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async_tx: trim dma_async_tx_descriptor in 'no channel switch' case

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Saves 24 bytes per descriptor (64-bit) when the channel-switching
capabilities of async_tx are not required.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
This commit is contained in:
Dan Williams
2010-05-17 16:24:16 -07:00
parent c86e1401c9
commit caa20d974c
3 changed files with 88 additions and 34 deletions
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16
drivers/dma/dmaengine.c
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@@ -978,7 +978,9 @@ void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
struct dma_chan *chan)
{
tx->chan = chan;
#ifndef CONFIG_ASYNC_TX_DISABLE_CHANNEL_SWITCH
spin_lock_init(&tx->lock);
#endif
}
EXPORT_SYMBOL(dma_async_tx_descriptor_init);
@@ -1011,7 +1013,7 @@ EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
*/
void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
{
struct dma_async_tx_descriptor *dep = tx->next;
struct dma_async_tx_descriptor *dep = txd_next(tx);
struct dma_async_tx_descriptor *dep_next;
struct dma_chan *chan;
@@ -1019,7 +1021,7 @@ void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
return;
/* we'll submit tx->next now, so clear the link */
tx->next = NULL;
txd_clear_next(tx);
chan = dep->chan;
/* keep submitting up until a channel switch is detected
@@ -1027,14 +1029,14 @@ void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
* 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;
txd_lock(dep);
txd_clear_parent(dep);
dep_next = txd_next(dep);
if (dep_next && dep_next->chan == chan)
dep->next = NULL; /* ->next will be submitted */
txd_clear_next(dep); /* ->next will be submitted */
else
dep_next = NULL; /* submit current dep and terminate */
spin_unlock_bh(&dep->lock);
txd_unlock(dep);
dep->tx_submit(dep);
}