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Diff for /src/sys/arch/i386/i386/locore.S between version 1.45.2.8 and 1.46

version 1.45.2.8, 2007/04/04 22:33:28 version 1.46, 2007/02/17 22:31:37
Line 1 
Line 1 
 /*      $NetBSD$        */  /*      $NetBSD$        */
   
 /*-  /*-
  * Copyright (c) 1998, 2000, 2004, 2006, 2007 The NetBSD Foundation, Inc.   * Copyright (c) 1998, 2000, 2004 The NetBSD Foundation, Inc.
  * All rights reserved.   * All rights reserved.
  *   *
  * This code is derived from software contributed to The NetBSD Foundation   * This code is derived from software contributed to The NetBSD Foundation
Line 70 
Line 70 
  *      @(#)locore.s    7.3 (Berkeley) 5/13/91   *      @(#)locore.s    7.3 (Berkeley) 5/13/91
  */   */
   
   #include "opt_compat_netbsd.h"
 #include "opt_compat_oldboot.h"  #include "opt_compat_oldboot.h"
 #include "opt_cputype.h"  #include "opt_cputype.h"
 #include "opt_ddb.h"  #include "opt_ddb.h"
   #include "opt_ipkdb.h"
   #include "opt_lockdebug.h"
   #include "opt_multiprocessor.h"
 #include "opt_realmem.h"  #include "opt_realmem.h"
   #include "opt_user_ldt.h"
 #include "opt_vm86.h"  #include "opt_vm86.h"
   
 #include "npx.h"  #include "npx.h"
Line 89 
Line 94 
 #include <machine/segments.h>  #include <machine/segments.h>
 #include <machine/specialreg.h>  #include <machine/specialreg.h>
 #include <machine/trap.h>  #include <machine/trap.h>
   
   #if NLAPIC > 0
 #include <machine/i82489reg.h>  #include <machine/i82489reg.h>
   #endif
   
 #include <machine/multiboot.h>  #include <machine/multiboot.h>
   
   /* LINTSTUB: include <sys/types.h> */
   /* LINTSTUB: include <machine/cpu.h> */
   /* LINTSTUB: include <sys/systm.h> */
   
 #include <machine/asm.h>  #include <machine/asm.h>
 #include <machine/frameasm.h>  
 #include <machine/i82489reg.h>  #if defined(MULTIPROCESSOR)
   
   #define SET_CURLWP(lwp,cpu)                             \
           movl    CPUVAR(SELF),cpu                ;       \
           movl    lwp,CPUVAR(CURLWP)      ;       \
           movl    cpu,L_CPU(lwp)
   
   #else
   
   #define SET_CURLWP(lwp,tcpu)            movl    lwp,CPUVAR(CURLWP)
   #define GET_CURLWP(reg)                 movl    CPUVAR(CURLWP),reg
   
   #endif
   
   #define SET_CURPCB(reg)                 movl    reg,CPUVAR(CURPCB)
   
   #define CLEAR_RESCHED(reg)              movl    reg,CPUVAR(RESCHED)
   
 /* XXX temporary kluge; these should not be here */  /* XXX temporary kluge; these should not be here */
 /* Get definitions for IOM_BEGIN, IOM_END, and IOM_SIZE */  /* Get definitions for IOM_BEGIN, IOM_END, and IOM_SIZE */
 #include <dev/isa/isareg.h>  #include <dev/isa/isareg.h>
   
   
   /* Disallow old names for REALBASEMEM */
   #ifdef BIOSBASEMEM
   #error BIOSBASEMEM option deprecated; use REALBASEMEM only if memory size reported by latest boot block is incorrect
   #endif
   
   /* Disallow old names for REALEXTMEM */
   #ifdef EXTMEM_SIZE
   #error EXTMEM_SIZE option deprecated; use REALEXTMEM only if memory size reported by latest boot block is incorrect
   #endif
   #ifdef BIOSEXTMEM
   #error BIOSEXTMEM option deprecated; use REALEXTMEM only if memory size reported by latest boot block is incorrect
   #endif
   
   #include <machine/frameasm.h>
   
   
   #ifdef MULTIPROCESSOR
   #include <machine/i82489reg.h>
   #endif
   
 /*  /*
  * Initialization   * Initialization
  */   */
Line 109 
Line 160 
         .globl  _C_LABEL(atdevbase)          .globl  _C_LABEL(atdevbase)
         .globl  _C_LABEL(proc0uarea),_C_LABEL(PDPpaddr)          .globl  _C_LABEL(proc0uarea),_C_LABEL(PDPpaddr)
         .globl  _C_LABEL(gdt)          .globl  _C_LABEL(gdt)
   #ifdef I586_CPU
         .globl  _C_LABEL(idt)          .globl  _C_LABEL(idt)
   #endif
         .globl  _C_LABEL(lapic_tpr)          .globl  _C_LABEL(lapic_tpr)
   
 #if NLAPIC > 0  #if NLAPIC > 0
Line 135  _C_LABEL(lapic_tpr):
Line 188  _C_LABEL(lapic_tpr):
         .long 0          .long 0
 #endif  #endif
   
 _C_LABEL(cpu):          .long   0       # are we 80486, Pentium, or..  
   _C_LABEL(cpu):          .long   0       # are we 386, 386sx, or 486,
                                           #   or Pentium, or..
 _C_LABEL(atdevbase):    .long   0       # location of start of iomem in virtual  _C_LABEL(atdevbase):    .long   0       # location of start of iomem in virtual
 _C_LABEL(proc0uarea):   .long   0  _C_LABEL(proc0uarea):   .long   0
 _C_LABEL(PDPpaddr):     .long   0       # paddr of PDP, for libkvm  _C_LABEL(PDPpaddr):     .long   0       # paddr of PDP, for libkvm
Line 587  begin:
Line 642  begin:
         call    _C_LABEL(main)          call    _C_LABEL(main)
   
 /*  /*
  * void lwp_trampoline(void);   * void proc_trampoline(void);
  *  
  * This is a trampoline function pushed onto the stack of a newly created   * This is a trampoline function pushed onto the stack of a newly created
  * process in order to do some additional setup.  The trampoline is entered by   * process in order to do some additional setup.  The trampoline is entered by
  * cpu_switch()ing to the process, so we abuse the callee-saved registers used   * cpu_switch()ing to the process, so we abuse the callee-saved registers used
  * by cpu_switch() to store the information about the stub to call.   * by cpu_switch() to store the information about the stub to call.
  * NOTE: This function does not have a normal calling sequence!   * NOTE: This function does not have a normal calling sequence!
  */   */
 NENTRY(lwp_trampoline)  /* LINTSTUB: Func: void proc_trampoline(void) */
         pushl   %ebp  NENTRY(proc_trampoline)
         xorl    %ebp,%ebp  #ifdef MULTIPROCESSOR
         pushl   %eax          call    _C_LABEL(proc_trampoline_mp)
         call    _C_LABEL(lwp_startup)  #endif
         addl    $8,%esp          movl    $IPL_NONE,CPUVAR(ILEVEL)
         pushl   %ebx          pushl   %ebx
         call    *%esi          call    *%esi
         addl    $4,%esp          addl    $4,%esp
Line 608  NENTRY(lwp_trampoline)
Line 662  NENTRY(lwp_trampoline)
         INTRFASTEXIT          INTRFASTEXIT
         /* NOTREACHED */          /* NOTREACHED */
   
   /*****************************************************************************/
   #ifdef COMPAT_16
 /*  /*
  * sigcode()   * Signal trampoline; copied to top of user stack.
  *  
  * Signal trampoline; copied to top of user stack.  Used only for  
  * compatibility with old releases of NetBSD.  
  */   */
   /* LINTSTUB: Var: char sigcode[1], esigcode[1]; */
 NENTRY(sigcode)  NENTRY(sigcode)
         /*          /*
          * Handler has returned here as if we called it.  The sigcontext           * Handler has returned here as if we called it.  The sigcontext
Line 628  NENTRY(sigcode)
Line 682  NENTRY(sigcode)
         int     $0x80                   # exit if sigreturn fails          int     $0x80                   # exit if sigreturn fails
         .globl  _C_LABEL(esigcode)          .globl  _C_LABEL(esigcode)
 _C_LABEL(esigcode):  _C_LABEL(esigcode):
   #endif
   
   /*****************************************************************************/
   
   /*
    * The following is i386-specific nonsense.
    */
   
 /*  /*
  * void lgdt(struct region_descriptor *rdp);   * void lgdt(struct region_descriptor *rdp);
  *  
  * Load a new GDT pointer (and do any necessary cleanup).   * Load a new GDT pointer (and do any necessary cleanup).
  * XXX It's somewhat questionable whether reloading all the segment registers   * XXX It's somewhat questionable whether reloading all the segment registers
  * is necessary, since the actual descriptor data is not changed except by   * is necessary, since the actual descriptor data is not changed except by
  * process creation and exit, both of which clean up via task switches.  OTOH,   * process creation and exit, both of which clean up via task switches.  OTOH,
  * this only happens at run time when the GDT is resized.   * this only happens at run time when the GDT is resized.
  */   */
   /* LINTSTUB: Func: void lgdt(struct region_descriptor *rdp) */
 NENTRY(lgdt)  NENTRY(lgdt)
         /* Reload the descriptor table. */          /* Reload the descriptor table. */
         movl    4(%esp),%eax          movl    4(%esp),%eax
Line 659  NENTRY(lgdt)
Line 720  NENTRY(lgdt)
         pushl   %eax          pushl   %eax
         lret          lret
   
 /*  
  * void x86_flush()  
  *  
  * Flush instruction pipelines by doing an intersegment (far) return.  
  */  
 NENTRY(x86_flush)  NENTRY(x86_flush)
           /* Reload code selector by doing intersegment return. */
         popl    %eax          popl    %eax
         pushl   $GSEL(GCODE_SEL, SEL_KPL)          pushl   $GSEL(GCODE_SEL, SEL_KPL)
         pushl   %eax          pushl   %eax
         lret          lret
   
   /*****************************************************************************/
   
 /*  /*
  * int setjmp(label_t *)   * These functions are primarily used by DDB.
  *  
  * Used primarily by DDB.  
  */   */
   
   /* LINTSTUB: Func: int setjmp (label_t *l) */
 ENTRY(setjmp)  ENTRY(setjmp)
         movl    4(%esp),%eax          movl    4(%esp),%eax
         movl    %ebx,(%eax)             # save ebx          movl    %ebx,(%eax)             # save ebx
Line 684  ENTRY(setjmp)
Line 743  ENTRY(setjmp)
         movl    %edi,16(%eax)           # save edi          movl    %edi,16(%eax)           # save edi
         movl    (%esp),%edx             # get rta          movl    (%esp),%edx             # get rta
         movl    %edx,20(%eax)           # save eip          movl    %edx,20(%eax)           # save eip
         xorl    %eax,%eax               # return 0          xorl    %eax,%eax               # return (0);
         ret          ret
   
 /*  /* LINTSTUB: Func: void longjmp (label_t *l) */
  * int longjmp(label_t *)  
  *  
  * Used primarily by DDB.  
  */  
 ENTRY(longjmp)  ENTRY(longjmp)
         movl    4(%esp),%eax          movl    4(%esp),%eax
         movl    (%eax),%ebx             # restore ebx          movl    (%eax),%ebx             # restore ebx
Line 701  ENTRY(longjmp)
Line 756  ENTRY(longjmp)
         movl    16(%eax),%edi           # restore edi          movl    16(%eax),%edi           # restore edi
         movl    20(%eax),%edx           # get rta          movl    20(%eax),%edx           # get rta
         movl    %edx,(%esp)             # put in return frame          movl    %edx,(%esp)             # put in return frame
         movl    $1,%eax                 # return 1          xorl    %eax,%eax               # return (1);
           incl    %eax
         ret          ret
   
   /*****************************************************************************/
   
           .globl  _C_LABEL(sched_whichqs),_C_LABEL(sched_qs)
           .globl  _C_LABEL(uvmexp),_C_LABEL(panic)
   
   #ifdef DIAGNOSTIC
   NENTRY(switch_error)
           pushl   $1f
           call    _C_LABEL(panic)
           /* NOTREACHED */
   1:      .asciz  "cpu_switch"
   #endif /* DIAGNOSTIC */
   
 /*  /*
  * struct lwp *cpu_switchto(struct lwp *oldlwp, struct newlwp)   * void cpu_switch(struct lwp *)
    * Find a runnable lwp and switch to it.  Wait if necessary.  If the new
    * lwp is the same as the old one, we short-circuit the context save and
    * restore.
  *   *
  *      1. if (oldlwp != NULL), save its context.   * Note that the stack frame layout is known to "struct switchframe"
  *      2. then, restore context of newlwp.   * in <machine/frame.h> and to the code in cpu_fork() which initializes
  *  
  * Note that the stack frame layout is known to "struct switchframe" in  
  * <machine/frame.h> and to the code in cpu_lwp_fork() which initializes  
  * it for a new lwp.   * it for a new lwp.
  */   */
 ENTRY(cpu_switchto)  ENTRY(cpu_switch)
         pushl   %ebx          pushl   %ebx
         pushl   %esi          pushl   %esi
         pushl   %edi          pushl   %edi
   
         movl    16(%esp),%esi           # oldlwp  #ifdef DEBUG
         movl    20(%esp),%edi           # newlwp          cmpl    $IPL_SCHED,CPUVAR(ILEVEL)
         testl   %esi,%esi          jae     1f
         jz      1f          pushl   $2f
           call    _C_LABEL(panic)
           /* NOTREACHED */
   2:      .asciz  "not splsched() in cpu_switch!"
   1:
   #endif /* DEBUG */
   
           movl    16(%esp),%esi           # current
   
           /*
            * Clear curlwp so that we don't accumulate system time while idle.
            * This also insures that schedcpu() will move the old lwp to
            * the correct queue if it happens to get called from the spllower()
            * below and changes the priority.  (See corresponding comment in
            * userret()).
            */
           movl    $0,CPUVAR(CURLWP)
           /*
            * First phase: find new lwp.
            *
            * Registers:
            *   %eax - queue head, scratch, then zero
            *   %ebx - queue number
            *   %ecx - cached value of whichqs
            *   %edx - next lwp in queue
            *   %esi - old lwp
            *   %edi - new lwp
            */
   
           /* Look for new lwp. */
           cli                             # splhigh doesn't do a cli
           movl    _C_LABEL(sched_whichqs),%ecx
           bsfl    %ecx,%ebx               # find a full q
           jnz     switch_dequeue
   
           /*
            * idling:      save old context.
            *
            * Registers:
            *   %eax, %ecx - scratch
            *   %esi - old lwp, then old pcb
            *   %edi - idle pcb
            */
   
           pushl   %esi
           call    _C_LABEL(pmap_deactivate2)      # pmap_deactivate(oldproc)
           addl    $4,%esp
   
         /* Save old context. */          movl    L_ADDR(%esi),%esi
         movl    L_ADDR(%esi),%eax  
         movl    %esp,PCB_ESP(%eax)          /* Save stack pointers. */
         movl    %ebp,PCB_EBP(%eax)          movl    %esp,PCB_ESP(%esi)
           movl    %ebp,PCB_EBP(%esi)
         /* Switch to newlwp's stack. */  
 1:      movl    L_ADDR(%edi),%ebx          /* Find idle PCB for this CPU */
         movl    PCB_EBP(%ebx),%ebp  #ifndef MULTIPROCESSOR
         movl    PCB_ESP(%ebx),%esp          movl    $_C_LABEL(lwp0),%ebx
           movl    L_ADDR(%ebx),%edi
           movl    L_MD_TSS_SEL(%ebx),%edx
   #else
           movl    CPUVAR(IDLE_PCB),%edi
           movl    CPUVAR(IDLE_TSS_SEL),%edx
   #endif
           movl    $0,CPUVAR(CURLWP)               /* In case we fault... */
   
         /* Switch TSS.  Reset "task busy" flag before loading. */          /* Restore the idle context (avoid interrupts) */
           cli
   
           /* Restore stack pointers. */
           movl    PCB_ESP(%edi),%esp
           movl    PCB_EBP(%edi),%ebp
   
           /* Switch TSS. Reset "task busy" flag before loading. */
         movl    %cr3,%eax          movl    %cr3,%eax
         movl    %eax,PCB_CR3(%ebx)      # for TSS gates          movl    %eax,PCB_CR3(%edi)
   #ifdef MULTIPROCESSOR
         movl    CPUVAR(GDT),%eax          movl    CPUVAR(GDT),%eax
         movl    L_MD_TSS_SEL(%edi),%edx  #else
         andl    $~0x0200,4(%eax,%edx, 1)          movl    _C_LABEL(gdt),%eax
   #endif
           andl    $~0x0200,4-SEL_KPL(%eax,%edx,1)
         ltr     %dx          ltr     %dx
   
         /* Set curlwp. */          /* We're always in the kernel, so we don't need the LDT. */
         movl    %edi,CPUVAR(CURLWP)  
           /* Restore cr0 (including FPU state). */
           movl    PCB_CR0(%edi),%ecx
           movl    %ecx,%cr0
   
           /* Record new pcb. */
           SET_CURPCB(%edi)
   
           xorl    %esi,%esi
           sti
   idle_unlock:
           call    _C_LABEL(sched_unlock_idle)
           /* Interrupts are okay again. */
           pushl   $IPL_NONE               # spl0()
           call    _C_LABEL(spllower)      # process pending interrupts
           addl    $4,%esp
           jmp     idle_start
   idle_zero:
           sti
           call    _C_LABEL(uvm_pageidlezero)
           cli
           cmpl    $0,_C_LABEL(sched_whichqs)
           jnz     idle_exit
   idle_loop:
           /* Try to zero some pages. */
           movl    _C_LABEL(uvm)+UVM_PAGE_IDLE_ZERO,%ecx
           testl   %ecx,%ecx
           jnz     idle_zero
           sti
           hlt
   NENTRY(mpidle)
   idle_start:
           cli
           cmpl    $0,_C_LABEL(sched_whichqs)
           jz      idle_loop
   idle_exit:
           movl    $IPL_HIGH,CPUVAR(ILEVEL)                # splhigh
           sti
           call    _C_LABEL(sched_lock_idle)
           movl    _C_LABEL(sched_whichqs),%ecx
           bsfl    %ecx,%ebx
           jz      idle_unlock
   
   switch_dequeue:
           /*
            * we're running at splhigh(), but it's otherwise okay to take
            * interrupts here.
            */
           sti
           leal    _C_LABEL(sched_qs)(,%ebx,8),%eax # select q
   
           movl    L_FORW(%eax),%edi       # unlink from front of process q
   #ifdef  DIAGNOSTIC
           cmpl    %edi,%eax               # linked to self (i.e. nothing queued)?
           je      _C_LABEL(switch_error)  # not possible
   #endif /* DIAGNOSTIC */
           movl    L_FORW(%edi),%edx
           movl    %edx,L_FORW(%eax)
           movl    %eax,L_BACK(%edx)
   
           cmpl    %edx,%eax               # q empty?
           jne     3f
   
           btrl    %ebx,%ecx               # yes, clear to indicate empty
           movl    %ecx,_C_LABEL(sched_whichqs) # update q status
   
   3:      /* We just did it. */
           xorl    %eax,%eax
           CLEAR_RESCHED(%eax)
   
   switch_resume:
   #ifdef  DIAGNOSTIC
           cmpl    %eax,L_WCHAN(%edi)      # Waiting for something?
           jne     _C_LABEL(switch_error)  # Yes; shouldn't be queued.
           cmpb    $LSRUN,L_STAT(%edi)     # In run state?
           jne     _C_LABEL(switch_error)  # No; shouldn't be queued.
   #endif /* DIAGNOSTIC */
   
           /* Isolate lwp.  XXX Is this necessary? */
           movl    %eax,L_BACK(%edi)
   
           /* Record new lwp. */
           movb    $LSONPROC,L_STAT(%edi)  # l->l_stat = LSONPROC
           SET_CURLWP(%edi,%ecx)
   
           /* Skip context switch if same lwp. */
           xorl    %ebx,%ebx
           cmpl    %edi,%esi
           je      switch_return
   
           /* If old lwp exited, don't bother. */
           testl   %esi,%esi
           jz      switch_exited
   
           /*
            * Second phase: save old context.
            *
            * Registers:
            *   %eax, %ecx - scratch
            *   %esi - old lwp, then old pcb
            *   %edi - new lwp
            */
   
           pushl   %esi
           call    _C_LABEL(pmap_deactivate2)      # pmap_deactivate(oldproc)
           addl    $4,%esp
   
           movl    L_ADDR(%esi),%esi
   
           /* Save stack pointers. */
           movl    %esp,PCB_ESP(%esi)
           movl    %ebp,PCB_EBP(%esi)
   
   switch_exited:
           /*
            * Third phase: restore saved context.
            *
            * Registers:
            *   %eax, %ebx, %ecx, %edx - scratch
            *   %esi - new pcb
            *   %edi - new lwp
            */
   
           /* No interrupts while loading new state. */
           cli
           movl    L_ADDR(%edi),%esi
   
           /* Restore stack pointers. */
           movl    PCB_ESP(%esi),%esp
           movl    PCB_EBP(%esi),%ebp
   
   #if 0
         /* Don't bother with the rest if switching to a system process. */          /* Don't bother with the rest if switching to a system process. */
         testl   $LW_SYSTEM,L_FLAG(%edi)          testl   $PK_SYSTEM,L_FLAG(%edi);        XXX NJWLWP lwp's don't have PK_SYSTEM!
         jnz     4f          jnz     switch_restored
   #endif
   
         /* Is this process using RAS (restartable atomic sequences)? */          /* Switch TSS. Reset "task busy" flag before loading. */
         movl    L_PROC(%edi),%eax          movl    %cr3,%eax
         cmpl    $0,P_RASLIST(%eax)          movl    %eax,PCB_CR3(%esi) /* XXX should be done by pmap_activate? */
         jne     5f  #ifdef MULTIPROCESSOR
           movl    CPUVAR(GDT),%eax
         /*  #else
          * Restore cr0 (including FPU state).  Raise the IPL to IPL_IPI.          /* Load TSS info. */
          * FPU IPIs can alter the LWP's saved cr0.  Dropping the priority          movl    _C_LABEL(gdt),%eax
          * is deferred until mi_switch(), when cpu_switchto() returns.  #endif
          */          movl    L_MD_TSS_SEL(%edi),%edx
 2:      movl    $IPL_IPI,CPUVAR(ILEVEL)  
         movl    PCB_CR0(%ebx),%ecx          andl    $~0x0200,4(%eax,%edx, 1)
         movl    %cr0,%edx          ltr     %dx
   
           pushl   %edi
           call    _C_LABEL(pmap_activate)         # pmap_activate(p)
           addl    $4,%esp
   
   #if 0
   switch_restored:
   #endif
           /* Restore cr0 (including FPU state). */
           movl    PCB_CR0(%esi),%ecx
   #ifdef MULTIPROCESSOR
         /*          /*
          * If our floating point registers are on a different CPU,           * If our floating point registers are on a different CPU,
          * set CR0_TS so we'll trap rather than reuse bogus state.           * clear CR0_TS so we'll trap rather than reuse bogus state.
          */           */
         movl    PCB_FPCPU(%ebx),%eax          movl    PCB_FPCPU(%esi),%ebx
         cmpl    CPUVAR(SELF),%eax          cmpl    CPUVAR(SELF),%ebx
         je      3f          jz      1f
         orl     $CR0_TS,%ecx          orl     $CR0_TS,%ecx
   1:
         /* Reloading CR0 is very expensive - avoid if possible. */  #endif
 3:      cmpl    %edx,%ecx  
         je      4f  
         movl    %ecx,%cr0          movl    %ecx,%cr0
   
         /* Return to the new LWP, returning 'oldlwp' in %eax. */          /* Record new pcb. */
 4:      movl    %esi,%eax          SET_CURPCB(%esi)
   
           /* Interrupts are okay again. */
           sti
   
   /*
    *  Check for restartable atomic sequences (RAS)
    */
           movl    CPUVAR(CURLWP),%edi
           movl    L_PROC(%edi),%esi
           cmpl    $0,P_RASLIST(%esi)
           jne     2f
   1:
           movl    $1,%ebx
   
   switch_return:
           call    _C_LABEL(sched_unlock_idle)
           cmpl    $0,CPUVAR(IPENDING)
           jz      3f
           pushl   $IPL_NONE               # spl0()
           call    _C_LABEL(spllower)      # process pending interrupts
           addl    $4,%esp
   3:
           movl    $IPL_HIGH,CPUVAR(ILEVEL)        # splhigh()
   
           movl    %ebx,%eax
   
         popl    %edi          popl    %edi
         popl    %esi          popl    %esi
         popl    %ebx          popl    %ebx
         ret          ret
   
         /* Check for restartable atomic sequences (RAS). */  2:                                      # check RAS list
 5:      movl    L_MD_REGS(%edi),%ecx          movl    L_MD_REGS(%edi),%ebx
         pushl   TF_EIP(%ecx)          movl    TF_EIP(%ebx),%eax
         pushl   %eax          pushl   %eax
           pushl   %esi
         call    _C_LABEL(ras_lookup)          call    _C_LABEL(ras_lookup)
         addl    $8,%esp          addl    $8,%esp
         cmpl    $-1,%eax          cmpl    $-1,%eax
         je      2b          je      1b
         movl    %eax,TF_EIP(%ebx)          movl    %eax,TF_EIP(%ebx)
         jmp     2b          jmp     1b
   
   /*
    * void cpu_switchto(struct lwp *current, struct lwp *next)
    * Switch to the specified next LWP.
    */
   ENTRY(cpu_switchto)
           pushl   %ebx
           pushl   %esi
           pushl   %edi
   
   #ifdef DEBUG
           cmpl    $IPL_SCHED,CPUVAR(ILEVEL)
           jae     1f
           pushl   $2f
           call    _C_LABEL(panic)
           /* NOTREACHED */
   2:      .asciz  "not splsched() in cpu_switchto!"
   1:
   #endif /* DEBUG */
   
           movl    16(%esp),%esi           # current
           movl    20(%esp),%edi           # next
   
           /*
            * Clear curlwp so that we don't accumulate system time while idle.
            * This also insures that schedcpu() will move the old process to
            * the correct queue if it happens to get called from the spllower()
            * below and changes the priority.  (See corresponding comment in
            * usrret()).
            *
            * XXX Is this necessary?  We know we won't go idle.
            */
           movl    $0,CPUVAR(CURLWP)
   
           /*
            * We're running at splhigh(), but it's otherwise okay to take
            * interrupts here.
            */
           sti
   
           /* Jump into the middle of cpu_switch */
           xorl    %eax,%eax
           jmp     switch_resume
   
   /*
    * void cpu_exit(struct lwp *l)
    * Switch to the appropriate idle context (lwp0's if uniprocessor; the CPU's
    * if multiprocessor) and deallocate the address space and kernel stack for p.
    * Then jump into cpu_switch(), as if we were in the idle proc all along.
    */
   #ifndef MULTIPROCESSOR
           .globl  _C_LABEL(lwp0)
   #endif
   /* LINTSTUB: Func: void cpu_exit(struct lwp *l) */
   ENTRY(cpu_exit)
           movl    4(%esp),%edi            # old process
   #ifndef MULTIPROCESSOR
           movl    $_C_LABEL(lwp0),%ebx
           movl    L_ADDR(%ebx),%esi
           movl    L_MD_TSS_SEL(%ebx),%edx
   #else
           movl    CPUVAR(IDLE_PCB),%esi
           movl    CPUVAR(IDLE_TSS_SEL),%edx
   #endif
   
           /* Restore the idle context. */
           cli
   
           /* Restore stack pointers. */
           movl    PCB_ESP(%esi),%esp
           movl    PCB_EBP(%esi),%ebp
   
           /* Switch TSS. Reset "task busy" flag before loading. */
           movl    %cr3,%eax
           movl    %eax,PCB_CR3(%esi)
   #ifdef MULTIPROCESSOR
           movl    CPUVAR(GDT),%eax
   #else
           /* Load TSS info. */
           movl    _C_LABEL(gdt),%eax
   #endif
   
           andl    $~0x0200,4-SEL_KPL(%eax,%edx,1)
           ltr     %dx
   
           /* We're always in the kernel, so we don't need the LDT. */
   
           /* Restore cr0 (including FPU state). */
           movl    PCB_CR0(%esi),%ecx
           movl    %ecx,%cr0
   
           /* Record new pcb. */
           SET_CURPCB(%esi)
   
           /* Now off the CPU. */
           movl    $0,CPUVAR(CURLWP)
   
           /* Interrupts are okay again. */
           sti
   
           /* Jump into cpu_switch() with the right state. */
           xorl    %esi,%esi
           jmp     idle_start
   
 /*  /*
  * void savectx(struct pcb *pcb);   * void savectx(struct pcb *pcb);
  *  
  * Update pcb, saving current processor state.   * Update pcb, saving current processor state.
  */   */
   /* LINTSTUB: Func: void savectx(struct pcb *pcb) */
 ENTRY(savectx)  ENTRY(savectx)
         movl    4(%esp),%edx            # edx = pcb          movl    4(%esp),%edx            # edx = p->p_addr
   
           /* Save stack pointers. */
         movl    %esp,PCB_ESP(%edx)          movl    %esp,PCB_ESP(%edx)
         movl    %ebp,PCB_EBP(%edx)          movl    %ebp,PCB_EBP(%edx)
   
         ret          ret
   
 /*  /*
  * osyscall()  
  *  
  * Old call gate entry for syscall   * Old call gate entry for syscall
  */   */
   /* LINTSTUB: Var: char Xosyscall[1]; */
 IDTVEC(osyscall)  IDTVEC(osyscall)
         pushfl                  # set eflags in trap frame          /* Set eflags in trap frame. */
           pushfl
         popl    8(%esp)          popl    8(%esp)
         pushl   $7              # size of instruction for restart          pushl   $7              # size of instruction for restart
         jmp     syscall1          jmp     syscall1
   
 /*  /*
  * syscall()  
  *  
  * Trap gate entry for syscall   * Trap gate entry for syscall
  */   */
   /* LINTSTUB: Var: char Xsyscall[1]; */
 IDTVEC(syscall)  IDTVEC(syscall)
         pushl   $2              # size of instruction for restart          pushl   $2              # size of instruction for restart
 syscall1:  syscall1:
Line 897  syscall1:
Line 1300  syscall1:
  * latch stuff in probintr() can be moved to npxprobe().   * latch stuff in probintr() can be moved to npxprobe().
  */   */
   
 /*  /* LINTSTUB: Func: void probeintr(void) */
  * void probeintr(void)  
  */  
 NENTRY(probeintr)  NENTRY(probeintr)
         ss          ss
         incl    _C_LABEL(npx_intrs_while_probing)          incl    _C_LABEL(npx_intrs_while_probing)
Line 912  NENTRY(probeintr)
Line 1313  NENTRY(probeintr)
         popl    %eax          popl    %eax
         iret          iret
   
 /*  /* LINTSTUB: Func: void probetrap(void) */
  * void probetrap(void)  
  */  
 NENTRY(probetrap)  NENTRY(probetrap)
         ss          ss
         incl    _C_LABEL(npx_traps_while_probing)          incl    _C_LABEL(npx_traps_while_probing)
         fnclex          fnclex
         iret          iret
   
 /*  /* LINTSTUB: Func: int npx586bug1(int a, int b) */
  * int npx586bug1(int a, int b)  
  */  
 NENTRY(npx586bug1)  NENTRY(npx586bug1)
         fildl   4(%esp)         # x          fildl   4(%esp)         # x
         fildl   8(%esp)         # y          fildl   8(%esp)         # y

Legend:
Removed from v.1.45.2.8  
changed lines
  Added in v.1.46

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