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/*
* Copyright (c) 1998, 1999 University of Utah and the Flux Group.
* All rights reserved.
*
* This file is part of the Flux OSKit. The OSKit is free software, also known
* as "open source;" you can redistribute it and/or modify it under the terms
* of the GNU General Public License (GPL), version 2, as published by the Free
* Software Foundation (FSF). To explore alternate licensing terms, contact
* the University of Utah at csl-dist@cs.utah.edu or +1-801-585-3271.
*
* The OSKit 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 GPL for more details. You should have
* received a copy of the GPL along with the OSKit; see the file COPYING. If
* not, write to the FSF, 59 Temple Place #330, Boston, MA 02111-1307, USA.
*/
/*
* Copyright (c) UNIX System Laboratories, Inc. All or some portions
* of this file are derived from material licensed to the
* University of California by American Telephone and Telegraph Co.
* or UNIX System Laboratories, Inc. and are reproduced herein with
* the permission of UNIX System Laboratories, Inc.
*/
/*-
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 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.
*
*/
/*
* Task switch code.
*/
#include <oskit/config.h>
#include <oskit/x86/asm.h>
#include <oskit/x86/paging.h>
#include <threads/pthread_internal.h>
#include <threads/x86/pcb.h>
.text
.align 8
.globl EXT(thread_switch_usermode)
LEXT(thread_switch_usermode)
/* switch to new process. first, save context as needed */
movl 12(%esp),%ecx /* Current thread */
movl THREAD_PPCB(%ecx),%ecx
movl (%esp),%eax /* Hardware registers */
movl %eax,PCB_EIP(%ecx)
movl %ebx,PCB_EBX(%ecx)
movl %esp,PCB_ESP(%ecx)
movl %ebp,PCB_EBP(%ecx)
movl %esi,PCB_ESI(%ecx)
movl %edi,PCB_EDI(%ecx)
fsave PCB_FSTATE(%ecx)
/*
* Save is done, switch to new thread.
*/
movl 4(%esp),%ecx /* New thread */
movl %esp,%eax /* Save stack pointer */
/* restore context */
movl THREAD_PPCB(%ecx),%edx
frstor PCB_FSTATE(%edx)
movl PCB_ESP(%edx),%esp
movl PCB_EBP(%edx),%ebp
movl PCB_ESI(%edx),%esi
movl PCB_EDI(%edx),%edi
movl PCB_EIP(%edx),%ebx
movl %ebx,(%esp)
movl PCB_EBX(%edx),%ebx
/*
* Unlock the lock
*/
movl 8(%eax),%eax /* Lock to unlock */
xorl %ecx,%ecx
xchgl %ecx,(%eax)
movl $0,%eax
ret
.align 8
.globl EXT(thread_switch_realmode)
LEXT(thread_switch_realmode)
/* switch to new process. first, save context as needed */
movl 12(%esp),%ecx /* Current Thread */
movl THREAD_PPCB(%ecx),%ecx
movl (%esp),%eax /* Hardware registers */
movl %eax,PCB_EIP(%ecx)
movl %ebx,PCB_EBX(%ecx)
movl %esp,PCB_ESP(%ecx)
movl %ebp,PCB_EBP(%ecx)
movl %esi,PCB_ESI(%ecx)
movl %edi,PCB_EDI(%ecx)
#ifdef SMP
fsave PCB_FSTATE(%ecx)
#endif
/*
* Save is done, switch to new thread.
*/
movl 4(%esp),%ecx /* New thread */
movl %esp,%eax /* Save stack pointer */
/* restore context */
movl THREAD_PPCB(%ecx),%edx
#ifdef SMP
frstor PCB_FSTATE(%edx)
#endif
movl PCB_ESP(%edx),%esp
movl PCB_EBP(%edx),%ebp
movl PCB_ESI(%edx),%esi
movl PCB_EDI(%edx),%edi
movl PCB_EIP(%edx),%ebx
movl %ebx,(%esp)
movl PCB_EBX(%edx),%ebx
#ifndef SMP
/*
* The floating point is disabled if the thread being switched into
* is not the current owner of the FPU.
*/
clts
cmpl %ecx,EXT(owner_fpu)
je skipts
mov %cr0,%edx
orl $0x8,%edx
mov %edx,%cr0
skipts:
#endif
/*
* Unlock the lock
*/
movl 8(%eax),%eax /* Lock to unlock */
xorl %ecx,%ecx
xchgl %ecx,(%eax)
movl $0,%eax
ret
#ifndef SMP
/*
* FPU fault handler. Switch the FPU context by saving the state off
* and restoring the current threads state.
*/
.align 8
.globl EXT(pthread_fpu_trap_handler)
LEXT(pthread_fpu_trap_handler)
/*
* Turn on access to FP unit.
*/
clts
/*
* Get the owner thread of the floating point unit and save to it.
*/
movl EXT(owner_fpu),%ecx
movl THREAD_PPCB(%ecx),%edx
fsave PCB_FSTATE(%edx)
/*
* Get the current thread and restore the floating point unut.
*/
movl EXT(threads_curthreads),%ecx
movl THREAD_PPCB(%ecx),%edx
frstor PCB_FSTATE(%edx)
movl %ecx,EXT(owner_fpu)
movl $0,%eax
ret
#endif
/*
* ffs(value)
* finds the first bit set in value and returns the index of
* that bit. Bits are numbered starting from 1, starting at the
* rightmost bit. A return value of 0 means that the argument
* was zero.
*
* Written by:
* J.T. Conklin (jtc@wimsey.com), Winning Strategies, Inc.
*/
.align 8
.globl EXT(ffs)
LEXT(ffs)
bsfl 4(%esp),%eax
jz L1 /* ZF is set if all bits are 0 */
incl %eax /* bits numbered from 1, not 0 */
ret
.align 2
L1: xorl %eax,%eax /* clear result */
ret
/*
* thread_fpuinit(src, dst)
*/
.align 8
.globl EXT(thread_fpuinit)
LEXT(thread_fpuinit)
/*
* Save current state.
*/
movl 4(%esp),%eax
fsave 0(%eax)
/*
* Reinit and save to new thread fstate.
*/
finit
movl 8(%esp),%eax
fsave 0(%eax)
/*
* And restore old state.
*/
movl 4(%esp),%eax
frstor 0(%eax)
ret
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