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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 <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams 2009-01-06 11:38:17 -07:00
parent 74465b4ff9
commit 209b84a88f
4 changed files with 11 additions and 133 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

115
crypto/async_tx/async_tx.c
View File

@ -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();
}
/**

22
drivers/dma/dmaengine.c
View File

@ -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

4
include/linux/dmaengine.h
View File

@ -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);

3
net/core/dev.c
View File

@ -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;
}