/*      $OpenBSD: npx.h,v 1.20 2021/03/11 11:16:57 jsg Exp $    */
/*      $NetBSD: npx.h,v 1.11 1994/10/27 04:16:11 cgd Exp $     */

/*-
 * Copyright (c) 1990 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * William Jolitz.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *      @(#)npx.h       5.3 (Berkeley) 1/18/91
 */

/*
 * 287/387 NPX Coprocessor Data Structures and Constants
 * W. Jolitz 1/90
 */

#ifndef _MACHINE_NPX_H_
#define _MACHINE_NPX_H_

/* Environment information of floating point unit */
struct  env87 {
        long    en_cw;          /* control word (16bits) */
        long    en_sw;          /* status word (16bits) */
        long    en_tw;          /* tag word (16bits) */
        long    en_fip;         /* floating point instruction pointer */
        u_short en_fcs;         /* floating code segment selector */
        u_short en_opcode;      /* opcode last executed (11 bits ) */
        long    en_foo;         /* floating operand offset */
        long    en_fos;         /* floating operand segment selector */
};

#define EN_SW_IE        0x0001  /* invalid operation */
#define EN_SW_DE        0x0002  /* denormal */
#define EN_SW_ZE        0x0004  /* divide by zero */
#define EN_SW_OE        0x0008  /* overflow */
#define EN_SW_UE        0x0010  /* underflow */
#define EN_SW_PE        0x0020  /* loss of precision */

/* Contents of each floating point accumulator */
struct  fpacc87 {
#ifdef dontdef  /* too unportable */
        u_long  fp_mantlo;      /* mantissa low (31:0) */
        u_long  fp_manthi;      /* mantissa high (63:32) */
        int     fp_exp:15;      /* exponent */
        int     fp_sgn:1;       /* mantissa sign */
#else
        u_char  fp_bytes[10];
#endif
};

/* Floating point and emulator context */
struct  save87 {
        struct  env87 sv_env;           /* floating point control/status */
        struct  fpacc87 sv_ac[8];       /* accumulator contents, 0-7 */
        u_long  sv_ex_sw;               /* status word for last exception */
        u_long  sv_ex_tw;               /* tag word for last exception */
};

/* Environment of FPU/MMX/SSE/SSE2. */
struct envxmm {
/*0*/   uint16_t en_cw;         /* FPU Control Word */
        uint16_t en_sw;         /* FPU Status Word */
        uint8_t  en_tw;         /* FPU Tag Word (abridged) */
        uint8_t  en_rsvd0;
        uint16_t en_opcode;     /* FPU Opcode */
        uint32_t en_fip;        /* FPU Instruction Pointer */
        uint16_t en_fcs;        /* FPU IP selector */
        uint16_t en_rsvd1;
/*16*/  uint32_t en_foo;        /* FPU Data pointer */
        uint16_t en_fos;        /* FPU Data pointer selector */
        uint16_t en_rsvd2;
        uint32_t en_mxcsr;      /* MXCSR Register State */
        uint32_t en_mxcsr_mask; /* Mask for valid MXCSR bits (may be 0) */
};

/* FPU registers in the extended save format. */
struct fpaccxmm {
        uint8_t fp_bytes[10];
        uint8_t fp_rsvd[6];
};

/* SSE/SSE2 registers. */
struct xmmreg {
        uint8_t sse_bytes[16];
};

/* FPU/MMX/SSE/SSE2 context */
struct savexmm {
        struct envxmm sv_env;           /* control/status context */
        struct fpaccxmm sv_ac[8];       /* ST/MM regs */
        struct xmmreg sv_xmmregs[8];    /* XMM regs */
        uint8_t sv_rsvd[16 * 14];
        /* 512-bytes --- end of hardware portion of save area */
        uint32_t sv_ex_sw;              /* saved SW from last exception */
        uint32_t sv_ex_tw;              /* saved TW from last exception */
};

union savefpu {
        struct save87 sv_87;
        struct savexmm sv_xmm;
};

#define __INITIAL_NPXCW__       0x037f

/*
 * The default MXCSR value at reset is 0x1f80, IA-32 Instruction
 * Set Reference, pg. 3-369.
 */
#define __INITIAL_MXCSR__       0x1f80
#define __INITIAL_MXCSR_MASK__  0xffbf

/*
 * The standard control word from finit is 0x37F, giving:
 *      round to nearest
 *      64-bit precision
 *      all exceptions masked.
 */

void    process_xmm_to_s87(const struct savexmm *, struct save87 *);
void    process_s87_to_xmm(const struct save87 *, struct savexmm *);

struct cpu_info;
struct trapframe;

extern uint32_t fpu_mxcsr_mask;

void    npxinit(struct cpu_info *);
void    npxtrap(struct trapframe *);
void    fpu_kernel_enter(void);
void    fpu_kernel_exit(void);

#endif /* !_MACHINE_NPX_H_ */