[PATCH v3 0/9] dmaengine: Add new API to combine configuration and descriptor preparation

[PATCH v3 0/9] dmaengine: Add new API to combine configuration and descriptor preparation

[Frank Li]

Previously, configuration and preparation required two separate calls. This
works well when configuration is done only once during initialization.

However, in cases where the burst length or source/destination address must
be adjusted for each transfer, calling two functions is verbose.

	if (dmaengine_slave_config(chan, &sconf)) {
		dev_err(dev, "DMA slave config fail\n");
		return -EIO;
	}

	tx = dmaengine_prep_slave_single(chan, dma_local, len, dir, flags);

After new API added

	tx = dmaengine_prep_config_single(chan, dma_local, len, dir, flags, &sconf);

Additional, prevous two calls requires additional locking to ensure both
steps complete atomically.

    mutex_lock()
    dmaengine_slave_config()
    dmaengine_prep_slave_single()
    mutex_unlock()

after new API added, mutex lock can be moved. See patch
     nvmet: pci-epf: Use dmaengine_prep_config_single_safe() API

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
Changes in v3:
- collect review tags
- create safe version in framework
- Link to v2: https://lore.kernel.org/r/20251218-dma_prep_config-v2-0-c07079836128@nxp.com

Changes in v2:
- Use name dmaengine_prep_config_single() and dmaengine_prep_config_sg()
- Add _safe version to avoid confuse, which needn't additional mutex.
- Update document/
- Update commit message. add () for function name. Use upcase for subject.
- Add more explain for remove lock.
- Link to v1: https://lore.kernel.org/r/20251208-dma_prep_config-v1-0-53490c5e1e2a@nxp.com

---
Frank Li (9):
      dmaengine: Add API to combine configuration and preparation (sg and single)
      dmaengine: Add safe API to combine configuration and preparation
      PCI: endpoint: pci-epf-test: Use dmaenigne_prep_config_single() to simplify code
      dmaengine: dw-edma: Use new .device_prep_config_sg() callback
      dmaengine: dw-edma: Pass dma_slave_config to dw_edma_device_transfer()
      nvmet: pci-epf: Remove unnecessary dmaengine_terminate_sync() on each DMA transfer
      nvmet: pci-epf: Use dmaengine_prep_config_single_safe() API
      PCI: epf-mhi: Use dmaengine_prep_config_single() to simplify code
      crypto: atmel: Use dmaengine_prep_config_single() API

 Documentation/driver-api/dmaengine/client.rst |   9 ++
 drivers/crypto/atmel-aes.c                    |  10 +--
 drivers/dma/dmaengine.c                       |   3 +
 drivers/dma/dw-edma/dw-edma-core.c            |  41 ++++++---
 drivers/nvme/target/pci-epf.c                 |  21 ++---
 drivers/pci/endpoint/functions/pci-epf-mhi.c  |  52 ++++--------
 drivers/pci/endpoint/functions/pci-epf-test.c |   8 +-
 include/linux/dmaengine.h                     | 117 ++++++++++++++++++++++++--
 8 files changed, 177 insertions(+), 84 deletions(-)
---
base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
change-id: 20251204-dma_prep_config-654170d245a2

Best regards,
--
Frank Li <Frank.Li@nxp.com>

[PATCH v3 1/9] dmaengine: Add API to combine configuration and preparation (sg and single)

[Frank Li]

Previously, configuration and preparation required two separate calls. This
works well when configuration is done only once during initialization.

However, in cases where the burst length or source/destination address must
be adjusted for each transfer, calling two functions is verbose and
requires additional locking to ensure both steps complete atomically.

Add a new API dmaengine_prep_config_single() and dmaengine_prep_config_sg()
and callback device_prep_config_sg() that combines configuration and
preparation into a single operation. If the configuration argument is
passed as NULL, fall back to the existing implementation.

Tested-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change in v3
- remove Deprecated for callback device_prep_slave_sg().
- Move condition check before sg init.
- split function at return type.
- move safe version to next patch

change in v2
- add () for function
- use short name device_prep_sg(), remove "slave" and "config". the 'slave'
is reduntant. after remove slave, the function name is difference existed
one, so remove _config suffix.
---
 Documentation/driver-api/dmaengine/client.rst |  9 ++++
 include/linux/dmaengine.h                     | 64 +++++++++++++++++++++++----
 2 files changed, 65 insertions(+), 8 deletions(-)

diff --git a/Documentation/driver-api/dmaengine/client.rst b/Documentation/driver-api/dmaengine/client.rst
index d491e385d61a98b8a804cd823caf254a2dc62cf4..5ee5d4a3596dd986b02f1bce3078ca6c4c1fb45a 100644
--- a/Documentation/driver-api/dmaengine/client.rst
+++ b/Documentation/driver-api/dmaengine/client.rst
@@ -80,6 +80,10 @@ The details of these operations are:
 
   - slave_sg: DMA a list of scatter gather buffers from/to a peripheral
 
+  - config_sg: Similar with slave_sg, just pass down dma_slave_config
+    struct to avoid calling dmaengine_slave_config() every time adjusting the
+    burst length or the FIFO address is needed.
+
   - peripheral_dma_vec: DMA an array of scatter gather buffers from/to a
     peripheral. Similar to slave_sg, but uses an array of dma_vec
     structures instead of a scatterlist.
@@ -106,6 +110,11 @@ The details of these operations are:
 		unsigned int sg_len, enum dma_data_direction direction,
 		unsigned long flags);
 
+     struct dma_async_tx_descriptor *dmaengine_prep_config_sg(
+		struct dma_chan *chan, struct scatterlist *sgl,
+		unsigned int sg_len, enum dma_transfer_direction dir,
+		unsigned long flags, struct dma_slave_config *config);
+
      struct dma_async_tx_descriptor *dmaengine_prep_peripheral_dma_vec(
 		struct dma_chan *chan, const struct dma_vec *vecs,
 		size_t nents, enum dma_data_direction direction,
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 99efe2b9b4ea9844ca6161208362ef18ef111d96..4994236aaadc45dbda260b63abe1fef47aa3d51e 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -835,6 +835,7 @@ struct dma_filter {
  *	where the address and size of each segment is located in one entry of
  *	the dma_vec array.
  * @device_prep_slave_sg: prepares a slave dma operation
+ * @device_prep_config_sg: prepares a slave DMA operation with dma_slave_config
  * @device_prep_dma_cyclic: prepare a cyclic dma operation suitable for audio.
  *	The function takes a buffer of size buf_len. The callback function will
  *	be called after period_len bytes have been transferred.
@@ -934,6 +935,11 @@ struct dma_device {
 		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 *(*device_prep_config_sg)(
+		struct dma_chan *chan, struct scatterlist *sgl,
+		unsigned int sg_len, enum dma_transfer_direction direction,
+		unsigned long flags, struct dma_slave_config *config,
+		void *context);
 	struct dma_async_tx_descriptor *(*device_prep_dma_cyclic)(
 		struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
 		size_t period_len, enum dma_transfer_direction direction,
@@ -974,22 +980,44 @@ static inline bool is_slave_direction(enum dma_transfer_direction direction)
 	       (direction == DMA_DEV_TO_DEV);
 }
 
-static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_single(
-	struct dma_chan *chan, dma_addr_t buf, size_t len,
-	enum dma_transfer_direction dir, unsigned long flags)
+static inline struct dma_async_tx_descriptor *
+dmaengine_prep_config_single(struct dma_chan *chan, dma_addr_t buf, size_t len,
+			     enum dma_transfer_direction dir,
+			     unsigned long flags,
+			     struct dma_slave_config *config)
 {
 	struct scatterlist sg;
+
+	if (!chan || !chan->device)
+		return NULL;
+
 	sg_init_table(&sg, 1);
 	sg_dma_address(&sg) = buf;
 	sg_dma_len(&sg) = len;
 
-	if (!chan || !chan->device || !chan->device->device_prep_slave_sg)
+	if (chan->device->device_prep_config_sg)
+		return chan->device->device_prep_config_sg(chan, &sg, 1, dir,
+							   flags, config, NULL);
+
+	if (config)
+		if (dmaengine_slave_config(chan, config))
+			return NULL;
+
+	if (!chan->device->device_prep_slave_sg)
 		return NULL;
 
 	return chan->device->device_prep_slave_sg(chan, &sg, 1,
 						  dir, flags, NULL);
 }
 
+static inline struct dma_async_tx_descriptor *
+dmaengine_prep_slave_single(struct dma_chan *chan, dma_addr_t buf, size_t len,
+			    enum dma_transfer_direction dir,
+			    unsigned long flags)
+{
+	return dmaengine_prep_config_single(chan, buf, len, dir, flags, NULL);
+}
+
 /**
  * dmaengine_prep_peripheral_dma_vec() - Prepare a DMA scatter-gather descriptor
  * @chan: The channel to be used for this descriptor
@@ -1009,17 +1037,37 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_peripheral_dma_vec(
 							    dir, flags);
 }
 
-static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_sg(
-	struct dma_chan *chan, struct scatterlist *sgl,	unsigned int sg_len,
-	enum dma_transfer_direction dir, unsigned long flags)
+static inline struct dma_async_tx_descriptor *
+dmaengine_prep_config_sg(struct dma_chan *chan, struct scatterlist *sgl,
+			 unsigned int sg_len, enum dma_transfer_direction dir,
+			 unsigned long flags, struct dma_slave_config *config)
 {
-	if (!chan || !chan->device || !chan->device->device_prep_slave_sg)
+	if (!chan || !chan->device)
+		return NULL;
+
+	if (chan->device->device_prep_config_sg)
+		return chan->device->device_prep_config_sg(chan, sgl, sg_len,
+				dir, flags, config, NULL);
+
+	if (config)
+		if (dmaengine_slave_config(chan, config))
+			return NULL;
+
+	if (!chan->device->device_prep_slave_sg)
 		return NULL;
 
 	return chan->device->device_prep_slave_sg(chan, sgl, sg_len,
 						  dir, flags, NULL);
 }
 
+static inline struct dma_async_tx_descriptor *
+dmaengine_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
+			unsigned int sg_len, enum dma_transfer_direction dir,
+			unsigned long flags)
+{
+	return dmaengine_prep_config_sg(chan, sgl, sg_len, dir, flags, NULL);
+}
+
 #ifdef CONFIG_RAPIDIO_DMA_ENGINE
 struct rio_dma_ext;
 static inline struct dma_async_tx_descriptor *dmaengine_prep_rio_sg(

-- 
2.34.1

[PATCH v3 2/9] dmaengine: Add safe API to combine configuration and preparation

[Frank Li]

Introduce dmaengine_prep_config_single_safe() and
dmaengine_prep_config_sg_safe() to provide a reentrant-safe way to
combine slave configuration and transfer preparation.

Drivers may implement the new device_prep_config_sg() callback to perform
both steps atomically. If the callback is not provided, the helpers fall
back to calling dmaengine_slave_config() followed by
dmaengine_prep_slave_sg() under per-channel mutex protection.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change in v3
- new patch
---
 drivers/dma/dmaengine.c   |  3 +++
 include/linux/dmaengine.h | 53 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index ca13cd39330ba4d822baaab412356a166b656350..53116300e61078ca89e78109bcf24a5f8c7e3369 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -1097,6 +1097,8 @@ static int __dma_async_device_channel_register(struct dma_device *device,
 	chan->dev->device.parent = device->dev;
 	chan->dev->chan = chan;
 	chan->dev->dev_id = device->dev_id;
+	mutex_init(&chan->lock);
+
 	if (!name)
 		dev_set_name(&chan->dev->device, "dma%dchan%d", device->dev_id, chan->chan_id);
 	else
@@ -1147,6 +1149,7 @@ static void __dma_async_device_channel_unregister(struct dma_device *device,
 	device->chancnt--;
 	chan->dev->chan = NULL;
 	mutex_unlock(&dma_list_mutex);
+	mutex_destroy(&chan->lock);
 	ida_free(&device->chan_ida, chan->chan_id);
 	device_unregister(&chan->dev->device);
 	free_percpu(chan->local);
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 4994236aaadc45dbda260b63abe1fef47aa3d51e..abb4a7424a0083c00730a945c1cb645f831fbd6f 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -322,6 +322,8 @@ struct dma_router {
  * @slave: ptr to the device using this channel
  * @cookie: last cookie value returned to client
  * @completed_cookie: last completed cookie for this channel
+ * @lock: protect between config and prepare transfer when driver have not
+ *	  implemented callback device_prep_config_sg().
  * @chan_id: channel ID for sysfs
  * @dev: class device for sysfs
  * @name: backlink name for sysfs
@@ -340,6 +342,7 @@ struct dma_chan {
 	struct device *slave;
 	dma_cookie_t cookie;
 	dma_cookie_t completed_cookie;
+	struct mutex lock; /* protect between config and prepare transfer */
 
 	/* sysfs */
 	int chan_id;
@@ -1068,6 +1071,56 @@ dmaengine_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 	return dmaengine_prep_config_sg(chan, sgl, sg_len, dir, flags, NULL);
 }
 
+/*
+ * dmaengine_prep_config_single(sg)_safe() is re-entrant version.
+ *
+ * The unsafe variant (without the _safe suffix) falls back to calling
+ * dmaengine_slave_config() and dmaengine_prep_slave_sg() separately.
+ * In this case, additional locking may be required, depending on the
+ * DMA consumer's usage.
+ *
+ * If dmaengine driver have not implemented call back device_prep_config_sg()
+ * safe version use per-channel mutex to protect call dmaengine_slave_config()
+ * and dmaengine_prep_slave_sg().
+ */
+static inline struct dma_async_tx_descriptor *
+dmaengine_prep_config_sg_safe(struct dma_chan *chan, struct scatterlist *sgl,
+			      unsigned int sg_len,
+			      enum dma_transfer_direction dir,
+			      unsigned long flags,
+			      struct dma_slave_config *config)
+{
+	struct dma_async_tx_descriptor *tx;
+
+	if (!chan || !chan->device)
+		return NULL;
+
+	if (!chan->device->device_prep_config_sg)
+		mutex_lock(&chan->lock);
+
+	tx = dmaengine_prep_config_sg(chan, sgl, sg_len, dir, flags, config);
+
+	if (!chan->device->device_prep_config_sg)
+		mutex_unlock(&chan->lock);
+
+	return tx;
+}
+
+static inline struct dma_async_tx_descriptor *
+dmaengine_prep_config_single_safe(struct dma_chan *chan, dma_addr_t buf,
+				  size_t len, enum dma_transfer_direction dir,
+				  unsigned long flags,
+				  struct dma_slave_config *config)
+{
+	struct scatterlist sg;
+
+	sg_init_table(&sg, 1);
+	sg_dma_address(&sg) = buf;
+	sg_dma_len(&sg) = len;
+
+	return dmaengine_prep_config_sg_safe(chan, &sg, 1, dir, flags, config);
+}
+
 #ifdef CONFIG_RAPIDIO_DMA_ENGINE
 struct rio_dma_ext;
 static inline struct dma_async_tx_descriptor *dmaengine_prep_rio_sg(

-- 
2.34.1

[PATCH v3 3/9] PCI: endpoint: pci-epf-test: Use dmaenigne_prep_config_single() to simplify code

[Frank Li]

Use dmaenigne_prep_config_single() to simplify code.

No functional change.

Tested-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change in v3
- add Damien Le Moal review tag
---
 drivers/pci/endpoint/functions/pci-epf-test.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
index debd235253c5ba54eb8f06d13261c407ee3768ec..95b046c678da7ca4a0d9616acdd544251dc05aac 100644
--- a/drivers/pci/endpoint/functions/pci-epf-test.c
+++ b/drivers/pci/endpoint/functions/pci-epf-test.c
@@ -162,12 +162,8 @@ static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test,
 		else
 			sconf.src_addr = dma_remote;
 
-		if (dmaengine_slave_config(chan, &sconf)) {
-			dev_err(dev, "DMA slave config fail\n");
-			return -EIO;
-		}
-		tx = dmaengine_prep_slave_single(chan, dma_local, len, dir,
-						 flags);
+		tx = dmaengine_prep_config_single(chan, dma_local, len,
+						  dir, flags, &sconf);
 	} else {
 		tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len,
 					       flags);

-- 
2.34.1

[PATCH v3 4/9] dmaengine: dw-edma: Use new .device_prep_config_sg() callback

[Frank Li]

Use the new .device_prep_config_sg() callback to combine configuration and
descriptor preparation.

No functional changes.

Tested-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change in v3
- add Damien Le Moal review tag
---
 drivers/dma/dw-edma/dw-edma-core.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index 8e5f7defa6b678eefe0f312ebc59f654677c744f..e005b7bdaee156a3f4573b4734f50e3e47553dd2 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -532,10 +532,11 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 }
 
 static struct dma_async_tx_descriptor *
-dw_edma_device_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
-			     unsigned int len,
-			     enum dma_transfer_direction direction,
-			     unsigned long flags, void *context)
+dw_edma_device_prep_config_sg(struct dma_chan *dchan, struct scatterlist *sgl,
+			      unsigned int len,
+			      enum dma_transfer_direction direction,
+			      unsigned long flags,
+			      struct dma_slave_config *config, void *context)
 {
 	struct dw_edma_transfer xfer;
 
@@ -546,6 +547,9 @@ dw_edma_device_prep_slave_sg(struct dma_chan *dchan, struct scatterlist *sgl,
 	xfer.flags = flags;
 	xfer.type = EDMA_XFER_SCATTER_GATHER;
 
+	if (config)
+		dw_edma_device_config(dchan, config);
+
 	return dw_edma_device_transfer(&xfer);
 }
 
@@ -815,7 +819,7 @@ static int dw_edma_channel_setup(struct dw_edma *dw, u32 wr_alloc, u32 rd_alloc)
 	dma->device_terminate_all = dw_edma_device_terminate_all;
 	dma->device_issue_pending = dw_edma_device_issue_pending;
 	dma->device_tx_status = dw_edma_device_tx_status;
-	dma->device_prep_slave_sg = dw_edma_device_prep_slave_sg;
+	dma->device_prep_config_sg = dw_edma_device_prep_config_sg;
 	dma->device_prep_dma_cyclic = dw_edma_device_prep_dma_cyclic;
 	dma->device_prep_interleaved_dma = dw_edma_device_prep_interleaved_dma;
 

-- 
2.34.1

[PATCH v3 5/9] dmaengine: dw-edma: Pass dma_slave_config to dw_edma_device_transfer()

[Frank Li]

Pass dma_slave_config to dw_edma_device_transfer() to support atomic
configuration and descriptor preparation when a non-NULL config is
provided to device_prep_config_sg().

Tested-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
change in v3
- rewrite dw_edma_device_slave_config() according to Damien's suggestion.
---
 drivers/dma/dw-edma/dw-edma-core.c | 27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

diff --git a/drivers/dma/dw-edma/dw-edma-core.c b/drivers/dma/dw-edma/dw-edma-core.c
index e005b7bdaee156a3f4573b4734f50e3e47553dd2..71823c84639801a7ccf944c00ae54f1bcb068d96 100644
--- a/drivers/dma/dw-edma/dw-edma-core.c
+++ b/drivers/dma/dw-edma/dw-edma-core.c
@@ -230,6 +230,20 @@ static int dw_edma_device_config(struct dma_chan *dchan,
 	return 0;
 }
 
+static struct dma_slave_config *
+dw_edma_device_get_config(struct dma_chan *dchan,
+			  struct dma_slave_config *config)
+{
+	struct dw_edma_chan *chan;
+
+	if (config)
+		return config;
+
+	chan = dchan2dw_edma_chan(dchan);
+
+	return &chan->config;
+}
+
 static int dw_edma_device_pause(struct dma_chan *dchan)
 {
 	struct dw_edma_chan *chan = dchan2dw_edma_chan(dchan);
@@ -348,7 +362,8 @@ dw_edma_device_tx_status(struct dma_chan *dchan, dma_cookie_t cookie,
 }
 
 static struct dma_async_tx_descriptor *
-dw_edma_device_transfer(struct dw_edma_transfer *xfer)
+dw_edma_device_transfer(struct dw_edma_transfer *xfer,
+			struct dma_slave_config *config)
 {
 	struct dw_edma_chan *chan = dchan2dw_edma_chan(xfer->dchan);
 	enum dma_transfer_direction dir = xfer->direction;
@@ -427,8 +442,8 @@ dw_edma_device_transfer(struct dw_edma_transfer *xfer)
 		src_addr = xfer->xfer.il->src_start;
 		dst_addr = xfer->xfer.il->dst_start;
 	} else {
-		src_addr = chan->config.src_addr;
-		dst_addr = chan->config.dst_addr;
+		src_addr = config->src_addr;
+		dst_addr = config->dst_addr;
 	}
 
 	if (dir == DMA_DEV_TO_MEM)
@@ -550,7 +565,7 @@ dw_edma_device_prep_config_sg(struct dma_chan *dchan, struct scatterlist *sgl,
 	if (config)
 		dw_edma_device_config(dchan, config);
 
-	return dw_edma_device_transfer(&xfer);
+	return dw_edma_device_transfer(&xfer, dw_edma_device_get_config(dchan, config));
 }
 
 static struct dma_async_tx_descriptor *
@@ -569,7 +584,7 @@ dw_edma_device_prep_dma_cyclic(struct dma_chan *dchan, dma_addr_t paddr,
 	xfer.flags = flags;
 	xfer.type = EDMA_XFER_CYCLIC;
 
-	return dw_edma_device_transfer(&xfer);
+	return dw_edma_device_transfer(&xfer, dw_edma_device_get_config(dchan, NULL));
 }
 
 static struct dma_async_tx_descriptor *
@@ -585,7 +600,7 @@ dw_edma_device_prep_interleaved_dma(struct dma_chan *dchan,
 	xfer.flags = flags;
 	xfer.type = EDMA_XFER_INTERLEAVED;
 
-	return dw_edma_device_transfer(&xfer);
+	return dw_edma_device_transfer(&xfer, dw_edma_device_get_config(dchan, NULL));
 }
 
 static void dw_hdma_set_callback_result(struct virt_dma_desc *vd,

-- 
2.34.1

[PATCH v3 6/9] nvmet: pci-epf: Remove unnecessary dmaengine_terminate_sync() on each DMA transfer

[Frank Li]

dmaengine_terminate_sync() cancels all pending requests. Calling it for
every DMA transfer is unnecessary and counterproductive. This function is
generally intended for cleanup paths such as module removal, device close,
or unbind operations.

Remove the redundant calls for success path and keep it only at error path.

Tested-by: Niklas Cassel <cassel@kernel.org>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
This one also fix stress test failure after remove mutex and use new API
dmaengine_prep_slave_sg_config().
---
 drivers/nvme/target/pci-epf.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/nvme/target/pci-epf.c b/drivers/nvme/target/pci-epf.c
index f858a6c9d7cb90670037a957cebdcbf17dddc43b..56b1c6a7706a9e2dd9d8aaf17b440129b948486c 100644
--- a/drivers/nvme/target/pci-epf.c
+++ b/drivers/nvme/target/pci-epf.c
@@ -420,10 +420,9 @@ static int nvmet_pci_epf_dma_transfer(struct nvmet_pci_epf *nvme_epf,
 	if (dma_sync_wait(chan, cookie) != DMA_COMPLETE) {
 		dev_err(dev, "DMA transfer failed\n");
 		ret = -EIO;
+		dmaengine_terminate_sync(chan);
 	}
 
-	dmaengine_terminate_sync(chan);
-
 unmap:
 	dma_unmap_single(dma_dev, dma_addr, seg->length, dir);
 

-- 
2.34.1

[PATCH v3 7/9] nvmet: pci-epf: Use dmaengine_prep_config_single_safe() API

[Frank Li]

Use the new dmaengine_prep_config_single_safe() API to combine the
configuration and descriptor preparation into a single call.

Since dmaengine_prep_config_single_safe() performs the configuration and
preparation atomically and the mutex can be removed.

Tested-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/nvme/target/pci-epf.c | 18 ++++--------------
 1 file changed, 4 insertions(+), 14 deletions(-)

diff --git a/drivers/nvme/target/pci-epf.c b/drivers/nvme/target/pci-epf.c
index 56b1c6a7706a9e2dd9d8aaf17b440129b948486c..8b5ea5d4c79dfd461b767cfd4033a9e4604c94b1 100644
--- a/drivers/nvme/target/pci-epf.c
+++ b/drivers/nvme/target/pci-epf.c
@@ -388,22 +388,15 @@ static int nvmet_pci_epf_dma_transfer(struct nvmet_pci_epf *nvme_epf,
 		return -EINVAL;
 	}
 
-	mutex_lock(lock);
-
 	dma_dev = dmaengine_get_dma_device(chan);
 	dma_addr = dma_map_single(dma_dev, seg->buf, seg->length, dir);
 	ret = dma_mapping_error(dma_dev, dma_addr);
 	if (ret)
-		goto unlock;
-
-	ret = dmaengine_slave_config(chan, &sconf);
-	if (ret) {
-		dev_err(dev, "Failed to configure DMA channel\n");
-		goto unmap;
-	}
+		return ret;
 
-	desc = dmaengine_prep_slave_single(chan, dma_addr, seg->length,
-					   sconf.direction, DMA_CTRL_ACK);
+	desc = dmaengine_prep_config_single_safe(chan, dma_addr, seg->length,
+						 sconf.direction,
+						 DMA_CTRL_ACK, &sconf);
 	if (!desc) {
 		dev_err(dev, "Failed to prepare DMA\n");
 		ret = -EIO;
@@ -426,9 +419,6 @@ static int nvmet_pci_epf_dma_transfer(struct nvmet_pci_epf *nvme_epf,
 unmap:
 	dma_unmap_single(dma_dev, dma_addr, seg->length, dir);
 
-unlock:
-	mutex_unlock(lock);
-
 	return ret;
 }
 

-- 
2.34.1

[PATCH v3 8/9] PCI: epf-mhi: Use dmaengine_prep_config_single() to simplify code

[Frank Li]

Use dmaengine_prep_config_single() to simplify
pci_epf_mhi_edma_read[_sync]() and pci_epf_mhi_edma_write[_sync]().

No functional change.

Tested-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
Keep mutex lock because sync with other function.
---
 drivers/pci/endpoint/functions/pci-epf-mhi.c | 52 +++++++++-------------------
 1 file changed, 16 insertions(+), 36 deletions(-)

diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c
index 6643a88c7a0ce38161bc6253c09d29f1c36ba394..0bf51fd467395182161555f83aa78f3839e36773 100644
--- a/drivers/pci/endpoint/functions/pci-epf-mhi.c
+++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c
@@ -328,12 +328,6 @@ static int pci_epf_mhi_edma_read(struct mhi_ep_cntrl *mhi_cntrl,
 	config.direction = DMA_DEV_TO_MEM;
 	config.src_addr = buf_info->host_addr;
 
-	ret = dmaengine_slave_config(chan, &config);
-	if (ret) {
-		dev_err(dev, "Failed to configure DMA channel\n");
-		goto err_unlock;
-	}
-
 	dst_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
 				  DMA_FROM_DEVICE);
 	ret = dma_mapping_error(dma_dev, dst_addr);
@@ -342,9 +336,10 @@ static int pci_epf_mhi_edma_read(struct mhi_ep_cntrl *mhi_cntrl,
 		goto err_unlock;
 	}
 
-	desc = dmaengine_prep_slave_single(chan, dst_addr, buf_info->size,
-					   DMA_DEV_TO_MEM,
-					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
+	desc = dmaengine_prep_config_single(chan, dst_addr, buf_info->size,
+					    DMA_DEV_TO_MEM,
+					    DMA_CTRL_ACK | DMA_PREP_INTERRUPT,
+					    &config);
 	if (!desc) {
 		dev_err(dev, "Failed to prepare DMA\n");
 		ret = -EIO;
@@ -399,12 +394,6 @@ static int pci_epf_mhi_edma_write(struct mhi_ep_cntrl *mhi_cntrl,
 	config.direction = DMA_MEM_TO_DEV;
 	config.dst_addr = buf_info->host_addr;
 
-	ret = dmaengine_slave_config(chan, &config);
-	if (ret) {
-		dev_err(dev, "Failed to configure DMA channel\n");
-		goto err_unlock;
-	}
-
 	src_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
 				  DMA_TO_DEVICE);
 	ret = dma_mapping_error(dma_dev, src_addr);
@@ -413,9 +402,10 @@ static int pci_epf_mhi_edma_write(struct mhi_ep_cntrl *mhi_cntrl,
 		goto err_unlock;
 	}
 
-	desc = dmaengine_prep_slave_single(chan, src_addr, buf_info->size,
-					   DMA_MEM_TO_DEV,
-					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
+	desc = dmaengine_prep_config_single(chan, src_addr, buf_info->size,
+					    DMA_MEM_TO_DEV,
+					    DMA_CTRL_ACK | DMA_PREP_INTERRUPT,
+					    &config);
 	if (!desc) {
 		dev_err(dev, "Failed to prepare DMA\n");
 		ret = -EIO;
@@ -502,12 +492,6 @@ static int pci_epf_mhi_edma_read_async(struct mhi_ep_cntrl *mhi_cntrl,
 	config.direction = DMA_DEV_TO_MEM;
 	config.src_addr = buf_info->host_addr;
 
-	ret = dmaengine_slave_config(chan, &config);
-	if (ret) {
-		dev_err(dev, "Failed to configure DMA channel\n");
-		goto err_unlock;
-	}
-
 	dst_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
 				  DMA_FROM_DEVICE);
 	ret = dma_mapping_error(dma_dev, dst_addr);
@@ -516,9 +500,10 @@ static int pci_epf_mhi_edma_read_async(struct mhi_ep_cntrl *mhi_cntrl,
 		goto err_unlock;
 	}
 
-	desc = dmaengine_prep_slave_single(chan, dst_addr, buf_info->size,
-					   DMA_DEV_TO_MEM,
-					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
+	desc = dmaengine_prep_config_single(chan, dst_addr, buf_info->size,
+					    DMA_DEV_TO_MEM,
+					    DMA_CTRL_ACK | DMA_PREP_INTERRUPT,
+					    &config);
 	if (!desc) {
 		dev_err(dev, "Failed to prepare DMA\n");
 		ret = -EIO;
@@ -581,12 +566,6 @@ static int pci_epf_mhi_edma_write_async(struct mhi_ep_cntrl *mhi_cntrl,
 	config.direction = DMA_MEM_TO_DEV;
 	config.dst_addr = buf_info->host_addr;
 
-	ret = dmaengine_slave_config(chan, &config);
-	if (ret) {
-		dev_err(dev, "Failed to configure DMA channel\n");
-		goto err_unlock;
-	}
-
 	src_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
 				  DMA_TO_DEVICE);
 	ret = dma_mapping_error(dma_dev, src_addr);
@@ -595,9 +574,10 @@ static int pci_epf_mhi_edma_write_async(struct mhi_ep_cntrl *mhi_cntrl,
 		goto err_unlock;
 	}
 
-	desc = dmaengine_prep_slave_single(chan, src_addr, buf_info->size,
-					   DMA_MEM_TO_DEV,
-					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
+	desc = dmaengine_prep_config_single(chan, src_addr, buf_info->size,
+					    DMA_MEM_TO_DEV,
+					    DMA_CTRL_ACK | DMA_PREP_INTERRUPT,
+					    &config);
 	if (!desc) {
 		dev_err(dev, "Failed to prepare DMA\n");
 		ret = -EIO;

-- 
2.34.1

[PATCH v3 9/9] crypto: atmel: Use dmaengine_prep_config_single() API

[Frank Li]

Using new API dmaengine_prep_config_single() to simple code.

No functional change.

Tested-by: Niklas Cassel <cassel@kernel.org>
Signed-off-by: Frank Li <Frank.Li@nxp.com>
---
 drivers/crypto/atmel-aes.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/crypto/atmel-aes.c b/drivers/crypto/atmel-aes.c
index 3a2684208dda9ee45d71b4bc2958be293a4fb6fe..e300672ffd7185b0f5bf356c2376681537047def 100644
--- a/drivers/crypto/atmel-aes.c
+++ b/drivers/crypto/atmel-aes.c
@@ -795,7 +795,6 @@ static int atmel_aes_dma_transfer_start(struct atmel_aes_dev *dd,
 	struct dma_slave_config config;
 	dma_async_tx_callback callback;
 	struct atmel_aes_dma *dma;
-	int err;
 
 	memset(&config, 0, sizeof(config));
 	config.src_addr_width = addr_width;
@@ -820,12 +819,9 @@ static int atmel_aes_dma_transfer_start(struct atmel_aes_dev *dd,
 		return -EINVAL;
 	}
 
-	err = dmaengine_slave_config(dma->chan, &config);
-	if (err)
-		return err;
-
-	desc = dmaengine_prep_slave_sg(dma->chan, dma->sg, dma->sg_len, dir,
-				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+	desc = dmaengine_prep_config_sg(dma->chan, dma->sg, dma->sg_len, dir,
+					DMA_PREP_INTERRUPT | DMA_CTRL_ACK,
+					&config);
 	if (!desc)
 		return -ENOMEM;
 

-- 
2.34.1

Re: [PATCH v3 0/9] dmaengine: Add new API to combine configuration and descriptor preparation

[Niklas Cassel]

Frank,

Thanks a lot for your work on this series!

On Mon, Jan 05, 2026 at 05:46:50PM -0500, Frank Li wrote:
>  Documentation/driver-api/dmaengine/client.rst |   9 ++
>  drivers/crypto/atmel-aes.c                    |  10 +--
>  drivers/dma/dmaengine.c                       |   3 +
>  drivers/dma/dw-edma/dw-edma-core.c            |  41 ++++++---
>  drivers/nvme/target/pci-epf.c                 |  21 ++---
>  drivers/pci/endpoint/functions/pci-epf-mhi.c  |  52 ++++--------
>  drivers/pci/endpoint/functions/pci-epf-test.c |   8 +-
>  include/linux/dmaengine.h                     | 117 ++++++++++++++++++++++++--
>  8 files changed, 177 insertions(+), 84 deletions(-)

Is the plan to merge this series via the dmaengine tree?

If so, we might need an Ack from Mani on the pci-epf-mhi.c and
pci-epf-test.c patch.

Likewise we might need an Ack from Keith/Christoph on the
drivers/nvme/target/pci-epf.c patches.


Kind regards,
Niklas

Re: [PATCH v3 3/9] PCI: endpoint: pci-epf-test: Use dmaenigne_prep_config_single() to simplify code

[Manivannan Sadhasivam]

On Mon, Jan 05, 2026 at 05:46:53PM -0500, Frank Li wrote:
> Use dmaenigne_prep_config_single() to simplify code.
> 
> No functional change.
> 
> Tested-by: Niklas Cassel <cassel@kernel.org>
> Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>

Acked-by: Manivannan Sadhasivam <mani@kernel.org>

- Mani

> ---
> change in v3
> - add Damien Le Moal review tag
> ---
>  drivers/pci/endpoint/functions/pci-epf-test.c | 8 ++------
>  1 file changed, 2 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-test.c b/drivers/pci/endpoint/functions/pci-epf-test.c
> index debd235253c5ba54eb8f06d13261c407ee3768ec..95b046c678da7ca4a0d9616acdd544251dc05aac 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-test.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-test.c
> @@ -162,12 +162,8 @@ static int pci_epf_test_data_transfer(struct pci_epf_test *epf_test,
>  		else
>  			sconf.src_addr = dma_remote;
>  
> -		if (dmaengine_slave_config(chan, &sconf)) {
> -			dev_err(dev, "DMA slave config fail\n");
> -			return -EIO;
> -		}
> -		tx = dmaengine_prep_slave_single(chan, dma_local, len, dir,
> -						 flags);
> +		tx = dmaengine_prep_config_single(chan, dma_local, len,
> +						  dir, flags, &sconf);
>  	} else {
>  		tx = dmaengine_prep_dma_memcpy(chan, dma_dst, dma_src, len,
>  					       flags);
> 
> -- 
> 2.34.1
> 

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v3 8/9] PCI: epf-mhi: Use dmaengine_prep_config_single() to simplify code

[Manivannan Sadhasivam]

On Mon, Jan 05, 2026 at 05:46:58PM -0500, Frank Li wrote:
> Use dmaengine_prep_config_single() to simplify
> pci_epf_mhi_edma_read[_sync]() and pci_epf_mhi_edma_write[_sync]().
> 
> No functional change.
> 
> Tested-by: Niklas Cassel <cassel@kernel.org>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>

Acked-by: Manivannan Sadhasivam <mani@kernel.org>

- Mani

> ---
> Keep mutex lock because sync with other function.
> ---
>  drivers/pci/endpoint/functions/pci-epf-mhi.c | 52 +++++++++-------------------
>  1 file changed, 16 insertions(+), 36 deletions(-)
> 
> diff --git a/drivers/pci/endpoint/functions/pci-epf-mhi.c b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> index 6643a88c7a0ce38161bc6253c09d29f1c36ba394..0bf51fd467395182161555f83aa78f3839e36773 100644
> --- a/drivers/pci/endpoint/functions/pci-epf-mhi.c
> +++ b/drivers/pci/endpoint/functions/pci-epf-mhi.c
> @@ -328,12 +328,6 @@ static int pci_epf_mhi_edma_read(struct mhi_ep_cntrl *mhi_cntrl,
>  	config.direction = DMA_DEV_TO_MEM;
>  	config.src_addr = buf_info->host_addr;
>  
> -	ret = dmaengine_slave_config(chan, &config);
> -	if (ret) {
> -		dev_err(dev, "Failed to configure DMA channel\n");
> -		goto err_unlock;
> -	}
> -
>  	dst_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
>  				  DMA_FROM_DEVICE);
>  	ret = dma_mapping_error(dma_dev, dst_addr);
> @@ -342,9 +336,10 @@ static int pci_epf_mhi_edma_read(struct mhi_ep_cntrl *mhi_cntrl,
>  		goto err_unlock;
>  	}
>  
> -	desc = dmaengine_prep_slave_single(chan, dst_addr, buf_info->size,
> -					   DMA_DEV_TO_MEM,
> -					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
> +	desc = dmaengine_prep_config_single(chan, dst_addr, buf_info->size,
> +					    DMA_DEV_TO_MEM,
> +					    DMA_CTRL_ACK | DMA_PREP_INTERRUPT,
> +					    &config);
>  	if (!desc) {
>  		dev_err(dev, "Failed to prepare DMA\n");
>  		ret = -EIO;
> @@ -399,12 +394,6 @@ static int pci_epf_mhi_edma_write(struct mhi_ep_cntrl *mhi_cntrl,
>  	config.direction = DMA_MEM_TO_DEV;
>  	config.dst_addr = buf_info->host_addr;
>  
> -	ret = dmaengine_slave_config(chan, &config);
> -	if (ret) {
> -		dev_err(dev, "Failed to configure DMA channel\n");
> -		goto err_unlock;
> -	}
> -
>  	src_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
>  				  DMA_TO_DEVICE);
>  	ret = dma_mapping_error(dma_dev, src_addr);
> @@ -413,9 +402,10 @@ static int pci_epf_mhi_edma_write(struct mhi_ep_cntrl *mhi_cntrl,
>  		goto err_unlock;
>  	}
>  
> -	desc = dmaengine_prep_slave_single(chan, src_addr, buf_info->size,
> -					   DMA_MEM_TO_DEV,
> -					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
> +	desc = dmaengine_prep_config_single(chan, src_addr, buf_info->size,
> +					    DMA_MEM_TO_DEV,
> +					    DMA_CTRL_ACK | DMA_PREP_INTERRUPT,
> +					    &config);
>  	if (!desc) {
>  		dev_err(dev, "Failed to prepare DMA\n");
>  		ret = -EIO;
> @@ -502,12 +492,6 @@ static int pci_epf_mhi_edma_read_async(struct mhi_ep_cntrl *mhi_cntrl,
>  	config.direction = DMA_DEV_TO_MEM;
>  	config.src_addr = buf_info->host_addr;
>  
> -	ret = dmaengine_slave_config(chan, &config);
> -	if (ret) {
> -		dev_err(dev, "Failed to configure DMA channel\n");
> -		goto err_unlock;
> -	}
> -
>  	dst_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
>  				  DMA_FROM_DEVICE);
>  	ret = dma_mapping_error(dma_dev, dst_addr);
> @@ -516,9 +500,10 @@ static int pci_epf_mhi_edma_read_async(struct mhi_ep_cntrl *mhi_cntrl,
>  		goto err_unlock;
>  	}
>  
> -	desc = dmaengine_prep_slave_single(chan, dst_addr, buf_info->size,
> -					   DMA_DEV_TO_MEM,
> -					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
> +	desc = dmaengine_prep_config_single(chan, dst_addr, buf_info->size,
> +					    DMA_DEV_TO_MEM,
> +					    DMA_CTRL_ACK | DMA_PREP_INTERRUPT,
> +					    &config);
>  	if (!desc) {
>  		dev_err(dev, "Failed to prepare DMA\n");
>  		ret = -EIO;
> @@ -581,12 +566,6 @@ static int pci_epf_mhi_edma_write_async(struct mhi_ep_cntrl *mhi_cntrl,
>  	config.direction = DMA_MEM_TO_DEV;
>  	config.dst_addr = buf_info->host_addr;
>  
> -	ret = dmaengine_slave_config(chan, &config);
> -	if (ret) {
> -		dev_err(dev, "Failed to configure DMA channel\n");
> -		goto err_unlock;
> -	}
> -
>  	src_addr = dma_map_single(dma_dev, buf_info->dev_addr, buf_info->size,
>  				  DMA_TO_DEVICE);
>  	ret = dma_mapping_error(dma_dev, src_addr);
> @@ -595,9 +574,10 @@ static int pci_epf_mhi_edma_write_async(struct mhi_ep_cntrl *mhi_cntrl,
>  		goto err_unlock;
>  	}
>  
> -	desc = dmaengine_prep_slave_single(chan, src_addr, buf_info->size,
> -					   DMA_MEM_TO_DEV,
> -					   DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
> +	desc = dmaengine_prep_config_single(chan, src_addr, buf_info->size,
> +					    DMA_MEM_TO_DEV,
> +					    DMA_CTRL_ACK | DMA_PREP_INTERRUPT,
> +					    &config);
>  	if (!desc) {
>  		dev_err(dev, "Failed to prepare DMA\n");
>  		ret = -EIO;
> 
> -- 
> 2.34.1
> 

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v3 0/9] dmaengine: Add new API to combine configuration and descriptor preparation

[Manivannan Sadhasivam]

On Mon, Jan 12, 2026 at 02:01:32PM +0100, Niklas Cassel wrote:
> Frank,
> 
> Thanks a lot for your work on this series!
> 
> On Mon, Jan 05, 2026 at 05:46:50PM -0500, Frank Li wrote:
> >  Documentation/driver-api/dmaengine/client.rst |   9 ++
> >  drivers/crypto/atmel-aes.c                    |  10 +--
> >  drivers/dma/dmaengine.c                       |   3 +
> >  drivers/dma/dw-edma/dw-edma-core.c            |  41 ++++++---
> >  drivers/nvme/target/pci-epf.c                 |  21 ++---
> >  drivers/pci/endpoint/functions/pci-epf-mhi.c  |  52 ++++--------
> >  drivers/pci/endpoint/functions/pci-epf-test.c |   8 +-
> >  include/linux/dmaengine.h                     | 117 ++++++++++++++++++++++++--
> >  8 files changed, 177 insertions(+), 84 deletions(-)
> 
> Is the plan to merge this series via the dmaengine tree?
> 

It makes sense to take it through dmaengine tree given that the changes in PCI
and other drivers are straightforward.

> If so, we might need an Ack from Mani on the pci-epf-mhi.c and
> pci-epf-test.c patch.
> 

Just did.

- Mani

-- 
மணிவண்ணன் சதாசிவம்

Re: [PATCH v3 9/9] crypto: atmel: Use dmaengine_prep_config_single() API

[Nicolas Ferre]

On 05/01/2026 at 23:46, Frank Li wrote:
> Using new API dmaengine_prep_config_single() to simple code.
> 
> No functional change.
> 
> Tested-by: Niklas Cassel <cassel@kernel.org>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>

Looks good to me:
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>

Thanks, best regards,
   Nicolas

> ---
>   drivers/crypto/atmel-aes.c | 10 +++-------
>   1 file changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/crypto/atmel-aes.c b/drivers/crypto/atmel-aes.c
> index 3a2684208dda9ee45d71b4bc2958be293a4fb6fe..e300672ffd7185b0f5bf356c2376681537047def 100644
> --- a/drivers/crypto/atmel-aes.c
> +++ b/drivers/crypto/atmel-aes.c
> @@ -795,7 +795,6 @@ static int atmel_aes_dma_transfer_start(struct atmel_aes_dev *dd,
>          struct dma_slave_config config;
>          dma_async_tx_callback callback;
>          struct atmel_aes_dma *dma;
> -       int err;
> 
>          memset(&config, 0, sizeof(config));
>          config.src_addr_width = addr_width;
> @@ -820,12 +819,9 @@ static int atmel_aes_dma_transfer_start(struct atmel_aes_dev *dd,
>                  return -EINVAL;
>          }
> 
> -       err = dmaengine_slave_config(dma->chan, &config);
> -       if (err)
> -               return err;
> -
> -       desc = dmaengine_prep_slave_sg(dma->chan, dma->sg, dma->sg_len, dir,
> -                                      DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
> +       desc = dmaengine_prep_config_sg(dma->chan, dma->sg, dma->sg_len, dir,
> +                                       DMA_PREP_INTERRUPT | DMA_CTRL_ACK,
> +                                       &config);
>          if (!desc)
>                  return -ENOMEM;
> 
> 
> --
> 2.34.1
> 

Re: [PATCH v3 0/9] dmaengine: Add new API to combine configuration and descriptor preparation

[Frank Li]

On Mon, Jan 05, 2026 at 05:46:50PM -0500, Frank Li wrote:
> Previously, configuration and preparation required two separate calls. This
> works well when configuration is done only once during initialization.
>
> However, in cases where the burst length or source/destination address must
> be adjusted for each transfer, calling two functions is verbose.
>
> 	if (dmaengine_slave_config(chan, &sconf)) {
> 		dev_err(dev, "DMA slave config fail\n");
> 		return -EIO;
> 	}
>
> 	tx = dmaengine_prep_slave_single(chan, dma_local, len, dir, flags);
>
> After new API added
>
> 	tx = dmaengine_prep_config_single(chan, dma_local, len, dir, flags, &sconf);
>
> Additional, prevous two calls requires additional locking to ensure both
> steps complete atomically.
>
>     mutex_lock()
>     dmaengine_slave_config()
>     dmaengine_prep_slave_single()
>     mutex_unlock()
>
> after new API added, mutex lock can be moved. See patch
>      nvmet: pci-epf: Use dmaengine_prep_config_single_safe() API
>
> Signed-off-by: Frank Li <Frank.Li@nxp.com>
> ---

Vinod:
	Can you take care these patches? At least first 2 patches! So
I can did more clean up at next kernel release.

Frank

> Changes in v3:
> - collect review tags
> - create safe version in framework
> - Link to v2: https://lore.kernel.org/r/20251218-dma_prep_config-v2-0-c07079836128@nxp.com
>
> Changes in v2:
> - Use name dmaengine_prep_config_single() and dmaengine_prep_config_sg()
> - Add _safe version to avoid confuse, which needn't additional mutex.
> - Update document/
> - Update commit message. add () for function name. Use upcase for subject.
> - Add more explain for remove lock.
> - Link to v1: https://lore.kernel.org/r/20251208-dma_prep_config-v1-0-53490c5e1e2a@nxp.com
>
> ---
> Frank Li (9):
>       dmaengine: Add API to combine configuration and preparation (sg and single)
>       dmaengine: Add safe API to combine configuration and preparation
>       PCI: endpoint: pci-epf-test: Use dmaenigne_prep_config_single() to simplify code
>       dmaengine: dw-edma: Use new .device_prep_config_sg() callback
>       dmaengine: dw-edma: Pass dma_slave_config to dw_edma_device_transfer()
>       nvmet: pci-epf: Remove unnecessary dmaengine_terminate_sync() on each DMA transfer
>       nvmet: pci-epf: Use dmaengine_prep_config_single_safe() API
>       PCI: epf-mhi: Use dmaengine_prep_config_single() to simplify code
>       crypto: atmel: Use dmaengine_prep_config_single() API
>
>  Documentation/driver-api/dmaengine/client.rst |   9 ++
>  drivers/crypto/atmel-aes.c                    |  10 +--
>  drivers/dma/dmaengine.c                       |   3 +
>  drivers/dma/dw-edma/dw-edma-core.c            |  41 ++++++---
>  drivers/nvme/target/pci-epf.c                 |  21 ++---
>  drivers/pci/endpoint/functions/pci-epf-mhi.c  |  52 ++++--------
>  drivers/pci/endpoint/functions/pci-epf-test.c |   8 +-
>  include/linux/dmaengine.h                     | 117 ++++++++++++++++++++++++--
>  8 files changed, 177 insertions(+), 84 deletions(-)
> ---
> base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
> change-id: 20251204-dma_prep_config-654170d245a2
>
> Best regards,
> --
> Frank Li <Frank.Li@nxp.com>
>

Re: [PATCH v3 0/9] dmaengine: Add new API to combine configuration and descriptor preparation

[Frank Li]

On Wed, Jan 21, 2026 at 11:30:09AM -0500, Frank Li wrote:
> On Mon, Jan 05, 2026 at 05:46:50PM -0500, Frank Li wrote:
> > Previously, configuration and preparation required two separate calls. This
> > works well when configuration is done only once during initialization.
> >
> > However, in cases where the burst length or source/destination address must
> > be adjusted for each transfer, calling two functions is verbose.
> >
> > 	if (dmaengine_slave_config(chan, &sconf)) {
> > 		dev_err(dev, "DMA slave config fail\n");
> > 		return -EIO;
> > 	}
> >
> > 	tx = dmaengine_prep_slave_single(chan, dma_local, len, dir, flags);
> >
> > After new API added
> >
> > 	tx = dmaengine_prep_config_single(chan, dma_local, len, dir, flags, &sconf);
> >
> > Additional, prevous two calls requires additional locking to ensure both
> > steps complete atomically.
> >
> >     mutex_lock()
> >     dmaengine_slave_config()
> >     dmaengine_prep_slave_single()
> >     mutex_unlock()
> >
> > after new API added, mutex lock can be moved. See patch
> >      nvmet: pci-epf: Use dmaengine_prep_config_single_safe() API
> >
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
>
> Vinod:
> 	Can you take care these patches? At least first 2 patches! So
> I can did more clean up at next kernel release.

Vinod Koul:

	Do you have chance to pick up (at least first 2 patches) for 6.20?
So I can start do more cleanup work.

	There are two serial depend on this one

https://lore.kernel.org/dmaengine/20251212-edma_ll-v1-0-fc863d9f5ca3@nxp.com/
https://lore.kernel.org/dmaengine/aWT4p7RnFykJnuOz@ryzen/

Frank

>
> Frank
>
> > Changes in v3:
> > - collect review tags
> > - create safe version in framework
> > - Link to v2: https://lore.kernel.org/r/20251218-dma_prep_config-v2-0-c07079836128@nxp.com
> >
> > Changes in v2:
> > - Use name dmaengine_prep_config_single() and dmaengine_prep_config_sg()
> > - Add _safe version to avoid confuse, which needn't additional mutex.
> > - Update document/
> > - Update commit message. add () for function name. Use upcase for subject.
> > - Add more explain for remove lock.
> > - Link to v1: https://lore.kernel.org/r/20251208-dma_prep_config-v1-0-53490c5e1e2a@nxp.com
> >
> > ---
> > Frank Li (9):
> >       dmaengine: Add API to combine configuration and preparation (sg and single)
> >       dmaengine: Add safe API to combine configuration and preparation
> >       PCI: endpoint: pci-epf-test: Use dmaenigne_prep_config_single() to simplify code
> >       dmaengine: dw-edma: Use new .device_prep_config_sg() callback
> >       dmaengine: dw-edma: Pass dma_slave_config to dw_edma_device_transfer()
> >       nvmet: pci-epf: Remove unnecessary dmaengine_terminate_sync() on each DMA transfer
> >       nvmet: pci-epf: Use dmaengine_prep_config_single_safe() API
> >       PCI: epf-mhi: Use dmaengine_prep_config_single() to simplify code
> >       crypto: atmel: Use dmaengine_prep_config_single() API
> >
> >  Documentation/driver-api/dmaengine/client.rst |   9 ++
> >  drivers/crypto/atmel-aes.c                    |  10 +--
> >  drivers/dma/dmaengine.c                       |   3 +
> >  drivers/dma/dw-edma/dw-edma-core.c            |  41 ++++++---
> >  drivers/nvme/target/pci-epf.c                 |  21 ++---
> >  drivers/pci/endpoint/functions/pci-epf-mhi.c  |  52 ++++--------
> >  drivers/pci/endpoint/functions/pci-epf-test.c |   8 +-
> >  include/linux/dmaengine.h                     | 117 ++++++++++++++++++++++++--
> >  8 files changed, 177 insertions(+), 84 deletions(-)
> > ---
> > base-commit: 8f0b4cce4481fb22653697cced8d0d04027cb1e8
> > change-id: 20251204-dma_prep_config-654170d245a2
> >
> > Best regards,
> > --
> > Frank Li <Frank.Li@nxp.com>
> >

Re: [PATCH v3 0/9] dmaengine: Add new API to combine configuration and descriptor preparation

[Niklas Cassel]

On Fri, Jan 30, 2026 at 02:19:58PM -0500, Frank Li wrote:
> 
> Vinod Koul:
> 
> 	Do you have chance to pick up (at least first 2 patches) for 6.20?
> So I can start do more cleanup work.

Why only the first two patches?

Mani has already given his ack and said that he thinks it should go via
the dmaengine tree:
https://lore.kernel.org/dmaengine/6f4elcu5iql65jeqfeqhmllquv253xh4gb37ivef2kyvsj5lps@w35ciehuwxym/

The series still applies to dmaengine/next btw :)


Kind regards,
Niklas