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Commit 69303cf0 authored by Cyrille Pitchen's avatar Cyrille Pitchen Committed by Herbert Xu
Browse files

crypto: atmel-sha - add simple DMA transfers 



This patch adds a simple function to perform data transfer with the DMA
controller.

Signed-off-by: default avatarCyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent eec12f66

drivers/crypto/atmel-sha.c

+116 −0
Original line number Diff line number Diff line
@@ -123,6 +123,9 @@ struct atmel_sha_ctx { 
struct atmel_sha_dma {

	struct dma_chan			*chan;

	struct dma_slave_config dma_conf;

	struct scatterlist	*sg;

	int			nents;

	unsigned int		last_sg_length;

};



struct atmel_sha_dev {
@@ -1321,6 +1324,119 @@ static irqreturn_t atmel_sha_irq(int irq, void *dev_id) 
}





/* DMA transfer functions */



static bool atmel_sha_dma_check_aligned(struct atmel_sha_dev *dd,

					struct scatterlist *sg,

					size_t len)

{

	struct atmel_sha_dma *dma = &dd->dma_lch_in;

	struct ahash_request *req = dd->req;

	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

	size_t bs = ctx->block_size;

	int nents;



	for (nents = 0; sg; sg = sg_next(sg), ++nents) {

		if (!IS_ALIGNED(sg->offset, sizeof(u32)))

			return false;



		/*

		 * This is the last sg, the only one that is allowed to

		 * have an unaligned length.

		 */

		if (len <= sg->length) {

			dma->nents = nents + 1;

			dma->last_sg_length = sg->length;

			sg->length = ALIGN(len, sizeof(u32));

			return true;

		}



		/* All other sg lengths MUST be aligned to the block size. */

		if (!IS_ALIGNED(sg->length, bs))

			return false;



		len -= sg->length;

	}



	return false;

}



static void atmel_sha_dma_callback2(void *data)

{

	struct atmel_sha_dev *dd = data;

	struct atmel_sha_dma *dma = &dd->dma_lch_in;

	struct scatterlist *sg;

	int nents;



	dmaengine_terminate_all(dma->chan);

	dma_unmap_sg(dd->dev, dma->sg, dma->nents, DMA_TO_DEVICE);



	sg = dma->sg;

	for (nents = 0; nents < dma->nents - 1; ++nents)

		sg = sg_next(sg);

	sg->length = dma->last_sg_length;



	dd->is_async = true;

	(void)atmel_sha_wait_for_data_ready(dd, dd->resume);

}



static int atmel_sha_dma_start(struct atmel_sha_dev *dd,

			       struct scatterlist *src,

			       size_t len,

			       atmel_sha_fn_t resume)

{

	struct atmel_sha_dma *dma = &dd->dma_lch_in;

	struct dma_slave_config *config = &dma->dma_conf;

	struct dma_chan *chan = dma->chan;

	struct dma_async_tx_descriptor *desc;

	dma_cookie_t cookie;

	unsigned int sg_len;

	int err;



	dd->resume = resume;



	/*

	 * dma->nents has already been initialized by

	 * atmel_sha_dma_check_aligned().

	 */

	dma->sg = src;

	sg_len = dma_map_sg(dd->dev, dma->sg, dma->nents, DMA_TO_DEVICE);

	if (!sg_len) {

		err = -ENOMEM;

		goto exit;

	}



	config->src_maxburst = 16;

	config->dst_maxburst = 16;

	err = dmaengine_slave_config(chan, config);

	if (err)

		goto unmap_sg;



	desc = dmaengine_prep_slave_sg(chan, dma->sg, sg_len, DMA_MEM_TO_DEV,

				       DMA_PREP_INTERRUPT | DMA_CTRL_ACK);

	if (!desc) {

		err = -ENOMEM;

		goto unmap_sg;

	}



	desc->callback = atmel_sha_dma_callback2;

	desc->callback_param = dd;

	cookie = dmaengine_submit(desc);

	err = dma_submit_error(cookie);

	if (err)

		goto unmap_sg;



	dma_async_issue_pending(chan);



	return -EINPROGRESS;



unmap_sg:

	dma_unmap_sg(dd->dev, dma->sg, dma->nents, DMA_TO_DEVICE);

exit:

	return atmel_sha_complete(dd, err);

}





/* CPU transfer functions */



static int atmel_sha_cpu_transfer(struct atmel_sha_dev *dd)