version 1.4, 2002/12/17 20:49:07 |
version 1.4.2.1, 2002/12/18 05:00:59 |
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/*****************************************************************************/ |
/*****************************************************************************/ |
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.globl _C_LABEL(sched_whichqs),_C_LABEL(sched_qs) |
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.globl _C_LABEL(uvmexp),_C_LABEL(panic) |
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#ifdef DIAGNOSTIC |
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NENTRY(switch_error) |
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pushl $1f |
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call _C_LABEL(panic) |
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/* NOTREACHED */ |
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1: .asciz "cpu_switch" |
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#endif /* DIAGNOSTIC */ |
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/* |
/* |
* void cpu_switch(struct proc *) |
* void cpu_idle(void) |
* Find a runnable process and switch to it. Wait if necessary. If the new |
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* process is the same as the old one, we short-circuit the context save and |
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* restore. |
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* |
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* Note that the stack frame layout is known to "struct switchframe" |
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* in <machine/frame.h> and to the code in cpu_fork() which initializes |
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* it for a new process. |
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*/ |
*/ |
ENTRY(cpu_switch) |
ENTRY(cpu_idle) |
pushl %ebx |
pushl %ebx |
pushl %esi |
pushl %esi |
pushl %edi |
pushl %edi |
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#ifdef DEBUG |
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cmpl $IPL_SCHED,CPUVAR(ILEVEL) |
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jae 1f |
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pushl 2f |
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call _C_LABEL(panic) |
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/* NOTREACHED */ |
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2: .asciz "not splhigh() in cpu_switch!" |
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1: |
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#endif /* DEBUG */ |
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movl CPUVAR(CURPROC),%esi |
movl CPUVAR(CURPROC),%esi |
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/* |
/* |
* Clear curproc so that we don't accumulate system time while idle. |
* Clear curproc so that we don't accumulate system time while idle. |
* This also insures that schedcpu() will move the old process to |
* This also insures that schedcpu() will move the old process to |
Line 1694 ENTRY(cpu_switch) |
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Line 1665 ENTRY(cpu_switch) |
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* userret()). |
* userret()). |
*/ |
*/ |
movl $0,CPUVAR(CURPROC) |
movl $0,CPUVAR(CURPROC) |
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/* |
/* |
* First phase: find new process. |
* Save old context. |
* |
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* Registers: |
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* %eax - queue head, scratch, then zero |
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* %ebx - queue number |
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* %ecx - cached value of whichqs |
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* %edx - next process in queue |
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* %esi - old process |
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* %edi - new process |
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*/ |
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/* Look for new process. */ |
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cli # splhigh doesn't do a cli |
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movl _C_LABEL(sched_whichqs),%ecx |
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bsfl %ecx,%ebx # find a full q |
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jnz switch_dequeue |
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/* |
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* idling: save old context. |
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* |
* |
* Registers: |
* Registers: |
* %eax, %ecx - scratch |
* %eax, %ecx - scratch |
Line 1725 ENTRY(cpu_switch) |
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Line 1679 ENTRY(cpu_switch) |
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call _C_LABEL(pmap_deactivate) # pmap_deactivate(oldproc) |
call _C_LABEL(pmap_deactivate) # pmap_deactivate(oldproc) |
addl $4,%esp |
addl $4,%esp |
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movl P_ADDR(%esi),%esi |
movl P_ADDR(%esi),%edi |
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/* Save stack pointers. */ |
/* Save stack pointers. */ |
movl %esp,PCB_ESP(%esi) |
movl %esp,PCB_ESP(%edi) |
movl %ebp,PCB_EBP(%esi) |
movl %ebp,PCB_EBP(%edi) |
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/* Find idle PCB for this CPU */ |
/* Find idle PCB for this CPU */ |
#ifndef MULTIPROCESSOR |
#ifndef MULTIPROCESSOR |
Line 1749 ENTRY(cpu_switch) |
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Line 1703 ENTRY(cpu_switch) |
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movl PCB_ESP(%edi),%esp |
movl PCB_ESP(%edi),%esp |
movl PCB_EBP(%edi),%ebp |
movl PCB_EBP(%edi),%ebp |
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/* Switch address space. */ |
/* Switch address space. */ |
movl PCB_CR3(%edi),%ecx |
movl PCB_CR3(%edi),%ecx |
movl %ecx,%cr3 |
movl %ecx,%cr3 |
Line 1772 ENTRY(cpu_switch) |
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Line 1725 ENTRY(cpu_switch) |
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/* Record new pcb. */ |
/* Record new pcb. */ |
SET_CURPCB(%edi) |
SET_CURPCB(%edi) |
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xorl %esi,%esi |
pushl %esi |
sti |
sti |
idle_unlock: |
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1: |
#if defined(MULTIPROCESSOR) || defined(LOCKDEBUG) |
#if defined(MULTIPROCESSOR) || defined(LOCKDEBUG) |
call _C_LABEL(sched_unlock_idle) |
call _C_LABEL(sched_unlock_idle) |
#endif |
#endif |
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pushl $IPL_NONE # spl0() |
pushl $IPL_NONE # spl0() |
call _C_LABEL(Xspllower) # process pending interrupts |
call _C_LABEL(Xspllower) # process pending interrupts |
addl $4,%esp |
addl $4,%esp |
jmp idle_start |
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idle_zero: |
NENTRY(mpidle) |
sti |
idle_start: |
call _C_LABEL(uvm_pageidlezero) |
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cli |
cli |
cmpl $0,_C_LABEL(sched_whichqs) |
cmpl $0,_C_LABEL(sched_whichqs) |
jnz idle_exit |
jnz idle_exit |
idle_loop: |
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/* Try to zero some pages. */ |
/* |
movl _C_LABEL(uvm)+UVM_PAGE_IDLE_ZERO,%ecx |
* Try to zero some pages. |
testl %ecx,%ecx |
*/ |
jnz idle_zero |
movl _C_LABEL(uvm)+UVM_PAGE_IDLE_ZERO,%ecx |
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testl %ecx,%ecx |
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jnz idle_zero |
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sti |
sti |
hlt |
hlt |
NENTRY(mpidle) |
jmp idle_start |
idle_start: |
idle_zero: |
cli |
sti |
cmpl $0,_C_LABEL(sched_whichqs) |
call _C_LABEL(uvm_pageidlezero) |
jz idle_loop |
jmp idle_start |
idle_exit: |
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idle_exit: |
movl $IPL_HIGH,CPUVAR(ILEVEL) # splhigh |
movl $IPL_HIGH,CPUVAR(ILEVEL) # splhigh |
#if defined(MULTIPROCESSOR) || defined(LOCKDEBUG) |
#if defined(MULTIPROCESSOR) || defined(LOCKDEBUG) |
call _C_LABEL(sched_lock_idle) |
call _C_LABEL(sched_lock_idle) |
#endif |
#endif |
movl _C_LABEL(sched_whichqs),%ecx |
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bsfl %ecx,%ebx |
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jz idle_unlock |
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switch_dequeue: |
popl %edi |
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movl %edi,CPUVAR(CURPROC) |
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movl P_ADDR(%edi),%esi |
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/* Restore stack pointers. */ |
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movl PCB_ESP(%esi),%esp |
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movl PCB_EBP(%esi),%ebp |
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#ifdef MULTIPROCESSOR |
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movl CPUVAR(GDT),%eax |
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#else |
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/* Load TSS info. */ |
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movl _C_LABEL(gdt),%eax |
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#endif |
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movl P_MD_TSS_SEL(%edi),%edx |
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/* Switch TSS. Reset "task busy" flag before loading. */ |
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andl $~0x0200,4(%eax,%edx, 1) |
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ltr %dx |
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pushl %edi |
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call _C_LABEL(pmap_activate) # pmap_activate(p) |
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addl $4,%esp |
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/* Restore cr0 (including FPU state). */ |
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movl PCB_CR0(%esi),%ecx |
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#ifdef MULTIPROCESSOR |
/* |
/* |
* we're running at splhigh(), but it's otherwise okay to take |
* If our floating point registers are on a different cpu, |
* interrupts here. |
* clear CR0_TS so we'll trap rather than reuse bogus state. |
*/ |
*/ |
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movl PCB_FPCPU(%esi),%ebx |
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cmpl CPUVAR(SELF),%ebx |
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jz 1f |
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orl $CR0_TS,%ecx |
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1: |
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#endif |
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movl %ecx,%cr0 |
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/* Record new pcb. */ |
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SET_CURPCB(%esi) |
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/* Interrupts are okay again. */ |
sti |
sti |
leal _C_LABEL(sched_qs)(,%ebx,8),%eax # select q |
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cpu_idle_exit: |
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popl %edi |
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popl %esi |
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popl %ebx |
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ret |
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movl P_FORW(%eax),%edi # unlink from front of process q |
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#ifdef DIAGNOSTIC |
#ifdef DIAGNOSTIC |
cmpl %edi,%eax # linked to self (i.e. nothing queued)? |
NENTRY(switch_error) |
je _C_LABEL(switch_error) # not possible |
pushl $1f |
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call _C_LABEL(panic) |
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/* NOTREACHED */ |
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1: .asciz "cpu_switch" |
#endif /* DIAGNOSTIC */ |
#endif /* DIAGNOSTIC */ |
movl P_FORW(%edi),%edx |
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movl %edx,P_FORW(%eax) |
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movl %eax,P_BACK(%edx) |
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cmpl %edx,%eax # q empty? |
/* |
jne 3f |
* void cpu_switch(struct proc *oldp, struct proc *newp) |
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* Find a runnable process and switch to it. Wait if necessary. If the new |
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* process is the same as the old one, we short-circuit the context save and |
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* restore. |
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* |
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* Note that the stack frame layout is known to "struct switchframe" |
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* in <machine/frame.h> and to the code in cpu_fork() which initializes |
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* it for a new process. |
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*/ |
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ENTRY(cpu_switch) |
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pushl %ebx |
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pushl %esi |
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pushl %edi |
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btrl %ebx,%ecx # yes, clear to indicate empty |
movl 20(%esp),%edi |
movl %ecx,_C_LABEL(sched_whichqs) # update q status |
movl 16(%esp),%esi |
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3: /* We just did it. */ |
#ifdef DEBUG |
xorl %eax,%eax |
cmpl $IPL_SCHED,CPUVAR(ILEVEL) |
CLEAR_RESCHED(%eax) |
jae 1f |
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pushl 2f |
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call _C_LABEL(panic) |
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/* NOTREACHED */ |
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2: .asciz "not splhigh() in cpu_switch!" |
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1: |
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#endif /* DEBUG */ |
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sw1: |
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#ifdef DIAGNOSTIC |
#ifdef DIAGNOSTIC |
cmpl %eax,P_WCHAN(%edi) # Waiting for something? |
cmpl $0,P_WCHAN(%edi) # Waiting for something? |
jne _C_LABEL(switch_error) # Yes; shouldn't be queued. |
jne _C_LABEL(switch_error) # Yes; shouldn't be queued. |
cmpb $SRUN,P_STAT(%edi) # In run state? |
cmpb $SRUN,P_STAT(%edi) # In run state? |
jne _C_LABEL(switch_error) # No; shouldn't be queued. |
jne _C_LABEL(switch_error) # No; shouldn't be queued. |
#endif /* DIAGNOSTIC */ |
#endif /* DIAGNOSTIC */ |
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/* Isolate process. XXX Is this necessary? */ |
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movl %eax,P_BACK(%edi) |
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/* Record new process. */ |
/* Record new process. */ |
movb $SONPROC,P_STAT(%edi) # p->p_stat = SONPROC |
movb $SONPROC,P_STAT(%edi) # p->p_stat = SONPROC |
SET_CURPROC(%edi,%ecx) |
SET_CURPROC(%edi,%ecx) |
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/* Skip context switch if same process. */ |
/* We just did it. */ |
cmpl %edi,%esi |
xorl %eax,%eax |
je switch_return |
CLEAR_RESCHED(%eax) |
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/* If old process exited, don't bother. */ |
/* If old process exited, don't bother. */ |
testl %esi,%esi |
testl %esi,%esi |
jz switch_exited |
jz 1f |
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/* |
/* |
* Second phase: save old context. |
* Save old context. |
* |
* |
* Registers: |
* Registers: |
* %eax, %ecx - scratch |
* %eax, %ecx - scratch |
Line 1878 switch_dequeue: |
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Line 1894 switch_dequeue: |
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movl %esp,PCB_ESP(%esi) |
movl %esp,PCB_ESP(%esi) |
movl %ebp,PCB_EBP(%esi) |
movl %ebp,PCB_EBP(%esi) |
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switch_exited: |
1: |
/* |
/* |
* Third phase: restore saved context. |
* Restore saved context. |
* |
* |
* Registers: |
* Registers: |
* %eax, %ebx, %ecx, %edx - scratch |
* %eax, %ebx, %ecx, %edx - scratch |
Line 1942 switch_restored: |
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Line 1958 switch_restored: |
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/* Interrupts are okay again. */ |
/* Interrupts are okay again. */ |
sti |
sti |
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/* |
/* |
* Check for restartable atomic sequences (RAS) |
* Check for restartable atomic sequences (RAS) |
*/ |
*/ |
movl CPUVAR(CURPROC),%edi |
movl CPUVAR(CURPROC),%edi |
cmpl $0,P_NRAS(%edi) |
cmpl $0,P_NRAS(%edi) |
je 1f |
je 1f |
Line 1959 switch_restored: |
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Line 1975 switch_restored: |
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movl %eax,TF_EIP(%ebx) |
movl %eax,TF_EIP(%ebx) |
1: |
1: |
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switch_return: |
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#if defined(MULTIPROCESSOR) || defined(LOCKDEBUG) |
#if defined(MULTIPROCESSOR) || defined(LOCKDEBUG) |
call _C_LABEL(sched_unlock_idle) |
call _C_LABEL(sched_unlock_idle) |
#endif |
#endif |
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addl $4,%esp |
addl $4,%esp |
movl $IPL_HIGH,CPUVAR(ILEVEL) # splhigh() |
movl $IPL_HIGH,CPUVAR(ILEVEL) # splhigh() |
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movl %edi,%eax # return (p); |
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popl %edi |
popl %edi |
popl %esi |
popl %esi |
popl %ebx |
popl %ebx |
Line 2042 ENTRY(switch_exit) |
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Line 2056 ENTRY(switch_exit) |
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call _C_LABEL(exit2) |
call _C_LABEL(exit2) |
addl $4,%esp |
addl $4,%esp |
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#if defined(MULTIPROCESSOR) || defined(LOCKDEBUG) |
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call _C_LABEL(sched_lock_idle) |
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#endif |
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call _C_LABEL(chooseproc) |
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movl %eax,%edi |
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/* Jump into cpu_switch() with the right state. */ |
/* Jump into cpu_switch() with the right state. */ |
xorl %esi,%esi |
xorl %esi,%esi |
movl %esi,CPUVAR(CURPROC) |
movl %esi,CPUVAR(CURPROC) |
jmp idle_start |
jmp sw1 |
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/* |
/* |
* void savectx(struct pcb *pcb); |
* void savectx(struct pcb *pcb); |