From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753815AbbDBTMA (ORCPT ); Thu, 2 Apr 2015 15:12:00 -0400 Received: from mail-wg0-f45.google.com ([74.125.82.45]:34792 "EHLO mail-wg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753200AbbDBTL4 (ORCPT ); Thu, 2 Apr 2015 15:11:56 -0400 Message-ID: <551D9476.7090206@gmail.com> Date: Thu, 02 Apr 2015 21:11:50 +0200 From: Corentin LABBE User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: Boris Brezillon CC: robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, maxime.ripard@free-electrons.com, linux@arm.linux.org.uk, herbert@gondor.apana.org.au, davem@davemloft.net, akpm@linux-foundation.org, gregkh@linuxfoundation.org, arnd@arndb.de, devicetree@vger.kernel.org, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org, linux-sunxi@googlegroups.com Subject: Re: [PATCH v6 4/4] crypto: Add Allwinner Security System crypto accelerator References: <1426532482-28830-1-git-send-email-clabbe.montjoie@gmail.com> <1426532482-28830-5-git-send-email-clabbe.montjoie@gmail.com> <20150326193115.5e30a9af@bbrezillon> In-Reply-To: <20150326193115.5e30a9af@bbrezillon> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 26/03/2015 19:31, Boris Brezillon a écrit : > Hi Corentin, > > Here is a quick review, there surely are a lot of other things I didn't > spot. > > On Mon, 16 Mar 2015 20:01:22 +0100 > LABBE Corentin wrote: > >> Add support for the Security System included in Allwinner SoC A20. >> The Security System is a hardware cryptographic accelerator that support: >> - MD5 and SHA1 hash algorithms >> - AES block cipher in CBC mode with 128/196/256bits keys. >> - DES and 3DES block cipher in CBC mode >> >> Signed-off-by: LABBE Corentin >> --- > > [...] > >> +static int sunxi_ss_cipher(struct ablkcipher_request *areq, u32 mode) >> +{ >> + struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq); >> + struct sunxi_tfm_ctx *op = crypto_ablkcipher_ctx(tfm); >> + const char *cipher_type; >> + struct sunxi_ss_ctx *ss = op->ss; >> + >> + if (areq->nbytes == 0) >> + return 0; >> + >> + if (areq->info == NULL) { >> + dev_err(ss->dev, "ERROR: Empty IV\n"); >> + return -EINVAL; >> + } >> + >> + if (areq->src == NULL || areq->dst == NULL) { >> + dev_err(ss->dev, "ERROR: Some SGs are NULL\n"); >> + return -EINVAL; >> + } >> + >> + cipher_type = crypto_tfm_alg_name(crypto_ablkcipher_tfm(tfm)); >> + >> + if (strcmp("cbc(aes)", cipher_type) == 0) { >> + mode |= SS_OP_AES | SS_CBC | SS_ENABLED | op->keymode; >> + return sunxi_ss_aes_poll(areq, mode); >> + } >> + >> + if (strcmp("cbc(des)", cipher_type) == 0) { >> + mode |= SS_OP_DES | SS_CBC | SS_ENABLED | op->keymode; >> + return sunxi_ss_des_poll(areq, mode); >> + } >> + >> + if (strcmp("cbc(des3_ede)", cipher_type) == 0) { >> + mode |= SS_OP_3DES | SS_CBC | SS_ENABLED | op->keymode; >> + return sunxi_ss_des_poll(areq, mode); >> + } > > Hm, I'm not sure doing these string comparisons in the crypto operation > path is a good idea. > Moreover, you're doing 3 string comparisons, even though only one can > be valid at a time (using 'else if' would have been a bit better). > > Anyway, IMHO this function should be split into 3 functions, and > referenced by your alg template definitions. > Something like: > > int sunxi_ss_xxx_encrypt(struct ablkcipher_request *areq) > { > /* put your cipher specific intialization here */ > > return sunxi_ss_xxx_poll(areq, SS_ENCRYPTION); > } > > int sunxi_ss_xxx_decrypt(struct ablkcipher_request *areq) > { > /* put your cipher specific intialization here */ > > return sunxi_ss_xxx_poll(areq, SS_DECRYPTION); > } > You are right, I have added more block mode, and that was added too much strcmp. So splitting in simplier functions is good. > >> + >> +int sunxi_ss_cipher_init(struct crypto_tfm *tfm) >> +{ >> + const char *name = crypto_tfm_alg_name(tfm); >> + struct sunxi_tfm_ctx *op = crypto_tfm_ctx(tfm); >> + struct crypto_alg *alg = tfm->__crt_alg; >> + struct sunxi_ss_alg_template *algt; >> + struct sunxi_ss_ctx *ss; >> + >> + memset(op, 0, sizeof(struct sunxi_tfm_ctx)); >> + >> + algt = container_of(alg, struct sunxi_ss_alg_template, alg.crypto); >> + ss = algt->ss; >> + op->ss = algt->ss; >> + >> + /* fallback is needed only for DES/3DES */ >> + if (strcmp("cbc(des)", name) == 0 || >> + strcmp("cbc(des3_ede)", name) == 0) { >> + op->fallback = crypto_alloc_ablkcipher(name, 0, >> + CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK); >> + if (IS_ERR(op->fallback)) { >> + dev_err(ss->dev, "ERROR: allocating fallback algo %s\n", >> + name); >> + return PTR_ERR(op->fallback); >> + } >> + } > > Ditto: just create a specific init function for the des case: > > int sunxi_ss_cbc_des_init(struct crypto_tfm *tfm) > { > sunxi_ss_cipher_init(tfm); > > op->fallback = crypto_alloc_ablkcipher(name, 0, > CRYPTO_ALG_ASYNC | > CRYPTO_ALG_NEED_FALLBACK); > if (IS_ERR(op->fallback)) { > dev_err(ss->dev, "ERROR: allocating fallback algo %s\n", > name); > return PTR_ERR(op->fallback); > } > > return 0; > } > Ok > > [..] > >> +/* >> + * Optimized function for the case where we have only one SG, >> + * so we can use kmap_atomic >> + */ >> +static int sunxi_ss_aes_poll_atomic(struct ablkcipher_request *areq) >> +{ >> + u32 spaces; >> + struct scatterlist *in_sg = areq->src; >> + struct scatterlist *out_sg = areq->dst; >> + void *src_addr; >> + void *dst_addr; >> + unsigned int ileft = areq->nbytes; >> + unsigned int oleft = areq->nbytes; >> + unsigned int todo; >> + u32 *src32; >> + u32 *dst32; >> + u32 rx_cnt = 32; >> + u32 tx_cnt = 0; >> + int i; >> + struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq); >> + struct sunxi_tfm_ctx *op = crypto_ablkcipher_ctx(tfm); >> + struct sunxi_ss_ctx *ss = op->ss; >> + >> + src_addr = kmap_atomic(sg_page(in_sg)) + in_sg->offset; >> + if (src_addr == NULL) { >> + dev_err(ss->dev, "kmap_atomic error for src SG\n"); >> + return -EINVAL; >> + } >> + >> + dst_addr = kmap_atomic(sg_page(out_sg)) + out_sg->offset; >> + if (dst_addr == NULL) { >> + dev_err(ss->dev, "kmap_atomic error for dst SG\n"); >> + kunmap_atomic(src_addr); >> + return -EINVAL; >> + } >> + >> + src32 = (u32 *)src_addr; >> + dst32 = (u32 *)dst_addr; >> + ileft = areq->nbytes / 4; >> + oleft = areq->nbytes / 4; >> + i = 0; >> + do { >> + if (ileft > 0 && rx_cnt > 0) { >> + todo = min(rx_cnt, ileft); >> + ileft -= todo; >> + writesl(ss->base + SS_RXFIFO, src32, todo); >> + src32 += todo; >> + } >> + if (tx_cnt > 0) { >> + todo = min(tx_cnt, oleft); >> + oleft -= todo; >> + readsl(ss->base + SS_TXFIFO, dst32, todo); >> + dst32 += todo; >> + } >> + spaces = readl(ss->base + SS_FCSR); >> + rx_cnt = SS_RXFIFO_SPACES(spaces); >> + tx_cnt = SS_TXFIFO_SPACES(spaces); >> + } while (oleft > 0); >> + kunmap_atomic(dst_addr); >> + kunmap_atomic(src_addr); >> + return 0; >> +} >> + >> +int sunxi_ss_aes_poll(struct ablkcipher_request *areq, u32 mode) >> +{ >> + u32 spaces; >> + struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq); >> + struct sunxi_tfm_ctx *op = crypto_ablkcipher_ctx(tfm); >> + struct sunxi_ss_ctx *ss = op->ss; >> + unsigned int ivsize = crypto_ablkcipher_ivsize(tfm); >> + /* when activating SS, the default FIFO space is 32 */ >> + u32 rx_cnt = 32; >> + u32 tx_cnt = 0; >> + u32 v; >> + int i, err = 0; >> + struct scatterlist *in_sg = areq->src; >> + struct scatterlist *out_sg = areq->dst; >> + void *src_addr; >> + void *dst_addr; >> + unsigned int ileft = areq->nbytes; >> + unsigned int oleft = areq->nbytes; >> + unsigned int sgileft = areq->src->length; >> + unsigned int sgoleft = areq->dst->length; >> + unsigned int todo; >> + u32 *src32; >> + u32 *dst32; >> + unsigned long flags; >> + >> + spin_lock_irqsave(&ss->slock, flags); >> + >> + for (i = 0; i < op->keylen; i += 4) >> + writel(*(op->key + i/4), ss->base + SS_KEY0 + i); >> + >> + if (areq->info != NULL) { >> + for (i = 0; i < 4 && i < ivsize / 4; i++) { >> + v = *(u32 *)(areq->info + i * 4); >> + writel(v, ss->base + SS_IV0 + i * 4); >> + } >> + } >> + writel(mode, ss->base + SS_CTL); >> + >> + /* If we have only one SG, we can use kmap_atomic */ >> + if (sg_next(in_sg) == NULL && sg_next(out_sg) == NULL) { >> + err = sunxi_ss_aes_poll_atomic(areq); >> + goto release_ss; >> + } >> + >> + /* >> + * If we have more than one SG, we cannot use kmap_atomic since >> + * we hold the mapping too long >> + */ >> + src_addr = kmap(sg_page(in_sg)) + in_sg->offset; >> + if (src_addr == NULL) { >> + dev_err(ss->dev, "KMAP error for src SG\n"); >> + err = -EINVAL; >> + goto release_ss; >> + } >> + dst_addr = kmap(sg_page(out_sg)) + out_sg->offset; >> + if (dst_addr == NULL) { >> + kunmap(sg_page(in_sg)); >> + dev_err(ss->dev, "KMAP error for dst SG\n"); >> + err = -EINVAL; >> + goto release_ss; >> + } >> + src32 = (u32 *)src_addr; >> + dst32 = (u32 *)dst_addr; >> + ileft = areq->nbytes / 4; >> + oleft = areq->nbytes / 4; >> + sgileft = in_sg->length / 4; >> + sgoleft = out_sg->length / 4; >> + do { >> + spaces = readl_relaxed(ss->base + SS_FCSR); >> + rx_cnt = SS_RXFIFO_SPACES(spaces); >> + tx_cnt = SS_TXFIFO_SPACES(spaces); >> + todo = min3(rx_cnt, ileft, sgileft); >> + if (todo > 0) { >> + ileft -= todo; >> + sgileft -= todo; >> + writesl(ss->base + SS_RXFIFO, src32, todo); >> + src32 += todo; >> + } >> + if (in_sg != NULL && sgileft == 0 && ileft > 0) { >> + kunmap(sg_page(in_sg)); >> + in_sg = sg_next(in_sg); >> + while (in_sg != NULL && in_sg->length == 0) >> + in_sg = sg_next(in_sg); >> + if (in_sg != NULL && ileft > 0) { >> + src_addr = kmap(sg_page(in_sg)) + in_sg->offset; >> + if (src_addr == NULL) { >> + dev_err(ss->dev, "ERROR: KMAP for src SG\n"); >> + err = -EINVAL; >> + goto release_ss; >> + } >> + src32 = src_addr; >> + sgileft = in_sg->length / 4; >> + } >> + } >> + /* do not test oleft since when oleft == 0 we have finished */ >> + todo = min3(tx_cnt, oleft, sgoleft); >> + if (todo > 0) { >> + oleft -= todo; >> + sgoleft -= todo; >> + readsl(ss->base + SS_TXFIFO, dst32, todo); >> + dst32 += todo; >> + } >> + if (out_sg != NULL && sgoleft == 0 && oleft >= 0) { >> + kunmap(sg_page(out_sg)); >> + out_sg = sg_next(out_sg); >> + while (out_sg != NULL && out_sg->length == 0) >> + out_sg = sg_next(out_sg); >> + if (out_sg != NULL && oleft > 0) { >> + dst_addr = kmap(sg_page(out_sg)) + >> + out_sg->offset; >> + if (dst_addr == NULL) { >> + dev_err(ss->dev, "KMAP error\n"); >> + err = -EINVAL; >> + goto release_ss; >> + } >> + dst32 = dst_addr; >> + sgoleft = out_sg->length / 4; >> + } >> + } >> + } while (oleft > 0); >> + >> +release_ss: >> + writel_relaxed(0, ss->base + SS_CTL); >> + spin_unlock_irqrestore(&ss->slock, flags); >> + return err; >> +} > > Do you really need to have both an "optimized" and "non-optimized" > function ? > > BTW, you should take a look at the sg_copy_buffer function [1], which > is doing pretty much what you're doing here. > If you don't want to directly use sg_copy_buffer, you should at least > use the sg_miter_xxx function to iterate over you're sg list (it's > taking care of calling kmap or kmap_atomic depending on the > SG_MITER_ATOMIC flag). > I have dropped sg_copy_buffer that I used for DES/3DES some times ago for handling SG with length not multiple of 4. And using sg_miter is not usefull. It could be usefull for DES/3DEs for non 4 bytes multiple SG, but I use a fallback for that case. >> + >> +/* Pure CPU driven way of doing DES/3DES with SS */ >> +int sunxi_ss_des_poll(struct ablkcipher_request *areq, u32 mode) >> +{ >> + struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq); >> + struct sunxi_tfm_ctx *op = crypto_ablkcipher_ctx(tfm); >> + struct sunxi_ss_ctx *ss = op->ss; >> + int i, err = 0; >> + int no_chunk = 1; >> + struct scatterlist *in_sg = areq->src; >> + struct scatterlist *out_sg = areq->dst; >> + u8 kkey[256 / 8]; >> + >> + /* >> + * if we have only SGs with size multiple of 4, >> + * we can use the SS AES function >> + */ >> + while (in_sg != NULL && no_chunk == 1) { >> + if ((in_sg->length % 4) != 0) >> + no_chunk = 0; >> + in_sg = sg_next(in_sg); >> + } >> + while (out_sg != NULL && no_chunk == 1) { >> + if ((out_sg->length % 4) != 0) >> + no_chunk = 0; >> + out_sg = sg_next(out_sg); >> + } >> + >> + if (no_chunk == 1) >> + return sunxi_ss_aes_poll(areq, mode); >> + > > Given your explanations, I'm not sure the names sunxi_ss_aes_poll and > sunxi_ss_des_poll are appropriate. > > What about sunxi_ss_aligned_cipher_op_poll and sunxi_ss_cipher_op_poll. The difference is not about aligned or not since according to my understanding, the data will always be aligned following cra_alignmask. Thanks for your review > > That's all I got for now. > I haven't reviewed the hash part yet, but I guess some of my comments > apply to this code too. > > Best Regards, > > Boris > > > [1]http://lxr.free-electrons.com/source/lib/scatterlist.c#L621 >