linux-kernel - [PATCH 11/20] async_tx: do DMA unmap in core for MEMSET operations

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Date:	Mon, 05 Nov 2012 11:00:22 +0100
From:	Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
To:	linux-kernel@...r.kernel.org
Cc:	djbw@...com, dwmw2@...radead.org, hskinnemoen@...il.com,
	iws@...o.caltech.edu, vinod.koul@...el.com, vipin.kumar@...com,
	t.figa@...sung.com, kyungmin.park@...sung.com,
	Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
Subject: [PATCH 11/20] async_tx: do DMA unmap in core for MEMSET operations

Convert core async_tx code (async_memset()) to do DMA unmapping
itself using the ->callback functionality.

Cc: Dan Williams <djbw@...com>
Cc: Tomasz Figa <t.figa@...sung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@...sung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@...sung.com>
---
 crypto/async_tx/async_memset.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/crypto/async_tx/async_memset.c b/crypto/async_tx/async_memset.c
index a6a667b..cf30bf1 100644
--- a/crypto/async_tx/async_memset.c
+++ b/crypto/async_tx/async_memset.c
@@ -30,6 +30,17 @@
 #include <linux/dma-mapping.h>
 #include <linux/async_tx.h>
 
+static void async_memset_cb(void *dma_async_param)
+{
+	struct dma_async_tx_descriptor *tx = dma_async_param;
+	struct dma_device *dev = tx->chan->device;
+
+	dma_unmap_page(dev->dev, tx->dma_dst, tx->dma_len, DMA_FROM_DEVICE);
+
+	if (tx->orig_callback)
+		tx->orig_callback(tx->orig_callback_param);
+}
+
 /**
  * async_memset - attempt to fill memory with a dma engine.
  * @dest: destination page
@@ -47,10 +58,11 @@ async_memset(struct page *dest, int val, unsigned int offset, size_t len,
 						      &dest, 1, NULL, 0, len);
 	struct dma_device *device = chan ? chan->device : NULL;
 	struct dma_async_tx_descriptor *tx = NULL;
+	dma_addr_t dma_dest;
 
 	if (device && is_dma_fill_aligned(device, offset, 0, len)) {
-		dma_addr_t dma_dest;
-		unsigned long dma_prep_flags = 0;
+		unsigned long dma_prep_flags = DMA_COMPL_SKIP_SRC_UNMAP |
+					       DMA_COMPL_SKIP_DEST_UNMAP;
 
 		if (submit->cb_fn)
 			dma_prep_flags |= DMA_PREP_INTERRUPT;
@@ -68,7 +80,11 @@ async_memset(struct page *dest, int val, unsigned int offset, size_t len,
 
 	if (tx) {
 		pr_debug("%s: (async) len: %zu\n", __func__, len);
-		async_tx_submit(chan, tx, submit);
+
+		tx->dma_dst = dma_dest;
+		tx->dma_len = len;
+
+		__async_tx_submit(chan, tx, async_memset_cb, tx, submit);
 	} else { /* run the memset synchronously */
 		void *dest_buf;
 		pr_debug("%s: (sync) len: %zu\n", __func__, len);
-- 
1.8.0

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