[PATCH v2 11/13] NTB: convert to dmaengine_unmap_data

From: Dan Williams
Date: Tue Oct 22 2013 - 17:09:39 EST


From: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>

Use the generic unmap object to unmap dma buffers.

As NTB can be compiled without DMA_ENGINE support add
stub functions to <linux/dmaengine.h> for dma_set_unmap(),
dmaengine_get_unmap_data() and dmaengine_unmap_put().

Cc: Dan Williams <dan.j.williams@xxxxxxxxx>
Cc: Vinod Koul <vinod.koul@xxxxxxxxx>
Cc: Tomasz Figa <t.figa@xxxxxxxxxxx>
Cc: Dave Jiang <dave.jiang@xxxxxxxxx>
Cc: Jon Mason <jon.mason@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/ntb/ntb_transport.c | 63 +++++++++++++++++++++++++++++++------------
include/linux/dmaengine.h | 15 ++++++++++
2 files changed, 61 insertions(+), 17 deletions(-)

diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 12a9e83c008b..fc6bbf1e16d9 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -1034,7 +1034,7 @@ static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset,
struct dma_chan *chan = qp->dma_chan;
struct dma_device *device;
size_t pay_off, buff_off;
- dma_addr_t src, dest;
+ struct dmaengine_unmap_data *unmap;
dma_cookie_t cookie;
void *buf = entry->buf;
unsigned long flags;
@@ -1054,27 +1054,41 @@ static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset,
if (!is_dma_copy_aligned(device, pay_off, buff_off, len))
goto err1;

- dest = dma_map_single(device->dev, buf, len, DMA_FROM_DEVICE);
- if (dma_mapping_error(device->dev, dest))
+ unmap = dmaengine_get_unmap_data(device->dev, 2, GFP_NOIO);
+ if (!unmap)
goto err1;

- src = dma_map_single(device->dev, offset, len, DMA_TO_DEVICE);
- if (dma_mapping_error(device->dev, src))
+ unmap->addr[0] = dma_map_page(device->dev, virt_to_page(offset),
+ pay_off, len, DMA_TO_DEVICE);
+ if (dma_mapping_error(device->dev, unmap->addr[0]))
goto err2;

- flags = DMA_COMPL_DEST_UNMAP_SINGLE | DMA_COMPL_SRC_UNMAP_SINGLE |
+ unmap->to_cnt = 1;
+
+ unmap->addr[1] = dma_map_page(device->dev, virt_to_page(buf),
+ buff_off, len, DMA_FROM_DEVICE);
+ if (dma_mapping_error(device->dev, unmap->addr[1]))
+ goto err2;
+
+ unmap->from_cnt = 1;
+
+ flags = DMA_COMPL_SKIP_SRC_UNMAP | DMA_COMPL_SKIP_DEST_UNMAP |
DMA_PREP_INTERRUPT;
- txd = device->device_prep_dma_memcpy(chan, dest, src, len, flags);
+ txd = device->device_prep_dma_memcpy(chan, unmap->addr[1],
+ unmap->addr[0], len, flags);
if (!txd)
- goto err3;
+ goto err2;

txd->callback = ntb_rx_copy_callback;
txd->callback_param = entry;
+ dma_set_unmap(txd, unmap);

cookie = dmaengine_submit(txd);
if (dma_submit_error(cookie))
goto err3;

+ dmaengine_unmap_put(unmap);
+
qp->last_cookie = cookie;

qp->rx_async++;
@@ -1082,9 +1096,9 @@ static void ntb_async_rx(struct ntb_queue_entry *entry, void *offset,
return;

err3:
- dma_unmap_single(device->dev, src, len, DMA_TO_DEVICE);
+ dmaengine_unmap_put(unmap);
err2:
- dma_unmap_single(device->dev, dest, len, DMA_FROM_DEVICE);
+ dmaengine_unmap_put(unmap);
err1:
/* If the callbacks come out of order, the writing of the index to the
* last completed will be out of order. This may result in the
@@ -1245,7 +1259,8 @@ static void ntb_async_tx(struct ntb_transport_qp *qp,
struct dma_chan *chan = qp->dma_chan;
struct dma_device *device;
size_t dest_off, buff_off;
- dma_addr_t src, dest;
+ struct dmaengine_unmap_data *unmap;
+ dma_addr_t dest;
dma_cookie_t cookie;
void __iomem *offset;
size_t len = entry->len;
@@ -1273,28 +1288,42 @@ static void ntb_async_tx(struct ntb_transport_qp *qp,
if (!is_dma_copy_aligned(device, buff_off, dest_off, len))
goto err;

- src = dma_map_single(device->dev, buf, len, DMA_TO_DEVICE);
- if (dma_mapping_error(device->dev, src))
+ unmap = dmaengine_get_unmap_data(device->dev, 1, GFP_NOIO);
+ if (!unmap)
goto err;

- flags = DMA_COMPL_SRC_UNMAP_SINGLE | DMA_PREP_INTERRUPT;
- txd = device->device_prep_dma_memcpy(chan, dest, src, len, flags);
+ unmap->addr[0] = dma_map_page(device->dev, virt_to_page(buf),
+ buff_off, len, DMA_TO_DEVICE);
+ if (dma_mapping_error(device->dev, unmap->addr[0]))
+ goto err1;
+
+ unmap->to_cnt = 1;
+
+ flags = DMA_COMPL_SKIP_SRC_UNMAP | DMA_COMPL_SKIP_DEST_UNMAP |
+ DMA_PREP_INTERRUPT;
+ txd = device->device_prep_dma_memcpy(chan, dest, unmap->addr[0], len,
+ flags);
if (!txd)
goto err1;

txd->callback = ntb_tx_copy_callback;
txd->callback_param = entry;
+ dma_set_unmap(txd, unmap);

cookie = dmaengine_submit(txd);
if (dma_submit_error(cookie))
- goto err1;
+ goto err2;
+
+ dmaengine_unmap_put(unmap);

dma_async_issue_pending(chan);
qp->tx_async++;

return;
+err2:
+ dmaengine_unmap_put(unmap);
err1:
- dma_unmap_single(device->dev, src, len, DMA_TO_DEVICE);
+ dmaengine_unmap_put(unmap);
err:
ntb_memcpy_tx(entry, offset);
qp->tx_memcpy++;
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index dc98bc5d4929..3782cdb782a8 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -457,6 +457,7 @@ struct dma_async_tx_descriptor {
#endif
};

+#ifdef CONFIG_DMA_ENGINE
static inline void dma_set_unmap(struct dma_async_tx_descriptor *tx,
struct dmaengine_unmap_data *unmap)
{
@@ -467,6 +468,20 @@ static inline void dma_set_unmap(struct dma_async_tx_descriptor *tx,
struct dmaengine_unmap_data *
dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags);
void dmaengine_unmap_put(struct dmaengine_unmap_data *unmap);
+#else
+static inline void dma_set_unmap(struct dma_async_tx_descriptor *tx,
+ struct dmaengine_unmap_data *unmap)
+{
+}
+static inline struct dmaengine_unmap_data *
+dmaengine_get_unmap_data(struct device *dev, int nr, gfp_t flags)
+{
+ return NULL;
+}
+static inline void dmaengine_unmap_put(struct dmaengine_unmap_data *unmap)
+{
+}
+#endif

static inline void dma_descriptor_unmap(struct dma_async_tx_descriptor *tx)
{

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