dmaengine: remove DMA_SG as it is dead code in kernel

There are no in kernel consumers for DMA_SG op. Removing operation,
dead code, and test code in dmatest.

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Gary Hook <gary.hook@amd.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Kedareswara rao Appana <appana.durga.rao@xilinx.com>
Cc: Li Yang <leoyang.li@nxp.com>
Cc: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

9 files changed, 5 insertions, 737 deletions

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 1baf3404a365..fbab271b3bf9 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -1203,138 +1203,6 @@ err:
 }
 
 /**
- * atc_prep_dma_sg - prepare memory to memory scather-gather operation
- * @chan: the channel to prepare operation on
- * @dst_sg: destination scatterlist
- * @dst_nents: number of destination scatterlist entries
- * @src_sg: source scatterlist
- * @src_nents: number of source scatterlist entries
- * @flags: tx descriptor status flags
- */
-static struct dma_async_tx_descriptor *
-atc_prep_dma_sg(struct dma_chan *chan,
-		struct scatterlist *dst_sg, unsigned int dst_nents,
-		struct scatterlist *src_sg, unsigned int src_nents,
-		unsigned long flags)
-{
-	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
-	struct at_desc		*desc = NULL;
-	struct at_desc		*first = NULL;
-	struct at_desc		*prev = NULL;
-	unsigned int		src_width;
-	unsigned int		dst_width;
-	size_t			xfer_count;
-	u32			ctrla;
-	u32			ctrlb;
-	size_t			dst_len = 0, src_len = 0;
-	dma_addr_t		dst = 0, src = 0;
-	size_t			len = 0, total_len = 0;
-
-	if (unlikely(dst_nents == 0 || src_nents == 0))
-		return NULL;
-
-	if (unlikely(dst_sg == NULL || src_sg == NULL))
-		return NULL;
-
-	ctrlb =   ATC_DEFAULT_CTRLB | ATC_IEN
-		| ATC_SRC_ADDR_MODE_INCR
-		| ATC_DST_ADDR_MODE_INCR
-		| ATC_FC_MEM2MEM;
-
-	/*
-	 * loop until there is either no more source or no more destination
-	 * scatterlist entry
-	 */
-	while (true) {
-
-		/* prepare the next transfer */
-		if (dst_len == 0) {
-
-			/* no more destination scatterlist entries */
-			if (!dst_sg || !dst_nents)
-				break;
-
-			dst = sg_dma_address(dst_sg);
-			dst_len = sg_dma_len(dst_sg);
-
-			dst_sg = sg_next(dst_sg);
-			dst_nents--;
-		}
-
-		if (src_len == 0) {
-
-			/* no more source scatterlist entries */
-			if (!src_sg || !src_nents)
-				break;
-
-			src = sg_dma_address(src_sg);
-			src_len = sg_dma_len(src_sg);
-
-			src_sg = sg_next(src_sg);
-			src_nents--;
-		}
-
-		len = min_t(size_t, src_len, dst_len);
-		if (len == 0)
-			continue;
-
-		/* take care for the alignment */
-		src_width = dst_width = atc_get_xfer_width(src, dst, len);
-
-		ctrla = ATC_SRC_WIDTH(src_width) |
-			ATC_DST_WIDTH(dst_width);
-
-		/*
-		 * The number of transfers to set up refer to the source width
-		 * that depends on the alignment.
-		 */
-		xfer_count = len >> src_width;
-		if (xfer_count > ATC_BTSIZE_MAX) {
-			xfer_count = ATC_BTSIZE_MAX;
-			len = ATC_BTSIZE_MAX << src_width;
-		}
-
-		/* create the transfer */
-		desc = atc_desc_get(atchan);
-		if (!desc)
-			goto err_desc_get;
-
-		desc->lli.saddr = src;
-		desc->lli.daddr = dst;
-		desc->lli.ctrla = ctrla | xfer_count;
-		desc->lli.ctrlb = ctrlb;
-
-		desc->txd.cookie = 0;
-		desc->len = len;
-
-		atc_desc_chain(&first, &prev, desc);
-
-		/* update the lengths and addresses for the next loop cycle */
-		dst_len -= len;
-		src_len -= len;
-		dst += len;
-		src += len;
-
-		total_len += len;
-	}
-
-	/* First descriptor of the chain embedds additional information */
-	first->txd.cookie = -EBUSY;
-	first->total_len = total_len;
-
-	/* set end-of-link to the last link descriptor of list*/
-	set_desc_eol(desc);
-
-	first->txd.flags = flags; /* client is in control of this ack */
-
-	return &first->txd;
-
-err_desc_get:
-	atc_desc_put(atchan, first);
-	return NULL;
-}
-
-/**
  * atc_dma_cyclic_check_values
  * Check for too big/unaligned periods and unaligned DMA buffer
  */
@@ -1933,14 +1801,12 @@ static int __init at_dma_probe(struct platform_device *pdev)
 
 	/* setup platform data for each SoC */
 	dma_cap_set(DMA_MEMCPY, at91sam9rl_config.cap_mask);
-	dma_cap_set(DMA_SG, at91sam9rl_config.cap_mask);
 	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);
 
 	/* get DMA parameters from controller type */
 	plat_dat = at_dma_get_driver_data(pdev);
@@ -2078,16 +1944,12 @@ static int __init at_dma_probe(struct platform_device *pdev)
 		atdma->dma_common.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
 	}
 
-	if (dma_has_cap(DMA_SG, atdma->dma_common.cap_mask))
-		atdma->dma_common.device_prep_dma_sg = atc_prep_dma_sg;
-
 	dma_writel(atdma, EN, AT_DMA_ENABLE);
 
-	dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s%s%s), %d channels\n",
+	dev_info(&pdev->dev, "Atmel AHB DMA Controller ( %s%s%s), %d channels\n",
 	  dma_has_cap(DMA_MEMCPY, atdma->dma_common.cap_mask) ? "cpy " : "",
 	  dma_has_cap(DMA_MEMSET, atdma->dma_common.cap_mask) ? "set " : "",
 	  dma_has_cap(DMA_SLAVE, atdma->dma_common.cap_mask)  ? "slave " : "",
-	  dma_has_cap(DMA_SG, atdma->dma_common.cap_mask)  ? "sg-cpy " : "",
 	  plat_dat->nr_channels);
 
 	dma_async_device_register(&atdma->dma_common);
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index d9118ec23025..428b1414263a 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -937,8 +937,6 @@ int dma_async_device_register(struct dma_device *device)
 		!device->device_prep_dma_memset);
 	BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
 		!device->device_prep_dma_interrupt);
-	BUG_ON(dma_has_cap(DMA_SG, device->cap_mask) &&
-		!device->device_prep_dma_sg);
 	BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) &&
 		!device->device_prep_dma_cyclic);
 	BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) &&
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index 35cb83b39192..34ff53290b03 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -52,15 +52,10 @@ module_param(iterations, uint, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(iterations,
 		"Iterations before stopping test (default: infinite)");
 
-static unsigned int sg_buffers = 1;
-module_param(sg_buffers, uint, S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(sg_buffers,
-		"Number of scatter gather buffers (default: 1)");
-
 static unsigned int dmatest;
 module_param(dmatest, uint, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(dmatest,
-		"dmatest 0-memcpy 1-slave_sg 2-memset (default: 0)");
+		"dmatest 0-memcpy 1-memset (default: 0)");
 
 static unsigned int xor_sources = 3;
 module_param(xor_sources, uint, S_IRUGO | S_IWUSR);
@@ -471,9 +466,6 @@ static int dmatest_func(void *data)
 		align = dev->fill_align;
 		src_cnt = dst_cnt = 1;
 		is_memset = true;
-	} else if (thread->type == DMA_SG) {
-		align = dev->copy_align;
-		src_cnt = dst_cnt = sg_buffers;
 	} else if (thread->type == DMA_XOR) {
 		/* force odd to ensure dst = src */
 		src_cnt = min_odd(params->xor_sources | 1, dev->max_xor);
@@ -553,8 +545,6 @@ static int dmatest_func(void *data)
 		dma_addr_t srcs[src_cnt];
 		dma_addr_t *dsts;
 		unsigned int src_off, dst_off, len;
-		struct scatterlist tx_sg[src_cnt];
-		struct scatterlist rx_sg[src_cnt];
 
 		total_tests++;
 
@@ -650,15 +640,6 @@ static int dmatest_func(void *data)
 			um->bidi_cnt++;
 		}
 
-		sg_init_table(tx_sg, src_cnt);
-		sg_init_table(rx_sg, src_cnt);
-		for (i = 0; i < src_cnt; i++) {
-			sg_dma_address(&rx_sg[i]) = srcs[i];
-			sg_dma_address(&tx_sg[i]) = dsts[i] + dst_off;
-			sg_dma_len(&tx_sg[i]) = len;
-			sg_dma_len(&rx_sg[i]) = len;
-		}
-
 		if (thread->type == DMA_MEMCPY)
 			tx = dev->device_prep_dma_memcpy(chan,
 							 dsts[0] + dst_off,
@@ -668,9 +649,6 @@ static int dmatest_func(void *data)
 						dsts[0] + dst_off,
 						*(thread->srcs[0] + src_off),
 						len, flags);
-		else if (thread->type == DMA_SG)
-			tx = dev->device_prep_dma_sg(chan, tx_sg, src_cnt,
-						     rx_sg, src_cnt, flags);
 		else if (thread->type == DMA_XOR)
 			tx = dev->device_prep_dma_xor(chan,
 						      dsts[0] + dst_off,
@@ -853,8 +831,6 @@ static int dmatest_add_threads(struct dmatest_info *info,
 		op = "copy";
 	else if (type == DMA_MEMSET)
 		op = "set";
-	else if (type == DMA_SG)
-		op = "sg";
 	else if (type == DMA_XOR)
 		op = "xor";
 	else if (type == DMA_PQ)
@@ -916,15 +892,8 @@ static int dmatest_add_channel(struct dmatest_info *info,
 	}
 
 	if (dma_has_cap(DMA_MEMSET, dma_dev->cap_mask)) {
-		if (dmatest == 2) {
-			cnt = dmatest_add_threads(info, dtc, DMA_MEMSET);
-			thread_count += cnt > 0 ? cnt : 0;
-		}
-	}
-
-	if (dma_has_cap(DMA_SG, dma_dev->cap_mask)) {
 		if (dmatest == 1) {
-			cnt = dmatest_add_threads(info, dtc, DMA_SG);
+			cnt = dmatest_add_threads(info, dtc, DMA_MEMSET);
 			thread_count += cnt > 0 ? cnt : 0;
 		}
 	}
@@ -1002,7 +971,6 @@ static void run_threaded_test(struct dmatest_info *info)
 	request_channels(info, DMA_MEMCPY);
 	request_channels(info, DMA_MEMSET);
 	request_channels(info, DMA_XOR);
-	request_channels(info, DMA_SG);
 	request_channels(info, DMA_PQ);
 }
 
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index 3b8b752ede2d..3eaece888e75 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -825,122 +825,6 @@ fail:
 	return NULL;
 }
 
-static struct dma_async_tx_descriptor *fsl_dma_prep_sg(struct dma_chan *dchan,
-	struct scatterlist *dst_sg, unsigned int dst_nents,
-	struct scatterlist *src_sg, unsigned int src_nents,
-	unsigned long flags)
-{
-	struct fsl_desc_sw *first = NULL, *prev = NULL, *new = NULL;
-	struct fsldma_chan *chan = to_fsl_chan(dchan);
-	size_t dst_avail, src_avail;
-	dma_addr_t dst, src;
-	size_t len;
-
-	/* basic sanity checks */
-	if (dst_nents == 0 || src_nents == 0)
-		return NULL;
-
-	if (dst_sg == NULL || src_sg == NULL)
-		return NULL;
-
-	/*
-	 * TODO: should we check that both scatterlists have the same
-	 * TODO: number of bytes in total? Is that really an error?
-	 */
-
-	/* get prepared for the loop */
-	dst_avail = sg_dma_len(dst_sg);
-	src_avail = sg_dma_len(src_sg);
-
-	/* run until we are out of scatterlist entries */
-	while (true) {
-
-		/* create the largest transaction possible */
-		len = min_t(size_t, src_avail, dst_avail);
-		len = min_t(size_t, len, FSL_DMA_BCR_MAX_CNT);
-		if (len == 0)
-			goto fetch;
-
-		dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
-		src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
-
-		/* allocate and populate the descriptor */
-		new = fsl_dma_alloc_descriptor(chan);
-		if (!new) {
-			chan_err(chan, "%s\n", msg_ld_oom);
-			goto fail;
-		}
-
-		set_desc_cnt(chan, &new->hw, len);
-		set_desc_src(chan, &new->hw, src);
-		set_desc_dst(chan, &new->hw, dst);
-
-		if (!first)
-			first = new;
-		else
-			set_desc_next(chan, &prev->hw, new->async_tx.phys);
-
-		new->async_tx.cookie = 0;
-		async_tx_ack(&new->async_tx);
-		prev = new;
-
-		/* Insert the link descriptor to the LD ring */
-		list_add_tail(&new->node, &first->tx_list);
-
-		/* update metadata */
-		dst_avail -= len;
-		src_avail -= len;
-
-fetch:
-		/* fetch the next dst scatterlist entry */
-		if (dst_avail == 0) {
-
-			/* no more entries: we're done */
-			if (dst_nents == 0)
-				break;
-
-			/* fetch the next entry: if there are no more: done */
-			dst_sg = sg_next(dst_sg);
-			if (dst_sg == NULL)
-				break;
-
-			dst_nents--;
-			dst_avail = sg_dma_len(dst_sg);
-		}
-
-		/* fetch the next src scatterlist entry */
-		if (src_avail == 0) {
-
-			/* no more entries: we're done */
-			if (src_nents == 0)
-				break;
-
-			/* fetch the next entry: if there are no more: done */
-			src_sg = sg_next(src_sg);
-			if (src_sg == NULL)
-				break;
-
-			src_nents--;
-			src_avail = sg_dma_len(src_sg);
-		}
-	}
-
-	new->async_tx.flags = flags; /* client is in control of this ack */
-	new->async_tx.cookie = -EBUSY;
-
-	/* Set End-of-link to the last link descriptor of new list */
-	set_ld_eol(chan, new);
-
-	return &first->async_tx;
-
-fail:
-	if (!first)
-		return NULL;
-
-	fsldma_free_desc_list_reverse(chan, &first->tx_list);
-	return NULL;
-}
-
 static int fsl_dma_device_terminate_all(struct dma_chan *dchan)
 {
 	struct fsldma_chan *chan;
@@ -1357,12 +1241,10 @@ static int fsldma_of_probe(struct platform_device *op)
 	fdev->irq = irq_of_parse_and_map(op->dev.of_node, 0);
 
 	dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
-	dma_cap_set(DMA_SG, fdev->common.cap_mask);
 	dma_cap_set(DMA_SLAVE, fdev->common.cap_mask);
 	fdev->common.device_alloc_chan_resources = fsl_dma_alloc_chan_resources;
 	fdev->common.device_free_chan_resources = fsl_dma_free_chan_resources;
 	fdev->common.device_prep_dma_memcpy = fsl_dma_prep_memcpy;
-	fdev->common.device_prep_dma_sg = fsl_dma_prep_sg;
 	fdev->common.device_tx_status = fsl_tx_status;
 	fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
 	fdev->common.device_config = fsl_dma_device_config;
diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index 25bc5b103aa2..1993889003fd 100644
--- a/drivers/dma/mv_xor.c
+++ b/drivers/dma/mv_xor.c
@@ -68,36 +68,6 @@ static void mv_desc_init(struct mv_xor_desc_slot *desc,
 	hw_desc->byte_count = byte_count;
 }
 
-/* Populate the descriptor */
-static void mv_xor_config_sg_ll_desc(struct mv_xor_desc_slot *desc,
-				     dma_addr_t dma_src, dma_addr_t dma_dst,
-				     u32 len, struct mv_xor_desc_slot *prev)
-{
-	struct mv_xor_desc *hw_desc = desc->hw_desc;
-
-	hw_desc->status = XOR_DESC_DMA_OWNED;
-	hw_desc->phy_next_desc = 0;
-	/* Configure for XOR with only one src address -> MEMCPY */
-	hw_desc->desc_command = XOR_DESC_OPERATION_XOR | (0x1 << 0);
-	hw_desc->phy_dest_addr = dma_dst;
-	hw_desc->phy_src_addr[0] = dma_src;
-	hw_desc->byte_count = len;
-
-	if (prev) {
-		struct mv_xor_desc *hw_prev = prev->hw_desc;
-
-		hw_prev->phy_next_desc = desc->async_tx.phys;
-	}
-}
-
-static void mv_xor_desc_config_eod(struct mv_xor_desc_slot *desc)
-{
-	struct mv_xor_desc *hw_desc = desc->hw_desc;
-
-	/* Enable end-of-descriptor interrupt */
-	hw_desc->desc_command |= XOR_DESC_EOD_INT_EN;
-}
-
 static void mv_desc_set_mode(struct mv_xor_desc_slot *desc)
 {
 	struct mv_xor_desc *hw_desc = desc->hw_desc;
@@ -662,132 +632,6 @@ mv_xor_prep_dma_interrupt(struct dma_chan *chan, unsigned long flags)
 	return mv_xor_prep_dma_xor(chan, dest, &src, 1, len, flags);
 }
 
-/**
- * mv_xor_prep_dma_sg - prepare descriptors for a memory sg transaction
- * @chan: DMA channel
- * @dst_sg: Destination scatter list
- * @dst_sg_len: Number of entries in destination scatter list
- * @src_sg: Source scatter list
- * @src_sg_len: Number of entries in source scatter list
- * @flags: transfer ack flags
- *
- * Return: Async transaction descriptor on success and NULL on failure
- */
-static struct dma_async_tx_descriptor *
-mv_xor_prep_dma_sg(struct dma_chan *chan, struct scatterlist *dst_sg,
-		   unsigned int dst_sg_len, struct scatterlist *src_sg,
-		   unsigned int src_sg_len, unsigned long flags)
-{
-	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
-	struct mv_xor_desc_slot *new;
-	struct mv_xor_desc_slot *first = NULL;
-	struct mv_xor_desc_slot *prev = NULL;
-	size_t len, dst_avail, src_avail;
-	dma_addr_t dma_dst, dma_src;
-	int desc_cnt = 0;
-	int ret;
-
-	dev_dbg(mv_chan_to_devp(mv_chan),
-		"%s dst_sg_len: %d src_sg_len: %d flags: %ld\n",
-		__func__, dst_sg_len, src_sg_len, flags);
-
-	dst_avail = sg_dma_len(dst_sg);
-	src_avail = sg_dma_len(src_sg);
-
-	/* Run until we are out of scatterlist entries */
-	while (true) {
-		/* Allocate and populate the descriptor */
-		desc_cnt++;
-		new = mv_chan_alloc_slot(mv_chan);
-		if (!new) {
-			dev_err(mv_chan_to_devp(mv_chan),
-				"Out of descriptors (desc_cnt=%d)!\n",
-				desc_cnt);
-			goto err;
-		}
-
-		len = min_t(size_t, src_avail, dst_avail);
-		len = min_t(size_t, len, MV_XOR_MAX_BYTE_COUNT);
-		if (len == 0)
-			goto fetch;
-
-		if (len < MV_XOR_MIN_BYTE_COUNT) {
-			dev_err(mv_chan_to_devp(mv_chan),
-				"Transfer size of %zu too small!\n", len);
-			goto err;
-		}
-
-		dma_dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) -
-			dst_avail;
-		dma_src = sg_dma_address(src_sg) + sg_dma_len(src_sg) -
-			src_avail;
-
-		/* Check if a new window needs to get added for 'dst' */
-		ret = mv_xor_add_io_win(mv_chan, dma_dst);
-		if (ret)
-			goto err;
-
-		/* Check if a new window needs to get added for 'src' */
-		ret = mv_xor_add_io_win(mv_chan, dma_src);
-		if (ret)
-			goto err;
-
-		/* Populate the descriptor */
-		mv_xor_config_sg_ll_desc(new, dma_src, dma_dst, len, prev);
-		prev = new;
-		dst_avail -= len;
-		src_avail -= len;
-
-		if (!first)
-			first = new;
-		else
-			list_move_tail(&new->node, &first->sg_tx_list);
-
-fetch:
-		/* Fetch the next dst scatterlist entry */
-		if (dst_avail == 0) {
-			if (dst_sg_len == 0)
-				break;
-
-			/* Fetch the next entry: if there are no more: done */
-			dst_sg = sg_next(dst_sg);
-			if (dst_sg == NULL)
-				break;
-
-			dst_sg_len--;
-			dst_avail = sg_dma_len(dst_sg);
-		}
-
-		/* Fetch the next src scatterlist entry */
-		if (src_avail == 0) {
-			if (src_sg_len == 0)
-				break;
-
-			/* Fetch the next entry: if there are no more: done */
-			src_sg = sg_next(src_sg);
-			if (src_sg == NULL)
-				break;
-
-			src_sg_len--;
-			src_avail = sg_dma_len(src_sg);
-		}
-	}
-
-	/* Set the EOD flag in the last descriptor */
-	mv_xor_desc_config_eod(new);
-	first->async_tx.flags = flags;
-
-	return &first->async_tx;
-
-err:
-	/* Cleanup: Move all descriptors back into the free list */
-	spin_lock_bh(&mv_chan->lock);
-	mv_desc_clean_slot(first, mv_chan);
-	spin_unlock_bh(&mv_chan->lock);
-
-	return NULL;
-}
-
 static void mv_xor_free_chan_resources(struct dma_chan *chan)
 {
 	struct mv_xor_chan *mv_chan = to_mv_xor_chan(chan);
@@ -1254,8 +1098,6 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
 		dma_dev->device_prep_dma_interrupt = mv_xor_prep_dma_interrupt;
 	if (dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask))
 		dma_dev->device_prep_dma_memcpy = mv_xor_prep_dma_memcpy;
-	if (dma_has_cap(DMA_SG, dma_dev->cap_mask))
-		dma_dev->device_prep_dma_sg = mv_xor_prep_dma_sg;
 	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
 		dma_dev->max_xor = 8;
 		dma_dev->device_prep_dma_xor = mv_xor_prep_dma_xor;
@@ -1305,11 +1147,10 @@ mv_xor_channel_add(struct mv_xor_device *xordev,
 			goto err_free_irq;
 	}
 
-	dev_info(&pdev->dev, "Marvell XOR (%s): ( %s%s%s%s)\n",
+	dev_info(&pdev->dev, "Marvell XOR (%s): ( %s%s%s)\n",
 		 mv_chan->op_in_desc ? "Descriptor Mode" : "Registers Mode",
 		 dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "xor " : "",
 		 dma_has_cap(DMA_MEMCPY, dma_dev->cap_mask) ? "cpy " : "",
-		 dma_has_cap(DMA_SG, dma_dev->cap_mask) ? "sg " : "",
 		 dma_has_cap(DMA_INTERRUPT, dma_dev->cap_mask) ? "intr " : "");
 
 	dma_async_device_register(dma_dev);
@@ -1552,7 +1393,6 @@ static int mv_xor_probe(struct platform_device *pdev)
 
 			dma_cap_zero(cap_mask);
 			dma_cap_set(DMA_MEMCPY, cap_mask);
-			dma_cap_set(DMA_SG, cap_mask);
 			dma_cap_set(DMA_XOR, cap_mask);
 			dma_cap_set(DMA_INTERRUPT, cap_mask);
 
diff --git a/drivers/dma/nbpfaxi.c b/drivers/dma/nbpfaxi.c
index 3f45b9bdf201..d3f918a9ee76 100644
--- a/drivers/dma/nbpfaxi.c
+++ b/drivers/dma/nbpfaxi.c
@@ -1005,21 +1005,6 @@ static struct dma_async_tx_descriptor *nbpf_prep_memcpy(
 			    DMA_MEM_TO_MEM, flags);
 }
 
-static struct dma_async_tx_descriptor *nbpf_prep_memcpy_sg(
-	struct dma_chan *dchan,
-	struct scatterlist *dst_sg, unsigned int dst_nents,
-	struct scatterlist *src_sg, unsigned int src_nents,
-	unsigned long flags)
-{
-	struct nbpf_channel *chan = nbpf_to_chan(dchan);
-
-	if (dst_nents != src_nents)
-		return NULL;
-
-	return nbpf_prep_sg(chan, src_sg, dst_sg, src_nents,
-			    DMA_MEM_TO_MEM, flags);
-}
-
 static struct dma_async_tx_descriptor *nbpf_prep_slave_sg(
 	struct dma_chan *dchan, struct scatterlist *sgl, unsigned int sg_len,
 	enum dma_transfer_direction direction, unsigned long flags, void *context)
@@ -1417,13 +1402,11 @@ static int nbpf_probe(struct platform_device *pdev)
 	dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
 	dma_cap_set(DMA_SLAVE, dma_dev->cap_mask);
 	dma_cap_set(DMA_PRIVATE, dma_dev->cap_mask);
-	dma_cap_set(DMA_SG, dma_dev->cap_mask);
 
 	/* Common and MEMCPY operations */
 	dma_dev->device_alloc_chan_resources
 		= nbpf_alloc_chan_resources;
 	dma_dev->device_free_chan_resources = nbpf_free_chan_resources;
-	dma_dev->device_prep_dma_sg = nbpf_prep_memcpy_sg;
 	dma_dev->device_prep_dma_memcpy = nbpf_prep_memcpy;
 	dma_dev->device_tx_status = nbpf_tx_status;
 	dma_dev->device_issue_pending = nbpf_issue_pending;
diff --git a/drivers/dma/ste_dma40.c b/drivers/dma/ste_dma40.c
index c3052fbfd092..97e1d8b00e22 100644
--- a/drivers/dma/ste_dma40.c
+++ b/drivers/dma/ste_dma40.c
@@ -2485,19 +2485,6 @@ static struct dma_async_tx_descriptor *d40_prep_memcpy(struct dma_chan *chan,
 }
 
 static struct dma_async_tx_descriptor *
-d40_prep_memcpy_sg(struct dma_chan *chan,
-		   struct scatterlist *dst_sg, unsigned int dst_nents,
-		   struct scatterlist *src_sg, unsigned int src_nents,
-		   unsigned long dma_flags)
-{
-	if (dst_nents != src_nents)
-		return NULL;
-
-	return d40_prep_sg(chan, src_sg, dst_sg, src_nents,
-			   DMA_MEM_TO_MEM, dma_flags);
-}
-
-static struct dma_async_tx_descriptor *
 d40_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 		  unsigned int sg_len, enum dma_transfer_direction direction,
 		  unsigned long dma_flags, void *context)
@@ -2821,9 +2808,6 @@ static void d40_ops_init(struct d40_base *base, struct dma_device *dev)
 		dev->copy_align = DMAENGINE_ALIGN_4_BYTES;
 	}
 
-	if (dma_has_cap(DMA_SG, dev->cap_mask))
-		dev->device_prep_dma_sg = d40_prep_memcpy_sg;
-
 	if (dma_has_cap(DMA_CYCLIC, dev->cap_mask))
 		dev->device_prep_dma_cyclic = dma40_prep_dma_cyclic;
 
@@ -2865,7 +2849,6 @@ static int __init d40_dmaengine_init(struct d40_base *base,
 
 	dma_cap_zero(base->dma_memcpy.cap_mask);
 	dma_cap_set(DMA_MEMCPY, base->dma_memcpy.cap_mask);
-	dma_cap_set(DMA_SG, base->dma_memcpy.cap_mask);
 
 	d40_ops_init(base, &base->dma_memcpy);
 
@@ -2883,7 +2866,6 @@ static int __init d40_dmaengine_init(struct d40_base *base,
 	dma_cap_zero(base->dma_both.cap_mask);
 	dma_cap_set(DMA_SLAVE, base->dma_both.cap_mask);
 	dma_cap_set(DMA_MEMCPY, base->dma_both.cap_mask);
-	dma_cap_set(DMA_SG, base->dma_both.cap_mask);
 	dma_cap_set(DMA_CYCLIC, base->dma_slave.cap_mask);
 
 	d40_ops_init(base, &base->dma_both);
diff --git a/drivers/dma/xgene-dma.c b/drivers/dma/xgene-dma.c
index 8b693b712d0f..8648d2394ab6 100644
--- a/drivers/dma/xgene-dma.c
+++ b/drivers/dma/xgene-dma.c
@@ -425,48 +425,6 @@ static void xgene_dma_init_desc(struct xgene_dma_desc_hw *desc,
 				XGENE_DMA_DESC_HOENQ_NUM_POS);
 }
 
-static void xgene_dma_prep_cpy_desc(struct xgene_dma_chan *chan,
-				    struct xgene_dma_desc_sw *desc_sw,
-				    dma_addr_t dst, dma_addr_t src,
-				    size_t len)
-{
-	struct xgene_dma_desc_hw *desc1, *desc2;
-	int i;
-
-	/* Get 1st descriptor */
-	desc1 = &desc_sw->desc1;
-	xgene_dma_init_desc(desc1, chan->tx_ring.dst_ring_num);
-
-	/* Set destination address */
-	desc1->m2 |= cpu_to_le64(XGENE_DMA_DESC_DR_BIT);
-	desc1->m3 |= cpu_to_le64(dst);
-
-	/* Set 1st source address */
-	xgene_dma_set_src_buffer(&desc1->m1, &len, &src);
-
-	if (!len)
-		return;
-
-	/*
-	 * We need to split this source buffer,
-	 * and need to use 2nd descriptor
-	 */
-	desc2 = &desc_sw->desc2;
-	desc1->m0 |= cpu_to_le64(XGENE_DMA_DESC_NV_BIT);
-
-	/* Set 2nd to 5th source address */
-	for (i = 0; i < 4 && len; i++)
-		xgene_dma_set_src_buffer(xgene_dma_lookup_ext8(desc2, i),
-					 &len, &src);
-
-	/* Invalidate unused source address field */
-	for (; i < 4; i++)
-		xgene_dma_invalidate_buffer(xgene_dma_lookup_ext8(desc2, i));
-
-	/* Updated flag that we have prepared 64B descriptor */
-	desc_sw->flags |= XGENE_DMA_FLAG_64B_DESC;
-}
-
 static void xgene_dma_prep_xor_desc(struct xgene_dma_chan *chan,
 				    struct xgene_dma_desc_sw *desc_sw,
 				    dma_addr_t *dst, dma_addr_t *src,
@@ -891,114 +849,6 @@ static void xgene_dma_free_chan_resources(struct dma_chan *dchan)
 	chan->desc_pool = NULL;
 }
 
-static struct dma_async_tx_descriptor *xgene_dma_prep_sg(
-	struct dma_chan *dchan, struct scatterlist *dst_sg,
-	u32 dst_nents, struct scatterlist *src_sg,
-	u32 src_nents, unsigned long flags)
-{
-	struct xgene_dma_desc_sw *first = NULL, *new = NULL;
-	struct xgene_dma_chan *chan;
-	size_t dst_avail, src_avail;
-	dma_addr_t dst, src;
-	size_t len;
-
-	if (unlikely(!dchan))
-		return NULL;
-
-	if (unlikely(!dst_nents || !src_nents))
-		return NULL;
-
-	if (unlikely(!dst_sg || !src_sg))
-		return NULL;
-
-	chan = to_dma_chan(dchan);
-
-	/* Get prepared for the loop */
-	dst_avail = sg_dma_len(dst_sg);
-	src_avail = sg_dma_len(src_sg);
-	dst_nents--;
-	src_nents--;
-
-	/* Run until we are out of scatterlist entries */
-	while (true) {
-		/* Create the largest transaction possible */
-		len = min_t(size_t, src_avail, dst_avail);
-		len = min_t(size_t, len, XGENE_DMA_MAX_64B_DESC_BYTE_CNT);
-		if (len == 0)
-			goto fetch;
-
-		dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) - dst_avail;
-		src = sg_dma_address(src_sg) + sg_dma_len(src_sg) - src_avail;
-
-		/* Allocate the link descriptor from DMA pool */
-		new = xgene_dma_alloc_descriptor(chan);
-		if (!new)
-			goto fail;
-
-		/* Prepare DMA descriptor */
-		xgene_dma_prep_cpy_desc(chan, new, dst, src, len);
-
-		if (!first)
-			first = new;
-
-		new->tx.cookie = 0;
-		async_tx_ack(&new->tx);
-
-		/* update metadata */
-		dst_avail -= len;
-		src_avail -= len;
-
-		/* Insert the link descriptor to the LD ring */
-		list_add_tail(&new->node, &first->tx_list);
-
-fetch:
-		/* fetch the next dst scatterlist entry */
-		if (dst_avail == 0) {
-			/* no more entries: we're done */
-			if (dst_nents == 0)
-				break;
-
-			/* fetch the next entry: if there are no more: done */
-			dst_sg = sg_next(dst_sg);
-			if (!dst_sg)
-				break;
-
-			dst_nents--;
-			dst_avail = sg_dma_len(dst_sg);
-		}
-
-		/* fetch the next src scatterlist entry */
-		if (src_avail == 0) {
-			/* no more entries: we're done */
-			if (src_nents == 0)
-				break;
-
-			/* fetch the next entry: if there are no more: done */
-			src_sg = sg_next(src_sg);
-			if (!src_sg)
-				break;
-
-			src_nents--;
-			src_avail = sg_dma_len(src_sg);
-		}
-	}
-
-	if (!new)
-		return NULL;
-
-	new->tx.flags = flags; /* client is in control of this ack */
-	new->tx.cookie = -EBUSY;
-	list_splice(&first->tx_list, &new->tx_list);
-
-	return &new->tx;
-fail:
-	if (!first)
-		return NULL;
-
-	xgene_dma_free_desc_list(chan, &first->tx_list);
-	return NULL;
-}
-
 static struct dma_async_tx_descriptor *xgene_dma_prep_xor(
 	struct dma_chan *dchan, dma_addr_t dst,	dma_addr_t *src,
 	u32 src_cnt, size_t len, unsigned long flags)
@@ -1653,7 +1503,6 @@ static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
 	dma_cap_zero(dma_dev->cap_mask);
 
 	/* Set DMA device capability */
-	dma_cap_set(DMA_SG, dma_dev->cap_mask);
 
 	/* Basically here, the X-Gene SoC DMA engine channel 0 supports XOR
 	 * and channel 1 supports XOR, PQ both. First thing here is we have
@@ -1679,7 +1528,6 @@ static void xgene_dma_set_caps(struct xgene_dma_chan *chan,
 	dma_dev->device_free_chan_resources = xgene_dma_free_chan_resources;
 	dma_dev->device_issue_pending = xgene_dma_issue_pending;
 	dma_dev->device_tx_status = xgene_dma_tx_status;
-	dma_dev->device_prep_dma_sg = xgene_dma_prep_sg;
 
 	if (dma_has_cap(DMA_XOR, dma_dev->cap_mask)) {
 		dma_dev->device_prep_dma_xor = xgene_dma_prep_xor;
@@ -1731,8 +1579,7 @@ static int xgene_dma_async_register(struct xgene_dma *pdma, int id)
 
 	/* DMA capability info */
 	dev_info(pdma->dev,
-		 "%s: CAPABILITY ( %s%s%s)\n", dma_chan_name(&chan->dma_chan),
-		 dma_has_cap(DMA_SG, dma_dev->cap_mask) ? "SGCPY " : "",
+		 "%s: CAPABILITY ( %s%s)\n", dma_chan_name(&chan->dma_chan),
 		 dma_has_cap(DMA_XOR, dma_dev->cap_mask) ? "XOR " : "",
 		 dma_has_cap(DMA_PQ, dma_dev->cap_mask) ? "PQ " : "");
 
diff --git a/drivers/dma/xilinx/zynqmp_dma.c b/drivers/dma/xilinx/zynqmp_dma.c
index 47f64192d2fd..1ee1241ca797 100644
--- a/drivers/dma/xilinx/zynqmp_dma.c
+++ b/drivers/dma/xilinx/zynqmp_dma.c
@@ -830,98 +830,6 @@ static struct dma_async_tx_descriptor *zynqmp_dma_prep_memcpy(
 }
 
 /**
- * zynqmp_dma_prep_slave_sg - prepare descriptors for a memory sg transaction
- * @dchan: DMA channel
- * @dst_sg: Destination scatter list
- * @dst_sg_len: Number of entries in destination scatter list
- * @src_sg: Source scatter list
- * @src_sg_len: Number of entries in source scatter list
- * @flags: transfer ack flags
- *
- * Return: Async transaction descriptor on success and NULL on failure
- */
-static struct dma_async_tx_descriptor *zynqmp_dma_prep_sg(
-			struct dma_chan *dchan, struct scatterlist *dst_sg,
-			unsigned int dst_sg_len, struct scatterlist *src_sg,
-			unsigned int src_sg_len, unsigned long flags)
-{
-	struct zynqmp_dma_desc_sw *new, *first = NULL;
-	struct zynqmp_dma_chan *chan = to_chan(dchan);
-	void *desc = NULL, *prev = NULL;
-	size_t len, dst_avail, src_avail;
-	dma_addr_t dma_dst, dma_src;
-	u32 desc_cnt = 0, i;
-	struct scatterlist *sg;
-
-	for_each_sg(src_sg, sg, src_sg_len, i)
-		desc_cnt += DIV_ROUND_UP(sg_dma_len(sg),
-					 ZYNQMP_DMA_MAX_TRANS_LEN);
-
-	spin_lock_bh(&chan->lock);
-	if (desc_cnt > chan->desc_free_cnt) {
-		spin_unlock_bh(&chan->lock);
-		dev_dbg(chan->dev, "chan %p descs are not available\n", chan);
-		return NULL;
-	}
-	chan->desc_free_cnt = chan->desc_free_cnt - desc_cnt;
-	spin_unlock_bh(&chan->lock);
-
-	dst_avail = sg_dma_len(dst_sg);
-	src_avail = sg_dma_len(src_sg);
-
-	/* Run until we are out of scatterlist entries */
-	while (true) {
-		/* Allocate and populate the descriptor */
-		new = zynqmp_dma_get_descriptor(chan);
-		desc = (struct zynqmp_dma_desc_ll *)new->src_v;
-		len = min_t(size_t, src_avail, dst_avail);
-		len = min_t(size_t, len, ZYNQMP_DMA_MAX_TRANS_LEN);
-		if (len == 0)
-			goto fetch;
-		dma_dst = sg_dma_address(dst_sg) + sg_dma_len(dst_sg) -
-			dst_avail;
-		dma_src = sg_dma_address(src_sg) + sg_dma_len(src_sg) -
-			src_avail;
-
-		zynqmp_dma_config_sg_ll_desc(chan, desc, dma_src, dma_dst,
-					     len, prev);
-		prev = desc;
-		dst_avail -= len;
-		src_avail -= len;
-
-		if (!first)
-			first = new;
-		else
-			list_add_tail(&new->node, &first->tx_list);
-fetch:
-		/* Fetch the next dst scatterlist entry */
-		if (dst_avail == 0) {
-			if (dst_sg_len == 0)
-				break;
-			dst_sg = sg_next(dst_sg);
-			if (dst_sg == NULL)
-				break;
-			dst_sg_len--;
-			dst_avail = sg_dma_len(dst_sg);
-		}
-		/* Fetch the next src scatterlist entry */
-		if (src_avail == 0) {
-			if (src_sg_len == 0)
-				break;
-			src_sg = sg_next(src_sg);
-			if (src_sg == NULL)
-				break;
-			src_sg_len--;
-			src_avail = sg_dma_len(src_sg);
-		}
-	}
-
-	zynqmp_dma_desc_config_eod(chan, desc);
-	first->async_tx.flags = flags;
-	return &first->async_tx;
-}
-
-/**
  * zynqmp_dma_chan_remove - Channel remove function
  * @chan: ZynqMP DMA channel pointer
  */
@@ -1064,11 +972,9 @@ static int zynqmp_dma_probe(struct platform_device *pdev)
 	INIT_LIST_HEAD(&zdev->common.channels);
 
 	dma_set_mask(&pdev->dev, DMA_BIT_MASK(44));
-	dma_cap_set(DMA_SG, zdev->common.cap_mask);
 	dma_cap_set(DMA_MEMCPY, zdev->common.cap_mask);
 
 	p = &zdev->common;
-	p->device_prep_dma_sg = zynqmp_dma_prep_sg;
 	p->device_prep_dma_memcpy = zynqmp_dma_prep_memcpy;
 	p->device_terminate_all = zynqmp_dma_device_terminate_all;
 	p->device_issue_pending = zynqmp_dma_issue_pending;