dma: mv_xor: Use dmaengine_unmap_data for the self-tests

The driver-specific unmap code was removed in:

  commit 54f8d501
  Author: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
  Date:   Fri Oct 18 19:35:32 2013 +0200

      dmaengine: remove DMA unmap from drivers

which had the side-effect of not unmapping the self-test mappings.
Fix this by using dmaengine_unmap_data in the self-test routines.

In addition, since dmaengine_unmap() assumes that all mappings were created
with dma_map_page, this commit changes the single mapping to a page mapping
to avoid an incorrect unmapping of the memcpy self-test.

The allocation could be changed to be alloc_page(), but sticking to kmalloc
results in a less intrusive patch. The size of the test buffer is increased,
since dma_map_page() seem to fail when the source and destination pages are
the same page.
Signed-off-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/dma/mv_xor.c

@@ -781,7 +781,6 @@ static void mv_xor_issue_pending(struct dma_chan *chan)
 /*
  * Perform a transaction to verify the HW works.
  */
-#define MV_XOR_TEST_SIZE 2000
 
 static int mv_xor_memcpy_self_test(struct mv_xor_chan *mv_chan)
 {
@@ -791,20 +790,21 @@ static int mv_xor_memcpy_self_test(struct mv_xor_chan *mv_chan)
 	struct dma_chan *dma_chan;
 	dma_cookie_t cookie;
 	struct dma_async_tx_descriptor *tx;
+	struct dmaengine_unmap_data *unmap;
 	int err = 0;
 
-	src = kmalloc(sizeof(u8) * MV_XOR_TEST_SIZE, GFP_KERNEL);
+	src = kmalloc(sizeof(u8) * PAGE_SIZE, GFP_KERNEL);
 	if (!src)
 		return -ENOMEM;
 
-	dest = kzalloc(sizeof(u8) * MV_XOR_TEST_SIZE, GFP_KERNEL);
+	dest = kzalloc(sizeof(u8) * PAGE_SIZE, GFP_KERNEL);
 	if (!dest) {
 		kfree(src);
 		return -ENOMEM;
 	}
 
 	/* Fill in src buffer */
-	for (i = 0; i < MV_XOR_TEST_SIZE; i++)
+	for (i = 0; i < PAGE_SIZE; i++)
 		((u8 *) src)[i] = (u8)i;
 
 	dma_chan = &mv_chan->dmachan;
@@ -813,14 +813,26 @@ static int mv_xor_memcpy_self_test(struct mv_xor_chan *mv_chan)
 		goto out;
 	}
 
-	dest_dma = dma_map_single(dma_chan->device->dev, dest,
-				  MV_XOR_TEST_SIZE, DMA_FROM_DEVICE);
+	unmap = dmaengine_get_unmap_data(dma_chan->device->dev, 2, GFP_KERNEL);
+	if (!unmap) {
+		err = -ENOMEM;
+		goto free_resources;
+	}
+
+	src_dma = dma_map_page(dma_chan->device->dev, virt_to_page(src), 0,
+				 PAGE_SIZE, DMA_TO_DEVICE);
+	unmap->to_cnt = 1;
+	unmap->addr[0] = src_dma;
 
-	src_dma = dma_map_single(dma_chan->device->dev, src,
-				 MV_XOR_TEST_SIZE, DMA_TO_DEVICE);
+	dest_dma = dma_map_page(dma_chan->device->dev, virt_to_page(dest), 0,
+				  PAGE_SIZE, DMA_FROM_DEVICE);
+	unmap->from_cnt = 1;
+	unmap->addr[1] = dest_dma;
+
+	unmap->len = PAGE_SIZE;
 
 	tx = mv_xor_prep_dma_memcpy(dma_chan, dest_dma, src_dma,
-				    MV_XOR_TEST_SIZE, 0);
+				    PAGE_SIZE, 0);
 	cookie = mv_xor_tx_submit(tx);
 	mv_xor_issue_pending(dma_chan);
 	async_tx_ack(tx);
@@ -835,8 +847,8 @@ static int mv_xor_memcpy_self_test(struct mv_xor_chan *mv_chan)
 	}
 
 	dma_sync_single_for_cpu(dma_chan->device->dev, dest_dma,
-				MV_XOR_TEST_SIZE, DMA_FROM_DEVICE);
-	if (memcmp(src, dest, MV_XOR_TEST_SIZE)) {
+				PAGE_SIZE, DMA_FROM_DEVICE);
+	if (memcmp(src, dest, PAGE_SIZE)) {
 		dev_err(dma_chan->device->dev,
 			"Self-test copy failed compare, disabling\n");
 		err = -ENODEV;
@@ -844,6 +856,7 @@ static int mv_xor_memcpy_self_test(struct mv_xor_chan *mv_chan)
 	}
 
 free_resources:
+	dmaengine_unmap_put(unmap);
 	mv_xor_free_chan_resources(dma_chan);
 out:
 	kfree(src);
@@ -861,13 +874,15 @@ mv_xor_xor_self_test(struct mv_xor_chan *mv_chan)
 	dma_addr_t dma_srcs[MV_XOR_NUM_SRC_TEST];
 	dma_addr_t dest_dma;
 	struct dma_async_tx_descriptor *tx;
+	struct dmaengine_unmap_data *unmap;
 	struct dma_chan *dma_chan;
 	dma_cookie_t cookie;
 	u8 cmp_byte = 0;
 	u32 cmp_word;
 	int err = 0;
+	int src_count = MV_XOR_NUM_SRC_TEST;
 
-	for (src_idx = 0; src_idx < MV_XOR_NUM_SRC_TEST; src_idx++) {
+	for (src_idx = 0; src_idx < src_count; src_idx++) {
 		xor_srcs[src_idx] = alloc_page(GFP_KERNEL);
 		if (!xor_srcs[src_idx]) {
 			while (src_idx--)
@@ -884,13 +899,13 @@ mv_xor_xor_self_test(struct mv_xor_chan *mv_chan)
 	}
 
 	/* Fill in src buffers */
-	for (src_idx = 0; src_idx < MV_XOR_NUM_SRC_TEST; src_idx++) {
+	for (src_idx = 0; src_idx < src_count; src_idx++) {
 		u8 *ptr = page_address(xor_srcs[src_idx]);
 		for (i = 0; i < PAGE_SIZE; i++)
 			ptr[i] = (1 << src_idx);
 	}
 
-	for (src_idx = 0; src_idx < MV_XOR_NUM_SRC_TEST; src_idx++)
+	for (src_idx = 0; src_idx < src_count; src_idx++)
 		cmp_byte ^= (u8) (1 << src_idx);
 
 	cmp_word = (cmp_byte << 24) | (cmp_byte << 16) |
@@ -904,16 +919,29 @@ mv_xor_xor_self_test(struct mv_xor_chan *mv_chan)
 		goto out;
 	}
 
+	unmap = dmaengine_get_unmap_data(dma_chan->device->dev, src_count + 1,
+					 GFP_KERNEL);
+	if (!unmap) {
+		err = -ENOMEM;
+		goto free_resources;
+	}
+
 	/* test xor */
-	dest_dma = dma_map_page(dma_chan->device->dev, dest, 0, PAGE_SIZE,
-				DMA_FROM_DEVICE);
+	for (i = 0; i < src_count; i++) {
+		unmap->addr[i] = dma_map_page(dma_chan->device->dev, xor_srcs[i],
+					      0, PAGE_SIZE, DMA_TO_DEVICE);
+		dma_srcs[i] = unmap->addr[i];
+		unmap->to_cnt++;
+	}
 
-	for (i = 0; i < MV_XOR_NUM_SRC_TEST; i++)
-		dma_srcs[i] = dma_map_page(dma_chan->device->dev, xor_srcs[i],
-					   0, PAGE_SIZE, DMA_TO_DEVICE);
+	unmap->addr[src_count] = dma_map_page(dma_chan->device->dev, dest, 0, PAGE_SIZE,
+				      DMA_FROM_DEVICE);
+	dest_dma = unmap->addr[src_count];
+	unmap->from_cnt = 1;
+	unmap->len = PAGE_SIZE;
 
 	tx = mv_xor_prep_dma_xor(dma_chan, dest_dma, dma_srcs,
-				 MV_XOR_NUM_SRC_TEST, PAGE_SIZE, 0);
+				 src_count, PAGE_SIZE, 0);
 
 	cookie = mv_xor_tx_submit(tx);
 	mv_xor_issue_pending(dma_chan);
@@ -942,9 +970,10 @@ mv_xor_xor_self_test(struct mv_xor_chan *mv_chan)
 	}
 
 free_resources:
+	dmaengine_unmap_put(unmap);
 	mv_xor_free_chan_resources(dma_chan);
 out:
-	src_idx = MV_XOR_NUM_SRC_TEST;
+	src_idx = src_count;
 	while (src_idx--)
 		__free_page(xor_srcs[src_idx]);
 	__free_page(dest);