Re: [PATCH v5 1/2] dmaengine: Add context parameter to prep_dma_sg and prep_interleaved_dma

[Vinod Koul <vinod.koul@linux.intel.com>]

On Thu, 2012-03-22 at 19:52 +0530, Ravi Kumar V wrote:
> Add new context parameter to DMA SG and Interleaveid mode for passing
Typo					  ^^^^^^^^^^^^
> per transfer specific private data, using this it enables the
> dma devices which needs to pass the parameters which changes per
> each transfer
> 
> Signed-off-by: Ravi Kumar V <kumarrav@codeaurora.org>
> ---
>  drivers/dma/fsldma.c                    |    2 +-
>  drivers/dma/sirf-dma.c                  |    2 +-
>  drivers/dma/ste_dma40.c                 |    2 +-
>  drivers/misc/carma/carma-fpga-program.c |    2 +-
>  drivers/misc/carma/carma-fpga.c         |    7 +++----
>  include/linux/dmaengine.h               |   22 ++++++++++++++++++++--
>  6 files changed, 27 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
> index b98070c..f9f77db 100644
> --- a/drivers/dma/fsldma.c
> +++ b/drivers/dma/fsldma.c
> @@ -645,7 +645,7 @@ fail:
>  static struct dma_async_tx_descriptor *fsl_dma_prep_sg(struct dma_chan *dchan,
>  	struct scatterlist *dst_sg, unsigned int dst_nents,
>  	struct scatterlist *src_sg, unsigned int src_nents,
> -	unsigned long flags)
> +	unsigned long flags, void *context)
>  {
>  	struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL;
>  	struct fsldma_chan *chan = to_fsl_chan(dchan);
> diff --git a/drivers/dma/sirf-dma.c b/drivers/dma/sirf-dma.c
> index 2333810..ff4d344 100644
> --- a/drivers/dma/sirf-dma.c
> +++ b/drivers/dma/sirf-dma.c
> @@ -428,7 +428,7 @@ sirfsoc_dma_tx_status(struct dma_chan *chan, dma_cookie_t cookie,
>  
>  static struct dma_async_tx_descriptor *sirfsoc_dma_prep_interleaved(
>  	struct dma_chan *chan, struct dma_interleaved_template *xt,
> -	unsigned long flags)
> +	unsigned long flags, void *context)
>  {
>  	struct sirfsoc_dma *sdma = dma_chan_to_sirfsoc_dma(chan);
>  	struct sirfsoc_dma_chan *schan = dma_chan_to_sirfsoc_dma_chan(chan);
> diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
> index cc5ecbc..2f58ba9 100644
> --- a/drivers/dma/ste_dma40.c
> +++ b/drivers/dma/ste_dma40.c
> @@ -2287,7 +2287,7 @@ static struct dma_async_tx_descriptor *
>  d40_prep_memcpy_sg(struct dma_chan *chan,
>  		   struct scatterlist *dst_sg, unsigned int dst_nents,
>  		   struct scatterlist *src_sg, unsigned int src_nents,
> -		   unsigned long dma_flags)
> +		   unsigned long dma_flags, void *context)
>  {
>  	if (dst_nents != src_nents)
>  		return NULL;
> diff --git a/drivers/misc/carma/carma-fpga-program.c b/drivers/misc/carma/carma-fpga-program.c
> index a2d25e4..3739a12 100644
> --- a/drivers/misc/carma/carma-fpga-program.c
> +++ b/drivers/misc/carma/carma-fpga-program.c
> @@ -530,7 +530,7 @@ static noinline int fpga_program_dma(struct fpga_dev *priv)
>  	}
>  
>  	/* setup and submit the DMA transaction */
> -	tx = chan->device->device_prep_dma_sg(chan,
> +	tx = chan->device->dmaengine_prep_dma_sg(chan,
>  					      table.sgl, num_pages,
>  					      vb->sglist, vb->sglen, 0);
No the idea is that clients will not know anything about additionlay
parameter hence avoiding abuse. You need to reread the patches sent by
Alexandre.

You need to 
1) add wrappers over interleaved api which dont expose this additional
parameter
2) move existing users to use these wrappers
3) add a new API which has your additional argument (not an opaque
object) and this calls .device_xx callback with additional arg.
4. Above can be under conditional of your specific subsystem where these
parameters are valid.

>  	if (!tx) {
> diff --git a/drivers/misc/carma/carma-fpga.c b/drivers/misc/carma/carma-fpga.c
> index 14e974b2..be0baf6 100644
> --- a/drivers/misc/carma/carma-fpga.c
> +++ b/drivers/misc/carma/carma-fpga.c
> @@ -638,10 +638,9 @@ static int data_submit_dma(struct fpga_device *priv, struct data_buf *buf)
>  	 */
>  
>  	/* setup the scatterlist to scatterlist transfer */
> -	tx = chan->device->device_prep_dma_sg(chan,
> -					      dst_sg, dst_nents,
> -					      src_sg, src_nents,
> -					      0);
> +	tx = dmaengine_prep_dma_sg(chan, dst_sg, dst_nents,
> +					 src_sg, src_nents,
> +					 0);
>  	if (!tx) {
>  		dev_err(priv->dev, "unable to prep scatterlist DMA\n");
>  		return -ENOMEM;
> diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
> index 679b349..68a57da 100644
> --- a/include/linux/dmaengine.h
> +++ b/include/linux/dmaengine.h
> @@ -570,7 +570,7 @@ struct dma_device {
>  		struct dma_chan *chan,
>  		struct scatterlist *dst_sg, unsigned int dst_nents,
>  		struct scatterlist *src_sg, unsigned int src_nents,
> -		unsigned long flags);
> +		unsigned long flags, void *context);
>  
>  	struct dma_async_tx_descriptor *(*device_prep_slave_sg)(
>  		struct dma_chan *chan, struct scatterlist *sgl,
> @@ -581,7 +581,7 @@ struct dma_device {
>  		size_t period_len, enum dma_transfer_direction direction);
>  	struct dma_async_tx_descriptor *(*device_prep_interleaved_dma)(
>  		struct dma_chan *chan, struct dma_interleaved_template *xt,
> -		unsigned long flags);
> +		unsigned long flags, void *context);
>  	int (*device_control)(struct dma_chan *chan, enum dma_ctrl_cmd cmd,
>  		unsigned long arg);
>  
> @@ -615,6 +615,24 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_single(
>  	return chan->device->device_prep_slave_sg(chan, &sg, 1, dir, flags);
>  }
>  
> +static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_sg(
> +			struct dma_chan *chan, struct scatterlist *dst_sg,
> +			unsigned int dst_nents,	struct scatterlist *src_sg,
> +			unsigned int src_nents,	unsigned long flags)
> +{
> +	return chan->device->device_prep_dma_sg(chan, dst_sg, dst_nents,
> +					src_sg, src_nents, flags, NULL);
> +}
> +
> +static inline struct dma_async_tx_descriptor *dmaengine_prep_interleaved_dma(
> +			struct dma_chan *chan,
> +			struct dma_interleaved_template *xt,
> +			unsigned long flags)
> +{
> +	return chan->device->device_prep_interleaved_dma(chan, xt,
> +							flags, NULL);
> +}
> +
>  static inline int dmaengine_terminate_all(struct dma_chan *chan)
>  {
>  	return dmaengine_device_control(chan, DMA_TERMINATE_ALL, 0);


-- 
~Vinod