* [RFC PATCH 1/2] dmaengine: add base support for the async_tx api
2007-06-02 0:17 [RFC PATCH 0/2] dmaengine: preparation for raid acceleration Dan Williams
@ 2007-06-02 0:17 ` Dan Williams
2007-06-02 0:17 ` [RFC PATCH 2/2] dmaengine: move channel management to the client Dan Williams
2007-06-27 7:54 ` [RFC PATCH 0/2] dmaengine: preparation for raid acceleration David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Dan Williams @ 2007-06-02 0:17 UTC (permalink / raw)
To: davem; +Cc: netdev, linux-kernel, christopher.leech
In preparation for the async_tx (dmaengine client) API this patch:
1/ introduces struct dma_async_tx_descriptor as a common field for all
dmaengine software descriptors. The primary role of this structure
is to enable callbacks at transaction completion time, and support
transaction chains that span multiple channels
2/ converts the device_memcpy_* methods into separate prep, set
src/dest, and submit stages
3/ adds support for capabilities beyond memcpy (xor, memset, xor zero
sum, completion interrupts). place holders for future capabilities
are also included
4/ converts ioatdma to the new semantics
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
Cc: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/dma/dmaengine.c | 182 +++++++++++++++++++++++++++++++++
drivers/dma/ioatdma.c | 248 ++++++++++++++++++++-------------------------
drivers/dma/ioatdma.h | 8 +
include/linux/dmaengine.h | 245 ++++++++++++++++++++++++++++----------------
4 files changed, 454 insertions(+), 229 deletions(-)
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 322ee29..8a49103 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 +342,28 @@ 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_tx_submit);
+ BUG_ON(!device->device_set_dest);
+ BUG_ON(!device->device_set_src);
+ 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 +439,146 @@ 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);
+ dev->device_set_src(addr, tx, 0);
+ addr = dma_map_single(dev->dev, dest, len, DMA_FROM_DEVICE);
+ dev->device_set_dest(addr, tx, 0);
+ cookie = dev->device_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);
+ dev->device_set_src(addr, tx, 0);
+ addr = dma_map_page(dev->dev, page, offset, len, DMA_FROM_DEVICE);
+ dev->device_set_dest(addr, tx, 0);
+ cookie = dev->device_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);
+ dev->device_set_src(addr, tx, 0);
+ addr = dma_map_page(dev->dev, dest_pg, dest_off, len, DMA_FROM_DEVICE);
+ dev->device_set_dest(addr, tx, 0);
+ cookie = dev->device_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 8e87261..343013d 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);
@@ -99,6 +100,8 @@ 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);
+ INIT_LIST_HEAD(&desc_sw->group_list);
desc_sw->hw = desc;
desc_sw->phys = phys;
@@ -215,45 +218,25 @@ 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 +253,8 @@ 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)
@@ -281,129 +263,90 @@ 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;
+ new->async_tx.type = DMA_MEMCPY;
- 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 >= 20) {
- 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)
+static void
+ioat_set_src(dma_addr_t addr, struct dma_async_tx_descriptor *tx, int index)
{
- dma_addr_t dest_addr;
- dma_addr_t src_addr;
- struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+ struct ioat_desc_sw *iter, *desc = tx_to_ioat_desc(tx);
+ struct ioat_dma_chan *ioat_chan = to_ioat_chan(tx->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);
+ pci_unmap_addr_set(desc, src, addr);
- return do_ioat_dma_memcpy(ioat_chan, dest_addr, src_addr, len);
-}
+ list_for_each_entry(iter, &desc->group_list, node) {
+ iter->hw->src_addr = addr;
+ addr += ioat_chan->xfercap;
+ }
-/**
- * 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)
+static void
+ioat_set_dest(dma_addr_t addr, struct dma_async_tx_descriptor *tx, int index)
{
- dma_addr_t dest_addr;
- dma_addr_t src_addr;
- struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+ struct ioat_desc_sw *iter, *desc = tx_to_ioat_desc(tx);
+ struct ioat_dma_chan *ioat_chan = to_ioat_chan(tx->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);
+ pci_unmap_addr_set(desc, dst, addr);
- return do_ioat_dma_memcpy(ioat_chan, dest_addr, src_addr, len);
+ list_for_each_entry(iter, &desc->group_list, node) {
+ iter->hw->dst_addr = addr;
+ addr += ioat_chan->xfercap;
+ }
}
-/**
- * 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)
+static dma_cookie_t
+ioat_tx_submit(struct dma_async_tx_descriptor *tx)
{
- dma_addr_t dest_addr;
- dma_addr_t src_addr;
- struct ioat_dma_chan *ioat_chan = to_ioat_chan(chan);
+ 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;
- 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);
+ /* 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 >= 20) {
+ append = 1;
+ ioat_chan->pending = 0;
+ }
+ spin_unlock_bh(&ioat_chan->desc_lock);
- return do_ioat_dma_memcpy(ioat_chan, dest_addr, src_addr, len);
+ if (append)
+ ioatdma_chan_write8(ioat_chan,
+ IOAT_CHANCMD_OFFSET,
+ IOAT_CHANCMD_APPEND);
+ return cookie;
}
/**
@@ -467,8 +410,8 @@ 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 +427,18 @@ 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 +454,17 @@ 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 +566,7 @@ 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 +593,8 @@ 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 +620,13 @@ 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 +722,17 @@ 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_set_src = ioat_set_src;
+ device->common.device_set_dest = ioat_set_dest;
+ 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.device_tx_submit = ioat_tx_submit;
+ 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..c62d63d 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 +64,46 @@ 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, /* when updating, make this the last entry and
+ * update the DMA_TX_ARRAY_INIT macro
+ */
+};
+
+/* last transaction type for creation of the capabilities mask */
+#define DMA_TX_TYPE_END (DMA_INTERRUPT + 1)
+
+/* helper macro for clients defining transaction arrays */
+#define DMA_TX_ARRAY_INIT(x) \
+ [DMA_MEMCPY] = x, \
+ [DMA_XOR] = x, \
+ [DMA_PQ_XOR] = x, \
+ [DMA_DUAL_XOR] = x, \
+ [DMA_PQ_UPDATE] = x, \
+ [DMA_ZERO_SUM] = x, \
+ [DMA_PQ_ZERO_SUM] = x, \
+ [DMA_MEMSET] = x, \
+ [DMA_MEMCPY_CRC32C] = x,\
+ [DMA_INTERRUPT] = x,
+
+/**
+ * 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 +196,101 @@ 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
+ * @type: allows backend implementations to key off the tx_type
+ * @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
+ * @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;
+ enum dma_transaction_type type;
+ dma_async_tx_callback callback;
+ void *callback_param;
+ struct dma_chan *chan;
+ 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_tx_submit: execute an operation
+ * @device_set_dest: set a destination address in a hardware descriptor
+ * @device_set_src: set a source address in a hardware descriptor
+ * @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);
+
+ dma_cookie_t (*device_tx_submit)(struct dma_async_tx_descriptor *tx);
+ void (*device_set_dest)(dma_addr_t addr,
+ struct dma_async_tx_descriptor *tx, int index);
+ void (*device_set_src)(dma_addr_t addr,
+ struct dma_async_tx_descriptor *tx, int index);
+ 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 +299,68 @@ 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)
+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);
+
+
+static inline void
+async_tx_ack(struct dma_async_tx_descriptor *tx)
{
- 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);
+ 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 +370,15 @@ 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 +401,7 @@ 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 +430,4 @@ 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 */
^ permalink raw reply related [flat|nested] 4+ messages in thread* [RFC PATCH 2/2] dmaengine: move channel management to the client
2007-06-02 0:17 [RFC PATCH 0/2] dmaengine: preparation for raid acceleration Dan Williams
2007-06-02 0:17 ` [RFC PATCH 1/2] dmaengine: add base support for the async_tx api Dan Williams
@ 2007-06-02 0:17 ` Dan Williams
2007-06-27 7:54 ` [RFC PATCH 0/2] dmaengine: preparation for raid acceleration David Miller
2 siblings, 0 replies; 4+ messages in thread
From: Dan Williams @ 2007-06-02 0:17 UTC (permalink / raw)
To: davem; +Cc: netdev, linux-kernel, christopher.leech
This effectively makes channels a shared resource rather than tying them
to a specific client. dmaengine now assumes that clients will internally
track how many channels they need and dmaengine will learn if the client cares about
a channel at dma_event_callback time. This also enables a client to ignore
a channel if it does not meet extra client specific constraints beyond
simple base capabilities.
This patch also fixes up the NET_DMA client to use the new mechanism.
Changelog:
* removed DMA_TX_ARRAY_INIT, no longer needed
* dma_client_chan_free -> dma_chan_release: switch to global reference
counting only at device unregistration time, before it was also happening
at client unregistration time
* clients now return dma_state_client to dmaengine (ack, dup, nak)
Cc: Chris Leech <christopher.leech@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
---
drivers/dma/dmaengine.c | 213 +++++++++++++++++++++++----------------------
drivers/dma/ioatdma.c | 1
drivers/dma/ioatdma.h | 3 -
include/linux/dmaengine.h | 75 ++++++++--------
net/core/dev.c | 111 ++++++++++++++++-------
5 files changed, 220 insertions(+), 183 deletions(-)
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 8a49103..927a8ac 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -37,11 +37,11 @@
* 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 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_put is done for each class_device registered. When the
+ * registered. A kref_get 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
@@ -51,10 +51,12 @@
* 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
+ * with a kref and a per_cpu local_t. A dma_chan_get is called when a client
+ * signals that it wants to use a channel, and dma_chan_put is called when
+ * a channel is removed or a client using it is unregesitered. A client can
+ * take extra references per outstanding transaction, as is the case with
+ * the NET DMA client. The release function does a kref_put on the device.
+ * -ChrisL, DanW
*/
#include <linux/init.h>
@@ -102,8 +104,18 @@ static ssize_t show_bytes_transferred(struct class_device *cd, char *buf)
static ssize_t show_in_use(struct class_device *cd, char *buf)
{
struct dma_chan *chan = container_of(cd, struct dma_chan, class_dev);
+ int in_use = 0;
+
+ if (unlikely(chan->slow_ref) && atomic_read(&chan->refcount.refcount) > 1)
+ in_use = 1;
+ else {
+ if (local_read(&(per_cpu_ptr(chan->local,
+ get_cpu())->refcount)) > 0)
+ in_use = 1;
+ put_cpu();
+ }
- return sprintf(buf, "%d\n", (chan->client ? 1 : 0));
+ return sprintf(buf, "%d\n", in_use);
}
static struct class_device_attribute dma_class_attrs[] = {
@@ -129,42 +141,50 @@ static struct class dma_devclass = {
/* --- client and device registration --- */
+#define dma_async_chan_satisfies_mask(chan, mask) __dma_async_chan_satisfies_mask((chan), &(mask))
+static int __dma_async_chan_satisfies_mask(struct dma_chan *chan, dma_cap_mask_t *want)
+{
+ dma_cap_mask_t has;
+
+ bitmap_and(has.bits, want->bits, chan->device->cap_mask.bits, DMA_TX_TYPE_END);
+ return bitmap_equal(want->bits, has.bits, DMA_TX_TYPE_END);
+}
+
/**
- * dma_client_chan_alloc - try to allocate a channel to a client
+ * dma_client_chan_alloc - try to allocate channels to a client
* @client: &dma_client
*
* Called with dma_list_mutex held.
*/
-static struct dma_chan *dma_client_chan_alloc(struct dma_client *client)
+static void dma_client_chan_alloc(struct dma_client *client)
{
struct dma_device *device;
struct dma_chan *chan;
- unsigned long flags;
int desc; /* allocated descriptor count */
+ enum dma_state_client ack;
- /* Find a channel, any DMA engine will do */
- list_for_each_entry(device, &dma_device_list, global_node) {
+ /* Find a channel */
+ list_for_each_entry(device, &dma_device_list, global_node)
list_for_each_entry(chan, &device->channels, device_node) {
- if (chan->client)
+ if (!dma_async_chan_satisfies_mask(chan, client->cap_mask))
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;
+ ack = client->event_callback(client,
+ chan,
+ DMA_RESOURCE_AVAILABLE);
+
+ /* we are done once this client rejects
+ * an available resource
+ */
+ if (ack == DMA_ACK) {
+ dma_chan_get(chan);
+ kref_get(&device->refcount);
+ } else if (ack == DMA_NAK)
+ return;
}
}
- }
-
- return NULL;
}
enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie)
@@ -193,7 +213,6 @@ 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);
}
EXPORT_SYMBOL(dma_chan_cleanup);
@@ -209,7 +228,7 @@ static void dma_chan_free_rcu(struct rcu_head *rcu)
kref_put(&chan->refcount, dma_chan_cleanup);
}
-static void dma_client_chan_free(struct dma_chan *chan)
+static void dma_chan_release(struct dma_chan *chan)
{
atomic_add(0x7FFFFFFF, &chan->refcount.refcount);
chan->slow_ref = 1;
@@ -217,70 +236,57 @@ static void dma_client_chan_free(struct dma_chan *chan)
}
/**
- * dma_chans_rebalance - reallocate channels to clients
- *
- * When the number of DMA channel in the system changes,
- * channels need to be rebalanced among clients.
+ * dma_chans_notify_available - broadcast available channels to the clients
*/
-static void dma_chans_rebalance(void)
+static void dma_clients_notify_available(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);
- }
- }
+ list_for_each_entry(client, &dma_client_list, global_node)
+ dma_client_chan_alloc(client);
mutex_unlock(&dma_list_mutex);
}
/**
- * dma_async_client_register - allocate and register a &dma_client
- * @event_callback: callback for notification of channel addition/removal
+ * dma_chans_notify_available - tell the clients that a channel is going away
+ * @chan: channel on its way out
*/
-struct dma_client *dma_async_client_register(dma_event_callback event_callback)
+static void dma_clients_notify_removed(struct dma_chan *chan)
{
struct dma_client *client;
+ enum dma_state_client ack;
- client = kzalloc(sizeof(*client), GFP_KERNEL);
- if (!client)
- return NULL;
+ mutex_lock(&dma_list_mutex);
+
+ list_for_each_entry(client, &dma_client_list, global_node) {
+ ack = client->event_callback(client, chan,
+ DMA_RESOURCE_REMOVED);
+
+ /* client was holding resources for this channel so
+ * free it
+ */
+ if (ack == DMA_ACK) {
+ dma_chan_put(chan);
+ kref_put(&chan->device->refcount,
+ dma_async_device_cleanup);
+ }
+ }
- INIT_LIST_HEAD(&client->channels);
- spin_lock_init(&client->lock);
- client->chans_desired = 0;
- client->chan_count = 0;
- client->event_callback = event_callback;
+ 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'
+ */
+void dma_async_client_register(struct dma_client *client)
+{
mutex_lock(&dma_list_mutex);
list_add_tail(&client->global_node, &dma_client_list);
mutex_unlock(&dma_list_mutex);
-
- return client;
}
EXPORT_SYMBOL(dma_async_client_register);
@@ -292,40 +298,42 @@ EXPORT_SYMBOL(dma_async_client_register);
*/
void dma_async_client_unregister(struct dma_client *client)
{
+ struct dma_device *device;
struct dma_chan *chan;
+ enum dma_state_client ack;
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);
+ /* free all channels the client is holding */
+ list_for_each_entry(device, &dma_device_list, global_node)
+ list_for_each_entry(chan, &device->channels, device_node) {
+ ack = client->event_callback(client, chan,
+ DMA_RESOURCE_REMOVED);
+
+ if (ack == DMA_ACK) {
+ dma_chan_put(chan);
+ kref_put(&chan->device->refcount,
+ dma_async_device_cleanup);
+ }
+ }
+
list_del(&client->global_node);
mutex_unlock(&dma_list_mutex);
-
- kfree(client);
- dma_chans_rebalance();
}
EXPORT_SYMBOL(dma_async_client_unregister);
/**
- * 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.
+ * 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,
- unsigned int number)
+void dma_async_client_chan_request(struct dma_client *client)
{
- client->chans_desired = number;
- dma_chans_rebalance();
+ mutex_lock(&dma_list_mutex);
+ dma_client_chan_alloc(client);
+ mutex_unlock(&dma_list_mutex);
}
EXPORT_SYMBOL(dma_async_client_chan_request);
@@ -381,6 +389,9 @@ int dma_async_device_register(struct dma_device *device)
device->dev_id, chan->chan_id);
kref_get(&device->refcount);
+ kref_init(&chan->refcount);
+ chan->slow_ref = 0;
+ INIT_RCU_HEAD(&chan->rcu);
class_device_register(&chan->class_dev);
}
@@ -388,7 +399,7 @@ int dma_async_device_register(struct dma_device *device)
list_add_tail(&device->global_node, &dma_device_list);
mutex_unlock(&dma_list_mutex);
- dma_chans_rebalance();
+ dma_clients_notify_available();
return 0;
}
@@ -413,26 +424,16 @@ static void dma_async_device_cleanup(struct kref *kref)
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);
- }
+ dma_clients_notify_removed(chan);
class_device_unregister(&chan->class_dev);
+ dma_chan_release(chan);
}
- dma_chans_rebalance();
kref_put(&device->refcount, dma_async_device_cleanup);
wait_for_completion(&device->done);
diff --git a/drivers/dma/ioatdma.c b/drivers/dma/ioatdma.c
index 343013d..56f8bb5 100644
--- a/drivers/dma/ioatdma.c
+++ b/drivers/dma/ioatdma.c
@@ -72,7 +72,6 @@ static int enumerate_dma_channels(struct ioat_device *device)
INIT_LIST_HEAD(&ioat_chan->used_desc);
/* This should be made common somewhere in dmaengine.c */
ioat_chan->common.device = &device->common;
- ioat_chan->common.client = NULL;
list_add_tail(&ioat_chan->common.device_node,
&device->common.channels);
}
diff --git a/drivers/dma/ioatdma.h b/drivers/dma/ioatdma.h
index fed259a..44d771d 100644
--- a/drivers/dma/ioatdma.h
+++ b/drivers/dma/ioatdma.h
@@ -30,9 +30,6 @@
#define IOAT_LOW_COMPLETION_MASK 0xffffffc0
-extern struct list_head dma_device_list;
-extern struct list_head dma_client_list;
-
/**
* struct ioat_device - internal representation of a IOAT device
* @pdev: PCI-Express device
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index c62d63d..f655a6e 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -29,20 +29,32 @@
#include <linux/dma-mapping.h>
/**
- * enum dma_event - resource PNP/power managment events
+ * enum dma_state - resource PNP/power managment state
* @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_AVAILABLE: DMA device available to the system
* @DMA_RESOURCE_REMOVED: DMA device removed from the system
*/
-enum dma_event {
+enum dma_state {
DMA_RESOURCE_SUSPEND,
DMA_RESOURCE_RESUME,
- DMA_RESOURCE_ADDED,
+ DMA_RESOURCE_AVAILABLE,
DMA_RESOURCE_REMOVED,
};
/**
+ * enum dma_state_client - state of the channel in the client
+ * @DMA_ACK: client would like to use, or was using this channel
+ * @DMA_DUP: client has already seen this channel, or is not using this channel
+ * @DMA_NAK: client does not want to see any more channels
+ */
+enum dma_state_client {
+ DMA_ACK,
+ DMA_DUP,
+ DMA_NAK,
+};
+
+/**
* typedef dma_cookie_t - an opaque DMA cookie
*
* if dma_cookie_t is >0 it's a DMA request cookie, <0 it's an error code
@@ -76,27 +88,12 @@ enum dma_transaction_type {
DMA_PQ_ZERO_SUM,
DMA_MEMSET,
DMA_MEMCPY_CRC32C,
- DMA_INTERRUPT, /* when updating, make this the last entry and
- * update the DMA_TX_ARRAY_INIT macro
- */
+ DMA_INTERRUPT, /* when updating, make this the last entry */
};
/* last transaction type for creation of the capabilities mask */
#define DMA_TX_TYPE_END (DMA_INTERRUPT + 1)
-/* helper macro for clients defining transaction arrays */
-#define DMA_TX_ARRAY_INIT(x) \
- [DMA_MEMCPY] = x, \
- [DMA_XOR] = x, \
- [DMA_PQ_XOR] = x, \
- [DMA_DUAL_XOR] = x, \
- [DMA_PQ_UPDATE] = x, \
- [DMA_ZERO_SUM] = x, \
- [DMA_PQ_ZERO_SUM] = x, \
- [DMA_MEMSET] = x, \
- [DMA_MEMCPY_CRC32C] = x,\
- [DMA_INTERRUPT] = x,
-
/**
* dma_cap_mask_t - capabilities bitmap modeled after cpumask_t.
* See linux/cpumask.h
@@ -119,7 +116,6 @@ struct dma_chan_percpu {
/**
* 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: channel ID for sysfs
@@ -127,12 +123,10 @@ struct dma_chan_percpu {
* @refcount: kref, used in "bigref" slow-mode
* @slow_ref: indicates that the DMA channel is free
* @rcu: the DMA channel's RCU head
- * @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;
@@ -144,11 +138,11 @@ struct dma_chan {
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)
@@ -173,26 +167,31 @@ static inline void dma_chan_put(struct dma_chan *chan)
/*
* typedef dma_event_callback - function pointer to a DMA event callback
+ * For each channel added to the system this routine is called for each client.
+ * If the client would like to use the channel it returns '1' to signal (ack)
+ * the dmaengine core to take out a reference on the channel and its
+ * corresponding device. A client must not 'ack' an available channel more
+ * than once. When a channel is removed all clients are notified. If a client
+ * is using the channel it must 'ack' the removal. A client must not 'ack' a
+ * removed channel more than once.
+ * @client - 'this' pointer for the client context
+ * @chan - channel to be acted upon
+ * @state - available or removed
*/
-typedef void (*dma_event_callback) (struct dma_client *client,
- struct dma_chan *chan, enum dma_event event);
+struct dma_client;
+typedef enum dma_state_client (*dma_event_callback) (struct dma_client *client,
+ struct dma_chan *chan, enum dma_state state);
/**
* 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
+ * @cap_mask: only return channels that satisfy the requested capabilities
+ * a value of zero corresponds to any capability
* @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;
+ dma_cap_mask_t cap_mask;
struct list_head global_node;
};
@@ -295,10 +294,9 @@ struct dma_device {
/* --- public DMA engine API --- */
-struct dma_client *dma_async_client_register(dma_event_callback event_callback);
+void dma_async_client_register(struct dma_client *client);
void dma_async_client_unregister(struct dma_client *client);
-void dma_async_client_chan_request(struct dma_client *client,
- unsigned int number);
+void dma_async_client_chan_request(struct dma_client *client);
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,
@@ -309,7 +307,6 @@ dma_cookie_t dma_async_memcpy_pg_to_pg(struct dma_chan *chan,
void dma_async_tx_descriptor_init(struct dma_async_tx_descriptor *tx,
struct dma_chan *chan);
-
static inline void
async_tx_ack(struct dma_async_tx_descriptor *tx)
{
diff --git a/net/core/dev.c b/net/core/dev.c
index 5a7f20f..41bcbce 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -151,9 +151,22 @@ static struct list_head ptype_base[16] __read_mostly; /* 16 way hashed list */
static struct list_head ptype_all __read_mostly; /* Taps */
#ifdef CONFIG_NET_DMA
-static struct dma_client *net_dma_client;
-static unsigned int net_dma_count;
-static spinlock_t net_dma_event_lock;
+struct net_dma {
+ struct dma_client client;
+ spinlock_t lock;
+ cpumask_t channel_mask;
+ struct dma_chan *channels[NR_CPUS];
+};
+
+static enum dma_state_client
+netdev_dma_event(struct dma_client *client, struct dma_chan *chan,
+ enum dma_state state);
+
+static struct net_dma net_dma = {
+ .client = {
+ .event_callback = netdev_dma_event,
+ },
+};
#endif
/*
@@ -2014,12 +2027,13 @@ out:
* There may not be any more sk_buffs coming right now, so push
* any pending DMA copies to hardware
*/
- if (net_dma_client) {
- struct dma_chan *chan;
- rcu_read_lock();
- list_for_each_entry_rcu(chan, &net_dma_client->channels, client_node)
- dma_async_memcpy_issue_pending(chan);
- rcu_read_unlock();
+ if (!cpus_empty(net_dma.channel_mask)) {
+ int chan_idx;
+ for_each_cpu_mask(chan_idx, net_dma.channel_mask) {
+ struct dma_chan *chan = net_dma.channels[chan_idx];
+ if (chan)
+ dma_async_memcpy_issue_pending(chan);
+ }
}
#endif
local_irq_enable();
@@ -3561,12 +3575,13 @@ static int dev_cpu_callback(struct notifier_block *nfb,
* This is called when the number of channels allocated to the net_dma_client
* changes. The net_dma_client tries to have one DMA channel per CPU.
*/
-static void net_dma_rebalance(void)
+
+static void net_dma_rebalance(struct net_dma *net_dma)
{
- unsigned int cpu, i, n;
+ unsigned int cpu, i, n, chan_idx;
struct dma_chan *chan;
- if (net_dma_count == 0) {
+ if (cpus_empty(net_dma->channel_mask)) {
for_each_online_cpu(cpu)
rcu_assign_pointer(per_cpu(softnet_data, cpu).net_dma, NULL);
return;
@@ -3574,11 +3589,12 @@ static void net_dma_rebalance(void)
i = 0;
cpu = first_cpu(cpu_online_map);
+
+ for_each_cpu_mask(chan_idx, net_dma->channel_mask) {
+ chan = net_dma->channels[chan_idx];
- rcu_read_lock();
- list_for_each_entry(chan, &net_dma_client->channels, client_node) {
- n = ((num_online_cpus() / net_dma_count)
- + (i < (num_online_cpus() % net_dma_count) ? 1 : 0));
+ n = ((num_online_cpus() / cpus_weight(net_dma->channel_mask))
+ + (i < (num_online_cpus() % cpus_weight(net_dma->channel_mask)) ? 1 : 0));
while(n) {
per_cpu(softnet_data, cpu).net_dma = chan;
@@ -3587,7 +3603,6 @@ static void net_dma_rebalance(void)
}
i++;
}
- rcu_read_unlock();
}
/**
@@ -3596,23 +3611,53 @@ static void net_dma_rebalance(void)
* @chan: DMA channel for the event
* @event: event type
*/
-static void netdev_dma_event(struct dma_client *client, struct dma_chan *chan,
- enum dma_event event)
-{
- spin_lock(&net_dma_event_lock);
- switch (event) {
- case DMA_RESOURCE_ADDED:
- net_dma_count++;
- net_dma_rebalance();
+static enum dma_state_client
+netdev_dma_event(struct dma_client *client, struct dma_chan *chan,
+ enum dma_state state)
+{
+ int i, found = 0, pos = -1;
+ struct net_dma *net_dma =
+ container_of(client, struct net_dma, client);
+ enum dma_state_client ack = DMA_DUP; /* default: take no action */
+
+ spin_lock(&net_dma->lock);
+ switch (state) {
+ case DMA_RESOURCE_AVAILABLE:
+ for (i = 0; i < NR_CPUS; i++)
+ if (net_dma->channels[i] == chan) {
+ found = 1;
+ break;
+ } else if (net_dma->channels[i] == NULL && pos < 0)
+ pos = i;
+
+ if (!found && pos >= 0) {
+ ack = DMA_ACK;
+ net_dma->channels[pos] = chan;
+ cpu_set(pos, net_dma->channel_mask);
+ net_dma_rebalance(net_dma);
+ }
break;
case DMA_RESOURCE_REMOVED:
- net_dma_count--;
- net_dma_rebalance();
+ for (i = 0; i < NR_CPUS; i++)
+ if (net_dma->channels[i] == chan) {
+ found = 1;
+ pos = i;
+ break;
+ }
+
+ if (found) {
+ ack = DMA_ACK;
+ cpu_clear(pos, net_dma->channel_mask);
+ net_dma->channels[i] = NULL;
+ net_dma_rebalance(net_dma);
+ }
break;
default:
break;
}
- spin_unlock(&net_dma_event_lock);
+ spin_unlock(&net_dma->lock);
+
+ return ack;
}
/**
@@ -3620,12 +3665,10 @@ static void netdev_dma_event(struct dma_client *client, struct dma_chan *chan,
*/
static int __init netdev_dma_register(void)
{
- spin_lock_init(&net_dma_event_lock);
- net_dma_client = dma_async_client_register(netdev_dma_event);
- if (net_dma_client == NULL)
- return -ENOMEM;
-
- dma_async_client_chan_request(net_dma_client, num_online_cpus());
+ spin_lock_init(&net_dma.lock);
+ dma_cap_set(DMA_MEMCPY, net_dma.client.cap_mask);
+ dma_async_client_register(&net_dma.client);
+ dma_async_client_chan_request(&net_dma.client);
return 0;
}
^ permalink raw reply related [flat|nested] 4+ messages in thread