FreeBSD/Linux Kernel Cross Reference
sys/i386/include/lock.h

     /*
      * Copyright (c) 1997, by Steve Passe
      * All rights reserved.
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
      *    notice, this list of conditions and the following disclaimer.
     * 2. The name of the developer may NOT be used to endorse or promote products
     *    derived from this software without specific prior written permission.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     * $FreeBSD$
     */
    
    
    #ifndef _MACHINE_LOCK_H_
    #define _MACHINE_LOCK_H_
    
    
    #ifdef LOCORE
    
    #ifdef SMP
    
    #define MPLOCKED        lock ;
    
    /*
     * Some handy macros to allow logical organization.
     */
    
    #define MP_LOCK         call    _get_mplock
    
    #define MP_TRYLOCK                                                      \
            pushl   $_mp_lock ;                     /* GIANT_LOCK */        \
            call    _MPtrylock ;                    /* try to get lock */   \
            add     $4, %esp
    
    #define MP_RELLOCK                                                      \
            movl    $_mp_lock,%edx ;                /* GIANT_LOCK */        \
            call    _MPrellock_edx
    
    /*
     * Protects the IO APIC and apic_imen as a critical region.
     */
    #define IMASK_LOCK                                                      \
            pushl   $_imen_lock ;                   /* address of lock */   \
            call    _s_lock ;                       /* MP-safe */           \
            addl    $4, %esp
    
    #define IMASK_UNLOCK                                                    \
            movl    $0, _imen_lock
    
    #else  /* SMP */
    
    #define MPLOCKED                                /* NOP */
    
    #define MP_LOCK                                 /* NOP */
    
    #endif /* SMP */
    
    #else /* LOCORE */
    
    #ifdef SMP
    
    #include <machine/smptests.h>                   /** xxx_LOCK */
    
    /*
     * Locks regions protected in UP kernel via cli/sti.
     */
    #ifdef USE_MPINTRLOCK
    #define MPINTR_LOCK()   s_lock(&mpintr_lock)
    #define MPINTR_UNLOCK() s_unlock(&mpintr_lock)
    #else
    #define MPINTR_LOCK()
    #define MPINTR_UNLOCK()
    #endif /* USE_MPINTRLOCK */
    
    /*
     * sio/cy lock.
     * XXX should rc (RISCom/8) use this?
     */
    #ifdef USE_COMLOCK
    #define COM_LOCK()      s_lock(&com_lock)
    #define COM_UNLOCK()    s_unlock(&com_lock)
    #define COM_DISABLE_INTR() \
                    { __asm __volatile("cli" : : : "memory"); COM_LOCK(); }
    #define COM_ENABLE_INTR() \
                   { COM_UNLOCK(); __asm __volatile("sti"); }
   #else
   #define COM_LOCK()
   #define COM_UNLOCK()
   #define COM_DISABLE_INTR()      disable_intr()
   #define COM_ENABLE_INTR()       enable_intr()
   #endif /* USE_COMLOCK */
   
   /* 
    * Clock hardware/struct lock.
    * XXX pcaudio and friends still need this lock installed.
    */
   #ifdef USE_CLOCKLOCK
   #define CLOCK_LOCK()    s_lock(&clock_lock)
   #define CLOCK_UNLOCK()  s_unlock(&clock_lock)
   #define CLOCK_DISABLE_INTR() \
                   { __asm __volatile("cli" : : : "memory"); CLOCK_LOCK(); }
   #define CLOCK_ENABLE_INTR() \
                   { CLOCK_UNLOCK(); __asm __volatile("sti"); }
   #else
   #define CLOCK_LOCK()
   #define CLOCK_UNLOCK()
   #define CLOCK_DISABLE_INTR()    disable_intr()
   #define CLOCK_ENABLE_INTR()     enable_intr()
   #endif /* USE_CLOCKLOCK */
   
   #else /* SMP */
   
   #define MPINTR_LOCK()
   #define MPINTR_UNLOCK()
   
   #define COM_LOCK()
   #define COM_UNLOCK()
   #define CLOCK_LOCK()
   #define CLOCK_UNLOCK()
   
   #endif /* SMP */
   
   /*
    * Simple spin lock.
    * It is an error to hold one of these locks while a process is sleeping.
    */
   struct simplelock {
           volatile int    lock_data;
   };
   
   /* functions in simplelock.s */
   void    s_lock_init             __P((struct simplelock *));
   void    s_lock                  __P((struct simplelock *));
   int     s_lock_try              __P((struct simplelock *));
   void    ss_lock                 __P((struct simplelock *));
   void    ss_unlock               __P((struct simplelock *));
   void    s_lock_np               __P((struct simplelock *));
   void    s_unlock_np             __P((struct simplelock *));
   
   /* inline simplelock functions */
   static __inline void
   s_unlock(struct simplelock *lkp)
   {
           lkp->lock_data = 0;
   }
   
   /* global data in mp_machdep.c */
   extern struct simplelock        imen_lock;
   extern struct simplelock        cpl_lock;
   extern struct simplelock        fast_intr_lock;
   extern struct simplelock        intr_lock;
   extern struct simplelock        clock_lock;
   extern struct simplelock        com_lock;
   extern struct simplelock        mpintr_lock;
   extern struct simplelock        mcount_lock;
   
   #if !defined(SIMPLELOCK_DEBUG) && MAXCPU > 1
   /*
    * This set of defines turns on the real functions in i386/isa/apic_ipl.s.
    */
   #define simple_lock_init(alp)   s_lock_init(alp)
   #define simple_lock(alp)        s_lock(alp)
   #define simple_lock_try(alp)    s_lock_try(alp)
   #define simple_unlock(alp)      s_unlock(alp)
   
   #endif /* !SIMPLELOCK_DEBUG && MAXCPU > 1 */
   
   #endif /* LOCORE */
   
   #endif /* !_MACHINE_LOCK_H_ */

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