diff options
Diffstat (limited to 'drivers/crypto')
| -rw-r--r-- | drivers/crypto/atmel-aes.c | 117 |
1 files changed, 115 insertions, 2 deletions
diff --git a/drivers/crypto/atmel-aes.c b/drivers/crypto/atmel-aes.c index 5f6dc48616c0..a34919f6b7d7 100644 --- a/drivers/crypto/atmel-aes.c +++ b/drivers/crypto/atmel-aes.c @@ -82,6 +82,7 @@ struct atmel_aes_caps { bool has_dualbuff; bool has_cfb64; + bool has_ctr32; u32 max_burst_size; }; @@ -103,6 +104,15 @@ struct atmel_aes_ctx { struct atmel_aes_base_ctx base; }; +struct atmel_aes_ctr_ctx { + struct atmel_aes_base_ctx base; + + u32 iv[AES_BLOCK_SIZE / sizeof(u32)]; + size_t offset; + struct scatterlist src[2]; + struct scatterlist dst[2]; +}; + struct atmel_aes_reqctx { unsigned long mode; }; @@ -762,6 +772,96 @@ static int atmel_aes_start(struct atmel_aes_dev *dd) atmel_aes_transfer_complete); } +static inline struct atmel_aes_ctr_ctx * +atmel_aes_ctr_ctx_cast(struct atmel_aes_base_ctx *ctx) +{ + return container_of(ctx, struct atmel_aes_ctr_ctx, base); +} + +static int atmel_aes_ctr_transfer(struct atmel_aes_dev *dd) +{ + struct atmel_aes_ctr_ctx *ctx = atmel_aes_ctr_ctx_cast(dd->ctx); + struct ablkcipher_request *req = ablkcipher_request_cast(dd->areq); + struct scatterlist *src, *dst; + u32 ctr, blocks; + size_t datalen; + bool use_dma, fragmented = false; + + /* Check for transfer completion. */ + ctx->offset += dd->total; + if (ctx->offset >= req->nbytes) + return atmel_aes_transfer_complete(dd); + + /* Compute data length. */ + datalen = req->nbytes - ctx->offset; + blocks = DIV_ROUND_UP(datalen, AES_BLOCK_SIZE); + ctr = be32_to_cpu(ctx->iv[3]); + if (dd->caps.has_ctr32) { + /* Check 32bit counter overflow. */ + u32 start = ctr; + u32 end = start + blocks - 1; + + if (end < start) { + ctr |= 0xffffffff; + datalen = AES_BLOCK_SIZE * -start; + fragmented = true; + } + } else { + /* Check 16bit counter overflow. */ + u16 start = ctr & 0xffff; + u16 end = start + (u16)blocks - 1; + + if (blocks >> 16 || end < start) { + ctr |= 0xffff; + datalen = AES_BLOCK_SIZE * (0x10000-start); + fragmented = true; + } + } + use_dma = (datalen >= ATMEL_AES_DMA_THRESHOLD); + + /* Jump to offset. */ + src = scatterwalk_ffwd(ctx->src, req->src, ctx->offset); + dst = ((req->src == req->dst) ? src : + scatterwalk_ffwd(ctx->dst, req->dst, ctx->offset)); + + /* Configure hardware. */ + atmel_aes_write_ctrl(dd, use_dma, ctx->iv); + if (unlikely(fragmented)) { + /* + * Increment the counter manually to cope with the hardware + * counter overflow. + */ + ctx->iv[3] = cpu_to_be32(ctr); + crypto_inc((u8 *)ctx->iv, AES_BLOCK_SIZE); + } + + if (use_dma) + return atmel_aes_dma_start(dd, src, dst, datalen, + atmel_aes_ctr_transfer); + + return atmel_aes_cpu_start(dd, src, dst, datalen, + atmel_aes_ctr_transfer); +} + +static int atmel_aes_ctr_start(struct atmel_aes_dev *dd) +{ + struct atmel_aes_ctr_ctx *ctx = atmel_aes_ctr_ctx_cast(dd->ctx); + struct ablkcipher_request *req = ablkcipher_request_cast(dd->areq); + struct atmel_aes_reqctx *rctx = ablkcipher_request_ctx(req); + int err; + + atmel_aes_set_mode(dd, rctx); + + err = atmel_aes_hw_init(dd); + if (err) + return atmel_aes_complete(dd, err); + + memcpy(ctx->iv, req->info, AES_BLOCK_SIZE); + ctx->offset = 0; + dd->total = 0; + return atmel_aes_ctr_transfer(dd); +} + static int atmel_aes_crypt(struct ablkcipher_request *req, unsigned long mode) { struct atmel_aes_base_ctx *ctx; @@ -919,6 +1019,16 @@ static int atmel_aes_cra_init(struct crypto_tfm *tfm) return 0; } +static int atmel_aes_ctr_cra_init(struct crypto_tfm *tfm) +{ + struct atmel_aes_ctx *ctx = crypto_tfm_ctx(tfm); + + tfm->crt_ablkcipher.reqsize = sizeof(struct atmel_aes_reqctx); + ctx->base.start = atmel_aes_ctr_start; + + return 0; +} + static void atmel_aes_cra_exit(struct crypto_tfm *tfm) { } @@ -1076,11 +1186,11 @@ static struct crypto_alg aes_algs[] = { .cra_priority = ATMEL_AES_PRIORITY, .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC, .cra_blocksize = 1, - .cra_ctxsize = sizeof(struct atmel_aes_ctx), + .cra_ctxsize = sizeof(struct atmel_aes_ctr_ctx), .cra_alignmask = 0xf, .cra_type = &crypto_ablkcipher_type, .cra_module = THIS_MODULE, - .cra_init = atmel_aes_cra_init, + .cra_init = atmel_aes_ctr_cra_init, .cra_exit = atmel_aes_cra_exit, .cra_u.ablkcipher = { .min_keysize = AES_MIN_KEY_SIZE, @@ -1262,6 +1372,7 @@ static void atmel_aes_get_cap(struct atmel_aes_dev *dd) { dd->caps.has_dualbuff = 0; dd->caps.has_cfb64 = 0; + dd->caps.has_ctr32 = 0; dd->caps.max_burst_size = 1; /* keep only major version number */ @@ -1269,11 +1380,13 @@ static void atmel_aes_get_cap(struct atmel_aes_dev *dd) case 0x500: dd->caps.has_dualbuff = 1; dd->caps.has_cfb64 = 1; + dd->caps.has_ctr32 = 1; dd->caps.max_burst_size = 4; break; case 0x200: dd->caps.has_dualbuff = 1; dd->caps.has_cfb64 = 1; + dd->caps.has_ctr32 = 1; dd->caps.max_burst_size = 4; break; case 0x130: |