dmaengine: dmatest: Add alignment parameter

Add parameter "alignment" to allow setting the address alignment
manually. Having the ability to configure address alignment from
user space adds new testing capabilities where different alignments can
be configured for testing without having to modify the dma device
alignment properties.

If configured, the alignment value will override the device alignment
property of the target device.
Signed-off-by: Seraj Alijan <seraj.alijan@sondrel.com>
Signed-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/dmatest.c

@@ -79,6 +79,10 @@ static bool verbose;
 module_param(verbose, bool, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(verbose, "Enable \"success\" result messages (default: off)");
 
+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))");
+
 /**
  * struct dmatest_params - test parameters.
  * @buf_size:		size of the memcpy test buffer
@@ -103,6 +107,7 @@ struct dmatest_params {
 	int		timeout;
 	bool		noverify;
 	bool		norandom;
+	int		alignment;
 };
 
 /**
@@ -526,22 +531,26 @@ static int dmatest_func(void *data)
 	chan = thread->chan;
 	dev = chan->device;
 	if (thread->type == DMA_MEMCPY) {
-		align = dev->copy_align;
+		align = params->alignment < 0 ? dev->copy_align :
+						params->alignment;
 		src_cnt = dst_cnt = 1;
 	} else if (thread->type == DMA_MEMSET) {
-		align = dev->fill_align;
+		align = params->alignment < 0 ? dev->fill_align :
+						params->alignment;
 		src_cnt = dst_cnt = 1;
 		is_memset = true;
 	} else if (thread->type == DMA_XOR) {
 		/* force odd to ensure dst = src */
 		src_cnt = min_odd(params->xor_sources | 1, dev->max_xor);
 		dst_cnt = 1;
-		align = dev->xor_align;
+		align = params->alignment < 0 ? dev->xor_align :
+						params->alignment;
 	} else if (thread->type == DMA_PQ) {
 		/* force odd to ensure dst = src */
 		src_cnt = min_odd(params->pq_sources | 1, dma_maxpq(dev, 0));
 		dst_cnt = 2;
-		align = dev->pq_align;
+		align = params->alignment < 0 ? dev->pq_align :
+						params->alignment;
 
 		pq_coefs = kmalloc(params->pq_sources + 1, GFP_KERNEL);
 		if (!pq_coefs)
@@ -1037,6 +1046,7 @@ static void add_threaded_test(struct dmatest_info *info)
 	params->timeout = timeout;
 	params->noverify = noverify;
 	params->norandom = norandom;
+	params->alignment = alignment;
 
 	request_channels(info, DMA_MEMCPY);
 	request_channels(info, DMA_MEMSET);