/**
* async_tx_channel_switch - queue an interrupt descriptor with a dependency
* pre-attached.
* @depend_tx: the operation that must finish before the new operation runs
* @tx: the new operation
*/
static void
async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx,
struct dma_async_tx_descriptor *tx)
{
struct dma_chan *chan = depend_tx->chan;
struct dma_device *device = chan->device;
struct dma_async_tx_descriptor *intr_tx = (void *) ~0;
/* first check to see if we can still append to depend_tx */
txd_lock(depend_tx);
if (txd_parent(depend_tx) && depend_tx->chan == tx->chan) {
txd_chain(depend_tx, tx);
intr_tx = NULL;
}
txd_unlock(depend_tx);
/* attached dependency, flush the parent channel */
if (!intr_tx) {
device->device_issue_pending(chan);
return;
}
/* see if we can schedule an interrupt
* otherwise poll for completion
*/
if (dma_has_cap(DMA_INTERRUPT, device->cap_mask))
intr_tx = device->device_prep_dma_interrupt(chan, 0);
else
intr_tx = NULL;
if (intr_tx) {
intr_tx->callback = NULL;
intr_tx->callback_param = NULL;
/* safe to chain outside the lock since we know we are
* not submitted yet
*/
txd_chain(intr_tx, tx);
/* check if we need to append */
txd_lock(depend_tx);
if (txd_parent(depend_tx)) {
txd_chain(depend_tx, intr_tx);
async_tx_ack(intr_tx);
intr_tx = NULL;
}
txd_unlock(depend_tx);
if (intr_tx) {
txd_clear_parent(intr_tx);
intr_tx->tx_submit(intr_tx);
async_tx_ack(intr_tx);
}
device->device_issue_pending(chan);
} else {
if (dma_wait_for_async_tx(depend_tx) != DMA_COMPLETE)
panic("%s: DMA error waiting for depend_tx\n",
__func__);
tx->tx_submit(tx);
}
}
static void
async_tx_channel_switch(struct dma_async_tx_descriptor *depend_tx,
struct dma_async_tx_descriptor *tx)
{
struct dma_chan *chan = depend_tx->chan;
struct dma_device *device = chan->device;
struct dma_async_tx_descriptor *intr_tx = (void *) ~0;
txd_lock(depend_tx);
if (txd_parent(depend_tx) && depend_tx->chan == tx->chan) {
txd_chain(depend_tx, tx);
intr_tx = NULL;
}
txd_unlock(depend_tx);
if (!intr_tx) {
device->device_issue_pending(chan);
return;
}
if (dma_has_cap(DMA_INTERRUPT, device->cap_mask))
intr_tx = device->device_prep_dma_interrupt(chan, 0);
else
intr_tx = NULL;
if (intr_tx) {
intr_tx->callback = NULL;
intr_tx->callback_param = NULL;
txd_chain(intr_tx, tx);
txd_lock(depend_tx);
if (txd_parent(depend_tx)) {
txd_chain(depend_tx, intr_tx);
async_tx_ack(intr_tx);
intr_tx = NULL;
}
txd_unlock(depend_tx);
if (intr_tx) {
txd_clear_parent(intr_tx);
intr_tx->tx_submit(intr_tx);
async_tx_ack(intr_tx);
}
device->device_issue_pending(chan);
} else {
if (dma_wait_for_async_tx(depend_tx) == DMA_ERROR)
panic("%s: DMA_ERROR waiting for depend_tx\n",
__func__);
tx->tx_submit(tx);
}
}
void
async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx,
struct async_submit_ctl *submit)
{
struct dma_async_tx_descriptor *depend_tx = submit->depend_tx;
tx->callback = submit->cb_fn;
tx->callback_param = submit->cb_param;
if (depend_tx) {
enum submit_disposition s;
BUG_ON(async_tx_test_ack(depend_tx) || txd_next(depend_tx) ||
txd_parent(tx));
txd_lock(depend_tx);
if (txd_parent(depend_tx)) {
if (depend_tx->chan == chan) {
txd_chain(depend_tx, tx);
s = ASYNC_TX_SUBMITTED;
} else
s = ASYNC_TX_CHANNEL_SWITCH;
} else {
if (depend_tx->chan == chan)
s = ASYNC_TX_DIRECT_SUBMIT;
else
s = ASYNC_TX_CHANNEL_SWITCH;
}
txd_unlock(depend_tx);
switch (s) {
case ASYNC_TX_SUBMITTED:
break;
case ASYNC_TX_CHANNEL_SWITCH:
async_tx_channel_switch(depend_tx, tx);
break;
case ASYNC_TX_DIRECT_SUBMIT:
txd_clear_parent(tx);
tx->tx_submit(tx);
break;
}
} else {
txd_clear_parent(tx);
tx->tx_submit(tx);
}
if (submit->flags & ASYNC_TX_ACK)
async_tx_ack(tx);
if (depend_tx)
async_tx_ack(depend_tx);
}
void
async_tx_submit(struct dma_chan *chan, struct dma_async_tx_descriptor *tx,
struct async_submit_ctl *submit)
{
struct dma_async_tx_descriptor *depend_tx = submit->depend_tx;
tx->callback = submit->cb_fn;
tx->callback_param = submit->cb_param;
if (depend_tx) {
enum submit_disposition s;
/* sanity check the dependency chain:
* 1/ if ack is already set then we cannot be sure
* we are referring to the correct operation
* 2/ dependencies are 1:1 i.e. two transactions can
* not depend on the same 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
*/
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) {
txd_chain(depend_tx, tx);
s = ASYNC_TX_SUBMITTED;
} else
s = ASYNC_TX_CHANNEL_SWITCH;
} else {
/* we do not have a parent so we may be able to submit
* directly if we are staying on the same channel
*/
if (depend_tx->chan == chan)
s = ASYNC_TX_DIRECT_SUBMIT;
else
s = ASYNC_TX_CHANNEL_SWITCH;
}
txd_unlock(depend_tx);
switch (s) {
case ASYNC_TX_SUBMITTED:
break;
case ASYNC_TX_CHANNEL_SWITCH:
async_tx_channel_switch(depend_tx, tx);
break;
case ASYNC_TX_DIRECT_SUBMIT:
txd_clear_parent(tx);
tx->tx_submit(tx);
break;
}
} else {
txd_clear_parent(tx);
tx->tx_submit(tx);
}
if (submit->flags & ASYNC_TX_ACK)
async_tx_ack(tx);
if (depend_tx)
async_tx_ack(depend_tx);
}
