1 files changed, 52 insertions, 69 deletions

diff --git a/drivers/dma/at_hdmac.c b/drivers/dma/at_hdmac.c
index 672c73b4a2d4..73a20780744b 100644
--- a/drivers/dma/at_hdmac.c
+++ b/drivers/dma/at_hdmac.c
@@ -146,17 +146,8 @@ static struct at_desc *atc_desc_get(struct at_dma_chan *atchan)
 		"scanned %u descriptors on freelist\n", i);
 
 	/* no more descriptor available in initial pool: create one more */
-	if (!ret) {
-		ret = atc_alloc_descriptor(&atchan->chan_common, GFP_ATOMIC);
-		if (ret) {
-			spin_lock_irqsave(&atchan->lock, flags);
-			atchan->descs_allocated++;
-			spin_unlock_irqrestore(&atchan->lock, flags);
-		} else {
-			dev_err(chan2dev(&atchan->chan_common),
-					"not enough descriptors available\n");
-		}
-	}
+	if (!ret)
+		ret = atc_alloc_descriptor(&atchan->chan_common, GFP_NOWAIT);
 
 	return ret;
 }
@@ -435,17 +426,19 @@ static int atc_get_bytes_left(struct dma_chan *chan, dma_cookie_t cookie)
  * atc_chain_complete - finish work for one transaction chain
  * @atchan: channel we work on
  * @desc: descriptor at the head of the chain we want do complete
- *
- * Called with atchan->lock held and bh disabled */
+ */
 static void
 atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
 {
 	struct dma_async_tx_descriptor	*txd = &desc->txd;
 	struct at_dma			*atdma = to_at_dma(atchan->chan_common.device);
+	unsigned long flags;
 
 	dev_vdbg(chan2dev(&atchan->chan_common),
 		"descriptor %u complete\n", txd->cookie);
 
+	spin_lock_irqsave(&atchan->lock, flags);
+
 	/* mark the descriptor as complete for non cyclic cases only */
 	if (!atc_chan_is_cyclic(atchan))
 		dma_cookie_complete(txd);
@@ -462,16 +455,13 @@ atc_chain_complete(struct at_dma_chan *atchan, struct at_desc *desc)
 	/* move myself to free_list */
 	list_move(&desc->desc_node, &atchan->free_list);
 
+	spin_unlock_irqrestore(&atchan->lock, flags);
+
 	dma_descriptor_unmap(txd);
 	/* for cyclic transfers,
 	 * no need to replay callback function while stopping */
-	if (!atc_chan_is_cyclic(atchan)) {
-		/*
-		 * The API requires that no submissions are done from a
-		 * callback, so we don't need to drop the lock here
-		 */
+	if (!atc_chan_is_cyclic(atchan))
 		dmaengine_desc_get_callback_invoke(txd, NULL);
-	}
 
 	dma_run_dependencies(txd);
 }
@@ -489,9 +479,12 @@ static void atc_complete_all(struct at_dma_chan *atchan)
 {
 	struct at_desc *desc, *_desc;
 	LIST_HEAD(list);
+	unsigned long flags;
 
 	dev_vdbg(chan2dev(&atchan->chan_common), "complete all\n");
 
+	spin_lock_irqsave(&atchan->lock, flags);
+
 	/*
 	 * Submit queued descriptors ASAP, i.e. before we go through
 	 * the completed ones.
@@ -503,6 +496,8 @@ static void atc_complete_all(struct at_dma_chan *atchan)
 	/* empty queue list by moving descriptors (if any) to active_list */
 	list_splice_init(&atchan->queue, &atchan->active_list);
 
+	spin_unlock_irqrestore(&atchan->lock, flags);
+
 	list_for_each_entry_safe(desc, _desc, &list, desc_node)
 		atc_chain_complete(atchan, desc);
 }
@@ -510,38 +505,44 @@ static void atc_complete_all(struct at_dma_chan *atchan)
 /**
  * atc_advance_work - at the end of a transaction, move forward
  * @atchan: channel where the transaction ended
- *
- * Called with atchan->lock held and bh disabled
  */
 static void atc_advance_work(struct at_dma_chan *atchan)
 {
+	unsigned long flags;
+	int ret;
+
 	dev_vdbg(chan2dev(&atchan->chan_common), "advance_work\n");
 
-	if (atc_chan_is_enabled(atchan))
+	spin_lock_irqsave(&atchan->lock, flags);
+	ret = atc_chan_is_enabled(atchan);
+	spin_unlock_irqrestore(&atchan->lock, flags);
+	if (ret)
 		return;
 
 	if (list_empty(&atchan->active_list) ||
-	    list_is_singular(&atchan->active_list)) {
-		atc_complete_all(atchan);
-	} else {
-		atc_chain_complete(atchan, atc_first_active(atchan));
-		/* advance work */
-		atc_dostart(atchan, atc_first_active(atchan));
-	}
+	    list_is_singular(&atchan->active_list))
+		return atc_complete_all(atchan);
+
+	atc_chain_complete(atchan, atc_first_active(atchan));
+
+	/* advance work */
+	spin_lock_irqsave(&atchan->lock, flags);
+	atc_dostart(atchan, atc_first_active(atchan));
+	spin_unlock_irqrestore(&atchan->lock, flags);
 }
 
 
 /**
  * atc_handle_error - handle errors reported by DMA controller
  * @atchan: channel where error occurs
- *
- * Called with atchan->lock held and bh disabled
  */
 static void atc_handle_error(struct at_dma_chan *atchan)
 {
 	struct at_desc *bad_desc;
 	struct at_desc *child;
+	unsigned long flags;
 
+	spin_lock_irqsave(&atchan->lock, flags);
 	/*
 	 * The descriptor currently at the head of the active list is
 	 * broked. Since we don't have any way to report errors, we'll
@@ -573,6 +574,8 @@ static void atc_handle_error(struct at_dma_chan *atchan)
 	list_for_each_entry(child, &bad_desc->tx_list, desc_node)
 		atc_dump_lli(atchan, &child->lli);
 
+	spin_unlock_irqrestore(&atchan->lock, flags);
+
 	/* Pretend the descriptor completed successfully */
 	atc_chain_complete(atchan, bad_desc);
 }
@@ -580,8 +583,6 @@ static void atc_handle_error(struct at_dma_chan *atchan)
 /**
  * atc_handle_cyclic - at the end of a period, run callback function
  * @atchan: channel used for cyclic operations
- *
- * Called with atchan->lock held and bh disabled
  */
 static void atc_handle_cyclic(struct at_dma_chan *atchan)
 {
@@ -600,17 +601,14 @@ static void atc_handle_cyclic(struct at_dma_chan *atchan)
 static void atc_tasklet(unsigned long data)
 {
 	struct at_dma_chan *atchan = (struct at_dma_chan *)data;
-	unsigned long flags;
 
-	spin_lock_irqsave(&atchan->lock, flags);
 	if (test_and_clear_bit(ATC_IS_ERROR, &atchan->status))
-		atc_handle_error(atchan);
-	else if (atc_chan_is_cyclic(atchan))
-		atc_handle_cyclic(atchan);
-	else
-		atc_advance_work(atchan);
+		return atc_handle_error(atchan);
 
-	spin_unlock_irqrestore(&atchan->lock, flags);
+	if (atc_chan_is_cyclic(atchan))
+		return atc_handle_cyclic(atchan);
+
+	atc_advance_work(atchan);
 }
 
 static irqreturn_t at_dma_interrupt(int irq, void *dev_id)
@@ -940,7 +938,7 @@ atc_prep_dma_memset(struct dma_chan *chan, dma_addr_t dest, int value,
 		return NULL;
 	}
 
-	vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr);
+	vaddr = dma_pool_alloc(atdma->memset_pool, GFP_NOWAIT, &paddr);
 	if (!vaddr) {
 		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
 			__func__);
@@ -998,7 +996,7 @@ atc_prep_dma_memset_sg(struct dma_chan *chan,
 		return NULL;
 	}
 
-	vaddr = dma_pool_alloc(atdma->memset_pool, GFP_ATOMIC, &paddr);
+	vaddr = dma_pool_alloc(atdma->memset_pool, GFP_NOWAIT, &paddr);
 	if (!vaddr) {
 		dev_err(chan2dev(chan), "%s: couldn't allocate buffer\n",
 			__func__);
@@ -1446,6 +1444,8 @@ static int atc_terminate_all(struct dma_chan *chan)
 	list_splice_init(&atchan->queue, &list);
 	list_splice_init(&atchan->active_list, &list);
 
+	spin_unlock_irqrestore(&atchan->lock, flags);
+
 	/* Flush all pending and queued descriptors */
 	list_for_each_entry_safe(desc, _desc, &list, desc_node)
 		atc_chain_complete(atchan, desc);
@@ -1454,8 +1454,6 @@ static int atc_terminate_all(struct dma_chan *chan)
 	/* if channel dedicated to cyclic operations, free it */
 	clear_bit(ATC_IS_CYCLIC, &atchan->status);
 
-	spin_unlock_irqrestore(&atchan->lock, flags);
-
 	return 0;
 }
 
@@ -1516,7 +1514,6 @@ atc_tx_status(struct dma_chan *chan,
 static void atc_issue_pending(struct dma_chan *chan)
 {
 	struct at_dma_chan	*atchan = to_at_dma_chan(chan);
-	unsigned long		flags;
 
 	dev_vdbg(chan2dev(chan), "issue_pending\n");
 
@@ -1524,15 +1521,12 @@ static void atc_issue_pending(struct dma_chan *chan)
 	if (atc_chan_is_cyclic(atchan))
 		return;
 
-	spin_lock_irqsave(&atchan->lock, flags);
 	atc_advance_work(atchan);
-	spin_unlock_irqrestore(&atchan->lock, flags);
 }
 
 /**
  * atc_alloc_chan_resources - allocate resources for DMA channel
  * @chan: allocate descriptor resources for this channel
- * @client: current client requesting the channel be ready for requests
  *
  * return - the number of allocated descriptors
  */
@@ -1542,10 +1536,8 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
 	struct at_dma		*atdma = to_at_dma(chan->device);
 	struct at_desc		*desc;
 	struct at_dma_slave	*atslave;
-	unsigned long		flags;
 	int			i;
 	u32			cfg;
-	LIST_HEAD(tmp_list);
 
 	dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
 
@@ -1555,6 +1547,11 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
 		return -EIO;
 	}
 
+	if (!list_empty(&atchan->free_list)) {
+		dev_dbg(chan2dev(chan), "can't allocate channel resources (channel not freed from a previous use)\n");
+		return -EIO;
+	}
+
 	cfg = ATC_DEFAULT_CFG;
 
 	atslave = chan->private;
@@ -1570,11 +1567,6 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
 			cfg = atslave->cfg;
 	}
 
-	/* have we already been set up?
-	 * reconfigure channel but no need to reallocate descriptors */
-	if (!list_empty(&atchan->free_list))
-		return atchan->descs_allocated;
-
 	/* Allocate initial pool of descriptors */
 	for (i = 0; i < init_nr_desc_per_channel; i++) {
 		desc = atc_alloc_descriptor(chan, GFP_KERNEL);
@@ -1583,23 +1575,18 @@ static int atc_alloc_chan_resources(struct dma_chan *chan)
 				"Only %d initial descriptors\n", i);
 			break;
 		}
-		list_add_tail(&desc->desc_node, &tmp_list);
+		list_add_tail(&desc->desc_node, &atchan->free_list);
 	}
 
-	spin_lock_irqsave(&atchan->lock, flags);
-	atchan->descs_allocated = i;
-	list_splice(&tmp_list, &atchan->free_list);
 	dma_cookie_init(chan);
-	spin_unlock_irqrestore(&atchan->lock, flags);
 
 	/* channel parameters */
 	channel_writel(atchan, CFG, cfg);
 
 	dev_dbg(chan2dev(chan),
-		"alloc_chan_resources: allocated %d descriptors\n",
-		atchan->descs_allocated);
+		"alloc_chan_resources: allocated %d descriptors\n", i);
 
-	return atchan->descs_allocated;
+	return i;
 }
 
 /**
@@ -1613,9 +1600,6 @@ static void atc_free_chan_resources(struct dma_chan *chan)
 	struct at_desc		*desc, *_desc;
 	LIST_HEAD(list);
 
-	dev_dbg(chan2dev(chan), "free_chan_resources: (descs allocated=%u)\n",
-		atchan->descs_allocated);
-
 	/* ASSERT:  channel is idle */
 	BUG_ON(!list_empty(&atchan->active_list));
 	BUG_ON(!list_empty(&atchan->queue));
@@ -1628,7 +1612,6 @@ static void atc_free_chan_resources(struct dma_chan *chan)
 		dma_pool_free(atdma->dma_desc_pool, desc, desc->txd.phys);
 	}
 	list_splice_init(&atchan->free_list, &list);
-	atchan->descs_allocated = 0;
 	atchan->status = 0;
 
 	/*
@@ -1671,7 +1654,7 @@ static struct dma_chan *at_dma_xlate(struct of_phandle_args *dma_spec,
 	dma_cap_zero(mask);
 	dma_cap_set(DMA_SLAVE, mask);
 
-	atslave = kzalloc(sizeof(*atslave), GFP_KERNEL);
+	atslave = kmalloc(sizeof(*atslave), GFP_KERNEL);
 	if (!atslave)
 		return NULL;