crypto: omap-aes - Add CTR algorithm Support

The OMAP3 and OMAP4/AM33xx versions of the AES crypto
module support the CTR algorithm in addition to ECB
and CBC that the OMAP2 version of the module supports.

So, OMAP2 and OMAP3 share a common register set but
OMAP3 supports CTR while OMAP2 doesn't.  OMAP4/AM33XX
uses a different register set from OMAP2/OMAP3 and
also supports CTR.

To add this support, use the platform_data introduced
in an ealier commit to hold the list of algorithms
supported by the current module.  The probe routine
will use that list to register the correct algorithms.

Note: The code being integrated is from the TI AM33xx SDK
and was written by Greg Turner <gkmturner@gmail.com> and
Herman Schuurman (current email unknown) while at TI.

CC: Greg Turner <gkmturner@gmail.com>
CC: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/omap-aes.c

@@ -48,7 +48,11 @@
 #define AES_REG_IV(dd, x)		((dd)->pdata->iv_ofs + ((x) * 0x04))
 
 #define AES_REG_CTRL(dd)		((dd)->pdata->ctrl_ofs)
-#define AES_REG_CTRL_CTR_WIDTH		(1 << 7)
+#define AES_REG_CTRL_CTR_WIDTH_MASK	(3 << 7)
+#define AES_REG_CTRL_CTR_WIDTH_32		(0 << 7)
+#define AES_REG_CTRL_CTR_WIDTH_64		(1 << 7)
+#define AES_REG_CTRL_CTR_WIDTH_96		(2 << 7)
+#define AES_REG_CTRL_CTR_WIDTH_128		(3 << 7)
 #define AES_REG_CTRL_CTR		(1 << 6)
 #define AES_REG_CTRL_CBC		(1 << 5)
 #define AES_REG_CTRL_KEY_SIZE		(3 << 3)
@@ -76,6 +80,7 @@
 #define FLAGS_ENCRYPT		BIT(0)
 #define FLAGS_CBC		BIT(1)
 #define FLAGS_GIV		BIT(2)
+#define FLAGS_CTR		BIT(3)
 
 #define FLAGS_INIT		BIT(4)
 #define FLAGS_FAST		BIT(5)
@@ -96,7 +101,16 @@ struct omap_aes_reqctx {
 #define OMAP_AES_QUEUE_LENGTH	1
 #define OMAP_AES_CACHE_SIZE	0
 
+struct omap_aes_algs_info {
+	struct crypto_alg	*algs_list;
+	unsigned int		size;
+	unsigned int		registered;
+};
+
 struct omap_aes_pdata {
+	struct omap_aes_algs_info	*algs_info;
+	unsigned int	algs_info_size;
+
 	void		(*trigger)(struct omap_aes_dev *dd, int length);
 
 	u32		key_ofs;
@@ -208,7 +222,7 @@ static int omap_aes_write_ctrl(struct omap_aes_dev *dd)
 {
 	unsigned int key32;
 	int i, err;
-	u32 val, mask;
+	u32 val, mask = 0;
 
 	err = omap_aes_hw_init(dd);
 	if (err)
@@ -222,16 +236,20 @@ static int omap_aes_write_ctrl(struct omap_aes_dev *dd)
 			__le32_to_cpu(dd->ctx->key[i]));
 	}
 
-	if ((dd->flags & FLAGS_CBC) && dd->req->info)
+	if ((dd->flags & (FLAGS_CBC | FLAGS_CTR)) && dd->req->info)
 		omap_aes_write_n(dd, AES_REG_IV(dd, 0), dd->req->info, 4);
 
 	val = FLD_VAL(((dd->ctx->keylen >> 3) - 1), 4, 3);
 	if (dd->flags & FLAGS_CBC)
 		val |= AES_REG_CTRL_CBC;
+	if (dd->flags & FLAGS_CTR) {
+		val |= AES_REG_CTRL_CTR | AES_REG_CTRL_CTR_WIDTH_32;
+		mask = AES_REG_CTRL_CTR | AES_REG_CTRL_CTR_WIDTH_MASK;
+	}
 	if (dd->flags & FLAGS_ENCRYPT)
 		val |= AES_REG_CTRL_DIRECTION;
 
-	mask = AES_REG_CTRL_CBC | AES_REG_CTRL_DIRECTION |
+	mask |= AES_REG_CTRL_CBC | AES_REG_CTRL_DIRECTION |
 			AES_REG_CTRL_KEY_SIZE;
 
 	omap_aes_write_mask(dd, AES_REG_CTRL(dd), val, mask);
@@ -807,6 +825,16 @@ static int omap_aes_cbc_decrypt(struct ablkcipher_request *req)
 	return omap_aes_crypt(req, FLAGS_CBC);
 }
 
+static int omap_aes_ctr_encrypt(struct ablkcipher_request *req)
+{
+	return omap_aes_crypt(req, FLAGS_ENCRYPT | FLAGS_CTR);
+}
+
+static int omap_aes_ctr_decrypt(struct ablkcipher_request *req)
+{
+	return omap_aes_crypt(req, FLAGS_CTR);
+}
+
 static int omap_aes_cra_init(struct crypto_tfm *tfm)
 {
 	pr_debug("enter\n");
@@ -823,7 +851,7 @@ static void omap_aes_cra_exit(struct crypto_tfm *tfm)
 
 /* ********************** ALGS ************************************ */
 
-static struct crypto_alg algs[] = {
+static struct crypto_alg algs_ecb_cbc[] = {
 {
 	.cra_name		= "ecb(aes)",
 	.cra_driver_name	= "ecb-aes-omap",
@@ -871,7 +899,43 @@ static struct crypto_alg algs[] = {
 }
 };
 
+static struct crypto_alg algs_ctr[] = {
+{
+	.cra_name		= "ctr(aes)",
+	.cra_driver_name	= "ctr-aes-omap",
+	.cra_priority		= 100,
+	.cra_flags		= CRYPTO_ALG_TYPE_ABLKCIPHER |
+				  CRYPTO_ALG_KERN_DRIVER_ONLY |
+				  CRYPTO_ALG_ASYNC,
+	.cra_blocksize		= AES_BLOCK_SIZE,
+	.cra_ctxsize		= sizeof(struct omap_aes_ctx),
+	.cra_alignmask		= 0,
+	.cra_type		= &crypto_ablkcipher_type,
+	.cra_module		= THIS_MODULE,
+	.cra_init		= omap_aes_cra_init,
+	.cra_exit		= omap_aes_cra_exit,
+	.cra_u.ablkcipher = {
+		.min_keysize	= AES_MIN_KEY_SIZE,
+		.max_keysize	= AES_MAX_KEY_SIZE,
+		.geniv		= "eseqiv",
+		.ivsize		= AES_BLOCK_SIZE,
+		.setkey		= omap_aes_setkey,
+		.encrypt	= omap_aes_ctr_encrypt,
+		.decrypt	= omap_aes_ctr_decrypt,
+	}
+} ,
+};
+
+static struct omap_aes_algs_info omap_aes_algs_info_ecb_cbc[] = {
+	{
+		.algs_list	= algs_ecb_cbc,
+		.size		= ARRAY_SIZE(algs_ecb_cbc),
+	},
+};
+
 static const struct omap_aes_pdata omap_aes_pdata_omap2 = {
+	.algs_info	= omap_aes_algs_info_ecb_cbc,
+	.algs_info_size	= ARRAY_SIZE(omap_aes_algs_info_ecb_cbc),
 	.trigger	= omap_aes_dma_trigger_omap2,
 	.key_ofs	= 0x1c,
 	.iv_ofs		= 0x20,
@@ -889,7 +953,39 @@ static const struct omap_aes_pdata omap_aes_pdata_omap2 = {
 };
 
 #ifdef CONFIG_OF
+static struct omap_aes_algs_info omap_aes_algs_info_ecb_cbc_ctr[] = {
+	{
+		.algs_list	= algs_ecb_cbc,
+		.size		= ARRAY_SIZE(algs_ecb_cbc),
+	},
+	{
+		.algs_list	= algs_ctr,
+		.size		= ARRAY_SIZE(algs_ctr),
+	},
+};
+
+static const struct omap_aes_pdata omap_aes_pdata_omap3 = {
+	.algs_info	= omap_aes_algs_info_ecb_cbc_ctr,
+	.algs_info_size	= ARRAY_SIZE(omap_aes_algs_info_ecb_cbc_ctr),
+	.trigger	= omap_aes_dma_trigger_omap2,
+	.key_ofs	= 0x1c,
+	.iv_ofs		= 0x20,
+	.ctrl_ofs	= 0x30,
+	.data_ofs	= 0x34,
+	.rev_ofs	= 0x44,
+	.mask_ofs	= 0x48,
+	.dma_enable_in	= BIT(2),
+	.dma_enable_out	= BIT(3),
+	.dma_start	= BIT(5),
+	.major_mask	= 0xf0,
+	.major_shift	= 4,
+	.minor_mask	= 0x0f,
+	.minor_shift	= 0,
+};
+
 static const struct omap_aes_pdata omap_aes_pdata_omap4 = {
+	.algs_info	= omap_aes_algs_info_ecb_cbc_ctr,
+	.algs_info_size	= ARRAY_SIZE(omap_aes_algs_info_ecb_cbc_ctr),
 	.trigger	= omap_aes_dma_trigger_omap4,
 	.key_ofs	= 0x3c,
 	.iv_ofs		= 0x40,
@@ -910,6 +1006,10 @@ static const struct of_device_id omap_aes_of_match[] = {
 		.compatible	= "ti,omap2-aes",
 		.data		= &omap_aes_pdata_omap2,
 	},
+	{
+		.compatible	= "ti,omap3-aes",
+		.data		= &omap_aes_pdata_omap3,
+	},
 	{
 		.compatible	= "ti,omap4-aes",
 		.data		= &omap_aes_pdata_omap4,
@@ -1004,6 +1104,7 @@ static int omap_aes_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
 	struct omap_aes_dev *dd;
+	struct crypto_alg *algp;
 	struct resource res;
 	int err = -ENOMEM, i, j;
 	u32 reg;
@@ -1057,17 +1158,27 @@ static int omap_aes_probe(struct platform_device *pdev)
 	list_add_tail(&dd->list, &dev_list);
 	spin_unlock(&list_lock);
 
-	for (i = 0; i < ARRAY_SIZE(algs); i++) {
-		pr_debug("i: %d\n", i);
-		err = crypto_register_alg(&algs[i]);
+	for (i = 0; i < dd->pdata->algs_info_size; i++) {
+		for (j = 0; j < dd->pdata->algs_info[i].size; j++) {
+			algp = &dd->pdata->algs_info[i].algs_list[j];
+
+			pr_debug("reg alg: %s\n", algp->cra_name);
+			INIT_LIST_HEAD(&algp->cra_list);
+
+			err = crypto_register_alg(algp);
 			if (err)
 				goto err_algs;
+
+			dd->pdata->algs_info[i].registered++;
+		}
 	}
 
 	return 0;
 err_algs:
-	for (j = 0; j < i; j++)
-		crypto_unregister_alg(&algs[j]);
+	for (i = dd->pdata->algs_info_size - 1; i >= 0; i--)
+		for (j = dd->pdata->algs_info[i].registered - 1; j >= 0; j--)
+			crypto_unregister_alg(
+					&dd->pdata->algs_info[i].algs_list[j]);
 	omap_aes_dma_cleanup(dd);
 err_dma:
 	tasklet_kill(&dd->done_task);
@@ -1084,7 +1195,7 @@ static int omap_aes_probe(struct platform_device *pdev)
 static int omap_aes_remove(struct platform_device *pdev)
 {
 	struct omap_aes_dev *dd = platform_get_drvdata(pdev);
-	int i;
+	int i, j;
 
 	if (!dd)
 		return -ENODEV;
@@ -1093,8 +1204,10 @@ static int omap_aes_remove(struct platform_device *pdev)
 	list_del(&dd->list);
 	spin_unlock(&list_lock);
 
-	for (i = 0; i < ARRAY_SIZE(algs); i++)
-		crypto_unregister_alg(&algs[i]);
+	for (i = dd->pdata->algs_info_size - 1; i >= 0; i--)
+		for (j = dd->pdata->algs_info[i].registered - 1; j >= 0; j--)
+			crypto_unregister_alg(
+					&dd->pdata->algs_info[i].algs_list[j]);
 
 	tasklet_kill(&dd->done_task);
 	tasklet_kill(&dd->queue_task);