Hi Corentin,

On Fri, Apr 21, 2017 at 09:30:56AM +0200, Corentin Labbe wrote:

I have some minor comment below

[?]

quoted

+	/*
+	 * Result Descriptor Ring prepare
+	 */

This is not preferred comment format for one line

Sure.

[...]

quoted

+static int safexcel_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct safexcel_crypto_priv *priv;
+	int i, ret;
+
+	priv = devm_kzalloc(dev, sizeof(struct safexcel_crypto_priv),
+			    GFP_KERNEL);

sizeof(priv) is preferred as asked by checkpatch

[...]

quoted

+		ring_irq = devm_kzalloc(dev, sizeof(struct safexcel_ring_irq_data),
+					GFP_KERNEL);

same comment here

Sure.

[...]

quoted

+#define EIP197_ALG_ARC4				BIT(7)
+#define EIP197_ALG_AES_ECB			BIT(8)
+#define EIP197_ALG_AES_CBC			BIT(9)
+#define EIP197_ALG_AES_CTR_ICM			BIT(10)
+#define EIP197_ALG_AES_OFB			BIT(11)
+#define EIP197_ALG_AES_CFB			BIT(12)
+#define EIP197_ALG_DES_ECB			BIT(13)
+#define EIP197_ALG_DES_CBC			BIT(14)
+#define EIP197_ALG_DES_OFB			BIT(16)
+#define EIP197_ALG_DES_CFB			BIT(17)
+#define EIP197_ALG_3DES_ECB			BIT(18)
+#define EIP197_ALG_3DES_CBC			BIT(19)
+#define EIP197_ALG_3DES_OFB			BIT(21)
+#define EIP197_ALG_3DES_CFB			BIT(22)
+#define EIP197_ALG_MD5				BIT(24)
+#define EIP197_ALG_HMAC_MD5			BIT(25)

Does MD5, DES and 3DES will be added later ?

They might be added yes. And as these bits describe a register used to
configure the engine it's nice to have a proper definition of what all
combinations do.

[...]

quoted

+static const u8 sha1_zero_digest[SHA1_DIGEST_SIZE] = {
+	0xda, 0x39, 0xa3, 0xee, 0x5e, 0x6b, 0x4b, 0x0d, 0x32, 0x55,
+	0xbf, 0xef, 0x95, 0x60, 0x18, 0x90, 0xaf, 0xd8, 0x07, 0x09,
+};
+
+static const u8 sha224_zero_digest[SHA224_DIGEST_SIZE] = {
+	0xd1, 0x4a, 0x02, 0x8c, 0x2a, 0x3a, 0x2b, 0xc9, 0x47, 0x61,
+	0x02, 0xbb, 0x28, 0x82, 0x34, 0xc4, 0x15, 0xa2, 0xb0, 0x1f,
+	0x82, 0x8e, 0xa6, 0x2a, 0xc5, 0xb3, 0xe4, 0x2f
+};
+
+static const u8 sha256_zero_digest[SHA256_DIGEST_SIZE] = {
+	0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14, 0x9a, 0xfb,
+	0xf4, 0xc8, 0x99, 0x6f, 0xb9, 0x24, 0x27, 0xae, 0x41, 0xe4,
+	0x64, 0x9b, 0x93, 0x4c, 0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52,
+	0xb8, 0x55
+};

Thoses structures are already defined in crypto (sha1_zero_message_hash, etc...)
You can use it since you select SHAxxx in Kconfig

That's right, I'll use these definitions instead.

[...]

quoted

+static int safexcel_hmac_init_pad(struct ahash_request *areq,
+				  unsigned int blocksize, const u8 *key,
+				  unsigned int keylen, u8 *ipad, u8 *opad)
+{
+	struct safexcel_ahash_result result;
+	struct scatterlist sg;
+	int ret, i;
+	u8 *keydup;
+
+	if (keylen <= blocksize) {
+		memcpy(ipad, key, keylen);
+	} else {
+		keydup = kmemdup(key, keylen, GFP_KERNEL);
+		if (!keydup)
+			return -ENOMEM;
+
+		ahash_request_set_callback(areq, CRYPTO_TFM_REQ_MAY_BACKLOG,
+					   safexcel_ahash_complete, &result);
+		sg_init_one(&sg, keydup, keylen);
+		ahash_request_set_crypt(areq, &sg, ipad, keylen);
+		init_completion(&result.completion);
+
+		ret = crypto_ahash_digest(areq);
+		if (ret == -EINPROGRESS) {
+			wait_for_completion_interruptible(&result.completion);
+			ret = result.error;
+		}
+
+		/* Avoid leaking */
+		memset(keydup, 0, keylen);

It is safer to use memzero_explicit

Good to know, I'll update.

quoted

+		kfree(keydup);
+
+		if (ret)
+			return ret;
+
+		keylen = crypto_ahash_digestsize(crypto_ahash_reqtfm(areq));
+	}
+
+	memset(ipad + keylen, 0, blocksize - keylen);
+	memcpy(opad, ipad, blocksize);
+
+	for (i = 0; i < blocksize; i++) {
+		ipad[i] ^= 0x36;
+		opad[i] ^= 0x5c;

What are these constant ?

They are defined in the HMAC RFC, as ipad and opad values. See
https://www.ietf.org/rfc/rfc2104.txt.

[...]

quoted

+static int safexcel_hmac_sha1_setkey(struct crypto_ahash *tfm, const u8 *key,
+				     unsigned int keylen)
+{
+	struct safexcel_ahash_ctx *ctx = crypto_tfm_ctx(crypto_ahash_tfm(tfm));
+	struct safexcel_ahash_export_state istate, ostate;
+	int ret, i;
+
+	ret = safexcel_hmac_setkey("safexcel-sha1", key, keylen, &istate, &ostate);

Perhaps you could use the algname instead of "safexcel-sha1"

No we can't (as of now), because using the SHA implementation of this
driver for partial hashes require special treatments (which we do).

quoted

+	if (ret)
+		return ret;
+
+	memcpy(ctx->ipad, &istate.state, SHA1_DIGEST_SIZE);
+	memcpy(ctx->opad, &ostate.state, SHA1_DIGEST_SIZE);

Perhaps you could the digest_size from alg_template

Well, this HMAC setkey function is dedicated to SHA1 for other reasons
than only this digest size. So why bother retrieving something which we
know is already fixed?

[...]

quoted

+struct safexcel_alg_template safexcel_alg_sha256 = {
+	.type = SAFEXCEL_ALG_TYPE_AHASH,
+	.alg.ahash = {
+		.init = safexcel_sha256_init,
+		.update = safexcel_ahash_update,
+		.final = safexcel_ahash_final,
+		.finup = safexcel_ahash_finup,
+		.digest = safexcel_sha256_digest,
+		.export = safexcel_ahash_export,
+		.import = safexcel_ahash_import,
+		.halg = {
+			.digestsize = SHA256_DIGEST_SIZE,
+			.statesize = sizeof(struct safexcel_ahash_export_state),
+			.base = {
+				.cra_name = "sha256",
+				.cra_driver_name = "safexcel-sha256",
+				.cra_priority = 300,
+				.cra_flags = CRYPTO_ALG_ASYNC |
+					     CRYPTO_ALG_KERN_DRIVER_ONLY,

Why do use CRYPTO_ALG_KERN_DRIVER_ONLY ?

See http://lxr.free-electrons.com/source/include/linux/crypto.h#L97.

Thanks,
Antoine

-- 
Antoine T?nart, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 801 bytes
Desc: not available
URL: <http://lists.infradead.org/pipermail/linux-arm-kernel/attachments/20170421/11564af3/attachment-0001.sig>