Re: [PATCH 1/2] dmaengine: Move icg helpers to global header

From: Ludovic Desroches
Date: Mon Jun 01 2015 - 04:14:06 EST


On Wed, May 27, 2015 at 04:01:52PM +0200, Maxime Ripard wrote:
> Now that we can have ICGs set for both the source and destination (using
> the icg field of struct data_chunk) or for only the source or the
> destination (using the dst_icg or src_icg respectively), and that these
> fields can be ignored depending on other parameters (src_inc, src_sgl,
> etc.), the logic to get the actual ICG value can be quite tricky.
>
> The XDMAC driver was already implementing it, but since we will need it in
> other drivers, we can move it to the main header file.
>
> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
Acked-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx>

> ---
> drivers/dma/at_xdmac.c | 46 ++++------------------------------------------
> include/linux/dmaengine.h | 27 +++++++++++++++++++++++++++
> 2 files changed, 31 insertions(+), 42 deletions(-)
>
> diff --git a/drivers/dma/at_xdmac.c b/drivers/dma/at_xdmac.c
> index 9b602a67d40d..80e46e571bdd 100644
> --- a/drivers/dma/at_xdmac.c
> +++ b/drivers/dma/at_xdmac.c
> @@ -862,20 +862,8 @@ at_xdmac_interleaved_queue_desc(struct dma_chan *chan,
>
> desc->lld.mbr_sa = src;
> desc->lld.mbr_da = dst;
> -
> - if (xt->src_inc && xt->src_sgl) {
> - if (chunk->src_icg)
> - desc->lld.mbr_sus = chunk->src_icg;
> - else
> - desc->lld.mbr_sus = chunk->icg;
> - }
> -
> - if (xt->dst_inc && xt->dst_sgl) {
> - if (chunk->dst_icg)
> - desc->lld.mbr_dus = chunk->dst_icg;
> - else
> - desc->lld.mbr_dus = chunk->icg;
> - }
> + desc->lld.mbr_sus = dmaengine_get_src_icg(xt, chunk);
> + desc->lld.mbr_dus = dmaengine_get_dst_icg(xt, chunk);
>
> desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV3
> | AT_XDMAC_MBR_UBC_NDEN
> @@ -895,32 +883,6 @@ at_xdmac_interleaved_queue_desc(struct dma_chan *chan,
> return desc;
> }
>
> -static size_t at_xdmac_get_icg(bool inc, bool sgl, size_t icg, size_t dir_icg)
> -{
> - if (inc) {
> - if (dir_icg)
> - return dir_icg;
> - else if (sgl)
> - return icg;
> - }
> -
> - return 0;
> -}
> -
> -static size_t at_xdmac_get_dst_icg(struct dma_interleaved_template *xt,
> - struct data_chunk *chunk)
> -{
> - return at_xdmac_get_icg(xt->dst_inc, xt->dst_sgl,
> - chunk->icg, chunk->dst_icg);
> -}
> -
> -static size_t at_xdmac_get_src_icg(struct dma_interleaved_template *xt,
> - struct data_chunk *chunk)
> -{
> - return at_xdmac_get_icg(xt->src_inc, xt->src_sgl,
> - chunk->icg, chunk->src_icg);
> -}
> -
> static struct dma_async_tx_descriptor *
> at_xdmac_prep_interleaved(struct dma_chan *chan,
> struct dma_interleaved_template *xt,
> @@ -950,8 +912,8 @@ at_xdmac_prep_interleaved(struct dma_chan *chan,
>
> chunk = xt->sgl + i;
>
> - dst_icg = at_xdmac_get_dst_icg(xt, chunk);
> - src_icg = at_xdmac_get_src_icg(xt, chunk);
> + dst_icg = dmaengine_get_dst_icg(xt, chunk);
> + src_icg = dmaengine_get_src_icg(xt, chunk);
>
> src_skip = chunk->size + src_icg;
> dst_skip = chunk->size + dst_icg;
> diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
> index 8faf6a2dd9d8..43a9a397b2d7 100644
> --- a/include/linux/dmaengine.h
> +++ b/include/linux/dmaengine.h
> @@ -899,6 +899,33 @@ static inline int dma_maxpq(struct dma_device *dma, enum dma_ctrl_flags flags)
> BUG();
> }
>
> +static inline size_t dmaengine_get_icg(bool inc, bool sgl, size_t icg,
> + size_t dir_icg)
> +{
> + if (inc) {
> + if (dir_icg)
> + return dir_icg;
> + else if (sgl)
> + return icg;
> + }
> +
> + return 0;
> +}
> +
> +static inline size_t dmaengine_get_dst_icg(struct dma_interleaved_template *xt,
> + struct data_chunk *chunk)
> +{
> + return dmaengine_get_icg(xt->dst_inc, xt->dst_sgl,
> + chunk->icg, chunk->dst_icg);
> +}
> +
> +static inline size_t dmaengine_get_src_icg(struct dma_interleaved_template *xt,
> + struct data_chunk *chunk)
> +{
> + return dmaengine_get_icg(xt->src_inc, xt->src_sgl,
> + chunk->icg, chunk->src_icg);
> +}
> +
> /* --- public DMA engine API --- */
>
> #ifdef CONFIG_DMA_ENGINE
> --
> 2.4.1
>
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