xref: /openbsd-src/sys/arch/amd64/include/fpu.h (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: fpu.h,v 1.11 2015/03/25 21:05:18 kettenis Exp $	*/
2 /*	$NetBSD: fpu.h,v 1.1 2003/04/26 18:39:40 fvdl Exp $	*/
3 
4 #ifndef	_MACHINE_FPU_H_
5 #define	_MACHINE_FPU_H_
6 
7 #include <sys/types.h>
8 
9 /*
10  * amd64 only uses the extended save/restore format used
11  * by fxsave/fsrestore, to always deal with the SSE registers,
12  * which are part of the ABI to pass floating point values.
13  * Must be stored in memory on a 16-byte boundary.
14  */
15 
16 struct fxsave64 {
17 	u_int16_t  fx_fcw;
18 	u_int16_t  fx_fsw;
19 	u_int8_t   fx_ftw;
20 	u_int8_t   fx_unused1;
21 	u_int16_t  fx_fop;
22 	u_int64_t  fx_rip;
23 	u_int64_t  fx_rdp;
24 	u_int32_t  fx_mxcsr;
25 	u_int32_t  fx_mxcsr_mask;
26 	u_int64_t  fx_st[8][2];   /* 8 normal FP regs */
27 	u_int64_t  fx_xmm[16][2]; /* 16 SSE2 registers */
28 	u_int8_t   fx_unused3[96];
29 } __packed;
30 
31 struct xstate_hdr {
32 	uint64_t	xstate_bv;
33 	uint64_t	xstate_xcomp_bv;
34 	uint8_t		xstate_rsrv0[0];
35 	uint8_t		xstate_rsrv[40];
36 } __packed;
37 
38 struct savefpu {
39 	struct fxsave64 fp_fxsave;	/* see above */
40 	struct xstate_hdr fp_xstate;
41 	u_int64_t fp_ymm[16][2];
42 	u_int16_t fp_ex_sw;		/* saved status from last exception */
43 	u_int16_t fp_ex_tw;		/* saved tag from last exception */
44 };
45 
46 /*
47  * The i387 defaults to Intel extended precision mode and round to nearest,
48  * with all exceptions masked.
49  */
50 #define	__INITIAL_NPXCW__	0x037f
51 #define __INITIAL_MXCSR__ 	0x1f80
52 #define __INITIAL_MXCSR_MASK__	0xffbf
53 
54 #ifdef _KERNEL
55 /*
56  * XXX
57  */
58 struct trapframe;
59 struct cpu_info;
60 
61 extern size_t	fpu_save_len;
62 extern uint32_t	fpu_mxcsr_mask;
63 extern uint64_t	xsave_mask;
64 
65 void fpuinit(struct cpu_info *);
66 void fpudrop(void);
67 void fpudiscard(struct proc *);
68 void fputrap(struct trapframe *);
69 void fpusave_proc(struct proc *, int);
70 void fpusave_cpu(struct cpu_info *, int);
71 void fpu_kernel_enter(void);
72 void fpu_kernel_exit(void);
73 
74 #endif
75 
76 #endif /* _MACHINE_FPU_H_ */
77