[Cbe-oss-dev] [PATCH 9/10] MARS: remove separate atomic implementation

[Kazunori Asayama]

Yuji Mano wrote:
> This removes the atomic.h headers for both host and mpu. Since the atomics are
> now used only in the mutex implementation, we get rid of the extra abstraction
> and use the atomic intrinsics directly in the mutex implementations.
> 
> Signed-off-by: Yuji Mano <yuji.mano at am.sony.com>
> 

(snip)
> --- a/src/mpu/lib/mars_mutex.c
> +++ b/src/mpu/lib/mars_mutex.c
> @@ -35,8 +35,9 @@
>   * LIBRARY OR THE USE OR OTHER DEALINGS IN THE LIBRARY.
>   */
>  
> +#include <spu_mfcio.h>
> +
>  #include "mars/mars_mutex.h"
> -#include "mars/mars_atomic.h"
>  #include "mars/mars_dma.h"
>  #include "mars/mars_error.h"
>  #include "mars/mars_debug.h"
> @@ -78,21 +79,33 @@ int mars_mutex_lock_get(uint64_t mutex_e
>  
>  	int status;
>  
> -	atomic_event_setup();
> +	/* clear phantom events and set event mask */
> +	if (spu_stat_event_status())
> +		spu_write_event_ack(spu_read_event_status());

In this algorithm, even if phantom events are received, status of mutex
is checked again automatically, so I think we have no need to clear such
events here explicitly.

> +	spu_write_event_mask(MFC_LLR_LOST_EVENT);
>  
>  	do {
> -		atomic_get(mutex, mutex_ea);
> +		mfc_getllar(mutex, mutex_ea, 0, 0);
> +		mfc_read_atomic_status();
>  
>  		if (mutex->lock == MARS_MUTEX_LOCKED) {
> -			atomic_event_wait();
> +			spu_read_event_status();
> +			spu_write_event_ack(MFC_LLR_LOST_EVENT);
>  			status = 1;
>  		} else {
>  			mutex->lock = MARS_MUTEX_LOCKED;
> -			status = atomic_put(mutex, mutex_ea);
> +			mfc_putllc(mutex, mutex_ea, 0, 0);
> +			status = mfc_read_atomic_status() & MFC_PUTLLC_STATUS;
>  		}
>  	} while (status);
>  
> -	atomic_event_restore();
> +	/* clean up any remnant events, as needed */
> +	spu_write_event_mask(0);
> +
> +	if (spu_stat_event_status()) {
> +		spu_read_event_status();
> +		spu_write_event_ack(MFC_LLR_LOST_EVENT);
> +	}
>  
>  	return MARS_SUCCESS;
>  }
> 
> 

-- 
(ASAYAMA Kazunori
  (asayama at sm.sony.co.jp))
t