diff options
Diffstat (limited to 'drivers/dma/dmaengine.c')
| -rw-r--r-- | drivers/dma/dmaengine.c | 1261 |
1 files changed, 958 insertions, 303 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 8db0e7f9d3f..d5d30ed863c 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -31,34 +31,23 @@ * * LOCKING: * - * The subsystem keeps two global lists, dma_device_list and dma_client_list. - * Both of these are protected by a mutex, dma_list_mutex. + * The subsystem keeps a global list of dma_device structs it is protected by a + * mutex, dma_list_mutex. + * + * A subsystem can get access to a channel by calling dmaengine_get() followed + * by dma_find_channel(), or if it has need for an exclusive channel it can call + * dma_request_channel(). Once a channel is allocated a reference is taken + * against its corresponding driver to disable removal. * * Each device has a channels list, which runs unlocked but is never modified * once the device is registered, it's just setup by the driver. * - * Each client is responsible for keeping track of the channels it uses. See - * the definition of dma_event_callback in dmaengine.h. - * - * 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 - * 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 - * 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 - * references to finish. - * - * 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 - * 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 + * See Documentation/dmaengine.txt for more details */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/dma-mapping.h> #include <linux/init.h> #include <linux/module.h> #include <linux/mm.h> @@ -70,125 +59,210 @@ #include <linux/rcupdate.h> #include <linux/mutex.h> #include <linux/jiffies.h> +#include <linux/rculist.h> +#include <linux/idr.h> +#include <linux/slab.h> +#include <linux/acpi.h> +#include <linux/acpi_dma.h> +#include <linux/of_dma.h> +#include <linux/mempool.h> static DEFINE_MUTEX(dma_list_mutex); +static DEFINE_IDR(dma_idr); static LIST_HEAD(dma_device_list); -static LIST_HEAD(dma_client_list); +static long dmaengine_ref_count; /* --- sysfs implementation --- */ -static ssize_t show_memcpy_count(struct device *dev, struct device_attribute *attr, char *buf) +/** + * dev_to_dma_chan - convert a device pointer to the its sysfs container object + * @dev - device node + * + * Must be called under dma_list_mutex + */ +static struct dma_chan *dev_to_dma_chan(struct device *dev) +{ + struct dma_chan_dev *chan_dev; + + chan_dev = container_of(dev, typeof(*chan_dev), device); + return chan_dev->chan; +} + +static ssize_t memcpy_count_show(struct device *dev, + struct device_attribute *attr, char *buf) { - struct dma_chan *chan = to_dma_chan(dev); + struct dma_chan *chan; unsigned long count = 0; int i; + int err; - for_each_possible_cpu(i) - count += per_cpu_ptr(chan->local, i)->memcpy_count; + mutex_lock(&dma_list_mutex); + chan = dev_to_dma_chan(dev); + if (chan) { + for_each_possible_cpu(i) + count += per_cpu_ptr(chan->local, i)->memcpy_count; + err = sprintf(buf, "%lu\n", count); + } else + err = -ENODEV; + mutex_unlock(&dma_list_mutex); - return sprintf(buf, "%lu\n", count); + return err; } +static DEVICE_ATTR_RO(memcpy_count); -static ssize_t show_bytes_transferred(struct device *dev, struct device_attribute *attr, - char *buf) +static ssize_t bytes_transferred_show(struct device *dev, + struct device_attribute *attr, char *buf) { - struct dma_chan *chan = to_dma_chan(dev); + struct dma_chan *chan; unsigned long count = 0; int i; + int err; - for_each_possible_cpu(i) - count += per_cpu_ptr(chan->local, i)->bytes_transferred; + mutex_lock(&dma_list_mutex); + chan = dev_to_dma_chan(dev); + if (chan) { + for_each_possible_cpu(i) + count += per_cpu_ptr(chan->local, i)->bytes_transferred; + err = sprintf(buf, "%lu\n", count); + } else + err = -ENODEV; + mutex_unlock(&dma_list_mutex); - return sprintf(buf, "%lu\n", count); + return err; } +static DEVICE_ATTR_RO(bytes_transferred); -static ssize_t show_in_use(struct device *dev, struct device_attribute *attr, char *buf) +static ssize_t in_use_show(struct device *dev, struct device_attribute *attr, + char *buf) { - struct dma_chan *chan = to_dma_chan(dev); - int in_use = 0; + struct dma_chan *chan; + int err; - if (unlikely(chan->slow_ref) && - atomic_read(&chan->refcount.refcount) > 1) - in_use = 1; - else { - if (local_read(&(per_cpu_ptr(chan->local, - get_cpu())->refcount)) > 0) - in_use = 1; - put_cpu(); - } + mutex_lock(&dma_list_mutex); + chan = dev_to_dma_chan(dev); + if (chan) + err = sprintf(buf, "%d\n", chan->client_count); + else + err = -ENODEV; + mutex_unlock(&dma_list_mutex); - return sprintf(buf, "%d\n", in_use); + return err; } +static DEVICE_ATTR_RO(in_use); -static struct device_attribute dma_attrs[] = { - __ATTR(memcpy_count, S_IRUGO, show_memcpy_count, NULL), - __ATTR(bytes_transferred, S_IRUGO, show_bytes_transferred, NULL), - __ATTR(in_use, S_IRUGO, show_in_use, NULL), - __ATTR_NULL +static struct attribute *dma_dev_attrs[] = { + &dev_attr_memcpy_count.attr, + &dev_attr_bytes_transferred.attr, + &dev_attr_in_use.attr, + NULL, }; +ATTRIBUTE_GROUPS(dma_dev); -static void dma_async_device_cleanup(struct kref *kref); - -static void dma_dev_release(struct device *dev) +static void chan_dev_release(struct device *dev) { - struct dma_chan *chan = to_dma_chan(dev); - kref_put(&chan->device->refcount, dma_async_device_cleanup); + struct dma_chan_dev *chan_dev; + + chan_dev = container_of(dev, typeof(*chan_dev), device); + if (atomic_dec_and_test(chan_dev->idr_ref)) { + mutex_lock(&dma_list_mutex); + idr_remove(&dma_idr, chan_dev->dev_id); + mutex_unlock(&dma_list_mutex); + kfree(chan_dev->idr_ref); + } + kfree(chan_dev); } static struct class dma_devclass = { .name = "dma", - .dev_attrs = dma_attrs, - .dev_release = dma_dev_release, + .dev_groups = dma_dev_groups, + .dev_release = chan_dev_release, }; /* --- client and device registration --- */ -#define dma_chan_satisfies_mask(chan, mask) \ - __dma_chan_satisfies_mask((chan), &(mask)) +#define dma_device_satisfies_mask(device, mask) \ + __dma_device_satisfies_mask((device), &(mask)) static int -__dma_chan_satisfies_mask(struct dma_chan *chan, dma_cap_mask_t *want) +__dma_device_satisfies_mask(struct dma_device *device, + const dma_cap_mask_t *want) { dma_cap_mask_t has; - bitmap_and(has.bits, want->bits, chan->device->cap_mask.bits, + bitmap_and(has.bits, want->bits, device->cap_mask.bits, DMA_TX_TYPE_END); return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END); } +static struct module *dma_chan_to_owner(struct dma_chan *chan) +{ + return chan->device->dev->driver->owner; +} + /** - * dma_client_chan_alloc - try to allocate channels to a client - * @client: &dma_client + * balance_ref_count - catch up the channel reference count + * @chan - channel to balance ->client_count versus dmaengine_ref_count * - * Called with dma_list_mutex held. + * balance_ref_count must be called under dma_list_mutex */ -static void dma_client_chan_alloc(struct dma_client *client) +static void balance_ref_count(struct dma_chan *chan) { - struct dma_device *device; - struct dma_chan *chan; - int desc; /* allocated descriptor count */ - enum dma_state_client ack; + struct module *owner = dma_chan_to_owner(chan); - /* Find a channel */ - list_for_each_entry(device, &dma_device_list, global_node) - list_for_each_entry(chan, &device->channels, device_node) { - if (!dma_chan_satisfies_mask(chan, client->cap_mask)) - continue; + while (chan->client_count < dmaengine_ref_count) { + __module_get(owner); + chan->client_count++; + } +} - desc = chan->device->device_alloc_chan_resources(chan); - if (desc >= 0) { - ack = client->event_callback(client, - chan, - DMA_RESOURCE_AVAILABLE); +/** + * 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); + } - /* we are done once this client rejects - * an available resource - */ - if (ack == DMA_ACK) - dma_chan_get(chan); - else if (ack == DMA_NAK) - return; - } - } + return err; +} + +/** + * dma_chan_put - drop a reference to a dma channel's parent driver module + * @chan - channel to release + * + * Must be called under dma_list_mutex + */ +static void dma_chan_put(struct dma_chan *chan) +{ + if (!chan->client_count) + return; /* this channel failed alloc_chan_resources */ + chan->client_count--; + module_put(dma_chan_to_owner(chan)); + if (chan->client_count == 0) + chan->device->device_free_chan_resources(chan); } enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie) @@ -200,140 +274,513 @@ enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie) do { status = dma_async_is_tx_complete(chan, cookie, NULL, NULL); if (time_after_eq(jiffies, dma_sync_wait_timeout)) { - printk(KERN_ERR "dma_sync_wait_timeout!\n"); + pr_err("%s: timeout!\n", __func__); return DMA_ERROR; } - } while (status == DMA_IN_PROGRESS); + if (status != DMA_IN_PROGRESS) + break; + cpu_relax(); + } while (1); return status; } EXPORT_SYMBOL(dma_sync_wait); /** - * dma_chan_cleanup - release a DMA channel's resources - * @kref: kernel reference structure that contains the DMA channel device + * dma_cap_mask_all - enable iteration over all operation types + */ +static dma_cap_mask_t dma_cap_mask_all; + +/** + * dma_chan_tbl_ent - tracks channel allocations per core/operation + * @chan - associated channel for this entry + */ +struct dma_chan_tbl_ent { + struct dma_chan *chan; +}; + +/** + * channel_table - percpu lookup table for memory-to-memory offload providers */ -void dma_chan_cleanup(struct kref *kref) +static struct dma_chan_tbl_ent __percpu *channel_table[DMA_TX_TYPE_END]; + +static int __init dma_channel_table_init(void) { - struct dma_chan *chan = container_of(kref, struct dma_chan, refcount); - chan->device->device_free_chan_resources(chan); - kref_put(&chan->device->refcount, dma_async_device_cleanup); + enum dma_transaction_type cap; + int err = 0; + + bitmap_fill(dma_cap_mask_all.bits, DMA_TX_TYPE_END); + + /* 'interrupt', 'private', and 'slave' are channel capabilities, + * but are not associated with an operation so they do not need + * an entry in the channel_table + */ + clear_bit(DMA_INTERRUPT, dma_cap_mask_all.bits); + clear_bit(DMA_PRIVATE, dma_cap_mask_all.bits); + clear_bit(DMA_SLAVE, dma_cap_mask_all.bits); + + for_each_dma_cap_mask(cap, dma_cap_mask_all) { + channel_table[cap] = alloc_percpu(struct dma_chan_tbl_ent); + if (!channel_table[cap]) { + err = -ENOMEM; + break; + } + } + + if (err) { + pr_err("initialization failure\n"); + for_each_dma_cap_mask(cap, dma_cap_mask_all) + if (channel_table[cap]) + free_percpu(channel_table[cap]); + } + + return err; } -EXPORT_SYMBOL(dma_chan_cleanup); +arch_initcall(dma_channel_table_init); -static void dma_chan_free_rcu(struct rcu_head *rcu) +/** + * dma_find_channel - find a channel to carry out the operation + * @tx_type: transaction type + */ +struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type) { - struct dma_chan *chan = container_of(rcu, struct dma_chan, rcu); - int bias = 0x7FFFFFFF; - int i; - for_each_possible_cpu(i) - bias -= local_read(&per_cpu_ptr(chan->local, i)->refcount); - atomic_sub(bias, &chan->refcount.refcount); - kref_put(&chan->refcount, dma_chan_cleanup); + return this_cpu_read(channel_table[tx_type]->chan); } +EXPORT_SYMBOL(dma_find_channel); -static void dma_chan_release(struct dma_chan *chan) +/* + * net_dma_find_channel - find a channel for net_dma + * net_dma has alignment requirements + */ +struct dma_chan *net_dma_find_channel(void) { - atomic_add(0x7FFFFFFF, &chan->refcount.refcount); - chan->slow_ref = 1; - call_rcu(&chan->rcu, dma_chan_free_rcu); + struct dma_chan *chan = dma_find_channel(DMA_MEMCPY); + if (chan && !is_dma_copy_aligned(chan->device, 1, 1, 1)) + return NULL; + + return chan; } +EXPORT_SYMBOL(net_dma_find_channel); /** - * dma_chans_notify_available - broadcast available channels to the clients + * dma_issue_pending_all - flush all pending operations across all channels */ -static void dma_clients_notify_available(void) +void dma_issue_pending_all(void) { - struct dma_client *client; + struct dma_device *device; + struct dma_chan *chan; - mutex_lock(&dma_list_mutex); + rcu_read_lock(); + list_for_each_entry_rcu(device, &dma_device_list, global_node) { + if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) + continue; + list_for_each_entry(chan, &device->channels, device_node) + if (chan->client_count) + device->device_issue_pending(chan); + } + rcu_read_unlock(); +} +EXPORT_SYMBOL(dma_issue_pending_all); + +/** + * dma_chan_is_local - returns true if the channel is in the same numa-node as the cpu + */ +static bool dma_chan_is_local(struct dma_chan *chan, int cpu) +{ + int node = dev_to_node(chan->device->dev); + return node == -1 || cpumask_test_cpu(cpu, cpumask_of_node(node)); +} - list_for_each_entry(client, &dma_client_list, global_node) - dma_client_chan_alloc(client); +/** + * min_chan - returns the channel with min count and in the same numa-node as the cpu + * @cap: capability to match + * @cpu: cpu index which the channel should be close to + * + * If some channels are close to the given cpu, the one with the lowest + * reference count is returned. Otherwise, cpu is ignored and only the + * reference count is taken into account. + * Must be called under dma_list_mutex. + */ +static struct dma_chan *min_chan(enum dma_transaction_type cap, int cpu) +{ + struct dma_device *device; + struct dma_chan *chan; + struct dma_chan *min = NULL; + struct dma_chan *localmin = NULL; - mutex_unlock(&dma_list_mutex); + list_for_each_entry(device, &dma_device_list, global_node) { + if (!dma_has_cap(cap, device->cap_mask) || + dma_has_cap(DMA_PRIVATE, device->cap_mask)) + continue; + list_for_each_entry(chan, &device->channels, device_node) { + if (!chan->client_count) + continue; + if (!min || chan->table_count < min->table_count) + min = chan; + + if (dma_chan_is_local(chan, cpu)) + if (!localmin || + chan->table_count < localmin->table_count) + localmin = chan; + } + } + + chan = localmin ? localmin : min; + + if (chan) + chan->table_count++; + + return chan; +} + +/** + * dma_channel_rebalance - redistribute the available channels + * + * Optimize for cpu isolation (each cpu gets a dedicated channel for an + * operation type) in the SMP case, and operation isolation (avoid + * multi-tasking channels) in the non-SMP case. Must be called under + * dma_list_mutex. + */ +static void dma_channel_rebalance(void) +{ + struct dma_chan *chan; + struct dma_device *device; + int cpu; + int cap; + + /* undo the last distribution */ + for_each_dma_cap_mask(cap, dma_cap_mask_all) + for_each_possible_cpu(cpu) + per_cpu_ptr(channel_table[cap], cpu)->chan = NULL; + + list_for_each_entry(device, &dma_device_list, global_node) { + if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) + continue; + list_for_each_entry(chan, &device->channels, device_node) + chan->table_count = 0; + } + + /* don't populate the channel_table if no clients are available */ + if (!dmaengine_ref_count) + return; + + /* redistribute available channels */ + for_each_dma_cap_mask(cap, dma_cap_mask_all) + for_each_online_cpu(cpu) { + chan = min_chan(cap, cpu); + per_cpu_ptr(channel_table[cap], cpu)->chan = chan; + } +} + +static struct dma_chan *private_candidate(const dma_cap_mask_t *mask, + struct dma_device *dev, + dma_filter_fn fn, void *fn_param) +{ + struct dma_chan *chan; + + if (!__dma_device_satisfies_mask(dev, mask)) { + pr_debug("%s: wrong capabilities\n", __func__); + return NULL; + } + /* devices with multiple channels need special handling as we need to + * ensure that all channels are either private or public. + */ + if (dev->chancnt > 1 && !dma_has_cap(DMA_PRIVATE, dev->cap_mask)) + list_for_each_entry(chan, &dev->channels, device_node) { + /* some channels are already publicly allocated */ + if (chan->client_count) + return NULL; + } + + list_for_each_entry(chan, &dev->channels, device_node) { + if (chan->client_count) { + pr_debug("%s: %s busy\n", + __func__, dma_chan_name(chan)); + continue; + } + if (fn && !fn(chan, fn_param)) { + pr_debug("%s: %s filter said false\n", + __func__, dma_chan_name(chan)); + continue; + } + return chan; + } + + return NULL; } /** - * dma_chans_notify_available - tell the clients that a channel is going away - * @chan: channel on its way out + * dma_request_slave_channel - try to get specific channel exclusively + * @chan: target channel */ -static void dma_clients_notify_removed(struct dma_chan *chan) +struct dma_chan *dma_get_slave_channel(struct dma_chan *chan) { - struct dma_client *client; - enum dma_state_client ack; + int err = -EBUSY; + /* lock against __dma_request_channel */ mutex_lock(&dma_list_mutex); - list_for_each_entry(client, &dma_client_list, global_node) { - ack = client->event_callback(client, chan, - DMA_RESOURCE_REMOVED); + if (chan->client_count == 0) { + err = dma_chan_get(chan); + if (err) + pr_debug("%s: failed to get %s: (%d)\n", + __func__, dma_chan_name(chan), err); + } else + chan = NULL; - /* client was holding resources for this channel so - * free it - */ - if (ack == DMA_ACK) - dma_chan_put(chan); + mutex_unlock(&dma_list_mutex); + + + return chan; +} +EXPORT_SYMBOL_GPL(dma_get_slave_channel); + +struct dma_chan *dma_get_any_slave_channel(struct dma_device *device) +{ + dma_cap_mask_t mask; + struct dma_chan *chan; + int err; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + /* lock against __dma_request_channel */ + mutex_lock(&dma_list_mutex); + + chan = private_candidate(&mask, device, NULL, NULL); + if (chan) { + err = dma_chan_get(chan); + if (err) { + pr_debug("%s: failed to get %s: (%d)\n", + __func__, dma_chan_name(chan), err); + chan = NULL; + } } mutex_unlock(&dma_list_mutex); + + return chan; } +EXPORT_SYMBOL_GPL(dma_get_any_slave_channel); /** - * dma_async_client_register - register a &dma_client - * @client: ptr to a client structure with valid 'event_callback' and 'cap_mask' + * __dma_request_channel - try to allocate an exclusive channel + * @mask: capabilities that the channel must satisfy + * @fn: optional callback to disposition available channels + * @fn_param: opaque parameter to pass to dma_filter_fn + * + * Returns pointer to appropriate DMA channel on success or NULL. */ -void dma_async_client_register(struct dma_client *client) +struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask, + dma_filter_fn fn, void *fn_param) { + struct dma_device *device, *_d; + struct dma_chan *chan = NULL; + int err; + + /* Find a channel */ mutex_lock(&dma_list_mutex); - list_add_tail(&client->global_node, &dma_client_list); + list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { + chan = private_candidate(mask, device, fn, fn_param); + if (chan) { + /* Found a suitable channel, try to grab, prep, and + * return it. We first set DMA_PRIVATE to disable + * balance_ref_count as this channel will not be + * published in the general-purpose allocator + */ + dma_cap_set(DMA_PRIVATE, device->cap_mask); + device->privatecnt++; + err = dma_chan_get(chan); + + if (err == -ENODEV) { + pr_debug("%s: %s module removed\n", + __func__, dma_chan_name(chan)); + list_del_rcu(&device->global_node); + } else if (err) + pr_debug("%s: failed to get %s: (%d)\n", + __func__, dma_chan_name(chan), err); + else + break; + if (--device->privatecnt == 0) + dma_cap_clear(DMA_PRIVATE, device->cap_mask); + chan = NULL; + } + } mutex_unlock(&dma_list_mutex); + + pr_debug("%s: %s (%s)\n", + __func__, + chan ? "success" : "fail", + chan ? dma_chan_name(chan) : NULL); + + return chan; } -EXPORT_SYMBOL(dma_async_client_register); +EXPORT_SYMBOL_GPL(__dma_request_channel); /** - * dma_async_client_unregister - unregister a client and free the &dma_client - * @client: &dma_client to free + * dma_request_slave_channel - try to allocate an exclusive slave channel + * @dev: pointer to client device structure + * @name: slave channel name * - * Force frees any allocated DMA channels, frees the &dma_client memory + * Returns pointer to appropriate DMA channel on success or an error pointer. */ -void dma_async_client_unregister(struct dma_client *client) +struct dma_chan *dma_request_slave_channel_reason(struct device *dev, + const char *name) { - struct dma_device *device; - struct dma_chan *chan; - enum dma_state_client ack; + /* If device-tree is present get slave info from here */ + if (dev->of_node) + return of_dma_request_slave_channel(dev->of_node, name); - if (!client) - return; + /* If device was enumerated by ACPI get slave info from here */ + if (ACPI_HANDLE(dev)) + return acpi_dma_request_slave_chan_by_name(dev, name); + return ERR_PTR(-ENODEV); +} +EXPORT_SYMBOL_GPL(dma_request_slave_channel_reason); + +/** + * dma_request_slave_channel - try to allocate an exclusive slave channel + * @dev: pointer to client device structure + * @name: slave channel name + * + * Returns pointer to appropriate DMA channel on success or NULL. + */ +struct dma_chan *dma_request_slave_channel(struct device *dev, + const char *name) +{ + struct dma_chan *ch = dma_request_slave_channel_reason(dev, name); + if (IS_ERR(ch)) + return NULL; + return ch; +} +EXPORT_SYMBOL_GPL(dma_request_slave_channel); + +void dma_release_channel(struct dma_chan *chan) +{ mutex_lock(&dma_list_mutex); - /* free all channels the client is holding */ - list_for_each_entry(device, &dma_device_list, global_node) - list_for_each_entry(chan, &device->channels, device_node) { - ack = client->event_callback(client, chan, - DMA_RESOURCE_REMOVED); + WARN_ONCE(chan->client_count != 1, + "chan reference count %d != 1\n", chan->client_count); + dma_chan_put(chan); + /* drop PRIVATE cap enabled by __dma_request_channel() */ + if (--chan->device->privatecnt == 0) + dma_cap_clear(DMA_PRIVATE, chan->device->cap_mask); + mutex_unlock(&dma_list_mutex); +} +EXPORT_SYMBOL_GPL(dma_release_channel); - if (ack == DMA_ACK) - dma_chan_put(chan); +/** + * dmaengine_get - register interest in dma_channels + */ +void dmaengine_get(void) +{ + struct dma_device *device, *_d; + struct dma_chan *chan; + int err; + + mutex_lock(&dma_list_mutex); + dmaengine_ref_count++; + + /* try to grab channels */ + list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { + if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) + continue; + list_for_each_entry(chan, &device->channels, device_node) { + err = dma_chan_get(chan); + if (err == -ENODEV) { + /* module removed before we could use it */ + list_del_rcu(&device->global_node); + break; + } else if (err) + pr_debug("%s: failed to get %s: (%d)\n", + __func__, dma_chan_name(chan), err); } + } - list_del(&client->global_node); + /* if this is the first reference and there were channels + * waiting we need to rebalance to get those channels + * incorporated into the channel table + */ + if (dmaengine_ref_count == 1) + dma_channel_rebalance(); mutex_unlock(&dma_list_mutex); } -EXPORT_SYMBOL(dma_async_client_unregister); +EXPORT_SYMBOL(dmaengine_get); /** - * dma_async_client_chan_request - send all available channels to the - * client that satisfy the capability mask - * @client - requester + * dmaengine_put - let dma drivers be removed when ref_count == 0 */ -void dma_async_client_chan_request(struct dma_client *client) +void dmaengine_put(void) +{ + struct dma_device *device; + struct dma_chan *chan; + + mutex_lock(&dma_list_mutex); + dmaengine_ref_count--; + BUG_ON(dmaengine_ref_count < 0); + /* drop channel references */ + list_for_each_entry(device, &dma_device_list, global_node) { + if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) + continue; + list_for_each_entry(chan, &device->channels, device_node) + dma_chan_put(chan); + } + mutex_unlock(&dma_list_mutex); +} +EXPORT_SYMBOL(dmaengine_put); + +static bool device_has_all_tx_types(struct dma_device *device) { + /* A device that satisfies this test has channels that will never cause + * an async_tx channel switch event as all possible operation types can + * be handled. + */ + #ifdef CONFIG_ASYNC_TX_DMA + if (!dma_has_cap(DMA_INTERRUPT, device->cap_mask)) + return false; + #endif + + #if defined(CONFIG_ASYNC_MEMCPY) || defined(CONFIG_ASYNC_MEMCPY_MODULE) + if (!dma_has_cap(DMA_MEMCPY, device->cap_mask)) + return false; + #endif + + #if defined(CONFIG_ASYNC_XOR) || defined(CONFIG_ASYNC_XOR_MODULE) + if (!dma_has_cap(DMA_XOR, device->cap_mask)) + return false; + + #ifndef CONFIG_ASYNC_TX_DISABLE_XOR_VAL_DMA + if (!dma_has_cap(DMA_XOR_VAL, device->cap_mask)) + return false; + #endif + #endif + + #if defined(CONFIG_ASYNC_PQ) || defined(CONFIG_ASYNC_PQ_MODULE) + if (!dma_has_cap(DMA_PQ, device->cap_mask)) + return false; + + #ifndef CONFIG_ASYNC_TX_DISABLE_PQ_VAL_DMA + if (!dma_has_cap(DMA_PQ_VAL, device->cap_mask)) + return false; + #endif + #endif + + return true; +} + +static int get_dma_id(struct dma_device *device) +{ + int rc; + mutex_lock(&dma_list_mutex); - dma_client_chan_alloc(client); + + rc = idr_alloc(&dma_idr, NULL, 0, 0, GFP_KERNEL); + if (rc >= 0) + device->dev_id = rc; + mutex_unlock(&dma_list_mutex); + return rc < 0 ? rc : 0; } -EXPORT_SYMBOL(dma_async_client_chan_request); /** * dma_async_device_register - registers DMA devices found @@ -341,9 +788,9 @@ EXPORT_SYMBOL(dma_async_client_chan_request); */ int dma_async_device_register(struct dma_device *device) { - static int id; int chancnt = 0, rc; struct dma_chan* chan; + atomic_t *idr_ref; if (!device) return -ENODEV; @@ -353,67 +800,123 @@ int dma_async_device_register(struct dma_device *device) !device->device_prep_dma_memcpy); BUG_ON(dma_has_cap(DMA_XOR, device->cap_mask) && !device->device_prep_dma_xor); - BUG_ON(dma_has_cap(DMA_ZERO_SUM, device->cap_mask) && - !device->device_prep_dma_zero_sum); - BUG_ON(dma_has_cap(DMA_MEMSET, device->cap_mask) && - !device->device_prep_dma_memset); + BUG_ON(dma_has_cap(DMA_XOR_VAL, device->cap_mask) && + !device->device_prep_dma_xor_val); + BUG_ON(dma_has_cap(DMA_PQ, device->cap_mask) && + !device->device_prep_dma_pq); + BUG_ON(dma_has_cap(DMA_PQ_VAL, device->cap_mask) && + !device->device_prep_dma_pq_val); BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) && !device->device_prep_dma_interrupt); + BUG_ON(dma_has_cap(DMA_SG, device->cap_mask) && + !device->device_prep_dma_sg); + BUG_ON(dma_has_cap(DMA_CYCLIC, device->cap_mask) && + !device->device_prep_dma_cyclic); + BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) && + !device->device_control); + BUG_ON(dma_has_cap(DMA_INTERLEAVE, device->cap_mask) && + !device->device_prep_interleaved_dma); 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_tx_status); BUG_ON(!device->device_issue_pending); BUG_ON(!device->dev); - init_completion(&device->done); - kref_init(&device->refcount); - device->dev_id = id++; + /* note: this only matters in the + * CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH=n case + */ + if (device_has_all_tx_types(device)) + dma_cap_set(DMA_ASYNC_TX, device->cap_mask); + + idr_ref = kmalloc(sizeof(*idr_ref), GFP_KERNEL); + if (!idr_ref) + return -ENOMEM; + rc = get_dma_id(device); + if (rc != 0) { + kfree(idr_ref); + return rc; + } + + atomic_set(idr_ref, 0); /* represent channels in sysfs. Probably want devs too */ list_for_each_entry(chan, &device->channels, device_node) { + rc = -ENOMEM; chan->local = alloc_percpu(typeof(*chan->local)); if (chan->local == NULL) - continue; + goto err_out; + chan->dev = kzalloc(sizeof(*chan->dev), GFP_KERNEL); + if (chan->dev == NULL) { + free_percpu(chan->local); + chan->local = NULL; + goto err_out; + } 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); - - rc = device_register(&chan->dev); + chan->dev->device.class = &dma_devclass; + chan->dev->device.parent = device->dev; + chan->dev->chan = chan; + chan->dev->idr_ref = idr_ref; + chan->dev->dev_id = device->dev_id; + atomic_inc(idr_ref); + dev_set_name(&chan->dev->device, "dma%dchan%d", + device->dev_id, chan->chan_id); + + rc = device_register(&chan->dev->device); if (rc) { - chancnt--; free_percpu(chan->local); chan->local = NULL; + kfree(chan->dev); + atomic_dec(idr_ref); goto err_out; } - - /* One for the channel, one of the class device */ - kref_get(&device->refcount); - kref_get(&device->refcount); - kref_init(&chan->refcount); - chan->slow_ref = 0; - INIT_RCU_HEAD(&chan->rcu); + chan->client_count = 0; } + device->chancnt = chancnt; mutex_lock(&dma_list_mutex); - list_add_tail(&device->global_node, &dma_device_list); + /* take references on public channels */ + if (dmaengine_ref_count && !dma_has_cap(DMA_PRIVATE, device->cap_mask)) + list_for_each_entry(chan, &device->channels, device_node) { + /* if clients are already waiting for channels we need + * to take references on their behalf + */ + if (dma_chan_get(chan) == -ENODEV) { + /* note we can only get here for the first + * channel as the remaining channels are + * guaranteed to get a reference + */ + rc = -ENODEV; + mutex_unlock(&dma_list_mutex); + goto err_out; + } + } + list_add_tail_rcu(&device->global_node, &dma_device_list); + if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) + device->privatecnt++; /* Always private */ + dma_channel_rebalance(); mutex_unlock(&dma_list_mutex); - dma_clients_notify_available(); - return 0; err_out: + /* if we never registered a channel just release the idr */ + if (atomic_read(idr_ref) == 0) { + mutex_lock(&dma_list_mutex); + idr_remove(&dma_idr, device->dev_id); + mutex_unlock(&dma_list_mutex); + kfree(idr_ref); + return rc; + } + list_for_each_entry(chan, &device->channels, device_node) { if (chan->local == NULL) continue; - kref_put(&device->refcount, dma_async_device_cleanup); - device_unregister(&chan->dev); - chancnt--; + mutex_lock(&dma_list_mutex); + chan->dev->chan = NULL; + mutex_unlock(&dma_list_mutex); + device_unregister(&chan->dev->device); free_percpu(chan->local); } return rc; @@ -421,130 +924,162 @@ err_out: EXPORT_SYMBOL(dma_async_device_register); /** - * dma_async_device_cleanup - function called when all references are released - * @kref: kernel reference object - */ -static void dma_async_device_cleanup(struct kref *kref) -{ - struct dma_device *device; - - device = container_of(kref, struct dma_device, refcount); - complete(&device->done); -} - -/** - * dma_async_device_unregister - unregisters DMA devices + * dma_async_device_unregister - unregister a DMA device * @device: &dma_device + * + * This routine is called by dma driver exit routines, dmaengine holds module + * references to prevent it being called while channels are in use. */ void dma_async_device_unregister(struct dma_device *device) { struct dma_chan *chan; mutex_lock(&dma_list_mutex); - list_del(&device->global_node); + list_del_rcu(&device->global_node); + dma_channel_rebalance(); mutex_unlock(&dma_list_mutex); list_for_each_entry(chan, &device->channels, device_node) { - dma_clients_notify_removed(chan); - device_unregister(&chan->dev); - dma_chan_release(chan); + WARN_ONCE(chan->client_count, + "%s called while %d clients hold a reference\n", + __func__, chan->client_count); + mutex_lock(&dma_list_mutex); + chan->dev->chan = NULL; + mutex_unlock(&dma_list_mutex); + device_unregister(&chan->dev->device); + free_percpu(chan->local); } - - kref_put(&device->refcount, dma_async_device_cleanup); - wait_for_completion(&device->done); } EXPORT_SYMBOL(dma_async_device_unregister); -/** - * dma_async_memcpy_buf_to_buf - offloaded copy between virtual addresses - * @chan: DMA channel to offload copy to - * @dest: destination address (virtual) - * @src: source address (virtual) - * @len: length - * - * Both @dest and @src must be mappable to a bus address according to the - * DMA mapping API rules for streaming mappings. - * Both @dest and @src must stay memory resident (kernel memory or locked - * user space pages). - */ -dma_cookie_t -dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest, - void *src, size_t len) -{ - struct dma_device *dev = chan->device; - struct dma_async_tx_descriptor *tx; - dma_addr_t dma_dest, dma_src; - dma_cookie_t cookie; - int cpu; +struct dmaengine_unmap_pool { + struct kmem_cache *cache; + const char *name; + mempool_t *pool; + size_t size; +}; - 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); +#define __UNMAP_POOL(x) { .size = x, .name = "dmaengine-unmap-" __stringify(x) } +static struct dmaengine_unmap_pool unmap_pool[] = { + __UNMAP_POOL(2), + #if IS_ENABLED(CONFIG_DMA_ENGINE_RAID) + __UNMAP_POOL(16), + __UNMAP_POOL(128), + __UNMAP_POOL(256), + #endif +}; - if (!tx) { - dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE); - dma_unmap_single(dev->dev, dma_dest, len, DMA_FROM_DEVICE); - return -ENOMEM; +static struct dmaengine_unmap_pool *__get_unmap_pool(int nr) +{ + int order = get_count_order(nr); + + switch (order) { + case 0 ... 1: + return &unmap_pool[0]; + case 2 ... 4: + return &unmap_pool[1]; + case 5 ... 7: + return &unmap_pool[2]; + case 8: + return &unmap_pool[3]; + default: + BUG(); + return NULL; } +} - tx->ack = 1; - tx->callback = NULL; - cookie = tx->tx_submit(tx); +static void dmaengine_unmap(struct kref *kref) +{ + struct dmaengine_unmap_data *unmap = container_of(kref, typeof(*unmap), kref); + struct device *dev = unmap->dev; + int cnt, i; + + cnt = unmap->to_cnt; + for (i = 0; i < cnt; i++) + dma_unmap_page(dev, unmap->addr[i], unmap->len, + DMA_TO_DEVICE); + cnt += unmap->from_cnt; + for (; i < cnt; i++) + dma_unmap_page(dev, unmap->addr[i], unmap->len, + DMA_FROM_DEVICE); + cnt += unmap->bidi_cnt; + for (; i < cnt; i++) { + if (unmap->addr[i] == 0) + continue; + dma_unmap_page(dev, unmap->addr[i], unmap->len, + DMA_BIDIRECTIONAL); + } + cnt = unmap->map_cnt; + mempool_free(unmap, __get_unmap_pool(cnt)->pool); +} - cpu = get_cpu(); - per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; - per_cpu_ptr(chan->local, cpu)->memcpy_count++; - put_cpu(); +void dmaengine_unmap_put(struct dmaengine_unmap_data *unmap) +{ + if (unmap) + kref_put(&unmap->kref, dmaengine_unmap); +} +EXPORT_SYMBOL_GPL(dmaengine_unmap_put); - return cookie; +static void dmaengine_destroy_unmap_pool(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) { + struct dmaengine_unmap_pool *p = &unmap_pool[i]; + + if (p->pool) + mempool_destroy(p->pool); + p->pool = NULL; + if (p->cache) + kmem_cache_destroy(p->cache); + p->cache = NULL; + } } -EXPORT_SYMBOL(dma_async_memcpy_buf_to_buf); -/** - * dma_async_memcpy_buf_to_pg - offloaded copy from address to page - * @chan: DMA channel to offload copy to - * @page: destination page - * @offset: offset in page to copy to - * @kdata: source address (virtual) - * @len: length - * - * Both @page/@offset and @kdata must be mappable to a bus address according - * to the DMA mapping API rules for streaming mappings. - * Both @page/@offset and @kdata must stay memory resident (kernel memory or - * locked user space pages) - */ -dma_cookie_t -dma_async_memcpy_buf_to_pg(struct dma_chan *chan, struct page *page, - unsigned int offset, void *kdata, size_t len) +static int __init dmaengine_init_unmap_pool(void) { - struct dma_device *dev = chan->device; - struct dma_async_tx_descriptor *tx; - dma_addr_t dma_dest, dma_src; - dma_cookie_t cookie; - int cpu; + int i; - 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); + for (i = 0; i < ARRAY_SIZE(unmap_pool); i++) { + struct dmaengine_unmap_pool *p = &unmap_pool[i]; + size_t size; - if (!tx) { - dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE); - dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE); - return -ENOMEM; + size = sizeof(struct dmaengine_unmap_data) + + sizeof(dma_addr_t) * p->size; + + p->cache = kmem_cache_create(p->name, size, 0, + SLAB_HWCACHE_ALIGN, NULL); + if (!p->cache) + break; + p->pool = mempool_create_slab_pool(1, p->cache); + if (!p->pool) + break; } - tx->ack = 1; - tx->callback = NULL; - cookie = tx->tx_submit(tx); + if (i == ARRAY_SIZE(unmap_pool)) + return 0; - cpu = get_cpu(); - per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; - per_cpu_ptr(chan->local, cpu)->memcpy_count++; - put_cpu(); + dmaengine_destroy_unmap_pool(); + return -ENOMEM; +} - return cookie; +struct dmaengine_unmap_data * +dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags) +{ + struct dmaengine_unmap_data *unmap; + + unmap = mempool_alloc(__get_unmap_pool(nr)->pool, flags); + if (!unmap) + return NULL; + + memset(unmap, 0, sizeof(*unmap)); + kref_init(&unmap->kref); + unmap->dev = dev; + unmap->map_cnt = nr; + + return unmap; } -EXPORT_SYMBOL(dma_async_memcpy_buf_to_pg); +EXPORT_SYMBOL(dmaengine_get_unmap_data); /** * dma_async_memcpy_pg_to_pg - offloaded copy from page to page @@ -567,48 +1102,168 @@ dma_async_memcpy_pg_to_pg(struct dma_chan *chan, struct page *dest_pg, { struct dma_device *dev = chan->device; struct dma_async_tx_descriptor *tx; - dma_addr_t dma_dest, dma_src; + struct dmaengine_unmap_data *unmap; dma_cookie_t cookie; - int cpu; + unsigned long flags; - 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); + unmap = dmaengine_get_unmap_data(dev->dev, 2, GFP_NOWAIT); + if (!unmap) + return -ENOMEM; + + unmap->to_cnt = 1; + unmap->from_cnt = 1; + unmap->addr[0] = dma_map_page(dev->dev, src_pg, src_off, len, + DMA_TO_DEVICE); + unmap->addr[1] = dma_map_page(dev->dev, dest_pg, dest_off, len, + DMA_FROM_DEVICE); + unmap->len = len; + flags = DMA_CTRL_ACK; + tx = dev->device_prep_dma_memcpy(chan, unmap->addr[1], unmap->addr[0], + len, flags); if (!tx) { - dma_unmap_page(dev->dev, dma_src, len, DMA_TO_DEVICE); - dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE); + dmaengine_unmap_put(unmap); return -ENOMEM; } - tx->ack = 1; - tx->callback = NULL; + dma_set_unmap(tx, unmap); cookie = tx->tx_submit(tx); + dmaengine_unmap_put(unmap); - cpu = get_cpu(); - per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; - per_cpu_ptr(chan->local, cpu)->memcpy_count++; - put_cpu(); + preempt_disable(); + __this_cpu_add(chan->local->bytes_transferred, len); + __this_cpu_inc(chan->local->memcpy_count); + preempt_enable(); return cookie; } EXPORT_SYMBOL(dma_async_memcpy_pg_to_pg); +/** + * dma_async_memcpy_buf_to_buf - offloaded copy between virtual addresses + * @chan: DMA channel to offload copy to + * @dest: destination address (virtual) + * @src: source address (virtual) + * @len: length + * + * Both @dest and @src must be mappable to a bus address according to the + * DMA mapping API rules for streaming mappings. + * Both @dest and @src must stay memory resident (kernel memory or locked + * user space pages). + */ +dma_cookie_t +dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest, + void *src, size_t len) +{ + return dma_async_memcpy_pg_to_pg(chan, virt_to_page(dest), + (unsigned long) dest & ~PAGE_MASK, + virt_to_page(src), + (unsigned long) src & ~PAGE_MASK, len); +} +EXPORT_SYMBOL(dma_async_memcpy_buf_to_buf); + +/** + * dma_async_memcpy_buf_to_pg - offloaded copy from address to page + * @chan: DMA channel to offload copy to + * @page: destination page + * @offset: offset in page to copy to + * @kdata: source address (virtual) + * @len: length + * + * Both @page/@offset and @kdata must be mappable to a bus address according + * to the DMA mapping API rules for streaming mappings. + * Both @page/@offset and @kdata must stay memory resident (kernel memory or + * locked user space pages) + */ +dma_cookie_t +dma_async_memcpy_buf_to_pg(struct dma_chan *chan, struct page *page, + unsigned int offset, void *kdata, size_t len) +{ + return dma_async_memcpy_pg_to_pg(chan, page, offset, + virt_to_page(kdata), + (unsigned long) kdata & ~PAGE_MASK, len); +} +EXPORT_SYMBOL(dma_async_memcpy_buf_to_pg); + void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx, struct dma_chan *chan) { tx->chan = chan; + #ifdef CONFIG_ASYNC_TX_ENABLE_CHANNEL_SWITCH spin_lock_init(&tx->lock); - INIT_LIST_HEAD(&tx->depend_node); - INIT_LIST_HEAD(&tx->depend_list); + #endif } 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 + */ +enum dma_status +dma_wait_for_async_tx(struct dma_async_tx_descriptor *tx) +{ + unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000); + + if (!tx) + return DMA_COMPLETE; + + while (tx->cookie == -EBUSY) { + if (time_after_eq(jiffies, dma_sync_wait_timeout)) { + pr_err("%s timeout waiting for descriptor submission\n", + __func__); + return DMA_ERROR; + } + cpu_relax(); + } + return dma_sync_wait(tx->chan, tx->cookie); +} +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 = txd_next(tx); + struct dma_async_tx_descriptor *dep_next; + struct dma_chan *chan; + + if (!dep) + return; + + /* we'll submit tx->next now, so clear the link */ + txd_clear_next(tx); + 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) { + txd_lock(dep); + txd_clear_parent(dep); + dep_next = txd_next(dep); + if (dep_next && dep_next->chan == chan) + txd_clear_next(dep); /* ->next will be submitted */ + else + dep_next = NULL; /* submit current dep and terminate */ + txd_unlock(dep); + + 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); + int err = dmaengine_init_unmap_pool(); + + if (err) + return err; return class_register(&dma_devclass); } -subsys_initcall(dma_bus_init); +arch_initcall(dma_bus_init); + |