dmaengine: dmatest: Add transfer_size parameter

Existing transfer size "len" is either generated randomly or set to the
size of test_buf_size. In some cases we need to explicitly specify a
transfer size that is different from the buffer size and non aligned to
test the target device's ability to handle unaligned transfers.

This patch adds optional parameter "transfer_size" to allow setting
explicit transfer size for dma transfers.

Signed-off-by: Seraj Alijan <seraj.alijan@sondrel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

1 files changed, 22 insertions, 6 deletions

diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index 6302ebef2938..2eea4ef72915 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -83,6 +83,10 @@ static int alignment = -1;
 module_param(alignment, int, 0644);
 MODULE_PARM_DESC(alignment, "Custom data address alignment taken as 2^(alignment) (default: not used (-1))");
 
+static unsigned int transfer_size;
+module_param(transfer_size, uint, 0644);
+MODULE_PARM_DESC(transfer_size, "Optional custom transfer size in bytes (default: not used (0))");
+
 /**
  * struct dmatest_params - test parameters.
  * @buf_size:           size of the memcpy test buffer
@@ -108,6 +112,7 @@ struct dmatest_params {
         bool            noverify;
         bool            norandom;
         int             alignment;
+        unsigned int    transfer_size;
 };
 
 /**
@@ -643,15 +648,25 @@ static int dmatest_func(void *data)
 
                 total_tests++;
 
-                if (params->norandom)
+                if (params->transfer_size) {
+                        if (params->transfer_size >= params->buf_size) {
+                                pr_err("%u-byte transfer size must be lower than %u-buffer size\n",
+                                       params->transfer_size, params->buf_size);
+                                break;
+                        }
+                        len = params->transfer_size;
+                } else if (params->norandom) {
                         len = params->buf_size;
-                else
+                } else {
                         len = dmatest_random() % params->buf_size + 1;
+                }
 
-                len = (len >> align) << align;
-                if (!len)
-                        len = 1 << align;
-
+                /* Do not alter transfer size explicitly defined by user */
+                if (!params->transfer_size) {
+                        len = (len >> align) << align;
+                        if (!len)
+                                len = 1 << align;
+                }
                 total_len += len;
 
                 if (params->norandom) {
@@ -1047,6 +1062,7 @@ static void add_threaded_test(struct dmatest_info *info)
         params->noverify = noverify;
         params->norandom = norandom;
         params->alignment = alignment;
+        params->transfer_size = transfer_size;
 
         request_channels(info, DMA_MEMCPY);
         request_channels(info, DMA_MEMSET);