[md-accel PATCH 01/19] dmaengine: refactor dmaengine around dma_async_tx_descriptor

Dan Williams
2007-06-27T01:51:27Z

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

Cc: Jeff Garzik <jeff@garzik.org>
Cc: Chris Leech <christopher.leech@intel.com>
Cc: Shannon Nelson <shannon.nelson@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---

drivers/dma/dmaengine.c | 182 ++++++++++++++++++++++++++++++
drivers/dma/ioatdma.c | 277 ++++++++++++++++++++-------------------------
drivers/dma/ioatdma.h | 8 +
include/linux/dmaengine.h | 230 +++++++++++++++++++++++--------------
4 files changed, 455 insertions(+), 242 deletions(-)

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 322ee29..379809f 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -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++;
@@ -397,6 +436,149 @@ 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);
diff --git a/drivers/dma/ioatdma.c b/drivers/dma/ioatdma.c
index fcbab07..6df2a3e 100644
--- a/drivers/dma/ioatdma.c
+++ b/drivers/dma/ioatdma.c
@@ -39,6 +39,7 @@
#define to_ioat_chan(chan) container_of(chan, struct ioat_dma_chan, common)
#define to_ioat_device(dev) container_of(dev, struct ioat_device, common)
#define to_ioat_desc(lh) container_of(lh, struct ioat_desc_sw, node)
+#define tx_to_ioat_desc(tx) container_of(tx, struct ioat_desc_sw, async_tx)

/* internal functions */
static int __devinit ioat_probe(struct pci_dev *pdev, const struct pci_device_id *ent);
@@ -78,6 +79,70 @@ static int enumerate_dma_channels(struct ioat_device *device)
return device->common.chancnt;
}

+static void
+ioat_set_src(dma_addr_t addr, struct dma_async_tx_descriptor *tx, int index)
+{
+ struct ioat_desc_sw *iter, *desc = tx_to_ioat_desc(tx);
+ struct ioat_dma_chan *ioat_chan = to_ioat_chan(tx->chan);
+
+ pci_unmap_addr_set(desc, src, addr);
+
+ list_for_each_entry(iter, &desc->group_list, node) {
+ iter->hw->src_addr = addr;
+ addr += ioat_chan->xfercap;
+ }
+
+}
+
+static void
+ioat_set_dest(dma_addr_t addr, struct dma_async_tx_descriptor *tx, int index)
+{
+ struct ioat_desc_sw *iter, *desc = tx_to_ioat_desc(tx);
+ struct ioat_dma_chan *ioat_chan = to_ioat_chan(tx->chan);
+
+ pci_unmap_addr_set(desc, dst, addr);
+
+ list_for_each_entry(iter, &desc->group_list, node) {
+ iter->hw->dst_addr = addr;
+ addr += ioat_chan->xfercap;
+ }
+}
+
+static dma_cookie_t
+ioat_tx_submit(struct dma_async_tx_descriptor *tx)
+{
+ struct ioat_dma_chan *ioat_chan = to_ioat_chan(tx->chan);
+ struct ioat_desc_sw *desc = tx_to_ioat_desc(tx);
+ struct ioat_desc_sw *group_start = list_entry(desc->group_list.next,
+ struct ioat_desc_sw, node);
+ int append = 0;
+ dma_cookie_t cookie;
+
+ spin_lock_bh(&ioat_chan->desc_lock);
+ /* cookie incr and addition to used_list must be atomic */
+ cookie = ioat_chan->common.cookie;
+ cookie++;
+ if (cookie < 0)
+ cookie = 1;
+ ioat_chan->common.cookie = desc->async_tx.cookie = cookie;
+
+ /* write address into NextDescriptor field of last desc in chain */
+ to_ioat_desc(ioat_chan->used_desc.prev)->hw->next = group_start->phys;
+ list_splice_init(&desc->group_list, ioat_chan->used_desc.prev);
+
+ ioat_chan->pending += desc->group_count;
+ if (ioat_chan->pending >= 4) {
+ append = 1;
+ ioat_chan->pending = 0;
+ }
+ spin_unlock_bh(&ioat_chan->desc_lock);
+
+ if (append)
+ ioatdma_chan_write8(ioat_chan, IOAT_CHANCMD_OFFSET,
+ IOAT_CHANCMD_APPEND);
+ return cookie;
+}
+
static struct ioat_desc_sw *ioat_dma_alloc_descriptor(
struct ioat_dma_chan *ioat_chan,
gfp_t flags)
@@ -99,6 +164,11 @@ static struct ioat_desc_sw *ioat_dma_alloc_descriptor(
}

memset(desc, 0, sizeof(*desc));
+ dma_async_tx_descriptor_init(&desc_sw->async_tx, &ioat_chan->common);
+ desc_sw->async_tx.tx_set_src = ioat_set_src;
+ desc_sw->async_tx.tx_set_dest = ioat_set_dest;
+ desc_sw->async_tx.tx_submit = ioat_tx_submit;
+ INIT_LIST_HEAD(&desc_sw->group_list);
desc_sw->hw = desc;
desc_sw->phys = phys;

@@ -215,45 +285,25 @@ static void ioat_dma_free_chan_resources(struct dma_chan *chan)
ioatdma_chan_write16(ioat_chan, IOAT_CHANCTRL_OFFSET, chanctrl);
}

-/**
- * do_ioat_dma_memcpy - actual function that initiates a IOAT DMA transaction
- * @ioat_chan: IOAT DMA channel handle
- * @dest: DMA destination address
- * @src: DMA source address
- * @len: transaction length in bytes
- */
-
-static dma_cookie_t do_ioat_dma_memcpy(struct ioat_dma_chan *ioat_chan,
- dma_addr_t dest,
- dma_addr_t src,
- size_t len)
+static struct dma_async_tx_descriptor *
+ioat_dma_prep_memcpy(struct dma_chan *chan, size_t len, int int_en)
{
- struct ioat_desc_sw *first;
- struct ioat_desc_sw *prev;
- struct ioat_desc_sw *new;
- dma_cookie_t cookie;
+ struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+ struct ioat_desc_sw *first, *prev, *new;
LIST_HEAD(new_chain);
u32 copy;
size_t orig_len;
- dma_addr_t orig_src, orig_dst;
- unsigned int desc_count = 0;
- unsigned int append = 0;
-
- if (!ioat_chan || !dest || !src)
- return -EFAULT;
+ int desc_count = 0;

if (!len)
- return ioat_chan->common.cookie;
+ return NULL;

orig_len = len;
- orig_src = src;
- orig_dst = dest;

first = NULL;
prev = NULL;

spin_lock_bh(&ioat_chan->desc_lock);
-
while (len) {
if (!list_empty(&ioat_chan->free_desc)) {
new = to_ioat_desc(ioat_chan->free_desc.next);
@@ -270,9 +320,8 @@ static dma_cookie_t do_ioat_dma_memcpy(struct ioat_dma_chan *ioat_chan,

new->hw->size = copy;
new->hw->ctl = 0;
- new->hw->src_addr = src;
- new->hw->dst_addr = dest;
- new->cookie = 0;
+ new->async_tx.cookie = 0;
+ new->async_tx.ack = 1;

/* chain together the physical address list for the HW */
if (!first)
@@ -281,130 +330,26 @@ static dma_cookie_t do_ioat_dma_memcpy(struct ioat_dma_chan *ioat_chan,
prev->hw->next = (u64) new->phys;

prev = new;
-
len -= copy;
- dest += copy;
- src += copy;
-
list_add_tail(&new->node, &new_chain);
desc_count++;
}
- new->hw->ctl = IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
- new->hw->next = 0;

- /* cookie incr and addition to used_list must be atomic */
+ list_splice(&new_chain, &new->group_list);

- cookie = ioat_chan->common.cookie;
- cookie++;
- if (cookie < 0)
- cookie = 1;
- ioat_chan->common.cookie = new->cookie = cookie;
+ new->hw->ctl = IOAT_DMA_DESCRIPTOR_CTL_CP_STS;
+ new->hw->next = 0;
+ new->group_count = desc_count;
+ new->async_tx.ack = 0; /* client is in control of this ack */
+ new->async_tx.cookie = -EBUSY;

- pci_unmap_addr_set(new, src, orig_src);
- pci_unmap_addr_set(new, dst, orig_dst);
pci_unmap_len_set(new, src_len, orig_len);
pci_unmap_len_set(new, dst_len, orig_len);
-
- /* write address into NextDescriptor field of last desc in chain */
- to_ioat_desc(ioat_chan->used_desc.prev)->hw->next = first->phys;
- list_splice_init(&new_chain, ioat_chan->used_desc.prev);
-
- ioat_chan->pending += desc_count;
- if (ioat_chan->pending >= 4) {
- append = 1;
- ioat_chan->pending = 0;
- }
-
spin_unlock_bh(&ioat_chan->desc_lock);

- if (append)
- ioatdma_chan_write8(ioat_chan,
- IOAT_CHANCMD_OFFSET,
- IOAT_CHANCMD_APPEND);
- return cookie;
+ return new ? &new->async_tx : NULL;
}

-/**
- * ioat_dma_memcpy_buf_to_buf - wrapper that takes src & dest bufs
- * @chan: IOAT DMA channel handle
- * @dest: DMA destination address
- * @src: DMA source address
- * @len: transaction length in bytes
- */
-
-static dma_cookie_t ioat_dma_memcpy_buf_to_buf(struct dma_chan *chan,
- void *dest,
- void *src,
- size_t len)
-{
- dma_addr_t dest_addr;
- dma_addr_t src_addr;
- struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
-
- dest_addr = pci_map_single(ioat_chan->device->pdev,
- dest, len, PCI_DMA_FROMDEVICE);
- src_addr = pci_map_single(ioat_chan->device->pdev,
- src, len, PCI_DMA_TODEVICE);
-
- return do_ioat_dma_memcpy(ioat_chan, dest_addr, src_addr, len);
-}
-
-/**
- * ioat_dma_memcpy_buf_to_pg - wrapper, copying from a buf to a page
- * @chan: IOAT DMA channel handle
- * @page: pointer to the page to copy to
- * @offset: offset into that page
- * @src: DMA source address
- * @len: transaction length in bytes
- */
-
-static dma_cookie_t ioat_dma_memcpy_buf_to_pg(struct dma_chan *chan,
- struct page *page,
- unsigned int offset,
- void *src,
- size_t len)
-{
- dma_addr_t dest_addr;
- dma_addr_t src_addr;
- struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
-
- dest_addr = pci_map_page(ioat_chan->device->pdev,
- page, offset, len, PCI_DMA_FROMDEVICE);
- src_addr = pci_map_single(ioat_chan->device->pdev,
- src, len, PCI_DMA_TODEVICE);
-
- return do_ioat_dma_memcpy(ioat_chan, dest_addr, src_addr, len);
-}
-
-/**
- * ioat_dma_memcpy_pg_to_pg - wrapper, copying between two pages
- * @chan: IOAT DMA channel handle
- * @dest_pg: pointer to the page to copy to
- * @dest_off: offset into that page
- * @src_pg: pointer to the page to copy from
- * @src_off: offset into that page
- * @len: transaction length in bytes. This is guaranteed not to make a copy
- * across a page boundary.
- */
-
-static dma_cookie_t ioat_dma_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)
-{
- dma_addr_t dest_addr;
- dma_addr_t src_addr;
- struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
-
- dest_addr = pci_map_page(ioat_chan->device->pdev,
- dest_pg, dest_off, len, PCI_DMA_FROMDEVICE);
- src_addr = pci_map_page(ioat_chan->device->pdev,
- src_pg, src_off, len, PCI_DMA_TODEVICE);
-
- return do_ioat_dma_memcpy(ioat_chan, dest_addr, src_addr, len);
-}

/**
* ioat_dma_memcpy_issue_pending - push potentially unrecognized appended descriptors to hw
@@ -467,8 +412,8 @@ static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *chan)
* exceeding xfercap, perhaps. If so, only the last one will
* have a cookie, and require unmapping.
*/
- if (desc->cookie) {
- cookie = desc->cookie;
+ if (desc->async_tx.cookie) {
+ cookie = desc->async_tx.cookie;

/* yes we are unmapping both _page and _single alloc'd
regions with unmap_page. Is this *really* that bad?
@@ -484,13 +429,18 @@ static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *chan)
}

if (desc->phys != phys_complete) {
- /* a completed entry, but not the last, so cleanup */
- list_del(&desc->node);
- list_add_tail(&desc->node, &chan->free_desc);
+ /* a completed entry, but not the last, so cleanup
+ * if the client is done with the descriptor
+ */
+ if (desc->async_tx.ack) {
+ list_del(&desc->node);
+ list_add_tail(&desc->node, &chan->free_desc);
+ } else
+ desc->async_tx.cookie = 0;
} else {
/* last used desc. Do not remove, so we can append from
it, but don't look at it next time, either */
- desc->cookie = 0;
+ desc->async_tx.cookie = 0;

/* TODO check status bits? */
break;
@@ -506,6 +456,17 @@ static void ioat_dma_memcpy_cleanup(struct ioat_dma_chan *chan)
spin_unlock(&chan->cleanup_lock);
}

+static void ioat_dma_dependency_added(struct dma_chan *chan)
+{
+ struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+ spin_lock_bh(&ioat_chan->desc_lock);
+ if (ioat_chan->pending == 0) {
+ spin_unlock_bh(&ioat_chan->desc_lock);
+ ioat_dma_memcpy_cleanup(ioat_chan);
+ } else
+ spin_unlock_bh(&ioat_chan->desc_lock);
+}
+
/**
* ioat_dma_is_complete - poll the status of a IOAT DMA transaction
* @chan: IOAT DMA channel handle
@@ -607,6 +568,7 @@ static void ioat_start_null_desc(struct ioat_dma_chan *ioat_chan)

desc->hw->ctl = IOAT_DMA_DESCRIPTOR_NUL;
desc->hw->next = 0;
+ desc->async_tx.ack = 1;

list_add_tail(&desc->node, &ioat_chan->used_desc);
spin_unlock_bh(&ioat_chan->desc_lock);
@@ -633,6 +595,8 @@ static int ioat_self_test(struct ioat_device *device)
u8 *src;
u8 *dest;
struct dma_chan *dma_chan;
+ struct dma_async_tx_descriptor *tx;
+ dma_addr_t addr;
dma_cookie_t cookie;
int err = 0;

@@ -658,7 +622,15 @@ static int ioat_self_test(struct ioat_device *device)
goto out;
}

- cookie = ioat_dma_memcpy_buf_to_buf(dma_chan, dest, src, IOAT_TEST_SIZE);
+ tx = ioat_dma_prep_memcpy(dma_chan, IOAT_TEST_SIZE, 0);
+ async_tx_ack(tx);
+ addr = dma_map_single(dma_chan->device->dev, src, IOAT_TEST_SIZE,
+ DMA_TO_DEVICE);
+ ioat_set_src(addr, tx, 0);
+ addr = dma_map_single(dma_chan->device->dev, dest, IOAT_TEST_SIZE,
+ DMA_FROM_DEVICE);
+ ioat_set_dest(addr, tx, 0);
+ cookie = ioat_tx_submit(tx);
ioat_dma_memcpy_issue_pending(dma_chan);
msleep(1);

@@ -754,13 +726,14 @@ static int __devinit ioat_probe(struct pci_dev *pdev,
INIT_LIST_HEAD(&device->common.channels);
enumerate_dma_channels(device);

+ dma_cap_set(DMA_MEMCPY, device->common.cap_mask);
device->common.device_alloc_chan_resources = ioat_dma_alloc_chan_resources;
device->common.device_free_chan_resources = ioat_dma_free_chan_resources;
- device->common.device_memcpy_buf_to_buf = ioat_dma_memcpy_buf_to_buf;
- device->common.device_memcpy_buf_to_pg = ioat_dma_memcpy_buf_to_pg;
- device->common.device_memcpy_pg_to_pg = ioat_dma_memcpy_pg_to_pg;
- device->common.device_memcpy_complete = ioat_dma_is_complete;
- device->common.device_memcpy_issue_pending = ioat_dma_memcpy_issue_pending;
+ device->common.device_prep_dma_memcpy = ioat_dma_prep_memcpy;
+ device->common.device_is_tx_complete = ioat_dma_is_complete;
+ device->common.device_issue_pending = ioat_dma_memcpy_issue_pending;
+ device->common.device_dependency_added = ioat_dma_dependency_added;
+ device->common.dev = &pdev->dev;
printk(KERN_INFO "Intel(R) I/OAT DMA Engine found, %d channels\n",
device->common.chancnt);

diff --git a/drivers/dma/ioatdma.h b/drivers/dma/ioatdma.h
index 62b26a9..fed259a 100644
--- a/drivers/dma/ioatdma.h
+++ b/drivers/dma/ioatdma.h
@@ -105,15 +105,20 @@ struct ioat_dma_chan {
/**
* struct ioat_desc_sw - wrapper around hardware descriptor
* @hw: hardware DMA descriptor
+ * @async_tx:
* @node:
+ * @group_list:
+ * @group_cnt:
* @cookie:
* @phys:
*/

struct ioat_desc_sw {
struct ioat_dma_descriptor *hw;
+ struct dma_async_tx_descriptor async_tx;
struct list_head node;
- dma_cookie_t cookie;
+ struct list_head group_list;
+ int group_count;
dma_addr_t phys;
DECLARE_PCI_UNMAP_ADDR(src)
DECLARE_PCI_UNMAP_LEN(src_len)
@@ -122,4 +127,3 @@ struct ioat_desc_sw {
};

#endif /* IOATDMA_H */
-
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index c94d8f1..0f21375 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -21,13 +21,12 @@
#ifndef DMAENGINE_H
#define DMAENGINE_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>
+#include <linux/dma-mapping.h>

/**
* enum dma_event - resource PNP/power managment events
@@ -65,6 +64,31 @@ enum dma_status {
};

/**
+ * enum dma_transaction_type - DMA transaction types/indexes
+ */
+enum dma_transaction_type {
+ DMA_MEMCPY,
+ DMA_XOR,
+ DMA_PQ_XOR,
+ DMA_DUAL_XOR,
+ DMA_PQ_UPDATE,
+ DMA_ZERO_SUM,
+ DMA_PQ_ZERO_SUM,
+ DMA_MEMSET,
+ DMA_MEMCPY_CRC32C,
+ DMA_INTERRUPT,
+};
+
+/* last transaction type for creation of the capabilities mask */
+#define DMA_TX_TYPE_END (DMA_INTERRUPT + 1)
+
+/**
+ * dma_cap_mask_t - capabilities bitmap modeled after cpumask_t.
+ * See linux/cpumask.h
+ */
+typedef struct { DECLARE_BITMAP(bits, DMA_TX_TYPE_END); } dma_cap_mask_t;
+
+/**
* 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
@@ -157,48 +181,99 @@ struct dma_client {
struct list_head global_node;
};

+typedef void (*dma_async_tx_callback)(void *dma_async_param);
+/**
+ * struct dma_async_tx_descriptor - async transaction descriptor
+ * @cookie: tracking cookie for this transaction, set to -EBUSY if
+ * this tx is sitting on a dependency list
+ * @ack: the descriptor can not be reused until the client acknowledges
+ * receipt, i.e. has has a chance to establish any dependency chains
+ * @callback: routine to call after this operation is complete
+ * @callback_param: general parameter to pass to the callback routine
+ * @chan: target channel for this operation
+ * @tx_submit: execute an operation
+ * @tx_set_dest: set a destination address in a hardware descriptor
+ * @tx_set_src: set a source address in a hardware descriptor
+ * @depend_list: at completion this list of transactions are submitted
+ * @depend_node: allow this transaction to be executed after another
+ * transaction has completed
+ * @parent: pointer to the next level up in the dependency chain
+ * @lock: protect the dependency list
+ */
+struct dma_async_tx_descriptor {
+ dma_cookie_t cookie;
+ int ack;
+ dma_async_tx_callback callback;
+ void *callback_param;
+ struct dma_chan *chan;
+ dma_cookie_t (*tx_submit)(struct dma_async_tx_descriptor *tx);
+ void (*tx_set_dest)(dma_addr_t addr,
+ struct dma_async_tx_descriptor *tx, int index);
+ void (*tx_set_src)(dma_addr_t addr,
+ struct dma_async_tx_descriptor *tx, int index);
+ struct list_head depend_list;
+ struct list_head depend_node;
+ struct dma_async_tx_descriptor *parent;
+ spinlock_t lock;
+};
+
/**
* 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
+ * @cap_mask: one or more dma_capability flags
+ * @max_xor: maximum number of xor sources, 0 if no capability
* @refcount: reference count
* @done: IO completion struct
* @dev_id: unique device ID
+ * @dev: struct device reference for dma mapping api
* @device_alloc_chan_resources: allocate resources and return the
* number of allocated descriptors
* @device_free_chan_resources: release DMA channel's resources
- * @device_memcpy_buf_to_buf: memcpy buf pointer to buf pointer
- * @device_memcpy_buf_to_pg: memcpy buf pointer to struct page
- * @device_memcpy_pg_to_pg: memcpy struct page/offset to struct page/offset
- * @device_memcpy_complete: poll the status of an IOAT DMA transaction
- * @device_memcpy_issue_pending: push appended descriptors to hardware
+ * @device_prep_dma_memcpy: prepares a memcpy operation
+ * @device_prep_dma_xor: prepares a xor operation
+ * @device_prep_dma_zero_sum: prepares a zero_sum operation
+ * @device_prep_dma_memset: prepares a memset operation
+ * @device_prep_dma_interrupt: prepares an end of chain interrupt operation
+ * @device_dependency_added: async_tx notifies the channel about new deps
+ * @device_issue_pending: push pending transactions to hardware
*/
struct dma_device {

unsigned int chancnt;
struct list_head channels;
struct list_head global_node;
+ dma_cap_mask_t cap_mask;
+ int max_xor;

struct kref refcount;
struct completion done;

int dev_id;
+ struct device *dev;

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,
+
+ struct dma_async_tx_descriptor *(*device_prep_dma_memcpy)(
+ struct dma_chan *chan, size_t len, int int_en);
+ struct dma_async_tx_descriptor *(*device_prep_dma_xor)(
+ struct dma_chan *chan, unsigned int src_cnt, size_t len,
+ int int_en);
+ struct dma_async_tx_descriptor *(*device_prep_dma_zero_sum)(
+ struct dma_chan *chan, unsigned int src_cnt, size_t len,
+ u32 *result, int int_en);
+ struct dma_async_tx_descriptor *(*device_prep_dma_memset)(
+ struct dma_chan *chan, int value, size_t len, int int_en);
+ struct dma_async_tx_descriptor *(*device_prep_dma_interrupt)(
+ struct dma_chan *chan);
+
+ void (*device_dependency_added)(struct dma_chan *chan);
+ enum dma_status (*device_is_tx_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);
+ void (*device_issue_pending)(struct dma_chan *chan);
};

/* --- public DMA engine API --- */
@@ -207,96 +282,72 @@ 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_cookie_t dma_async_memcpy_buf_to_buf(struct dma_chan *chan,
+ void *dest, void *src, size_t len);
+dma_cookie_t dma_async_memcpy_buf_to_pg(struct dma_chan *chan,
+ struct page *page, unsigned int offset, void *kdata, size_t len);
+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);
+void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
+ struct dma_chan *chan);

-/**
- * 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);
+static inline void
+async_tx_ack(struct dma_async_tx_descriptor *tx)
+{
+ tx->ack = 1;
}

-/**
- * 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)
- */
-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)
+#define first_dma_cap(mask) __first_dma_cap(&(mask))
+static inline int __first_dma_cap(const dma_cap_mask_t *srcp)
{
- int cpu = get_cpu();
- per_cpu_ptr(chan->local, cpu)->bytes_transferred += len;
- per_cpu_ptr(chan->local, cpu)->memcpy_count++;
- put_cpu();
+ return min_t(int, DMA_TX_TYPE_END,
+ find_first_bit(srcp->bits, DMA_TX_TYPE_END));
+}

- return chan->device->device_memcpy_buf_to_pg(chan, page, offset,
- kdata, len);
+#define next_dma_cap(n, mask) __next_dma_cap((n), &(mask))
+static inline int __next_dma_cap(int n, const dma_cap_mask_t *srcp)
+{
+ return min_t(int, DMA_TX_TYPE_END,
+ find_next_bit(srcp->bits, DMA_TX_TYPE_END, n+1));
}

-/**
- * 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).
- */
-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)
+#define dma_cap_set(tx, mask) __dma_cap_set((tx), &(mask))
+static inline void
+__dma_cap_set(enum dma_transaction_type tx_type, dma_cap_mask_t *dstp)
{
- int cpu = get_cpu();
- per_cpu_ptr(chan->local, cpu)->bytes_transferred += len;
- per_cpu_ptr(chan->local, cpu)->memcpy_count++;
- put_cpu();
+ set_bit(tx_type, dstp->bits);
+}

- return chan->device->device_memcpy_pg_to_pg(chan, dest_pg, dest_off,
- src_pg, src_off, len);
+#define dma_has_cap(tx, mask) __dma_has_cap((tx), &(mask))
+static inline int
+__dma_has_cap(enum dma_transaction_type tx_type, dma_cap_mask_t *srcp)
+{
+ return test_bit(tx_type, srcp->bits);
}

+#define for_each_dma_cap_mask(cap, mask) \
+ for ((cap) = first_dma_cap(mask); \
+ (cap) < DMA_TX_TYPE_END; \
+ (cap) = next_dma_cap((cap), (mask)))
+
/**
- * dma_async_memcpy_issue_pending - flush pending copies to HW
+ * dma_async_issue_pending - flush pending transactions to HW
* @chan: target DMA channel
*
* 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)
+static inline void dma_async_issue_pending(struct dma_chan *chan)
{
- return chan->device->device_memcpy_issue_pending(chan);
+ return chan->device->device_issue_pending(chan);
}

+#define dma_async_memcpy_issue_pending(chan) dma_async_issue_pending(chan)
+
/**
- * dma_async_memcpy_complete - poll for transaction completion
+ * dma_async_is_tx_complete - poll for transaction completion
* @chan: DMA channel
* @cookie: transaction identifier to check status of
* @last: returns last completed cookie, can be NULL
@@ -306,12 +357,15 @@ static inline void dma_async_memcpy_issue_pending(struct dma_chan *chan)
* 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,
+static inline enum dma_status dma_async_is_tx_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);
+ return chan->device->device_is_tx_complete(chan, cookie, last, used);
}

+#define dma_async_memcpy_complete(chan, cookie, last, used)\
+ dma_async_is_tx_complete(chan, cookie, last, used)
+
/**
* dma_async_is_complete - test a cookie against chan state
* @cookie: transaction identifier to test status of
@@ -334,6 +388,7 @@ static inline enum dma_status dma_async_is_complete(dma_cookie_t cookie,
return DMA_IN_PROGRESS;
}

+enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie);

/* --- DMA device --- */

@@ -362,5 +417,4 @@ dma_cookie_t dma_memcpy_pg_to_iovec(struct dma_chan *chan, struct iovec *iov,
struct dma_pinned_list *pinned_list, struct page *page,
unsigned int offset, size_t len);

-#endif /* CONFIG_DMA_ENGINE */
#endif /* DMAENGINE_H */