From: Fabien DESSENNE Subject: Re: [PATCH v4 2/2] crypto: stm32 - Support for STM32 CRYP crypto module Date: Thu, 19 Oct 2017 13:01:56 +0000 Message-ID: <0359a8aa-5d91-6284-76cb-44bbd7865a0f@st.com> References: <1508403839-14131-1-git-send-email-fabien.dessenne@st.com> <1508403839-14131-3-git-send-email-fabien.dessenne@st.com> <20171019103454.GA26877@Red> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" 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: Corentin Labbe Return-path: In-Reply-To: <20171019103454.GA26877@Red> Content-Language: en-US Content-ID: <5BFA05B473DBD04D8B576295F8FC5246@st.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org List-Id: linux-crypto.vger.kernel.org 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. > 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