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#ifndef __I386_SMPLOCK_H

#define __I386_SMPLOCK_H

#ifdef __SMP__

/*

 *      Locking the kernel

 */

extern __inline void lock_kernel(void)

{

        unsigned long flags;

        int proc = smp_processor_id();

        save_flags(flags);

        cli();

        /* set_bit works atomic in SMP machines */

        while(set_bit(0, (void *)&kernel_flag))

        {

                /*

                 *      We just start another level if we have the lock

                 */

                if (proc == active_kernel_processor)

                        break;

                do

                {

#ifdef __SMP_PROF__             

                        smp_spins[smp_processor_id()]++;

#endif                  

                        /*

                         *      Doing test_bit here doesn't lock the bus

                         */

                        if (test_bit(proc, (void *)&smp_invalidate_needed))

                                if (clear_bit(proc, (void *)&smp_invalidate_needed))

                                        local_flush_tlb();

                }

                while(test_bit(0, (void *)&kernel_flag));

        }

        /*

         *      We got the lock, so tell the world we are here and increment

         *      the level counter

         */

        active_kernel_processor = proc;

        kernel_counter++;

        restore_flags(flags);

}

extern __inline void unlock_kernel(void)

{

        unsigned long flags;

        save_flags(flags);

        cli();

        /*

         *      If it's the last level we have in the kernel, then

         *      free the lock

         */

        if (kernel_counter == 0)

                panic("Kernel counter wrong.\n"); /* FIXME: Why is kernel_counter sometimes 0 here? */

        if(! --kernel_counter)

        {

                active_kernel_processor = NO_PROC_ID;

                clear_bit(0, (void *)&kernel_flag);

        }

        restore_flags(flags);

}

#endif

#endif