source: mainline/kernel/arch/sparc64/include/barrier.h@ 42742c5a

/*
 * Copyright (c) 2005 Jakub Jermar
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author 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 ``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 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.
 */

/** @addtogroup sparc64 
 * @{
 */
/** @file
 */

#ifndef KERN_sparc64_BARRIER_H_
#define KERN_sparc64_BARRIER_H_

/*
 * Our critical section barriers are prepared for the weakest RMO memory model.
 */
#define CS_ENTER_BARRIER()                              \
        asm volatile (                                  \
                "membar #LoadLoad | #LoadStore\n"       \
                ::: "memory"                            \
        )
#define CS_LEAVE_BARRIER()                              \
        asm volatile (                                  \
                "membar #StoreStore\n"                  \
                "membar #LoadStore\n"                   \
                ::: "memory"                            \
        )

#define memory_barrier()        \
        asm volatile ("membar #LoadLoad | #StoreStore\n" ::: "memory")
#define read_barrier()          \
        asm volatile ("membar #LoadLoad\n" ::: "memory")
#define write_barrier()         \
        asm volatile ("membar #StoreStore\n" ::: "memory")

#define flush(a)                \
        asm volatile ("flush %0\n" :: "r" ((a)) : "memory")

/** Flush Instruction pipeline. */
static inline void flush_pipeline(void)
{
        /*
         * The FLUSH instruction takes address parameter.
         * As such, it may trap if the address is not found in DTLB.
         *
         * The entire kernel text is mapped by a locked ITLB and
         * DTLB entries. Therefore, when this function is called,
         * the %o7 register will always be in the range mapped by
         * DTLB.
         */
         
        asm volatile ("flush %o7\n");
}

/** Memory Barrier instruction. */
static inline void membar(void)
{
        asm volatile ("membar #Sync\n");
}

#if defined (US)

#define smc_coherence(a)        \
{                               \
        write_barrier();        \
        flush((a));             \
}

#define FLUSH_INVAL_MIN         4
#define smc_coherence_block(a, l)                       \
{                                                       \
        unsigned long i;                                \
        write_barrier();                                \
        for (i = 0; i < (l); i += FLUSH_INVAL_MIN)      \
                flush((void *)(a) + i);                 \
}

#elif defined (US3)

#define smc_coherence(a)        \
{                               \
        write_barrier();        \
        flush_pipeline();       \
}

#define smc_coherence_block(a, l)       \
{                                       \
        write_barrier();                \
        flush_pipeline();               \
}

#endif  /* defined(US3) */

#endif

/** @}
 */