Re: [PATCH] dmaengine: use assign_bit() where applicable

[Dave Jiang]

On 9/18/26 7:16 AM, Peng Fan (OSS) wrote:
> From: Peng Fan <peng.fan@xxxxxxx>
> 
> Convert open-coded if/else with set_bit/clear_bit and their
> non-atomic __set_bit/__clear_bit variants to the assign_bit/__assign_bit
> API.
> 
> Done with Coccinelle semantic patch.
> 
> Signed-off-by: Peng Fan <peng.fan@xxxxxxx>

Reviewed-by: Dave Jiang <dave.jiang@xxxxxxxxx>

> ---
>  drivers/dma/idxd/sysfs.c  |  5 +----
>  drivers/dma/imx-sdma.c    | 15 +++------------
>  drivers/dma/ppc4xx/adma.c | 29 +++++++++--------------------
>  3 files changed, 13 insertions(+), 36 deletions(-)
> 
> diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
> index 6d251095c350..2b0524324089 100644
> --- a/drivers/dma/idxd/sysfs.c
> +++ b/drivers/dma/idxd/sysfs.c
> @@ -1095,10 +1095,7 @@ static ssize_t wq_ats_disable_store(struct device *dev, struct device_attribute
>  	if (rc < 0)
>  		return rc;
>  
> -	if (ats_dis)
> -		set_bit(WQ_FLAG_ATS_DISABLE, &wq->flags);
> -	else
> -		clear_bit(WQ_FLAG_ATS_DISABLE, &wq->flags);
> +	assign_bit(WQ_FLAG_ATS_DISABLE, &wq->flags, ats_dis);
>  
>  	return count;
>  }
> diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
> index 36368835a845..b8a91a0343b5 100644
> --- a/drivers/dma/imx-sdma.c
> +++ b/drivers/dma/imx-sdma.c
> @@ -710,20 +710,11 @@ static int sdma_config_ownership(struct sdma_channel *sdmac,
>  	mcu = readl_relaxed(sdma->regs + SDMA_H_HOSTOVR);
>  	dsp = readl_relaxed(sdma->regs + SDMA_H_DSPOVR);
>  
> -	if (dsp_override)
> -		__clear_bit(channel, &dsp);
> -	else
> -		__set_bit(channel, &dsp);
> +	__assign_bit(channel, &dsp, !dsp_override);
>  
> -	if (event_override)
> -		__clear_bit(channel, &evt);
> -	else
> -		__set_bit(channel, &evt);
> +	__assign_bit(channel, &evt, !event_override);
>  
> -	if (mcu_override)
> -		__clear_bit(channel, &mcu);
> -	else
> -		__set_bit(channel, &mcu);
> +	__assign_bit(channel, &mcu, !mcu_override);
>  
>  	writel_relaxed(evt, sdma->regs + SDMA_H_EVTOVR);
>  	writel_relaxed(mcu, sdma->regs + SDMA_H_HOSTOVR);
> diff --git a/drivers/dma/ppc4xx/adma.c b/drivers/dma/ppc4xx/adma.c
> index 279a431ccae3..39b1c4fd9ca5 100644
> --- a/drivers/dma/ppc4xx/adma.c
> +++ b/drivers/dma/ppc4xx/adma.c
> @@ -350,10 +350,8 @@ static void ppc440spe_desc_init_dma01pq(struct ppc440spe_adma_desc_slot *desc,
>  			 * of the transaction (src, dst, ...)
>  			 */
>  			iter->hw_next = NULL;
> -			if (flags & DMA_PREP_INTERRUPT)
> -				set_bit(PPC440SPE_DESC_INT, &iter->flags);
> -			else
> -				clear_bit(PPC440SPE_DESC_INT, &iter->flags);
> +			assign_bit(PPC440SPE_DESC_INT, &iter->flags,
> +				   flags & DMA_PREP_INTERRUPT);
>  		}
>  	}
>  
> @@ -508,10 +506,7 @@ static void ppc440spe_desc_init_memcpy(struct ppc440spe_adma_desc_slot *desc,
>  	desc->src_cnt = 1;
>  	desc->dst_cnt = 1;
>  
> -	if (flags & DMA_PREP_INTERRUPT)
> -		set_bit(PPC440SPE_DESC_INT, &desc->flags);
> -	else
> -		clear_bit(PPC440SPE_DESC_INT, &desc->flags);
> +	assign_bit(PPC440SPE_DESC_INT, &desc->flags, flags & DMA_PREP_INTERRUPT);
>  
>  	hw_desc->opc = DMA_CDB_OPC_MV_SG1_SG2;
>  }
> @@ -2136,10 +2131,8 @@ static struct ppc440spe_adma_desc_slot *ppc440spe_dma01_prep_mult(
>  					chain_node);
>  		memset(iter->hw_desc, 0, sizeof(struct dma_cdb));
>  		iter->hw_next = NULL;
> -		if (flags & DMA_PREP_INTERRUPT)
> -			set_bit(PPC440SPE_DESC_INT, &iter->flags);
> -		else
> -			clear_bit(PPC440SPE_DESC_INT, &iter->flags);
> +		assign_bit(PPC440SPE_DESC_INT, &iter->flags,
> +			   flags & DMA_PREP_INTERRUPT);
>  
>  		hw_desc = iter->hw_desc;
>  		hw_desc->opc = DMA_CDB_OPC_MV_SG1_SG2;
> @@ -2221,10 +2214,8 @@ static struct ppc440spe_adma_desc_slot *ppc440spe_dma01_prep_sum_product(
>  		iter->hw_next = list_entry(iter->chain_node.next,
>  					   struct ppc440spe_adma_desc_slot,
>  					   chain_node);
> -		if (flags & DMA_PREP_INTERRUPT)
> -			set_bit(PPC440SPE_DESC_INT, &iter->flags);
> -		else
> -			clear_bit(PPC440SPE_DESC_INT, &iter->flags);
> +		assign_bit(PPC440SPE_DESC_INT, &iter->flags,
> +			   flags & DMA_PREP_INTERRUPT);
>  
>  		hw_desc = iter->hw_desc;
>  		hw_desc->opc = DMA_CDB_OPC_MV_SG1_SG2;
> @@ -2246,10 +2237,8 @@ static struct ppc440spe_adma_desc_slot *ppc440spe_dma01_prep_sum_product(
>  					chain_node);
>  		memset(iter->hw_desc, 0, sizeof(struct dma_cdb));
>  		iter->hw_next = NULL;
> -		if (flags & DMA_PREP_INTERRUPT)
> -			set_bit(PPC440SPE_DESC_INT, &iter->flags);
> -		else
> -			clear_bit(PPC440SPE_DESC_INT, &iter->flags);
> +		assign_bit(PPC440SPE_DESC_INT, &iter->flags,
> +			   flags & DMA_PREP_INTERRUPT);
>  
>  		hw_desc = iter->hw_desc;
>  		hw_desc->opc = DMA_CDB_OPC_MV_SG1_SG2;