X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=drivers%2Fdma%2Fdmaengine.c;h=d5bc628d207cf29894a5d685e1d3df284b9788f6;hb=138f4c359d23d2ec38d18bd70dd9613ae515fe93;hp=7a0594f24a3f688ec16fcf79c04c8cb306c5f142;hpb=59b5ec21446b9239d706ab237fb261d525b75e81;p=safe%2Fjmp%2Flinux-2.6 diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index 7a0594f..d5bc628 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -31,32 +31,18 @@ * * 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 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 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 - * 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 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 + * See Documentation/dmaengine.txt for more details */ #include @@ -71,44 +57,84 @@ #include #include #include +#include static DEFINE_MUTEX(dma_list_mutex); static LIST_HEAD(dma_device_list); -static LIST_HEAD(dma_client_list); static long dmaengine_ref_count; +static struct idr dma_idr; /* --- sysfs implementation --- */ +/** + * 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 show_memcpy_count(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 ssize_t show_bytes_transferred(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 ssize_t show_in_use(struct device *dev, struct device_attribute *attr, char *buf) { - struct dma_chan *chan = to_dma_chan(dev); + struct dma_chan *chan; + int err; - return sprintf(buf, "%d\n", chan->client_count); + 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 err; } static struct device_attribute dma_attrs[] = { @@ -118,18 +144,24 @@ static struct device_attribute dma_attrs[] = { __ATTR_NULL }; -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_release = chan_dev_release, }; /* --- client and device registration --- */ @@ -189,7 +221,7 @@ static int dma_chan_get(struct dma_chan *chan) /* allocate upon first client reference */ if (chan->client_count == 1 && err == 0) { - int desc_cnt = chan->device->device_alloc_chan_resources(chan, NULL); + int desc_cnt = chan->device->device_alloc_chan_resources(chan); if (desc_cnt < 0) { err = desc_cnt; @@ -218,44 +250,6 @@ static void dma_chan_put(struct dma_chan *chan) chan->device->device_free_chan_resources(chan); } -/** - * dma_client_chan_alloc - try to allocate channels to a client - * @client: &dma_client - * - * Called with dma_list_mutex held. - */ -static void dma_client_chan_alloc(struct dma_client *client) -{ - struct dma_device *device; - struct dma_chan *chan; - enum dma_state_client ack; - - /* Find a channel */ - list_for_each_entry(device, &dma_device_list, global_node) { - if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) - continue; - /* Does the client require a specific DMA controller? */ - if (client->slave && client->slave->dma_dev - && client->slave->dma_dev != device->dev) - continue; - if (!dma_device_satisfies_mask(device, client->cap_mask)) - continue; - - list_for_each_entry(chan, &device->channels, device_node) { - if (!chan->client_count) - continue; - ack = client->event_callback(client, chan, - DMA_RESOURCE_AVAILABLE); - - /* we are done once this client rejects - * an available resource - */ - if (ack == DMA_NAK) - return; - } - } -} - enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie) { enum dma_status status; @@ -275,29 +269,6 @@ enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie) EXPORT_SYMBOL(dma_sync_wait); /** - * dma_chan_cleanup - release a DMA channel's resources - * @kref: kernel reference structure that contains the DMA channel device - */ -void dma_chan_cleanup(struct kref *kref) -{ - struct dma_chan *chan = container_of(kref, struct dma_chan, refcount); - kref_put(&chan->device->refcount, dma_async_device_cleanup); -} -EXPORT_SYMBOL(dma_chan_cleanup); - -static void dma_chan_free_rcu(struct rcu_head *rcu) -{ - struct dma_chan *chan = container_of(rcu, struct dma_chan, rcu); - - kref_put(&chan->refcount, dma_chan_cleanup); -} - -static void dma_chan_release(struct dma_chan *chan) -{ - call_rcu(&chan->rcu, dma_chan_free_rcu); -} - -/** * dma_cap_mask_all - enable iteration over all operation types */ static dma_cap_mask_t dma_cap_mask_all; @@ -347,7 +318,7 @@ static int __init dma_channel_table_init(void) return err; } -subsys_initcall(dma_channel_table_init); +arch_initcall(dma_channel_table_init); /** * dma_find_channel - find a channel to carry out the operation @@ -358,9 +329,6 @@ struct dma_chan *dma_find_channel(enum dma_transaction_type tx_type) struct dma_chan *chan; int cpu; - WARN_ONCE(dmaengine_ref_count == 0, - "client called %s without a reference", __func__); - cpu = get_cpu(); chan = per_cpu_ptr(channel_table[tx_type], cpu)->chan; put_cpu(); @@ -377,9 +345,6 @@ void dma_issue_pending_all(void) struct dma_device *device; struct dma_chan *chan; - WARN_ONCE(dmaengine_ref_count == 0, - "client called %s without a reference", __func__); - rcu_read_lock(); list_for_each_entry_rcu(device, &dma_device_list, global_node) { if (dma_has_cap(DMA_PRIVATE, device->cap_mask)) @@ -483,10 +448,10 @@ static void dma_channel_rebalance(void) } } -static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_device *dev) +static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_device *dev, + dma_filter_fn fn, void *fn_param) { struct dma_chan *chan; - struct dma_chan *ret = NULL; if (!__dma_device_satisfies_mask(dev, mask)) { pr_debug("%s: wrong capabilities\n", __func__); @@ -505,14 +470,18 @@ static struct dma_chan *private_candidate(dma_cap_mask_t *mask, struct dma_devic list_for_each_entry(chan, &dev->channels, device_node) { if (chan->client_count) { pr_debug("%s: %s busy\n", - __func__, dev_name(&chan->dev)); + __func__, dma_chan_name(chan)); continue; } - ret = chan; - break; + if (fn && !fn(chan, fn_param)) { + pr_debug("%s: %s filter said false\n", + __func__, dma_chan_name(chan)); + continue; + } + return chan; } - return ret; + return NULL; } /** @@ -525,54 +494,41 @@ struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, v { struct dma_device *device, *_d; struct dma_chan *chan = NULL; - enum dma_state_client ack; int err; /* Find a channel */ mutex_lock(&dma_list_mutex); list_for_each_entry_safe(device, _d, &dma_device_list, global_node) { - chan = private_candidate(mask, device); - if (!chan) - continue; - - if (fn) - ack = fn(chan, fn_param); - else - ack = DMA_ACK; - - if (ack == DMA_ACK) { + 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__, - dev_name(&chan->dev)); + dma_chan_name(chan)); list_del_rcu(&device->global_node); } else if (err) pr_err("dmaengine: failed to get %s: (%d)\n", - dev_name(&chan->dev), err); + dma_chan_name(chan), err); else break; - } else if (ack == DMA_DUP) { - pr_debug("%s: %s filter said DMA_DUP\n", - __func__, dev_name(&chan->dev)); - } else if (ack == DMA_NAK) { - pr_debug("%s: %s filter said DMA_NAK\n", - __func__, dev_name(&chan->dev)); - break; - } else - WARN_ONCE(1, "filter_fn: unknown response?\n"); - chan = NULL; + if (--device->privatecnt == 0) + dma_cap_clear(DMA_PRIVATE, device->cap_mask); + chan->private = NULL; + chan = NULL; + } } mutex_unlock(&dma_list_mutex); pr_debug("%s: %s (%s)\n", __func__, chan ? "success" : "fail", - chan ? dev_name(&chan->dev) : NULL); + chan ? dma_chan_name(chan) : NULL); return chan; } @@ -584,39 +540,23 @@ void dma_release_channel(struct dma_chan *chan) 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); + chan->private = NULL; mutex_unlock(&dma_list_mutex); } EXPORT_SYMBOL_GPL(dma_release_channel); /** - * dma_chans_notify_available - broadcast available channels to the clients - */ -static void dma_clients_notify_available(void) -{ - struct dma_client *client; - - mutex_lock(&dma_list_mutex); - - list_for_each_entry(client, &dma_client_list, global_node) - dma_client_chan_alloc(client); - - mutex_unlock(&dma_list_mutex); -} - -/** - * dma_async_client_register - register a &dma_client - * @client: ptr to a client structure with valid 'event_callback' and 'cap_mask' + * dmaengine_get - register interest in dma_channels */ -void dma_async_client_register(struct dma_client *client) +void dmaengine_get(void) { struct dma_device *device, *_d; struct dma_chan *chan; int err; - /* validate client data */ - BUG_ON(dma_has_cap(DMA_SLAVE, client->cap_mask) && - !client->slave); - mutex_lock(&dma_list_mutex); dmaengine_ref_count++; @@ -632,7 +572,7 @@ void dma_async_client_register(struct dma_client *client) break; } else if (err) pr_err("dmaengine: failed to get %s: (%d)\n", - dev_name(&chan->dev), err); + dma_chan_name(chan), err); } } @@ -642,25 +582,18 @@ void dma_async_client_register(struct dma_client *client) */ if (dmaengine_ref_count == 1) dma_channel_rebalance(); - list_add_tail(&client->global_node, &dma_client_list); mutex_unlock(&dma_list_mutex); } -EXPORT_SYMBOL(dma_async_client_register); +EXPORT_SYMBOL(dmaengine_get); /** - * dma_async_client_unregister - unregister a client and free the &dma_client - * @client: &dma_client to free - * - * Force frees any allocated DMA channels, frees the &dma_client memory + * dmaengine_put - let dma drivers be removed when ref_count == 0 */ -void dma_async_client_unregister(struct dma_client *client) +void dmaengine_put(void) { struct dma_device *device; struct dma_chan *chan; - if (!client) - return; - mutex_lock(&dma_list_mutex); dmaengine_ref_count--; BUG_ON(dmaengine_ref_count < 0); @@ -671,24 +604,61 @@ void dma_async_client_unregister(struct dma_client *client) list_for_each_entry(chan, &device->channels, device_node) dma_chan_put(chan); } - - list_del(&client->global_node); mutex_unlock(&dma_list_mutex); } -EXPORT_SYMBOL(dma_async_client_unregister); +EXPORT_SYMBOL(dmaengine_put); -/** - * dma_async_client_chan_request - send all available channels to the - * client that satisfy the capability mask - * @client - requester - */ -void dma_async_client_chan_request(struct dma_client *client) +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_MEMSET) || defined(CONFIG_ASYNC_MEMSET_MODULE) + if (!dma_has_cap(DMA_MEMSET, 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; + #endif + + #if defined(CONFIG_ASYNC_PQ) || defined(CONFIG_ASYNC_PQ_MODULE) + if (!dma_has_cap(DMA_PQ, device->cap_mask)) + return false; + #endif + + return true; +} + +static int get_dma_id(struct dma_device *device) +{ + int rc; + + idr_retry: + if (!idr_pre_get(&dma_idr, GFP_KERNEL)) + return -ENOMEM; mutex_lock(&dma_list_mutex); - dma_client_chan_alloc(client); + rc = idr_get_new(&dma_idr, NULL, &device->dev_id); mutex_unlock(&dma_list_mutex); + if (rc == -EAGAIN) + goto idr_retry; + else if (rc != 0) + return rc; + + return 0; } -EXPORT_SYMBOL(dma_async_client_chan_request); /** * dma_async_device_register - registers DMA devices found @@ -696,9 +666,9 @@ 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; @@ -708,8 +678,12 @@ 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_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_MEMSET, device->cap_mask) && !device->device_prep_dma_memset); BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) && @@ -725,40 +699,55 @@ int dma_async_device_register(struct dma_device *device) BUG_ON(!device->device_issue_pending); BUG_ON(!device->dev); - init_completion(&device->done); - kref_init(&device->refcount); + /* note: this only matters in the + * CONFIG_ASYNC_TX_DISABLE_CHANNEL_SWITCH=y case + */ + if (device_has_all_tx_types(device)) + dma_cap_set(DMA_ASYNC_TX, device->cap_mask); - mutex_lock(&dma_list_mutex); - device->dev_id = id++; - mutex_unlock(&dma_list_mutex); + 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 = device->dev; - dev_set_name(&chan->dev, "dma%dchan%d", + 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); + 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->client_count = 0; - chan->slow_ref = 0; - INIT_RCU_HEAD(&chan->rcu); } device->chancnt = chancnt; @@ -780,20 +769,30 @@ int dma_async_device_register(struct dma_device *device) } } 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; @@ -801,20 +800,11 @@ 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 - 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) { @@ -829,12 +819,11 @@ void dma_async_device_unregister(struct dma_device *device) WARN_ONCE(chan->client_count, "%s called while %d clients hold a reference\n", __func__, chan->client_count); - device_unregister(&chan->dev); - dma_chan_release(chan); + mutex_lock(&dma_list_mutex); + chan->dev->chan = NULL; + mutex_unlock(&dma_list_mutex); + device_unregister(&chan->dev->device); } - - kref_put(&device->refcount, dma_async_device_cleanup); - wait_for_completion(&device->done); } EXPORT_SYMBOL(dma_async_device_unregister); @@ -859,11 +848,14 @@ dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest, dma_addr_t dma_dest, dma_src; dma_cookie_t cookie; int cpu; + unsigned long flags; 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, - DMA_CTRL_ACK); + flags = DMA_CTRL_ACK | + DMA_COMPL_SRC_UNMAP_SINGLE | + DMA_COMPL_DEST_UNMAP_SINGLE; + tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags); if (!tx) { dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE); @@ -905,11 +897,12 @@ dma_async_memcpy_buf_to_pg(struct dma_chan *chan, struct page *page, dma_addr_t dma_dest, dma_src; dma_cookie_t cookie; int cpu; + unsigned long flags; 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, - DMA_CTRL_ACK); + flags = DMA_CTRL_ACK | DMA_COMPL_SRC_UNMAP_SINGLE; + tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags); if (!tx) { dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE); @@ -953,12 +946,13 @@ dma_async_memcpy_pg_to_pg(struct dma_chan *chan, struct page *dest_pg, dma_addr_t dma_dest, dma_src; 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, - DMA_CTRL_ACK); + flags = DMA_CTRL_ACK; + tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags); if (!tx) { dma_unmap_page(dev->dev, dma_src, len, DMA_TO_DEVICE); @@ -983,54 +977,30 @@ void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx, { tx->chan = chan; spin_lock_init(&tx->lock); + INIT_LIST_HEAD(&tx->tx_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; + unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000); 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; + 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); @@ -1047,6 +1017,8 @@ void dma_run_dependencies(struct dma_async_tx_descriptor *tx) if (!dep) return; + /* we'll submit tx->next now, so clear the link */ + tx->next = NULL; chan = dep->chan; /* keep submitting up until a channel switch is detected @@ -1072,9 +1044,10 @@ EXPORT_SYMBOL_GPL(dma_run_dependencies); static int __init dma_bus_init(void) { + idr_init(&dma_idr); mutex_init(&dma_list_mutex); return class_register(&dma_devclass); } -subsys_initcall(dma_bus_init); +arch_initcall(dma_bus_init);