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freebsd/sys/x86/include/fpu.h
John Baldwin 180e57e5c7 Improve support for XSAVE with debuggers.
- Dump an NT_X86_XSTATE note if XSAVE is in use. This note is designed
  to match what Linux does in that 1) it dumps the entire XSAVE area
  including the fxsave state, and 2) it stashes a copy of the current
  xsave mask in the unused padding between the fxsave state and the
  xstate header at the same location used by Linux.
- Teach readelf() to recognize NT_X86_XSTATE notes.
- Change PT_GET/SETXSTATE to take the entire XSAVE state instead of
  only the extra portion. This avoids having to always make two
  ptrace() calls to get or set the full XSAVE state.
- Add a PT_GET_XSTATE_INFO which returns the length of the current
  XSTATE save area (so the size of the buffer needed for PT_GETXSTATE)
  and the current XSAVE mask (%xcr0).

Differential Revision:	https://reviews.freebsd.org/D1193
Reviewed by:	kib
MFC after:	2 weeks
2014-11-21 20:53:17 +00:00

218 lines
6.5 KiB
C

/*-
* 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.
* 4. 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.
*
* from: @(#)npx.h 5.3 (Berkeley) 1/18/91
* $FreeBSD$
*/
/*
* Floating Point Data Structures and Constants
* W. Jolitz 1/90
*/
#ifndef _X86_FPU_H_
#define _X86_FPU_H_
/* Environment information of floating point unit. */
struct env87 {
int32_t en_cw; /* control word (16bits) */
int32_t en_sw; /* status word (16bits) */
int32_t en_tw; /* tag word (16bits) */
int32_t en_fip; /* fp instruction pointer */
uint16_t en_fcs; /* fp code segment selector */
uint16_t en_opcode; /* opcode last executed (11 bits) */
int32_t en_foo; /* fp operand offset */
int32_t en_fos; /* fp operand segment selector */
};
/* Contents of each x87 floating point accumulator. */
struct fpacc87 {
uint8_t fp_bytes[10];
};
/* Floating point context. (i386 fnsave/frstor) */
struct save87 {
struct env87 sv_env; /* floating point control/status */
struct fpacc87 sv_ac[8]; /* accumulator contents, 0-7 */
uint8_t sv_pad0[4]; /* saved status word (now unused) */
uint8_t sv_pad[64];
};
/* Contents of each SSE extended accumulator. */
struct xmmacc {
uint8_t xmm_bytes[16];
};
/* Contents of the upper 16 bytes of each AVX extended accumulator. */
struct ymmacc {
uint8_t ymm_bytes[16];
};
/* Rename structs below depending on machine architecture. */
#ifdef __i386__
#define __envxmm32 envxmm
#else
#define __envxmm32 envxmm32
#define __envxmm64 envxmm
#endif
struct __envxmm32 {
uint16_t en_cw; /* control word (16bits) */
uint16_t en_sw; /* status word (16bits) */
uint16_t en_tw; /* tag word (16bits) */
uint16_t en_opcode; /* opcode last executed (11 bits) */
uint32_t en_fip; /* fp instruction pointer */
uint16_t en_fcs; /* fp code segment selector */
uint16_t en_pad0; /* padding */
uint32_t en_foo; /* fp operand offset */
uint16_t en_fos; /* fp operand segment selector */
uint16_t en_pad1; /* padding */
uint32_t en_mxcsr; /* SSE control/status register */
uint32_t en_mxcsr_mask; /* valid bits in mxcsr */
};
struct __envxmm64 {
uint16_t en_cw; /* control word (16bits) */
uint16_t en_sw; /* status word (16bits) */
uint8_t en_tw; /* tag word (8bits) */
uint8_t en_zero;
uint16_t en_opcode; /* opcode last executed (11 bits ) */
uint64_t en_rip; /* fp instruction pointer */
uint64_t en_rdp; /* fp operand pointer */
uint32_t en_mxcsr; /* SSE control/status register */
uint32_t en_mxcsr_mask; /* valid bits in mxcsr */
};
/* Floating point context. (i386 fxsave/fxrstor) */
struct savexmm {
struct __envxmm32 sv_env;
struct {
struct fpacc87 fp_acc;
uint8_t fp_pad[6]; /* padding */
} sv_fp[8];
struct xmmacc sv_xmm[8];
uint8_t sv_pad[224];
} __aligned(16);
#ifdef __i386__
union savefpu {
struct save87 sv_87;
struct savexmm sv_xmm;
};
#else
/* Floating point context. (amd64 fxsave/fxrstor) */
struct savefpu {
struct __envxmm64 sv_env;
struct {
struct fpacc87 fp_acc;
uint8_t fp_pad[6]; /* padding */
} sv_fp[8];
struct xmmacc sv_xmm[16];
uint8_t sv_pad[96];
} __aligned(16);
#endif
struct xstate_hdr {
uint64_t xstate_bv;
uint64_t xstate_xcomp_bv;
uint8_t xstate_rsrv0[8];
uint8_t xstate_rsrv[40];
};
#define XSTATE_XCOMP_BV_COMPACT (1ULL << 63)
struct savexmm_xstate {
struct xstate_hdr sx_hd;
struct ymmacc sx_ymm[16];
};
struct savexmm_ymm {
struct __envxmm32 sv_env;
struct {
struct fpacc87 fp_acc;
int8_t fp_pad[6]; /* padding */
} sv_fp[8];
struct xmmacc sv_xmm[16];
uint8_t sv_pad[96];
struct savexmm_xstate sv_xstate;
} __aligned(64);
struct savefpu_xstate {
struct xstate_hdr sx_hd;
struct ymmacc sx_ymm[16];
};
struct savefpu_ymm {
struct __envxmm64 sv_env;
struct {
struct fpacc87 fp_acc;
int8_t fp_pad[6]; /* padding */
} sv_fp[8];
struct xmmacc sv_xmm[16];
uint8_t sv_pad[96];
struct savefpu_xstate sv_xstate;
} __aligned(64);
#undef __envxmm32
#undef __envxmm64
/*
* The hardware default control word for i387's and later coprocessors is
* 0x37F, giving:
*
* round to nearest
* 64-bit precision
* all exceptions masked.
*
* FreeBSD/i386 uses 53 bit precision for things like fadd/fsub/fsqrt etc
* because of the difference between memory and fpu register stack arguments.
* If its using an intermediate fpu register, it has 80/64 bits to work
* with. If it uses memory, it has 64/53 bits to work with. However,
* gcc is aware of this and goes to a fair bit of trouble to make the
* best use of it.
*
* This is mostly academic for AMD64, because the ABI prefers the use
* SSE2 based math. For FreeBSD/amd64, we go with the default settings.
*/
#define __INITIAL_FPUCW__ 0x037F
#define __INITIAL_FPUCW_I386__ 0x127F
#define __INITIAL_NPXCW__ __INITIAL_FPUCW_I386__
#define __INITIAL_MXCSR__ 0x1F80
#define __INITIAL_MXCSR_MASK__ 0xFFBF
/*
* The current value of %xcr0 is saved in the sv_pad[] field of the FPU
* state in the NT_X86_XSTATE note in core dumps. This offset is chosen
* to match the offset used by NT_X86_XSTATE in other systems.
*/
#define X86_XSTATE_XCR0_OFFSET 464
#endif /* !_X86_FPU_H_ */