[PATCH 00/10] dma: mv_xor_v2: fixes and improvements

[PATCH 00/10] dma: mv_xor_v2: fixes and improvements

[Thomas Petazzoni]

Hello,

This series brings a number of fixes (first 7 patches) and
improvements (last 3 patches) to the driver used for the Marvell XORv2
engine used in Marvell Armada 7K/8K.

Thanks,

Thomas

Hanna Hawa (4):
  dma: mv_xor_v2: enable XOR engine after its configuration
  dma: mv_xor_v2: implement proper interrupt coalescing
  dma: mv_xor_v2: remove unnecessary write to DESQ_STOP register
  dma: mv_xor_v2: add support for suspend/resume

Thomas Petazzoni (6):
  dma: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly
  dma: mv_xor_v2: properly handle wrapping in the array of HW
    descriptors
  dma: mv_xor_v2: do not use descriptors not acked by async_tx
  dma: mv_xor_v2: fix tx_submit() implementation
  dma: mv_xor_v2: remove interrupt coalescing
  dma: mv_xor_v2: set DMA mask to 40 bits

 drivers/dma/mv_xor_v2.c | 147 ++++++++++++++++++++++++++++++------------------
 1 file changed, 91 insertions(+), 56 deletions(-)

-- 
2.7.4

[PATCH 01/10] dma: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly

[Thomas Petazzoni]

The mv_xor_v2_prep_sw_desc() is called from a few different places in
the driver, but we never take into account the fact that it might
return NULL. This commit fixes that, ensuring that we don't panic if
there are no more descriptors available.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index a28a01f..e928020 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -389,6 +389,8 @@ mv_xor_v2_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest,
 		__func__, len, &src, &dest, flags);
 
 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
+	if (!sw_desc)
+		return NULL;
 
 	sw_desc->async_tx.flags = flags;
 
@@ -443,6 +445,8 @@ mv_xor_v2_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
 		__func__, src_cnt, len, &dest, flags);
 
 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
+	if (!sw_desc)
+		return NULL;
 
 	sw_desc->async_tx.flags = flags;
 
@@ -491,6 +495,8 @@ mv_xor_v2_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags)
 		container_of(chan, struct mv_xor_v2_device, dmachan);
 
 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
+	if (!sw_desc)
+		return NULL;
 
 	/* set the HW descriptor */
 	hw_descriptor = &sw_desc->hw_desc;
-- 
2.7.4

[PATCH 01/10] dma: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly

[Thomas Petazzoni]

The mv_xor_v2_prep_sw_desc() is called from a few different places in
the driver, but we never take into account the fact that it might
return NULL. This commit fixes that, ensuring that we don't panic if
there are no more descriptors available.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index a28a01f..e928020 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -389,6 +389,8 @@ mv_xor_v2_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest,
 		__func__, len, &src, &dest, flags);
 
 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
+	if (!sw_desc)
+		return NULL;
 
 	sw_desc->async_tx.flags = flags;
 
@@ -443,6 +445,8 @@ mv_xor_v2_prep_dma_xor(struct dma_chan *chan, dma_addr_t dest, dma_addr_t *src,
 		__func__, src_cnt, len, &dest, flags);
 
 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
+	if (!sw_desc)
+		return NULL;
 
 	sw_desc->async_tx.flags = flags;
 
@@ -491,6 +495,8 @@ mv_xor_v2_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags)
 		container_of(chan, struct mv_xor_v2_device, dmachan);
 
 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
+	if (!sw_desc)
+		return NULL;
 
 	/* set the HW descriptor */
 	hw_descriptor = &sw_desc->hw_desc;
-- 
2.7.4

[PATCH 02/10] dma: mv_xor_v2: properly handle wrapping in the array of HW descriptors

mv_xor_v2_tasklet() is looping over completed HW descriptors. Before the
loop, it initializes 'next_pending_hw_desc' to the first HW descriptor
to handle, and then the loop simply increments this point, without
taking care of wrapping when we reach the last HW descriptor. The
'pending_ptr' index was being wrapped back to 0 at the end, but it
wasn't used in each iteration of the loop to calculate
next_pending_hw_desc.

This commit fixes that, and makes next_pending_hw_desc a variable local
to the loop itself.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index e928020..bdfb36e 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -560,7 +560,6 @@ static void mv_xor_v2_tasklet(unsigned long data)
 {
 	struct mv_xor_v2_device *xor_dev = (struct mv_xor_v2_device *) data;
 	int pending_ptr, num_of_pending, i;
-	struct mv_xor_v2_descriptor *next_pending_hw_desc = NULL;
 	struct mv_xor_v2_sw_desc *next_pending_sw_desc = NULL;
 
 	dev_dbg(xor_dev->dmadev.dev, "%s %d\n", __func__, __LINE__);
@@ -568,17 +567,10 @@ static void mv_xor_v2_tasklet(unsigned long data)
 	/* get the pending descriptors parameters */
 	num_of_pending = mv_xor_v2_get_pending_params(xor_dev, &pending_ptr);
 
-	/* next HW descriptor */
-	next_pending_hw_desc = xor_dev->hw_desq_virt + pending_ptr;
-
 	/* loop over free descriptors */
 	for (i = 0; i < num_of_pending; i++) {
-
-		if (pending_ptr > MV_XOR_V2_DESC_NUM)
-			pending_ptr = 0;
-
-		if (next_pending_sw_desc != NULL)
-			next_pending_hw_desc++;
+		struct mv_xor_v2_descriptor *next_pending_hw_desc =
+			xor_dev->hw_desq_virt + pending_ptr;
 
 		/* get the SW descriptor related to the HW descriptor */
 		next_pending_sw_desc =
@@ -614,6 +606,8 @@ static void mv_xor_v2_tasklet(unsigned long data)
 
 		/* increment the next descriptor */
 		pending_ptr++;
+		if (pending_ptr >= MV_XOR_V2_DESC_NUM)
+			pending_ptr = 0;
 	}
 
 	if (num_of_pending != 0) {
-- 
2.7.4

[PATCH 02/10] dma: mv_xor_v2: properly handle wrapping in the array of HW descriptors

[Thomas Petazzoni]

mv_xor_v2_tasklet() is looping over completed HW descriptors. Before the
loop, it initializes 'next_pending_hw_desc' to the first HW descriptor
to handle, and then the loop simply increments this point, without
taking care of wrapping when we reach the last HW descriptor. The
'pending_ptr' index was being wrapped back to 0 at the end, but it
wasn't used in each iteration of the loop to calculate
next_pending_hw_desc.

This commit fixes that, and makes next_pending_hw_desc a variable local
to the loop itself.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 14 ++++----------
 1 file changed, 4 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index e928020..bdfb36e 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -560,7 +560,6 @@ static void mv_xor_v2_tasklet(unsigned long data)
 {
 	struct mv_xor_v2_device *xor_dev = (struct mv_xor_v2_device *) data;
 	int pending_ptr, num_of_pending, i;
-	struct mv_xor_v2_descriptor *next_pending_hw_desc = NULL;
 	struct mv_xor_v2_sw_desc *next_pending_sw_desc = NULL;
 
 	dev_dbg(xor_dev->dmadev.dev, "%s %d\n", __func__, __LINE__);
@@ -568,17 +567,10 @@ static void mv_xor_v2_tasklet(unsigned long data)
 	/* get the pending descriptors parameters */
 	num_of_pending = mv_xor_v2_get_pending_params(xor_dev, &pending_ptr);
 
-	/* next HW descriptor */
-	next_pending_hw_desc = xor_dev->hw_desq_virt + pending_ptr;
-
 	/* loop over free descriptors */
 	for (i = 0; i < num_of_pending; i++) {
-
-		if (pending_ptr > MV_XOR_V2_DESC_NUM)
-			pending_ptr = 0;
-
-		if (next_pending_sw_desc != NULL)
-			next_pending_hw_desc++;
+		struct mv_xor_v2_descriptor *next_pending_hw_desc =
+			xor_dev->hw_desq_virt + pending_ptr;
 
 		/* get the SW descriptor related to the HW descriptor */
 		next_pending_sw_desc =
@@ -614,6 +606,8 @@ static void mv_xor_v2_tasklet(unsigned long data)
 
 		/* increment the next descriptor */
 		pending_ptr++;
+		if (pending_ptr >= MV_XOR_V2_DESC_NUM)
+			pending_ptr = 0;
 	}
 
 	if (num_of_pending != 0) {
-- 
2.7.4

[PATCH 03/10] dma: mv_xor_v2: do not use descriptors not acked by async_tx

[Thomas Petazzoni]

Descriptors that have not been acknowledged by the async_tx layer
should not be re-used, so this commit adjusts the implementation of
mv_xor_v2_prep_sw_desc() to skip descriptors for which
async_tx_test_ack() is false.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index bdfb36e..cb60e7c 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -344,6 +344,7 @@ static struct mv_xor_v2_sw_desc	*
 mv_xor_v2_prep_sw_desc(struct mv_xor_v2_device *xor_dev)
 {
 	struct mv_xor_v2_sw_desc *sw_desc;
+	bool found = false;
 
 	/* Lock the channel */
 	spin_lock_bh(&xor_dev->lock);
@@ -355,19 +356,23 @@ mv_xor_v2_prep_sw_desc(struct mv_xor_v2_device *xor_dev)
 		return NULL;
 	}
 
-	/* get a free SW descriptor from the SW DESQ */
-	sw_desc = list_first_entry(&xor_dev->free_sw_desc,
-				   struct mv_xor_v2_sw_desc, free_list);
+	list_for_each_entry(sw_desc, &xor_dev->free_sw_desc, free_list) {
+		if (async_tx_test_ack(&sw_desc->async_tx)) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		spin_unlock_bh(&xor_dev->lock);
+		return NULL;
+	}
+
 	list_del(&sw_desc->free_list);
 
 	/* Release the channel */
 	spin_unlock_bh(&xor_dev->lock);
 
-	/* set the async tx descriptor */
-	dma_async_tx_descriptor_init(&sw_desc->async_tx, &xor_dev->dmachan);
-	sw_desc->async_tx.tx_submit = mv_xor_v2_tx_submit;
-	async_tx_ack(&sw_desc->async_tx);
-
 	return sw_desc;
 }
 
@@ -785,8 +790,15 @@ static int mv_xor_v2_probe(struct platform_device *pdev)
 
 	/* add all SW descriptors to the free list */
 	for (i = 0; i < MV_XOR_V2_DESC_NUM; i++) {
-		xor_dev->sw_desq[i].idx = i;
-		list_add(&xor_dev->sw_desq[i].free_list,
+		struct mv_xor_v2_sw_desc *sw_desc =
+			xor_dev->sw_desq + i;
+		sw_desc->idx = i;
+		dma_async_tx_descriptor_init(&sw_desc->async_tx,
+					     &xor_dev->dmachan);
+		sw_desc->async_tx.tx_submit = mv_xor_v2_tx_submit;
+		async_tx_ack(&sw_desc->async_tx);
+
+		list_add(&sw_desc->free_list,
 			 &xor_dev->free_sw_desc);
 	}
 
-- 
2.7.4

[PATCH 03/10] dma: mv_xor_v2: do not use descriptors not acked by async_tx

[Thomas Petazzoni]

Descriptors that have not been acknowledged by the async_tx layer
should not be re-used, so this commit adjusts the implementation of
mv_xor_v2_prep_sw_desc() to skip descriptors for which
async_tx_test_ack() is false.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 32 ++++++++++++++++++++++----------
 1 file changed, 22 insertions(+), 10 deletions(-)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index bdfb36e..cb60e7c 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -344,6 +344,7 @@ static struct mv_xor_v2_sw_desc	*
 mv_xor_v2_prep_sw_desc(struct mv_xor_v2_device *xor_dev)
 {
 	struct mv_xor_v2_sw_desc *sw_desc;
+	bool found = false;
 
 	/* Lock the channel */
 	spin_lock_bh(&xor_dev->lock);
@@ -355,19 +356,23 @@ mv_xor_v2_prep_sw_desc(struct mv_xor_v2_device *xor_dev)
 		return NULL;
 	}
 
-	/* get a free SW descriptor from the SW DESQ */
-	sw_desc = list_first_entry(&xor_dev->free_sw_desc,
-				   struct mv_xor_v2_sw_desc, free_list);
+	list_for_each_entry(sw_desc, &xor_dev->free_sw_desc, free_list) {
+		if (async_tx_test_ack(&sw_desc->async_tx)) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found) {
+		spin_unlock_bh(&xor_dev->lock);
+		return NULL;
+	}
+
 	list_del(&sw_desc->free_list);
 
 	/* Release the channel */
 	spin_unlock_bh(&xor_dev->lock);
 
-	/* set the async tx descriptor */
-	dma_async_tx_descriptor_init(&sw_desc->async_tx, &xor_dev->dmachan);
-	sw_desc->async_tx.tx_submit = mv_xor_v2_tx_submit;
-	async_tx_ack(&sw_desc->async_tx);
-
 	return sw_desc;
 }
 
@@ -785,8 +790,15 @@ static int mv_xor_v2_probe(struct platform_device *pdev)
 
 	/* add all SW descriptors to the free list */
 	for (i = 0; i < MV_XOR_V2_DESC_NUM; i++) {
-		xor_dev->sw_desq[i].idx = i;
-		list_add(&xor_dev->sw_desq[i].free_list,
+		struct mv_xor_v2_sw_desc *sw_desc =
+			xor_dev->sw_desq + i;
+		sw_desc->idx = i;
+		dma_async_tx_descriptor_init(&sw_desc->async_tx,
+					     &xor_dev->dmachan);
+		sw_desc->async_tx.tx_submit = mv_xor_v2_tx_submit;
+		async_tx_ack(&sw_desc->async_tx);
+
+		list_add(&sw_desc->free_list,
 			 &xor_dev->free_sw_desc);
 	}
 
-- 
2.7.4

[PATCH 04/10] dma: mv_xor_v2: enable XOR engine after its configuration

[Thomas Petazzoni]

From: Hanna Hawa <hannah@marvell.com>

The engine was enabled prior to its configuration, which isn't
correct. This patch relocates the activation of the XOR engine, to be
after the configuration of the XOR engine.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Hanna Hawa <hannah@marvell.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index cb60e7c..211b8c0 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -653,9 +653,6 @@ static int mv_xor_v2_descq_init(struct mv_xor_v2_device *xor_dev)
 	writel((xor_dev->hw_desq & 0xFFFF00000000) >> 32,
 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_BAHR_OFF);
 
-	/* enable the DMA engine */
-	writel(0, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
-
 	/*
 	 * This is a temporary solution, until we activate the
 	 * SMMU. Set the attributes for reading & writing data buffers
@@ -699,6 +696,9 @@ static int mv_xor_v2_descq_init(struct mv_xor_v2_device *xor_dev)
 	reg |= MV_XOR_V2_GLOB_PAUSE_AXI_TIME_DIS_VAL;
 	writel(reg, xor_dev->glob_base + MV_XOR_V2_GLOB_PAUSE);
 
+	/* enable the DMA engine */
+	writel(0, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
+
 	return 0;
 }
 
-- 
2.7.4

[PATCH 04/10] dma: mv_xor_v2: enable XOR engine after its configuration

[Thomas Petazzoni]

From: Hanna Hawa <hannah@marvell.com>

The engine was enabled prior to its configuration, which isn't
correct. This patch relocates the activation of the XOR engine, to be
after the configuration of the XOR engine.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Hanna Hawa <hannah@marvell.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index cb60e7c..211b8c0 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -653,9 +653,6 @@ static int mv_xor_v2_descq_init(struct mv_xor_v2_device *xor_dev)
 	writel((xor_dev->hw_desq & 0xFFFF00000000) >> 32,
 	       xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_BAHR_OFF);
 
-	/* enable the DMA engine */
-	writel(0, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
-
 	/*
 	 * This is a temporary solution, until we activate the
 	 * SMMU. Set the attributes for reading & writing data buffers
@@ -699,6 +696,9 @@ static int mv_xor_v2_descq_init(struct mv_xor_v2_device *xor_dev)
 	reg |= MV_XOR_V2_GLOB_PAUSE_AXI_TIME_DIS_VAL;
 	writel(reg, xor_dev->glob_base + MV_XOR_V2_GLOB_PAUSE);
 
+	/* enable the DMA engine */
+	writel(0, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
+
 	return 0;
 }
 
-- 
2.7.4

[PATCH 05/10] dma: mv_xor_v2: fix tx_submit() implementation

[Thomas Petazzoni]

The mv_xor_v2_tx_submit() gets the next available HW descriptor by
calling mv_xor_v2_get_desq_write_ptr(), which reads a HW register
telling the next available HW descriptor. This was working fine when HW
descriptors were issued for processing directly in tx_submit().

However, as part of the review process of the driver, a change was
requested to move the actual kick-off of HW descriptors processing to
->issue_pending(). Due to this, reading the HW register to know the next
available HW descriptor no longer works.

So instead of using this HW register, we implemented a software index
pointing to the next available HW descriptor.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 22 +++++-----------------
 1 file changed, 5 insertions(+), 17 deletions(-)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index 211b8c0..4684ece 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -161,6 +161,7 @@ struct mv_xor_v2_device {
 	struct mv_xor_v2_sw_desc *sw_desq;
 	int desc_size;
 	unsigned int npendings;
+	unsigned int hw_queue_idx;
 };
 
 /**
@@ -214,18 +215,6 @@ static void mv_xor_v2_set_data_buffers(struct mv_xor_v2_device *xor_dev,
 }
 
 /*
- * Return the next available index in the DESQ.
- */
-static int mv_xor_v2_get_desq_write_ptr(struct mv_xor_v2_device *xor_dev)
-{
-	/* read the index for the next available descriptor in the DESQ */
-	u32 reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ALLOC_OFF);
-
-	return ((reg >> MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_SHIFT)
-		& MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_MASK);
-}
-
-/*
  * notify the engine of new descriptors, and update the available index.
  */
 static void mv_xor_v2_add_desc_to_desq(struct mv_xor_v2_device *xor_dev,
@@ -306,7 +295,6 @@ static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
 static dma_cookie_t
 mv_xor_v2_tx_submit(struct dma_async_tx_descriptor *tx)
 {
-	int desq_ptr;
 	void *dest_hw_desc;
 	dma_cookie_t cookie;
 	struct mv_xor_v2_sw_desc *sw_desc =
@@ -322,15 +310,15 @@ mv_xor_v2_tx_submit(struct dma_async_tx_descriptor *tx)
 	spin_lock_bh(&xor_dev->lock);
 	cookie = dma_cookie_assign(tx);
 
-	/* get the next available slot in the DESQ */
-	desq_ptr = mv_xor_v2_get_desq_write_ptr(xor_dev);
-
 	/* copy the HW descriptor from the SW descriptor to the DESQ */
-	dest_hw_desc = xor_dev->hw_desq_virt + desq_ptr;
+	dest_hw_desc = xor_dev->hw_desq_virt + xor_dev->hw_queue_idx;
 
 	memcpy(dest_hw_desc, &sw_desc->hw_desc, xor_dev->desc_size);
 
 	xor_dev->npendings++;
+	xor_dev->hw_queue_idx++;
+	if (xor_dev->hw_queue_idx >= MV_XOR_V2_DESC_NUM)
+		xor_dev->hw_queue_idx = 0;
 
 	spin_unlock_bh(&xor_dev->lock);
 
-- 
2.7.4

[PATCH 05/10] dma: mv_xor_v2: fix tx_submit() implementation

[Thomas Petazzoni]

The mv_xor_v2_tx_submit() gets the next available HW descriptor by
calling mv_xor_v2_get_desq_write_ptr(), which reads a HW register
telling the next available HW descriptor. This was working fine when HW
descriptors were issued for processing directly in tx_submit().

However, as part of the review process of the driver, a change was
requested to move the actual kick-off of HW descriptors processing to
->issue_pending(). Due to this, reading the HW register to know the next
available HW descriptor no longer works.

So instead of using this HW register, we implemented a software index
pointing to the next available HW descriptor.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 22 +++++-----------------
 1 file changed, 5 insertions(+), 17 deletions(-)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index 211b8c0..4684ece 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -161,6 +161,7 @@ struct mv_xor_v2_device {
 	struct mv_xor_v2_sw_desc *sw_desq;
 	int desc_size;
 	unsigned int npendings;
+	unsigned int hw_queue_idx;
 };
 
 /**
@@ -214,18 +215,6 @@ static void mv_xor_v2_set_data_buffers(struct mv_xor_v2_device *xor_dev,
 }
 
 /*
- * Return the next available index in the DESQ.
- */
-static int mv_xor_v2_get_desq_write_ptr(struct mv_xor_v2_device *xor_dev)
-{
-	/* read the index for the next available descriptor in the DESQ */
-	u32 reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_ALLOC_OFF);
-
-	return ((reg >> MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_SHIFT)
-		& MV_XOR_V2_DMA_DESQ_ALLOC_WRPTR_MASK);
-}
-
-/*
  * notify the engine of new descriptors, and update the available index.
  */
 static void mv_xor_v2_add_desc_to_desq(struct mv_xor_v2_device *xor_dev,
@@ -306,7 +295,6 @@ static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
 static dma_cookie_t
 mv_xor_v2_tx_submit(struct dma_async_tx_descriptor *tx)
 {
-	int desq_ptr;
 	void *dest_hw_desc;
 	dma_cookie_t cookie;
 	struct mv_xor_v2_sw_desc *sw_desc =
@@ -322,15 +310,15 @@ mv_xor_v2_tx_submit(struct dma_async_tx_descriptor *tx)
 	spin_lock_bh(&xor_dev->lock);
 	cookie = dma_cookie_assign(tx);
 
-	/* get the next available slot in the DESQ */
-	desq_ptr = mv_xor_v2_get_desq_write_ptr(xor_dev);
-
 	/* copy the HW descriptor from the SW descriptor to the DESQ */
-	dest_hw_desc = xor_dev->hw_desq_virt + desq_ptr;
+	dest_hw_desc = xor_dev->hw_desq_virt + xor_dev->hw_queue_idx;
 
 	memcpy(dest_hw_desc, &sw_desc->hw_desc, xor_dev->desc_size);
 
 	xor_dev->npendings++;
+	xor_dev->hw_queue_idx++;
+	if (xor_dev->hw_queue_idx >= MV_XOR_V2_DESC_NUM)
+		xor_dev->hw_queue_idx = 0;
 
 	spin_unlock_bh(&xor_dev->lock);
 
-- 
2.7.4

[PATCH 06/10] dma: mv_xor_v2: remove interrupt coalescing

[Thomas Petazzoni]

The current implementation of interrupt coalescing doesn't work, because
it doesn't configure the coalescing timer, which is needed to make sure
we get an interrupt at some point.

As a fix for stable, we simply remove the interrupt coalescing
functionality. It will be re-introduced properly in a future commit.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 25 -------------------------
 1 file changed, 25 deletions(-)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index 4684ece..b133fe2 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -246,22 +246,6 @@ static int mv_xor_v2_set_desc_size(struct mv_xor_v2_device *xor_dev)
 	return MV_XOR_V2_EXT_DESC_SIZE;
 }
 
-/*
- * Set the IMSG threshold
- */
-static inline
-void mv_xor_v2_set_imsg_thrd(struct mv_xor_v2_device *xor_dev, int thrd_val)
-{
-	u32 reg;
-
-	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
-
-	reg &= (~MV_XOR_V2_DMA_IMSG_THRD_MASK << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
-	reg |= (thrd_val << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
-
-	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
-}
-
 static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
 {
 	struct mv_xor_v2_device *xor_dev = data;
@@ -277,12 +261,6 @@ static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
 	if (!ndescs)
 		return IRQ_NONE;
 
-	/*
-	 * Update IMSG threshold, to disable new IMSG interrupts until
-	 * end of the tasklet
-	 */
-	mv_xor_v2_set_imsg_thrd(xor_dev, MV_XOR_V2_DESC_NUM);
-
 	/* schedule a tasklet to handle descriptors callbacks */
 	tasklet_schedule(&xor_dev->irq_tasklet);
 
@@ -607,9 +585,6 @@ static void mv_xor_v2_tasklet(unsigned long data)
 		/* free the descriptores */
 		mv_xor_v2_free_desc_from_desq(xor_dev, num_of_pending);
 	}
-
-	/* Update IMSG threshold, to enable new IMSG interrupts */
-	mv_xor_v2_set_imsg_thrd(xor_dev, 0);
 }
 
 /*
-- 
2.7.4

[PATCH 06/10] dma: mv_xor_v2: remove interrupt coalescing

[Thomas Petazzoni]

The current implementation of interrupt coalescing doesn't work, because
it doesn't configure the coalescing timer, which is needed to make sure
we get an interrupt at some point.

As a fix for stable, we simply remove the interrupt coalescing
functionality. It will be re-introduced properly in a future commit.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 25 -------------------------
 1 file changed, 25 deletions(-)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index 4684ece..b133fe2 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -246,22 +246,6 @@ static int mv_xor_v2_set_desc_size(struct mv_xor_v2_device *xor_dev)
 	return MV_XOR_V2_EXT_DESC_SIZE;
 }
 
-/*
- * Set the IMSG threshold
- */
-static inline
-void mv_xor_v2_set_imsg_thrd(struct mv_xor_v2_device *xor_dev, int thrd_val)
-{
-	u32 reg;
-
-	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
-
-	reg &= (~MV_XOR_V2_DMA_IMSG_THRD_MASK << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
-	reg |= (thrd_val << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
-
-	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
-}
-
 static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
 {
 	struct mv_xor_v2_device *xor_dev = data;
@@ -277,12 +261,6 @@ static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
 	if (!ndescs)
 		return IRQ_NONE;
 
-	/*
-	 * Update IMSG threshold, to disable new IMSG interrupts until
-	 * end of the tasklet
-	 */
-	mv_xor_v2_set_imsg_thrd(xor_dev, MV_XOR_V2_DESC_NUM);
-
 	/* schedule a tasklet to handle descriptors callbacks */
 	tasklet_schedule(&xor_dev->irq_tasklet);
 
@@ -607,9 +585,6 @@ static void mv_xor_v2_tasklet(unsigned long data)
 		/* free the descriptores */
 		mv_xor_v2_free_desc_from_desq(xor_dev, num_of_pending);
 	}
-
-	/* Update IMSG threshold, to enable new IMSG interrupts */
-	mv_xor_v2_set_imsg_thrd(xor_dev, 0);
 }
 
 /*
-- 
2.7.4

[PATCH 07/10] dma: mv_xor_v2: set DMA mask to 40 bits

[Thomas Petazzoni]

The XORv2 engine on Armada 7K/8K can only access the first 40 bits of
the physical address space, so the DMA mask must be set accordingly.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index b133fe2..f3e211f 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -693,6 +693,10 @@ static int mv_xor_v2_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, xor_dev);
 
+	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
+	if (ret)
+		return ret;
+
 	xor_dev->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(xor_dev->clk) && PTR_ERR(xor_dev->clk) == -EPROBE_DEFER)
 		return -EPROBE_DEFER;
-- 
2.7.4

[PATCH 07/10] dma: mv_xor_v2: set DMA mask to 40 bits

[Thomas Petazzoni]

The XORv2 engine on Armada 7K/8K can only access the first 40 bits of
the physical address space, so the DMA mask must be set accordingly.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index b133fe2..f3e211f 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -693,6 +693,10 @@ static int mv_xor_v2_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, xor_dev);
 
+	ret = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(40));
+	if (ret)
+		return ret;
+
 	xor_dev->clk = devm_clk_get(&pdev->dev, NULL);
 	if (IS_ERR(xor_dev->clk) && PTR_ERR(xor_dev->clk) == -EPROBE_DEFER)
 		return -EPROBE_DEFER;
-- 
2.7.4

[PATCH 08/10] dma: mv_xor_v2: implement proper interrupt coalescing

[Thomas Petazzoni]

From: Hanna Hawa <hannah@marvell.com>

Until now, the driver was not using interrupt coalescing: one interrupt
was generated for each descriptor processed by the XOR engine. This
commit changes that by using the interrupt coalescing features of the
hardware, by setting both a number of descriptors processed before an
interrupt is generated and a timeout before an interrupt is generated.

Signed-off-by: Hanna Hawa <hannah@marvell.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index f3e211f..5292ff2 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -42,6 +42,7 @@
 #define MV_XOR_V2_DMA_IMSG_THRD_OFF			0x018
 #define   MV_XOR_V2_DMA_IMSG_THRD_MASK			0x7FFF
 #define   MV_XOR_V2_DMA_IMSG_THRD_SHIFT			0x0
+#define   MV_XOR_V2_DMA_IMSG_TIMER_EN			BIT(18)
 #define MV_XOR_V2_DMA_DESQ_AWATTR_OFF			0x01C
   /* Same flags as MV_XOR_V2_DMA_DESQ_ARATTR_OFF */
 #define MV_XOR_V2_DMA_DESQ_ALLOC_OFF			0x04C
@@ -55,6 +56,9 @@
 #define MV_XOR_V2_DMA_DESQ_STOP_OFF			0x800
 #define MV_XOR_V2_DMA_DESQ_DEALLOC_OFF			0x804
 #define MV_XOR_V2_DMA_DESQ_ADD_OFF			0x808
+#define MV_XOR_V2_DMA_IMSG_TMOT				0x810
+#define   MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK		0x1FFF
+#define   MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT		0
 
 /* XOR Global registers */
 #define MV_XOR_V2_GLOB_BW_CTRL				0x4
@@ -90,6 +94,13 @@
  */
 #define MV_XOR_V2_DESC_NUM				1024
 
+/*
+ * Threshold values for descriptors and timeout, determined by
+ * experimentation as giving a good level of performance.
+ */
+#define MV_XOR_V2_DONE_IMSG_THRD  0x14
+#define MV_XOR_V2_TIMER_THRD      0xB0
+
 /**
  * struct mv_xor_v2_descriptor - DMA HW descriptor
  * @desc_id: used by S/W and is not affected by H/W.
@@ -246,6 +257,29 @@ static int mv_xor_v2_set_desc_size(struct mv_xor_v2_device *xor_dev)
 	return MV_XOR_V2_EXT_DESC_SIZE;
 }
 
+/*
+ * Set the IMSG threshold
+ */
+static inline
+void mv_xor_v2_enable_imsg_thrd(struct mv_xor_v2_device *xor_dev)
+{
+	u32 reg;
+
+	/* Configure threshold of number of descriptors, and enable timer */
+	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
+	reg &= (~MV_XOR_V2_DMA_IMSG_THRD_MASK << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
+	reg |= (MV_XOR_V2_DONE_IMSG_THRD << MV_XOR_V2_DMA_IMSG_THRD_SHIFT);
+	reg |= MV_XOR_V2_DMA_IMSG_TIMER_EN;
+	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_THRD_OFF);
+
+	/* Configure Timer Threshold */
+	reg = readl(xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_TMOT);
+	reg &= (~MV_XOR_V2_DMA_IMSG_TIMER_THRD_MASK <<
+		MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT);
+	reg |= (MV_XOR_V2_TIMER_THRD << MV_XOR_V2_DMA_IMSG_TIMER_THRD_SHIFT);
+	writel(reg, xor_dev->dma_base + MV_XOR_V2_DMA_IMSG_TMOT);
+}
+
 static irqreturn_t mv_xor_v2_interrupt_handler(int irq, void *data)
 {
 	struct mv_xor_v2_device *xor_dev = data;
@@ -795,6 +829,8 @@ static int mv_xor_v2_probe(struct platform_device *pdev)
 	list_add_tail(&xor_dev->dmachan.device_node,
 		      &dma_dev->channels);
 
+	mv_xor_v2_enable_imsg_thrd(xor_dev);
+
 	mv_xor_v2_descq_init(xor_dev);
 
 	ret = dma_async_device_register(dma_dev);
-- 
2.7.4

[PATCH 09/10] dma: mv_xor_v2: remove unnecessary write to DESQ_STOP register

[Thomas Petazzoni]

From: Hanna Hawa <hannah@marvell.com>

Remove unnecessary write to DESQ_STOP register, this register is used to
enable or disable the XOR engine, and not to issue all pending
descriptors in the queue. mv_xor_v2 driver already writes to this
register and enable XOR engine in the mv_xor_v2_descq_init() function,
called during initialization.

Signed-off-by: Hanna Hawa <hannah@marvell.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index 5292ff2..f386b88 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -535,9 +535,6 @@ static void mv_xor_v2_issue_pending(struct dma_chan *chan)
 	mv_xor_v2_add_desc_to_desq(xor_dev, xor_dev->npendings);
 	xor_dev->npendings = 0;
 
-	/* Activate the channel */
-	writel(0, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
-
 	spin_unlock_bh(&xor_dev->lock);
 }
 
-- 
2.7.4

[PATCH 10/10] dma: mv_xor_v2: add support for suspend/resume

[Thomas Petazzoni]

From: Hanna Hawa <hannah@marvell.com>

This commit adds the support for suspend/resume in the mv_xor_v2
driver. The suspend suspend function disables the XOR engine after the
DMA stack has handled all pending descriptors in the queue. The resume
function re-configures the XOR engine and re-enables the engine.

Signed-off-by: Hanna Hawa <hannah@marvell.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
---
 drivers/dma/mv_xor_v2.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

diff --git a/drivers/dma/mv_xor_v2.c b/drivers/dma/mv_xor_v2.c
index f386b88..f652a0e 100644
--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -696,6 +696,27 @@ static int mv_xor_v2_descq_init(struct mv_xor_v2_device *xor_dev)
 	return 0;
 }
 
+static int mv_xor_v2_suspend(struct platform_device *dev, pm_message_t state)
+{
+	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(dev);
+
+	/* Set this bit to disable to stop the XOR unit. */
+	writel(0x1, xor_dev->dma_base + MV_XOR_V2_DMA_DESQ_STOP_OFF);
+
+	return 0;
+}
+
+static int mv_xor_v2_resume(struct platform_device *dev)
+{
+	struct mv_xor_v2_device *xor_dev = platform_get_drvdata(dev);
+
+	mv_xor_v2_set_desc_size(xor_dev);
+	mv_xor_v2_enable_imsg_thrd(xor_dev);
+	mv_xor_v2_descq_init(xor_dev);
+
+	return 0;
+}
+
 static int mv_xor_v2_probe(struct platform_device *pdev)
 {
 	struct mv_xor_v2_device *xor_dev;
@@ -877,6 +898,8 @@ MODULE_DEVICE_TABLE(of, mv_xor_v2_dt_ids);
 
 static struct platform_driver mv_xor_v2_driver = {
 	.probe		= mv_xor_v2_probe,
+	.suspend	= mv_xor_v2_suspend,
+	.resume		= mv_xor_v2_resume,
 	.remove		= mv_xor_v2_remove,
 	.driver		= {
 		.name	= "mv_xor_v2",
-- 
2.7.4

[PATCH 00/10] dma: mv_xor_v2: fixes and improvements

[Vinod Koul]

On Fri, May 05, 2017 at 11:57:43AM +0200, Thomas Petazzoni wrote:
> Hello,
> 
> This series brings a number of fixes (first 7 patches) and
> improvements (last 3 patches) to the driver used for the Marvell XORv2
> engine used in Marvell Armada 7K/8K.

And 7 going to stable :(

Anyway I have applied all, *after* fixing the subsystem name for all :(

-- 
~Vinod

[PATCH 00/10] dma: mv_xor_v2: fixes and improvements

[Thomas Petazzoni]

Hello,

On Sun, 14 May 2017 18:28:09 +0530, Vinod Koul wrote:

> > This series brings a number of fixes (first 7 patches) and
> > improvements (last 3 patches) to the driver used for the Marvell XORv2
> > engine used in Marvell Armada 7K/8K.  
> 
> And 7 going to stable :(

Yes, but hopefully we should now be a good shape.

> Anyway I have applied all, *after* fixing the subsystem name for all :(

Sorry for getting the subsystem name wrong, I would have been happy to
fix that myself and resend to reduce your workload. But anyway, thanks
for fixing those and applying the patches!

Thomas
-- 
Thomas Petazzoni, CTO, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com