freebsd-dev/sys/amd64/include/sysarch.h
Konstantin Belousov 8c6f8f3d5b Add support for the extended FPU states on amd64, both for native
64bit and 32bit ABIs.  As a side-effect, it enables AVX on capable
CPUs.

In particular:

- Query the CPU support for XSAVE, list of the supported extensions
  and the required size of FPU save area. The hw.use_xsave tunable is
  provided for disabling XSAVE, and hw.xsave_mask may be used to
  select the enabled extensions.

- Remove the FPU save area from PCB and dynamically allocate the
  (run-time sized) user save area on the top of the kernel stack,
  right above the PCB. Reorganize the thread0 PCB initialization to
  postpone it after BSP is queried for save area size.

- The dumppcb, stoppcbs and susppcbs now do not carry the FPU state as
  well. FPU state is only useful for suspend, where it is saved in
  dynamically allocated suspfpusave area.

- Use XSAVE and XRSTOR to save/restore FPU state, if supported and
  enabled.

- Define new mcontext_t flag _MC_HASFPXSTATE, indicating that
  mcontext_t has a valid pointer to out-of-struct extended FPU
  state. Signal handlers are supplied with stack-allocated fpu
  state. The sigreturn(2) and setcontext(2) syscall honour the flag,
  allowing the signal handlers to inspect and manipilate extended
  state in the interrupted context.

- The getcontext(2) never returns extended state, since there is no
  place in the fixed-sized mcontext_t to place variable-sized save
  area. And, since mcontext_t is embedded into ucontext_t, makes it
  impossible to fix in a reasonable way.  Instead of extending
  getcontext(2) syscall, provide a sysarch(2) facility to query
  extended FPU state.

- Add ptrace(2) support for getting and setting extended state; while
  there, implement missed PT_I386_{GET,SET}XMMREGS for 32bit binaries.

- Change fpu_kern KPI to not expose struct fpu_kern_ctx layout to
  consumers, making it opaque. Internally, struct fpu_kern_ctx now
  contains a space for the extended state. Convert in-kernel consumers
  of fpu_kern KPI both on i386 and amd64.

First version of the support for AVX was submitted by Tim Bird
<tim.bird am sony com> on behalf of Sony. This version was written
from scratch.

Tested by:	pho (previous version), Yamagi Burmeister <lists yamagi org>
MFC after:	1 month
2012-01-21 17:45:27 +00:00

104 lines
3.1 KiB
C

/*-
* Copyright (c) 1993 The Regents of the University of California.
* All rights reserved.
*
* 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.
*
* $FreeBSD$
*/
/*
* Architecture specific syscalls (AMD64)
*/
#ifndef _MACHINE_SYSARCH_H_
#define _MACHINE_SYSARCH_H_
#include <sys/cdefs.h>
#define I386_GET_LDT 0
#define I386_SET_LDT 1
#define LDT_AUTO_ALLOC 0xffffffff
/* I386_IOPL */
#define I386_GET_IOPERM 3
#define I386_SET_IOPERM 4
/* XXX Not implementable #define I386_VM86 6 */
#define I386_GET_FSBASE 7
#define I386_SET_FSBASE 8
#define I386_GET_GSBASE 9
#define I386_SET_GSBASE 10
#define I386_GET_XFPUSTATE 11
/* Leave space for 0-127 for to avoid translating syscalls */
#define AMD64_GET_FSBASE 128
#define AMD64_SET_FSBASE 129
#define AMD64_GET_GSBASE 130
#define AMD64_SET_GSBASE 131
#define AMD64_GET_XFPUSTATE 132
struct i386_ldt_args {
unsigned int start;
struct user_segment_descriptor *descs __packed;
unsigned int num;
};
struct i386_ioperm_args {
unsigned int start;
unsigned int length;
int enable;
};
struct i386_get_xfpustate {
unsigned int addr;
int len;
};
struct amd64_get_xfpustate {
void *addr;
int len;
};
#ifndef _KERNEL
__BEGIN_DECLS
int amd64_get_fsbase(void **);
int amd64_get_gsbase(void **);
int amd64_set_fsbase(void *);
int amd64_set_gsbase(void *);
int sysarch(int, void *);
__END_DECLS
#else
struct thread;
union descriptor;
int amd64_get_ldt(struct thread *, struct i386_ldt_args *);
int amd64_set_ldt(struct thread *, struct i386_ldt_args *,
struct user_segment_descriptor *);
int amd64_get_ioperm(struct thread *, struct i386_ioperm_args *);
int amd64_set_ioperm(struct thread *, struct i386_ioperm_args *);
#endif
#endif /* !_MACHINE_SYSARCH_H_ */