8b8aa9c1e6
The case in cpu_switch() where there isn't a higher priority thread (choosethread() == curthread) uses r4 as the PCB context pointer. However, the use of r4 after the label L2 is incorrect, since it was probably trashed by the call to choosethread, and in any case was set up to curthread at the start of the routine. This condition will occur when an interrupt thread schedules a netisr, which is a lower priority thread. Another (probably unnecessary) difference is that I was paranoid about register trashing, so I decided to save r2 and r13 as well. Submitted by: Peter Grehan <peterg@ptree32.com.au>
156 lines
5.3 KiB
ArmAsm
156 lines
5.3 KiB
ArmAsm
/* $FreeBSD$ */
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/* $NetBSD: locore.S,v 1.24 2000/05/31 05:09:17 thorpej Exp $ */
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/*
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* Copyright (C) 2001 Benno Rice
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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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*
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* THIS SOFTWARE IS PROVIDED BY Benno Rice ``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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/*
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* Copyright (C) 1995, 1996 Wolfgang Solfrank.
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* Copyright (C) 1995, 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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#include "assym.s"
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#include <sys/syscall.h>
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#include <machine/trap.h>
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#include <machine/param.h>
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#include <machine/sr.h>
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#include <machine/psl.h>
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#include <machine/asm.h>
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/*
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* void cpu_switch()
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* Find a runnable thread and switch to it.
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*/
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ENTRY(cpu_switch)
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mfsprg %r3,0 /* Get the pcpu pointer */
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lwz %r4,PC_CURTHREAD(%r3) /* Get the current thread */
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lwz %r3,TD_PCB(%r4) /* Get a pointer to the PCB */
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mr %r12,%r2
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stmw %r12,PCB_CONTEXT(%r3) /* Save the non-volatile GP regs */
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mr %r14,%r3 /* Copy the current pcb pointer */
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mr %r15,%r4 /* ... and the curthread pointer */
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mfcr %r16 /* Save the condition register */
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stw %r16,PCB_CR(%r3)
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mflr %r16 /* Save the link register */
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stw %r16,PCB_LR(%r3)
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stw %r1,PCB_SP(%r3) /* Save the stack pointer */
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#if 0
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lwz %r29,PCB_FLAGS(%r3)
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andi. %r9, %r29, 1 /* XXX - don't hard code */
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beq .L1
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bl save_fpu
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#endif
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.L1:
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bl choosethread /* Find a new thread to run */
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cmplw 0,%r3,%r15 /* Compare to curthread */
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beq .L2 /* If it's the same, we're done */
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mr %r16,%r3 /* Save off the (struct thread *) */
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mr %r3,%r15
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bl pmap_deactivate /* Deactivate the current pmap */
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mr %r3,%r16
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bl pmap_activate /* Activate the new address space */
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mfsprg %r4,0 /* Get the pcpu pointer */
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stw %r16,PC_CURTHREAD(%r4) /* Store new current thread */
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mr %r3,%r16 /* and save in r3 */
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lwz %r16,TD_PCB(%r16) /* Store new current PCB */
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stw %r16,PC_CURPCB(%r4)
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#if 0
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lwz %r29, PCB_FLAGS(%r4) /* Restore FPU regs if needed */
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andi. %r9, %r29, 1
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beq .L2
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mr %r3, %r4
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bl enable_fpu
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#endif
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/* thread to restore is in r3 */
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.L2:
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lwz %r3, TD_PCB(%r3)
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lmw %r12,PCB_CONTEXT(%r3) /* Load the non-volatile GP regs */
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mr %r2,%r12
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lwz %r5,PCB_CR(%r3) /* Load the condition register */
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mtcr %r5
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lwz %r5,PCB_LR(%r3) /* Load the link register */
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mtlr %r5
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lwz %r1,PCB_SP(%r3) /* Load the stack pointer */
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blr
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/*
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* savectx(pcb)
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* Update pcb, saving current processor state
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*/
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ENTRY(savectx)
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mr %r12,%r2
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stmw %r12,PCB_CONTEXT(%r3) /* Save the non-volatile GP regs */
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mfcr %r4 /* Save the condition register */
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stw %r4,PCB_CONTEXT(%r3)
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blr
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/*
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* fork_trampoline()
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* Set up the return from cpu_fork()
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*/
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ENTRY(fork_trampoline)
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lwz %r3,CF_FUNC(%r1)
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lwz %r4,CF_ARG0(%r1)
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lwz %r5,CF_ARG1(%r1)
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bl fork_exit
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addi %r1,%r1,4
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b trapexit
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