MERGE-via-pending-tracking-hist-MERGE-via-stable-tracking-MERGE-via-mokopatches-tracking-fix-stray-endmenu-patch-1232632040-1232632141

pending-tracking-hist top was MERGE-via-stable-tracking-MERGE-via-mokopatches-tracking-fix-stray-endmenu-patch-1232632040-1232632141 / fdf777a63bcb59e0dfd78bfe2c6242e01f6d4eb9 ... parent commitmessage:
From: merge <null@invalid>
MERGE-via-stable-tracking-hist-MERGE-via-mokopatches-tracking-fix-stray-endmenu-patch-1232632040

stable-tracking-hist top was MERGE-via-mokopatches-tracking-fix-stray-endmenu-patch-1232632040 / 90463bfd2d5a3c8b52f6e6d71024a00e052b0ced ... parent commitmessage:
From: merge <null@invalid>
MERGE-via-mokopatches-tracking-hist-fix-stray-endmenu-patch

mokopatches-tracking-hist top was fix-stray-endmenu-patch / 3630e0be570de8057e7f8d2fe501ed353cdf34e6 ... parent commitmessage:
From: Andy Green <andy@openmoko.com>
fix-stray-endmenu.patch

Signed-off-by: Andy Green <andy@openmoko.com>

10 files changed, 782 insertions, 482 deletions

diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig
index 904e57558bb..e34b0642081 100644
--- a/drivers/dma/Kconfig
+++ b/drivers/dma/Kconfig
@@ -33,7 +33,6 @@ config INTEL_IOATDMA
 config INTEL_IOP_ADMA
 	tristate "Intel IOP ADMA support"
 	depends on ARCH_IOP32X || ARCH_IOP33X || ARCH_IOP13XX
-	select ASYNC_CORE
 	select DMA_ENGINE
 	help
 	  Enable support for the Intel(R) IOP Series RAID engines.
@@ -59,7 +58,6 @@ config FSL_DMA
 config MV_XOR
 	bool "Marvell XOR engine support"
 	depends on PLAT_ORION
-	select ASYNC_CORE
 	select DMA_ENGINE
 	---help---
 	  Enable support for the Marvell XOR engine.
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index dc003a3a787..403dbe78112 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -31,32 +31,18 @@
  *
  * LOCKING:
  *
- * The subsystem keeps two global lists, dma_device_list and dma_client_list.
- * Both of these are protected by a mutex, dma_list_mutex.
+ * The subsystem keeps a global list of dma_device structs it is protected by a
+ * mutex, dma_list_mutex.
+ *
+ * A subsystem can get access to a channel by calling dmaengine_get() followed
+ * by dma_find_channel(), or if it has need for an exclusive channel it can call
+ * dma_request_channel().  Once a channel is allocated a reference is taken
+ * against its corresponding driver to disable removal.
  *
  * Each device has a channels list, which runs unlocked but is never modified
  * once the device is registered, it's just setup by the driver.
  *
- * Each client is responsible for keeping track of the channels it uses.  See
- * the definition of dma_event_callback in dmaengine.h.
- *
- * Each device has a kref, which is initialized to 1 when the device is
- * registered. A kref_get is done for each device registered.  When the
- * device is released, the corresponding kref_put is done in the release
- * method. Every time one of the device's channels is allocated to a client,
- * a kref_get occurs.  When the channel is freed, the corresponding kref_put
- * happens. The device's release function does a completion, so
- * unregister_device does a remove event, device_unregister, a kref_put
- * for the first reference, then waits on the completion for all other
- * references to finish.
- *
- * Each channel has an open-coded implementation of Rusty Russell's "bigref,"
- * with a kref and a per_cpu local_t.  A dma_chan_get is called when a client
- * signals that it wants to use a channel, and dma_chan_put is called when
- * a channel is removed or a client using it is unregistered.  A client can
- * take extra references per outstanding transaction, as is the case with
- * the NET DMA client.  The release function does a kref_put on the device.
- *	-ChrisL, DanW
+ * See Documentation/dmaengine.txt for more details
  */
 
 #include <linux/init.h>
@@ -70,54 +56,85 @@
 #include <linux/rcupdate.h>
 #include <linux/mutex.h>
 #include <linux/jiffies.h>
+#include <linux/rculist.h>
+#include <linux/idr.h>
 
 static DEFINE_MUTEX(dma_list_mutex);
 static LIST_HEAD(dma_device_list);
-static LIST_HEAD(dma_client_list);
+static long dmaengine_ref_count;
+static struct idr dma_idr;
 
 /* --- sysfs implementation --- */
 
+/**
+ * dev_to_dma_chan - convert a device pointer to the its sysfs container object
+ * @dev - device node
+ *
+ * Must be called under dma_list_mutex
+ */
+static struct dma_chan *dev_to_dma_chan(struct device *dev)
+{
+	struct dma_chan_dev *chan_dev;
+
+	chan_dev = container_of(dev, typeof(*chan_dev), device);
+	return chan_dev->chan;
+}
+
 static ssize_t show_memcpy_count(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	struct dma_chan *chan = to_dma_chan(dev);
+	struct dma_chan *chan;
 	unsigned long count = 0;
 	int i;
+	int err;
 
-	for_each_possible_cpu(i)
-		count += per_cpu_ptr(chan->local, i)->memcpy_count;
+	mutex_lock(&dma_list_mutex);
+	chan = dev_to_dma_chan(dev);
+	if (chan) {
+		for_each_possible_cpu(i)
+			count += per_cpu_ptr(chan->local, i)->memcpy_count;
+		err = sprintf(buf, "%lu\n", count);
+	} else
+		err = -ENODEV;
+	mutex_unlock(&dma_list_mutex);
 
-	return sprintf(buf, "%lu\n", count);
+	return err;
 }
 
 static ssize_t show_bytes_transferred(struct device *dev, struct device_attribute *attr,
 				      char *buf)
 {
-	struct dma_chan *chan = to_dma_chan(dev);
+	struct dma_chan *chan;
 	unsigned long count = 0;
 	int i;
+	int err;
 
-	for_each_possible_cpu(i)
-		count += per_cpu_ptr(chan->local, i)->bytes_transferred;
+	mutex_lock(&dma_list_mutex);
+	chan = dev_to_dma_chan(dev);
+	if (chan) {
+		for_each_possible_cpu(i)
+			count += per_cpu_ptr(chan->local, i)->bytes_transferred;
+		err = sprintf(buf, "%lu\n", count);
+	} else
+		err = -ENODEV;
+	mutex_unlock(&dma_list_mutex);
 
-	return sprintf(buf, "%lu\n", count);
+	return err;
 }
 
 static ssize_t show_in_use(struct device *dev, struct device_attribute *attr, char *buf)
 {
-	struct dma_chan *chan = to_dma_chan(dev);
-	int in_use = 0;
-
-	if (unlikely(chan->slow_ref) &&
-		atomic_read(&chan->refcount.refcount) > 1)
-		in_use = 1;
-	else {
-		if (local_read(&(per_cpu_ptr(chan->local,
-			get_cpu())->refcount)) > 0)
-			in_use = 1;
-		put_cpu();
-	}
+	struct dma_chan *chan;
+	int err;
+
+	mutex_lock(&dma_list_mutex);
+	chan = dev_to_dma_chan(dev);
+	if (chan)
+		err = sprintf(buf, "%d\n", chan->client_count);
+	else
+		err = -ENODEV;
+	mutex_unlock(&dma_list_mutex);
 
-	return sprintf(buf, "%d\n", in_use);
+	return err;
 }
 
 static struct device_attribute dma_attrs[] = {
@@ -127,76 +144,110 @@ static struct device_attribute dma_attrs[] = {
 	__ATTR_NULL
 };
 
-static void dma_async_device_cleanup(struct kref *kref);
-
-static void dma_dev_release(struct device *dev)
+static void chan_dev_release(struct device *dev)
 {
-	struct dma_chan *chan = to_dma_chan(dev);
-	kref_put(&chan->device->refcount, dma_async_device_cleanup);
+	struct dma_chan_dev *chan_dev;
+
+	chan_dev = container_of(dev, typeof(*chan_dev), device);
+	if (atomic_dec_and_test(chan_dev->idr_ref)) {
+		mutex_lock(&dma_list_mutex);
+		idr_remove(&dma_idr, chan_dev->dev_id);
+		mutex_unlock(&dma_list_mutex);
+		kfree(chan_dev->idr_ref);
+	}
+	kfree(chan_dev);
 }
 
 static struct class dma_devclass = {
 	.name		= "dma",
 	.dev_attrs	= dma_attrs,
-	.dev_release	= dma_dev_release,
+	.dev_release	= chan_dev_release,
 };
 
 /* --- client and device registration --- */
 
-#define dma_chan_satisfies_mask(chan, mask) \
-	__dma_chan_satisfies_mask((chan), &(mask))
+#define dma_device_satisfies_mask(device, mask) \
+	__dma_device_satisfies_mask((device), &(mask))
 static int
-__dma_chan_satisfies_mask(struct dma_chan *chan, dma_cap_mask_t *want)
+__dma_device_satisfies_mask(struct dma_device *device, dma_cap_mask_t *want)
 {
 	dma_cap_mask_t has;
 
-	bitmap_and(has.bits, want->bits, chan->device->cap_mask.bits,
+	bitmap_and(has.bits, want->bits, device->cap_mask.bits,
 		DMA_TX_TYPE_END);
 	return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END);
 }
 
+static struct module *dma_chan_to_owner(struct dma_chan *chan)
+{
+	return chan->device->dev->driver->owner;
+}
+
 /**
- * dma_client_chan_alloc - try to allocate channels to a client
- * @client: &dma_client
+ * balance_ref_count - catch up the channel reference count
+ * @chan - channel to balance ->client_count versus dmaengine_ref_count
  *
- * Called with dma_list_mutex held.
+ * balance_ref_count must be called under dma_list_mutex
  */
-static void dma_client_chan_alloc(struct dma_client *client)
+static void balance_ref_count(struct dma_chan *chan)
 {
-	struct dma_device *device;
-	struct dma_chan *chan;
-	int desc;	/* allocated descriptor count */
-	enum dma_state_client ack;
+	struct module *owner = dma_chan_to_owner(chan);
 
-	/* Find a channel */
-	list_for_each_entry(device, &dma_device_list, global_node) {
-		/* Does the client require a specific DMA controller? */
-		if (client->slave && client->slave->dma_dev
-				&& client->slave->dma_dev != device->dev)
-			continue;
+	while (chan->client_count < dmaengine_ref_count) {
+		__module_get(owner);
+		chan->client_count++;
+	}
+}
 
-		list_for_each_entry(chan, &device->channels, device_node) {
-			if (!dma_chan_satisfies_mask(chan, client->cap_mask))
-				continue;
+/**
+ * dma_chan_get - try to grab a dma channel's parent driver module
+ * @chan - channel to grab
+ *
+ * Must be called under dma_list_mutex
+ */
+static int dma_chan_get(struct dma_chan *chan)
+{
+	int err = -ENODEV;
+	struct module *owner = dma_chan_to_owner(chan);
+
+	if (chan->client_count) {
+		__module_get(owner);
+		err = 0;
+	} else if (try_module_get(owner))
+		err = 0;
+
+	if (err == 0)
+		chan->client_count++;
+
+	/* allocate upon first client reference */
+	if (chan->client_count == 1 && err == 0) {
+		int desc_cnt = chan->device->device_alloc_chan_resources(chan);
+
+		if (desc_cnt < 0) {
+			err = desc_cnt;
+			chan->client_count = 0;
+			module_put(owner);
+		} else if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
+			balance_ref_count(chan);
+	}
 
-			desc = chan->device->device_alloc_chan_resources(
-					chan, client);
-			if (desc >= 0) {
-				ack = client->event_callback(client,
-						chan,
-						DMA_RESOURCE_AVAILABLE);
+	return err;
+}
 
-				/* we are done once this client rejects
-				 * an available resource
-				 */
-				if (ack == DMA_ACK) {
-					dma_chan_get(chan);
-					chan->client_count++;
-				} else if (ack == DMA_NAK)
-					return;
-			}
-		}
-	}
+/**
+ * dma_chan_put - drop a reference to a dma channel's parent driver module
+ * @chan - channel to release
+ *
+ * Must be called under dma_list_mutex
+ */
+static void dma_chan_put(struct dma_chan *chan)
+{
+	if (!chan->client_count)
+		return; /* this channel failed alloc_chan_resources */
+	chan->client_count--;
+	module_put(dma_chan_to_owner(chan));
+	if (chan->client_count == 0)
+		chan->device->device_free_chan_resources(chan);
 }
 
 enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
@@ -218,138 +269,342 @@ enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
 EXPORT_SYMBOL(dma_sync_wait);
 
 /**
- * dma_chan_cleanup - release a DMA channel's resources
- * @kref: kernel reference structure that contains the DMA channel device
+ * dma_cap_mask_all - enable iteration over all operation types
  */
-void dma_chan_cleanup(struct kref *kref)
+static dma_cap_mask_t dma_cap_mask_all;
+
+/**
+ * dma_chan_tbl_ent - tracks channel allocations per core/operation
+ * @chan - associated channel for this entry
+ */
+struct dma_chan_tbl_ent {
+	struct dma_chan *chan;
+};
+
+/**
+ * channel_table - percpu lookup table for memory-to-memory offload providers
+ */
+static struct dma_chan_tbl_ent *channel_table[DMA_TX_TYPE_END];
+
+static int __init dma_channel_table_init(void)
 {
-	struct dma_chan *chan = container_of(kref, struct dma_chan, refcount);
-	chan->device->device_free_chan_resources(chan);
-	kref_put(&chan->device->refcount, dma_async_device_cleanup);
+	enum dma_transaction_type cap;
+	int err = 0;
+
+	bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END);
+
+	/* 'interrupt', 'private', and 'slave' are channel capabilities,
+	 * but are not associated with an operation so they do not need
+	 * an entry in the channel_table
+	 */
+	clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits);
+	clear_bit(DMA_PRIVATE, dma_cap_mask_all.bits);
+	clear_bit(DMA_SLAVE, dma_cap_mask_all.bits);
+
+	for_each_dma_cap_mask(cap, dma_cap_mask_all) {
+		channel_table[cap] = alloc_percpu(struct dma_chan_tbl_ent);
+		if (!channel_table[cap]) {
+			err = -ENOMEM;
+			break;
+		}
+	}
+
+	if (err) {
+		pr_err("dmaengine: initialization failure\n");
+		for_each_dma_cap_mask(cap, dma_cap_mask_all)
+			if (channel_table[cap])
+				free_percpu(channel_table[cap]);
+	}
+
+	return err;
 }
-EXPORT_SYMBOL(dma_chan_cleanup);
+arch_initcall(dma_channel_table_init);
 
-static void dma_chan_free_rcu(struct rcu_head *rcu)
+/**
+ * dma_find_channel - find a channel to carry out the operation
+ * @tx_type: transaction type
+ */
+struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type)
 {
-	struct dma_chan *chan = container_of(rcu, struct dma_chan, rcu);
-	int bias = 0x7FFFFFFF;
-	int i;
-	for_each_possible_cpu(i)
-		bias -= local_read(&per_cpu_ptr(chan->local, i)->refcount);
-	atomic_sub(bias, &chan->refcount.refcount);
-	kref_put(&chan->refcount, dma_chan_cleanup);
+	struct dma_chan *chan;
+	int cpu;
+
+	WARN_ONCE(dmaengine_ref_count == 0,
+		  "client called %s without a reference", __func__);
+
+	cpu = get_cpu();
+	chan = per_cpu_ptr(channel_table[tx_type], cpu)->chan;
+	put_cpu();
+
+	return chan;
 }
+EXPORT_SYMBOL(dma_find_channel);
 
-static void dma_chan_release(struct dma_chan *chan)
+/**
+ * dma_issue_pending_all - flush all pending operations across all channels
+ */
+void dma_issue_pending_all(void)
 {
-	atomic_add(0x7FFFFFFF, &chan->refcount.refcount);
-	chan->slow_ref = 1;
-	call_rcu(&chan->rcu, dma_chan_free_rcu);
+	struct dma_device *device;
+	struct dma_chan *chan;
+
+	WARN_ONCE(dmaengine_ref_count == 0,
+		  "client called %s without a reference", __func__);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(device, &dma_device_list, global_node) {
+		if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
+			continue;
+		list_for_each_entry(chan, &device->channels, device_node)
+			if (chan->client_count)
+				device->device_issue_pending(chan);
+	}
+	rcu_read_unlock();
 }
+EXPORT_SYMBOL(dma_issue_pending_all);
 
 /**
- * dma_chans_notify_available - broadcast available channels to the clients
+ * nth_chan - returns the nth channel of the given capability
+ * @cap: capability to match
+ * @n: nth channel desired
+ *
+ * Defaults to returning the channel with the desired capability and the
+ * lowest reference count when 'n' cannot be satisfied.  Must be called
+ * under dma_list_mutex.
  */
-static void dma_clients_notify_available(void)
+static struct dma_chan *nth_chan(enum dma_transaction_type cap, int n)
 {
-	struct dma_client *client;
+	struct dma_device *device;
+	struct dma_chan *chan;
+	struct dma_chan *ret = NULL;
+	struct dma_chan *min = NULL;
 
-	mutex_lock(&dma_list_mutex);
+	list_for_each_entry(device, &dma_device_list, global_node) {
+		if (!dma_has_cap(cap, device->cap_mask) ||
+		    dma_has_cap(DMA_PRIVATE, device->cap_mask))
+			continue;
+		list_for_each_entry(chan, &device->channels, device_node) {
+			if (!chan->client_count)
+				continue;
+			if (!min)
+				min = chan;
+			else if (chan->table_count < min->table_count)
+				min = chan;
+
+			if (n-- == 0) {
+				ret = chan;
+				break; /* done */
+			}
+		}
+		if (ret)
+			break; /* done */
+	}
 
-	list_for_each_entry(client, &dma_client_list, global_node)
-		dma_client_chan_alloc(client);
+	if (!ret)
+		ret = min;
 
-	mutex_unlock(&dma_list_mutex);
+	if (ret)
+		ret->table_count++;
+
+	return ret;
 }
 
 /**
- * dma_chans_notify_available - tell the clients that a channel is going away
- * @chan: channel on its way out
+ * dma_channel_rebalance - redistribute the available channels
+ *
+ * Optimize for cpu isolation (each cpu gets a dedicated channel for an
+ * operation type) in the SMP case,  and operation isolation (avoid
+ * multi-tasking channels) in the non-SMP case.  Must be called under
+ * dma_list_mutex.
  */
-static void dma_clients_notify_removed(struct dma_chan *chan)
+static void dma_channel_rebalance(void)
 {
-	struct dma_client *client;
-	enum dma_state_client ack;
+	struct dma_chan *chan;
+	struct dma_device *device;
+	int cpu;
+	int cap;
+	int n;
 
-	mutex_lock(&dma_list_mutex);
+	/* undo the last distribution */
+	for_each_dma_cap_mask(cap, dma_cap_mask_all)
+		for_each_possible_cpu(cpu)
+			per_cpu_ptr(channel_table[cap], cpu)->chan = NULL;
 
-	list_for_each_entry(client, &dma_client_list, global_node) {
-		ack = client->event_callback(client, chan,
-				DMA_RESOURCE_REMOVED);
+	list_for_each_entry(device, &dma_device_list, global_node) {
+		if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
+			continue;
+		list_for_each_entry(chan, &device->channels, device_node)
+			chan->table_count = 0;
+	}
 
-		/* client was holding resources for this channel so
-		 * free it
-		 */
-		if (ack == DMA_ACK) {
-			dma_chan_put(chan);
-			chan->client_count--;
+	/* don't populate the channel_table if no clients are available */
+	if (!dmaengine_ref_count)
+		return;
+
+	/* redistribute available channels */
+	n = 0;
+	for_each_dma_cap_mask(cap, dma_cap_mask_all)
+		for_each_online_cpu(cpu) {
+			if (num_possible_cpus() > 1)
+				chan = nth_chan(cap, n++);
+			else
+				chan = nth_chan(cap, -1);
+
+			per_cpu_ptr(channel_table[cap], cpu)->chan = chan;
 		}
+}
+
+static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_device *dev,
+					  dma_filter_fn fn, void *fn_param)
+{
+	struct dma_chan *chan;
+
+	if (!__dma_device_satisfies_mask(dev, mask)) {
+		pr_debug("%s: wrong capabilities\n", __func__);
+		return NULL;
 	}
+	/* devices with multiple channels need special handling as we need to
+	 * ensure that all channels are either private or public.
+	 */
+	if (dev->chancnt > 1 && !dma_has_cap(DMA_PRIVATE, dev->cap_mask))
+		list_for_each_entry(chan, &dev->channels, device_node) {
+			/* some channels are already publicly allocated */
+			if (chan->client_count)
+				return NULL;
+		}
 
-	mutex_unlock(&dma_list_mutex);
+	list_for_each_entry(chan, &dev->channels, device_node) {
+		if (chan->client_count) {
+			pr_debug("%s: %s busy\n",
+				 __func__, dma_chan_name(chan));
+			continue;
+		}
+		if (fn && !fn(chan, fn_param)) {
+			pr_debug("%s: %s filter said false\n",
+				 __func__, dma_chan_name(chan));
+			continue;
+		}
+		return chan;
+	}
+
+	return NULL;
 }
 
 /**
- * dma_async_client_register - register a &dma_client
- * @client: ptr to a client structure with valid 'event_callback' and 'cap_mask'
+ * dma_request_channel - try to allocate an exclusive channel
+ * @mask: capabilities that the channel must satisfy
+ * @fn: optional callback to disposition available channels
+ * @fn_param: opaque parameter to pass to dma_filter_fn
  */
-void dma_async_client_register(struct dma_client *client)
+struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, void *fn_param)
 {
-	/* validate client data */
-	BUG_ON(dma_has_cap(DMA_SLAVE, client->cap_mask) &&
-		!client->slave);
+	struct dma_device *device, *_d;
+	struct dma_chan *chan = NULL;
+	int err;
 
+	/* Find a channel */
 	mutex_lock(&dma_list_mutex);
-	list_add_tail(&client->global_node, &dma_client_list);
+	list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
+		chan = private_candidate(mask, device, fn, fn_param);
+		if (chan) {
+			/* Found a suitable channel, try to grab, prep, and
+			 * return it.  We first set DMA_PRIVATE to disable
+			 * balance_ref_count as this channel will not be
+			 * published in the general-purpose allocator
+			 */
+			dma_cap_set(DMA_PRIVATE, device->cap_mask);
+			err = dma_chan_get(chan);
+
+			if (err == -ENODEV) {
+				pr_debug("%s: %s module removed\n", __func__,
+					 dma_chan_name(chan));
+				list_del_rcu(&device->global_node);
+			} else if (err)
+				pr_err("dmaengine: failed to get %s: (%d)\n",
+				       dma_chan_name(chan), err);
+			else
+				break;
+			chan = NULL;
+		}
+	}
+	mutex_unlock(&dma_list_mutex);
+
+	pr_debug("%s: %s (%s)\n", __func__, chan ? "success" : "fail",
+		 chan ? dma_chan_name(chan) : NULL);
+
+	return chan;
+}
+EXPORT_SYMBOL_GPL(__dma_request_channel);
+
+void dma_release_channel(struct dma_chan *chan)
+{
+	mutex_lock(&dma_list_mutex);
+	WARN_ONCE(chan->client_count != 1,
+		  "chan reference count %d != 1\n", chan->client_count);
+	dma_chan_put(chan);
 	mutex_unlock(&dma_list_mutex);
 }
-EXPORT_SYMBOL(dma_async_client_register);
+EXPORT_SYMBOL_GPL(dma_release_channel);
 
 /**
- * dma_async_client_unregister - unregister a client and free the &dma_client
- * @client: &dma_client to free
- *
- * Force frees any allocated DMA channels, frees the &dma_client memory
+ * dmaengine_get - register interest in dma_channels
  */
-void dma_async_client_unregister(struct dma_client *client)
+void dmaengine_get(void)
 {
-	struct dma_device *device;
+	struct dma_device *device, *_d;
 	struct dma_chan *chan;
-	enum dma_state_client ack;
-
-	if (!client)
-		return;
+	int err;
 
 	mutex_lock(&dma_list_mutex);
-	/* free all channels the client is holding */
-	list_for_each_entry(device, &dma_device_list, global_node)
-		list_for_each_entry(chan, &device->channels, device_node) {
-			ack = client->event_callback(client, chan,
-				DMA_RESOURCE_REMOVED);
+	dmaengine_ref_count++;
 
-			if (ack == DMA_ACK) {
-				dma_chan_put(chan);
-				chan->client_count--;
-			}
+	/* try to grab channels */
+	list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
+		if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
+			continue;
+		list_for_each_entry(chan, &device->channels, device_node) {
+			err = dma_chan_get(chan);
+			if (err == -ENODEV) {
+				/* module removed before we could use it */
+				list_del_rcu(&device->global_node);
+				break;
+			} else if (err)
+				pr_err("dmaengine: failed to get %s: (%d)\n",
+				       dma_chan_name(chan), err);
 		}
+	}
 
-	list_del(&client->global_node);
+	/* if this is the first reference and there were channels
+	 * waiting we need to rebalance to get those channels
+	 * incorporated into the channel table
+	 */
+	if (dmaengine_ref_count == 1)
+		dma_channel_rebalance();
 	mutex_unlock(&dma_list_mutex);
 }
-EXPORT_SYMBOL(dma_async_client_unregister);
+EXPORT_SYMBOL(dmaengine_get);
 
 /**
- * dma_async_client_chan_request - send all available channels to the
- * client that satisfy the capability mask
- * @client - requester
+ * dmaengine_put - let dma drivers be removed when ref_count == 0
  */
-void dma_async_client_chan_request(struct dma_client *client)
+void dmaengine_put(void)
 {
+	struct dma_device *device;
+	struct dma_chan *chan;
+
 	mutex_lock(&dma_list_mutex);
-	dma_client_chan_alloc(client);
+	dmaengine_ref_count--;
+	BUG_ON(dmaengine_ref_count < 0);
+	/* drop channel references */
+	list_for_each_entry(device, &dma_device_list, global_node) {
+		if (dma_has_cap(DMA_PRIVATE, device->cap_mask))
+			continue;
+		list_for_each_entry(chan, &device->channels, device_node)
+			dma_chan_put(chan);
+	}
 	mutex_unlock(&dma_list_mutex);
 }
-EXPORT_SYMBOL(dma_async_client_chan_request);
+EXPORT_SYMBOL(dmaengine_put);
 
 /**
  * dma_async_device_register - registers DMA devices found
@@ -357,9 +612,9 @@ EXPORT_SYMBOL(dma_async_client_chan_request);
  */
 int dma_async_device_register(struct dma_device *device)
 {
-	static int id;
 	int chancnt = 0, rc;
 	struct dma_chan* chan;
+	atomic_t *idr_ref;
 
 	if (!device)
 		return -ENODEV;
@@ -386,54 +641,83 @@ int dma_async_device_register(struct dma_device *device)
 	BUG_ON(!device->device_issue_pending);
 	BUG_ON(!device->dev);
 
-	init_completion(&device->done);
-	kref_init(&device->refcount);
-	device->dev_id = id++;
+	idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL);
+	if (!idr_ref)
+		return -ENOMEM;
+	atomic_set(idr_ref, 0);
+ idr_retry:
+	if (!idr_pre_get(&dma_idr, GFP_KERNEL))
+		return -ENOMEM;
+	mutex_lock(&dma_list_mutex);
+	rc = idr_get_new(&dma_idr, NULL, &device->dev_id);
+	mutex_unlock(&dma_list_mutex);
+	if (rc == -EAGAIN)
+		goto idr_retry;
+	else if (rc != 0)
+		return rc;
 
 	/* represent channels in sysfs. Probably want devs too */
 	list_for_each_entry(chan, &device->channels, device_node) {
 		chan->local = alloc_percpu(typeof(*chan->local));
 		if (chan->local == NULL)
 			continue;
+		chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL);
+		if (chan->dev == NULL) {
+			free_percpu(chan->local);
+			continue;
+		}
 
 		chan->chan_id = chancnt++;
-		chan->dev.class = &dma_devclass;
-		chan->dev.parent = device->dev;
-		snprintf(chan->dev.bus_id, BUS_ID_SIZE, "dma%dchan%d",
-		         device->dev_id, chan->chan_id);
-
-		rc = device_register(&chan->dev);
+		chan->dev->device.class = &dma_devclass;
+		chan->dev->device.parent = device->dev;
+		chan->dev->chan = chan;
+		chan->dev->idr_ref = idr_ref;
+		chan->dev->dev_id = device->dev_id;
+		atomic_inc(idr_ref);
+		dev_set_name(&chan->dev->device, "dma%dchan%d",
+			     device->dev_id, chan->chan_id);
+
+		rc = device_register(&chan->dev->device);
 		if (rc) {
-			chancnt--;
 			free_percpu(chan->local);
 			chan->local = NULL;
 			goto err_out;
 		}
-
-		/* One for the channel, one of the class device */
-		kref_get(&device->refcount);
-		kref_get(&device->refcount);
-		kref_init(&chan->refcount);
 		chan->client_count = 0;
-		chan->slow_ref = 0;
-		INIT_RCU_HEAD(&chan->rcu);
 	}
+	device->chancnt = chancnt;
 
 	mutex_lock(&dma_list_mutex);
-	list_add_tail(&device->global_node, &dma_device_list);
+	/* take references on public channels */
+	if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask))
+		list_for_each_entry(chan, &device->channels, device_node) {
+			/* if clients are already waiting for channels we need
+			 * to take references on their behalf
+			 */
+			if (dma_chan_get(chan) == -ENODEV) {
+				/* note we can only get here for the first
+				 * channel as the remaining channels are
+				 * guaranteed to get a reference
+				 */
+				rc = -ENODEV;
+				mutex_unlock(&dma_list_mutex);
+				goto err_out;
+			}
+		}
+	list_add_tail_rcu(&device->global_node, &dma_device_list);
+	dma_channel_rebalance();
 	mutex_unlock(&dma_list_mutex);
 
-	dma_clients_notify_available();
-
 	return 0;
 
 err_out:
 	list_for_each_entry(chan, &device->channels, device_node) {
 		if (chan->local == NULL)
 			continue;
-		kref_put(&device->refcount, dma_async_device_cleanup);
-		device_unregister(&chan->dev);
-		chancnt--;
+		mutex_lock(&dma_list_mutex);
+		chan->dev->chan = NULL;
+		mutex_unlock(&dma_list_mutex);
+		device_unregister(&chan->dev->device);
 		free_percpu(chan->local);
 	}
 	return rc;
@@ -441,37 +725,30 @@ err_out:
 EXPORT_SYMBOL(dma_async_device_register);
 
 /**
- * dma_async_device_cleanup - function called when all references are released
- * @kref: kernel reference object
- */
-static void dma_async_device_cleanup(struct kref *kref)
-{
-	struct dma_device *device;
-
-	device = container_of(kref, struct dma_device, refcount);
-	complete(&device->done);
-}
-
-/**
- * dma_async_device_unregister - unregisters DMA devices
+ * dma_async_device_unregister - unregister a DMA device
  * @device: &dma_device
+ *
+ * This routine is called by dma driver exit routines, dmaengine holds module
+ * references to prevent it being called while channels are in use.
  */
 void dma_async_device_unregister(struct dma_device *device)
 {
 	struct dma_chan *chan;
 
 	mutex_lock(&dma_list_mutex);
-	list_del(&device->global_node);
+	list_del_rcu(&device->global_node);
+	dma_channel_rebalance();
 	mutex_unlock(&dma_list_mutex);
 
 	list_for_each_entry(chan, &device->channels, device_node) {
-		dma_clients_notify_removed(chan);
-		device_unregister(&chan->dev);
-		dma_chan_release(chan);
+		WARN_ONCE(chan->client_count,
+			  "%s called while %d clients hold a reference\n",
+			  __func__, chan->client_count);
+		mutex_lock(&dma_list_mutex);
+		chan->dev->chan = NULL;
+		mutex_unlock(&dma_list_mutex);
+		device_unregister(&chan->dev->device);
 	}
-
-	kref_put(&device->refcount, dma_async_device_cleanup);
-	wait_for_completion(&device->done);
 }
 EXPORT_SYMBOL(dma_async_device_unregister);
 
@@ -623,10 +900,96 @@ void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
 }
 EXPORT_SYMBOL(dma_async_tx_descriptor_init);
 
+/* dma_wait_for_async_tx - spin wait for a transaction to complete
+ * @tx: in-flight transaction to wait on
+ *
+ * This routine assumes that tx was obtained from a call to async_memcpy,
+ * async_xor, async_memset, etc which ensures that tx is "in-flight" (prepped
+ * and submitted).  Walking the parent chain is only meant to cover for DMA
+ * drivers that do not implement the DMA_INTERRUPT capability and may race with
+ * the driver's descriptor cleanup routine.
+ */
+enum dma_status
+dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
+{
+	enum dma_status status;
+	struct dma_async_tx_descriptor *iter;
+	struct dma_async_tx_descriptor *parent;
+
+	if (!tx)
+		return DMA_SUCCESS;
+
+	WARN_ONCE(tx->parent, "%s: speculatively walking dependency chain for"
+		  " %s\n", __func__, dma_chan_name(tx->chan));
+
+	/* poll through the dependency chain, return when tx is complete */
+	do {
+		iter = tx;
+
+		/* find the root of the unsubmitted dependency chain */
+		do {
+			parent = iter->parent;
+			if (!parent)
+				break;
+			else
+				iter = parent;
+		} while (parent);
+
+		/* there is a small window for ->parent == NULL and
+		 * ->cookie == -EBUSY
+		 */
+		while (iter->cookie == -EBUSY)
+			cpu_relax();
+
+		status = dma_sync_wait(iter->chan, iter->cookie);
+	} while (status == DMA_IN_PROGRESS || (iter != tx));
+
+	return status;
+}
+EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
+
+/* dma_run_dependencies - helper routine for dma drivers to process
+ *	(start) dependent operations on their target channel
+ * @tx: transaction with dependencies
+ */
+void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
+{
+	struct dma_async_tx_descriptor *dep = tx->next;
+	struct dma_async_tx_descriptor *dep_next;
+	struct dma_chan *chan;
+
+	if (!dep)
+		return;
+
+	chan = dep->chan;
+
+	/* keep submitting up until a channel switch is detected
+	 * in that case we will be called again as a result of
+	 * processing the interrupt from async_tx_channel_switch
+	 */
+	for (; dep; dep = dep_next) {
+		spin_lock_bh(&dep->lock);
+		dep->parent = NULL;
+		dep_next = dep->next;
+		if (dep_next && dep_next->chan == chan)
+			dep->next = NULL; /* ->next will be submitted */
+		else
+			dep_next = NULL; /* submit current dep and terminate */
+		spin_unlock_bh(&dep->lock);
+
+		dep->tx_submit(dep);
+	}
+
+	chan->device->device_issue_pending(chan);
+}
+EXPORT_SYMBOL_GPL(dma_run_dependencies);
+
 static int __init dma_bus_init(void)
 {
+	idr_init(&dma_idr);
 	mutex_init(&dma_list_mutex);
 	return class_register(&dma_devclass);
 }
-subsys_initcall(dma_bus_init);
+arch_initcall(dma_bus_init);
+
 
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index d1e381e35a9..3603f1ea5b2 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -20,11 +20,11 @@ static unsigned int test_buf_size = 16384;
 module_param(test_buf_size, uint, S_IRUGO);
 MODULE_PARM_DESC(test_buf_size, "Size of the memcpy test buffer");
 
-static char test_channel[BUS_ID_SIZE];
+static char test_channel[20];
 module_param_string(channel, test_channel, sizeof(test_channel), S_IRUGO);
 MODULE_PARM_DESC(channel, "Bus ID of the channel to test (default: any)");
 
-static char test_device[BUS_ID_SIZE];
+static char test_device[20];
 module_param_string(device, test_device, sizeof(test_device), S_IRUGO);
 MODULE_PARM_DESC(device, "Bus ID of the DMA Engine to test (default: any)");
 
@@ -35,7 +35,7 @@ MODULE_PARM_DESC(threads_per_chan,
 
 static unsigned int max_channels;
 module_param(max_channels, uint, S_IRUGO);
-MODULE_PARM_DESC(nr_channels,
+MODULE_PARM_DESC(max_channels,
 		"Maximum number of channels to use (default: all)");
 
 /*
@@ -71,7 +71,7 @@ struct dmatest_chan {
 
 /*
  * These are protected by dma_list_mutex since they're only used by
- * the DMA client event callback
+ * the DMA filter function callback
  */
 static LIST_HEAD(dmatest_channels);
 static unsigned int nr_channels;
@@ -80,14 +80,14 @@ static bool dmatest_match_channel(struct dma_chan *chan)
 {
 	if (test_channel[0] == '\0')
 		return true;
-	return strcmp(chan->dev.bus_id, test_channel) == 0;
+	return strcmp(dma_chan_name(chan), test_channel) == 0;
 }
 
 static bool dmatest_match_device(struct dma_device *device)
 {
 	if (test_device[0] == '\0')
 		return true;
-	return strcmp(device->dev->bus_id, test_device) == 0;
+	return strcmp(dev_name(device->dev), test_device) == 0;
 }
 
 static unsigned long dmatest_random(void)
@@ -215,7 +215,6 @@ static int dmatest_func(void *data)
 
 	smp_rmb();
 	chan = thread->chan;
-	dma_chan_get(chan);
 
 	while (!kthread_should_stop()) {
 		total_tests++;
@@ -293,7 +292,6 @@ static int dmatest_func(void *data)
 	}
 
 	ret = 0;
-	dma_chan_put(chan);
 	kfree(thread->dstbuf);
 err_dstbuf:
 	kfree(thread->srcbuf);
@@ -319,21 +317,16 @@ static void dmatest_cleanup_channel(struct dmatest_chan *dtc)
 	kfree(dtc);
 }
 
-static enum dma_state_client dmatest_add_channel(struct dma_chan *chan)
+static int dmatest_add_channel(struct dma_chan *chan)
 {
 	struct dmatest_chan	*dtc;
 	struct dmatest_thread	*thread;
 	unsigned int		i;
 
-	/* Have we already been told about this channel? */
-	list_for_each_entry(dtc, &dmatest_channels, node)
-		if (dtc->chan == chan)
-			return DMA_DUP;
-
 	dtc = kmalloc(sizeof(struct dmatest_chan), GFP_KERNEL);
 	if (!dtc) {
-		pr_warning("dmatest: No memory for %s\n", chan->dev.bus_id);
-		return DMA_NAK;
+		pr_warning("dmatest: No memory for %s\n", dma_chan_name(chan));
+		return -ENOMEM;
 	}
 
 	dtc->chan = chan;
@@ -343,16 +336,16 @@ static enum dma_state_client dmatest_add_channel(struct dma_chan *chan)
 		thread = kzalloc(sizeof(struct dmatest_thread), GFP_KERNEL);
 		if (!thread) {
 			pr_warning("dmatest: No memory for %s-test%u\n",
-					chan->dev.bus_id, i);
+				   dma_chan_name(chan), i);
 			break;
 		}
 		thread->chan = dtc->chan;
 		smp_wmb();
 		thread->task = kthread_run(dmatest_func, thread, "%s-test%u",
-				chan->dev.bus_id, i);
+				dma_chan_name(chan), i);
 		if (IS_ERR(thread->task)) {
 			pr_warning("dmatest: Failed to run thread %s-test%u\n",
-					chan->dev.bus_id, i);
+					dma_chan_name(chan), i);
 			kfree(thread);
 			break;
 		}
@@ -362,86 +355,62 @@ static enum dma_state_client dmatest_add_channel(struct dma_chan *chan)
 		list_add_tail(&thread->node, &dtc->threads);
 	}
 
-	pr_info("dmatest: Started %u threads using %s\n", i, chan->dev.bus_id);
+	pr_info("dmatest: Started %u threads using %s\n", i, dma_chan_name(chan));
 
 	list_add_tail(&dtc->node, &dmatest_channels);
 	nr_channels++;
 
-	return DMA_ACK;
-}
-
-static enum dma_state_client dmatest_remove_channel(struct dma_chan *chan)
-{
-	struct dmatest_chan	*dtc, *_dtc;
-
-	list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) {
-		if (dtc->chan == chan) {
-			list_del(&dtc->node);
-			dmatest_cleanup_channel(dtc);
-			pr_debug("dmatest: lost channel %s\n",
-					chan->dev.bus_id);
-			return DMA_ACK;
-		}
-	}
-
-	return DMA_DUP;
+	return 0;
 }
 
-/*
- * Start testing threads as new channels are assigned to us, and kill
- * them when the channels go away.
- *
- * When we unregister the client, all channels are removed so this
- * will also take care of cleaning things up when the module is
- * unloaded.
- */
-static enum dma_state_client
-dmatest_event(struct dma_client *client, struct dma_chan *chan,
-		enum dma_state state)
+static bool filter(struct dma_chan *chan, void *param)
 {
-	enum dma_state_client	ack = DMA_NAK;
-
-	switch (state) {
-	case DMA_RESOURCE_AVAILABLE:
-		if (!dmatest_match_channel(chan)
-				|| !dmatest_match_device(chan->device))
-			ack = DMA_DUP;
-		else if (max_channels && nr_channels >= max_channels)
-			ack = DMA_NAK;
-		else
-			ack = dmatest_add_channel(chan);
-		break;
-
-	case DMA_RESOURCE_REMOVED:
-		ack = dmatest_remove_channel(chan);
-		break;
-
-	default:
-		pr_info("dmatest: Unhandled event %u (%s)\n",
-				state, chan->dev.bus_id);
-		break;
-	}
-
-	return ack;
+	if (!dmatest_match_channel(chan) || !dmatest_match_device(chan->device))
+		return false;
+	else
+		return true;
 }
 
-static struct dma_client dmatest_client = {
-	.event_callback	= dmatest_event,
-};
-
 static int __init dmatest_init(void)
 {
-	dma_cap_set(DMA_MEMCPY, dmatest_client.cap_mask);
-	dma_async_client_register(&dmatest_client);
-	dma_async_client_chan_request(&dmatest_client);
+	dma_cap_mask_t mask;
+	struct dma_chan *chan;
+	int err = 0;
+
+	dma_cap_zero(mask);
+	dma_cap_set(DMA_MEMCPY, mask);
+	for (;;) {
+		chan = dma_request_channel(mask, filter, NULL);
+		if (chan) {
+			err = dmatest_add_channel(chan);
+			if (err == 0)
+				continue;
+			else {
+				dma_release_channel(chan);
+				break; /* add_channel failed, punt */
+			}
+		} else
+			break; /* no more channels available */
+		if (max_channels && nr_channels >= max_channels)
+			break; /* we have all we need */
+	}
 
-	return 0;
+	return err;
 }
-module_init(dmatest_init);
+/* when compiled-in wait for drivers to load first */
+late_initcall(dmatest_init);
 
 static void __exit dmatest_exit(void)
 {
-	dma_async_client_unregister(&dmatest_client);
+	struct dmatest_chan *dtc, *_dtc;
+
+	list_for_each_entry_safe(dtc, _dtc, &dmatest_channels, node) {
+		list_del(&dtc->node);
+		dmatest_cleanup_channel(dtc);
+		pr_debug("dmatest: dropped channel %s\n",
+			 dma_chan_name(dtc->chan));
+		dma_release_channel(dtc->chan);
+	}
 }
 module_exit(dmatest_exit);
 
diff --git a/drivers/dma/dw_dmac.c b/drivers/dma/dw_dmac.c
index 0778d99aea7..6b702cc46b3 100644
--- a/drivers/dma/dw_dmac.c
+++ b/drivers/dma/dw_dmac.c
@@ -70,6 +70,15 @@
  * the controller, though.
  */
 
+static struct device *chan2dev(struct dma_chan *chan)
+{
+	return &chan->dev->device;
+}
+static struct device *chan2parent(struct dma_chan *chan)
+{
+	return chan->dev->device.parent;
+}
+
 static struct dw_desc *dwc_first_active(struct dw_dma_chan *dwc)
 {
 	return list_entry(dwc->active_list.next, struct dw_desc, desc_node);
@@ -93,12 +102,12 @@ static struct dw_desc *dwc_desc_get(struct dw_dma_chan *dwc)
 			ret = desc;
 			break;
 		}
-		dev_dbg(&dwc->chan.dev, "desc %p not ACKed\n", desc);
+		dev_dbg(chan2dev(&dwc->chan), "desc %p not ACKed\n", desc);
 		i++;
 	}
 	spin_unlock_bh(&dwc->lock);
 
-	dev_vdbg(&dwc->chan.dev, "scanned %u descriptors on freelist\n", i);
+	dev_vdbg(chan2dev(&dwc->chan), "scanned %u descriptors on freelist\n", i);
 
 	return ret;
 }
@@ -108,10 +117,10 @@ static void dwc_sync_desc_for_cpu(struct dw_dma_chan *dwc, struct dw_desc *desc)
 	struct dw_desc	*child;
 
 	list_for_each_entry(child, &desc->txd.tx_list, desc_node)
-		dma_sync_single_for_cpu(dwc->chan.dev.parent,
+		dma_sync_single_for_cpu(chan2parent(&dwc->chan),
 				child->txd.phys, sizeof(child->lli),
 				DMA_TO_DEVICE);
-	dma_sync_single_for_cpu(dwc->chan.dev.parent,
+	dma_sync_single_for_cpu(chan2parent(&dwc->chan),
 			desc->txd.phys, sizeof(desc->lli),
 			DMA_TO_DEVICE);
 }
@@ -129,11 +138,11 @@ static void dwc_desc_put(struct dw_dma_chan *dwc, struct dw_desc *desc)
 
 		spin_lock_bh(&dwc->lock);
 		list_for_each_entry(child, &desc->txd.tx_list, desc_node)
-			dev_vdbg(&dwc->chan.dev,
+			dev_vdbg(chan2dev(&dwc->chan),
 					"moving child desc %p to freelist\n",
 					child);
 		list_splice_init(&desc->txd.tx_list, &dwc->free_list);
-		dev_vdbg(&dwc->chan.dev, "moving desc %p to freelist\n", desc);
+		dev_vdbg(chan2dev(&dwc->chan), "moving desc %p to freelist\n", desc);
 		list_add(&desc->desc_node, &dwc->free_list);
 		spin_unlock_bh(&dwc->lock);
 	}
@@ -163,9 +172,9 @@ static void dwc_dostart(struct dw_dma_chan *dwc, struct dw_desc *first)
 
 	/* ASSERT:  channel is idle */
 	if (dma_readl(dw, CH_EN) & dwc->mask) {
-		dev_err(&dwc->chan.dev,
+		dev_err(chan2dev(&dwc->chan),
 			"BUG: Attempted to start non-idle channel\n");
-		dev_err(&dwc->chan.dev,
+		dev_err(chan2dev(&dwc->chan),
 			"  SAR: 0x%x DAR: 0x%x LLP: 0x%x CTL: 0x%x:%08x\n",
 			channel_readl(dwc, SAR),
 			channel_readl(dwc, DAR),
@@ -193,7 +202,7 @@ dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc)
 	void				*param;
 	struct dma_async_tx_descriptor	*txd = &desc->txd;
 
-	dev_vdbg(&dwc->chan.dev, "descriptor %u complete\n", txd->cookie);
+	dev_vdbg(chan2dev(&dwc->chan), "descriptor %u complete\n", txd->cookie);
 
 	dwc->completed = txd->cookie;
 	callback = txd->callback;
@@ -208,11 +217,11 @@ dwc_descriptor_complete(struct dw_dma_chan *dwc, struct dw_desc *desc)
 	 * mapped before they were submitted...
 	 */
 	if (!(txd->flags & DMA_COMPL_SKIP_DEST_UNMAP))
-		dma_unmap_page(dwc->chan.dev.parent, desc->lli.dar, desc->len,
-				DMA_FROM_DEVICE);
+		dma_unmap_page(chan2parent(&dwc->chan), desc->lli.dar,
+			       desc->len, DMA_FROM_DEVICE);
 	if (!(txd->flags & DMA_COMPL_SKIP_SRC_UNMAP))
-		dma_unmap_page(dwc->chan.dev.parent, desc->lli.sar, desc->len,
-				DMA_TO_DEVICE);
+		dma_unmap_page(chan2parent(&dwc->chan), desc->lli.sar,
+			       desc->len, DMA_TO_DEVICE);
 
 	/*
 	 * The API requires that no submissions are done from a
@@ -228,7 +237,7 @@ static void dwc_complete_all(struct dw_dma *dw, struct dw_dma_chan *dwc)
 	LIST_HEAD(list);
 
 	if (dma_readl(dw, CH_EN) & dwc->mask) {
-		dev_err(&dwc->chan.dev,
+		dev_err(chan2dev(&dwc->chan),
 			"BUG: XFER bit set, but channel not idle!\n");
 
 		/* Try to continue after resetting the channel... */
@@ -273,7 +282,7 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
 		return;
 	}
 
-	dev_vdbg(&dwc->chan.dev, "scan_descriptors: llp=0x%x\n", llp);
+	dev_vdbg(chan2dev(&dwc->chan), "scan_descriptors: llp=0x%x\n", llp);
 
 	list_for_each_entry_safe(desc, _desc, &dwc->active_list, desc_node) {
 		if (desc->lli.llp == llp)
@@ -292,7 +301,7 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
 		dwc_descriptor_complete(dwc, desc);
 	}
 
-	dev_err(&dwc->chan.dev,
+	dev_err(chan2dev(&dwc->chan),
 		"BUG: All descriptors done, but channel not idle!\n");
 
 	/* Try to continue after resetting the channel... */
@@ -308,7 +317,7 @@ static void dwc_scan_descriptors(struct dw_dma *dw, struct dw_dma_chan *dwc)
 
 static void dwc_dump_lli(struct dw_dma_chan *dwc, struct dw_lli *lli)
 {
-	dev_printk(KERN_CRIT, &dwc->chan.dev,
+	dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
 			"  desc: s0x%x d0x%x l0x%x c0x%x:%x\n",
 			lli->sar, lli->dar, lli->llp,
 			lli->ctlhi, lli->ctllo);
@@ -342,9 +351,9 @@ static void dwc_handle_error(struct dw_dma *dw, struct dw_dma_chan *dwc)
 	 * controller flagged an error instead of scribbling over
 	 * random memory locations.
 	 */
-	dev_printk(KERN_CRIT, &dwc->chan.dev,
+	dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
 			"Bad descriptor submitted for DMA!\n");
-	dev_printk(KERN_CRIT, &dwc->chan.dev,
+	dev_printk(KERN_CRIT, chan2dev(&dwc->chan),
 			"  cookie: %d\n", bad_desc->txd.cookie);
 	dwc_dump_lli(dwc, &bad_desc->lli);
 	list_for_each_entry(child, &bad_desc->txd.tx_list, desc_node)
@@ -442,12 +451,12 @@ static dma_cookie_t dwc_tx_submit(struct dma_async_tx_descriptor *tx)
 	 * for DMA. But this is hard to do in a race-free manner.
 	 */
 	if (list_empty(&dwc->active_list)) {
-		dev_vdbg(&tx->chan->dev, "tx_submit: started %u\n",
+		dev_vdbg(chan2dev(tx->chan), "tx_submit: started %u\n",
 				desc->txd.cookie);
 		dwc_dostart(dwc, desc);
 		list_add_tail(&desc->desc_node, &dwc->active_list);
 	} else {
-		dev_vdbg(&tx->chan->dev, "tx_submit: queued %u\n",
+		dev_vdbg(chan2dev(tx->chan), "tx_submit: queued %u\n",
 				desc->txd.cookie);
 
 		list_add_tail(&desc->desc_node, &dwc->queue);
@@ -472,11 +481,11 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 	unsigned int		dst_width;
 	u32			ctllo;
 
-	dev_vdbg(&chan->dev, "prep_dma_memcpy d0x%x s0x%x l0x%zx f0x%lx\n",
+	dev_vdbg(chan2dev(chan), "prep_dma_memcpy d0x%x s0x%x l0x%zx f0x%lx\n",
 			dest, src, len, flags);
 
 	if (unlikely(!len)) {
-		dev_dbg(&chan->dev, "prep_dma_memcpy: length is zero!\n");
+		dev_dbg(chan2dev(chan), "prep_dma_memcpy: length is zero!\n");
 		return NULL;
 	}
 
@@ -516,7 +525,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 			first = desc;
 		} else {
 			prev->lli.llp = desc->txd.phys;
-			dma_sync_single_for_device(chan->dev.parent,
+			dma_sync_single_for_device(chan2parent(chan),
 					prev->txd.phys, sizeof(prev->lli),
 					DMA_TO_DEVICE);
 			list_add_tail(&desc->desc_node,
@@ -531,7 +540,7 @@ dwc_prep_dma_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 		prev->lli.ctllo |= DWC_CTLL_INT_EN;
 
 	prev->lli.llp = 0;
-	dma_sync_single_for_device(chan->dev.parent,
+	dma_sync_single_for_device(chan2parent(chan),
 			prev->txd.phys, sizeof(prev->lli),
 			DMA_TO_DEVICE);
 
@@ -562,15 +571,15 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 	struct scatterlist	*sg;
 	size_t			total_len = 0;
 
-	dev_vdbg(&chan->dev, "prep_dma_slave\n");
+	dev_vdbg(chan2dev(chan), "prep_dma_slave\n");
 
 	if (unlikely(!dws || !sg_len))
 		return NULL;
 
-	reg_width = dws->slave.reg_width;
+	reg_width = dws->reg_width;
 	prev = first = NULL;
 
-	sg_len = dma_map_sg(chan->dev.parent, sgl, sg_len, direction);
+	sg_len = dma_map_sg(chan2parent(chan), sgl, sg_len, direction);
 
 	switch (direction) {
 	case DMA_TO_DEVICE:
@@ -579,7 +588,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 				| DWC_CTLL_DST_FIX
 				| DWC_CTLL_SRC_INC
 				| DWC_CTLL_FC_M2P);
-		reg = dws->slave.tx_reg;
+		reg = dws->tx_reg;
 		for_each_sg(sgl, sg, sg_len, i) {
 			struct dw_desc	*desc;
 			u32		len;
@@ -587,7 +596,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
 			desc = dwc_desc_get(dwc);
 			if (!desc) {
-				dev_err(&chan->dev,
+				dev_err(chan2dev(chan),
 					"not enough descriptors available\n");
 				goto err_desc_get;
 			}
@@ -607,7 +616,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 				first = desc;
 			} else {
 				prev->lli.llp = desc->txd.phys;
-				dma_sync_single_for_device(chan->dev.parent,
+				dma_sync_single_for_device(chan2parent(chan),
 						prev->txd.phys,
 						sizeof(prev->lli),
 						DMA_TO_DEVICE);
@@ -625,7 +634,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 				| DWC_CTLL_SRC_FIX
 				| DWC_CTLL_FC_P2M);
 
-		reg = dws->slave.rx_reg;
+		reg = dws->rx_reg;
 		for_each_sg(sgl, sg, sg_len, i) {
 			struct dw_desc	*desc;
 			u32		len;
@@ -633,7 +642,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 
 			desc = dwc_desc_get(dwc);
 			if (!desc) {
-				dev_err(&chan->dev,
+				dev_err(chan2dev(chan),
 					"not enough descriptors available\n");
 				goto err_desc_get;
 			}
@@ -653,7 +662,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 				first = desc;
 			} else {
 				prev->lli.llp = desc->txd.phys;
-				dma_sync_single_for_device(chan->dev.parent,
+				dma_sync_single_for_device(chan2parent(chan),
 						prev->txd.phys,
 						sizeof(prev->lli),
 						DMA_TO_DEVICE);
@@ -673,7 +682,7 @@ dwc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 		prev->lli.ctllo |= DWC_CTLL_INT_EN;
 
 	prev->lli.llp = 0;
-	dma_sync_single_for_device(chan->dev.parent,
+	dma_sync_single_for_device(chan2parent(chan),
 			prev->txd.phys, sizeof(prev->lli),
 			DMA_TO_DEVICE);
 
@@ -758,29 +767,21 @@ static void dwc_issue_pending(struct dma_chan *chan)
 	spin_unlock_bh(&dwc->lock);
 }
 
-static int dwc_alloc_chan_resources(struct dma_chan *chan,
-		struct dma_client *client)
+static int dwc_alloc_chan_resources(struct dma_chan *chan)
 {
 	struct dw_dma_chan	*dwc = to_dw_dma_chan(chan);
 	struct dw_dma		*dw = to_dw_dma(chan->device);
 	struct dw_desc		*desc;
-	struct dma_slave	*slave;
 	struct dw_dma_slave	*dws;
 	int			i;
 	u32			cfghi;
 	u32			cfglo;
 
-	dev_vdbg(&chan->dev, "alloc_chan_resources\n");
-
-	/* Channels doing slave DMA can only handle one client. */
-	if (dwc->dws || client->slave) {
-		if (chan->client_count)
-			return -EBUSY;
-	}
+	dev_vdbg(chan2dev(chan), "alloc_chan_resources\n");
 
 	/* ASSERT:  channel is idle */
 	if (dma_readl(dw, CH_EN) & dwc->mask) {
-		dev_dbg(&chan->dev, "DMA channel not idle?\n");
+		dev_dbg(chan2dev(chan), "DMA channel not idle?\n");
 		return -EIO;
 	}
 
@@ -789,23 +790,17 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,
 	cfghi = DWC_CFGH_FIFO_MODE;
 	cfglo = 0;
 
-	slave = client->slave;
-	if (slave) {
+	dws = dwc->dws;
+	if (dws) {
 		/*
 		 * We need controller-specific data to set up slave
 		 * transfers.
 		 */
-		BUG_ON(!slave->dma_dev || slave->dma_dev != dw->dma.dev);
-
-		dws = container_of(slave, struct dw_dma_slave, slave);
+		BUG_ON(!dws->dma_dev || dws->dma_dev != dw->dma.dev);
 
-		dwc->dws = dws;
 		cfghi = dws->cfg_hi;
 		cfglo = dws->cfg_lo;
-	} else {
-		dwc->dws = NULL;
 	}
-
 	channel_writel(dwc, CFG_LO, cfglo);
 	channel_writel(dwc, CFG_HI, cfghi);
 
@@ -822,7 +817,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,
 
 		desc = kzalloc(sizeof(struct dw_desc), GFP_KERNEL);
 		if (!desc) {
-			dev_info(&chan->dev,
+			dev_info(chan2dev(chan),
 				"only allocated %d descriptors\n", i);
 			spin_lock_bh(&dwc->lock);
 			break;
@@ -832,7 +827,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,
 		desc->txd.tx_submit = dwc_tx_submit;
 		desc->txd.flags = DMA_CTRL_ACK;
 		INIT_LIST_HEAD(&desc->txd.tx_list);
-		desc->txd.phys = dma_map_single(chan->dev.parent, &desc->lli,
+		desc->txd.phys = dma_map_single(chan2parent(chan), &desc->lli,
 				sizeof(desc->lli), DMA_TO_DEVICE);
 		dwc_desc_put(dwc, desc);
 
@@ -847,7 +842,7 @@ static int dwc_alloc_chan_resources(struct dma_chan *chan,
 
 	spin_unlock_bh(&dwc->lock);
 
-	dev_dbg(&chan->dev,
+	dev_dbg(chan2dev(chan),
 		"alloc_chan_resources allocated %d descriptors\n", i);
 
 	return i;
@@ -860,7 +855,7 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
 	struct dw_desc		*desc, *_desc;
 	LIST_HEAD(list);
 
-	dev_dbg(&chan->dev, "free_chan_resources (descs allocated=%u)\n",
+	dev_dbg(chan2dev(chan), "free_chan_resources (descs allocated=%u)\n",
 			dwc->descs_allocated);
 
 	/* ASSERT:  channel is idle */
@@ -881,13 +876,13 @@ static void dwc_free_chan_resources(struct dma_chan *chan)
 	spin_unlock_bh(&dwc->lock);
 
 	list_for_each_entry_safe(desc, _desc, &list, desc_node) {
-		dev_vdbg(&chan->dev, "  freeing descriptor %p\n", desc);
-		dma_unmap_single(chan->dev.parent, desc->txd.phys,
+		dev_vdbg(chan2dev(chan), "  freeing descriptor %p\n", desc);
+		dma_unmap_single(chan2parent(chan), desc->txd.phys,
 				sizeof(desc->lli), DMA_TO_DEVICE);
 		kfree(desc);
 	}
 
-	dev_vdbg(&chan->dev, "free_chan_resources done\n");
+	dev_vdbg(chan2dev(chan), "free_chan_resources done\n");
 }
 
 /*----------------------------------------------------------------------*/
diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index 0b95dcce447..ca70a21afc6 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -366,8 +366,7 @@ static struct fsl_desc_sw *fsl_dma_alloc_descriptor(
  *
  * Return - The number of descriptors allocated.
  */
-static int fsl_dma_alloc_chan_resources(struct dma_chan *chan,
-					struct dma_client *client)
+static int fsl_dma_alloc_chan_resources(struct dma_chan *chan)
 {
 	struct fsl_dma_chan *fsl_chan = to_fsl_chan(chan);
 
@@ -823,7 +822,7 @@ static int __devinit fsl_dma_chan_probe(struct fsl_dma_device *fdev,
 	 */
 	WARN_ON(fdev->feature != new_fsl_chan->feature);
 
-	new_fsl_chan->dev = &new_fsl_chan->common.dev;
+	new_fsl_chan->dev = &new_fsl_chan->common.dev->device;
 	new_fsl_chan->reg_base = ioremap(new_fsl_chan->reg.start,
 			new_fsl_chan->reg.end - new_fsl_chan->reg.start + 1);
 
diff --git a/drivers/dma/ioat.c b/drivers/dma/ioat.c
index 9b16a3af9a0..4105d6575b6 100644
--- a/drivers/dma/ioat.c
+++ b/drivers/dma/ioat.c
@@ -75,60 +75,10 @@ static int ioat_dca_enabled = 1;
 module_param(ioat_dca_enabled, int, 0644);
 MODULE_PARM_DESC(ioat_dca_enabled, "control support of dca service (default: 1)");
 
-static int ioat_setup_functionality(struct pci_dev *pdev, void __iomem *iobase)
-{
-	struct ioat_device *device = pci_get_drvdata(pdev);
-	u8 version;
-	int err = 0;
-
-	version = readb(iobase + IOAT_VER_OFFSET);
-	switch (version) {
-	case IOAT_VER_1_2:
-		device->dma = ioat_dma_probe(pdev, iobase);
-		if (device->dma && ioat_dca_enabled)
-			device->dca = ioat_dca_init(pdev, iobase);
-		break;
-	case IOAT_VER_2_0:
-		device->dma = ioat_dma_probe(pdev, iobase);
-		if (device->dma && ioat_dca_enabled)
-			device->dca = ioat2_dca_init(pdev, iobase);
-		break;
-	case IOAT_VER_3_0:
-		device->dma = ioat_dma_probe(pdev, iobase);
-		if (device->dma && ioat_dca_enabled)
-			device->dca = ioat3_dca_init(pdev, iobase);
-		break;
-	default:
-		err = -ENODEV;
-		break;
-	}
-	if (!device->dma)
-		err = -ENODEV;
-	return err;
-}
-
-static void ioat_shutdown_functionality(struct pci_dev *pdev)
-{
-	struct ioat_device *device = pci_get_drvdata(pdev);
-
-	dev_err(&pdev->dev, "Removing dma and dca services\n");
-	if (device->dca) {
-		unregister_dca_provider(device->dca);
-		free_dca_provider(device->dca);
-		device->dca = NULL;
-	}
-
-	if (device->dma) {
-		ioat_dma_remove(device->dma);
-		device->dma = NULL;
-	}
-}
-
 static struct pci_driver ioat_pci_driver = {
 	.name		= "ioatdma",
 	.id_table	= ioat_pci_tbl,
 	.probe		= ioat_probe,
-	.shutdown	= ioat_shutdown_functionality,
 	.remove		= __devexit_p(ioat_remove),
 };
 
@@ -179,7 +129,29 @@ static int __devinit ioat_probe(struct pci_dev *pdev,
 
 	pci_set_master(pdev);
 
-	err = ioat_setup_functionality(pdev, iobase);
+	switch (readb(iobase + IOAT_VER_OFFSET)) {
+	case IOAT_VER_1_2:
+		device->dma = ioat_dma_probe(pdev, iobase);
+		if (device->dma && ioat_dca_enabled)
+			device->dca = ioat_dca_init(pdev, iobase);
+		break;
+	case IOAT_VER_2_0:
+		device->dma = ioat_dma_probe(pdev, iobase);
+		if (device->dma && ioat_dca_enabled)
+			device->dca = ioat2_dca_init(pdev, iobase);
+		break;
+	case IOAT_VER_3_0:
+		device->dma = ioat_dma_probe(pdev, iobase);
+		if (device->dma && ioat_dca_enabled)
+			device->dca = ioat3_dca_init(pdev, iobase);
+		break;
+	default:
+		err = -ENODEV;
+		break;
+	}
+	if (!device->dma)
+		err = -ENODEV;
+
 	if (err)
 		goto err_version;
 
@@ -198,17 +170,21 @@ err_enable_device:
 	return err;
 }
 
-/*
- * It is unsafe to remove this module: if removed while a requested
- * dma is outstanding, esp. from tcp, it is possible to hang while
- * waiting for something that will never finish.  However, if you're
- * feeling lucky, this usually works just fine.
- */
 static void __devexit ioat_remove(struct pci_dev *pdev)
 {
 	struct ioat_device *device = pci_get_drvdata(pdev);
 
-	ioat_shutdown_functionality(pdev);
+	dev_err(&pdev->dev, "Removing dma and dca services\n");
+	if (device->dca) {
+		unregister_dca_provider(device->dca);
+		free_dca_provider(device->dca);
+		device->dca = NULL;
+	}
+
+	if (device->dma) {
+		ioat_dma_remove(device->dma);
+		device->dma = NULL;
+	}
 
 	kfree(device);
 }
diff --git a/drivers/dma/ioat_dma.c b/drivers/dma/ioat_dma.c
index b0438c4f0c3..b3759c4b653 100644
--- a/drivers/dma/ioat_dma.c
+++ b/drivers/dma/ioat_dma.c
@@ -525,7 +525,7 @@ static dma_cookie_t ioat1_tx_submit(struct dma_async_tx_descriptor *tx)
 	}
 
 	hw->ctl = IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
-	if (new->async_tx.callback) {
+	if (first->async_tx.callback) {
 		hw->ctl |= IOAT_DMA_DESCRIPTOR_CTL_INT_GN;
 		if (first != new) {
 			/* move callback into to last desc */
@@ -617,7 +617,7 @@ static dma_cookie_t ioat2_tx_submit(struct dma_async_tx_descriptor *tx)
 	}
 
 	hw->ctl |= IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
-	if (new->async_tx.callback) {
+	if (first->async_tx.callback) {
 		hw->ctl |= IOAT_DMA_DESCRIPTOR_CTL_INT_GN;
 		if (first != new) {
 			/* move callback into to last desc */
@@ -734,8 +734,7 @@ static void ioat2_dma_massage_chan_desc(struct ioat_dma_chan *ioat_chan)
  * ioat_dma_alloc_chan_resources - returns the number of allocated descriptors
  * @chan: the channel to be filled out
  */
-static int ioat_dma_alloc_chan_resources(struct dma_chan *chan,
-					 struct dma_client *client)
+static int ioat_dma_alloc_chan_resources(struct dma_chan *chan)
 {
 	struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
 	struct ioat_desc_sw *desc;
@@ -807,6 +806,12 @@ static void ioat_dma_free_chan_resources(struct dma_chan *chan)
 	struct ioat_desc_sw *desc, *_desc;
 	int in_use_descs = 0;
 
+	/* Before freeing channel resources first check
+	 * if they have been previously allocated for this channel.
+	 */
+	if (ioat_chan->desccount == 0)
+		return;
+
 	tasklet_disable(&ioat_chan->cleanup_task);
 	ioat_dma_memcpy_cleanup(ioat_chan);
 
@@ -869,6 +874,7 @@ static void ioat_dma_free_chan_resources(struct dma_chan *chan)
 	ioat_chan->last_completion = ioat_chan->completion_addr = 0;
 	ioat_chan->pending = 0;
 	ioat_chan->dmacount = 0;
+	ioat_chan->desccount = 0;
 	ioat_chan->watchdog_completion = 0;
 	ioat_chan->last_compl_desc_addr_hw = 0;
 	ioat_chan->watchdog_tcp_cookie =
@@ -1336,8 +1342,9 @@ static void ioat_dma_start_null_desc(struct ioat_dma_chan *ioat_chan)
 
 static void ioat_dma_test_callback(void *dma_async_param)
 {
-	printk(KERN_ERR "ioatdma: ioat_dma_test_callback(%p)\n",
-		dma_async_param);
+	struct completion *cmp = dma_async_param;
+
+	complete(cmp);
 }
 
 /**
@@ -1354,6 +1361,7 @@ static int ioat_dma_self_test(struct ioatdma_device *device)
 	dma_addr_t dma_dest, dma_src;
 	dma_cookie_t cookie;
 	int err = 0;
+	struct completion cmp;
 
 	src = kzalloc(sizeof(u8) * IOAT_TEST_SIZE, GFP_KERNEL);
 	if (!src)
@@ -1372,7 +1380,7 @@ static int ioat_dma_self_test(struct ioatdma_device *device)
 	dma_chan = container_of(device->common.channels.next,
 				struct dma_chan,
 				device_node);
-	if (device->common.device_alloc_chan_resources(dma_chan, NULL) < 1) {
+	if (device->common.device_alloc_chan_resources(dma_chan) < 1) {
 		dev_err(&device->pdev->dev,
 			"selftest cannot allocate chan resource\n");
 		err = -ENODEV;
@@ -1393,8 +1401,9 @@ static int ioat_dma_self_test(struct ioatdma_device *device)
 	}
 
 	async_tx_ack(tx);
+	init_completion(&cmp);
 	tx->callback = ioat_dma_test_callback;
-	tx->callback_param = (void *)0x8086;
+	tx->callback_param = &cmp;
 	cookie = tx->tx_submit(tx);
 	if (cookie < 0) {
 		dev_err(&device->pdev->dev,
@@ -1403,7 +1412,8 @@ static int ioat_dma_self_test(struct ioatdma_device *device)
 		goto free_resources;
 	}
 	device->common.device_issue_pending(dma_chan);
-	msleep(1);
+
+	wait_for_completion_timeout(&cmp, msecs_to_jiffies(3000));
 
 	if (device->common.device_is_tx_complete(dma_chan, cookie, NULL, NULL)
 					!= DMA_SUCCESS) {
diff --git a/drivers/dma/iop-adma.c b/drivers/dma/iop-adma.c
index 71fba82462c..ea5440dd10d 100644
--- a/drivers/dma/iop-adma.c
+++ b/drivers/dma/iop-adma.c
@@ -24,7 +24,6 @@
 
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/async_tx.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/spinlock.h>
@@ -85,18 +84,28 @@ iop_adma_run_tx_complete_actions(struct iop_adma_desc_slot *desc,
 			enum dma_ctrl_flags flags = desc->async_tx.flags;
 			u32 src_cnt;
 			dma_addr_t addr;
+			dma_addr_t dest;
 
+			src_cnt = unmap->unmap_src_cnt;
+			dest = iop_desc_get_dest_addr(unmap, iop_chan);
 			if (!(flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
-				addr = iop_desc_get_dest_addr(unmap, iop_chan);
-				dma_unmap_page(dev, addr, len, DMA_FROM_DEVICE);
+				enum dma_data_direction dir;
+
+				if (src_cnt > 1) /* is xor? */
+					dir = DMA_BIDIRECTIONAL;
+				else
+					dir = DMA_FROM_DEVICE;
+
+				dma_unmap_page(dev, dest, len, dir);
 			}
 
 			if (!(flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
-				src_cnt = unmap->unmap_src_cnt;
 				while (src_cnt--) {
 					addr = iop_desc_get_src_addr(unmap,
 								     iop_chan,
 								     src_cnt);
+					if (addr == dest)
+						continue;
 					dma_unmap_page(dev, addr, len,
 						       DMA_TO_DEVICE);
 				}
@@ -106,7 +115,7 @@ iop_adma_run_tx_complete_actions(struct iop_adma_desc_slot *desc,
 	}
 
 	/* run dependent operations */
-	async_tx_run_dependencies(&desc->async_tx);
+	dma_run_dependencies(&desc->async_tx);
 
 	return cookie;
 }
@@ -260,8 +269,6 @@ static void __iop_adma_slot_cleanup(struct iop_adma_chan *iop_chan)
 			break;
 	}
 
-	BUG_ON(!seen_current);
-
 	if (cookie > 0) {
 		iop_chan->completed_cookie = cookie;
 		pr_debug("\tcompleted cookie %d\n", cookie);
@@ -411,6 +418,7 @@ iop_adma_tx_submit(struct dma_async_tx_descriptor *tx)
 	int slot_cnt;
 	int slots_per_op;
 	dma_cookie_t cookie;
+	dma_addr_t next_dma;
 
 	grp_start = sw_desc->group_head;
 	slot_cnt = grp_start->slot_cnt;
@@ -425,12 +433,12 @@ iop_adma_tx_submit(struct dma_async_tx_descriptor *tx)
 			 &old_chain_tail->chain_node);
 
 	/* fix up the hardware chain */
-	iop_desc_set_next_desc(old_chain_tail, grp_start->async_tx.phys);
+	next_dma = grp_start->async_tx.phys;
+	iop_desc_set_next_desc(old_chain_tail, next_dma);
+	BUG_ON(iop_desc_get_next_desc(old_chain_tail) != next_dma); /* flush */
 
-	/* 1/ don't add pre-chained descriptors
-	 * 2/ dummy read to flush next_desc write
-	 */
-	BUG_ON(iop_desc_get_next_desc(sw_desc));
+	/* check for pre-chained descriptors */
+	iop_paranoia(iop_desc_get_next_desc(sw_desc));
 
 	/* increment the pending count by the number of slots
 	 * memcpy operations have a 1:1 (slot:operation) relation
@@ -460,8 +468,7 @@ static void iop_chan_start_null_xor(struct iop_adma_chan *iop_chan);
  * greater than 2x the number slots needed to satisfy a device->max_xor
  * request.
  * */
-static int iop_adma_alloc_chan_resources(struct dma_chan *chan,
-					 struct dma_client *client)
+static int iop_adma_alloc_chan_resources(struct dma_chan *chan)
 {
 	char *hw_desc;
 	int idx;
@@ -855,7 +862,7 @@ static int __devinit iop_adma_memcpy_self_test(struct iop_adma_device *device)
 	dma_chan = container_of(device->common.channels.next,
 				struct dma_chan,
 				device_node);
-	if (iop_adma_alloc_chan_resources(dma_chan, NULL) < 1) {
+	if (iop_adma_alloc_chan_resources(dma_chan) < 1) {
 		err = -ENODEV;
 		goto out;
 	}
@@ -953,7 +960,7 @@ iop_adma_xor_zero_sum_self_test(struct iop_adma_device *device)
 	dma_chan = container_of(device->common.channels.next,
 				struct dma_chan,
 				device_node);
-	if (iop_adma_alloc_chan_resources(dma_chan, NULL) < 1) {
+	if (iop_adma_alloc_chan_resources(dma_chan) < 1) {
 		err = -ENODEV;
 		goto out;
 	}
@@ -1104,26 +1111,13 @@ static int __devexit iop_adma_remove(struct platform_device *dev)
 	struct iop_adma_device *device = platform_get_drvdata(dev);
 	struct dma_chan *chan, *_chan;
 	struct iop_adma_chan *iop_chan;
-	int i;
 	struct iop_adma_platform_data *plat_data = dev->dev.platform_data;
 
 	dma_async_device_unregister(&device->common);
 
-	for (i = 0; i < 3; i++) {
-		unsigned int irq;
-		irq = platform_get_irq(dev, i);
-		free_irq(irq, device);
-	}
-
 	dma_free_coherent(&dev->dev, plat_data->pool_size,
 			device->dma_desc_pool_virt, device->dma_desc_pool);
 
-	do {
-		struct resource *res;
-		res = platform_get_resource(dev, IORESOURCE_MEM, 0);
-		release_mem_region(res->start, res->end - res->start);
-	} while (0);
-
 	list_for_each_entry_safe(chan, _chan, &device->common.channels,
 				device_node) {
 		iop_chan = to_iop_adma_chan(chan);
@@ -1244,7 +1238,6 @@ static int __devinit iop_adma_probe(struct platform_device *pdev)
 	spin_lock_init(&iop_chan->lock);
 	INIT_LIST_HEAD(&iop_chan->chain);
 	INIT_LIST_HEAD(&iop_chan->all_slots);
-	INIT_RCU_HEAD(&iop_chan->common.rcu);
 	iop_chan->common.device = dma_dev;
 	list_add_tail(&iop_chan->common.device_node, &dma_dev->channels);
 
@@ -1420,16 +1413,12 @@ static int __init iop_adma_init (void)
 	return platform_driver_register(&iop_adma_driver);
 }
 
-/* it's currently unsafe to unload this module */
-#if 0
 static void __exit iop_adma_exit (void)
 {
 	platform_driver_unregister(&iop_adma_driver);
 	return;
 }
 module_exit(iop_adma_exit);
-#endif
-
 module_init(iop_adma_init);
 
 MODULE_AUTHOR("Intel Corporation");
diff --git a/drivers/dma/iovlock.c b/drivers/dma/iovlock.c
index e763d723e4c..9f6fe46a9b8 100644
--- a/drivers/dma/iovlock.c
+++ b/drivers/dma/iovlock.c
@@ -55,7 +55,6 @@ struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len)
 	int nr_iovecs = 0;
 	int iovec_len_used = 0;
 	int iovec_pages_used = 0;
-	long err;
 
 	/* don't pin down non-user-based iovecs */
 	if (segment_eq(get_fs(), KERNEL_DS))
@@ -72,23 +71,21 @@ struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len)
 	local_list = kmalloc(sizeof(*local_list)
 		+ (nr_iovecs * sizeof (struct dma_page_list))
 		+ (iovec_pages_used * sizeof (struct page*)), GFP_KERNEL);
-	if (!local_list) {
-		err = -ENOMEM;
+	if (!local_list)
 		goto out;
-	}
 
 	/* list of pages starts right after the page list array */
 	pages = (struct page **) &local_list->page_list[nr_iovecs];
 
+	local_list->nr_iovecs = 0;
+
 	for (i = 0; i < nr_iovecs; i++) {
 		struct dma_page_list *page_list = &local_list->page_list[i];
 
 		len -= iov[i].iov_len;
 
-		if (!access_ok(VERIFY_WRITE, iov[i].iov_base, iov[i].iov_len)) {
-			err = -EFAULT;
+		if (!access_ok(VERIFY_WRITE, iov[i].iov_base, iov[i].iov_len))
 			goto unpin;
-		}
 
 		page_list->nr_pages = num_pages_spanned(&iov[i]);
 		page_list->base_address = iov[i].iov_base;
@@ -109,10 +106,8 @@ struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len)
 			NULL);
 		up_read(&current->mm->mmap_sem);
 
-		if (ret != page_list->nr_pages) {
-			err = -ENOMEM;
+		if (ret != page_list->nr_pages)
 			goto unpin;
-		}
 
 		local_list->nr_iovecs = i + 1;
 	}
@@ -122,7 +117,7 @@ struct dma_pinned_list *dma_pin_iovec_pages(struct iovec *iov, size_t len)
 unpin:
 	dma_unpin_iovec_pages(local_list);
 out:
-	return ERR_PTR(err);
+	return NULL;
 }
 
 void dma_unpin_iovec_pages(struct dma_pinned_list *pinned_list)
diff --git a/drivers/dma/mv_xor.c b/drivers/dma/mv_xor.c
index 0328da020a1..d35cbd1ff0b 100644
--- a/drivers/dma/mv_xor.c
+++ b/drivers/dma/mv_xor.c
@@ -18,7 +18,6 @@
 
 #include <linux/init.h>
 #include <linux/module.h>
-#include <linux/async_tx.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/spinlock.h>
@@ -311,17 +310,26 @@ mv_xor_run_tx_complete_actions(struct mv_xor_desc_slot *desc,
 			enum dma_ctrl_flags flags = desc->async_tx.flags;
 			u32 src_cnt;
 			dma_addr_t addr;
+			dma_addr_t dest;
 
+			src_cnt = unmap->unmap_src_cnt;
+			dest = mv_desc_get_dest_addr(unmap);
 			if (!(flags & DMA_COMPL_SKIP_DEST_UNMAP)) {
-				addr = mv_desc_get_dest_addr(unmap);
-				dma_unmap_page(dev, addr, len, DMA_FROM_DEVICE);
+				enum dma_data_direction dir;
+
+				if (src_cnt > 1) /* is xor ? */
+					dir = DMA_BIDIRECTIONAL;
+				else
+					dir = DMA_FROM_DEVICE;
+				dma_unmap_page(dev, dest, len, dir);
 			}
 
 			if (!(flags & DMA_COMPL_SKIP_SRC_UNMAP)) {
-				src_cnt = unmap->unmap_src_cnt;
 				while (src_cnt--) {
 					addr = mv_desc_get_src_addr(unmap,
 								    src_cnt);
+					if (addr == dest)
+						continue;
 					dma_unmap_page(dev, addr, len,
 						       DMA_TO_DEVICE);
 				}
@@ -331,7 +339,7 @@ mv_xor_run_tx_complete_actions(struct mv_xor_desc_slot *desc,
 	}
 
 	/* run dependent operations */
-	async_tx_run_dependencies(&desc->async_tx);
+	dma_run_dependencies(&desc->async_tx);
 
 	return cookie;
 }
@@ -598,8 +606,7 @@ submit_done:
 }
 
 /* returns the number of allocated descriptors */
-static int mv_xor_alloc_chan_resources(struct dma_chan *chan,
-				       struct dma_client *client)
+static int mv_xor_alloc_chan_resources(struct dma_chan *chan)
 {
 	char *hw_desc;
 	int idx;
@@ -949,7 +956,7 @@ static int __devinit mv_xor_memcpy_self_test(struct mv_xor_device *device)
 	dma_chan = container_of(device->common.channels.next,
 				struct dma_chan,
 				device_node);
-	if (mv_xor_alloc_chan_resources(dma_chan, NULL) < 1) {
+	if (mv_xor_alloc_chan_resources(dma_chan) < 1) {
 		err = -ENODEV;
 		goto out;
 	}
@@ -1044,7 +1051,7 @@ mv_xor_xor_self_test(struct mv_xor_device *device)
 	dma_chan = container_of(device->common.channels.next,
 				struct dma_chan,
 				device_node);
-	if (mv_xor_alloc_chan_resources(dma_chan, NULL) < 1) {
+	if (mv_xor_alloc_chan_resources(dma_chan) < 1) {
 		err = -ENODEV;
 		goto out;
 	}
@@ -1212,7 +1219,6 @@ static int __devinit mv_xor_probe(struct platform_device *pdev)
 	INIT_LIST_HEAD(&mv_chan->chain);
 	INIT_LIST_HEAD(&mv_chan->completed_slots);
 	INIT_LIST_HEAD(&mv_chan->all_slots);
-	INIT_RCU_HEAD(&mv_chan->common.rcu);
 	mv_chan->common.device = dma_dev;
 
 	list_add_tail(&mv_chan->common.device_node, &dma_dev->channels);