[PATCH v2 0/2] dmaengine: hdmac: Add scatter-gathered memset support

[PATCH v2 0/2] dmaengine: hdmac: Add scatter-gathered memset support

[Maxime Ripard]

Hi Vinod,

Here is a patch serie that adds support in the Atmel HDMAC for memset
over a discontiguous memory area.

Just like for the memset, it's used on those SoCs to support
framebuffer related operations that cannot be performed either by the
display engine or the (non-existent) GPU.

Let me know what you think,
Maxime

Changes from v1:
  - Cosmetic change in the first patch to not wrap a line anymore
  - Rebased on top of current dma/next

Maxime Ripard (2):
  dmaengine: hdmac: factorise memset descriptor allocation
  dmaengine: hdmac: Add scatter-gathered memset support

 drivers/dma/at_hdmac.c      | 168 ++++++++++++++++++++++++++++++++++----------
 drivers/dma/at_hdmac_regs.h |   2 +-
 2 files changed, 133 insertions(+), 37 deletions(-)

-- 
2.6.2

[PATCH v2 0/2] dmaengine: hdmac: Add scatter-gathered memset support

[Maxime Ripard]

Hi Vinod,

Here is a patch serie that adds support in the Atmel HDMAC for memset
over a discontiguous memory area.

Just like for the memset, it's used on those SoCs to support
framebuffer related operations that cannot be performed either by the
display engine or the (non-existent) GPU.

Let me know what you think,
Maxime

Changes from v1:
  - Cosmetic change in the first patch to not wrap a line anymore
  - Rebased on top of current dma/next

Maxime Ripard (2):
  dmaengine: hdmac: factorise memset descriptor allocation
  dmaengine: hdmac: Add scatter-gathered memset support

 drivers/dma/at_hdmac.c      | 168 ++++++++++++++++++++++++++++++++++----------
 drivers/dma/at_hdmac_regs.h |   2 +-
 2 files changed, 133 insertions(+), 37 deletions(-)

-- 
2.6.2

[PATCH v2 1/2] dmaengine: hdmac: factorise memset descriptor allocation

[Maxime Ripard]

The memset and scatter gathered memset are going to use some common logic
to create their descriptors.

Move that logic into a function of its own so that we can share it with the
future memset_sg callback.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/dma/at_hdmac.c      | 97 ++++++++++++++++++++++++++-------------------
 drivers/dma/at_hdmac_regs.h |  2 +-
 2 files changed, 58 insertions(+), 41 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 58d406230d89..cad18f3660ae 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -458,10 +458,10 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
 		dma_cookie_complete(txd);
 
 	/* If the transfer was a memset, free our temporary buffer */
-	if (desc->memset) {
+	if (desc->memset_buffer) {
 		dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
 			      desc->memset_paddr);
-		desc->memset = false;
+		desc->memset_buffer = false;
 	}
 
 	/* move children to free_list */
@@ -881,6 +881,46 @@ err_desc_get:
 	return NULL;
 }
 
+static struct at_desc *atc_create_memset_desc(struct dma_chan *chan,
+					      dma_addr_t psrc,
+					      dma_addr_t pdst,
+					      size_t len)
+{
+	struct at_dma_chan *atchan = to_at_dma_chan(chan);
+	struct at_desc *desc;
+	size_t xfer_count;
+
+	u32 ctrla = ATC_SRC_WIDTH(2) | ATC_DST_WIDTH(2);
+	u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
+		ATC_SRC_ADDR_MODE_FIXED |
+		ATC_DST_ADDR_MODE_INCR |
+		ATC_FC_MEM2MEM;
+
+	xfer_count = len >> 2;
+	if (xfer_count > ATC_BTSIZE_MAX) {
+		dev_err(chan2dev(chan), "%s: buffer is too big\n",
+			__func__);
+		return NULL;
+	}
+
+	desc = atc_desc_get(atchan);
+	if (!desc) {
+		dev_err(chan2dev(chan), "%s: can't get a descriptor\n",
+			__func__);
+		return NULL;
+	}
+
+	desc->lli.saddr = psrc;
+	desc->lli.daddr = pdst;
+	desc->lli.ctrla = ctrla | xfer_count;
+	desc->lli.ctrlb = ctrlb;
+
+	desc->txd.cookie = 0;
+	desc->len = len;
+
+	return desc;
+}
+
 /**
  * atc_prep_dma_memset - prepare a memcpy operation
  * @chan: the channel to prepare operation on
@@ -893,12 +933,10 @@ static struct dma_async_tx_descriptor *
 atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
 		    size_t len, unsigned long flags)
 {
-	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
 	struct at_dma		*atdma = to_at_dma(chan->device);
-	struct at_desc		*desc = NULL;
-	size_t			xfer_count;
-	u32			ctrla;
-	u32			ctrlb;
+	struct at_desc		*desc;
+	void __iomem		*vaddr;
+	dma_addr_t		paddr;
 
 	dev_vdbg(chan2dev(chan), "%s: d0x%x v0x%x l0x%zx f0x%lx\n", __func__,
 		dest, value, len, flags);
@@ -914,46 +952,26 @@ atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
 		return NULL;
 	}
 
-	xfer_count = len >> 2;
-	if (xfer_count > ATC_BTSIZE_MAX) {
-		dev_err(chan2dev(chan), "%s: buffer is too big\n",
+	vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr);
+	if (!vaddr) {
+		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
 			__func__);
 		return NULL;
 	}
+	*(u32*)vaddr = value;
 
-	ctrlb =   ATC_DEFAULT_CTRLB | ATC_IEN
-		| ATC_SRC_ADDR_MODE_FIXED
-		| ATC_DST_ADDR_MODE_INCR
-		| ATC_FC_MEM2MEM;
-
-	ctrla = ATC_SRC_WIDTH(2) |
-		ATC_DST_WIDTH(2);
-
-	desc = atc_desc_get(atchan);
+	desc = atc_create_memset_desc(chan, paddr, dest, len);
 	if (!desc) {
-		dev_err(chan2dev(chan), "%s: can't get a descriptor\n",
+		dev_err(chan2dev(chan), "%s: couldn't get a descriptor\n",
 			__func__);
-		return NULL;
+		goto err_free_buffer;
 	}
 
-	desc->memset_vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC,
-					    &desc->memset_paddr);
-	if (!desc->memset_vaddr) {
-		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
-			__func__);
-		goto err_put_desc;
-	}
-
-	*desc->memset_vaddr = value;
-	desc->memset = true;
-
-	desc->lli.saddr = desc->memset_paddr;
-	desc->lli.daddr = dest;
-	desc->lli.ctrla = ctrla | xfer_count;
-	desc->lli.ctrlb = ctrlb;
+	desc->memset_paddr = paddr;
+	desc->memset_vaddr = vaddr;
+	desc->memset_buffer = true;
 
 	desc->txd.cookie = -EBUSY;
-	desc->len = len;
 	desc->total_len = len;
 
 	/* set end-of-link on the descriptor */
@@ -963,12 +981,11 @@ atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
 
 	return &desc->txd;
 
-err_put_desc:
-	atc_desc_put(atchan, desc);
+err_free_buffer:
+	dma_pool_free(atdma->memset_pool, vaddr, paddr);
 	return NULL;
 }
 
-
 /**
  * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
  * @chan: DMA channel
diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h
index c3bebbe899ac..d1cfc8c876f9 100644
--- a/drivers/dma/at_hdmac_regs.h
+++ b/drivers/dma/at_hdmac_regs.h
@@ -202,7 +202,7 @@ struct at_desc {
 	size_t				src_hole;
 
 	/* Memset temporary buffer */
-	bool				memset;
+	bool				memset_buffer;
 	dma_addr_t			memset_paddr;
 	int				*memset_vaddr;
 };
-- 
2.6.2

[PATCH v2 1/2] dmaengine: hdmac: factorise memset descriptor allocation

[Maxime Ripard]

The memset and scatter gathered memset are going to use some common logic
to create their descriptors.

Move that logic into a function of its own so that we can share it with the
future memset_sg callback.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/dma/at_hdmac.c      | 97 ++++++++++++++++++++++++++-------------------
 drivers/dma/at_hdmac_regs.h |  2 +-
 2 files changed, 58 insertions(+), 41 deletions(-)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 58d406230d89..cad18f3660ae 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -458,10 +458,10 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
 		dma_cookie_complete(txd);
 
 	/* If the transfer was a memset, free our temporary buffer */
-	if (desc->memset) {
+	if (desc->memset_buffer) {
 		dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
 			      desc->memset_paddr);
-		desc->memset = false;
+		desc->memset_buffer = false;
 	}
 
 	/* move children to free_list */
@@ -881,6 +881,46 @@ err_desc_get:
 	return NULL;
 }
 
+static struct at_desc *atc_create_memset_desc(struct dma_chan *chan,
+					      dma_addr_t psrc,
+					      dma_addr_t pdst,
+					      size_t len)
+{
+	struct at_dma_chan *atchan = to_at_dma_chan(chan);
+	struct at_desc *desc;
+	size_t xfer_count;
+
+	u32 ctrla = ATC_SRC_WIDTH(2) | ATC_DST_WIDTH(2);
+	u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
+		ATC_SRC_ADDR_MODE_FIXED |
+		ATC_DST_ADDR_MODE_INCR |
+		ATC_FC_MEM2MEM;
+
+	xfer_count = len >> 2;
+	if (xfer_count > ATC_BTSIZE_MAX) {
+		dev_err(chan2dev(chan), "%s: buffer is too big\n",
+			__func__);
+		return NULL;
+	}
+
+	desc = atc_desc_get(atchan);
+	if (!desc) {
+		dev_err(chan2dev(chan), "%s: can't get a descriptor\n",
+			__func__);
+		return NULL;
+	}
+
+	desc->lli.saddr = psrc;
+	desc->lli.daddr = pdst;
+	desc->lli.ctrla = ctrla | xfer_count;
+	desc->lli.ctrlb = ctrlb;
+
+	desc->txd.cookie = 0;
+	desc->len = len;
+
+	return desc;
+}
+
 /**
  * atc_prep_dma_memset - prepare a memcpy operation
  * @chan: the channel to prepare operation on
@@ -893,12 +933,10 @@ static struct dma_async_tx_descriptor *
 atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
 		    size_t len, unsigned long flags)
 {
-	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
 	struct at_dma		*atdma = to_at_dma(chan->device);
-	struct at_desc		*desc = NULL;
-	size_t			xfer_count;
-	u32			ctrla;
-	u32			ctrlb;
+	struct at_desc		*desc;
+	void __iomem		*vaddr;
+	dma_addr_t		paddr;
 
 	dev_vdbg(chan2dev(chan), "%s: d0x%x v0x%x l0x%zx f0x%lx\n", __func__,
 		dest, value, len, flags);
@@ -914,46 +952,26 @@ atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
 		return NULL;
 	}
 
-	xfer_count = len >> 2;
-	if (xfer_count > ATC_BTSIZE_MAX) {
-		dev_err(chan2dev(chan), "%s: buffer is too big\n",
+	vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr);
+	if (!vaddr) {
+		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
 			__func__);
 		return NULL;
 	}
+	*(u32*)vaddr = value;
 
-	ctrlb =   ATC_DEFAULT_CTRLB | ATC_IEN
-		| ATC_SRC_ADDR_MODE_FIXED
-		| ATC_DST_ADDR_MODE_INCR
-		| ATC_FC_MEM2MEM;
-
-	ctrla = ATC_SRC_WIDTH(2) |
-		ATC_DST_WIDTH(2);
-
-	desc = atc_desc_get(atchan);
+	desc = atc_create_memset_desc(chan, paddr, dest, len);
 	if (!desc) {
-		dev_err(chan2dev(chan), "%s: can't get a descriptor\n",
+		dev_err(chan2dev(chan), "%s: couldn't get a descriptor\n",
 			__func__);
-		return NULL;
+		goto err_free_buffer;
 	}
 
-	desc->memset_vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC,
-					    &desc->memset_paddr);
-	if (!desc->memset_vaddr) {
-		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
-			__func__);
-		goto err_put_desc;
-	}
-
-	*desc->memset_vaddr = value;
-	desc->memset = true;
-
-	desc->lli.saddr = desc->memset_paddr;
-	desc->lli.daddr = dest;
-	desc->lli.ctrla = ctrla | xfer_count;
-	desc->lli.ctrlb = ctrlb;
+	desc->memset_paddr = paddr;
+	desc->memset_vaddr = vaddr;
+	desc->memset_buffer = true;
 
 	desc->txd.cookie = -EBUSY;
-	desc->len = len;
 	desc->total_len = len;
 
 	/* set end-of-link on the descriptor */
@@ -963,12 +981,11 @@ atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
 
 	return &desc->txd;
 
-err_put_desc:
-	atc_desc_put(atchan, desc);
+err_free_buffer:
+	dma_pool_free(atdma->memset_pool, vaddr, paddr);
 	return NULL;
 }
 
-
 /**
  * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
  * @chan: DMA channel
diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h
index c3bebbe899ac..d1cfc8c876f9 100644
--- a/drivers/dma/at_hdmac_regs.h
+++ b/drivers/dma/at_hdmac_regs.h
@@ -202,7 +202,7 @@ struct at_desc {
 	size_t				src_hole;
 
 	/* Memset temporary buffer */
-	bool				memset;
+	bool				memset_buffer;
 	dma_addr_t			memset_paddr;
 	int				*memset_vaddr;
 };
-- 
2.6.2

[PATCH v2 1/2] dmaengine: hdmac: factorise memset descriptor allocation

[Nicolas Ferre]

Le 22/10/2015 11:40, Maxime Ripard a ?crit :
> The memset and scatter gathered memset are going to use some common logic
> to create their descriptors.
> 
> Move that logic into a function of its own so that we can share it with the
> future memset_sg callback.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/dma/at_hdmac.c      | 97 ++++++++++++++++++++++++++-------------------
>  drivers/dma/at_hdmac_regs.h |  2 +-
>  2 files changed, 58 insertions(+), 41 deletions(-)
> 
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index 58d406230d89..cad18f3660ae 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -458,10 +458,10 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
>  		dma_cookie_complete(txd);
>  
>  	/* If the transfer was a memset, free our temporary buffer */
> -	if (desc->memset) {
> +	if (desc->memset_buffer) {
>  		dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
>  			      desc->memset_paddr);
> -		desc->memset = false;
> +		desc->memset_buffer = false;
>  	}
>  
>  	/* move children to free_list */
> @@ -881,6 +881,46 @@ err_desc_get:
>  	return NULL;
>  }
>  
> +static struct at_desc *atc_create_memset_desc(struct dma_chan *chan,
> +					      dma_addr_t psrc,
> +					      dma_addr_t pdst,
> +					      size_t len)
> +{
> +	struct at_dma_chan *atchan = to_at_dma_chan(chan);
> +	struct at_desc *desc;
> +	size_t xfer_count;
> +
> +	u32 ctrla = ATC_SRC_WIDTH(2) | ATC_DST_WIDTH(2);
> +	u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
> +		ATC_SRC_ADDR_MODE_FIXED |
> +		ATC_DST_ADDR_MODE_INCR |
> +		ATC_FC_MEM2MEM;
> +
> +	xfer_count = len >> 2;
> +	if (xfer_count > ATC_BTSIZE_MAX) {
> +		dev_err(chan2dev(chan), "%s: buffer is too big\n",
> +			__func__);
> +		return NULL;
> +	}
> +
> +	desc = atc_desc_get(atchan);
> +	if (!desc) {
> +		dev_err(chan2dev(chan), "%s: can't get a descriptor\n",
> +			__func__);
> +		return NULL;
> +	}
> +
> +	desc->lli.saddr = psrc;
> +	desc->lli.daddr = pdst;
> +	desc->lli.ctrla = ctrla | xfer_count;
> +	desc->lli.ctrlb = ctrlb;
> +
> +	desc->txd.cookie = 0;
> +	desc->len = len;
> +
> +	return desc;
> +}
> +
>  /**
>   * atc_prep_dma_memset - prepare a memcpy operation
>   * @chan: the channel to prepare operation on
> @@ -893,12 +933,10 @@ static struct dma_async_tx_descriptor *
>  atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
>  		    size_t len, unsigned long flags)
>  {
> -	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
>  	struct at_dma		*atdma = to_at_dma(chan->device);
> -	struct at_desc		*desc = NULL;
> -	size_t			xfer_count;
> -	u32			ctrla;
> -	u32			ctrlb;
> +	struct at_desc		*desc;
> +	void __iomem		*vaddr;
> +	dma_addr_t		paddr;
>  
>  	dev_vdbg(chan2dev(chan), "%s: d0x%x v0x%x l0x%zx f0x%lx\n", __func__,
>  		dest, value, len, flags);
> @@ -914,46 +952,26 @@ atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
>  		return NULL;
>  	}
>  
> -	xfer_count = len >> 2;
> -	if (xfer_count > ATC_BTSIZE_MAX) {
> -		dev_err(chan2dev(chan), "%s: buffer is too big\n",
> +	vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr);
> +	if (!vaddr) {
> +		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
>  			__func__);
>  		return NULL;
>  	}
> +	*(u32*)vaddr = value;
>  
> -	ctrlb =   ATC_DEFAULT_CTRLB | ATC_IEN
> -		| ATC_SRC_ADDR_MODE_FIXED
> -		| ATC_DST_ADDR_MODE_INCR
> -		| ATC_FC_MEM2MEM;
> -
> -	ctrla = ATC_SRC_WIDTH(2) |
> -		ATC_DST_WIDTH(2);
> -
> -	desc = atc_desc_get(atchan);
> +	desc = atc_create_memset_desc(chan, paddr, dest, len);
>  	if (!desc) {
> -		dev_err(chan2dev(chan), "%s: can't get a descriptor\n",
> +		dev_err(chan2dev(chan), "%s: couldn't get a descriptor\n",
>  			__func__);

Nitpicking: as you already have a dev_err() for each error possible in
the called function, you wouldn't need more log hereunder...

otherwise, I'm okay:
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>


> -		return NULL;
> +		goto err_free_buffer;
>  	}
>  
> -	desc->memset_vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC,
> -					    &desc->memset_paddr);
> -	if (!desc->memset_vaddr) {
> -		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
> -			__func__);
> -		goto err_put_desc;
> -	}
> -
> -	*desc->memset_vaddr = value;
> -	desc->memset = true;
> -
> -	desc->lli.saddr = desc->memset_paddr;
> -	desc->lli.daddr = dest;
> -	desc->lli.ctrla = ctrla | xfer_count;
> -	desc->lli.ctrlb = ctrlb;
> +	desc->memset_paddr = paddr;
> +	desc->memset_vaddr = vaddr;
> +	desc->memset_buffer = true;
>  
>  	desc->txd.cookie = -EBUSY;
> -	desc->len = len;
>  	desc->total_len = len;
>  
>  	/* set end-of-link on the descriptor */
> @@ -963,12 +981,11 @@ atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
>  
>  	return &desc->txd;
>  
> -err_put_desc:
> -	atc_desc_put(atchan, desc);
> +err_free_buffer:
> +	dma_pool_free(atdma->memset_pool, vaddr, paddr);
>  	return NULL;
>  }
>  
> -
>  /**
>   * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
>   * @chan: DMA channel
> diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h
> index c3bebbe899ac..d1cfc8c876f9 100644
> --- a/drivers/dma/at_hdmac_regs.h
> +++ b/drivers/dma/at_hdmac_regs.h
> @@ -202,7 +202,7 @@ struct at_desc {
>  	size_t				src_hole;
>  
>  	/* Memset temporary buffer */
> -	bool				memset;
> +	bool				memset_buffer;
>  	dma_addr_t			memset_paddr;
>  	int				*memset_vaddr;
>  };
> 


-- 
Nicolas Ferre

Re: [PATCH v2 1/2] dmaengine: hdmac: factorise memset descriptor allocation

[Nicolas Ferre]

Le 22/10/2015 11:40, Maxime Ripard a écrit :
> The memset and scatter gathered memset are going to use some common logic
> to create their descriptors.
> 
> Move that logic into a function of its own so that we can share it with the
> future memset_sg callback.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
> ---
>  drivers/dma/at_hdmac.c      | 97 ++++++++++++++++++++++++++-------------------
>  drivers/dma/at_hdmac_regs.h |  2 +-
>  2 files changed, 58 insertions(+), 41 deletions(-)
> 
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index 58d406230d89..cad18f3660ae 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -458,10 +458,10 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
>  		dma_cookie_complete(txd);
>  
>  	/* If the transfer was a memset, free our temporary buffer */
> -	if (desc->memset) {
> +	if (desc->memset_buffer) {
>  		dma_pool_free(atdma->memset_pool, desc->memset_vaddr,
>  			      desc->memset_paddr);
> -		desc->memset = false;
> +		desc->memset_buffer = false;
>  	}
>  
>  	/* move children to free_list */
> @@ -881,6 +881,46 @@ err_desc_get:
>  	return NULL;
>  }
>  
> +static struct at_desc *atc_create_memset_desc(struct dma_chan *chan,
> +					      dma_addr_t psrc,
> +					      dma_addr_t pdst,
> +					      size_t len)
> +{
> +	struct at_dma_chan *atchan = to_at_dma_chan(chan);
> +	struct at_desc *desc;
> +	size_t xfer_count;
> +
> +	u32 ctrla = ATC_SRC_WIDTH(2) | ATC_DST_WIDTH(2);
> +	u32 ctrlb = ATC_DEFAULT_CTRLB | ATC_IEN |
> +		ATC_SRC_ADDR_MODE_FIXED |
> +		ATC_DST_ADDR_MODE_INCR |
> +		ATC_FC_MEM2MEM;
> +
> +	xfer_count = len >> 2;
> +	if (xfer_count > ATC_BTSIZE_MAX) {
> +		dev_err(chan2dev(chan), "%s: buffer is too big\n",
> +			__func__);
> +		return NULL;
> +	}
> +
> +	desc = atc_desc_get(atchan);
> +	if (!desc) {
> +		dev_err(chan2dev(chan), "%s: can't get a descriptor\n",
> +			__func__);
> +		return NULL;
> +	}
> +
> +	desc->lli.saddr = psrc;
> +	desc->lli.daddr = pdst;
> +	desc->lli.ctrla = ctrla | xfer_count;
> +	desc->lli.ctrlb = ctrlb;
> +
> +	desc->txd.cookie = 0;
> +	desc->len = len;
> +
> +	return desc;
> +}
> +
>  /**
>   * atc_prep_dma_memset - prepare a memcpy operation
>   * @chan: the channel to prepare operation on
> @@ -893,12 +933,10 @@ static struct dma_async_tx_descriptor *
>  atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
>  		    size_t len, unsigned long flags)
>  {
> -	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
>  	struct at_dma		*atdma = to_at_dma(chan->device);
> -	struct at_desc		*desc = NULL;
> -	size_t			xfer_count;
> -	u32			ctrla;
> -	u32			ctrlb;
> +	struct at_desc		*desc;
> +	void __iomem		*vaddr;
> +	dma_addr_t		paddr;
>  
>  	dev_vdbg(chan2dev(chan), "%s: d0x%x v0x%x l0x%zx f0x%lx\n", __func__,
>  		dest, value, len, flags);
> @@ -914,46 +952,26 @@ atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
>  		return NULL;
>  	}
>  
> -	xfer_count = len >> 2;
> -	if (xfer_count > ATC_BTSIZE_MAX) {
> -		dev_err(chan2dev(chan), "%s: buffer is too big\n",
> +	vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr);
> +	if (!vaddr) {
> +		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
>  			__func__);
>  		return NULL;
>  	}
> +	*(u32*)vaddr = value;
>  
> -	ctrlb =   ATC_DEFAULT_CTRLB | ATC_IEN
> -		| ATC_SRC_ADDR_MODE_FIXED
> -		| ATC_DST_ADDR_MODE_INCR
> -		| ATC_FC_MEM2MEM;
> -
> -	ctrla = ATC_SRC_WIDTH(2) |
> -		ATC_DST_WIDTH(2);
> -
> -	desc = atc_desc_get(atchan);
> +	desc = atc_create_memset_desc(chan, paddr, dest, len);
>  	if (!desc) {
> -		dev_err(chan2dev(chan), "%s: can't get a descriptor\n",
> +		dev_err(chan2dev(chan), "%s: couldn't get a descriptor\n",
>  			__func__);

Nitpicking: as you already have a dev_err() for each error possible in
the called function, you wouldn't need more log hereunder...

otherwise, I'm okay:
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>


> -		return NULL;
> +		goto err_free_buffer;
>  	}
>  
> -	desc->memset_vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC,
> -					    &desc->memset_paddr);
> -	if (!desc->memset_vaddr) {
> -		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
> -			__func__);
> -		goto err_put_desc;
> -	}
> -
> -	*desc->memset_vaddr = value;
> -	desc->memset = true;
> -
> -	desc->lli.saddr = desc->memset_paddr;
> -	desc->lli.daddr = dest;
> -	desc->lli.ctrla = ctrla | xfer_count;
> -	desc->lli.ctrlb = ctrlb;
> +	desc->memset_paddr = paddr;
> +	desc->memset_vaddr = vaddr;
> +	desc->memset_buffer = true;
>  
>  	desc->txd.cookie = -EBUSY;
> -	desc->len = len;
>  	desc->total_len = len;
>  
>  	/* set end-of-link on the descriptor */
> @@ -963,12 +981,11 @@ atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
>  
>  	return &desc->txd;
>  
> -err_put_desc:
> -	atc_desc_put(atchan, desc);
> +err_free_buffer:
> +	dma_pool_free(atdma->memset_pool, vaddr, paddr);
>  	return NULL;
>  }
>  
> -
>  /**
>   * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
>   * @chan: DMA channel
> diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h
> index c3bebbe899ac..d1cfc8c876f9 100644
> --- a/drivers/dma/at_hdmac_regs.h
> +++ b/drivers/dma/at_hdmac_regs.h
> @@ -202,7 +202,7 @@ struct at_desc {
>  	size_t				src_hole;
>  
>  	/* Memset temporary buffer */
> -	bool				memset;
> +	bool				memset_buffer;
>  	dma_addr_t			memset_paddr;
>  	int				*memset_vaddr;
>  };
> 


-- 
Nicolas Ferre

[PATCH v2 2/2] dmaengine: hdmac: Add scatter-gathered memset support

[Maxime Ripard]

Just like memset support, the HDMAC might be used to do a memset over a
discontiguous memory area.

In such a case, we'll just build up a chain of memset descriptors over the
contiguous chunks of memory to set, in order to allow such a support.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/dma/at_hdmac.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index cad18f3660ae..4e55239c7a30 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -986,6 +986,83 @@ err_free_buffer:
 	return NULL;
 }
 
+static struct dma_async_tx_descriptor *
+atc_prep_dma_memset_sg(struct dma_chan *chan,
+		       struct scatterlist *sgl,
+		       unsigned int sg_len, int value,
+		       unsigned long flags)
+{
+	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
+	struct at_dma		*atdma = to_at_dma(chan->device);
+	struct at_desc		*desc = NULL, *first = NULL, *prev = NULL;
+	struct scatterlist	*sg;
+	void __iomem		*vaddr;
+	dma_addr_t		paddr;
+	size_t			total_len = 0;
+	int			i;
+
+	dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__,
+		 value, sg_len, flags);
+
+	if (unlikely(!sgl || !sg_len)) {
+		dev_dbg(chan2dev(chan), "%s: scatterlist is empty!\n",
+			__func__);
+		return NULL;
+	}
+
+	vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr);
+	if (!vaddr) {
+		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
+			__func__);
+		return NULL;
+	}
+	*(u32*)vaddr = value;
+
+	for_each_sg(sgl, sg, sg_len, i) {
+		dma_addr_t dest = sg_dma_address(sg);
+		size_t len = sg_dma_len(sg);
+
+		dev_vdbg(chan2dev(chan), "%s: d0x%08x, l0x%zx\n",
+			 __func__, dest, len);
+
+		if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {
+			dev_err(chan2dev(chan), "%s: buffer is not aligned\n",
+				__func__);
+			goto err_put_desc;
+		}
+
+		desc = atc_create_memset_desc(chan, paddr, dest, len);
+		if (!desc)
+			goto err_put_desc;
+
+		atc_desc_chain(&first, &prev, desc);
+
+		total_len += len;
+	}
+
+	/*
+	 * Only set the buffer pointers on the last descriptor to
+	 * avoid free'ing while we have our transfer still going
+	 */
+	desc->memset_paddr = paddr;
+	desc->memset_vaddr = vaddr;
+	desc->memset_buffer = true;
+
+	first->txd.cookie = -EBUSY;
+	first->total_len = total_len;
+
+	/* set end-of-link on the descriptor */
+	set_desc_eol(desc);
+
+	first->txd.flags = flags;
+
+	return &first->txd;
+
+err_put_desc:
+	atc_desc_put(atchan, first);
+	return NULL;
+}
+
 /**
  * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
  * @chan: DMA channel
@@ -1868,6 +1945,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
 	dma_cap_set(DMA_INTERLEAVE, at91sam9g45_config.cap_mask);
 	dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask);
 	dma_cap_set(DMA_MEMSET, at91sam9g45_config.cap_mask);
+	dma_cap_set(DMA_MEMSET_SG, at91sam9g45_config.cap_mask);
 	dma_cap_set(DMA_PRIVATE, at91sam9g45_config.cap_mask);
 	dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask);
 	dma_cap_set(DMA_SG, at91sam9g45_config.cap_mask);
@@ -1989,6 +2067,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
 
 	if (dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask)) {
 		atdma->dma_common.device_prep_dma_memset = atc_prep_dma_memset;
+		atdma->dma_common.device_prep_dma_memset_sg = atc_prep_dma_memset_sg;
 		atdma->dma_common.fill_align = DMAENGINE_ALIGN_4_BYTES;
 	}
 
-- 
2.6.2

[PATCH v2 2/2] dmaengine: hdmac: Add scatter-gathered memset support

[Maxime Ripard]

Just like memset support, the HDMAC might be used to do a memset over a
discontiguous memory area.

In such a case, we'll just build up a chain of memset descriptors over the
contiguous chunks of memory to set, in order to allow such a support.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
---
 drivers/dma/at_hdmac.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 79 insertions(+)

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index cad18f3660ae..4e55239c7a30 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -986,6 +986,83 @@ err_free_buffer:
 	return NULL;
 }
 
+static struct dma_async_tx_descriptor *
+atc_prep_dma_memset_sg(struct dma_chan *chan,
+		       struct scatterlist *sgl,
+		       unsigned int sg_len, int value,
+		       unsigned long flags)
+{
+	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
+	struct at_dma		*atdma = to_at_dma(chan->device);
+	struct at_desc		*desc = NULL, *first = NULL, *prev = NULL;
+	struct scatterlist	*sg;
+	void __iomem		*vaddr;
+	dma_addr_t		paddr;
+	size_t			total_len = 0;
+	int			i;
+
+	dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__,
+		 value, sg_len, flags);
+
+	if (unlikely(!sgl || !sg_len)) {
+		dev_dbg(chan2dev(chan), "%s: scatterlist is empty!\n",
+			__func__);
+		return NULL;
+	}
+
+	vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr);
+	if (!vaddr) {
+		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
+			__func__);
+		return NULL;
+	}
+	*(u32*)vaddr = value;
+
+	for_each_sg(sgl, sg, sg_len, i) {
+		dma_addr_t dest = sg_dma_address(sg);
+		size_t len = sg_dma_len(sg);
+
+		dev_vdbg(chan2dev(chan), "%s: d0x%08x, l0x%zx\n",
+			 __func__, dest, len);
+
+		if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {
+			dev_err(chan2dev(chan), "%s: buffer is not aligned\n",
+				__func__);
+			goto err_put_desc;
+		}
+
+		desc = atc_create_memset_desc(chan, paddr, dest, len);
+		if (!desc)
+			goto err_put_desc;
+
+		atc_desc_chain(&first, &prev, desc);
+
+		total_len += len;
+	}
+
+	/*
+	 * Only set the buffer pointers on the last descriptor to
+	 * avoid free'ing while we have our transfer still going
+	 */
+	desc->memset_paddr = paddr;
+	desc->memset_vaddr = vaddr;
+	desc->memset_buffer = true;
+
+	first->txd.cookie = -EBUSY;
+	first->total_len = total_len;
+
+	/* set end-of-link on the descriptor */
+	set_desc_eol(desc);
+
+	first->txd.flags = flags;
+
+	return &first->txd;
+
+err_put_desc:
+	atc_desc_put(atchan, first);
+	return NULL;
+}
+
 /**
  * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
  * @chan: DMA channel
@@ -1868,6 +1945,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
 	dma_cap_set(DMA_INTERLEAVE, at91sam9g45_config.cap_mask);
 	dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask);
 	dma_cap_set(DMA_MEMSET, at91sam9g45_config.cap_mask);
+	dma_cap_set(DMA_MEMSET_SG, at91sam9g45_config.cap_mask);
 	dma_cap_set(DMA_PRIVATE, at91sam9g45_config.cap_mask);
 	dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask);
 	dma_cap_set(DMA_SG, at91sam9g45_config.cap_mask);
@@ -1989,6 +2067,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
 
 	if (dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask)) {
 		atdma->dma_common.device_prep_dma_memset = atc_prep_dma_memset;
+		atdma->dma_common.device_prep_dma_memset_sg = atc_prep_dma_memset_sg;
 		atdma->dma_common.fill_align = DMAENGINE_ALIGN_4_BYTES;
 	}
 
-- 
2.6.2

[PATCH v2 2/2] dmaengine: hdmac: Add scatter-gathered memset support

[Nicolas Ferre]

Le 22/10/2015 11:41, Maxime Ripard a ?crit :
> Just like memset support, the HDMAC might be used to do a memset over a
> discontiguous memory area.
> 
> In such a case, we'll just build up a chain of memset descriptors over the
> contiguous chunks of memory to set, in order to allow such a support.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Yep, seems good!
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

Thanks Maxime, bye.


> ---
>  drivers/dma/at_hdmac.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 79 insertions(+)
> 
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index cad18f3660ae..4e55239c7a30 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -986,6 +986,83 @@ err_free_buffer:
>  	return NULL;
>  }
>  
> +static struct dma_async_tx_descriptor *
> +atc_prep_dma_memset_sg(struct dma_chan *chan,
> +		       struct scatterlist *sgl,
> +		       unsigned int sg_len, int value,
> +		       unsigned long flags)
> +{
> +	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
> +	struct at_dma		*atdma = to_at_dma(chan->device);
> +	struct at_desc		*desc = NULL, *first = NULL, *prev = NULL;
> +	struct scatterlist	*sg;
> +	void __iomem		*vaddr;
> +	dma_addr_t		paddr;
> +	size_t			total_len = 0;
> +	int			i;
> +
> +	dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__,
> +		 value, sg_len, flags);
> +
> +	if (unlikely(!sgl || !sg_len)) {
> +		dev_dbg(chan2dev(chan), "%s: scatterlist is empty!\n",
> +			__func__);
> +		return NULL;
> +	}
> +
> +	vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr);
> +	if (!vaddr) {
> +		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
> +			__func__);
> +		return NULL;
> +	}
> +	*(u32*)vaddr = value;
> +
> +	for_each_sg(sgl, sg, sg_len, i) {
> +		dma_addr_t dest = sg_dma_address(sg);
> +		size_t len = sg_dma_len(sg);
> +
> +		dev_vdbg(chan2dev(chan), "%s: d0x%08x, l0x%zx\n",
> +			 __func__, dest, len);
> +
> +		if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {
> +			dev_err(chan2dev(chan), "%s: buffer is not aligned\n",
> +				__func__);
> +			goto err_put_desc;
> +		}
> +
> +		desc = atc_create_memset_desc(chan, paddr, dest, len);
> +		if (!desc)
> +			goto err_put_desc;
> +
> +		atc_desc_chain(&first, &prev, desc);
> +
> +		total_len += len;
> +	}
> +
> +	/*
> +	 * Only set the buffer pointers on the last descriptor to
> +	 * avoid free'ing while we have our transfer still going
> +	 */
> +	desc->memset_paddr = paddr;
> +	desc->memset_vaddr = vaddr;
> +	desc->memset_buffer = true;
> +
> +	first->txd.cookie = -EBUSY;
> +	first->total_len = total_len;
> +
> +	/* set end-of-link on the descriptor */
> +	set_desc_eol(desc);
> +
> +	first->txd.flags = flags;
> +
> +	return &first->txd;
> +
> +err_put_desc:
> +	atc_desc_put(atchan, first);
> +	return NULL;
> +}
> +
>  /**
>   * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
>   * @chan: DMA channel
> @@ -1868,6 +1945,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
>  	dma_cap_set(DMA_INTERLEAVE, at91sam9g45_config.cap_mask);
>  	dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask);
>  	dma_cap_set(DMA_MEMSET, at91sam9g45_config.cap_mask);
> +	dma_cap_set(DMA_MEMSET_SG, at91sam9g45_config.cap_mask);
>  	dma_cap_set(DMA_PRIVATE, at91sam9g45_config.cap_mask);
>  	dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask);
>  	dma_cap_set(DMA_SG, at91sam9g45_config.cap_mask);
> @@ -1989,6 +2067,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
>  
>  	if (dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask)) {
>  		atdma->dma_common.device_prep_dma_memset = atc_prep_dma_memset;
> +		atdma->dma_common.device_prep_dma_memset_sg = atc_prep_dma_memset_sg;
>  		atdma->dma_common.fill_align = DMAENGINE_ALIGN_4_BYTES;
>  	}
>  
> 


-- 
Nicolas Ferre

Re: [PATCH v2 2/2] dmaengine: hdmac: Add scatter-gathered memset support

[Nicolas Ferre]

Le 22/10/2015 11:41, Maxime Ripard a écrit :
> Just like memset support, the HDMAC might be used to do a memset over a
> discontiguous memory area.
> 
> In such a case, we'll just build up a chain of memset descriptors over the
> contiguous chunks of memory to set, in order to allow such a support.
> 
> Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

Yep, seems good!
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>

Thanks Maxime, bye.


> ---
>  drivers/dma/at_hdmac.c | 79 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 79 insertions(+)
> 
> diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
> index cad18f3660ae..4e55239c7a30 100644
> --- a/drivers/dma/at_hdmac.c
> +++ b/drivers/dma/at_hdmac.c
> @@ -986,6 +986,83 @@ err_free_buffer:
>  	return NULL;
>  }
>  
> +static struct dma_async_tx_descriptor *
> +atc_prep_dma_memset_sg(struct dma_chan *chan,
> +		       struct scatterlist *sgl,
> +		       unsigned int sg_len, int value,
> +		       unsigned long flags)
> +{
> +	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
> +	struct at_dma		*atdma = to_at_dma(chan->device);
> +	struct at_desc		*desc = NULL, *first = NULL, *prev = NULL;
> +	struct scatterlist	*sg;
> +	void __iomem		*vaddr;
> +	dma_addr_t		paddr;
> +	size_t			total_len = 0;
> +	int			i;
> +
> +	dev_vdbg(chan2dev(chan), "%s: v0x%x l0x%zx f0x%lx\n", __func__,
> +		 value, sg_len, flags);
> +
> +	if (unlikely(!sgl || !sg_len)) {
> +		dev_dbg(chan2dev(chan), "%s: scatterlist is empty!\n",
> +			__func__);
> +		return NULL;
> +	}
> +
> +	vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr);
> +	if (!vaddr) {
> +		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
> +			__func__);
> +		return NULL;
> +	}
> +	*(u32*)vaddr = value;
> +
> +	for_each_sg(sgl, sg, sg_len, i) {
> +		dma_addr_t dest = sg_dma_address(sg);
> +		size_t len = sg_dma_len(sg);
> +
> +		dev_vdbg(chan2dev(chan), "%s: d0x%08x, l0x%zx\n",
> +			 __func__, dest, len);
> +
> +		if (!is_dma_fill_aligned(chan->device, dest, 0, len)) {
> +			dev_err(chan2dev(chan), "%s: buffer is not aligned\n",
> +				__func__);
> +			goto err_put_desc;
> +		}
> +
> +		desc = atc_create_memset_desc(chan, paddr, dest, len);
> +		if (!desc)
> +			goto err_put_desc;
> +
> +		atc_desc_chain(&first, &prev, desc);
> +
> +		total_len += len;
> +	}
> +
> +	/*
> +	 * Only set the buffer pointers on the last descriptor to
> +	 * avoid free'ing while we have our transfer still going
> +	 */
> +	desc->memset_paddr = paddr;
> +	desc->memset_vaddr = vaddr;
> +	desc->memset_buffer = true;
> +
> +	first->txd.cookie = -EBUSY;
> +	first->total_len = total_len;
> +
> +	/* set end-of-link on the descriptor */
> +	set_desc_eol(desc);
> +
> +	first->txd.flags = flags;
> +
> +	return &first->txd;
> +
> +err_put_desc:
> +	atc_desc_put(atchan, first);
> +	return NULL;
> +}
> +
>  /**
>   * atc_prep_slave_sg - prepare descriptors for a DMA_SLAVE transaction
>   * @chan: DMA channel
> @@ -1868,6 +1945,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
>  	dma_cap_set(DMA_INTERLEAVE, at91sam9g45_config.cap_mask);
>  	dma_cap_set(DMA_MEMCPY, at91sam9g45_config.cap_mask);
>  	dma_cap_set(DMA_MEMSET, at91sam9g45_config.cap_mask);
> +	dma_cap_set(DMA_MEMSET_SG, at91sam9g45_config.cap_mask);
>  	dma_cap_set(DMA_PRIVATE, at91sam9g45_config.cap_mask);
>  	dma_cap_set(DMA_SLAVE, at91sam9g45_config.cap_mask);
>  	dma_cap_set(DMA_SG, at91sam9g45_config.cap_mask);
> @@ -1989,6 +2067,7 @@ static int __init at_dma_probe(struct platform_device *pdev)
>  
>  	if (dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask)) {
>  		atdma->dma_common.device_prep_dma_memset = atc_prep_dma_memset;
> +		atdma->dma_common.device_prep_dma_memset_sg = atc_prep_dma_memset_sg;
>  		atdma->dma_common.fill_align = DMAENGINE_ALIGN_4_BYTES;
>  	}
>  
> 


-- 
Nicolas Ferre

[PATCH v2 0/2] dmaengine: hdmac: Add scatter-gathered memset support

[Vinod Koul]

On Thu, Oct 22, 2015 at 11:40:58AM +0200, Maxime Ripard wrote:
> Hi Vinod,
> 
> Here is a patch serie that adds support in the Atmel HDMAC for memset
> over a discontiguous memory area.
> 
> Just like for the memset, it's used on those SoCs to support
> framebuffer related operations that cannot be performed either by the
> display engine or the (non-existent) GPU.

Applied, thanks

-- 
~Vinod

Re: [PATCH v2 0/2] dmaengine: hdmac: Add scatter-gathered memset support

[Vinod Koul]

On Thu, Oct 22, 2015 at 11:40:58AM +0200, Maxime Ripard wrote:
> Hi Vinod,
> 
> Here is a patch serie that adds support in the Atmel HDMAC for memset
> over a discontiguous memory area.
> 
> Just like for the memset, it's used on those SoCs to support
> framebuffer related operations that cannot be performed either by the
> display engine or the (non-existent) GPU.

Applied, thanks

-- 
~Vinod