lk/linux-kernel-test
1
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

dmaengine: refactor dmaengine around dma_async_tx_descriptor

Browse Source 
The current dmaengine interface defines mutliple routines per operation,
i.e. dma_async_memcpy_buf_to_buf, dma_async_memcpy_buf_to_page etc.  Adding
more operation types (xor, crc, etc) to this model would result in an
unmanageable number of method permutations.

	Are we really going to add a set of hooks for each DMA engine
	whizbang feature?
		- Jeff Garzik

The descriptor creation process is refactored using the new common
dma_async_tx_descriptor structure.  Instead of per driver
do_<operation>_<dest>_to_<src> methods, drivers integrate
dma_async_tx_descriptor into their private software descriptor and then
define a 'prep' routine per operation.  The prep routine allocates a
descriptor and ensures that the tx_set_src, tx_set_dest, tx_submit routines
are valid.  Descriptor creation and submission becomes:

struct dma_device *dev;
struct dma_chan *chan;
struct dma_async_tx_descriptor *tx;

tx = dev->device_prep_dma_<operation>(chan, len, int_flag)
tx->tx_set_src(dma_addr_t, tx, index /* for multi-source ops */)
tx->tx_set_dest(dma_addr_t, tx, index)
tx->tx_submit(tx)

In addition to the refactoring, dma_async_tx_descriptor also lays the
groundwork for definining cross-channel-operation dependencies, and a
callback facility for asynchronous notification of operation completion.

Changelog:
* drop dma mapping methods, suggested by Chris Leech
* fix ioat_dma_dependency_added, also caught by Andrew Morton
* fix dma_sync_wait, change from Andrew Morton
* uninline large functions, change from Andrew Morton
* add tx->callback = NULL to dmaengine calls to interoperate with async_tx
  calls
* hookup ioat_tx_submit
* convert channel capabilities to a 'cpumask_t like' bitmap
* removed DMA_TX_ARRAY_INIT, no longer needed
* checkpatch.pl fixes
* make set_src, set_dest, and tx_submit descriptor specific methods
* fixup git-ioat merge
* move group_list and phys to dma_async_tx_descriptor

Cc: Jeff Garzik <jeff@garzik.org>
Cc: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dan Williams
2007-01-02 11:10:43 -07:00
parent 428ed6024f
commit 7405f74bad
4 changed files with 482 additions and 261 deletions
Download Patch File Download Diff File Expand all files Collapse all files

182
drivers/dma/dmaengine.c
View File

@@ -59,6 +59,7 @@
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/device.h>
#include <linux/dmaengine.h>
#include <linux/hardirq.h>
@@ -66,6 +67,7 @@
#include <linux/percpu.h>
#include <linux/rcupdate.h>
#include <linux/mutex.h>
#include <linux/jiffies.h>
static DEFINE_MUTEX(dma_list_mutex);
static LIST_HEAD(dma_device_list);
@@ -165,6 +167,24 @@ static struct dma_chan *dma_client_chan_alloc(struct dma_client *client)
return NULL;
}
enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
{
enum dma_status status;
unsigned long dma_sync_wait_timeout = jiffies + msecs_to_jiffies(5000);
dma_async_issue_pending(chan);
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");
return DMA_ERROR;
}
} while (status == DMA_IN_PROGRESS);
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
@@ -322,6 +342,25 @@ int dma_async_device_register(struct dma_device *device)
if (!device)
return -ENODEV;
/* validate device routines */
BUG_ON(dma_has_cap(DMA_MEMCPY, device->cap_mask) &&
!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_ZERO_SUM, device->cap_mask) &&
!device->device_prep_dma_interrupt);
BUG_ON(!device->device_alloc_chan_resources);
BUG_ON(!device->device_free_chan_resources);
BUG_ON(!device->device_dependency_added);
BUG_ON(!device->device_is_tx_complete);
BUG_ON(!device->device_issue_pending);
BUG_ON(!device->dev);
init_completion(&device->done);
kref_init(&device->refcount);
device->dev_id = id++;
@@ -415,6 +454,149 @@ void dma_async_device_unregister(struct dma_device *device)
}
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 addr;
dma_cookie_t cookie;
int cpu;
tx = dev->device_prep_dma_memcpy(chan, len, 0);
if (!tx)
return -ENOMEM;
tx->ack = 1;
tx->callback = NULL;
addr = dma_map_single(dev->dev, src, len, DMA_TO_DEVICE);
tx->tx_set_src(addr, tx, 0);
addr = dma_map_single(dev->dev, dest, len, DMA_FROM_DEVICE);
tx->tx_set_dest(addr, tx, 0);
cookie = tx->tx_submit(tx);
cpu = get_cpu();
per_cpu_ptr(chan->local, cpu)->bytes_transferred += len;
per_cpu_ptr(chan->local, cpu)->memcpy_count++;
put_cpu();
return cookie;
}
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)
{
struct dma_device *dev = chan->device;
struct dma_async_tx_descriptor *tx;
dma_addr_t addr;
dma_cookie_t cookie;
int cpu;
tx = dev->device_prep_dma_memcpy(chan, len, 0);
if (!tx)
return -ENOMEM;
tx->ack = 1;
tx->callback = NULL;
addr = dma_map_single(dev->dev, kdata, len, DMA_TO_DEVICE);
tx->tx_set_src(addr, tx, 0);
addr = dma_map_page(dev->dev, page, offset, len, DMA_FROM_DEVICE);
tx->tx_set_dest(addr, tx, 0);
cookie = tx->tx_submit(tx);
cpu = get_cpu();
per_cpu_ptr(chan->local, cpu)->bytes_transferred += len;
per_cpu_ptr(chan->local, cpu)->memcpy_count++;
put_cpu();
return cookie;
}
EXPORT_SYMBOL(dma_async_memcpy_buf_to_pg);
/**
* dma_async_memcpy_pg_to_pg - offloaded copy from page to page
* @chan: DMA channel to offload copy to
* @dest_pg: destination page
* @dest_off: offset in page to copy to
* @src_pg: 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).
*/
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)
{
struct dma_device *dev = chan->device;
struct dma_async_tx_descriptor *tx;
dma_addr_t addr;
dma_cookie_t cookie;
int cpu;
tx = dev->device_prep_dma_memcpy(chan, len, 0);
if (!tx)
return -ENOMEM;
tx->ack = 1;
tx->callback = NULL;
addr = dma_map_page(dev->dev, src_pg, src_off, len, DMA_TO_DEVICE);
tx->tx_set_src(addr, tx, 0);
addr = dma_map_page(dev->dev, dest_pg, dest_off, len, DMA_FROM_DEVICE);
tx->tx_set_dest(addr, tx, 0);
cookie = tx->tx_submit(tx);
cpu = get_cpu();
per_cpu_ptr(chan->local, cpu)->bytes_transferred += len;
per_cpu_ptr(chan->local, cpu)->memcpy_count++;
put_cpu();
return cookie;
}
EXPORT_SYMBOL(dma_async_memcpy_pg_to_pg);
void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
struct dma_chan *chan)
{
tx->chan = chan;
spin_lock_init(&tx->lock);
INIT_LIST_HEAD(&tx->depend_node);
INIT_LIST_HEAD(&tx->depend_list);
}
EXPORT_SYMBOL(dma_async_tx_descriptor_init);
static int __init dma_bus_init(void)
{
mutex_init(&dma_list_mutex);