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crypto: atmel-sha - add simple DMA transfers 

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

Signed-off-by: Cyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Cyrille Pitchen 2017-01-26 17:07:53 +01:00 committed by Herbert Xu
parent eec12f66b0
commit 69303cf0f1
1 changed files with 116 additions and 0 deletions
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116
drivers/crypto/atmel-sha.c
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@ -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)