Re: [PATCH v1 2/6] dmaengine: dw-edma: Introduce helpers for getting the eDMA/HDMA max channel count

[Serge Semin]

On Fri, Jan 19, 2024 at 06:30:18PM +0530, Mrinmay Sarkar wrote:
> From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> 
> Add common helpers for getting the eDMA/HDMA max channel count.

See my comment to the patch 4:
https://lore.kernel.org/linux-pci/qfdsnz7louqdrs6mhz72o6mzjo66kw63vtlhgpz6hgqfyyzyhq@tge3r7mvwtw3/

-Serge(y)

> 
> Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> Signed-off-by: Mrinmay Sarkar <quic_msarkar@xxxxxxxxxxx>
> ---
>  drivers/dma/dw-edma/dw-edma-core.c           | 18 ++++++++++++++++++
>  drivers/pci/controller/dwc/pcie-designware.c |  6 +++---
>  include/linux/dma/edma.h                     | 14 ++++++++++++++
>  3 files changed, 35 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
> index 7fe1c19..2bd6e43 100644
> --- a/drivers/dma/dw-edma/dw-edma-core.c
> +++ b/drivers/dma/dw-edma/dw-edma-core.c
> @@ -902,6 +902,24 @@ static int dw_edma_irq_request(struct dw_edma *dw,
>  	return err;
>  }
>  
> +static u32 dw_edma_get_max_ch(enum dw_edma_map_format mf, enum dw_edma_dir dir)
> +{
> +	if (mf == EDMA_MF_HDMA_NATIVE)
> +		return HDMA_MAX_NR_CH;
> +
> +	return dir == EDMA_DIR_WRITE ? EDMA_MAX_WR_CH : EDMA_MAX_RD_CH;
> +}
> +
> +u32 dw_edma_get_max_rd_ch(enum dw_edma_map_format mf)
> +{
> +	return dw_edma_get_max_ch(mf, EDMA_DIR_READ);
> +}
> +
> +u32 dw_edma_get_max_wr_ch(enum dw_edma_map_format mf)
> +{
> +	return dw_edma_get_max_ch(mf, EDMA_DIR_WRITE);
> +}
> +
>  int dw_edma_probe(struct dw_edma_chip *chip)
>  {
>  	struct device *dev;
> diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c
> index eca047a..96575b8 100644
> --- a/drivers/pci/controller/dwc/pcie-designware.c
> +++ b/drivers/pci/controller/dwc/pcie-designware.c
> @@ -864,7 +864,7 @@ static int dw_pcie_edma_irq_vector(struct dw_edma_chip *edma, unsigned int nr)
>  	char name[6];
>  	int ret;
>  
> -	if (nr >= EDMA_MAX_WR_CH + EDMA_MAX_RD_CH)
> +	if (nr >= dw_edma_get_max_rd_ch(edma->mf) + dw_edma_get_max_wr_ch(edma->mf))
>  		return -EINVAL;
>  
>  	ret = platform_get_irq_byname_optional(pdev, "dma");
> @@ -923,8 +923,8 @@ static int dw_pcie_edma_find_chip(struct dw_pcie *pci)
>  	pci->edma.ll_rd_cnt = FIELD_GET(PCIE_DMA_NUM_RD_CHAN, val);
>  
>  	/* Sanity check the channels count if the mapping was incorrect */
> -	if (!pci->edma.ll_wr_cnt || pci->edma.ll_wr_cnt > EDMA_MAX_WR_CH ||
> -	    !pci->edma.ll_rd_cnt || pci->edma.ll_rd_cnt > EDMA_MAX_RD_CH)
> +	if (!pci->edma.ll_wr_cnt || pci->edma.ll_wr_cnt > dw_edma_get_max_wr_ch(pci->edma.mf) ||
> +	    !pci->edma.ll_rd_cnt || pci->edma.ll_rd_cnt > dw_edma_get_max_rd_ch(pci->edma.mf))
>  		return -EINVAL;
>  
>  	return 0;
> diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
> index 7197a58..550f6a4 100644
> --- a/include/linux/dma/edma.h
> +++ b/include/linux/dma/edma.h
> @@ -106,6 +106,9 @@ struct dw_edma_chip {
>  #if IS_REACHABLE(CONFIG_DW_EDMA)
>  int dw_edma_probe(struct dw_edma_chip *chip);
>  int dw_edma_remove(struct dw_edma_chip *chip);
> +
> +u32 dw_edma_get_max_rd_ch(enum dw_edma_map_format mf);
> +u32 dw_edma_get_max_wr_ch(enum dw_edma_map_format mf);
>  #else
>  static inline int dw_edma_probe(struct dw_edma_chip *chip)
>  {
> @@ -116,6 +119,17 @@ static inline int dw_edma_remove(struct dw_edma_chip *chip)
>  {
>  	return 0;
>  }
> +
> +static inline u32 dw_edma_get_max_rd_ch(enum dw_edma_map_format mf)
> +{
> +	return 0;
> +}
> +
> +static inline u32 dw_edma_get_max_wr_ch(enum dw_edma_map_format mf)
> +{
> +	return 0;
> +}
> +
>  #endif /* CONFIG_DW_EDMA */
>  
>  #endif /* _DW_EDMA_H */
> -- 
> 2.7.4
>