[PATCH v2 02/13] dmaengine: consolidate memcpy apis

From: Dan Williams
Date: Tue Oct 22 2013 - 17:11:22 EST


Copying from page to page (dma_async_memcpy_pg_to_pg) is the superset,
make the other two apis use that one in preparation for providing a
common dma unmap implementation. The common implementation just wants
to assume all buffers are mapped with dma_map_page().

Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
Cc: Tomasz Figa <t.figa@xxxxxxxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---

Resend to:
1/ add it to the new dmaengine patchwork
2/ cc maintainers of affected drivers
3/ fixup some mail addresses

drivers/dma/dmaengine.c | 137 +++++++++++++++--------------------------------
1 files changed, 45 insertions(+), 92 deletions(-)

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 9162ac80c18f..bbc89df6bc56 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -902,20 +902,23 @@ 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
+ * dma_async_memcpy_pg_to_pg - offloaded copy from page to page
* @chan: DMA channel to offload copy to
- * @dest: destination address (virtual)
- * @src: source address (virtual)
+ * @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 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).
+ * 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_buf_to_buf(struct dma_chan *chan, void *dest,
- void *src, size_t len)
+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;
@@ -923,16 +926,15 @@ dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest,
dma_cookie_t cookie;
unsigned long flags;

- dma_src = dma_map_single(dev->dev, src, len, DMA_TO_DEVICE);
- dma_dest = dma_map_single(dev->dev, dest, len, DMA_FROM_DEVICE);
- flags = DMA_CTRL_ACK |
- DMA_COMPL_SRC_UNMAP_SINGLE |
- DMA_COMPL_DEST_UNMAP_SINGLE;
+ dma_src = dma_map_page(dev->dev, src_pg, src_off, len, DMA_TO_DEVICE);
+ dma_dest = dma_map_page(dev->dev, dest_pg, dest_off, len,
+ DMA_FROM_DEVICE);
+ flags = DMA_CTRL_ACK;
tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags);

if (!tx) {
- dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
- dma_unmap_single(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
+ dma_unmap_page(dev->dev, dma_src, len, DMA_TO_DEVICE);
+ dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
return -ENOMEM;
}

@@ -946,6 +948,29 @@ dma_async_memcpy_buf_to_buf(struct dma_chan *chan, void *dest,

return cookie;
}
+EXPORT_SYMBOL(dma_async_memcpy_pg_to_pg);
+
+/**
+ * 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)
+{
+ return dma_async_memcpy_pg_to_pg(chan, virt_to_page(dest),
+ (unsigned long) dest & ~PAGE_MASK,
+ virt_to_page(src),
+ (unsigned long) src & ~PAGE_MASK, len);
+}
EXPORT_SYMBOL(dma_async_memcpy_buf_to_buf);

/**
@@ -963,86 +988,14 @@ EXPORT_SYMBOL(dma_async_memcpy_buf_to_buf);
*/
dma_cookie_t
dma_async_memcpy_buf_to_pg(struct dma_chan *chan, struct page *page,
- unsigned int offset, void *kdata, size_t len)
+ unsigned int offset, void *kdata, size_t len)
{
- struct dma_device *dev = chan->device;
- struct dma_async_tx_descriptor *tx;
- dma_addr_t dma_dest, dma_src;
- dma_cookie_t cookie;
- unsigned long flags;
-
- dma_src = dma_map_single(dev->dev, kdata, len, DMA_TO_DEVICE);
- dma_dest = dma_map_page(dev->dev, page, offset, len, DMA_FROM_DEVICE);
- flags = DMA_CTRL_ACK | DMA_COMPL_SRC_UNMAP_SINGLE;
- tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags);
-
- if (!tx) {
- dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
- dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
- return -ENOMEM;
- }
-
- tx->callback = NULL;
- cookie = tx->tx_submit(tx);
-
- preempt_disable();
- __this_cpu_add(chan->local->bytes_transferred, len);
- __this_cpu_inc(chan->local->memcpy_count);
- preempt_enable();
-
- return cookie;
+ return dma_async_memcpy_pg_to_pg(chan, page, offset,
+ virt_to_page(kdata),
+ (unsigned long) kdata & ~PAGE_MASK, len);
}
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 dma_dest, dma_src;
- dma_cookie_t cookie;
- unsigned long flags;
-
- dma_src = dma_map_page(dev->dev, src_pg, src_off, len, DMA_TO_DEVICE);
- dma_dest = dma_map_page(dev->dev, dest_pg, dest_off, len,
- DMA_FROM_DEVICE);
- flags = DMA_CTRL_ACK;
- tx = dev->device_prep_dma_memcpy(chan, dma_dest, dma_src, len, flags);
-
- if (!tx) {
- dma_unmap_page(dev->dev, dma_src, len, DMA_TO_DEVICE);
- dma_unmap_page(dev->dev, dma_dest, len, DMA_FROM_DEVICE);
- return -ENOMEM;
- }
-
- tx->callback = NULL;
- cookie = tx->tx_submit(tx);
-
- preempt_disable();
- __this_cpu_add(chan->local->bytes_transferred, len);
- __this_cpu_inc(chan->local->memcpy_count);
- preempt_enable();
-
- 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)
{

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