sys/amd64/include/fpu.h (revision 9ccc37e32070303fb293a2a1697ffa71eeb49b25)
1 /*-
2  * Copyright (c) 1990 The Regents of the University of California.
3  * All rights reserved.
4  *
5  * This code is derived from software contributed to Berkeley by
6  * William Jolitz.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 4. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  *	from: @(#)npx.h	5.3 (Berkeley) 1/18/91
33  * $FreeBSD$
34  */
35 
36 /*
37  * Floating Point Data Structures and Constants
38  * W. Jolitz 1/90
39  */
40 
41 #ifndef _MACHINE_FPU_H_
42 #define	_MACHINE_FPU_H_
43 
44 /* Contents of each x87 floating point accumulator */
45 struct fpacc87 {
46 	uint8_t	fp_bytes[10];
47 };
48 
49 /* Contents of each SSE extended accumulator */
50 struct  xmmacc {
51 	uint8_t	xmm_bytes[16];
52 };
53 
54 /* Contents of the upper 16 bytes of each AVX extended accumulator */
55 struct  ymmacc {
56 	uint8_t  ymm_bytes[16];
57 };
58 
59 struct  envxmm {
60 	uint16_t	en_cw;		/* control word (16bits) */
61 	uint16_t	en_sw;		/* status word (16bits) */
62 	uint8_t		en_tw;		/* tag word (8bits) */
63 	uint8_t		en_zero;
64 	uint16_t	en_opcode;	/* opcode last executed (11 bits ) */
65 	uint64_t	en_rip;		/* floating point instruction pointer */
66 	uint64_t	en_rdp;		/* floating operand pointer */
67 	uint32_t	en_mxcsr;	/* SSE sontorol/status register */
68 	uint32_t	en_mxcsr_mask;	/* valid bits in mxcsr */
69 };
70 
71 struct  savefpu {
72 	struct	envxmm	sv_env;
73 	struct {
74 		struct fpacc87	fp_acc;
75 		uint8_t		fp_pad[6];      /* padding */
76 	} sv_fp[8];
77 	struct xmmacc	sv_xmm[16];
78 	uint8_t sv_pad[96];
79 } __aligned(16);
80 
81 struct xstate_hdr {
82 	uint64_t xstate_bv;
83 	uint8_t xstate_rsrv0[16];
84 	uint8_t	xstate_rsrv[40];
85 };
86 
87 struct savefpu_xstate {
88 	struct xstate_hdr sx_hd;
89 	struct ymmacc	sx_ymm[16];
90 };
91 
92 struct savefpu_ymm {
93 	struct	envxmm	sv_env;
94 	struct {
95 		struct fpacc87	fp_acc;
96 		int8_t		fp_pad[6];      /* padding */
97 	} sv_fp[8];
98 	struct xmmacc	sv_xmm[16];
99 	uint8_t sv_pad[96];
100 	struct savefpu_xstate sv_xstate;
101 } __aligned(64);
102 
103 #ifdef _KERNEL
104 
105 struct fpu_kern_ctx;
106 
107 #define	PCB_USER_FPU(pcb) (((pcb)->pcb_flags & PCB_KERNFPU) == 0)
108 
109 #define	XSAVE_AREA_ALIGN	64
110 
111 #endif
112 
113 /*
114  * The hardware default control word for i387's and later coprocessors is
115  * 0x37F, giving:
116  *
117  *	round to nearest
118  *	64-bit precision
119  *	all exceptions masked.
120  *
121  * FreeBSD/i386 uses 53 bit precision for things like fadd/fsub/fsqrt etc
122  * because of the difference between memory and fpu register stack arguments.
123  * If its using an intermediate fpu register, it has 80/64 bits to work
124  * with.  If it uses memory, it has 64/53 bits to work with.  However,
125  * gcc is aware of this and goes to a fair bit of trouble to make the
126  * best use of it.
127  *
128  * This is mostly academic for AMD64, because the ABI prefers the use
129  * SSE2 based math.  For FreeBSD/amd64, we go with the default settings.
130  */
131 #define	__INITIAL_FPUCW__	0x037F
132 #define	__INITIAL_FPUCW_I386__	0x127F
133 #define	__INITIAL_MXCSR__	0x1F80
134 #define	__INITIAL_MXCSR_MASK__	0xFFBF
135 
136 #ifdef _KERNEL
137 void	fpudna(void);
138 void	fpudrop(void);
139 void	fpuexit(struct thread *td);
140 int	fpuformat(void);
141 int	fpugetregs(struct thread *td);
142 void	fpuinit(void);
143 void	fpusave(void *addr);
144 int	fpusetregs(struct thread *td, struct savefpu *addr,
145 	    char *xfpustate, size_t xfpustate_size);
146 int	fpusetxstate(struct thread *td, char *xfpustate,
147 	    size_t xfpustate_size);
148 int	fputrap(void);
149 void	fpuuserinited(struct thread *td);
150 struct fpu_kern_ctx *fpu_kern_alloc_ctx(u_int flags);
151 void	fpu_kern_free_ctx(struct fpu_kern_ctx *ctx);
152 int	fpu_kern_enter(struct thread *td, struct fpu_kern_ctx *ctx,
153 	    u_int flags);
154 int	fpu_kern_leave(struct thread *td, struct fpu_kern_ctx *ctx);
155 int	fpu_kern_thread(u_int flags);
156 int	is_fpu_kern_thread(u_int flags);
157 
158 /*
159  * Flags for fpu_kern_alloc_ctx(), fpu_kern_enter() and fpu_kern_thread().
160  */
161 #define	FPU_KERN_NORMAL	0x0000
162 #define	FPU_KERN_NOWAIT	0x0001
163 
164 #endif
165 
166 #endif /* !_MACHINE_FPU_H_ */
167