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Diff for /src/sys/arch/i386/i386/locore.S between version 1.45.2.5 and 1.45.2.6

version 1.45.2.5, 2007/03/24 18:30:36 version 1.45.2.6, 2007/03/29 19:00:24
Line 1 
Line 1 
 /*      $NetBSD$        */  /*      $NetBSD$        */
   
 /*-  /*-
  * Copyright (c) 1998, 2000, 2004 The NetBSD Foundation, Inc.   * Copyright (c) 1998, 2000, 2004, 2006, 2007 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 94 
Line 89 
 #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>
   
 /* 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 142 
Line 109 
         .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 170  _C_LABEL(lapic_tpr):
Line 135  _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 625  begin:
Line 588  begin:
   
 /*  /*
  * void lwp_trampoline(void);   * void lwp_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!
  */   */
 /* LINTSTUB: Func: void lwp_trampoline(void) */  
 NENTRY(lwp_trampoline)  NENTRY(lwp_trampoline)
         pushl   %ebp          pushl   %ebp
         xorl    %ebp,%ebp          xorl    %ebp,%ebp
Line 645  NENTRY(lwp_trampoline)
Line 608  NENTRY(lwp_trampoline)
         INTRFASTEXIT          INTRFASTEXIT
         /* NOTREACHED */          /* NOTREACHED */
   
 /*****************************************************************************/  
 #ifdef COMPAT_16  
 /*  /*
  * Signal trampoline; copied to top of user stack.   * sigcode()
    *
    * 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 665  NENTRY(sigcode)
Line 628  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 703  NENTRY(lgdt)
Line 659  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
   
 /*****************************************************************************/  
   
 /*  /*
  * These functions are primarily used by DDB.   * int setjmp(label_t *)
    *
    * 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 726  ENTRY(setjmp)
Line 684  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 739  ENTRY(longjmp)
Line 701  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
         xorl    %eax,%eax               # return (1);          movl    $1,%eax                 # return 1
         incl    %eax  
         ret          ret
   
 /*****************************************************************************/  
   
         .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)   * struct lwp *cpu_switchto(struct lwp *oldlwp, struct newlwp)
  *   *
  *      1. if (oldlwp != NULL), save its context.   *      1. if (oldlwp != NULL), save its context.
  *      2. then, restore context of newlwp.   *      2. then, restore context of newlwp.
  *   *
  * Note that the stack frame layout is known to "struct switchframe"   * Note that the stack frame layout is known to "struct switchframe" in
  * in <machine/frame.h> and to the code in cpu_lwp_fork() which initializes   * <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_switchto)
Line 772  ENTRY(cpu_switchto)
Line 721  ENTRY(cpu_switchto)
   
         movl    16(%esp),%esi           # oldlwp          movl    16(%esp),%esi           # oldlwp
         movl    20(%esp),%edi           # newlwp          movl    20(%esp),%edi           # newlwp
   
         testl   %esi,%esi          testl   %esi,%esi
         jz      switch_skipsave          jz      1f
   
         /*  
          * Save old context.  
          */  
   
           /* Save old context. */
         movl    L_ADDR(%esi),%eax          movl    L_ADDR(%esi),%eax
         movl    %esp,PCB_ESP(%eax)          movl    %esp,PCB_ESP(%eax)
         movl    %ebp,PCB_EBP(%eax)          movl    %ebp,PCB_EBP(%eax)
   
 switch_skipsave:          /* Switch to newlwp's stack. */
   1:      movl    L_ADDR(%edi),%ebx
         /*  
          * Switch to newlwp's stack.  
          */  
   
         movl    L_ADDR(%edi),%ebx  
         movl    PCB_EBP(%ebx),%ebp          movl    PCB_EBP(%ebx),%ebp
         movl    PCB_ESP(%ebx),%esp          movl    PCB_ESP(%ebx),%esp
   
         /*          /* Switch TSS.  Reset "task busy" flag before loading. */
          * Restore the rest of newlwp's context.  
          *  
          * Registers:  
          *   %ebx - new pcb  
          *   %edi - new lwp  
          */  
   
 #if 0  
         /* Don't bother with the rest if switching to a system process. */  
         testl   $LK_SYSTEM,L_FLAG(%edi);  
         jnz     switch_restored  
 #endif  
   
         /* 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(%ebx)      # for TSS gates
   
 #ifdef MULTIPROCESSOR  
         movl    CPUVAR(GDT),%eax          movl    CPUVAR(GDT),%eax
 #else  
         /* Load TSS info. */  
         movl    _C_LABEL(gdt),%eax  
 #endif  
         movl    L_MD_TSS_SEL(%edi),%edx          movl    L_MD_TSS_SEL(%edi),%edx
   
         andl    $~0x0200,4(%eax,%edx, 1)          andl    $~0x0200,4(%eax,%edx, 1)
         ltr     %dx          ltr     %dx
   
 #if 0          movl    $0,CPUVAR(RESCHED)      # XXX should not be here
 switch_restored:  
 #endif          /* Don't bother with the rest if switching to a system process. */
           testl   $LW_SYSTEM,L_FLAG(%edi)
           jnz     3f
   
         movl    $0,CPUVAR(RESCHED)          /* Is this process using RAS (restartable atomic sequences)? */
           movl    L_PROC(%edi),%eax
           cmpl    $0,P_RASLIST(%eax)
           jne     4f
   
         /* Restore cr0 (including FPU state). */          /*
         movl    $IPL_IPI,CPUVAR(ILEVEL)           * Restore cr0 (including FPU state).  Raise the IPL to IPL_IPI.
            * FPU IPIs can alter the LWP's saved cr0.  Dropping the priority
            * is deferred until mi_switch(), when cpu_switchto() returns.
            */
   2:      movl    $IPL_IPI,CPUVAR(ILEVEL)
         movl    PCB_CR0(%ebx),%ecx          movl    PCB_CR0(%ebx),%ecx
         movl    %cr0,%edx          movl    %cr0,%edx
 #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.           * set CR0_TS so we'll trap rather than reuse bogus state.
Line 841  switch_restored:
Line 769  switch_restored:
         movl    PCB_FPCPU(%ebx),%eax          movl    PCB_FPCPU(%ebx),%eax
         cmpl    CPUVAR(SELF),%eax          cmpl    CPUVAR(SELF),%eax
         movl    $0,%eax          movl    $0,%eax
         setne   %al             /* CR0_TS is bit 0 */          setne   %al                     # CR0_TS is bit 0
         orl     %eax,%ecx          orl     %eax,%ecx
 #endif  
         /* Reloading CR0 is very expensive - avoid if possible. */          /* Reloading CR0 is very expensive - avoid if possible. */
         cmpl    %edx,%ecx          cmpl    %edx,%ecx
         je      2f          je      3f
         movl    %ecx,%cr0          movl    %ecx,%cr0
 2:  
         /*  
          * Interrupts are okay again.  Any pending IPIs will be  
          * deferred until cpu_switchto() returns, when the priority  
          * level will be dropped.  
          */  
         movl    $IPL_SCHED,CPUVAR(ILEVEL)  
   
         /*  
          *  Check for restartable atomic sequences (RAS)  
          */  
   
         movl    L_PROC(%edi),%ebx  
         cmpl    $0,P_RASLIST(%ebx)  
         jne     check_ras  
   
 switch_return:          /* Return to the new LWP, returning 'oldlwp' in %eax. */
         movl    %esi,%eax       # return 'oldlwp'  3:      movl    %esi,%eax
         popl    %edi          popl    %edi
         popl    %esi          popl    %esi
         popl    %ebx          popl    %ebx
         ret          ret
   
 check_ras:          /* Check for restartable atomic sequences (RAS). */
         movl    L_MD_REGS(%edi),%ebx  4:      movl    L_MD_REGS(%edi),%ecx
         pushl   TF_EIP(%ebx)          pushl   TF_EIP(%ecx)
         pushl   L_PROC(%edi)          pushl   %eax
         call    _C_LABEL(ras_lookup)          call    _C_LABEL(ras_lookup)
         addl    $8,%esp          addl    $8,%esp
         cmpl    $-1,%eax          cmpl    $-1,%eax
         je      switch_return          je      2b
         movl    %eax,TF_EIP(%ebx)          movl    %eax,TF_EIP(%ebx)
         jmp     switch_return          jmp     2b
   
 /*  /*
  * 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 = pcb
   
         /* 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)
         /* Set eflags in trap frame. */          pushfl                  # 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 986  syscall1:
Line 897  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 999  NENTRY(probeintr)
Line 912  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.1.45.2.5  
changed lines
  Added in v.1.45.2.6

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