read_unlock.h

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#ifndef _SPU_READ_UNLOCK_H_
#define _SPU_READ_UNLOCK_H_

#include "sync_utils.h"
#include "mutex.h"
#include <spu_mfcio.h>


/**
 * read_unlock - release reader lock.
 * @ea: handle to effective address of lock variable.
 * 
 * Description: Release a reader lock.  The only restriction 
 * here is that @ea must be word aligned.
 *
 * Context: This routine should be used when interrupts
 * do not need to be re-enabled --either because interrupts
 * are not being used, or because the application will take
 * steps to re-enable them later.
 */
static __inline void _read_unlock(eaddr_t ea)
{
    DECL_MUTEX_VARS();
    s32 status;

    /* _read_unlock
     *
     *    Reader locks must use PUTLLC when releasing, instead of
     *    the more traditional PUTLLUC because of the non-exclusive
     *    nature of the lock.  The reason for this is that other
     *    readers may have incremented the counter, and we don't
     *    want to corrupt it by blindly issuing PUTLLUC!!
     */
    ea64.ull = ALIGN128_EA(ea);
    offset = OFFSET128_EA_U32(ea);
    do {
        MFC_DMA(buf, ea64, size, tagid, MFC_GETLLAR_CMD);
        spu_readch(MFC_RdAtomicStat);

        buf[offset] -= 1;
        MFC_DMA(buf, ea64, size, tagid, MFC_PUTLLC_CMD);
        status = spu_readch(MFC_RdAtomicStat);
    } while (status != 0);

}


#endif /* _SPU_READ_UNLOCK_H_ */