1 files changed, 109 insertions, 22 deletions

diff --git a/drivers/dma/dw/core.c b/drivers/dma/dw/core.c
index 5f7d690e3dba..dd75f97a33b3 100644
--- a/drivers/dma/dw/core.c
+++ b/drivers/dma/dw/core.c
@@ -16,6 +16,7 @@
 #include <linux/init.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
+#include <linux/log2.h>
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/slab.h>
@@ -621,12 +622,10 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 	struct dw_desc		*prev;
 	struct dw_desc		*first;
 	u32			ctllo, ctlhi;
-	u8			m_master = dwc->dws.m_master;
-	u8			lms = DWC_LLP_LMS(m_master);
+	u8			lms = DWC_LLP_LMS(dwc->dws.m_master);
 	dma_addr_t		reg;
 	unsigned int		reg_width;
 	unsigned int		mem_width;
-	unsigned int		data_width = dw->pdata->data_width[m_master];
 	unsigned int		i;
 	struct scatterlist	*sg;
 	size_t			total_len = 0;
@@ -660,7 +659,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 			mem = sg_dma_address(sg);
 			len = sg_dma_len(sg);
 
-			mem_width = __ffs(data_width | mem | len);
+			mem_width = __ffs(sconfig->src_addr_width | mem | len);
 
 slave_sg_todev_fill_desc:
 			desc = dwc_desc_get(dwc);
@@ -720,7 +719,7 @@ slave_sg_fromdev_fill_desc:
 			lli_write(desc, sar, reg);
 			lli_write(desc, dar, mem);
 			lli_write(desc, ctlhi, ctlhi);
-			mem_width = __ffs(data_width | mem);
+			mem_width = __ffs(sconfig->dst_addr_width | mem);
 			lli_write(desc, ctllo, ctllo | DWC_CTLL_DST_WIDTH(mem_width));
 			desc->len = dlen;
 
@@ -780,20 +779,108 @@ bool dw_dma_filter(struct dma_chan *chan, void *param)
 }
 EXPORT_SYMBOL_GPL(dw_dma_filter);
 
-static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
+static int dwc_verify_maxburst(struct dma_chan *chan)
 {
 	struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
-	struct dw_dma *dw = to_dw_dma(chan->device);
 
-	memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
+	dwc->dma_sconfig.src_maxburst =
+		clamp(dwc->dma_sconfig.src_maxburst, 1U, dwc->max_burst);
+	dwc->dma_sconfig.dst_maxburst =
+		clamp(dwc->dma_sconfig.dst_maxburst, 1U, dwc->max_burst);
 
 	dwc->dma_sconfig.src_maxburst =
-		clamp(dwc->dma_sconfig.src_maxburst, 0U, dwc->max_burst);
+		rounddown_pow_of_two(dwc->dma_sconfig.src_maxburst);
 	dwc->dma_sconfig.dst_maxburst =
-		clamp(dwc->dma_sconfig.dst_maxburst, 0U, dwc->max_burst);
+		rounddown_pow_of_two(dwc->dma_sconfig.dst_maxburst);
 
-	dw->encode_maxburst(dwc, &dwc->dma_sconfig.src_maxburst);
-	dw->encode_maxburst(dwc, &dwc->dma_sconfig.dst_maxburst);
+	return 0;
+}
+
+static int dwc_verify_p_buswidth(struct dma_chan *chan)
+{
+	struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
+	struct dw_dma *dw = to_dw_dma(chan->device);
+	u32 reg_width, max_width;
+
+	if (dwc->dma_sconfig.direction == DMA_MEM_TO_DEV)
+		reg_width = dwc->dma_sconfig.dst_addr_width;
+	else if (dwc->dma_sconfig.direction == DMA_DEV_TO_MEM)
+		reg_width = dwc->dma_sconfig.src_addr_width;
+	else /* DMA_MEM_TO_MEM */
+		return 0;
+
+	max_width = dw->pdata->data_width[dwc->dws.p_master];
+
+	/* Fall-back to 1-byte transfer width if undefined */
+	if (reg_width == DMA_SLAVE_BUSWIDTH_UNDEFINED)
+		reg_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	else if (!is_power_of_2(reg_width) || reg_width > max_width)
+		return -EINVAL;
+	else /* bus width is valid */
+		return 0;
+
+	/* Update undefined addr width value */
+	if (dwc->dma_sconfig.direction == DMA_MEM_TO_DEV)
+		dwc->dma_sconfig.dst_addr_width = reg_width;
+	else /* DMA_DEV_TO_MEM */
+		dwc->dma_sconfig.src_addr_width = reg_width;
+
+	return 0;
+}
+
+static int dwc_verify_m_buswidth(struct dma_chan *chan)
+{
+	struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
+	struct dw_dma *dw = to_dw_dma(chan->device);
+	u32 reg_width, reg_burst, mem_width;
+
+	mem_width = dw->pdata->data_width[dwc->dws.m_master];
+
+	/*
+	 * It's possible to have a data portion locked in the DMA FIFO in case
+	 * of the channel suspension. Subsequent channel disabling will cause
+	 * that data silent loss. In order to prevent that maintain the src and
+	 * dst transfer widths coherency by means of the relation:
+	 * (CTLx.SRC_TR_WIDTH * CTLx.SRC_MSIZE >= CTLx.DST_TR_WIDTH)
+	 * Look for the details in the commit message that brings this change.
+	 *
+	 * Note the DMA configs utilized in the calculations below must have
+	 * been verified to have correct values by this method call.
+	 */
+	if (dwc->dma_sconfig.direction == DMA_MEM_TO_DEV) {
+		reg_width = dwc->dma_sconfig.dst_addr_width;
+		if (mem_width < reg_width)
+			return -EINVAL;
+
+		dwc->dma_sconfig.src_addr_width = mem_width;
+	} else if (dwc->dma_sconfig.direction == DMA_DEV_TO_MEM) {
+		reg_width = dwc->dma_sconfig.src_addr_width;
+		reg_burst = dwc->dma_sconfig.src_maxburst;
+
+		dwc->dma_sconfig.dst_addr_width = min(mem_width, reg_width * reg_burst);
+	}
+
+	return 0;
+}
+
+static int dwc_config(struct dma_chan *chan, struct dma_slave_config *sconfig)
+{
+	struct dw_dma_chan *dwc = to_dw_dma_chan(chan);
+	int ret;
+
+	memcpy(&dwc->dma_sconfig, sconfig, sizeof(*sconfig));
+
+	ret = dwc_verify_maxburst(chan);
+	if (ret)
+		return ret;
+
+	ret = dwc_verify_p_buswidth(chan);
+	if (ret)
+		return ret;
+
+	ret = dwc_verify_m_buswidth(chan);
+	if (ret)
+		return ret;
 
 	return 0;
 }
@@ -1068,7 +1155,7 @@ int do_dma_probe(struct dw_dma_chip *chip)
 	bool			autocfg = false;
 	unsigned int		dw_params;
 	unsigned int		i;
-	int			err;
+	int			ret;
 
 	dw->pdata = devm_kzalloc(chip->dev, sizeof(*dw->pdata), GFP_KERNEL);
 	if (!dw->pdata)
@@ -1084,7 +1171,7 @@ int do_dma_probe(struct dw_dma_chip *chip)
 
 		autocfg = dw_params >> DW_PARAMS_EN & 1;
 		if (!autocfg) {
-			err = -EINVAL;
+			ret = -EINVAL;
 			goto err_pdata;
 		}
 
@@ -1104,7 +1191,7 @@ int do_dma_probe(struct dw_dma_chip *chip)
 		pdata->chan_allocation_order = CHAN_ALLOCATION_ASCENDING;
 		pdata->chan_priority = CHAN_PRIORITY_ASCENDING;
 	} else if (chip->pdata->nr_channels > DW_DMA_MAX_NR_CHANNELS) {
-		err = -EINVAL;
+		ret = -EINVAL;
 		goto err_pdata;
 	} else {
 		memcpy(dw->pdata, chip->pdata, sizeof(*dw->pdata));
@@ -1116,7 +1203,7 @@ int do_dma_probe(struct dw_dma_chip *chip)
 	dw->chan = devm_kcalloc(chip->dev, pdata->nr_channels, sizeof(*dw->chan),
 				GFP_KERNEL);
 	if (!dw->chan) {
-		err = -ENOMEM;
+		ret = -ENOMEM;
 		goto err_pdata;
 	}
 
@@ -1134,15 +1221,15 @@ int do_dma_probe(struct dw_dma_chip *chip)
 					 sizeof(struct dw_desc), 4, 0);
 	if (!dw->desc_pool) {
 		dev_err(chip->dev, "No memory for descriptors dma pool\n");
-		err = -ENOMEM;
+		ret = -ENOMEM;
 		goto err_pdata;
 	}
 
 	tasklet_setup(&dw->tasklet, dw_dma_tasklet);
 
-	err = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED,
+	ret = request_irq(chip->irq, dw_dma_interrupt, IRQF_SHARED,
 			  dw->name, dw);
-	if (err)
+	if (ret)
 		goto err_pdata;
 
 	INIT_LIST_HEAD(&dw->dma.channels);
@@ -1254,8 +1341,8 @@ int do_dma_probe(struct dw_dma_chip *chip)
 	 */
 	dma_set_max_seg_size(dw->dma.dev, dw->chan[0].block_size);
 
-	err = dma_async_device_register(&dw->dma);
-	if (err)
+	ret = dma_async_device_register(&dw->dma);
+	if (ret)
 		goto err_dma_register;
 
 	dev_info(chip->dev, "DesignWare DMA Controller, %d channels\n",
@@ -1269,7 +1356,7 @@ err_dma_register:
 	free_irq(chip->irq, dw);
 err_pdata:
 	pm_runtime_put_sync_suspend(chip->dev);
-	return err;
+	return ret;
 }
 
 int do_dma_remove(struct dw_dma_chip *chip)