From: Kim Phillips Subject: Re: [PATCH] picoxcell_crypto: add support for the picoxcell crypto engines Date: Thu, 10 Feb 2011 22:09:16 -0600 Message-ID: <20110210220916.aac2b545.kim.phillips@freescale.com> References: <1297180576-11581-1-git-send-email-jamie@jamieiles.com> Mime-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Cc: , , Herbert Xu To: Jamie Iles Return-path: Received: from va3ehsobe006.messaging.microsoft.com ([216.32.180.16]:2011 "EHLO VA3EHSOBE009.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1750840Ab1BKEJY (ORCPT ); Thu, 10 Feb 2011 23:09:24 -0500 In-Reply-To: <1297180576-11581-1-git-send-email-jamie@jamieiles.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: On Tue, 8 Feb 2011 15:56:16 +0000 Jamie Iles wrote: > Picochip picoXcell devices have two crypto engines, one targeted > at IPSEC offload and the other at WCDMA layer 2 ciphering. > > Cc: Herbert Xu > Signed-off-by: Jamie Iles > --- nice driver ;). Have a couple of comments though. > + help > + This option enables support for the hardware offload engines in the > + Picochip picoXcell SoC devices. Select this for IPSEC ESP offload > + and for 3gpp Layer 2 ciphering support. it'd be nice to mention what name the module will have. > +#define SPACC_CRYPTO_AES_MAX_KEY_LEN 32 > +#define SPACC_CRYPTO_AES_IV_LEN 16 > +#define SPACC_CRYPTO_DES_IV_LEN 8 these are identical to algorithm-generic symbolic constants AES_MAX_KEY_SIZE, [AD]ES_BLOCK_SIZE - why not use them instead? > +struct spacc_generic_ctx; this declaration isn't used prior to its definition, so it's not needed. > +/* DDT format. This must match the hardware DDT format exactly. */ > +struct spacc_ddt { > + u32 p, len; type-consistency: p should be a dma_addr_t > + /* AEAD specifc bits. */ specific > +static inline struct spacc_ablk_ctx * > +to_spacc_ablk_ctx(struct spacc_generic_ctx *ctx) > +{ > + return ctx ? container_of(ctx, struct spacc_ablk_ctx, generic) : NULL; > +} > + > +static inline struct spacc_aead_ctx * > +to_spacc_aead_ctx(struct spacc_generic_ctx *ctx) > +{ > + return ctx ? container_of(ctx, struct spacc_aead_ctx, generic) : NULL; > +} these aren't being used anywhere. > +static inline struct spacc_alg *to_spacc_alg(struct crypto_alg *alg); define it here - forward declarations should only be necessary when dealing with circular dependencies. > +/* > + * Take a crypto request and scatterlists for the data and turn them into DDTs > + * for passing to the crypto engines. This also DMA maps the data so that the > + * crypto engines can DMA to/from them. > + */ > +static struct spacc_ddt *spacc_sg_to_ddt(struct spacc_engine *engine, > + struct scatterlist *payload, > + unsigned nbytes, > + enum dma_data_direction dir, > + dma_addr_t *ddt_phys) > +{ > + unsigned nents, mapped_ents; > + struct scatterlist *cur; > + struct spacc_ddt *ddt; > + int i; > + > + nents = sg_count(payload, nbytes); > + mapped_ents = dma_map_sg(engine->dev, payload, nents, dir); > + > + if (mapped_ents + 1 > MAX_DDT_LEN) { > + dma_unmap_sg(engine->dev, payload, nents, dir); > + return NULL; > + } > + > + ddt = dma_pool_alloc(engine->req_pool, GFP_ATOMIC, ddt_phys); > + if (ddt) { > + for_each_sg(payload, cur, mapped_ents, i) { > + ddt[i].p = sg_dma_address(cur); > + ddt[i].len = sg_dma_len(cur); > + } > + > + ddt[mapped_ents].p = 0; > + ddt[mapped_ents].len = 0; > + } else { > + dma_unmap_sg(engine->dev, payload, nents, dir); > + ddt = NULL; > + } > + > + return ddt; > +} easier to read would be: if (mapped_ents + 1 > MAX_DDT_LEN) goto out; ddt = dma_pool_alloc(engine->req_pool, GFP_ATOMIC, ddt_phys); if (!ddt) goto out; for_each_sg(payload, cur, mapped_ents, i) { ddt[i].p = sg_dma_address(cur); ddt[i].len = sg_dma_len(cur); } ddt[mapped_ents].p = 0; ddt[mapped_ents].len = 0; return ddt; out: dma_unmap_sg(engine->dev, payload, nents, dir); return NULL; } even more so by moving ddt_set() above it, and then using ddt_set() to assign the p, len pairs. > +static inline void ddt_set(struct spacc_ddt *ddt, unsigned long phys, phys should be dma_addr_t > +static int spacc_aead_make_ddts(struct spacc_req *req, u8 *giv) > +{ > + struct aead_request *areq = container_of(req->req, struct aead_request, > + base); > + struct spacc_alg *alg = to_spacc_alg(req->req->tfm->__crt_alg); > + struct spacc_engine *engine = req->engine; > + struct spacc_ddt *src_ddt, *dst_ddt; > + unsigned ivsize = alg->alg.cra_aead.ivsize; no need to go through all those hoops to get to the ivsize - use helper fns crypto_aead_reqtfm() and crypto_aead_ivsize(), as is done at the callsite, or just pass it in from there. > +static int spacc_aead_des_setkey(struct crypto_aead *aead, const u8 *key, > + unsigned int len) > +{ > + struct crypto_tfm *tfm = crypto_aead_tfm(aead); > + struct spacc_aead_ctx *ctx = crypto_tfm_ctx(tfm); > + int err = 0; > + u32 tmp[DES_EXPKEY_WORDS]; > + > + err = des_ekey(tmp, key); > + if (unlikely(!err) && might want to change the name of the variable err here to something like ret or is_weak so as to not mislead the reader. > + (crypto_aead_get_flags(aead)) & CRYPTO_TFM_REQ_WEAK_KEY) { > + tfm->crt_flags |= CRYPTO_TFM_RES_WEAK_KEY; > + return -EINVAL; > + } > + err = 0; > + > + memcpy(ctx->cipher_key, key, len); > + ctx->cipher_key_len = len; > + > + return err; actually, it doesn't look like this fn needs a return variable at all. > +/* Set the key for the AES block cipher component of the AEAD transform. */ > +static int spacc_aead_aes_setkey(struct crypto_aead *aead, const u8 *key, > + unsigned int len) > +{ > + struct crypto_tfm *tfm = crypto_aead_tfm(aead); > + struct spacc_aead_ctx *ctx = crypto_tfm_ctx(tfm); > + int err; > + > + /* > + * IPSec engine only supports 128 and 256 bit AES keys. If we get a > + * request for any other size (192 bits) then we need to do a software > + * fallback. > + */ > + if (!(16 == len || 32 == len)) { if (len != AES_KEYSIZE_128 && len != AES_KEYSIZE_256) > + /* > + * Set the fallback transform to use the same request flags as > + * the hardware transform. > + */ > + ctx->sw_cipher->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK; > + ctx->sw_cipher->base.crt_flags |= > + (tfm->crt_flags & CRYPTO_TFM_REQ_MASK); parens not needed. > + err = crypto_aead_setkey(ctx->sw_cipher, key, len); > + } else { > + memcpy(ctx->cipher_key, key, len); > + ctx->cipher_key_len = len; > + err = 0; > + } > + > + return err; return crypto_aead_setkey(ctx->sw_cipher, key, len); } memcpy(ctx->cipher_key, key, len); ctx->cipher_key_len = len; return 0; > +static int spacc_aead_setkey(struct crypto_aead *tfm, const u8 *key, > + unsigned int keylen) > +{ > + struct spacc_aead_ctx *ctx = crypto_aead_ctx(tfm); > + struct spacc_alg *alg = to_spacc_alg(tfm->base.__crt_alg); > + struct rtattr *rta = (void *)key; > + struct crypto_authenc_key_param *param; > + unsigned int authkeylen, enckeylen; > + int err = -EINVAL; > + > + if (!RTA_OK(rta, keylen)) > + goto badkey; > + > + if (rta->rta_type != CRYPTO_AUTHENC_KEYA_PARAM) > + goto badkey; > + > + if (RTA_PAYLOAD(rta) < sizeof(*param)) > + goto badkey; I'm not sure, but it should be safe to remove the above three checks - they cause a false badkey failure if the keys aren't within an rtattr struct, which, e.g., something like testmgr.c wouldn't do. > + param = RTA_DATA(rta); > + enckeylen = be32_to_cpu(param->enckeylen); > + > + key += RTA_ALIGN(rta->rta_len); > + keylen -= RTA_ALIGN(rta->rta_len); actually, I doubt crypto drivers should be including rtnetlink.h at all...but it's probably ok for now - talitos still does :) > + if ((spacc_alg->ctrl_default & SPACC_CRYPTO_ALG_MASK) == > + SPA_CTRL_CIPH_ALG_AES && > + !(16 == ctx->cipher_key_len || 32 == ctx->cipher_key_len)) as above, please use symbolic equivalents > +static void spacc_aead_complete(struct spacc_req *req) > +{ > + spacc_aead_free_ddts(req); > + > + if (req->req->complete) > + req->req->complete(req->req, req->result); when is there not a completion function? > + /* Set the source and destination DDT pointers. */ > + writel((u32)req->src_addr, engine->regs + SPA_SRC_PTR_REG_OFFSET); > + writel((u32)req->dst_addr, engine->regs + SPA_DST_PTR_REG_OFFSET); cast necessary? > + ctrl = spacc_alg->ctrl_default; > + ctrl |= ((req->ctx_id << SPA_CTRL_CTX_IDX) | > + (1 << SPA_CTRL_ICV_APPEND) | > + (req->is_encrypt ? (1 << SPA_CTRL_ENCRYPT_IDX) : 0) | > + (req->is_encrypt ? (1 << SPA_CTRL_AAD_COPY) : 0)); > + if (!req->is_encrypt) > + ctrl |= (1 << SPA_CTRL_KEY_EXP); ctrl = spacc_alg->ctrl_default | (req->ctx_id << SPA_CTRL_CTX_IDX) | (1 << SPA_CTRL_ICV_APPEND); if (req->is_encrypt) ctrl |= (1 << SPA_CTRL_ENCRYPT_IDX) | (1 << SPA_CTRL_AAD_COPY); else ctrl |= (1 << SPA_CTRL_KEY_EXP); > +static int spacc_des_setkey(struct crypto_ablkcipher *cipher, const u8 *key, > + unsigned int len) > +{ > + struct crypto_tfm *tfm = crypto_ablkcipher_tfm(cipher); > + struct spacc_ablk_ctx *ctx = crypto_tfm_ctx(tfm); > + int err; > + u32 tmp[DES_EXPKEY_WORDS]; > + > + if (len > SPACC_CRYPTO_AES_MAX_KEY_LEN) { AES left overs in a DES setkey > +static int spacc_aes_setkey(struct crypto_ablkcipher *cipher, const u8 *key, > + unsigned int len) > +{ > + struct crypto_tfm *tfm = crypto_ablkcipher_tfm(cipher); > + struct spacc_ablk_ctx *ctx = crypto_tfm_ctx(tfm); > + int err = 0; > + > + if (len > SPACC_CRYPTO_AES_MAX_KEY_LEN) { > + crypto_ablkcipher_set_flags(cipher, CRYPTO_TFM_RES_BAD_KEY_LEN); > + return -EINVAL; > + } > + > + /* > + * IPSec engine only supports 128 and 256 bit AES keys. If we get a > + * request for any other size (192 bits) then we need to do a software > + * fallback. > + */ > + if (!(16 == len || 32 == len) && ctx->sw_cipher) { symbolic constants > + /* > + * Set the fallback transform to use the same request flags as > + * the hardware transform. > + */ > + ctx->sw_cipher->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK; > + ctx->sw_cipher->base.crt_flags |= > + (cipher->base.crt_flags & CRYPTO_TFM_REQ_MASK); parens not necessary > +static int spacc_ablk_need_fallback(struct spacc_req *req) > +{ > + struct spacc_ablk_ctx *ctx; > + struct crypto_tfm *tfm = req->req->tfm; > + struct crypto_alg *alg = req->req->tfm->__crt_alg; > + struct spacc_alg *spacc_alg = to_spacc_alg(alg); > + > + ctx = crypto_tfm_ctx(tfm); > + > + return (spacc_alg->ctrl_default & SPACC_CRYPTO_ALG_MASK) == > + SPA_CTRL_CIPH_ALG_AES && > + !(16 == ctx->key_len || 32 == ctx->key_len); symbolic constants > +static ssize_t spacc_stat_irq_thresh_store(struct device *dev, > + struct device_attribute *attr, > + const char *buf, size_t len) > +{ > + struct spacc_engine *engine = spacc_dev_to_engine(dev); > + unsigned thresh = simple_strtoul(buf, NULL, 0); consider using strict_strtoul (checkpatch) > +static struct spacc_alg ipsec_engine_algs[] = { > + { > + .ctrl_default = SPA_CTRL_CIPH_ALG_AES | SPA_CTRL_CIPH_MODE_CBC, > + .key_offs = 0, > + .iv_offs = SPACC_CRYPTO_AES_MAX_KEY_LEN, > + .alg = { > + .cra_name = "cbc(aes)", > + .cra_driver_name = "cbc-aes-picoxcell", > + .cra_priority = SPACC_CRYPTO_ALG_PRIORITY, > + .cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | > + CRYPTO_ALG_ASYNC | > + CRYPTO_ALG_NEED_FALLBACK, > + .cra_blocksize = 16, symbolic constant, here and throughout the rest of this section. Thanks, Kim