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Date: Fri, 14 Nov 2008 14:35:08 -0700
From: Dan Williams <dan.j.williams@...el.com>
To: linux-kernel@...r.kernel.org, netdev@...r.kernel.org
Cc: maciej.sosnowski@...el.com, hskinnemoen@...el.com,
g.liakhovetski@....de, nicolas.ferre@...el.com
Subject: [PATCH 10/13] 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.
Signed-off-by: Dan Williams <dan.j.williams@...el.com>
---
crypto/async_tx/async_tx.c | 115 +-------------------------------------------
drivers/dma/dmaengine.c | 23 ++-------
include/linux/dmaengine.h | 4 +-
net/core/dev.c | 3 -
4 files changed, 11 insertions(+), 134 deletions(-)
diff --git a/crypto/async_tx/async_tx.c b/crypto/async_tx/async_tx.c
index 2cdf7a0..f21147f 100644
--- a/crypto/async_tx/async_tx.c
+++ b/crypto/async_tx/async_tx.c
@@ -28,120 +28,9 @@
#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 */
-};
-
-/**
- * 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 1b694b8..78456f5 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -588,10 +588,9 @@ 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;
@@ -615,26 +614,18 @@ void dma_async_client_register(struct dma_client *client)
dev_name(&chan->dev), err);
}
}
-
- 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);
@@ -645,11 +636,9 @@ 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 d63544c..37d95db 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 56e6965..4b3b7d3 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4657,8 +4657,7 @@ 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;
}
--
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