diff options
| -rw-r--r-- | drivers/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/Makefile | 1 | ||||
| -rw-r--r-- | drivers/dma/Kconfig | 13 | ||||
| -rw-r--r-- | drivers/dma/Makefile | 1 | ||||
| -rw-r--r-- | drivers/dma/dmaengine.c | 408 | ||||
| -rw-r--r-- | include/linux/dmaengine.h | 337 |
6 files changed, 762 insertions, 0 deletions
diff --git a/drivers/Kconfig b/drivers/Kconfig index aeb5ab2391e..8b11cebe65d 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -72,4 +72,6 @@ source "drivers/edac/Kconfig" source "drivers/rtc/Kconfig" +source "drivers/dma/Kconfig" + endmenu diff --git a/drivers/Makefile b/drivers/Makefile index 447d8e68887..3c5170310bd 100644 --- a/drivers/Makefile +++ b/drivers/Makefile @@ -74,3 +74,4 @@ obj-$(CONFIG_SGI_SN) += sn/ obj-y += firmware/ obj-$(CONFIG_CRYPTO) += crypto/ obj-$(CONFIG_SUPERH) += sh/ +obj-$(CONFIG_DMA_ENGINE) += dma/ diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig new file mode 100644 index 00000000000..f9ac4bcf865 --- /dev/null +++ b/drivers/dma/Kconfig @@ -0,0 +1,13 @@ +# +# DMA engine configuration +# + +menu "DMA Engine support" + +config DMA_ENGINE + bool "Support for DMA engines" + ---help--- + DMA engines offload copy operations from the CPU to dedicated + hardware, allowing the copies to happen asynchronously. + +endmenu diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile new file mode 100644 index 00000000000..10b739138c9 --- /dev/null +++ b/drivers/dma/Makefile @@ -0,0 +1 @@ +obj-y += dmaengine.o diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c new file mode 100644 index 00000000000..473c47b6f09 --- /dev/null +++ b/drivers/dma/dmaengine.c @@ -0,0 +1,408 @@ +/* + * Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 59 + * Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * The full GNU General Public License is included in this distribution in the + * file called COPYING. + */ + +/* + * This code implements the DMA subsystem. It provides a HW-neutral interface + * for other kernel code to use asynchronous memory copy capabilities, + * if present, and allows different HW DMA drivers to register as providing + * this capability. + * + * Due to the fact we are accelerating what is already a relatively fast + * operation, the code goes to great lengths to avoid additional overhead, + * such as locking. + * + * 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. + * + * 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 has a channels list, it's only modified under the client->lock + * and in an RCU callback, so it's safe to read under rcu_read_lock(). + * + * Each device has a kref, which is initialized to 1 when the device is + * registered. A kref_put is done for each class_device registered. When the + * class_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, class_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 single reference is set when on an + * ADDED event, and removed with a REMOVE event. Net DMA client takes an + * extra reference per outstanding transaction. The relase function does a + * kref_put on the device. -ChrisL + */ + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/dmaengine.h> +#include <linux/hardirq.h> +#include <linux/spinlock.h> +#include <linux/percpu.h> +#include <linux/rcupdate.h> +#include <linux/mutex.h> + +static DEFINE_MUTEX(dma_list_mutex); +static LIST_HEAD(dma_device_list); +static LIST_HEAD(dma_client_list); + +/* --- sysfs implementation --- */ + +static ssize_t show_memcpy_count(struct class_device *cd, char *buf) +{ + struct dma_chan *chan = container_of(cd, struct dma_chan, class_dev); + unsigned long count = 0; + int i; + + for_each_cpu(i) + count += per_cpu_ptr(chan->local, i)->memcpy_count; + + return sprintf(buf, "%lu\n", count); +} + +static ssize_t show_bytes_transferred(struct class_device *cd, char *buf) +{ + struct dma_chan *chan = container_of(cd, struct dma_chan, class_dev); + unsigned long count = 0; + int i; + + for_each_cpu(i) + count += per_cpu_ptr(chan->local, i)->bytes_transferred; + + return sprintf(buf, "%lu\n", count); +} + +static ssize_t show_in_use(struct class_device *cd, char *buf) +{ + struct dma_chan *chan = container_of(cd, struct dma_chan, class_dev); + + return sprintf(buf, "%d\n", (chan->client ? 1 : 0)); +} + +static struct class_device_attribute dma_class_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 void dma_async_device_cleanup(struct kref *kref); + +static void dma_class_dev_release(struct class_device *cd) +{ + struct dma_chan *chan = container_of(cd, struct dma_chan, class_dev); + kref_put(&chan->device->refcount, dma_async_device_cleanup); +} + +static struct class dma_devclass = { + .name = "dma", + .class_dev_attrs = dma_class_attrs, + .release = dma_class_dev_release, +}; + +/* --- client and device registration --- */ + +/** + * dma_client_chan_alloc - try to allocate a channel to a client + * @client: &dma_client + * + * Called with dma_list_mutex held. + */ +static struct dma_chan *dma_client_chan_alloc(struct dma_client *client) +{ + struct dma_device *device; + struct dma_chan *chan; + unsigned long flags; + int desc; /* allocated descriptor count */ + + /* Find a channel, any DMA engine will do */ + list_for_each_entry(device, &dma_device_list, global_node) { + list_for_each_entry(chan, &device->channels, device_node) { + if (chan->client) + continue; + + desc = chan->device->device_alloc_chan_resources(chan); + if (desc >= 0) { + kref_get(&device->refcount); + kref_init(&chan->refcount); + chan->slow_ref = 0; + INIT_RCU_HEAD(&chan->rcu); + chan->client = client; + spin_lock_irqsave(&client->lock, flags); + list_add_tail_rcu(&chan->client_node, + &client->channels); + spin_unlock_irqrestore(&client->lock, flags); + return chan; + } + } + } + + return NULL; +} + +/** + * dma_client_chan_free - release a DMA channel + * @chan: &dma_chan + */ +void dma_chan_cleanup(struct kref *kref) +{ + struct dma_chan *chan = container_of(kref, struct dma_chan, refcount); + chan->device->device_free_chan_resources(chan); + chan->client = NULL; + kref_put(&chan->device->refcount, dma_async_device_cleanup); +} + +static void dma_chan_free_rcu(struct rcu_head *rcu) +{ + struct dma_chan *chan = container_of(rcu, struct dma_chan, rcu); + int bias = 0x7FFFFFFF; + int i; + for_each_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); +} + +static void dma_client_chan_free(struct dma_chan *chan) +{ + atomic_add(0x7FFFFFFF, &chan->refcount.refcount); + chan->slow_ref = 1; + call_rcu(&chan->rcu, dma_chan_free_rcu); +} + +/** + * dma_chans_rebalance - reallocate channels to clients + * + * When the number of DMA channel in the system changes, + * channels need to be rebalanced among clients + */ +static void dma_chans_rebalance(void) +{ + struct dma_client *client; + struct dma_chan *chan; + unsigned long flags; + + mutex_lock(&dma_list_mutex); + + list_for_each_entry(client, &dma_client_list, global_node) { + while (client->chans_desired > client->chan_count) { + chan = dma_client_chan_alloc(client); + if (!chan) + break; + client->chan_count++; + client->event_callback(client, + chan, + DMA_RESOURCE_ADDED); + } + while (client->chans_desired < client->chan_count) { + spin_lock_irqsave(&client->lock, flags); + chan = list_entry(client->channels.next, + struct dma_chan, + client_node); + list_del_rcu(&chan->client_node); + spin_unlock_irqrestore(&client->lock, flags); + client->chan_count--; + client->event_callback(client, + chan, + DMA_RESOURCE_REMOVED); + dma_client_chan_free(chan); + } + } + + mutex_unlock(&dma_list_mutex); +} + +/** + * dma_async_client_register - allocate and register a &dma_client + * @event_callback: callback for notification of channel addition/removal + */ +struct dma_client *dma_async_client_register(dma_event_callback event_callback) +{ + struct dma_client *client; + + client = kzalloc(sizeof(*client), GFP_KERNEL); + if (!client) + return NULL; + + INIT_LIST_HEAD(&client->channels); + spin_lock_init(&client->lock); + client->chans_desired = 0; + client->chan_count = 0; + client->event_callback = event_callback; + + mutex_lock(&dma_list_mutex); + list_add_tail(&client->global_node, &dma_client_list); + mutex_unlock(&dma_list_mutex); + + return client; +} + +/** + * dma_async_client_unregister - unregister a client and free the &dma_client + * @client: + * + * Force frees any allocated DMA channels, frees the &dma_client memory + */ +void dma_async_client_unregister(struct dma_client *client) +{ + struct dma_chan *chan; + + if (!client) + return; + + rcu_read_lock(); + list_for_each_entry_rcu(chan, &client->channels, client_node) + dma_client_chan_free(chan); + rcu_read_unlock(); + + mutex_lock(&dma_list_mutex); + list_del(&client->global_node); + mutex_unlock(&dma_list_mutex); + + kfree(client); + dma_chans_rebalance(); +} + +/** + * dma_async_client_chan_request - request DMA channels + * @client: &dma_client + * @number: count of DMA channels requested + * + * Clients call dma_async_client_chan_request() to specify how many + * DMA channels they need, 0 to free all currently allocated. + * The resulting allocations/frees are indicated to the client via the + * event callback. + */ +void dma_async_client_chan_request(struct dma_client *client, + unsigned int number) +{ + client->chans_desired = number; + dma_chans_rebalance(); +} + +/** + * dma_async_device_register - + * @device: &dma_device + */ +int dma_async_device_register(struct dma_device *device) +{ + static int id; + int chancnt = 0; + struct dma_chan* chan; + + if (!device) + return -ENODEV; + + init_completion(&device->done); + kref_init(&device->refcount); + device->dev_id = id++; + + /* represent channels in sysfs. Probably want devs too */ + list_for_each_entry(chan, &device->channels, device_node) { + chan->local = alloc_percpu(typeof(*chan->local)); + if (chan->local == NULL) + continue; + + chan->chan_id = chancnt++; + chan->class_dev.class = &dma_devclass; + chan->class_dev.dev = NULL; + snprintf(chan->class_dev.class_id, BUS_ID_SIZE, "dma%dchan%d", + device->dev_id, chan->chan_id); + + kref_get(&device->refcount); + class_device_register(&chan->class_dev); + } + + mutex_lock(&dma_list_mutex); + list_add_tail(&device->global_node, &dma_device_list); + mutex_unlock(&dma_list_mutex); + + dma_chans_rebalance(); + + return 0; +} + +/** + * dma_async_device_unregister - + * @device: &dma_device + */ +static void dma_async_device_cleanup(struct kref *kref) +{ + struct dma_device *device; + + device = container_of(kref, struct dma_device, refcount); + complete(&device->done); +} + +void dma_async_device_unregister(struct dma_device* device) +{ + struct dma_chan *chan; + unsigned long flags; + + mutex_lock(&dma_list_mutex); + list_del(&device->global_node); + mutex_unlock(&dma_list_mutex); + + list_for_each_entry(chan, &device->channels, device_node) { + if (chan->client) { + spin_lock_irqsave(&chan->client->lock, flags); + list_del(&chan->client_node); + chan->client->chan_count--; + spin_unlock_irqrestore(&chan->client->lock, flags); + chan->client->event_callback(chan->client, + chan, + DMA_RESOURCE_REMOVED); + dma_client_chan_free(chan); + } + class_device_unregister(&chan->class_dev); + } + dma_chans_rebalance(); + + kref_put(&device->refcount, dma_async_device_cleanup); + wait_for_completion(&device->done); +} + +static int __init dma_bus_init(void) +{ + mutex_init(&dma_list_mutex); + return class_register(&dma_devclass); +} + +subsys_initcall(dma_bus_init); + +EXPORT_SYMBOL(dma_async_client_register); +EXPORT_SYMBOL(dma_async_client_unregister); +EXPORT_SYMBOL(dma_async_client_chan_request); +EXPORT_SYMBOL(dma_async_memcpy_buf_to_buf); +EXPORT_SYMBOL(dma_async_memcpy_buf_to_pg); +EXPORT_SYMBOL(dma_async_memcpy_pg_to_pg); +EXPORT_SYMBOL(dma_async_memcpy_complete); +EXPORT_SYMBOL(dma_async_memcpy_issue_pending); +EXPORT_SYMBOL(dma_async_device_register); +EXPORT_SYMBOL(dma_async_device_unregister); +EXPORT_SYMBOL(dma_chan_cleanup); diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h new file mode 100644 index 00000000000..30781546ac9 --- /dev/null +++ b/include/linux/dmaengine.h @@ -0,0 +1,337 @@ +/* + * Copyright(c) 2004 - 2006 Intel Corporation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the Free + * Software Foundation; either version 2 of the License, or (at your option) + * any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 59 + * Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * + * The full GNU General Public License is included in this distribution in the + * file called COPYING. + */ +#ifndef DMAENGINE_H +#define DMAENGINE_H +#include <linux/config.h> +#ifdef CONFIG_DMA_ENGINE + +#include <linux/device.h> +#include <linux/uio.h> +#include <linux/kref.h> +#include <linux/completion.h> +#include <linux/rcupdate.h> + +/** + * enum dma_event - resource PNP/power managment events + * @DMA_RESOURCE_SUSPEND: DMA device going into low power state + * @DMA_RESOURCE_RESUME: DMA device returning to full power + * @DMA_RESOURCE_ADDED: DMA device added to the system + * @DMA_RESOURCE_REMOVED: DMA device removed from the system + */ +enum dma_event { + DMA_RESOURCE_SUSPEND, + DMA_RESOURCE_RESUME, + DMA_RESOURCE_ADDED, + DMA_RESOURCE_REMOVED, +}; + +/** + * typedef dma_cookie_t + * + * if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code + */ +typedef s32 dma_cookie_t; + +#define dma_submit_error(cookie) ((cookie) < 0 ? 1 : 0) + +/** + * enum dma_status - DMA transaction status + * @DMA_SUCCESS: transaction completed successfully + * @DMA_IN_PROGRESS: transaction not yet processed + * @DMA_ERROR: transaction failed + */ +enum dma_status { + DMA_SUCCESS, + DMA_IN_PROGRESS, + DMA_ERROR, +}; + +/** + * struct dma_chan_percpu - the per-CPU part of struct dma_chan + * @refcount: local_t used for open-coded "bigref" counting + * @memcpy_count: transaction counter + * @bytes_transferred: byte counter + */ + +struct dma_chan_percpu { + local_t refcount; + /* stats */ + unsigned long memcpy_count; + unsigned long bytes_transferred; +}; + +/** + * struct dma_chan - devices supply DMA channels, clients use them + * @client: ptr to the client user of this chan, will be NULL when unused + * @device: ptr to the dma device who supplies this channel, always !NULL + * @cookie: last cookie value returned to client + * @chan_id: + * @class_dev: + * @refcount: kref, used in "bigref" slow-mode + * @slow_ref: + * @rcu: + * @client_node: used to add this to the client chan list + * @device_node: used to add this to the device chan list + * @local: per-cpu pointer to a struct dma_chan_percpu + */ +struct dma_chan { + struct dma_client *client; + struct dma_device *device; + dma_cookie_t cookie; + + /* sysfs */ + int chan_id; + struct class_device class_dev; + + struct kref refcount; + int slow_ref; + struct rcu_head rcu; + + struct list_head client_node; + struct list_head device_node; + struct dma_chan_percpu *local; +}; + +void dma_chan_cleanup(struct kref *kref); + +static inline void dma_chan_get(struct dma_chan *chan) +{ + if (unlikely(chan->slow_ref)) + kref_get(&chan->refcount); + else { + local_inc(&(per_cpu_ptr(chan->local, get_cpu())->refcount)); + put_cpu(); + } +} + +static inline void dma_chan_put(struct dma_chan *chan) +{ + if (unlikely(chan->slow_ref)) + kref_put(&chan->refcount, dma_chan_cleanup); + else { + local_dec(&(per_cpu_ptr(chan->local, get_cpu())->refcount)); + put_cpu(); + } +} + +/* + * typedef dma_event_callback - function pointer to a DMA event callback + */ +typedef void (*dma_event_callback) (struct dma_client *client, + struct dma_chan *chan, enum dma_event event); + +/** + * struct dma_client - info on the entity making use of DMA services + * @event_callback: func ptr to call when something happens + * @chan_count: number of chans allocated + * @chans_desired: number of chans requested. Can be +/- chan_count + * @lock: protects access to the channels list + * @channels: the list of DMA channels allocated + * @global_node: list_head for global dma_client_list + */ +struct dma_client { + dma_event_callback event_callback; + unsigned int chan_count; + unsigned int chans_desired; + + spinlock_t lock; + struct list_head channels; + struct list_head global_node; +}; + +/** + * struct dma_device - info on the entity supplying DMA services + * @chancnt: how many DMA channels are supported + * @channels: the list of struct dma_chan + * @global_node: list_head for global dma_device_list + * @refcount: + * @done: + * @dev_id: + * Other func ptrs: used to make use of this device's capabilities + */ +struct dma_device { + + unsigned int chancnt; + struct list_head channels; + struct list_head global_node; + + struct kref refcount; + struct completion done; + + int dev_id; + + int (*device_alloc_chan_resources)(struct dma_chan *chan); + void (*device_free_chan_resources)(struct dma_chan *chan); + dma_cookie_t (*device_memcpy_buf_to_buf)(struct dma_chan *chan, + void *dest, void *src, size_t len); + dma_cookie_t (*device_memcpy_buf_to_pg)(struct dma_chan *chan, + struct page *page, unsigned int offset, void *kdata, + size_t len); + dma_cookie_t (*device_memcpy_pg_to_pg)(struct dma_chan *chan, + struct page *dest_pg, unsigned int dest_off, + struct page *src_pg, unsigned int src_off, size_t len); + enum dma_status (*device_memcpy_complete)(struct dma_chan *chan, + dma_cookie_t cookie, dma_cookie_t *last, + dma_cookie_t *used); + void (*device_memcpy_issue_pending)(struct dma_chan *chan); +}; + +/* --- public DMA engine API --- */ + +struct dma_client *dma_async_client_register(dma_event_callback event_callback); +void dma_async_client_unregister(struct dma_client *client); +void dma_async_client_chan_request(struct dma_client *client, + unsigned int number); + +/** + * 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) + */ +static inline dma_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan, + void *dest, void *src, size_t len) +{ + int cpu = get_cpu(); + per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; + per_cpu_ptr(chan->local, cpu)->memcpy_count++; + put_cpu(); + + return chan->device->device_memcpy_buf_to_buf(chan, dest, src, len); +} + +/** + * dma_async_memcpy_buf_to_pg - offloaded copy + * @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) + */ +static inline dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan, + struct page *page, unsigned int offset, void *kdata, size_t len) +{ + int cpu = get_cpu(); + per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; + per_cpu_ptr(chan->local, cpu)->memcpy_count++; + put_cpu(); + + return chan->device->device_memcpy_buf_to_pg(chan, page, offset, + kdata, len); +} + +/** + * dma_async_memcpy_buf_to_pg - offloaded copy + * @chan: DMA channel to offload copy to + * @dest_page: destination page + * @dest_off: offset in page to copy to + * @src_page: source page + * @src_off: offset in page to copy from + * @len: length + * + * Both @dest_page/@dest_off and @src_page/@src_off must be mappable to a bus + * address according to the DMA mapping API rules for streaming mappings. + * Both @dest_page/@dest_off and @src_page/@src_off must stay memory resident + * (kernel memory or locked user space pages) + */ +static inline dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan, + struct page *dest_pg, unsigned int dest_off, struct page *src_pg, + unsigned int src_off, size_t len) +{ + int cpu = get_cpu(); + per_cpu_ptr(chan->local, cpu)->bytes_transferred += len; + per_cpu_ptr(chan->local, cpu)->memcpy_count++; + put_cpu(); + + return chan->device->device_memcpy_pg_to_pg(chan, dest_pg, dest_off, + src_pg, src_off, len); +} + +/** + * dma_async_memcpy_issue_pending - flush pending copies to HW + * @chan: + * + * This allows drivers to push copies to HW in batches, + * reducing MMIO writes where possible. + */ +static inline void dma_async_memcpy_issue_pending(struct dma_chan *chan) +{ + return chan->device->device_memcpy_issue_pending(chan); +} + +/** + * dma_async_memcpy_complete - poll for transaction completion + * @chan: DMA channel + * @cookie: transaction identifier to check status of + * @last: returns last completed cookie, can be NULL + * @used: returns last issued cookie, can be NULL + * + * If @last and @used are passed in, upon return they reflect the driver + * internal state and can be used with dma_async_is_complete() to check + * the status of multiple cookies without re-checking hardware state. + */ +static inline enum dma_status dma_async_memcpy_complete(struct dma_chan *chan, + dma_cookie_t cookie, dma_cookie_t *last, dma_cookie_t *used) +{ + return chan->device->device_memcpy_complete(chan, cookie, last, used); +} + +/** + * dma_async_is_complete - test a cookie against chan state + * @cookie: transaction identifier to test status of + * @last_complete: last know completed transaction + * @last_used: last cookie value handed out + * + * dma_async_is_complete() is used in dma_async_memcpy_complete() + * the test logic is seperated for lightweight testing of multiple cookies + */ +static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie, + dma_cookie_t last_complete, dma_cookie_t last_used) +{ + if (last_complete <= last_used) { + if ((cookie <= last_complete) || (cookie > last_used)) + return DMA_SUCCESS; + } else { + if ((cookie <= last_complete) && (cookie > last_used)) + return DMA_SUCCESS; + } + return DMA_IN_PROGRESS; +} + + +/* --- DMA device --- */ + +int dma_async_device_register(struct dma_device *device); +void dma_async_device_unregister(struct dma_device *device); + +#endif /* CONFIG_DMA_ENGINE */ +#endif /* DMAENGINE_H */ |