From: Neil Armstrong Subject: Re: [PATCH v4 2/2] crypto: stm32 - Support for STM32 CRYP crypto module Date: Thu, 19 Oct 2017 15:47:08 +0200 Message-ID: References: <1508403839-14131-1-git-send-email-fabien.dessenne@st.com> <1508403839-14131-3-git-send-email-fabien.dessenne@st.com> <20171019103454.GA26877@Red> <0359a8aa-5d91-6284-76cb-44bbd7865a0f@st.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Cc: Mark Rutland , "devicetree@vger.kernel.org" , Alexandre TORGUE , "linux-kernel@vger.kernel.org" , Lionel DEBIEVE , Rob Herring , "linux-crypto@vger.kernel.org" , Maxime Coquelin , Benjamin GAIGNARD , Ludovic BARRE , "David S . Miller" , "linux-arm-kernel@lists.infradead.org" , Herbert Xu To: Fabien DESSENNE , Corentin Labbe Return-path: In-Reply-To: <0359a8aa-5d91-6284-76cb-44bbd7865a0f@st.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-crypto.vger.kernel.org On 19/10/2017 15:01, Fabien DESSENNE wrote: > Hi Corentin > > > Thank you for your comments. I will fix according to them. See also me > answers/questions below > > While we are at it, do you plan to deliver a new version of the > crypto_engine update? (I had to remove the AEAD part of this new driver > since it depends on that pending update) > > BR > > Fabien > > > On 19/10/17 12:34, Corentin Labbe wrote: >> Hello >> >> I have some minor comment below >> >> On Thu, Oct 19, 2017 at 11:03:59AM +0200, Fabien Dessenne wrote: >>> This module registers block cipher algorithms that make use of the >>> STMicroelectronics STM32 crypto "CRYP1" hardware. >>> The following algorithms are supported: >>> - aes: ecb, cbc, ctr >>> - des: ecb, cbc >>> - tdes: ecb, cbc >>> >>> Signed-off-by: Fabien Dessennie >>> --- >>> drivers/crypto/stm32/Kconfig | 9 + >>> drivers/crypto/stm32/Makefile | 3 +- >>> drivers/crypto/stm32/stm32-cryp.c | 1188 +++++++++++++++++++++++++++++++++++++ >>> 3 files changed, 1199 insertions(+), 1 deletion(-) >>> create mode 100644 drivers/crypto/stm32/stm32-cryp.c >>> >>> diff --git a/drivers/crypto/stm32/Kconfig b/drivers/crypto/stm32/Kconfig >>> index 602332e..61ef00b 100644 >>> --- a/drivers/crypto/stm32/Kconfig >>> +++ b/drivers/crypto/stm32/Kconfig >> [...] >>> +/* Bit [0] encrypt / decrypt */ >>> +#define FLG_ENCRYPT BIT(0) >>> +/* Bit [8..1] algo & operation mode */ >>> +#define FLG_AES BIT(1) >>> +#define FLG_DES BIT(2) >>> +#define FLG_TDES BIT(3) >>> +#define FLG_ECB BIT(4) >>> +#define FLG_CBC BIT(5) >>> +#define FLG_CTR BIT(6) >>> +/* Mode mask = bits [15..0] */ >>> +#define FLG_MODE_MASK GENMASK(15, 0) >>> + >>> +/* Registers */ >>> +#define CRYP_CR 0x00000000 >>> +#define CRYP_SR 0x00000004 >>> +#define CRYP_DIN 0x00000008 >>> +#define CRYP_DOUT 0x0000000C >>> +#define CRYP_DMACR 0x00000010 >>> +#define CRYP_IMSCR 0x00000014 >>> +#define CRYP_RISR 0x00000018 >>> +#define CRYP_MISR 0x0000001C >>> +#define CRYP_K0LR 0x00000020 >>> +#define CRYP_K0RR 0x00000024 >>> +#define CRYP_K1LR 0x00000028 >>> +#define CRYP_K1RR 0x0000002C >>> +#define CRYP_K2LR 0x00000030 >>> +#define CRYP_K2RR 0x00000034 >>> +#define CRYP_K3LR 0x00000038 >>> +#define CRYP_K3RR 0x0000003C >>> +#define CRYP_IV0LR 0x00000040 >>> +#define CRYP_IV0RR 0x00000044 >>> +#define CRYP_IV1LR 0x00000048 >>> +#define CRYP_IV1RR 0x0000004C >>> + >>> +/* Registers values */ >>> +#define CR_DEC_NOT_ENC 0x00000004 >>> +#define CR_TDES_ECB 0x00000000 >>> +#define CR_TDES_CBC 0x00000008 >>> +#define CR_DES_ECB 0x00000010 >>> +#define CR_DES_CBC 0x00000018 >>> +#define CR_AES_ECB 0x00000020 >>> +#define CR_AES_CBC 0x00000028 >>> +#define CR_AES_CTR 0x00000030 >>> +#define CR_AES_KP 0x00000038 >>> +#define CR_AES_UNKNOWN 0xFFFFFFFF >>> +#define CR_ALGO_MASK 0x00080038 >>> +#define CR_DATA32 0x00000000 >>> +#define CR_DATA16 0x00000040 >>> +#define CR_DATA8 0x00000080 >>> +#define CR_DATA1 0x000000C0 >>> +#define CR_KEY128 0x00000000 >>> +#define CR_KEY192 0x00000100 >>> +#define CR_KEY256 0x00000200 >>> +#define CR_FFLUSH 0x00004000 >>> +#define CR_CRYPEN 0x00008000 >> Why not using BIT(x) ? > > Some values are not only 1 bit (then we may use BIT and BITGEN but this > would be less readable), so I prefer to keep this values. You can use GENMASK and the corresponding FIELD_PREP() and FIELD_GET(). It avoids manipulating the bits directly. > >> Why not using also directly FLG_XX since CR_XX are arbitray values ? like using instead CR_AES_CBC = FLG_AES | FLG_CBC > > The CR_ values are used to write in the registers. FLG_ are arbitraty > values, so we cannot mix them. > >> >> [...] >>> +static inline void stm32_cryp_wait_enable(struct stm32_cryp *cryp) >>> +{ >>> + while (stm32_cryp_read(cryp, CRYP_CR) & CR_CRYPEN) >>> + cpu_relax(); >>> +} >> This function is not used, so you could remove it >> >>> + >>> +static inline void stm32_cryp_wait_busy(struct stm32_cryp *cryp) >>> +{ >>> + while (stm32_cryp_read(cryp, CRYP_SR) & SR_BUSY) >>> + cpu_relax(); >>> +} >> No timeout ? >> >> >>> + >>> +static inline void stm32_cryp_wait_output(struct stm32_cryp *cryp) >>> +{ >>> + while (!(stm32_cryp_read(cryp, CRYP_SR) & SR_OFNE)) >>> + cpu_relax(); >>> +} >> This function is not used, so you could remove it >> >> [...] >>> +static int stm32_cryp_check_aligned(struct scatterlist *sg, size_t total, >>> + size_t align) >>> +{ >>> + int len = 0; >>> + >>> + if (!total) >>> + return 0; >>> + >>> + if (!IS_ALIGNED(total, align)) >>> + return -EINVAL; >>> + >>> + while (sg) { >>> + if (!IS_ALIGNED(sg->offset, sizeof(u32))) >>> + return -1; >> -1 is not a good return value, prefer any -Exxxx >> >>> + >>> + if (!IS_ALIGNED(sg->length, align)) >>> + return -1; >>> + >>> + len += sg->length; >>> + sg = sg_next(sg); >>> + } >>> + >>> + if (len != total) >>> + return -1; >> [...] >>> +static int stm32_cryp_copy_sgs(struct stm32_cryp *cryp) >>> +{ >>> + void *buf_in, *buf_out; >>> + int pages, total_in, total_out; >>> + >>> + if (!stm32_cryp_check_io_aligned(cryp)) { >>> + cryp->sgs_copied = 0; >>> + return 0; >>> + } >>> + >>> + total_in = ALIGN(cryp->total_in, cryp->hw_blocksize); >>> + pages = total_in ? get_order(total_in) : 1; >>> + buf_in = (void *)__get_free_pages(GFP_ATOMIC, pages); >>> + >>> + total_out = ALIGN(cryp->total_out, cryp->hw_blocksize); >>> + pages = total_out ? get_order(total_out) : 1; >>> + buf_out = (void *)__get_free_pages(GFP_ATOMIC, pages); >>> + >>> + if (!buf_in || !buf_out) { >>> + pr_err("Couldn't allocate pages for unaligned cases.\n"); >> You must use dev_err() instead. without it, it will be hard to know which subsystem said that error message. >> >> [...] >>> +static int stm32_cryp_cra_init(struct crypto_tfm *tfm) >>> +{ >>> + tfm->crt_ablkcipher.reqsize = sizeof(struct stm32_cryp_reqctx); >>> + >>> + return 0; >>> +} >> You could simply remove this function > > I am not sure we can. Here we set reqsize. > Most of the other drivers do the same, but maybe this is wrong everywhere. > Could you give more details? > >> >> [...] >>> + >>> +static void stm32_cryp_cra_exit(struct crypto_tfm *tfm) >>> +{ >>> +} >>> + >>> +static int stm32_cryp_crypt(struct ablkcipher_request *req, unsigned long mode) >>> +{ >>> + struct stm32_cryp_ctx *ctx = crypto_ablkcipher_ctx( >>> + crypto_ablkcipher_reqtfm(req)); >>> + struct stm32_cryp_reqctx *rctx = ablkcipher_request_ctx(req); >>> + struct stm32_cryp *cryp = stm32_cryp_find_dev(ctx); >>> + >>> + if (!cryp) >>> + return -ENODEV; >>> + >>> + rctx->mode = mode; >>> + >>> + return crypto_transfer_cipher_request_to_engine(cryp->engine, req); >>> +} >>> + >>> +static int stm32_cryp_setkey(struct crypto_ablkcipher *tfm, const u8 *key, >>> + unsigned int keylen) >>> +{ >>> + struct stm32_cryp_ctx *ctx = crypto_ablkcipher_ctx(tfm); >>> + >>> + memcpy(ctx->key, key, keylen); >>> + ctx->keylen = keylen; >> You never zeroize the key after request. >> >> [...] >>> +static const struct of_device_id stm32_dt_ids[] = { >>> + { .compatible = "st,stm32f756-cryp", }, >>> + {}, >>> +}; >>> +MODULE_DEVICE_TABLE(of, sti_dt_ids); >>> + >>> +static int stm32_cryp_probe(struct platform_device *pdev) >>> +{ >>> + struct device *dev = &pdev->dev; >>> + struct stm32_cryp *cryp; >>> + struct resource *res; >>> + struct reset_control *rst; >>> + const struct of_device_id *match; >>> + int irq, ret; >>> + >>> + cryp = devm_kzalloc(dev, sizeof(*cryp), GFP_KERNEL); >>> + if (!cryp) >>> + return -ENOMEM; >>> + >>> + match = of_match_device(stm32_dt_ids, dev); >>> + if (!match) >>> + return -ENODEV; >> I think this test is unnecessary, at least it should be before the devm_kzalloc >> >> Regards > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel >