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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
Download patch file Download diff file Expand all files Collapse all files

46
crypto/async_tx/async_tx.c
View file

@ -81,18 +81,13 @@ async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx,
struct dma_device *device = chan->device;
struct dma_async_tx_descriptor *intr_tx = (void *) ~0;
#ifdef CONFIG_ASYNC_TX_DISABLE_CHANNEL_SWITCH
BUG();
#endif
/* first check to see if we can still append to depend_tx */
spin_lock_bh(&depend_tx->lock);
if (depend_tx->parent && depend_tx->chan == tx->chan) {
tx->parent = depend_tx;
depend_tx->next = tx;
txd_lock(depend_tx);
if (txd_parent(depend_tx) && depend_tx->chan == tx->chan) {
txd_chain(depend_tx, tx);
intr_tx = NULL;
}
spin_unlock_bh(&depend_tx->lock);
txd_unlock(depend_tx);
/* attached dependency, flush the parent channel */
if (!intr_tx) {
@ -111,24 +106,22 @@ async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx,
if (intr_tx) {
intr_tx->callback = NULL;
intr_tx->callback_param = NULL;
tx->parent = intr_tx;
/* safe to set ->next outside the lock since we know we are
/* safe to chain outside the lock since we know we are
* not submitted yet
*/
intr_tx->next = tx;
txd_chain(intr_tx, tx);
/* check if we need to append */
spin_lock_bh(&depend_tx->lock);
if (depend_tx->parent) {
intr_tx->parent = depend_tx;
depend_tx->next = intr_tx;
txd_lock(depend_tx);
if (txd_parent(depend_tx)) {
txd_chain(depend_tx, intr_tx);
async_tx_ack(intr_tx);
intr_tx = NULL;
}
spin_unlock_bh(&depend_tx->lock);
txd_unlock(depend_tx);
if (intr_tx) {
intr_tx->parent = NULL;
txd_clear_parent(intr_tx);
intr_tx->tx_submit(intr_tx);
async_tx_ack(intr_tx);
}
@ -176,21 +169,20 @@ async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx,
* 2/ dependencies are 1:1 i.e. two transactions can
* not depend on the same parent
*/
BUG_ON(async_tx_test_ack(depend_tx) || depend_tx->next ||
tx->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
*/
spin_lock_bh(&depend_tx->lock);
if (depend_tx->parent) {
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) {
tx->parent = depend_tx;
depend_tx->next = tx;
txd_chain(depend_tx, tx);
s = ASYNC_TX_SUBMITTED;
} else
s = ASYNC_TX_CHANNEL_SWITCH;
@ -203,7 +195,7 @@ async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx,
else
s = ASYNC_TX_CHANNEL_SWITCH;
}
spin_unlock_bh(&depend_tx->lock);
txd_unlock(depend_tx);
switch (s) {
case ASYNC_TX_SUBMITTED:
@ -212,12 +204,12 @@ async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx,
async_tx_channel_switch(depend_tx, tx);
break;
case ASYNC_TX_DIRECT_SUBMIT:
tx->parent = NULL;
txd_clear_parent(tx);
tx->tx_submit(tx);
break;
}
} else {
tx->parent = NULL;
txd_clear_parent(tx);
tx->tx_submit(tx);
}