Merge branch 'topic/core' into for-linus

drivers/dma/dmaengine.c

@@ -482,7 +482,8 @@ int dma_get_slave_caps(struct dma_chan *chan, struct dma_slave_caps *caps)
 	device = chan->device;
 
 	/* check if the channel supports slave transactions */
-	if (!test_bit(DMA_SLAVE, device->cap_mask.bits))
+	if (!(test_bit(DMA_SLAVE, device->cap_mask.bits) ||
+	      test_bit(DMA_CYCLIC, device->cap_mask.bits)))
 		return -ENXIO;
 
 	/*
@@ -865,12 +866,12 @@ static bool device_has_all_tx_types(struct dma_device *device)
 		return false;
 	#endif
 
-	#if defined(CONFIG_ASYNC_MEMCPY) || defined(CONFIG_ASYNC_MEMCPY_MODULE)
+	#if IS_ENABLED(CONFIG_ASYNC_MEMCPY)
 	if (!dma_has_cap(DMA_MEMCPY, device->cap_mask))
 		return false;
 	#endif
 
-	#if defined(CONFIG_ASYNC_XOR) || defined(CONFIG_ASYNC_XOR_MODULE)
+	#if IS_ENABLED(CONFIG_ASYNC_XOR)
 	if (!dma_has_cap(DMA_XOR, device->cap_mask))
 		return false;
 
@@ -880,7 +881,7 @@ static bool device_has_all_tx_types(struct dma_device *device)
 	#endif
 	#endif
 
-	#if defined(CONFIG_ASYNC_PQ) || defined(CONFIG_ASYNC_PQ_MODULE)
+	#if IS_ENABLED(CONFIG_ASYNC_PQ)
 	if (!dma_has_cap(DMA_PQ, device->cap_mask))
 		return false;
 

drivers/dma/of-dma.c

@@ -240,8 +240,9 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
 	struct of_phandle_args	dma_spec;
 	struct of_dma		*ofdma;
 	struct dma_chan		*chan;
-	int			count, i;
+	int			count, i, start;
 	int			ret_no_channel = -ENODEV;
+	static atomic_t		last_index;
 
 	if (!np || !name) {
 		pr_err("%s: not enough information provided\n", __func__);
@@ -259,8 +260,15 @@ struct dma_chan *of_dma_request_slave_channel(struct device_node *np,
 		return ERR_PTR(-ENODEV);
 	}
 
+	/*
+	 * approximate an average distribution across multiple
+	 * entries with the same name
+	 */
+	start = atomic_inc_return(&last_index);
 	for (i = 0; i < count; i++) {
-		if (of_dma_match_channel(np, name, i, &dma_spec))
+		if (of_dma_match_channel(np, name,
+					 (i + start) % count,
+					 &dma_spec))
 			continue;
 
 		mutex_lock(&of_dma_lock);

include/linux/dmaengine.h

@@ -804,6 +804,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_slave_single(
 	sg_dma_address(&sg) = buf;
 	sg_dma_len(&sg) = len;
 
+	if (!chan || !chan->device || !chan->device->device_prep_slave_sg)
+		return NULL;
+
 	return chan->device->device_prep_slave_sg(chan, &sg, 1,
 						  dir, flags, NULL);
 }
@@ -812,6 +815,9 @@ 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)
 {
+	if (!chan || !chan->device || !chan->device->device_prep_slave_sg)
+		return NULL;
+
 	return chan->device->device_prep_slave_sg(chan, sgl, sg_len,
 						  dir, flags, NULL);
 }
@@ -823,6 +829,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_rio_sg(
 	enum dma_transfer_direction dir, unsigned long flags,
 	struct rio_dma_ext *rio_ext)
 {
+	if (!chan || !chan->device || !chan->device->device_prep_slave_sg)
+		return NULL;
+
 	return chan->device->device_prep_slave_sg(chan, sgl, sg_len,
 						  dir, flags, rio_ext);
 }
@@ -833,6 +842,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_cyclic(
 		size_t period_len, enum dma_transfer_direction dir,
 		unsigned long flags)
 {
+	if (!chan || !chan->device || !chan->device->device_prep_dma_cyclic)
+		return NULL;
+
 	return chan->device->device_prep_dma_cyclic(chan, buf_addr, buf_len,
 						period_len, dir, flags);
 }
@@ -841,6 +853,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_interleaved_dma(
 		struct dma_chan *chan, struct dma_interleaved_template *xt,
 		unsigned long flags)
 {
+	if (!chan || !chan->device || !chan->device->device_prep_interleaved_dma)
+		return NULL;
+
 	return chan->device->device_prep_interleaved_dma(chan, xt, flags);
 }
 
@@ -848,7 +863,7 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_memset(
 		struct dma_chan *chan, dma_addr_t dest, int value, size_t len,
 		unsigned long flags)
 {
-	if (!chan || !chan->device)
+	if (!chan || !chan->device || !chan->device->device_prep_dma_memset)
 		return NULL;
 
 	return chan->device->device_prep_dma_memset(chan, dest, value,
@@ -861,6 +876,9 @@ static inline struct dma_async_tx_descriptor *dmaengine_prep_dma_sg(
 		struct scatterlist *src_sg, unsigned int src_nents,
 		unsigned long flags)
 {
+	if (!chan || !chan->device || !chan->device->device_prep_dma_sg)
+		return NULL;
+
 	return chan->device->device_prep_dma_sg(chan, dst_sg, dst_nents,
 			src_sg, src_nents, flags);
 }