Re: [PATCH v6] dmaengine: dw-edma: Enable HDMA 64R/W Channels

[Frank Li <Frank.li@oss.nxp.com>]

On Mon, Jul 06, 2026 at 06:03:26PM +0530, Devendra K Verma wrote:
> As per 'Designware Cores PCI Express Controller Databook',
> Section 7.1 - Overview, HDMA supports 64 Read and 64 Write
> channels. Current controller driver supports up to 8 read and
> write channels only. In order to utilize all the channels the
> controller driver need to have the channel related structs
> and variables as per the number of channels supported by IP.
> Following changes are made to enable 64 Read / 64 Write
> channel support:
>
>  o Defined HDMA specific macros to reflect the channel count.
>  o The count of ll_regions and dt_regions in dw_edma_chip and
>    dw_edma_pcie_data shall be in accordance to number of read
>    and write channels.
>  o In dw_edma_probe() configure the channels as per the channels
>    of the IP used.
>  o Changed mask types to u64 for higher channel counts.
>
> Signed-off-by: Devendra K Verma <devendra.verma@amd.com>
> ---
...
>  struct dw_edma_irq {
>  	struct msi_msg                  msi;
> -	u32				wr_mask;
> -	u32				rd_mask;
>  	struct dw_edma			*dw;
> +
> +	DECLARE_BITMAP(wr_mask, 64);
> +	DECLARE_BITMAP(rd_mask, 64);

Nit: Please macro HDMA_MAX_RD_CH and HDMA_MAX_WD_CH

>  };
>
...
> @@ -252,7 +252,7 @@ dw_edma_v0_core_handle_int(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir,
>  	}
>
>  	val = dw_edma_v0_core_status_done_int(dw, dir);
> -	val &= mask;
> +	val &= *mask;
>  	for_each_set_bit(pos, &val, total) {
>  		chan = &dw->chan[pos + off];
>
> @@ -263,7 +263,7 @@ dw_edma_v0_core_handle_int(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir,
>  	}
>
>  	val = dw_edma_v0_core_status_abort_int(dw, dir);
> -	val &= mask;
> +	val &= *mask;

It should be fine if sparse don't report warning.

Frank

>  	for_each_set_bit(pos, &val, total) {
>  		chan = &dw->chan[pos + off];
>
> diff --git a/drivers/dma/dw-edma/dw-hdma-v0-core.c b/drivers/dma/dw-edma/dw-hdma-v0-core.c
> index 632abb8b481c..0181bd276e22 100644
> --- a/drivers/dma/dw-edma/dw-hdma-v0-core.c
> +++ b/drivers/dma/dw-edma/dw-hdma-v0-core.c
> @@ -53,13 +53,24 @@ __dw_ch_regs(struct dw_edma *dw, enum dw_edma_dir dir, u16 ch)
>  static void dw_hdma_v0_core_off(struct dw_edma *dw)
>  {
>  	int id;
> +	enum dw_edma_dir dir;
> +/HDMA_MAX_RD_CH

> +	dir = EDMA_DIR_WRITE;
> +	for (id = 0; id < dw->wr_ch_cnt; id++) {
> +		SET_CH_32(dw, dir, id, int_setup,
> +			  HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK);
> +		SET_CH_32(dw, dir, id, int_clear,
> +			  HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK);
> +		SET_CH_32(dw, dir, id, ch_en, 0);
> +	}
>
> -	for (id = 0; id < HDMA_V0_MAX_NR_CH; id++) {
> -		SET_BOTH_CH_32(dw, id, int_setup,
> -			       HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK);
> -		SET_BOTH_CH_32(dw, id, int_clear,
> -			       HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK);
> -		SET_BOTH_CH_32(dw, id, ch_en, 0);
> +	dir = EDMA_DIR_READ;
> +	for (id = 0; id < dw->rd_ch_cnt; id++) {
> +		SET_CH_32(dw, dir, id, int_setup,
> +			  HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK);
> +		SET_CH_32(dw, dir, id, int_clear,
> +			  HDMA_V0_STOP_INT_MASK | HDMA_V0_ABORT_INT_MASK);
> +		SET_CH_32(dw, dir, id, ch_en, 0);
>  	}
>  }
>
> @@ -118,7 +129,7 @@ dw_hdma_v0_core_handle_int(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir,
>  	unsigned long total, pos, val;
>  	irqreturn_t ret = IRQ_NONE;
>  	struct dw_edma_chan *chan;
> -	unsigned long off, mask;
> +	unsigned long off, *mask;
>
>  	if (dir == EDMA_DIR_WRITE) {
>  		total = dw->wr_ch_cnt;
> @@ -130,7 +141,7 @@ dw_hdma_v0_core_handle_int(struct dw_edma_irq *dw_irq, enum dw_edma_dir dir,
>  		mask = dw_irq->rd_mask;
>  	}
>
> -	for_each_set_bit(pos, &mask, total) {
> +	for_each_set_bit(pos, mask, total) {
>  		chan = &dw->chan[pos + off];
>
>  		val = dw_hdma_v0_core_status_int(chan);
> diff --git a/drivers/dma/dw-edma/dw-hdma-v0-regs.h b/drivers/dma/dw-edma/dw-hdma-v0-regs.h
> index 7759ba9b4850..48e40efceb2e 100644
> --- a/drivers/dma/dw-edma/dw-hdma-v0-regs.h
> +++ b/drivers/dma/dw-edma/dw-hdma-v0-regs.h
> @@ -11,7 +11,7 @@
>
>  #include <linux/dmaengine.h>
>
> -#define HDMA_V0_MAX_NR_CH			8
> +#define HDMA_V0_MAX_NR_CH			64
>  #define HDMA_V0_CH_EN				BIT(0)
>  #define HDMA_V0_LOCAL_ABORT_INT_EN		BIT(6)
>  #define HDMA_V0_REMOTE_ABORT_INT_EN		BIT(5)
> diff --git a/include/linux/dma/edma.h b/include/linux/dma/edma.h
> index 1fafd5b0e315..da7a5cc93ad4 100644
> --- a/include/linux/dma/edma.h
> +++ b/include/linux/dma/edma.h
> @@ -14,6 +14,8 @@
>
>  #define EDMA_MAX_WR_CH                                  8
>  #define EDMA_MAX_RD_CH                                  8
> +#define HDMA_MAX_WR_CH                                  64
> +#define HDMA_MAX_RD_CH                                  64
>
>  struct dw_edma;
>
> @@ -89,12 +91,12 @@ struct dw_edma_chip {
>  	u16			ll_wr_cnt;
>  	u16			ll_rd_cnt;
>  	/* link list address */
> -	struct dw_edma_region	ll_region_wr[EDMA_MAX_WR_CH];
> -	struct dw_edma_region	ll_region_rd[EDMA_MAX_RD_CH];
> +	struct dw_edma_region	ll_region_wr[HDMA_MAX_WR_CH];
> +	struct dw_edma_region	ll_region_rd[HDMA_MAX_RD_CH];
>
>  	/* data region */
> -	struct dw_edma_region	dt_region_wr[EDMA_MAX_WR_CH];
> -	struct dw_edma_region	dt_region_rd[EDMA_MAX_RD_CH];
> +	struct dw_edma_region	dt_region_wr[HDMA_MAX_WR_CH];
> +	struct dw_edma_region	dt_region_rd[HDMA_MAX_RD_CH];
>
>  	/* interrupt emulation */
>  	int			db_irq;
> --
> 2.43.0
>