[Cbe-oss-dev] [PATCH/RFC] libspe2: add support for multi source sync

[Kazunori Asayama]

Gerhard Stenzel <stenzel at de.ibm.com> wrote:
> The following patch/RFC adds and implements two API functions
> to support the MFC Multisource Synchronization facility.
> 
> Comments are appreciated.
> 
> Signed-off-by: Gerhard Stenzel <stenzel at de.ibm.com>
> 
> ===================================================================
> Index: libspe2/libspe2.c
> ===================================================================
> --- libspe2/libspe2.c	(revision 57)
> +++ libspe2/libspe2.c	(working copy)
> @@ -363,6 +363,29 @@ int spe_out_intr_mbox_status (spe_contex
>  }
>  
>  /*
> + * Multisource Sync Facility
> + */
> +
> +int spe_mssync_start(spe_context_ptr_t spe)
> +{
> +	if (spe == NULL ) {
> +		errno = ESRCH;
> +		return -1;
> +	}
> +	return _base_spe_mssync_start(spe);
> +}
> +
> +int spe_mssync_status(spe_context_ptr_t spe)
> +{
> +	if (spe == NULL ) {
> +		errno = ESRCH;
> +		return -1;
> +	}
> +	return _base_spe_mssync_status(spe);
> +}
> +
> +
> +/*
>   * SPU SIgnal Notification Facility
>   */
>  
> Index: libspe2/spebase/dma.c
> ===================================================================
> --- libspe2/spebase/dma.c	(revision 57)
> +++ libspe2/spebase/dma.c	(working copy)
> @@ -321,3 +321,50 @@ int _base_spe_mfcio_tag_status_read(spe_
>  		return -1;
>  	}
>  }
> +
> +int _base_spe_mssync_start(spe_context_ptr_t spectx)
> +{
> +	int ret, fd;
> +	unsigned int data = 1; /* Any value can be written here */
> +
> +	volatile struct spe_mssync_area *mss_area = 
> +                spectx->base_private->mssync_mmap_base;
> +
> +	if (spectx->base_private->flags & SPE_MAP_PS) {
> +		mss_area->MFC_MSSync = data; 
> +		return 0;
> +	} else {
> +		fd = open_if_closed(spectx, FD_MSS, 0);
> +		if (fd != -1) {
> +			ret = write(fd, &data, sizeof (data));
> +			if ((ret < 0) && (errno != EIO)) {
> +				perror("spe_mssync_start: internal error");
> +			}
> +		return ret < 0 ? -1 : 0;
> +		}

An indeterminate value is returned when fd == -1. In this case, -1
must be returned.

> +	}
> +}
> +
> +unsigned int _base_spe_mssync_status(spe_context_ptr_t spectx)

The function _base_spe_mssync_status must return an 'int' value.

> +{
> +	int ret, fd;
> +	unsigned int data;
> +
> +	volatile struct spe_mssync_area *mss_area = 
> +                spectx->base_private->mssync_mmap_base;
> +
> +	if (spectx->base_private->flags & SPE_MAP_PS) {
> +		return  mss_area->MFC_MSSync;
> +	} else {
> +		fd = open_if_closed(spectx, FD_MSS, 0);
> +		if (fd != -1) {
> +			ret = read(fd, &data, sizeof (data));
> +			if ((ret < 0) && (errno != EIO)) {
> +				perror("spe_mssync_start: internal error");
> +			}
> +		return data;

The function _base_spe_mssync_status must return -1 in error
conditions.

> +		}
> +	}
> +}
> +
> +
> Index: libspe2/spebase/spebase.h
> ===================================================================
> --- libspe2/spebase/spebase.h	(revision 57)
> +++ libspe2/spebase/spebase.h	(working copy)
> @@ -663,6 +663,21 @@ int _base_spe_cpu_info_get(int info_requ
>   */
>  void  __spe_context_update_event(void);
>  
> +/**
> + * _base_spe_mssync_start starts Multisource Synchronisation
> + *
> + * @param spectx Specifies the SPE context
> + */
> +int _base_spe_mssync_start(spe_context_ptr_t spectx);
> +
> +/**
> + * _base_spe_mssync_status retrieves status of Multisource Synchronisation
> + *
> + * @param spectx Specifies the SPE context
> + */
> +unsigned int _base_spe_mssync_status(spe_context_ptr_t spectx);

Ditto.

> +
> +
>  #ifdef __cplusplus
>  }
>  #endif
> Index: libspe2/libspe2.h
> ===================================================================
> --- libspe2/libspe2.h	(revision 57)
> +++ libspe2/libspe2.h	(working copy)
> @@ -165,6 +165,13 @@ int spe_out_intr_mbox_read (spe_context_
>  int spe_out_intr_mbox_status (spe_context_ptr_t spe);
>  
>  /*
> + * Multisource Sync Facility
> + */
> +int spe_mssync_start(spe_context_ptr_t spe);
> +
> +int spe_mssync_status(spe_context_ptr_t spe);
> +
> +/*
>   * SPU SIgnal Notification Facility
>   */
>  int spe_signal_write (spe_context_ptr_t spe, unsigned int signal_reg, unsigned int data);
> 
> ===================================================================
> 
> Best regards, 
> 
> Gerhard Stenzel, Linux on Cell Development, LTC
> -------------------------------------------------------------------------------------
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