5 files changed, 137 insertions, 80 deletions

diff --git a/drivers/dma/amba-pl08x.c b/drivers/dma/amba-pl08x.c
index 4a5fd245014e..83aa55d6fa5d 100644
--- a/drivers/dma/amba-pl08x.c
+++ b/drivers/dma/amba-pl08x.c
@@ -97,6 +97,12 @@
 
 #define DRIVER_NAME	"pl08xdmac"
 
+#define PL80X_DMA_BUSWIDTHS \
+	BIT(DMA_SLAVE_BUSWIDTH_UNDEFINED) | \
+	BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
+	BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
+	BIT(DMA_SLAVE_BUSWIDTH_4_BYTES)
+
 static struct amba_driver pl08x_amba_driver;
 struct pl08x_driver_data;
 
@@ -2070,6 +2076,10 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
 	pl08x->memcpy.device_pause = pl08x_pause;
 	pl08x->memcpy.device_resume = pl08x_resume;
 	pl08x->memcpy.device_terminate_all = pl08x_terminate_all;
+	pl08x->memcpy.src_addr_widths = PL80X_DMA_BUSWIDTHS;
+	pl08x->memcpy.dst_addr_widths = PL80X_DMA_BUSWIDTHS;
+	pl08x->memcpy.directions = BIT(DMA_MEM_TO_MEM);
+	pl08x->memcpy.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
 
 	/* Initialize slave engine */
 	dma_cap_set(DMA_SLAVE, pl08x->slave.cap_mask);
@@ -2086,6 +2096,10 @@ static int pl08x_probe(struct amba_device *adev, const struct amba_id *id)
 	pl08x->slave.device_pause = pl08x_pause;
 	pl08x->slave.device_resume = pl08x_resume;
 	pl08x->slave.device_terminate_all = pl08x_terminate_all;
+	pl08x->slave.src_addr_widths = PL80X_DMA_BUSWIDTHS;
+	pl08x->slave.dst_addr_widths = PL80X_DMA_BUSWIDTHS;
+	pl08x->slave.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+	pl08x->slave.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;
 
 	/* Get the platform data */
 	pl08x->pd = dev_get_platdata(&adev->dev);
diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 1e1a4c567542..0b4fc6fb48ce 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -238,93 +238,126 @@ static void atc_dostart(struct at_dma_chan *atchan, struct at_desc *first)
 }
 
 /*
- * atc_get_current_descriptors -
- * locate the descriptor which equal to physical address in DSCR
- * @atchan: the channel we want to start
- * @dscr_addr: physical descriptor address in DSCR
+ * atc_get_desc_by_cookie - get the descriptor of a cookie
+ * @atchan: the DMA channel
+ * @cookie: the cookie to get the descriptor for
  */
-static struct at_desc *atc_get_current_descriptors(struct at_dma_chan *atchan,
-							u32 dscr_addr)
+static struct at_desc *atc_get_desc_by_cookie(struct at_dma_chan *atchan,
+						dma_cookie_t cookie)
 {
-	struct at_desc  *desc, *_desc, *child, *desc_cur = NULL;
+	struct at_desc *desc, *_desc;
 
-	list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) {
-		if (desc->lli.dscr == dscr_addr) {
-			desc_cur = desc;
-			break;
-		}
+	list_for_each_entry_safe(desc, _desc, &atchan->queue, desc_node) {
+		if (desc->txd.cookie == cookie)
+			return desc;
+	}
 
-		list_for_each_entry(child, &desc->tx_list, desc_node) {
-			if (child->lli.dscr == dscr_addr) {
-				desc_cur = child;
-				break;
-			}
-		}
+	list_for_each_entry_safe(desc, _desc, &atchan->active_list, desc_node) {
+		if (desc->txd.cookie == cookie)
+			return desc;
 	}
 
-	return desc_cur;
+	return NULL;
 }
 
-/*
- * atc_get_bytes_left -
- * Get the number of bytes residue in dma buffer,
- * @chan: the channel we want to start
+/**
+ * atc_calc_bytes_left - calculates the number of bytes left according to the
+ * value read from CTRLA.
+ *
+ * @current_len: the number of bytes left before reading CTRLA
+ * @ctrla: the value of CTRLA
+ * @desc: the descriptor containing the transfer width
+ */
+static inline int atc_calc_bytes_left(int current_len, u32 ctrla,
+					struct at_desc *desc)
+{
+	return current_len - ((ctrla & ATC_BTSIZE_MAX) << desc->tx_width);
+}
+
+/**
+ * atc_calc_bytes_left_from_reg - calculates the number of bytes left according
+ * to the current value of CTRLA.
+ *
+ * @current_len: the number of bytes left before reading CTRLA
+ * @atchan: the channel to read CTRLA for
+ * @desc: the descriptor containing the transfer width
+ */
+static inline int atc_calc_bytes_left_from_reg(int current_len,
+			struct at_dma_chan *atchan, struct at_desc *desc)
+{
+	u32 ctrla = channel_readl(atchan, CTRLA);
+
+	return atc_calc_bytes_left(current_len, ctrla, desc);
+}
+
+/**
+ * atc_get_bytes_left - get the number of bytes residue for a cookie
+ * @chan: DMA channel
+ * @cookie: transaction identifier to check status of
  */
-static int atc_get_bytes_left(struct dma_chan *chan)
+static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie)
 {
 	struct at_dma_chan      *atchan = to_at_dma_chan(chan);
-	struct at_dma           *atdma = to_at_dma(chan->device);
-	int	chan_id = atchan->chan_common.chan_id;
 	struct at_desc *desc_first = atc_first_active(atchan);
-	struct at_desc *desc_cur;
-	int ret = 0, count = 0;
+	struct at_desc *desc;
+	int ret;
+	u32 ctrla, dscr;
 
 	/*
-	 * Initialize necessary values in the first time.
-	 * remain_desc record remain desc length.
+	 * If the cookie doesn't match to the currently running transfer then
+	 * we can return the total length of the associated DMA transfer,
+	 * because it is still queued.
 	 */
-	if (atchan->remain_desc == 0)
-		/* First descriptor embedds the transaction length */
-		atchan->remain_desc = desc_first->len;
+	desc = atc_get_desc_by_cookie(atchan, cookie);
+	if (desc == NULL)
+		return -EINVAL;
+	else if (desc != desc_first)
+		return desc->total_len;
 
-	/*
-	 * This happens when current descriptor transfer complete.
-	 * The residual buffer size should reduce current descriptor length.
-	 */
-	if (unlikely(test_bit(ATC_IS_BTC, &atchan->status))) {
-		clear_bit(ATC_IS_BTC, &atchan->status);
-		desc_cur = atc_get_current_descriptors(atchan,
-						channel_readl(atchan, DSCR));
-		if (!desc_cur) {
-			ret = -EINVAL;
-			goto out;
-		}
+	/* cookie matches to the currently running transfer */
+	ret = desc_first->total_len;
 
-		count = (desc_cur->lli.ctrla & ATC_BTSIZE_MAX)
-			<< desc_first->tx_width;
-		if (atchan->remain_desc < count) {
-			ret = -EINVAL;
-			goto out;
+	if (desc_first->lli.dscr) {
+		/* hardware linked list transfer */
+
+		/*
+		 * Calculate the residue by removing the length of the child
+		 * descriptors already transferred from the total length.
+		 * To get the current child descriptor we can use the value of
+		 * the channel's DSCR register and compare it against the value
+		 * of the hardware linked list structure of each child
+		 * descriptor.
+		 */
+
+		ctrla = channel_readl(atchan, CTRLA);
+		rmb(); /* ensure CTRLA is read before DSCR */
+		dscr = channel_readl(atchan, DSCR);
+
+		/* for the first descriptor we can be more accurate */
+		if (desc_first->lli.dscr == dscr)
+			return atc_calc_bytes_left(ret, ctrla, desc_first);
+
+		ret -= desc_first->len;
+		list_for_each_entry(desc, &desc_first->tx_list, desc_node) {
+			if (desc->lli.dscr == dscr)
+				break;
+
+			ret -= desc->len;
 		}
 
-		atchan->remain_desc -= count;
-		ret = atchan->remain_desc;
-	} else {
 		/*
-		 * Get residual bytes when current
-		 * descriptor transfer in progress.
+		 * For the last descriptor in the chain we can calculate
+		 * the remaining bytes using the channel's register.
+		 * Note that the transfer width of the first and last
+		 * descriptor may differ.
 		 */
-		count = (channel_readl(atchan, CTRLA) & ATC_BTSIZE_MAX)
-				<< (desc_first->tx_width);
-		ret = atchan->remain_desc - count;
+		if (!desc->lli.dscr)
+			ret = atc_calc_bytes_left_from_reg(ret, atchan, desc);
+	} else {
+		/* single transfer */
+		ret = atc_calc_bytes_left_from_reg(ret, atchan, desc_first);
 	}
-	/*
-	 * Check fifo empty.
-	 */
-	if (!(dma_readl(atdma, CHSR) & AT_DMA_EMPT(chan_id)))
-		atc_issue_pending(chan);
 
-out:
 	return ret;
 }
 
@@ -539,8 +572,6 @@ static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
 					/* Give information to tasklet */
 					set_bit(ATC_IS_ERROR, &atchan->status);
 				}
-				if (pending & AT_DMA_BTC(i))
-					set_bit(ATC_IS_BTC, &atchan->status);
 				tasklet_schedule(&atchan->tasklet);
 				ret = IRQ_HANDLED;
 			}
@@ -653,14 +684,18 @@ atc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 		desc->lli.ctrlb = ctrlb;
 
 		desc->txd.cookie = 0;
+		desc->len = xfer_count << src_width;
 
 		atc_desc_chain(&first, &prev, desc);
 	}
 
 	/* First descriptor of the chain embedds additional information */
 	first->txd.cookie = -EBUSY;
-	first->len = len;
+	first->total_len = len;
+
+	/* set transfer width for the calculation of the residue */
 	first->tx_width = src_width;
+	prev->tx_width = src_width;
 
 	/* set end-of-link to the last link descriptor of list*/
 	set_desc_eol(desc);
@@ -752,6 +787,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 					| ATC_SRC_WIDTH(mem_width)
 					| len >> mem_width;
 			desc->lli.ctrlb = ctrlb;
+			desc->len = len;
 
 			atc_desc_chain(&first, &prev, desc);
 			total_len += len;
@@ -792,6 +828,7 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 					| ATC_DST_WIDTH(mem_width)
 					| len >> reg_width;
 			desc->lli.ctrlb = ctrlb;
+			desc->len = len;
 
 			atc_desc_chain(&first, &prev, desc);
 			total_len += len;
@@ -806,8 +843,11 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
 	/* First descriptor of the chain embedds additional information */
 	first->txd.cookie = -EBUSY;
-	first->len = total_len;
+	first->total_len = total_len;
+
+	/* set transfer width for the calculation of the residue */
 	first->tx_width = reg_width;
+	prev->tx_width = reg_width;
 
 	/* first link descriptor of list is responsible of flags */
 	first->txd.flags = flags; /* client is in control of this ack */
@@ -872,6 +912,7 @@ atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
 				| ATC_FC_MEM2PER
 				| ATC_SIF(atchan->mem_if)
 				| ATC_DIF(atchan->per_if);
+		desc->len = period_len;
 		break;
 
 	case DMA_DEV_TO_MEM:
@@ -883,6 +924,7 @@ atc_dma_cyclic_fill_desc(struct dma_chan *chan, struct at_desc *desc,
 				| ATC_FC_PER2MEM
 				| ATC_SIF(atchan->per_if)
 				| ATC_DIF(atchan->mem_if);
+		desc->len = period_len;
 		break;
 
 	default:
@@ -964,7 +1006,7 @@ atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
 
 	/* First descriptor of the chain embedds additional information */
 	first->txd.cookie = -EBUSY;
-	first->len = buf_len;
+	first->total_len = buf_len;
 	first->tx_width = reg_width;
 
 	return &first->txd;
@@ -1118,7 +1160,7 @@ atc_tx_status(struct dma_chan *chan,
 	spin_lock_irqsave(&atchan->lock, flags);
 
 	/*  Get number of bytes left in the active transactions */
-	bytes = atc_get_bytes_left(chan);
+	bytes = atc_get_bytes_left(chan, cookie);
 
 	spin_unlock_irqrestore(&atchan->lock, flags);
 
@@ -1214,7 +1256,6 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
 
 	spin_lock_irqsave(&atchan->lock, flags);
 	atchan->descs_allocated = i;
-	atchan->remain_desc = 0;
 	list_splice(&tmp_list, &atchan->free_list);
 	dma_cookie_init(chan);
 	spin_unlock_irqrestore(&atchan->lock, flags);
@@ -1257,7 +1298,6 @@ static void atc_free_chan_resources(struct dma_chan *chan)
 	list_splice_init(&atchan->free_list, &list);
 	atchan->descs_allocated = 0;
 	atchan->status = 0;
-	atchan->remain_desc = 0;
 
 	dev_vdbg(chan2dev(chan), "free_chan_resources: done\n");
 }
diff --git a/drivers/dma/at_hdmac_regs.h b/drivers/dma/at_hdmac_regs.h
index d6bba6c636c2..2727ca560572 100644
--- a/drivers/dma/at_hdmac_regs.h
+++ b/drivers/dma/at_hdmac_regs.h
@@ -181,8 +181,9 @@ struct at_lli {
  * @at_lli: hardware lli structure
  * @txd: support for the async_tx api
  * @desc_node: node on the channed descriptors list
- * @len: total transaction bytecount
+ * @len: descriptor byte count
  * @tx_width: transfer width
+ * @total_len: total transaction byte count
  */
 struct at_desc {
 	/* FIRST values the hardware uses */
@@ -194,6 +195,7 @@ struct at_desc {
 	struct list_head		desc_node;
 	size_t				len;
 	u32				tx_width;
+	size_t				total_len;
 };
 
 static inline struct at_desc *
@@ -213,7 +215,6 @@ txd_to_at_desc(struct dma_async_tx_descriptor *txd)
 enum atc_status {
 	ATC_IS_ERROR = 0,
 	ATC_IS_PAUSED = 1,
-	ATC_IS_BTC = 2,
 	ATC_IS_CYCLIC = 24,
 };
 
@@ -231,7 +232,6 @@ enum atc_status {
  * @save_cfg: configuration register that is saved on suspend/resume cycle
  * @save_dscr: for cyclic operations, preserve next descriptor address in
  *             the cyclic list on suspend/resume cycle
- * @remain_desc: to save remain desc length
  * @dma_sconfig: configuration for slave transfers, passed via
  * .device_config
  * @lock: serializes enqueue/dequeue operations to descriptors lists
@@ -251,7 +251,6 @@ struct at_dma_chan {
 	struct tasklet_struct	tasklet;
 	u32			save_cfg;
 	u32			save_dscr;
-	u32			remain_desc;
 	struct dma_slave_config dma_sconfig;
 
 	spinlock_t		lock;
diff --git a/drivers/dma/dw/platform.c b/drivers/dma/dw/platform.c
index 6565a361e7e5..b2c3ae071429 100644
--- a/drivers/dma/dw/platform.c
+++ b/drivers/dma/dw/platform.c
@@ -26,6 +26,8 @@
 
 #include "internal.h"
 
+#define DRV_NAME	"dw_dmac"
+
 static struct dma_chan *dw_dma_of_xlate(struct of_phandle_args *dma_spec,
 					struct of_dma *ofdma)
 {
@@ -284,7 +286,7 @@ static struct platform_driver dw_driver = {
 	.remove		= dw_remove,
 	.shutdown       = dw_shutdown,
 	.driver = {
-		.name	= "dw_dmac",
+		.name	= DRV_NAME,
 		.pm	= &dw_dev_pm_ops,
 		.of_match_table = of_match_ptr(dw_dma_of_id_table),
 		.acpi_match_table = ACPI_PTR(dw_dma_acpi_id_table),
@@ -305,3 +307,4 @@ module_exit(dw_exit);
 
 MODULE_LICENSE("GPL v2");
 MODULE_DESCRIPTION("Synopsys DesignWare DMA Controller platform driver");
+MODULE_ALIAS("platform:" DRV_NAME);
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c
index 18c0a131e4e4..66a0efb9651d 100644
--- a/drivers/dma/imx-sdma.c
+++ b/drivers/dma/imx-sdma.c
@@ -531,6 +531,10 @@ static int sdma_run_channel0(struct sdma_engine *sdma)
 		dev_err(sdma->dev, "Timeout waiting for CH0 ready\n");
 	}
 
+	/* Set bits of CONFIG register with dynamic context switching */
+	if (readl(sdma->regs + SDMA_H_CONFIG) == 0)
+		writel_relaxed(SDMA_H_CONFIG_CSM, sdma->regs + SDMA_H_CONFIG);
+
 	return ret ? 0 : -ETIMEDOUT;
 }
 
@@ -1394,9 +1398,6 @@ static int sdma_init(struct sdma_engine *sdma)
 
 	writel_relaxed(ccb_phys, sdma->regs + SDMA_H_C0PTR);
 
-	/* Set bits of CONFIG register with given context switching mode */
-	writel_relaxed(SDMA_H_CONFIG_CSM, sdma->regs + SDMA_H_CONFIG);
-
 	/* Initializes channel's priorities */
 	sdma_set_channel_priority(&sdma->channel[0], 7);