debe445512
the actual FPU is enabled, while PCB_FPREGS indicates that the FPU state structure in the PCB is valid. This separation reflects the situation on FPU-less systems in which the FP state is used by the emulator but we don't actually want to try to turn on the non-existant FPU. Use this flag to save and restore FP regs properly on both AIM and Book-E. As a side effect, this sets up hard-FP and Altivec on Book-E CPUs with such abilities except for a trap handler to call enable_fpu()/enable_altivec().
153 lines
4.4 KiB
C
153 lines
4.4 KiB
C
/*-
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* Copyright (C) 1996 Wolfgang Solfrank.
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* Copyright (C) 1996 TooLs GmbH.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by TooLs GmbH.
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* 4. The name of TooLs GmbH may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $NetBSD: fpu.c,v 1.5 2001/07/22 11:29:46 wiz Exp $
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include <sys/param.h>
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#include <sys/proc.h>
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#include <sys/systm.h>
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#include <sys/limits.h>
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#include <machine/fpu.h>
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#include <machine/pcb.h>
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#include <machine/psl.h>
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void
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enable_fpu(struct thread *td)
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{
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int msr;
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struct pcb *pcb;
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struct trapframe *tf;
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pcb = td->td_pcb;
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tf = trapframe(td);
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/*
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* Save the thread's FPU CPU number, and set the CPU's current
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* FPU thread
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*/
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td->td_pcb->pcb_fpcpu = PCPU_GET(cpuid);
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PCPU_SET(fputhread, td);
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/*
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* Enable the FPU for when the thread returns from the exception.
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* If this is the first time the FPU has been used by the thread,
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* initialise the FPU registers and FPSCR to 0, and set the flag
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* to indicate that the FPU is in use.
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*/
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pcb->pcb_flags |= PCB_FPU;
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tf->srr1 |= PSL_FP;
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if (!(pcb->pcb_flags & PCB_FPREGS)) {
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memset(&pcb->pcb_fpu, 0, sizeof pcb->pcb_fpu);
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pcb->pcb_flags |= PCB_FPREGS;
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}
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/*
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* Temporarily enable floating-point so the registers
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* can be restored.
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*/
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msr = mfmsr();
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mtmsr(msr | PSL_FP);
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isync();
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/*
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* Load the floating point registers and FPSCR from the PCB.
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* (A value of 0xff for mtfsf specifies that all 8 4-bit fields
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* of the saved FPSCR are to be loaded from the FPU reg).
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*/
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__asm __volatile ("lfd 0,0(%0); mtfsf 0xff,0"
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:: "b"(&pcb->pcb_fpu.fpscr));
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#define LFP(n) __asm ("lfd " #n ", 0(%0)" \
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:: "b"(&pcb->pcb_fpu.fpr[n]));
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LFP(0); LFP(1); LFP(2); LFP(3);
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LFP(4); LFP(5); LFP(6); LFP(7);
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LFP(8); LFP(9); LFP(10); LFP(11);
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LFP(12); LFP(13); LFP(14); LFP(15);
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LFP(16); LFP(17); LFP(18); LFP(19);
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LFP(20); LFP(21); LFP(22); LFP(23);
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LFP(24); LFP(25); LFP(26); LFP(27);
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LFP(28); LFP(29); LFP(30); LFP(31);
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#undef LFP
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isync();
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mtmsr(msr);
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}
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void
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save_fpu(struct thread *td)
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{
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int msr;
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struct pcb *pcb;
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pcb = td->td_pcb;
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/*
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* Temporarily re-enable floating-point during the save
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*/
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msr = mfmsr();
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mtmsr(msr | PSL_FP);
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isync();
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/*
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* Save the floating-point registers and FPSCR to the PCB
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*/
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#define SFP(n) __asm ("stfd " #n ", 0(%0)" \
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:: "b"(&pcb->pcb_fpu.fpr[n]));
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SFP(0); SFP(1); SFP(2); SFP(3);
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SFP(4); SFP(5); SFP(6); SFP(7);
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SFP(8); SFP(9); SFP(10); SFP(11);
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SFP(12); SFP(13); SFP(14); SFP(15);
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SFP(16); SFP(17); SFP(18); SFP(19);
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SFP(20); SFP(21); SFP(22); SFP(23);
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SFP(24); SFP(25); SFP(26); SFP(27);
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SFP(28); SFP(29); SFP(30); SFP(31);
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#undef SFP
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__asm __volatile ("mffs 0; stfd 0,0(%0)" :: "b"(&pcb->pcb_fpu.fpscr));
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/*
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* Disable floating-point again
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*/
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isync();
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mtmsr(msr);
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/*
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* Clear the current fp thread and pcb's CPU id
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* XXX should this be left clear to allow lazy save/restore ?
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*/
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pcb->pcb_fpcpu = INT_MAX;
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PCPU_SET(fputhread, NULL);
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}
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