RE: [PATCH V3 1/1] dmaengine: fsl-edma: support edma memcpy

[Joy Zou]

-----Original Message-----
From: Robin Gong <yibin.gong@xxxxxxx> 
Sent: 2021年10月25日 13:49
To: Joy Zou <joy.zou@xxxxxxx>; vkoul@xxxxxxxxxx
Cc: dmaengine@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: RE: [PATCH V3 1/1] dmaengine: fsl-edma: support edma memcpy

On 2021/10/19 14:26 Joy Zou <joy.zou@xxxxxxx> wrote:
> Add memcpy in edma. The edma has the capability to transfer data by 
> software trigger so that it could be used for memory copy. Enable 
> MEMCPY for edma driver and it could be test directly by dmatest.
> 
> Signed-off-by: Joy Zou <joy.zou@xxxxxxx>
> ---
> Changes since (implicit) v2:
> Remove 'Reported-by' tag in v3.
> Robot report sparse warning on v1, fixed it in v2.
> Add blank line in v3.
> Add commit message in v3.
> ---
>  drivers/dma/fsl-edma-common.c | 34 ++++++++++++++++++++++++++++++++--
>  drivers/dma/fsl-edma-common.h |  4 ++++
>  drivers/dma/fsl-edma.c        |  7 +++++++
>  3 files changed, 43 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/dma/fsl-edma-common.c 
> b/drivers/dma/fsl-edma-common.c index 930ae268c497..3f7c9faa8c9a
> 100644
> --- a/drivers/dma/fsl-edma-common.c
> +++ b/drivers/dma/fsl-edma-common.c
> @@ -343,11 +343,11 @@ enum dma_status fsl_edma_tx_status(struct 
> dma_chan *chan,  EXPORT_SYMBOL_GPL(fsl_edma_tx_status);
> 
>  static void fsl_edma_set_tcd_regs(struct fsl_edma_chan *fsl_chan,
> -				  struct fsl_edma_hw_tcd *tcd)
> -{
> +				  struct fsl_edma_hw_tcd *tcd){
Seems no any change here, please ensure no any code difference accordingly.
Ok, may be a misoperation.
>  	struct fsl_edma_engine *edma = fsl_chan->edma;
>  	struct edma_regs *regs = &fsl_chan->edma->regs;
>  	u32 ch = fsl_chan->vchan.chan.chan_id;
> +	u16 csr = 0;
> 
>  	/*
>  	 * TCD parameters are stored in struct fsl_edma_hw_tcd in little @@
> -373,6 +373,12 @@ static void fsl_edma_set_tcd_regs(struct 
> fsl_edma_chan *fsl_chan,
>  	edma_writel(edma, (s32)tcd->dlast_sga,
>  			&regs->tcd[ch].dlast_sga);
> 
> +	if (fsl_chan->is_sw) {
> +		csr = le16_to_cpu(tcd->csr);
> +		csr |= EDMA_TCD_CSR_START;
> +		tcd->csr = cpu_to_le16(csr);
> +	}
> +
>  	edma_writew(edma, (s16)tcd->csr, &regs->tcd[ch].csr);  }
> 
> @@ -587,6 +593,29 @@ struct dma_async_tx_descriptor 
> *fsl_edma_prep_slave_sg(  } EXPORT_SYMBOL_GPL(fsl_edma_prep_slave_sg);
> 
> +struct dma_async_tx_descriptor *fsl_edma_prep_memcpy(
> +		struct dma_chan *chan, dma_addr_t dma_dst,
> +		dma_addr_t dma_src, size_t len, unsigned long flags) {
> +	struct fsl_edma_chan *fsl_chan = to_fsl_edma_chan(chan);
> +	struct fsl_edma_desc *fsl_desc;
> +
> +	fsl_desc = fsl_edma_alloc_desc(fsl_chan, 1);
> +	if (!fsl_desc)
> +		return NULL;
> +	fsl_desc->iscyclic = false;
> +
> +	fsl_chan->is_sw = true;
> +
> +	/* To match with copy_align and max_seg_size so 1 tcd is enough */
> +	fsl_edma_fill_tcd(fsl_desc->tcd[0].vtcd, dma_src, dma_dst,
> +			EDMA_TCD_ATTR_SSIZE_32BYTE |
> EDMA_TCD_ATTR_DSIZE_32BYTE,
> +			32, len, 0, 1, 1, 32, 0, true, true, false);
> +
> +	return vchan_tx_prep(&fsl_chan->vchan, &fsl_desc->vdesc, flags); } 
> +EXPORT_SYMBOL_GPL(fsl_edma_prep_memcpy);
> +
>  void fsl_edma_xfer_desc(struct fsl_edma_chan *fsl_chan)  {
>  	struct virt_dma_desc *vdesc;
> @@ -652,6 +681,7 @@ void fsl_edma_free_chan_resources(struct dma_chan
> *chan)
>  	vchan_dma_desc_free_list(&fsl_chan->vchan, &head);
>  	dma_pool_destroy(fsl_chan->tcd_pool);
>  	fsl_chan->tcd_pool = NULL;
> +	fsl_chan->is_sw = false;
>  }
>  EXPORT_SYMBOL_GPL(fsl_edma_free_chan_resources);
> 
> diff --git a/drivers/dma/fsl-edma-common.h 
> b/drivers/dma/fsl-edma-common.h index ec1169741de1..004ec4a6bc86
> 100644
> --- a/drivers/dma/fsl-edma-common.h
> +++ b/drivers/dma/fsl-edma-common.h
> @@ -121,6 +121,7 @@ struct fsl_edma_chan {
>  	struct fsl_edma_desc		*edesc;
>  	struct dma_slave_config		cfg;
>  	u32				attr;
> +	bool                            is_sw;
>  	struct dma_pool			*tcd_pool;
>  	dma_addr_t			dma_dev_addr;
>  	u32				dma_dev_size;
> @@ -240,6 +241,9 @@ struct dma_async_tx_descriptor 
> *fsl_edma_prep_slave_sg(
>  		struct dma_chan *chan, struct scatterlist *sgl,
>  		unsigned int sg_len, enum dma_transfer_direction direction,
>  		unsigned long flags, void *context);
> +struct dma_async_tx_descriptor *fsl_edma_prep_memcpy(
> +		struct dma_chan *chan, dma_addr_t dma_dst, dma_addr_t dma_src,
> +		size_t len, unsigned long flags);
>  void fsl_edma_xfer_desc(struct fsl_edma_chan *fsl_chan);  void 
> fsl_edma_issue_pending(struct dma_chan *chan);  int 
> fsl_edma_alloc_chan_resources(struct dma_chan *chan); diff --git 
> a/drivers/dma/fsl-edma.c b/drivers/dma/fsl-edma.c index
> 90bb72af306c..76cbf54aec58 100644
> --- a/drivers/dma/fsl-edma.c
> +++ b/drivers/dma/fsl-edma.c
> @@ -17,6 +17,7 @@
>  #include <linux/of_address.h>
>  #include <linux/of_irq.h>
>  #include <linux/of_dma.h>
> +#include <linux/dma-mapping.h>
> 
>  #include "fsl-edma-common.h"
> 
> @@ -372,6 +373,7 @@ static int fsl_edma_probe(struct platform_device
> *pdev)
>  	dma_cap_set(DMA_PRIVATE, fsl_edma->dma_dev.cap_mask);
>  	dma_cap_set(DMA_SLAVE, fsl_edma->dma_dev.cap_mask);
>  	dma_cap_set(DMA_CYCLIC, fsl_edma->dma_dev.cap_mask);
> +	dma_cap_set(DMA_MEMCPY, fsl_edma->dma_dev.cap_mask);
> 
>  	fsl_edma->dma_dev.dev = &pdev->dev;
>  	fsl_edma->dma_dev.device_alloc_chan_resources
> @@ -381,6 +383,7 @@ static int fsl_edma_probe(struct platform_device
> *pdev)
>  	fsl_edma->dma_dev.device_tx_status = fsl_edma_tx_status;
>  	fsl_edma->dma_dev.device_prep_slave_sg = fsl_edma_prep_slave_sg;
>  	fsl_edma->dma_dev.device_prep_dma_cyclic = fsl_edma_prep_dma_cyclic;
> +	fsl_edma->dma_dev.device_prep_dma_memcpy =
> fsl_edma_prep_memcpy;
>  	fsl_edma->dma_dev.device_config = fsl_edma_slave_config;
>  	fsl_edma->dma_dev.device_pause = fsl_edma_pause;
>  	fsl_edma->dma_dev.device_resume = fsl_edma_resume; @@ -392,6
> +395,10 @@ static int fsl_edma_probe(struct platform_device *pdev)
>  	fsl_edma->dma_dev.dst_addr_widths = FSL_EDMA_BUSWIDTHS;
>  	fsl_edma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | 
> BIT(DMA_MEM_TO_DEV);
> 
> +	fsl_edma->dma_dev.copy_align = DMAENGINE_ALIGN_32_BYTES;
> +	/* Per worst case 'nbytes = 1' take CITER as the max_seg_size */
> +	dma_set_max_seg_size(fsl_edma->dma_dev.dev, 0x3fff);
> +
>  	platform_set_drvdata(pdev, fsl_edma);
> 
>  	ret = dma_async_device_register(&fsl_edma->dma_dev);
> --
> 2.25.1