dmatest: Use custom map/unmap for destination buffer

The dmatest driver should use DMA_BIDIRECTIONAL on the destination buffer
to ensure that the poison values are written to RAM and not just written
to cache and discarded.

Acked-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 31 insertions, 4 deletions

diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index 3603f1ea5b28..732fa1ec36ab 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -217,6 +217,10 @@ static int dmatest_func(void *data)
         chan = thread->chan;
 
         while (!kthread_should_stop()) {
+                struct dma_device *dev = chan->device;
+                struct dma_async_tx_descriptor *tx;
+                dma_addr_t dma_src, dma_dest;
+
                 total_tests++;
 
                 len = dmatest_random() % test_buf_size + 1;
@@ -226,10 +230,30 @@ static int dmatest_func(void *data)
                 dmatest_init_srcbuf(thread->srcbuf, src_off, len);
                 dmatest_init_dstbuf(thread->dstbuf, dst_off, len);
 
-                cookie = dma_async_memcpy_buf_to_buf(chan,
-                                thread->dstbuf + dst_off,
-                                thread->srcbuf + src_off,
-                                len);
+                dma_src = dma_map_single(dev->dev, thread->srcbuf + src_off,
+                                len, DMA_TO_DEVICE);
+                /* map with DMA_BIDIRECTIONAL to force writeback/invalidate */
+                dma_dest = dma_map_single(dev->dev, thread->dstbuf,
+                                test_buf_size, DMA_BIDIRECTIONAL);
+
+                tx = dev->device_prep_dma_memcpy(chan, dma_dest + dst_off,
+                                dma_src, len,
+                                DMA_CTRL_ACK | DMA_COMPL_SKIP_DEST_UNMAP);
+                if (!tx) {
+                        dma_unmap_single(dev->dev, dma_src, len, DMA_TO_DEVICE);
+                        dma_unmap_single(dev->dev, dma_dest,
+                                        test_buf_size, DMA_BIDIRECTIONAL);
+                        pr_warning("%s: #%u: prep error with src_off=0x%x "
+                                        "dst_off=0x%x len=0x%x\n",
+                                        thread_name, total_tests - 1,
+                                        src_off, dst_off, len);
+                        msleep(100);
+                        failed_tests++;
+                        continue;
+                }
+                tx->callback = NULL;
+                cookie = tx->tx_submit(tx);
+
                 if (dma_submit_error(cookie)) {
                         pr_warning("%s: #%u: submit error %d with src_off=0x%x "
                                         "dst_off=0x%x len=0x%x\n",
@@ -253,6 +277,9 @@ static int dmatest_func(void *data)
                         failed_tests++;
                         continue;
                 }
+                /* Unmap by myself (see DMA_COMPL_SKIP_DEST_UNMAP above) */
+                dma_unmap_single(dev->dev, dma_dest,
+                                test_buf_size, DMA_BIDIRECTIONAL);
 
                 error_count = 0;