linux/arch/arm/nwfpe/fpa11.h
Richard Purdie f148af2593 [PATCH] ARM: 2837/2: Re: ARM: Make NWFPE preempt safe
Patch from Richard Purdie

NWFPE used global variables which meant it wasn't safe for use with
preemptive kernels. This patch removes them and communicates the
information between functions in a preempt safe manner. Generation
of some exceptions was broken and this has also been corrected.
Tests with glibc's maths test suite show no change in the results
before/after this patch.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2005-08-03 19:49:17 +01:00

99 lines
3.0 KiB
C

/*
NetWinder Floating Point Emulator
(c) Rebel.com, 1998-1999
Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#ifndef __FPA11_H__
#define __FPA11_H__
#define GET_FPA11() ((FPA11 *)(&current_thread_info()->fpstate))
/*
* The processes registers are always at the very top of the 8K
* stack+task struct. Use the same method as 'current' uses to
* reach them.
*/
#define GET_USERREG() ((struct pt_regs *)(THREAD_START_SP + (unsigned long)current_thread_info()) - 1)
#include <linux/config.h>
#include <linux/thread_info.h>
/* includes */
#include "fpsr.h" /* FP control and status register definitions */
#include "milieu.h"
struct roundingData {
int8 mode;
int8 precision;
signed char exception;
};
#include "softfloat.h"
#define typeNone 0x00
#define typeSingle 0x01
#define typeDouble 0x02
#define typeExtended 0x03
/*
* This must be no more and no less than 12 bytes.
*/
typedef union tagFPREG {
float32 fSingle;
float64 fDouble;
#ifdef CONFIG_FPE_NWFPE_XP
floatx80 fExtended;
#else
int padding[3];
#endif
} FPREG;
/*
* FPA11 device model.
*
* This structure is exported to user space. Do not re-order.
* Only add new stuff to the end, and do not change the size of
* any element. Elements of this structure are used by user
* space, and must match struct user_fp in include/asm-arm/user.h.
* We include the byte offsets below for documentation purposes.
*
* The size of this structure and FPREG are checked by fpmodule.c
* on initialisation. If the rules have been broken, NWFPE will
* not initialise.
*/
typedef struct tagFPA11 {
/* 0 */ FPREG fpreg[8]; /* 8 floating point registers */
/* 96 */ FPSR fpsr; /* floating point status register */
/* 100 */ FPCR fpcr; /* floating point control register */
/* 104 */ unsigned char fType[8]; /* type of floating point value held in
floating point registers. One of
none, single, double or extended. */
/* 112 */ int initflag; /* this is special. The kernel guarantees
to set it to 0 when a thread is launched,
so we can use it to detect whether this
instance of the emulator needs to be
initialised. */
} FPA11;
extern int8 SetRoundingMode(const unsigned int);
extern int8 SetRoundingPrecision(const unsigned int);
extern void nwfpe_init_fpa(union fp_state *fp);
#endif