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/*-
* Copyright (C) 1996 Wolfgang Solfrank.
* Copyright (C) 1996 TooLs GmbH.
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by TooLs GmbH.
* 4. The name of TooLs GmbH may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``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 TOOLS GMBH 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.
*
* $NetBSD: fpu.c,v 1.5 2001/07/22 11:29:46 wiz Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/limits.h>
#include <machine/fpu.h>
#include <machine/pcb.h>
#include <machine/psl.h>
void
enable_fpu(struct thread *td)
{
int msr;
struct pcb *pcb;
struct trapframe *tf;
pcb = td->td_pcb;
tf = trapframe(td);
/*
* Save the thread's FPU CPU number, and set the CPU's current
* FPU thread
*/
td->td_pcb->pcb_fpcpu = PCPU_GET(cpuid);
PCPU_SET(fputhread, td);
/*
* Enable the FPU for when the thread returns from the exception.
* If this is the first time the FPU has been used by the thread,
* initialise the FPU registers and FPSCR to 0, and set the flag
* to indicate that the FPU is in use.
*/
tf->srr1 |= PSL_FP;
if (!(pcb->pcb_flags & PCB_FPU)) {
memset(&pcb->pcb_fpu, 0, sizeof pcb->pcb_fpu);
pcb->pcb_flags |= PCB_FPU;
}
/*
* Temporarily enable floating-point so the registers
* can be restored.
*/
msr = mfmsr();
mtmsr(msr | PSL_FP);
isync();
/*
* Load the floating point registers and FPSCR from the PCB.
* (A value of 0xff for mtfsf specifies that all 8 4-bit fields
* of the saved FPSCR are to be loaded from the FPU reg).
*/
__asm __volatile ("lfd 0,0(%0); mtfsf 0xff,0"
:: "b"(&pcb->pcb_fpu.fpscr));
#define LFP(n) __asm ("lfd " #n ", 0(%0)" \
:: "b"(&pcb->pcb_fpu.fpr[n]));
LFP(0); LFP(1); LFP(2); LFP(3);
LFP(4); LFP(5); LFP(6); LFP(7);
LFP(8); LFP(9); LFP(10); LFP(11);
LFP(12); LFP(13); LFP(14); LFP(15);
LFP(16); LFP(17); LFP(18); LFP(19);
LFP(20); LFP(21); LFP(22); LFP(23);
LFP(24); LFP(25); LFP(26); LFP(27);
LFP(28); LFP(29); LFP(30); LFP(31);
#undef LFP
isync();
mtmsr(msr);
}
void
save_fpu(struct thread *td)
{
int msr;
struct pcb *pcb;
pcb = td->td_pcb;
/*
* Temporarily re-enable floating-point during the save
*/
msr = mfmsr();
mtmsr(msr | PSL_FP);
isync();
/*
* Save the floating-point registers and FPSCR to the PCB
*/
#define SFP(n) __asm ("stfd " #n ", 0(%0)" \
:: "b"(&pcb->pcb_fpu.fpr[n]));
SFP(0); SFP(1); SFP(2); SFP(3);
SFP(4); SFP(5); SFP(6); SFP(7);
SFP(8); SFP(9); SFP(10); SFP(11);
SFP(12); SFP(13); SFP(14); SFP(15);
SFP(16); SFP(17); SFP(18); SFP(19);
SFP(20); SFP(21); SFP(22); SFP(23);
SFP(24); SFP(25); SFP(26); SFP(27);
SFP(28); SFP(29); SFP(30); SFP(31);
#undef SFP
__asm __volatile ("mffs 0; stfd 0,0(%0)" :: "b"(&pcb->pcb_fpu.fpscr));
/*
* Disable floating-point again
*/
isync();
mtmsr(msr);
/*
* Clear the current fp thread and pcb's CPU id
* XXX should this be left clear to allow lazy save/restore ?
*/
pcb->pcb_fpcpu = INT_MAX;
PCPU_SET(fputhread, NULL);
}
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