From 209b84a88fe81341b4d8d465acc4a67cb7c3feb3 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Tue, 6 Jan 2009 11:38:17 -0700 Subject: [PATCH] dmaengine: replace dma_async_client_register with dmaengine_get Now that clients no longer need to be notified of channel arrival dma_async_client_register can simply increment the dmaengine_ref_count. Reviewed-by: Andrew Morton Signed-off-by: Dan Williams --- crypto/async_tx/async_tx.c | 115 +------------------------------------ drivers/dma/dmaengine.c | 22 ++----- include/linux/dmaengine.h | 4 +- net/core/dev.c | 3 +- 4 files changed, 11 insertions(+), 133 deletions(-) diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c index 2cdf7a0867b7..f21147f3626a 100644 --- a/crypto/async_tx/async_tx.c +++ b/crypto/async_tx/async_tx.c @@ -28,120 +28,9 @@ #include #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 */ -}; - -/** - * async_tx_lock - protect modification of async_tx_master_list and serialize - * rebalance operations - */ -static DEFINE_SPINLOCK(async_tx_lock); - -static LIST_HEAD(async_tx_master_list); - -static void -free_dma_chan_ref(struct rcu_head *rcu) -{ - struct dma_chan_ref *ref; - ref = container_of(rcu, struct dma_chan_ref, rcu); - kfree(ref); -} - -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); -} - -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) { - 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; - } - break; - case DMA_RESOURCE_REMOVED: - found = 0; - spin_lock_irqsave(&async_tx_lock, flags); - list_for_each_entry(ref, &async_tx_master_list, node) - if (ref->chan == 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; - 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) { - dma_async_client_register(&async_tx_dma); - dma_async_client_chan_request(&async_tx_dma); + dmaengine_get(); printk(KERN_INFO "async_tx: api initialized (async)\n"); @@ -150,7 +39,7 @@ static int __init async_tx_init(void) static void __exit async_tx_exit(void) { - dma_async_client_unregister(&async_tx_dma); + dmaengine_put(); } /** diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 90aca505a1df..3f1849b7f5ef 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -600,10 +600,9 @@ static void dma_clients_notify_available(void) } /** - * dma_async_client_register - register a &dma_client - * @client: ptr to a client structure with valid 'event_callback' and 'cap_mask' + * dmaengine_get - register interest in dma_channels */ -void dma_async_client_register(struct dma_client *client) +void dmaengine_get(void) { struct dma_device *device, *_d; struct dma_chan *chan; @@ -634,25 +633,18 @@ void dma_async_client_register(struct dma_client *client) */ if (dmaengine_ref_count == 1) dma_channel_rebalance(); - list_add_tail(&client->global_node, &dma_client_list); mutex_unlock(&dma_list_mutex); } -EXPORT_SYMBOL(dma_async_client_register); +EXPORT_SYMBOL(dmaengine_get); /** - * 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_put - let dma drivers be removed when ref_count == 0 */ -void dma_async_client_unregister(struct dma_client *client) +void dmaengine_put(void) { struct dma_device *device; struct dma_chan *chan; - if (!client) - return; - mutex_lock(&dma_list_mutex); dmaengine_ref_count--; BUG_ON(dmaengine_ref_count < 0); @@ -663,11 +655,9 @@ void dma_async_client_unregister(struct dma_client *client) list_for_each_entry(chan, &device->channels, device_node) dma_chan_put(chan); } - - list_del(&client->global_node); mutex_unlock(&dma_list_mutex); } -EXPORT_SYMBOL(dma_async_client_unregister); +EXPORT_SYMBOL(dmaengine_put); /** * dma_async_client_chan_request - send all available channels to the diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h index d63544cf8a1a..37d95db156d3 100644 --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -318,8 +318,8 @@ struct dma_device { /* --- public DMA engine API --- */ -void dma_async_client_register(struct dma_client *client); -void dma_async_client_unregister(struct dma_client *client); +void dmaengine_get(void); +void dmaengine_put(void); void dma_async_client_chan_request(struct dma_client *client); dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest, void *src, size_t len); diff --git a/net/core/dev.c b/net/core/dev.c index bbb07dbe1740..7596fc9403c8 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -4894,8 +4894,7 @@ static int __init netdev_dma_register(void) } spin_lock_init(&net_dma.lock); dma_cap_set(DMA_MEMCPY, net_dma.client.cap_mask); - dma_async_client_register(&net_dma.client); - dma_async_client_chan_request(&net_dma.client); + dmaengine_get(); return 0; }