FreeBSD/Linux Kernel Cross Reference
sys/sqt/sqtasm.h

     /* 
      * Mach Operating System
      * Copyright (c) 1991 Carnegie Mellon University
      * Copyright (c) 1991 Sequent Computer Systems
      * All Rights Reserved.
      * 
      * Permission to use, copy, modify and distribute this software and its
      * documentation is hereby granted, provided that both the copyright
      * notice and this permission notice appear in all copies of the
     * software, derivative works or modified versions, and any portions
     * thereof, and that both notices appear in supporting documentation.
     * 
     * CARNEGIE MELLON AND SEQUENT COMPUTER SYSTEMS ALLOW FREE USE OF
     * THIS SOFTWARE IN ITS "AS IS" CONDITION.  CARNEGIE MELLON AND
     * SEQUENT COMPUTER SYSTEMS DISCLAIM ANY LIABILITY OF ANY KIND FOR
     * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     * 
     * Carnegie Mellon requests users of this software to return to
     * 
     *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
     *  School of Computer Science
     *  Carnegie Mellon University
     *  Pittsburgh PA 15213-3890
     * 
     * any improvements or extensions that they make and grant Carnegie Mellon 
     * the rights to redistribute these changes.
     */
    
    /*
     * HISTORY
     * $Log:        sqtasm.h,v $
     * Revision 2.3  91/07/31  18:04:22  dbg
     *      Changed copyright.
     *      [91/07/31            dbg]
     * 
     * Revision 2.2  91/05/08  13:00:26  dbg
     *      Changes for pure kernel.
     *      [90/05/02            dbg]
     * 
     */
    
    #ifndef _SQT_SQTASM_H_
    #define _SQT_SQTASM_H_
    
    #if     defined(KXX) || defined(SLIC_GATES)
    
    /*
     * In-line ASM macros for portable gate and lock implementations.
     * Macros don't block interrupts; caller must do this.
     *
     * P_GATE_ASM   grab a gate, used in ASM code.
     * CP_GATE_ASM  conditionally grab a gate, used in ASM code.
     * V_GATE_ASM   release a gate in ASM code.
     *
     * These macros touch only EAX.
     */
    
    /*
     * P_SLIC_GATE and V_SLIC_GATE lock/unlock slic gate whose number is in %al.
     * Since these may be called from (eg) p_gate() and cp_gate(), the must be
     * sure to save/restore interrupt enable flag.  This is ok in the prototype
     * (K20), and a non-issue on the real HW.
     */
    
    #define P_SLIC_GATE(gateno) \
            pushfl; cli; \
            movb    $GATE_GROUP, SL_DEST+VA_SLIC; \
            movb    gateno, SL_SMESSAGE+VA_SLIC; \
    9:      movb    $SL_REQG, SL_CMD_STAT+VA_SLIC; \
    8:      testb   $SL_BUSY, SL_CMD_STAT+VA_SLIC; \
            jne     8b; \
            testb   $SL_OK, SL_CMD_STAT+VA_SLIC; \
            je      9b
    
    #define V_SLIC_GATE(gateno) \
            movb    $GATE_GROUP, SL_DEST+VA_SLIC; \
            movb    gateno, SL_SMESSAGE+VA_SLIC; \
            movb    $SL_RELG, SL_CMD_STAT+VA_SLIC; \
    9:      testb   $SL_BUSY, SL_CMD_STAT+VA_SLIC; \
            jne     9b; \
            popfl
    
    #define P_GATE_ASM(gaddr) \
            leal    gaddr, %eax; \
            shrb    $2, %al; \
            andb    $0x3f, %al; \
    5:      cmpb    $G_UNLOCKED, gaddr; \
            jne     5b; \
            P_SLIC_GATE(%al); \
            movb    gaddr, %ah; \
            cmpb    $G_UNLOCKED, %ah; \
            jne     6f; \
            movb    $G_LOCKED, gaddr; \
    6:      V_SLIC_GATE(%al); \
            cmpb    $G_UNLOCKED, %ah; \
            jne     5b
    
    #define CP_GATE_ASM(gaddr,fail) \
            leal    gaddr, %eax; \
           shrb    $2, %al; \
           andb    $0x3f, %al; \
           P_SLIC_GATE(%al); \
           movb    gaddr, %ah; \
           cmpb    $G_UNLOCKED, %ah; \
           jne     6f; \
           movb    $G_LOCKED, gaddr; \
   6:      V_SLIC_GATE(%al); \
           cmpb    $G_UNLOCKED, %ah; \
           jne     fail
   
   #define V_GATE_ASM(gaddr)       movb    $G_UNLOCKED, gaddr
   
   #else   Real HW
   
   /*
    * Gate and lock accesses on real HW are in-line expanded.
    * See machine/mutex.h
    */
   
   #define V_GATE_ASM(gaddr) \
           movb    $G_UNLOCKED, %al; \
           xchgb   %al, gaddr
   
   #endif  KXX
   
   /*
    * V_LOCK_ASM() assumes gate and lock data-structure and values are idential.
    */
   
   #define V_LOCK_ASM(lock)        V_GATE_ASM(lock)
   
   /*
    * SPL_ASM(new,old)     raise SPL to "new", put old value in "old" (mod's %ah).
    * SPLX_ASM(old)        lower SPL back to "old".
    *
    * See machine/intctl.h for detail on spl synch with SLIC.
    * need 8 clocks at 16Mhz 10 at 20 Mhz  12 at 24 Mhz etc
    * modelC requires an extra 50 ns
    * all machines may run at 10% margins.
    * Note: movb X,r       will contribute 2 cycles
    *       nop            is 3 cycles
    *       movl   r,r     is 2 cycles
    */
   
   #ifndef MHz
   #define MHz     20
   #endif  MHz
   
   /***************SLICSYNC 2 ***************************************/
   #if MHz == 16
   #define SPL_ASM(new,old) \
           movb    VA_SLIC+SL_LMASK, old; \
           movb    new, VA_SLIC+SL_LMASK; \
           movb    VA_SLIC+SL_LMASK, %ah; \
           nop; nop;
   #else
   #if MHz == 20
   #define SPL_ASM(new,old) \
           movb    VA_SLIC+SL_LMASK, old; \
           movb    new, VA_SLIC+SL_LMASK; \
           movb    VA_SLIC+SL_LMASK, %ah; \
           movl    %eax,%eax; \
           movl    %eax,%eax; \
           nop; nop; 
   #else
           ERROR not 16Mhz nor 20Hz
   #endif
   #endif
   
   #define SPLX_ASM(old)   movb    old, VA_SLIC+SL_LMASK
   
   /*
    * Put cpu_number() is passed arg
    */
   
   #define CPU_NUMBER(arg) \
           movzbl  VA_SLIC+SL_PROCID, arg; \
           movzbl  _slic_to_cpu(arg), arg
   
   /*
    * Put current_thread pointer into passed arg
    * See current_thread() defn in thread.h
    */
   
   #define CURRENT_THREAD(arg) \
           CPU_NUMBER(arg); \
           movl    _active_threads(,arg,4), arg
   
   /*
    * Put pointer to current pcb in arg
    */
   
   #define CURRENT_PCB(arg) \
           CURRENT_THREAD(arg); \
           movl    THREAD_PCB(arg), arg
   
   /*
    * Put pointer to engine[] structure in arg
    */
   
   #define ENGINE_POINTER(arg) \
           CPU_NUMBER(arg); \
           imull   $ENGSIZE, arg; \
           addl    _engine, arg
   
   /*
    * Put pointer to plocal structure in arg
    */
   
   #define LOCAL_POINTER(arg) \
           ENGINE_POINTER(arg); \
           movl    E_LOCAL(arg), arg
   
   #endif  /* _SQT_SQTASM_H_ */

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