/**
* dma_chan_get - try to grab a dma channel's parent driver module
* @chan - channel to grab
*
* Must be called under dma_list_mutex
*/
static int dma_chan_get(struct dma_chan *chan)
{
struct module *owner = dma_chan_to_owner(chan);
int ret;
/* The channel is already in use, update client count */
if (chan->client_count) {
__module_get(owner);
goto out;
}
if (!try_module_get(owner))
return -ENODEV;
/* allocate upon first client reference */
if (chan->device->device_alloc_chan_resources) {
ret = chan->device->device_alloc_chan_resources(chan);
if (ret < 0)
goto err_out;
}
if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
balance_ref_count(chan);
out:
chan->client_count++;
return 0;
err_out:
module_put(owner);
return ret;
}
/**
* dma_chan_get - try to grab a dma channel's parent driver module
* @chan - channel to grab
*
* Must be called under dma_list_mutex
*/
static int dma_chan_get(struct dma_chan *chan)
{
int err = -ENODEV;
struct module *owner = dma_chan_to_owner(chan);
if (chan->client_count) {
__module_get(owner);
err = 0;
} else if (try_module_get(owner))
err = 0;
if (err == 0)
chan->client_count++;
/* allocate upon first client reference */
if (chan->client_count == 1 && err == 0) {
int desc_cnt = chan->device->device_alloc_chan_resources(chan);
if (desc_cnt < 0) {
err = desc_cnt;
chan->client_count = 0;
module_put(owner);
} else if (!dma_has_cap(DMA_PRIVATE, chan->device->cap_mask))
balance_ref_count(chan);
}
return err;
}
struct dma_async_tx_descriptor *
async_trigger_callback(struct async_submit_ctl *submit)
{
struct dma_chan *chan;
struct dma_device *device;
struct dma_async_tx_descriptor *tx;
struct dma_async_tx_descriptor *depend_tx = submit->depend_tx;
if (depend_tx) {
chan = depend_tx->chan;
device = chan->device;
if (device && !dma_has_cap(DMA_INTERRUPT, device->cap_mask))
device = NULL;
tx = device ? device->device_prep_dma_interrupt(chan, 0) : NULL;
} else
tx = NULL;
if (tx) {
pr_debug("%s: (async)\n", __func__);
async_tx_submit(chan, tx, submit);
} else {
pr_debug("%s: (sync)\n", __func__);
async_tx_quiesce(&submit->depend_tx);
async_tx_sync_epilog(submit);
}
return tx;
}
/**
* 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);
}
}
/**
* __async_tx_find_channel - find a channel to carry out the operation or let
* the transaction execute synchronously
* @depend_tx: transaction dependency
* @tx_type: transaction type
*/
struct dma_chan *
__async_tx_find_channel(struct dma_async_tx_descriptor *depend_tx,
enum dma_transaction_type tx_type)
{
/* see if we can keep the chain on one channel */
if (depend_tx &&
dma_has_cap(tx_type, depend_tx->chan->device->cap_mask))
return depend_tx->chan;
return dma_find_channel(tx_type);
}
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);
}
}
struct dma_chan *
__async_tx_find_channel(struct async_submit_ctl *submit,
enum dma_transaction_type tx_type)
{
struct dma_async_tx_descriptor *depend_tx = submit->depend_tx;
if (depend_tx &&
dma_has_cap(tx_type, depend_tx->chan->device->cap_mask))
return depend_tx->chan;
return async_dma_find_channel(tx_type);
}
/**
* async_trigger_callback - schedules the callback function to be run after
* any dependent operations have been completed.
* @flags: ASYNC_TX_ACK, ASYNC_TX_DEP_ACK
* @depend_tx: 'callback' requires the completion of this transaction
* @cb_fn: function to call after depend_tx completes
* @cb_param: parameter to pass to the callback routine
*/
struct dma_async_tx_descriptor *
async_trigger_callback(enum async_tx_flags flags,
struct dma_async_tx_descriptor *depend_tx,
dma_async_tx_callback cb_fn, void *cb_param)
{
struct dma_chan *chan;
struct dma_device *device;
struct dma_async_tx_descriptor *tx;
if (depend_tx) {
chan = depend_tx->chan;
device = chan->device;
/* see if we can schedule an interrupt
* otherwise poll for completion
*/
if (device && !dma_has_cap(DMA_INTERRUPT, device->cap_mask))
device = NULL;
tx = device ? device->device_prep_dma_interrupt(chan, 0) : NULL;
} else
tx = NULL;
if (tx) {
pr_debug("%s: (async)\n", __func__);
async_tx_submit(chan, tx, flags, depend_tx, cb_fn, cb_param);
} else {
pr_debug("%s: (sync)\n", __func__);
/* wait for any prerequisite operations */
async_tx_quiesce(&depend_tx);
async_tx_sync_epilog(cb_fn, cb_param);
}
return tx;
}
/**
* 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;
struct dma_device *device;
struct dma_async_tx_descriptor *intr_tx = (void *) ~0;
/* 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;
intr_tx = NULL;
}
spin_unlock_bh(&depend_tx->lock);
if (!intr_tx)
return;
chan = depend_tx->chan;
device = chan->device;
/* 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;
tx->parent = intr_tx;
/* safe to set ->next outside the lock since we know we are
* not submitted yet
*/
intr_tx->next = 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;
async_tx_ack(intr_tx);
intr_tx = NULL;
}
spin_unlock_bh(&depend_tx->lock);
if (intr_tx) {
intr_tx->parent = NULL;
intr_tx->tx_submit(intr_tx);
async_tx_ack(intr_tx);
}
} 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);
}
}
