Le 14/06/2014 21:01, Marek Vasut a ?crit :

On Tuesday, June 10, 2014 at 02:43:14 PM, LABBE Corentin wrote:

quoted

Add support for the Security System included in Allwinner SoC A20.
The Security System is a hardware cryptographic accelerator that support
AES/MD5/SHA1/DES/3DES/PRNG algorithms.

Signed-off-by: LABBE Corentin <clabbe.montjoie@gmail.com>

[...]

quoted

diff --git a/drivers/crypto/sunxi-ss/sunxi-ss-cipher-3des.c

b/drivers/crypto/sunxi-ss/sunxi-ss-cipher-3des.c new file mode 100644
index 0000000..fcdc8a4

--- /dev/null
+++ b/drivers/crypto/sunxi-ss/sunxi-ss-cipher-3des.c

@@ -0,0 +1,118 @@
+/*
+ * sunxi-ss.c - hardware cryptographic accelerator for Allwinner A20 SoC
+ *
+ * Copyright (C) 2013-2014 Corentin LABBE <clabbe.montjoie@gmail.com>
+ *
+ * Support AES cipher with 128,192,256 bits keysize.
+ * Support MD5 and SHA1 hash algorithms.
+ * Support DES and 3DES
+ * Support PRNG
+ *
+ * You could find the datasheet at
+ * http://dl.linux-sunxi.org/A20/A20%20User%20Manual%202013-03-22.pdf
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation version 2 of the License

The license text seems incomplete.
[...]

I will replace it with a simplier line "Licensed under the GPL-2."

quoted

+static int sunxi_des3_cbc_encrypt(struct ablkcipher_request *areq)
+{
+	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq);
+	struct sunxi_req_ctx *op = crypto_ablkcipher_ctx(tfm);
+
+	if (areq->info == NULL) {
+		dev_info(ss->dev, "Empty IV\n");

dev_err() here.

quoted

+		return -EINVAL;
+	}
+
+	op->mode |= SS_ENCRYPTION;
+	op->mode |= SS_OP_3DES;
+	op->mode |= SS_CBC;

You can just op |= (foo | bar | baz) here .

quoted

+	return sunxi_des_poll(areq);
+}
+
+static int sunxi_des3_cbc_decrypt(struct ablkcipher_request *areq)
+{
+	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq);
+	struct sunxi_req_ctx *op = crypto_ablkcipher_ctx(tfm);
+
+	if (areq->info == NULL) {
+		dev_info(ss->dev, "Empty IV\n");

DTTO.

quoted

+		return -EINVAL;
+	}
+
+	op->mode |= SS_DECRYPTION;
+	op->mode |= SS_OP_3DES;
+	op->mode |= SS_CBC;

DTTO.

[...]

quoted

+static int sunxi_ss_3des_init(void)
+{
+	int err = 0;
+	if (ss == NULL) {
+		pr_err("Cannot get Security System structure\n");
+		return -ENODEV;
+	}
+	err = crypto_register_alg(&sunxi_des3_alg);
+	if (err)
+		dev_err(ss->dev, "crypto_register_alg error for DES3\n");
+	else
+		dev_dbg(ss->dev, "Registred DES3\n");
+	return err;
+}
+
+static void __exit sunxi_ss_3des_exit(void)
+{
+	crypto_unregister_alg(&sunxi_des3_alg);
+}
+
+module_init(sunxi_ss_3des_init);
+module_exit(sunxi_ss_3des_exit);

I really dislike how you have multiple modules accessing the same hardware. That 
just seems broken.

OK I abort my tries to make things optionnal.

[...]

quoted

+static int sunxi_aes_cbc_encrypt(struct ablkcipher_request *areq)
+{
+	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq);
+	struct sunxi_req_ctx *op = crypto_ablkcipher_ctx(tfm);
+
+	if (areq->info == NULL) {
+		dev_err(ss->dev, "Empty IV\n");
+		return -EINVAL;
+	}
+
+	op->mode |= SS_ENCRYPTION;
+	op->mode |= SS_OP_AES;
+	op->mode |= SS_CBC;

This looks just like the 3DES implementation. Please make this into a common 
code if possible. I think you'd just need to have some switch statement based on 
the type of cipher to fill op->mode, that's all.

I agree, I will simplify that.

quoted

+	return sunxi_aes_poll(areq);
+}

[...]

quoted

+static int sunxi_des_cbc_encrypt(struct ablkcipher_request *areq)
+{
+	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq);
+	struct sunxi_req_ctx *op = crypto_ablkcipher_ctx(tfm);
+
+	if (areq->info == NULL) {
+		dev_info(ss->dev, "Empty IV\n");
+		return -EINVAL;
+	}
+
+	op->mode |= SS_ENCRYPTION;
+	op->mode |= SS_OP_DES;
+	op->mode |= SS_CBC;

Looks similar to 3DES and AES again.

quoted

+	return sunxi_des_poll(areq);
+}

[...]

quoted

diff --git a/drivers/crypto/sunxi-ss/sunxi-ss-cipher.c

b/drivers/crypto/sunxi-ss/sunxi-ss-cipher.c new file mode 100644
index 0000000..a27de49

[...]

quoted

+int sunxi_cipher_init(struct crypto_tfm *tfm)
+{
+	struct sunxi_req_ctx *op = crypto_tfm_ctx(tfm);
+	memset(op, 0, sizeof(struct sunxi_req_ctx));
+	return 0;
+}
+EXPORT_SYMBOL_GPL(sunxi_cipher_init);

This is wrong, you don't want to export this symbol.

quoted

+void sunxi_cipher_exit(struct crypto_tfm *tfm)
+{
+}
+EXPORT_SYMBOL_GPL(sunxi_cipher_exit);

Why do you even need an empty function ?

Ok, I will clean that

quoted

+int sunxi_aes_poll(struct ablkcipher_request *areq)
+{
+	u32 tmp;
+	struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(areq);
+	struct sunxi_req_ctx *op = crypto_ablkcipher_ctx(tfm);
+	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;
+	struct scatterlist *in_sg;
+	struct scatterlist *out_sg;
+	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;
+
+	tmp = op->mode;
+	tmp |= SS_ENABLED;

tmp is not a good name for a variable .

renamed to mode

quoted

+	in_sg = areq->src;
+	out_sg = areq->dst;
+	if (areq->src == NULL || areq->dst == NULL) {

You do a NULL pointer test here, yet you access areq->src->length in sgileft 
above . DTTO for areq->dst->length . That would crash much earlier than here.

quoted

+		dev_err(ss->dev, "ERROR: Some SGs are NULL %u\n", areq->nbytes);
+		return -1;
+	}
+	mutex_lock(&ss->lock);
+	if (areq->info != NULL) {
+		for (i = 0; i < op->keylen; i += 4) {
+			v = *(u32 *)(op->key + i);

Consider that op->key would be magically unaligned ... then you'd trigger 
alignment fault here. Make the "op->key" an u32[] and drop those crap casts 
here.

I Agree

quoted

+			writel(v, ss->base + SS_KEY0 + i);
+		}
+		for (i = 0; i < 4 && i < ivsize / 4; i++) {
+			v = *(u32 *)(areq->info + i * 4);
+			writel(v, ss->base + SS_IV0 + i * 4);
+		}
+	}
+	writel(tmp, 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) {
+		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");
+			writel(0, ss->base + SS_CTL);
+			mutex_unlock(&ss->lock);
+			return -1;

-EINVAL ?

quoted

+		}
+		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");
+			writel(0, ss->base + SS_CTL);
+			mutex_unlock(&ss->lock);
+			kunmap_atomic(src_addr);
+			return -1;

-EINVAL ?

quoted

+		}
+		src32 = (u32 *)src_addr;
+		dst32 = (u32 *)dst_addr;
+		ileft = areq->nbytes / 4;
+		oleft = areq->nbytes / 4;
+		do {
+			if (ileft > 0 && rx_cnt > 0) {
+				todo = min(rx_cnt, ileft);
+				ileft -= todo;
+				do {
+					writel_relaxed(*src32++,
+						       ss->base +
+						       SS_RXFIFO);
+					todo--;
+				} while (todo > 0);
+			}
+			if (tx_cnt > 0) {
+				todo = min(tx_cnt, oleft);
+				oleft -= todo;
+				do {
+					*dst32++ = readl_relaxed(ss->base +
+								SS_TXFIFO);
+					todo--;
+				} while (todo > 0);
+			}
+			tmp = readl_relaxed(ss->base + SS_FCSR);
+			rx_cnt = SS_RXFIFO_SPACES(tmp);
+			tx_cnt = SS_TXFIFO_SPACES(tmp);
+		} while (oleft > 0);
+		writel(0, ss->base + SS_CTL);
+		mutex_unlock(&ss->lock);
+		kunmap_atomic(src_addr);
+		kunmap_atomic(dst_addr);
+		return 0;
+	}
+
+	/* If we have more than one SG, we cannot use kmap_atomic since
+	 * we hold the mapping too long*/

Wrong comment style.

btw. can't you use generic scatterwalk here ?

I will check if it simplify the code.

quoted

+	src_addr = kmap(sg_page(in_sg)) + in_sg->offset;
+	if (src_addr == NULL) {
+		dev_err(ss->dev, "KMAP error for src SG\n");
+		return -1;
+	}

Why can't you just use dma_map_sg() or somesuch ?

I do not see why I will use a DMA function in a driver without DMA support.
Perhaps I do not know some tricks.
Can I use writel/readl on address gived by DMA API ?

[...]

quoted

+EXPORT_SYMBOL_GPL(sunxi_aes_poll);

Again, don't export the symbol please.

[...]

quoted

diff --git a/drivers/crypto/sunxi-ss/sunxi-ss-cipher.h

b/drivers/crypto/sunxi-ss/sunxi-ss-cipher.h new file mode 100644
index 0000000..ecfbf9c

--- /dev/null
+++ b/drivers/crypto/sunxi-ss/sunxi-ss-cipher.h

@@ -0,0 +1,8 @@
+#include "sunxi-ss.h"
+
+extern struct sunxi_ss_ctx *ss;

Right. Please make it into one module and you won't need all this horror.
[...]

Thanks for your review

Regards