From: Corentin Labbe Subject: Re: [PATCH v4 2/2] crypto: stm32 - Support for STM32 CRYP crypto module Date: Thu, 19 Oct 2017 12:34:54 +0200 Message-ID: <20171019103454.GA26877@Red> References: <1508403839-14131-1-git-send-email-fabien.dessenne@st.com> <1508403839-14131-3-git-send-email-fabien.dessenne@st.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Herbert Xu , "David S . Miller" , Rob Herring , Mark Rutland , Maxime Coquelin , Alexandre Torgue , linux-crypto-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Lionel Debieve , Benjamin Gaignard , Ludovic Barre To: Fabien Dessenne Return-path: Content-Disposition: inline In-Reply-To: <1508403839-14131-3-git-send-email-fabien.dessenne-qxv4g6HH51o@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-crypto.vger.kernel.org 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) ? Why not using also directly FLG_XX since CR_XX are arbitray values ? like using instead CR_AES_CBC = FLG_AES | FLG_CBC [...] > +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 [...] > + > +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 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html