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Commit eec12f66 authored by Cyrille Pitchen's avatar Cyrille Pitchen Committed by Herbert Xu
Browse files

crypto: atmel-sha - add atmel_sha_cpu_start() 



This patch adds a simple function to perform data transfer with PIO, hence
handled by the CPU.

Signed-off-by: default avatarCyrille Pitchen <cyrille.pitchen@atmel.com>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent 563c47df

drivers/crypto/atmel-sha.c

+90 −0
Original line number Diff line number Diff line
@@ -64,6 +64,8 @@ 
#define SHA_FLAGS_ERROR		BIT(23)

#define SHA_FLAGS_PAD		BIT(24)

#define SHA_FLAGS_RESTORE	BIT(25)

#define SHA_FLAGS_IDATAR0	BIT(26)

#define SHA_FLAGS_WAIT_DATARDY	BIT(27)



#define SHA_OP_UPDATE	1

#define SHA_OP_FINAL	2
@@ -141,6 +143,7 @@ struct atmel_sha_dev { 
	struct ahash_request	*req;

	bool			is_async;

	atmel_sha_fn_t		resume;

	atmel_sha_fn_t		cpu_transfer_complete;



	struct atmel_sha_dma	dma_lch_in;
@@ -1317,6 +1320,93 @@ static irqreturn_t atmel_sha_irq(int irq, void *dev_id) 
	return IRQ_NONE;

}





/* CPU transfer functions */



static int atmel_sha_cpu_transfer(struct atmel_sha_dev *dd)

{

	struct ahash_request *req = dd->req;

	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);

	const u32 *words = (const u32 *)ctx->buffer;

	size_t i, num_words;

	u32 isr, din, din_inc;



	din_inc = (ctx->flags & SHA_FLAGS_IDATAR0) ? 0 : 1;

	for (;;) {

		/* Write data into the Input Data Registers. */

		num_words = DIV_ROUND_UP(ctx->bufcnt, sizeof(u32));

		for (i = 0, din = 0; i < num_words; ++i, din += din_inc)

			atmel_sha_write(dd, SHA_REG_DIN(din), words[i]);



		ctx->offset += ctx->bufcnt;

		ctx->total -= ctx->bufcnt;



		if (!ctx->total)

			break;



		/*

		 * Prepare next block:

		 * Fill ctx->buffer now with the next data to be written into

		 * IDATARx: it gives time for the SHA hardware to process

		 * the current data so the SHA_INT_DATARDY flag might be set

		 * in SHA_ISR when polling this register at the beginning of

		 * the next loop.

		 */

		ctx->bufcnt = min_t(size_t, ctx->block_size, ctx->total);

		scatterwalk_map_and_copy(ctx->buffer, ctx->sg,

					 ctx->offset, ctx->bufcnt, 0);



		/* Wait for hardware to be ready again. */

		isr = atmel_sha_read(dd, SHA_ISR);

		if (!(isr & SHA_INT_DATARDY)) {

			/* Not ready yet. */

			dd->resume = atmel_sha_cpu_transfer;

			atmel_sha_write(dd, SHA_IER, SHA_INT_DATARDY);

			return -EINPROGRESS;

		}

	}



	if (unlikely(!(ctx->flags & SHA_FLAGS_WAIT_DATARDY)))

		return dd->cpu_transfer_complete(dd);



	return atmel_sha_wait_for_data_ready(dd, dd->cpu_transfer_complete);

}



static int atmel_sha_cpu_start(struct atmel_sha_dev *dd,

			       struct scatterlist *sg,

			       unsigned int len,

			       bool idatar0_only,

			       bool wait_data_ready,

			       atmel_sha_fn_t resume)

{

	struct ahash_request *req = dd->req;

	struct atmel_sha_reqctx *ctx = ahash_request_ctx(req);



	if (!len)

		return resume(dd);



	ctx->flags &= ~(SHA_FLAGS_IDATAR0 | SHA_FLAGS_WAIT_DATARDY);



	if (idatar0_only)

		ctx->flags |= SHA_FLAGS_IDATAR0;



	if (wait_data_ready)

		ctx->flags |= SHA_FLAGS_WAIT_DATARDY;



	ctx->sg = sg;

	ctx->total = len;

	ctx->offset = 0;



	/* Prepare the first block to be written. */

	ctx->bufcnt = min_t(size_t, ctx->block_size, ctx->total);

	scatterwalk_map_and_copy(ctx->buffer, ctx->sg,

				 ctx->offset, ctx->bufcnt, 0);



	dd->cpu_transfer_complete = resume;

	return atmel_sha_cpu_transfer(dd);

}





static void atmel_sha_unregister_algs(struct atmel_sha_dev *dd)

{

	int i;