From eec12f66b02c3812252103d5efcb80754b04012c Mon Sep 17 00:00:00 2001 From: Cyrille Pitchen Date: Thu, 26 Jan 2017 17:07:52 +0100 Subject: 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: Cyrille Pitchen Signed-off-by: Herbert Xu --- drivers/crypto/atmel-sha.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 90 insertions(+) (limited to 'drivers/crypto') diff --git a/drivers/crypto/atmel-sha.c b/drivers/crypto/atmel-sha.c index be0d72cf4352..58d9ca8ac0f2 100644 --- a/drivers/crypto/atmel-sha.c +++ b/drivers/crypto/atmel-sha.c @@ -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; -- cgit v1.2.3