*
* Each device has a kref, which is initialized to 1 when the device is
* registered. A kref_get is done for each device registered. When the
- * device is released, the coresponding kref_put is done in the release
+ * device is released, the corresponding kref_put is done in the release
* method. Every time one of the device's channels is allocated to a client,
- * a kref_get occurs. When the channel is freed, the coresponding kref_put
+ * a kref_get occurs. When the channel is freed, the corresponding kref_put
* happens. The device's release function does a completion, so
* unregister_device does a remove event, device_unregister, a kref_put
* for the first reference, then waits on the completion for all other
* Each channel has an open-coded implementation of Rusty Russell's "bigref,"
* with a kref and a per_cpu local_t. A dma_chan_get is called when a client
* signals that it wants to use a channel, and dma_chan_put is called when
- * a channel is removed or a client using it is unregesitered. A client can
+ * a channel is removed or a client using it is unregistered. A client can
* take extra references per outstanding transaction, as is the case with
* the NET DMA client. The release function does a kref_put on the device.
* -ChrisL, DanW
enum dma_state_client ack;
/* Find a channel */
- list_for_each_entry(device, &dma_device_list, global_node)
+ list_for_each_entry(device, &dma_device_list, global_node) {
+ /* Does the client require a specific DMA controller? */
+ if (client->slave && client->slave->dma_dev
+ && client->slave->dma_dev != device->dev)
+ continue;
+
list_for_each_entry(chan, &device->channels, device_node) {
if (!dma_chan_satisfies_mask(chan, client->cap_mask))
continue;
- desc = chan->device->device_alloc_chan_resources(chan);
+ desc = chan->device->device_alloc_chan_resources(
+ chan, client);
if (desc >= 0) {
ack = client->event_callback(client,
chan,
/* we are done once this client rejects
* an available resource
*/
- if (ack == DMA_ACK)
+ if (ack == DMA_ACK) {
dma_chan_get(chan);
- else if (ack == DMA_NAK)
+ chan->client_count++;
+ } else if (ack == DMA_NAK)
return;
}
}
+ }
}
enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
/* client was holding resources for this channel so
* free it
*/
- if (ack == DMA_ACK)
+ if (ack == DMA_ACK) {
dma_chan_put(chan);
+ chan->client_count--;
+ }
}
mutex_unlock(&dma_list_mutex);
*/
void dma_async_client_register(struct dma_client *client)
{
+ /* validate client data */
+ BUG_ON(dma_has_cap(DMA_SLAVE, client->cap_mask) &&
+ !client->slave);
+
mutex_lock(&dma_list_mutex);
list_add_tail(&client->global_node, &dma_client_list);
mutex_unlock(&dma_list_mutex);
ack = client->event_callback(client, chan,
DMA_RESOURCE_REMOVED);
- if (ack == DMA_ACK)
+ if (ack == DMA_ACK) {
dma_chan_put(chan);
+ chan->client_count--;
+ }
}
list_del(&client->global_node);
!device->device_prep_dma_memset);
BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
!device->device_prep_dma_interrupt);
+ BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
+ !device->device_prep_slave_sg);
+ BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
+ !device->device_terminate_all);
BUG_ON(!device->device_alloc_chan_resources);
BUG_ON(!device->device_free_chan_resources);
- BUG_ON(!device->device_dependency_added);
BUG_ON(!device->device_is_tx_complete);
BUG_ON(!device->device_issue_pending);
BUG_ON(!device->dev);
init_completion(&device->done);
kref_init(&device->refcount);
+
+ mutex_lock(&dma_list_mutex);
device->dev_id = id++;
+ mutex_unlock(&dma_list_mutex);
/* represent channels in sysfs. Probably want devs too */
list_for_each_entry(chan, &device->channels, device_node) {
chan->chan_id = chancnt++;
chan->dev.class = &dma_devclass;
- chan->dev.parent = NULL;
- snprintf(chan->dev.bus_id, BUS_ID_SIZE, "dma%dchan%d",
- device->dev_id, chan->chan_id);
+ chan->dev.parent = device->dev;
+ dev_set_name(&chan->dev, "dma%dchan%d",
+ device->dev_id, chan->chan_id);
rc = device_register(&chan->dev);
if (rc) {
kref_get(&device->refcount);
kref_get(&device->refcount);
kref_init(&chan->refcount);
+ chan->client_count = 0;
chan->slow_ref = 0;
INIT_RCU_HEAD(&chan->rcu);
}
dma_src = dma_map_single(dev->dev, src, len, DMA_TO_DEVICE);
dma_dest = dma_map_single(dev->dev, dest, len, DMA_FROM_DEVICE);
- tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, 0);
+ tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len,
+ DMA_CTRL_ACK);
if (!tx) {
dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
return -ENOMEM;
}
- tx->ack = 1;
tx->callback = NULL;
cookie = tx->tx_submit(tx);
dma_src = dma_map_single(dev->dev, kdata, len, DMA_TO_DEVICE);
dma_dest = dma_map_page(dev->dev, page, offset, len, DMA_FROM_DEVICE);
- tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, 0);
+ tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len,
+ DMA_CTRL_ACK);
if (!tx) {
dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
return -ENOMEM;
}
- tx->ack = 1;
tx->callback = NULL;
cookie = tx->tx_submit(tx);
dma_src = dma_map_page(dev->dev, src_pg, src_off, len, DMA_TO_DEVICE);
dma_dest = dma_map_page(dev->dev, dest_pg, dest_off, len,
DMA_FROM_DEVICE);
- tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, 0);
+ tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len,
+ DMA_CTRL_ACK);
if (!tx) {
dma_unmap_page(dev->dev, dma_src, len, DMA_TO_DEVICE);
return -ENOMEM;
}
- tx->ack = 1;
tx->callback = NULL;
cookie = tx->tx_submit(tx);
{
tx->chan = chan;
spin_lock_init(&tx->lock);
- INIT_LIST_HEAD(&tx->depend_node);
- INIT_LIST_HEAD(&tx->depend_list);
}
EXPORT_SYMBOL(dma_async_tx_descriptor_init);
+/* dma_wait_for_async_tx - spin wait for a transaction to complete
+ * @tx: in-flight transaction to wait on
+ *
+ * This routine assumes that tx was obtained from a call to async_memcpy,
+ * async_xor, async_memset, etc which ensures that tx is "in-flight" (prepped
+ * and submitted). Walking the parent chain is only meant to cover for DMA
+ * drivers that do not implement the DMA_INTERRUPT capability and may race with
+ * the driver's descriptor cleanup routine.
+ */
+enum dma_status
+dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx)
+{
+ enum dma_status status;
+ struct dma_async_tx_descriptor *iter;
+ struct dma_async_tx_descriptor *parent;
+
+ if (!tx)
+ return DMA_SUCCESS;
+
+ WARN_ONCE(tx->parent, "%s: speculatively walking dependency chain for"
+ " %s\n", __func__, dev_name(&tx->chan->dev));
+
+ /* poll through the dependency chain, return when tx is complete */
+ do {
+ iter = tx;
+
+ /* find the root of the unsubmitted dependency chain */
+ do {
+ parent = iter->parent;
+ if (!parent)
+ break;
+ else
+ iter = parent;
+ } while (parent);
+
+ /* there is a small window for ->parent == NULL and
+ * ->cookie == -EBUSY
+ */
+ while (iter->cookie == -EBUSY)
+ cpu_relax();
+
+ status = dma_sync_wait(iter->chan, iter->cookie);
+ } while (status == DMA_IN_PROGRESS || (iter != tx));
+
+ return status;
+}
+EXPORT_SYMBOL_GPL(dma_wait_for_async_tx);
+
+/* dma_run_dependencies - helper routine for dma drivers to process
+ * (start) dependent operations on their target channel
+ * @tx: transaction with dependencies
+ */
+void dma_run_dependencies(struct dma_async_tx_descriptor *tx)
+{
+ struct dma_async_tx_descriptor *dep = tx->next;
+ struct dma_async_tx_descriptor *dep_next;
+ struct dma_chan *chan;
+
+ if (!dep)
+ return;
+
+ chan = dep->chan;
+
+ /* keep submitting up until a channel switch is detected
+ * in that case we will be called again as a result of
+ * 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;
+ if (dep_next && dep_next->chan == chan)
+ dep->next = NULL; /* ->next will be submitted */
+ else
+ dep_next = NULL; /* submit current dep and terminate */
+ spin_unlock_bh(&dep->lock);
+
+ dep->tx_submit(dep);
+ }
+
+ chan->device->device_issue_pending(chan);
+}
+EXPORT_SYMBOL_GPL(dma_run_dependencies);
+
static int __init dma_bus_init(void)
{
mutex_init(&dma_list_mutex);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff