1 files changed, 177 insertions, 387 deletions

diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c
index 2be3bae8993..39ea4791a3c 100644
--- a/crypto/async_tx/async_tx.c
+++ b/crypto/async_tx/async_tx.c
@@ -23,439 +23,220 @@
  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  *
  */
+#include <linux/rculist.h>
+#include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/async_tx.h>
 
 #ifdef CONFIG_DMA_ENGINE
-static enum dma_state_client
-dma_channel_add_remove(struct dma_client *client,
-	struct dma_chan *chan, enum dma_state state);
-
-static struct dma_client async_tx_dma = {
-	.event_callback = dma_channel_add_remove,
-	/* .cap_mask == 0 defaults to all channels */
-};
-
-/**
- * dma_cap_mask_all - enable iteration over all operation types
- */
-static dma_cap_mask_t dma_cap_mask_all;
-
-/**
- * chan_ref_percpu - tracks channel allocations per core/opertion
- */
-struct chan_ref_percpu {
-	struct dma_chan_ref *ref;
-};
-
-static int channel_table_initialized;
-static struct chan_ref_percpu *channel_table[DMA_TX_TYPE_END];
-
-/**
- * async_tx_lock - protect modification of async_tx_master_list and serialize
- *	rebalance operations
- */
-static spinlock_t async_tx_lock;
-
-static LIST_HEAD(async_tx_master_list);
-
-/* async_tx_issue_pending_all - start all transactions on all channels */
-void async_tx_issue_pending_all(void)
-{
-	struct dma_chan_ref *ref;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(ref, &async_tx_master_list, node)
-		ref->chan->device->device_issue_pending(ref->chan);
-	rcu_read_unlock();
-}
-EXPORT_SYMBOL_GPL(async_tx_issue_pending_all);
-
-/* dma_wait_for_async_tx - spin wait for a transcation to complete
- * @tx: transaction to wait on
- */
-enum dma_status
-dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
+static int __init async_tx_init(void)
 {
-	enum dma_status status;
-	struct dma_async_tx_descriptor *iter;
-	struct dma_async_tx_descriptor *parent;
-
-	if (!tx)
-		return DMA_SUCCESS;
-
-	/* poll through the dependency chain, return when tx is complete */
-	do {
-		iter = tx;
-
-		/* find the root of the unsubmitted dependency chain */
-		while (iter->cookie == -EBUSY) {
-			parent = iter->parent;
-			if (parent && parent->cookie == -EBUSY)
-				iter = iter->parent;
-			else
-				break;
-		}
-
-		status = dma_sync_wait(iter->chan, iter->cookie);
-	} while (status == DMA_IN_PROGRESS || (iter != tx));
+	async_dmaengine_get();
 
-	return status;
-}
-EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
-
-/* async_tx_run_dependencies - helper routine for dma drivers to process
- *	(start) dependent operations on their target channel
- * @tx: transaction with dependencies
- */
-void
-async_tx_run_dependencies(struct dma_async_tx_descriptor *tx)
-{
-	struct dma_async_tx_descriptor *dep_tx, *_dep_tx;
-	struct dma_device *dev;
-	struct dma_chan *chan;
+	printk(KERN_INFO "async_tx: api initialized (async)\n");
 
-	list_for_each_entry_safe(dep_tx, _dep_tx, &tx->depend_list,
-		depend_node) {
-		chan = dep_tx->chan;
-		dev = chan->device;
-		/* we can't depend on ourselves */
-		BUG_ON(chan == tx->chan);
-		list_del(&dep_tx->depend_node);
-		tx->tx_submit(dep_tx);
-
-		/* we need to poke the engine as client code does not
-		 * know about dependency submission events
-		 */
-		dev->device_issue_pending(chan);
-	}
+	return 0;
 }
-EXPORT_SYMBOL_GPL(async_tx_run_dependencies);
 
-static void
-free_dma_chan_ref(struct rcu_head *rcu)
+static void __exit async_tx_exit(void)
 {
-	struct dma_chan_ref *ref;
-	ref = container_of(rcu, struct dma_chan_ref, rcu);
-	kfree(ref);
+	async_dmaengine_put();
 }
 
-static void
-init_dma_chan_ref(struct dma_chan_ref *ref, struct dma_chan *chan)
-{
-	INIT_LIST_HEAD(&ref->node);
-	INIT_RCU_HEAD(&ref->rcu);
-	ref->chan = chan;
-	atomic_set(&ref->count, 0);
-}
+module_init(async_tx_init);
+module_exit(async_tx_exit);
 
 /**
- * get_chan_ref_by_cap - returns the nth channel of the given capability
- * 	defaults to returning the channel with the desired capability and the
- * 	lowest reference count if the index can not be satisfied
- * @cap: capability to match
- * @index: nth channel desired, passing -1 has the effect of forcing the
- *  default return value
+ * __async_tx_find_channel - find a channel to carry out the operation or let
+ *	the transaction execute synchronously
+ * @submit: transaction dependency and submission modifiers
+ * @tx_type: transaction type
  */
-static struct dma_chan_ref *
-get_chan_ref_by_cap(enum dma_transaction_type cap, int index)
+struct dma_chan *
+__async_tx_find_channel(struct async_submit_ctl *submit,
+			enum dma_transaction_type tx_type)
 {
-	struct dma_chan_ref *ret_ref = NULL, *min_ref = NULL, *ref;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(ref, &async_tx_master_list, node)
-		if (dma_has_cap(cap, ref->chan->device->cap_mask)) {
-			if (!min_ref)
-				min_ref = ref;
-			else if (atomic_read(&ref->count) <
-				atomic_read(&min_ref->count))
-				min_ref = ref;
-
-			if (index-- == 0) {
-				ret_ref = ref;
-				break;
-			}
-		}
-	rcu_read_unlock();
-
-	if (!ret_ref)
-		ret_ref = min_ref;
+	struct dma_async_tx_descriptor *depend_tx = submit->depend_tx;
 
-	if (ret_ref)
-		atomic_inc(&ret_ref->count);
-
-	return ret_ref;
+	/* see if we can keep the chain on one channel */
+	if (depend_tx &&
+	    dma_has_cap(tx_type, depend_tx->chan->device->cap_mask))
+		return depend_tx->chan;
+	return async_dma_find_channel(tx_type);
 }
+EXPORT_SYMBOL_GPL(__async_tx_find_channel);
+#endif
+
 
 /**
- * async_tx_rebalance - redistribute the available channels, optimize
- * for cpu isolation in the SMP case, and opertaion isolation in the
- * uniprocessor case
+ * async_tx_channel_switch - queue an interrupt descriptor with a dependency
+ * 	pre-attached.
+ * @depend_tx: the operation that must finish before the new operation runs
+ * @tx: the new operation
  */
-static void async_tx_rebalance(void)
+static void
+async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx,
+			struct dma_async_tx_descriptor *tx)
 {
-	int cpu, cap, cpu_idx = 0;
-	unsigned long flags;
+	struct dma_chan *chan = depend_tx->chan;
+	struct dma_device *device = chan->device;
+	struct dma_async_tx_descriptor *intr_tx = (void *) ~0;
+
+	/* first check to see if we can still append to depend_tx */
+	txd_lock(depend_tx);
+	if (txd_parent(depend_tx) && depend_tx->chan == tx->chan) {
+		txd_chain(depend_tx, tx);
+		intr_tx = NULL;
+	}
+	txd_unlock(depend_tx);
 
-	if (!channel_table_initialized)
+	/* attached dependency, flush the parent channel */
+	if (!intr_tx) {
+		device->device_issue_pending(chan);
 		return;
-
-	spin_lock_irqsave(&async_tx_lock, flags);
-
-	/* undo the last distribution */
-	for_each_dma_cap_mask(cap, dma_cap_mask_all)
-		for_each_possible_cpu(cpu) {
-			struct dma_chan_ref *ref =
-				per_cpu_ptr(channel_table[cap], cpu)->ref;
-			if (ref) {
-				atomic_set(&ref->count, 0);
-				per_cpu_ptr(channel_table[cap], cpu)->ref =
-									NULL;
-			}
-		}
-
-	for_each_dma_cap_mask(cap, dma_cap_mask_all)
-		for_each_online_cpu(cpu) {
-			struct dma_chan_ref *new;
-			if (NR_CPUS > 1)
-				new = get_chan_ref_by_cap(cap, cpu_idx++);
-			else
-				new = get_chan_ref_by_cap(cap, -1);
-
-			per_cpu_ptr(channel_table[cap], cpu)->ref = new;
-		}
-
-	spin_unlock_irqrestore(&async_tx_lock, flags);
-}
-
-static enum dma_state_client
-dma_channel_add_remove(struct dma_client *client,
-	struct dma_chan *chan, enum dma_state state)
-{
-	unsigned long found, flags;
-	struct dma_chan_ref *master_ref, *ref;
-	enum dma_state_client ack = DMA_DUP; /* default: take no action */
-
-	switch (state) {
-	case DMA_RESOURCE_AVAILABLE:
-		found = 0;
-		rcu_read_lock();
-		list_for_each_entry_rcu(ref, &async_tx_master_list, node)
-			if (ref->chan == chan) {
-				found = 1;
-				break;
-			}
-		rcu_read_unlock();
-
-		pr_debug("async_tx: dma resource available [%s]\n",
-			found ? "old" : "new");
-
-		if (!found)
-			ack = DMA_ACK;
-		else
-			break;
-
-		/* add the channel to the generic management list */
-		master_ref = kmalloc(sizeof(*master_ref), GFP_KERNEL);
-		if (master_ref) {
-			/* keep a reference until async_tx is unloaded */
-			dma_chan_get(chan);
-			init_dma_chan_ref(master_ref, chan);
-			spin_lock_irqsave(&async_tx_lock, flags);
-			list_add_tail_rcu(&master_ref->node,
-				&async_tx_master_list);
-			spin_unlock_irqrestore(&async_tx_lock,
-				flags);
-		} else {
-			printk(KERN_WARNING "async_tx: unable to create"
-				" new master entry in response to"
-				" a DMA_RESOURCE_ADDED event"
-				" (-ENOMEM)\n");
-			return 0;
-		}
-
-		async_tx_rebalance();
-		break;
-	case DMA_RESOURCE_REMOVED:
-		found = 0;
-		spin_lock_irqsave(&async_tx_lock, flags);
-		list_for_each_entry_rcu(ref, &async_tx_master_list, node)
-			if (ref->chan == chan) {
-				/* permit backing devices to go away */
-				dma_chan_put(ref->chan);
-				list_del_rcu(&ref->node);
-				call_rcu(&ref->rcu, free_dma_chan_ref);
-				found = 1;
-				break;
-			}
-		spin_unlock_irqrestore(&async_tx_lock, flags);
-
-		pr_debug("async_tx: dma resource removed [%s]\n",
-			found ? "ours" : "not ours");
-
-		if (found)
-			ack = DMA_ACK;
-		else
-			break;
-
-		async_tx_rebalance();
-		break;
-	case DMA_RESOURCE_SUSPEND:
-	case DMA_RESOURCE_RESUME:
-		printk(KERN_WARNING "async_tx: does not support dma channel"
-			" suspend/resume\n");
-		break;
-	default:
-		BUG();
 	}
 
-	return ack;
-}
-
-static int __init
-async_tx_init(void)
-{
-	enum dma_transaction_type cap;
-
-	spin_lock_init(&async_tx_lock);
-	bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END);
-
-	/* an interrupt will never be an explicit operation type.
-	 * clearing this bit prevents allocation to a slot in 'channel_table'
+	/* see if we can schedule an interrupt
+	 * otherwise poll for completion
 	 */
-	clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits);
+	if (dma_has_cap(DMA_INTERRUPT, device->cap_mask))
+		intr_tx = device->device_prep_dma_interrupt(chan, 0);
+	else
+		intr_tx = NULL;
+
+	if (intr_tx) {
+		intr_tx->callback = NULL;
+		intr_tx->callback_param = NULL;
+		/* safe to chain outside the lock since we know we are
+		 * not submitted yet
+		 */
+		txd_chain(intr_tx, tx);
+
+		/* check if we need to append */
+		txd_lock(depend_tx);
+		if (txd_parent(depend_tx)) {
+			txd_chain(depend_tx, intr_tx);
+			async_tx_ack(intr_tx);
+			intr_tx = NULL;
+		}
+		txd_unlock(depend_tx);
 
-	for_each_dma_cap_mask(cap, dma_cap_mask_all) {
-		channel_table[cap] = alloc_percpu(struct chan_ref_percpu);
-		if (!channel_table[cap])
-			goto err;
+		if (intr_tx) {
+			txd_clear_parent(intr_tx);
+			intr_tx->tx_submit(intr_tx);
+			async_tx_ack(intr_tx);
+		}
+		device->device_issue_pending(chan);
+	} else {
+		if (dma_wait_for_async_tx(depend_tx) != DMA_COMPLETE)
+			panic("%s: DMA error waiting for depend_tx\n",
+			      __func__);
+		tx->tx_submit(tx);
 	}
-
-	channel_table_initialized = 1;
-	dma_async_client_register(&async_tx_dma);
-	dma_async_client_chan_request(&async_tx_dma);
-
-	printk(KERN_INFO "async_tx: api initialized (async)\n");
-
-	return 0;
-err:
-	printk(KERN_ERR "async_tx: initialization failure\n");
-
-	while (--cap >= 0)
-		free_percpu(channel_table[cap]);
-
-	return 1;
 }
 
-static void __exit async_tx_exit(void)
-{
-	enum dma_transaction_type cap;
-
-	channel_table_initialized = 0;
-
-	for_each_dma_cap_mask(cap, dma_cap_mask_all)
-		if (channel_table[cap])
-			free_percpu(channel_table[cap]);
-
-	dma_async_client_unregister(&async_tx_dma);
-}
 
 /**
- * __async_tx_find_channel - find a channel to carry out the operation or let
- *	the transaction execute synchronously
- * @depend_tx: transaction dependency
- * @tx_type: transaction type
+ * submit_disposition - flags for routing an incoming operation
+ * @ASYNC_TX_SUBMITTED: we were able to append the new operation under the lock
+ * @ASYNC_TX_CHANNEL_SWITCH: when the lock is dropped schedule a channel switch
+ * @ASYNC_TX_DIRECT_SUBMIT: when the lock is dropped submit directly
+ *
+ * while holding depend_tx->lock we must avoid submitting new operations
+ * to prevent a circular locking dependency with drivers that already
+ * hold a channel lock when calling async_tx_run_dependencies.
  */
-struct dma_chan *
-__async_tx_find_channel(struct dma_async_tx_descriptor *depend_tx,
-	enum dma_transaction_type tx_type)
-{
-	/* see if we can keep the chain on one channel */
-	if (depend_tx &&
-		dma_has_cap(tx_type, depend_tx->chan->device->cap_mask))
-		return depend_tx->chan;
-	else if (likely(channel_table_initialized)) {
-		struct dma_chan_ref *ref;
-		int cpu = get_cpu();
-		ref = per_cpu_ptr(channel_table[tx_type], cpu)->ref;
-		put_cpu();
-		return ref ? ref->chan : NULL;
-	} else
-		return NULL;
-}
-EXPORT_SYMBOL_GPL(__async_tx_find_channel);
-#else
-static int __init async_tx_init(void)
-{
-	printk(KERN_INFO "async_tx: api initialized (sync-only)\n");
-	return 0;
-}
-
-static void __exit async_tx_exit(void)
-{
-	do { } while (0);
-}
-#endif
+enum submit_disposition {
+	ASYNC_TX_SUBMITTED,
+	ASYNC_TX_CHANNEL_SWITCH,
+	ASYNC_TX_DIRECT_SUBMIT,
+};
 
 void
 async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx,
-	enum async_tx_flags flags, struct dma_async_tx_descriptor *depend_tx,
-	dma_async_tx_callback cb_fn, void *cb_param)
+		struct async_submit_ctl *submit)
 {
-	tx->callback = cb_fn;
-	tx->callback_param = cb_param;
+	struct dma_async_tx_descriptor *depend_tx = submit->depend_tx;
 
-	/* set this new tx to run after depend_tx if:
-	 * 1/ a dependency exists (depend_tx is !NULL)
-	 * 2/ the tx can not be submitted to the current channel
-	 */
-	if (depend_tx && depend_tx->chan != chan) {
-		/* if ack is already set then we cannot be sure
+	tx->callback = submit->cb_fn;
+	tx->callback_param = submit->cb_param;
+
+	if (depend_tx) {
+		enum submit_disposition s;
+
+		/* sanity check the dependency chain:
+		 * 1/ if ack is already set then we cannot be sure
 		 * we are referring to the correct operation
+		 * 2/ dependencies are 1:1 i.e. two transactions can
+		 * not depend on the same parent
+		 */
+		BUG_ON(async_tx_test_ack(depend_tx) || txd_next(depend_tx) ||
+		       txd_parent(tx));
+
+		/* the lock prevents async_tx_run_dependencies from missing
+		 * the setting of ->next when ->parent != NULL
 		 */
-		BUG_ON(depend_tx->ack);
-
-		tx->parent = depend_tx;
-		spin_lock_bh(&depend_tx->lock);
-		list_add_tail(&tx->depend_node, &depend_tx->depend_list);
-		if (depend_tx->cookie == 0) {
-			struct dma_chan *dep_chan = depend_tx->chan;
-			struct dma_device *dep_dev = dep_chan->device;
-			dep_dev->device_dependency_added(dep_chan);
+		txd_lock(depend_tx);
+		if (txd_parent(depend_tx)) {
+			/* we have a parent so we can not submit directly
+			 * if we are staying on the same channel: append
+			 * else: channel switch
+			 */
+			if (depend_tx->chan == chan) {
+				txd_chain(depend_tx, tx);
+				s = ASYNC_TX_SUBMITTED;
+			} else
+				s = ASYNC_TX_CHANNEL_SWITCH;
+		} else {
+			/* we do not have a parent so we may be able to submit
+			 * directly if we are staying on the same channel
+			 */
+			if (depend_tx->chan == chan)
+				s = ASYNC_TX_DIRECT_SUBMIT;
+			else
+				s = ASYNC_TX_CHANNEL_SWITCH;
 		}
-		spin_unlock_bh(&depend_tx->lock);
+		txd_unlock(depend_tx);
 
-		/* schedule an interrupt to trigger the channel switch */
-		async_trigger_callback(ASYNC_TX_ACK, depend_tx, NULL, NULL);
+		switch (s) {
+		case ASYNC_TX_SUBMITTED:
+			break;
+		case ASYNC_TX_CHANNEL_SWITCH:
+			async_tx_channel_switch(depend_tx, tx);
+			break;
+		case ASYNC_TX_DIRECT_SUBMIT:
+			txd_clear_parent(tx);
+			tx->tx_submit(tx);
+			break;
+		}
 	} else {
-		tx->parent = NULL;
+		txd_clear_parent(tx);
 		tx->tx_submit(tx);
 	}
 
-	if (flags & ASYNC_TX_ACK)
+	if (submit->flags & ASYNC_TX_ACK)
 		async_tx_ack(tx);
 
-	if (depend_tx && (flags & ASYNC_TX_DEP_ACK))
+	if (depend_tx)
 		async_tx_ack(depend_tx);
 }
 EXPORT_SYMBOL_GPL(async_tx_submit);
 
 /**
- * async_trigger_callback - schedules the callback function to be run after
- * any dependent operations have been completed.
- * @flags: ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
- * @depend_tx: 'callback' requires the completion of this transaction
- * @cb_fn: function to call after depend_tx completes
- * @cb_param: parameter to pass to the callback routine
+ * async_trigger_callback - schedules the callback function to be run
+ * @submit: submission and completion parameters
+ *
+ * honored flags: ASYNC_TX_ACK
+ *
+ * The callback is run after any dependent operations have completed.
  */
 struct dma_async_tx_descriptor *
-async_trigger_callback(enum async_tx_flags flags,
-	struct dma_async_tx_descriptor *depend_tx,
-	dma_async_tx_callback cb_fn, void *cb_param)
+async_trigger_callback(struct async_submit_ctl *submit)
 {
 	struct dma_chan *chan;
 	struct dma_device *device;
 	struct dma_async_tx_descriptor *tx;
+	struct dma_async_tx_descriptor *depend_tx = submit->depend_tx;
 
 	if (depend_tx) {
 		chan = depend_tx->chan;
@@ -467,37 +248,46 @@ async_trigger_callback(enum async_tx_flags flags,
 		if (device && !dma_has_cap(DMA_INTERRUPT, device->cap_mask))
 			device = NULL;
 
-		tx = device ? device->device_prep_dma_interrupt(chan) : NULL;
+		tx = device ? device->device_prep_dma_interrupt(chan, 0) : NULL;
 	} else
 		tx = NULL;
 
 	if (tx) {
 		pr_debug("%s: (async)\n", __func__);
 
-		async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
+		async_tx_submit(chan, tx, submit);
 	} else {
 		pr_debug("%s: (sync)\n", __func__);
 
 		/* wait for any prerequisite operations */
-		if (depend_tx) {
-			/* if ack is already set then we cannot be sure
-			 * we are referring to the correct operation
-			 */
-			BUG_ON(depend_tx->ack);
-			if (dma_wait_for_async_tx(depend_tx) == DMA_ERROR)
-				panic("%s: DMA_ERROR waiting for depend_tx\n",
-					__func__);
-		}
+		async_tx_quiesce(&submit->depend_tx);
 
-		async_tx_sync_epilog(flags, depend_tx, cb_fn, cb_param);
+		async_tx_sync_epilog(submit);
 	}
 
 	return tx;
 }
 EXPORT_SYMBOL_GPL(async_trigger_callback);
 
-module_init(async_tx_init);
-module_exit(async_tx_exit);
+/**
+ * async_tx_quiesce - ensure tx is complete and freeable upon return
+ * @tx - transaction to quiesce
+ */
+void async_tx_quiesce(struct dma_async_tx_descriptor **tx)
+{
+	if (*tx) {
+		/* if ack is already set then we cannot be sure
+		 * we are referring to the correct operation
+		 */
+		BUG_ON(async_tx_test_ack(*tx));
+		if (dma_wait_for_async_tx(*tx) != DMA_COMPLETE)
+			panic("%s: DMA error waiting for transaction\n",
+			      __func__);
+		async_tx_ack(*tx);
+		*tx = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(async_tx_quiesce);
 
 MODULE_AUTHOR("Intel Corporation");
 MODULE_DESCRIPTION("Asynchronous Bulk Memory Transactions API");