Files
ios2024/code/threads/switch.S

751 lines
19 KiB
ArmAsm

/* switch.s
* Machine dependent context switch routines. DO NOT MODIFY THESE!
*
* Context switching is inherently machine dependent, since
* the registers to be saved, how to set up an initial
* call frame, etc, are all specific to a processor architecture.
*
* This file currently supports the following architectures:
* DEC MIPS (DECMIPS)
* DEC Alpha (ALPHA)
* SUN SPARC (SPARC)
* HP PA-RISC (PARISC)
* Intel 386 (x86)
* IBM RS6000 (PowerPC) -- I hope it will also work for Mac PowerPC
*
* We define two routines for each architecture:
*
* ThreadRoot(InitialPC, InitialArg, WhenDonePC, StartupPC)
* InitialPC - The program counter of the procedure to run
* in this thread.
* InitialArg - The single argument to the thread.
* WhenDonePC - The routine to call when the thread returns.
* StartupPC - Routine to call when the thread is started.
*
* ThreadRoot is called from the SWITCH() routine to start
* a thread for the first time.
*
* SWITCH(oldThread, newThread)
* oldThread - The current thread that was running, where the
* CPU register state is to be saved.
* newThread - The new thread to be run, where the CPU register
* state is to be loaded from.
*/
/*
Copyright (c) 1992-1996 The Regents of the University of California.
All rights reserved. See copyright.h for copyright notice and limitation
of liability and disclaimer of warranty provisions.
*/
#include "copyright.h"
#include "switch.h"
#ifdef DECMIPS
/* Symbolic register names */
#define z $0 /* zero register */
#define a0 $4 /* argument registers */
#define a1 $5
#define s0 $16 /* callee saved */
#define s1 $17
#define s2 $18
#define s3 $19
#define s4 $20
#define s5 $21
#define s6 $22
#define s7 $23
#define sp $29 /* stack pointer */
#define fp $30 /* frame pointer */
#define ra $31 /* return address */
.text
.align 2
.globl ThreadRoot
.ent ThreadRoot,0
ThreadRoot:
or fp,z,z # Clearing the frame pointer here
# makes gdb backtraces of thread stacks
# end here (I hope!)
jal StartupPC # call startup procedure
move a0, InitialArg
jal InitialPC # call main procedure
jal WhenDonePC # when done, call clean up procedure
# NEVER REACHED
.end ThreadRoot
# a0 -- pointer to old Thread
# a1 -- pointer to new Thread
.globl SWITCH
.ent SWITCH,0
SWITCH:
sw sp, SP(a0) # save new stack pointer
sw s0, S0(a0) # save all the callee-save registers
sw s1, S1(a0)
sw s2, S2(a0)
sw s3, S3(a0)
sw s4, S4(a0)
sw s5, S5(a0)
sw s6, S6(a0)
sw s7, S7(a0)
sw fp, FP(a0) # save frame pointer
sw ra, PC(a0) # save return address
lw sp, SP(a1) # load the new stack pointer
lw s0, S0(a1) # load the callee-save registers
lw s1, S1(a1)
lw s2, S2(a1)
lw s3, S3(a1)
lw s4, S4(a1)
lw s5, S5(a1)
lw s6, S6(a1)
lw s7, S7(a1)
lw fp, FP(a1)
lw ra, PC(a1) # load the return address
j ra
.end SWITCH
#endif // DECMIPS
#ifdef SPARC
/* NOTE! These files appear not to exist on Solaris --
* you need to find where (the SPARC-specific) MINFRAME, ST_FLUSH_WINDOWS, ...
* are defined. (I don't have a Solaris machine, so I have no way to tell.)
*/
#ifdef SOLARIS
#include <sys/trap.h>
#include <sys/asm_linkage.h>
#else
#include <sun4/trap.h>
#include <sun4/asm_linkage.h>
#endif
.seg "text"
/* SPECIAL to the SPARC:
* The first two instruction of ThreadRoot are skipped because
* the address of ThreadRoot is made the return address of SWITCH()
* by the routine Thread::StackAllocate. SWITCH() jumps here on the
* "ret" instruction which is really at "jmp %o7+8". The 8 skips the
* two nops at the beginning of the routine.
*/
#ifdef SOLARIS
.globl ThreadRoot
ThreadRoot:
#else
.globl _ThreadRoot
_ThreadRoot:
#endif
nop ; nop /* These 2 nops are skipped because we are called
* with a jmp+8 instruction. */
clr %fp /* Clearing the frame pointer makes gdb backtraces
* of thread stacks end here. */
/* Currently the arguments are in out registers we
* save them into local registers so they won't be
* trashed during the calls we make. */
mov InitialPC, %l0
mov InitialArg, %l1
mov WhenDonePC, %l2
/* Execute the code:
* call StartupPC();
* call InitialPC(InitialArg);
* call WhenDonePC();
*/
call StartupPC,0
nop
call %l0, 1
mov %l1, %o0 /* Using delay slot to setup argument to InitialPC */
call %l2, 0
nop
/* WhenDonePC call should never return. If it does
* we execute a trap into the debugger. */
ta ST_BREAKPOINT
#ifdef SOLARIS
.globl SWITCH
SWITCH:
#else
.globl _SWITCH
_SWITCH:
#endif
save %sp, -SA(MINFRAME), %sp
st %fp, [%i0]
st %i0, [%i0+I0]
st %i1, [%i0+I1]
st %i2, [%i0+I2]
st %i3, [%i0+I3]
st %i4, [%i0+I4]
st %i5, [%i0+I5]
st %i7, [%i0+I7]
ta ST_FLUSH_WINDOWS
nop
mov %i1, %l0
ld [%l0+I0], %i0
ld [%l0+I1], %i1
ld [%l0+I2], %i2
ld [%l0+I3], %i3
ld [%l0+I4], %i4
ld [%l0+I5], %i5
ld [%l0+I7], %i7
ld [%l0], %i6
ret
restore
#endif // SPARC
#ifdef PARISC
;rp = r2, sp = r30
;arg0 = r26, arg1 = r25, arg2 = r24, arg3 = r23
.SPACE $TEXT$
.SUBSPA $CODE$
ThreadRoot
.PROC
.CALLINFO CALLER,FRAME=0
.ENTER
.CALL
ble 0(%r6) ;call StartupPC
stw %r31, -24(%sp) ;put return address in proper stack
;location for StartupPC export stub.
or %r4, 0, %arg0 ;load InitialArg
.CALL ;in=26
ble 0(%r3) ;call InitialPC
stw %r31, -24(%sp) ;put return address in proper stack
;location for InitialPC export stub.
.CALL
ble 0(%r5) ;call WhenDonePC
stw %r31, -24(%sp) ;put return address in proper stack
;location for StartupPC export stub.
.LEAVE
.PROCEND
SWITCH
.PROC
.CALLINFO CALLER,FRAME=0
.ENTRY
; save process state of oldThread
stw %sp, SP(%arg0) ;save stack pointer
stw %r3, S0(%arg0) ;save callee-save registers
stw %r4, S1(%arg0)
stw %r5, S2(%arg0)
stw %r6, S3(%arg0)
stw %r7, S4(%arg0)
stw %r8, S5(%arg0)
stw %r9, S6(%arg0)
stw %r10, S7(%arg0)
stw %r11, S8(%arg0)
stw %r12, S9(%arg0)
stw %r13, S10(%arg0)
stw %r14, S11(%arg0)
stw %r15, S12(%arg0)
stw %r16, S13(%arg0)
stw %r17, S14(%arg0)
stw %r18, S15(%arg0)
stw %rp, PC(%arg0) ;save program counter
; restore process state of nextThread
ldw SP(%arg1), %sp ;restore stack pointer
ldw S0(%arg1), %r3 ;restore callee-save registers
ldw S1(%arg1), %r4
ldw S2(%arg1), %r5
ldw S3(%arg1), %r6
ldw S4(%arg1), %r7
ldw S5(%arg1), %r8
ldw S6(%arg1), %r9
ldw S7(%arg1), %r10
ldw S8(%arg1), %r11
ldw S9(%arg1), %r12
ldw S10(%arg1), %r13
ldw S11(%arg1), %r14
ldw S12(%arg1), %r15
ldw S13(%arg1), %r16
ldw S14(%arg1), %r17
ldw PC(%arg1), %rp ;save program counter
bv 0(%rp)
.EXIT
ldw S15(%arg1), %r18
.PROCEND
.EXPORT SWITCH,ENTRY,PRIV_LEV=3,RTNVAL=GR
.EXPORT ThreadRoot,ENTRY,PRIV_LEV=3,RTNVAL=GR
#endif // PARISC
#ifdef x86
.text
.align 2
.globl ThreadRoot
.globl _ThreadRoot
/* void ThreadRoot( void )
**
** expects the following registers to be initialized:
** eax points to startup function (interrupt enable)
** edx contains inital argument to thread function
** esi points to thread function
** edi point to Thread::Finish()
*/
_ThreadRoot:
ThreadRoot:
pushl %ebp
movl %esp,%ebp
pushl InitialArg
call *StartupPC
call *InitialPC
call *WhenDonePC
# NOT REACHED
movl %ebp,%esp
popl %ebp
ret
/* void SWITCH( thread *t1, thread *t2 )
**
** on entry, stack looks like this:
** 8(esp) -> thread *t2
** 4(esp) -> thread *t1
** (esp) -> return address
**
** we push the current eax on the stack so that we can use it as
** a pointer to t1, this decrements esp by 4, so when we use it
** to reference stuff on the stack, we add 4 to the offset.
*/
.comm _eax_save,4
.globl SWITCH
.globl _SWITCH
_SWITCH:
SWITCH:
movl %eax,_eax_save # save the value of eax
movl 4(%esp),%eax # move pointer to t1 into eax
movl %ebx,_EBX(%eax) # save registers
movl %ecx,_ECX(%eax)
movl %edx,_EDX(%eax)
movl %esi,_ESI(%eax)
movl %edi,_EDI(%eax)
movl %ebp,_EBP(%eax)
movl %esp,_ESP(%eax) # save stack pointer
movl _eax_save,%ebx # get the saved value of eax
movl %ebx,_EAX(%eax) # store it
movl 0(%esp),%ebx # get return address from stack into ebx
movl %ebx,_PC(%eax) # save it into the pc storage
movl 8(%esp),%eax # move pointer to t2 into eax
movl _EAX(%eax),%ebx # get new value for eax into ebx
movl %ebx,_eax_save # save it
movl _EBX(%eax),%ebx # retore old registers
movl _ECX(%eax),%ecx
movl _EDX(%eax),%edx
movl _ESI(%eax),%esi
movl _EDI(%eax),%edi
movl _EBP(%eax),%ebp
movl _ESP(%eax),%esp # restore stack pointer
movl _PC(%eax),%eax # restore return address into eax
movl %eax,4(%esp) # copy over the ret address on the stack
movl _eax_save,%eax
ret
#endif // x86
#if defined(ApplePowerPC)
/* The AIX PowerPC code is incompatible with the assembler on MacOS X
* and Linux. So the SWITCH code was adapted for IBM 750 compatible
* processors, and ThreadRoot is modeled after the more reasonable
* looking ThreadRoot's in this file.
*
* Joshua LeVasseur <jtl@ira.uka.de>
*/
.align 2
.globl _SWITCH
_SWITCH:
stw r1, 0(r3) /* Store stack pointer. */
stmw r13, 20(r3) /* Store general purpose registers 13 - 31. */
stfd f14, 96(r3) /* Store floating point registers 14 -31. */
stfd f15, 104(r3)
stfd f16, 112(r3)
stfd f17, 120(r3)
stfd f18, 128(r3)
stfd f19, 136(r3)
stfd f20, 144(r3)
stfd f21, 152(r3)
stfd f22, 160(r3)
stfd f23, 168(r3)
stfd f24, 176(r3)
stfd f25, 184(r3)
stfd f26, 192(r3)
stfd f27, 200(r3)
stfd f28, 208(r3)
stfd f29, 216(r3)
stfd f30, 224(r3)
stfd f31, 232(r3)
mflr r0
stw r0, 244(r3) /* Spill the link register. */
mfcr r12
stw r12, 240(r3) /* Spill the condition register. */
lwz r1, 0(r4) /* Load the incoming stack pointer. */
lwz r0, 244(r4) /* Load the incoming link register. */
mtlr r0 /* Restore the link register. */
lwz r12, 240(r4) /* Load the condition register value. */
mtcrf 0xff, r12 /* Restore the condition register. */
lmw r13, 20(r4) /* Restore registers r13 - r31. */
lfd f14, 96(r4) /* Restore floating point register f14 - f31. */
lfd f15, 104(r4)
lfd f16, 112(r4)
lfd f17, 120(r4)
lfd f18, 128(r4)
lfd f19, 136(r4)
lfd f20, 144(r4)
lfd f21, 152(r4)
lfd f22, 160(r4)
lfd f23, 168(r4)
lfd f24, 176(r4)
lfd f25, 184(r4)
lfd f26, 192(r4)
lfd f27, 200(r4)
lfd f28, 208(r4)
lfd f29, 216(r4)
lfd f30, 224(r4)
lfd f31, 232(r4)
/* When a thread first starts, the following blr instruction jumps
* to ThreadRoot. ThreadRoot expects the incoming thread block
* in r4.
*/
blr /* Branch to the address held in link register. */
.align 2
.globl _ThreadRoot
_ThreadRoot:
lwz r20, 16(r4) /* StartupPCState - ThreadBegin */
lwz r21, 8(r4) /* InitialArgState - arg */
lwz r22, 4(r4) /* InitialPCState - func */
lwz r23, 12(r4) /* WhenDonePCState - ThreadFinish */
/* Call ThreadBegin function. */
mtctr r20 /* The function pointer. */
bctrl
/* Call the target function. */
mr r3, r21 /* Function arg. */
mtctr r22 /* Function pointer. */
bctrl
/* Call the ThreadFinish function. */
mtctr r23
bctrl
/* We shouldn't execute here. */
1: b 1b
#endif
#if defined(PowerPC) && !defined(ApplePowerPC)
.globl branch[ds]
.csect branch[ds]
.long .branch[PR]
.long TOC[tc0]
.long 0
.toc
T.branch: .tc .branch[tc], branch[ds]
.globl .branch[PR]
.csect .branch[PR]
l 0, 0x0(11) # load function address into r0
mtctr 0 # move r0 into counter register
l 2, 0x4(11) # move new TOC address into r2
l 11, 0x8(11) # reset function address
bctr # branch to the counter register
.globl ThreadRoot[ds]
.csect ThreadRoot[ds]
.long .ThreadRoot[PR]
.long TOC[tc0]
.long 0
.toc
T.ThreadRoot: .tc .ThreadRoot[tc], ThreadRoot[ds]
.globl .ThreadRoot[PR]
.csect .ThreadRoot[PR]
.set argarea, 32
.set linkarea, 24
.set locstckarea, 0
.set nfprs, 18
.set ngprs, 19
.set szdsa, 8*nfprs+4*ngprs+linkarea+argarea+locstckarea
mflr 0
mfcr 12
bl ._savef14
cror 0xf, 0xf, 0xf
stm 13, -8*nfprs-4*ngprs(1)
st 0, 8(1)
st 12, 4(1)
st 4, 24(1)
st 5, 28(1)
st 6, 32(1)
stu 1, -szdsa(1)
muli 11,3,1 # copy contents of register r24 to r11
bl .branch[PR] # call function branch
cror 0xf, 0xf, 0xf # no operation
ai 1,1,szdsa
lm 13, -8*nfprs-4*ngprs(1)
bl ._restf14
cror 0xf, 0xf, 0xf
l 0, 8(1)
l 12, 4(1)
mtlr 0
mtcrf 0x38, 12
l 4, 24(1)
l 5, 28(1)
l 6, 32(1)
mflr 0
mfcr 12
bl ._savef14
cror 0xf, 0xf, 0xf
stm 13, -8*nfprs-4*ngprs(1)
st 0, 8(1)
st 12, 4(1)
st 6, 24(1)
stu 1, -szdsa(1)
muli 3, 4,1 # load user function parameter r22 to r3
muli 11,5,1 # copy contents of register r21 to r11
bl .branch[PR] # call function branch
cror 0xf, 0xf, 0xf # no operation
ai 1,1,szdsa
lm 13, -8*nfprs-4*ngprs(1)
bl ._restf14
cror 0xf, 0xf, 0xf
l 0, 8(1)
l 12, 4(1)
mtlr 0
mtcrf 0x38, 12
l 6, 24(1)
muli 11,6,1 # copy contents of register r23 to r11
bl .branch[PR] # call function branch
cror 0xf, 0xf, 0xf # no operation
brl # the programme should not return here.
.extern ._savef14
.extern ._restf14
.globl SWITCH[ds]
.csect SWITCH[ds]
.long .SWITCH[PR]
.long TOC[tc0]
.long 0
.toc
T.SWITCH: .tc .SWITCH[tc], SWITCH[ds]
.globl .SWITCH[PR]
.csect .SWITCH[PR]
st 1, 0(3) # store stack pointer
stm 13, 20(3) # store general purpose registers (13 -31)
stfd 14, 96(3) # store floating point registers (14 -31)
stfd 15, 104(3) # there is no single instruction to do for
stfd 16, 112(3) # floating point registers. so do one by one
stfd 17, 120(3)
stfd 18, 128(3)
stfd 19, 136(3)
stfd 20, 144(3)
stfd 21, 152(3)
stfd 22, 160(3)
stfd 23, 168(3)
stfd 24, 176(3)
stfd 25, 184(3)
stfd 26, 192(3)
stfd 27, 200(3)
stfd 28, 208(3)
stfd 29, 216(3)
stfd 30, 224(3)
stfd 31, 232(3)
mflr 0 # move link register value to register 0
st 0, 244(3) # store link register value
mfcr 12 # move condition register to register 12
st 12, 240(3) # store condition register value
l 1, 0(4) # load stack pointer
l 0, 244(4) # load link register value
mtlr 0
l 12, 240(4) # load condition register value
mtcrf 0x38, 12
lm 13, 20(4) # load into general purpose registers (13 -31)
lfd 14, 96(4) # load into floating point registers (14 -31)
lfd 15, 104(4) # there is no single instruction for
lfd 16, 112(4) # loading into more than one floating point
lfd 17, 120(4) # registers. so do one by one.
lfd 18, 128(4)
lfd 19, 136(4)
lfd 20, 144(4)
lfd 21, 152(4)
lfd 22, 160(4)
lfd 23, 168(4)
lfd 24, 176(4)
lfd 25, 184(4)
lfd 26, 192(4)
lfd 27, 200(4)
lfd 28, 208(4)
lfd 29, 216(4)
lfd 30, 224(4)
lfd 31, 232(4)
l 3, 16(4)
l 5, 4(4)
l 6, 12(4)
l 4, 8(4)
brl # branch to the address held in link register.
#endif // PowerPC
#ifdef ALPHA
/*
* Porting to Alpha was done by Shuichi Oikawa (shui@sfc.keio.ac.jp).
*/
/*
* Symbolic register names and register saving rules
*
* Legend:
* T Saved by caller (Temporaries)
* S Saved by callee (call-Safe registers)
*/
#define v0 $0 /* (T) return value */
#define t0 $1 /* (T) temporary registers */
#define s0 $9 /* (S) call-safe registers */
#define s1 $10
#define s2 $11
#define s3 $12
#define s4 $13
#define s5 $14
#define s6 $15
#define a0 $16 /* (T) argument registers */
#define a1 $17
#define ai $25 /* (T) argument information */
#define ra $26 /* (T) return address */
#define pv $27 /* (T) procedure value */
#define gp $29 /* (T) (local) data pointer */
#define sp $30 /* (S) stack pointer */
#define zero $31 /* wired zero */
.set noreorder # unless overridden
.align 3
.text
.globl ThreadRoot
.ent ThreadRoot,0
ThreadRoot:
.frame sp,0,ra
ldgp gp,0(pv)
mov zero,s6 # Clearing the frame pointer here
# makes gdb backtraces of thread stacks
# end here (I hope!)
mov StartupPC,pv
jsr ra,(pv) # call startup procedure
ldgp gp,0(ra)
mov InitialArg,a0
mov InitialPC,pv
jsr ra,(pv) # call main procedure
ldgp gp,0(ra)
mov WhenDonePC,pv
jsr ra,(pv) # when done, call clean up procedure
ldgp gp,0(ra)
.end ThreadRoot # NEVER REACHED
/* a0 -- pointer to old Thread *
* a1 -- pointer to new Thread */
.globl SWITCH
.ent SWITCH,0
SWITCH:
.frame sp,0,ra
ldgp gp,0(pv)
stq ra, PC(a0) # save return address
stq gp, GP(a0)
stq sp, SP(a0) # save new stack pointer
stq s0, S0(a0) # save all the callee-save registers
stq s1, S1(a0)
stq s2, S2(a0)
stq s3, S3(a0)
stq s4, S4(a0)
stq s5, S5(a0)
stq s6, S6(a0) # save frame pointer
ldq ra, PC(a1) # load the return address
ldq gp, GP(a1)
ldq sp, SP(a1) # load the new stack pointer
ldq s0, S0(a1) # load the callee-save registers
ldq s1, S1(a1)
ldq s2, S2(a1)
ldq s3, S3(a1)
ldq s4, S4(a1)
ldq s5, S5(a1)
ldq s6, S6(a1)
mov ra,pv
ret zero,(ra)
.end SWITCH
#endif // ALPHA