[PATCH v8 12/23] drivers: crypto: meson: add support for AES-CTR

[Alexey Romanov]

This patch adds support for AES-CTR algorithm.
Tested via tcrypt and custom tests.

Signed-off-by: Alexey Romanov <avromanov at salutedevices.com>
---
 drivers/crypto/amlogic/amlogic-gxl-cipher.c | 59 +++++++++++++++++++--
 drivers/crypto/amlogic/amlogic-gxl-core.c   |  1 +
 drivers/crypto/amlogic/amlogic-gxl.h        |  2 +
 3 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/drivers/crypto/amlogic/amlogic-gxl-cipher.c b/drivers/crypto/amlogic/amlogic-gxl-cipher.c
index 622e179320ff..5c5956a18744 100644
--- a/drivers/crypto/amlogic/amlogic-gxl-cipher.c
+++ b/drivers/crypto/amlogic/amlogic-gxl-cipher.c
@@ -139,6 +139,15 @@ static void meson_unmap_scatterlist(struct skcipher_request *areq, struct meson_
 	}
 }
 
+static void reverse_keyiv(u32 *keyiv, u32 *iv)
+{
+	int size = AES_BLOCK_SIZE / sizeof(u32);
+	int i;
+
+	for (i = 0; i < size; i++)
+		*(keyiv + size - i - 1) = cpu_to_be32(*(iv + i));
+}
+
 static void meson_setup_keyiv_descs(struct cipher_ctx *ctx)
 {
 	struct meson_cipher_req_ctx *rctx = skcipher_request_ctx(ctx->areq);
@@ -155,8 +164,12 @@ static void meson_setup_keyiv_descs(struct cipher_ctx *ctx)
 	if (ctx->tloffset)
 		return;
 
-	if (blockmode == DESC_OPMODE_CBC) {
-		memcpy(op->keyiv + AES_MAX_KEY_SIZE, ctx->areq->iv, ivsize);
+	if (blockmode == DESC_OPMODE_CBC || blockmode == DESC_OPMODE_CTR) {
+		if (blockmode == DESC_OPMODE_CTR && mc->pdata->reverse_keyiv)
+			reverse_keyiv((u32 *)(op->keyiv + AES_MAX_KEY_SIZE), (u32 *)ctx->areq->iv);
+		else
+			memcpy(op->keyiv + AES_MAX_KEY_SIZE, ctx->areq->iv, ivsize);
+
 		dma_sync_single_for_device(mc->dev, ctx->keyiv.addr,
 					   ctx->keyiv.len, DMA_TO_DEVICE);
 	}
@@ -187,6 +200,7 @@ static bool meson_setup_data_descs(struct cipher_ctx *ctx)
 	struct meson_desc *desc = &mc->chanlist[rctx->flow].tl[ctx->tloffset];
 	unsigned int blocksize = crypto_skcipher_blocksize(tfm);
 	unsigned int blockmode = algt->blockmode;
+	unsigned int ivsize = crypto_skcipher_ivsize(tfm);
 	unsigned int maxlen = rounddown(DESC_MAXLEN, blocksize);
 	unsigned int todo;
 	u32 v;
@@ -205,8 +219,15 @@ static bool meson_setup_data_descs(struct cipher_ctx *ctx)
 	ctx->src_offset += todo;
 	ctx->dst_offset += todo;
 
+	if (blockmode == DESC_OPMODE_CTR) {
+		unsigned int nblocks = todo / blocksize;
+
+		while (nblocks--)
+			crypto_inc(ctx->areq->iv, ivsize);
+	}
+
 	v = DESC_OWN | blockmode | op->keymode | todo;
-	if (rctx->op_dir == MESON_ENCRYPT)
+	if (rctx->op_dir == MESON_ENCRYPT || blockmode == DESC_OPMODE_CTR)
 		v |= DESC_ENCRYPTION;
 
 	if (!ctx->cryptlen || ctx->tloffset == MAXDESC)
@@ -326,7 +347,8 @@ static int meson_cipher(struct skcipher_request *areq)
 	if (ctx.keyiv.len == AES_KEYSIZE_192)
 		ctx.keyiv.len = AES_MAX_KEY_SIZE;
 
-	if (algt->blockmode == DESC_OPMODE_CBC) {
+	if (algt->blockmode == DESC_OPMODE_CBC ||
+	    algt->blockmode == DESC_OPMODE_CTR) {
 		memcpy(op->keyiv + AES_MAX_KEY_SIZE, areq->iv, ivsize);
 		ctx.keyiv.len = AES_MAX_KEY_SIZE + ivsize;
 	}
@@ -540,6 +562,35 @@ static struct meson_alg_template algs[] = {
 		.do_one_request = meson_handle_cipher_request,
 	},
 },
+{
+	.type = CRYPTO_ALG_TYPE_SKCIPHER,
+	.blockmode = DESC_OPMODE_CTR,
+	.alg.skcipher.base = {
+		.base = {
+			.cra_name = "ctr(aes)",
+			.cra_driver_name = "ctr-aes-gxl",
+			.cra_priority = 400,
+			.cra_blocksize = AES_BLOCK_SIZE,
+			.cra_flags = CRYPTO_ALG_TYPE_SKCIPHER |
+				CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY |
+				CRYPTO_ALG_NEED_FALLBACK,
+			.cra_ctxsize = sizeof(struct meson_cipher_tfm_ctx) + CRYPTO_DMA_PADDING,
+			.cra_module = THIS_MODULE,
+			.cra_alignmask = 0xf,
+			.cra_init = meson_cipher_init,
+			.cra_exit = meson_cipher_exit,
+		},
+		.min_keysize	= AES_MIN_KEY_SIZE,
+		.max_keysize	= AES_MAX_KEY_SIZE,
+		.ivsize		= AES_BLOCK_SIZE,
+		.setkey		= meson_aes_setkey,
+		.encrypt	= meson_skencrypt,
+		.decrypt	= meson_skdecrypt,
+	},
+	.alg.skcipher.op = {
+		.do_one_request = meson_handle_cipher_request,
+	},
+},
 };
 
 int meson_cipher_register(struct meson_dev *mc)
diff --git a/drivers/crypto/amlogic/amlogic-gxl-core.c b/drivers/crypto/amlogic/amlogic-gxl-core.c
index a1aff009f913..2c8387906655 100644
--- a/drivers/crypto/amlogic/amlogic-gxl-core.c
+++ b/drivers/crypto/amlogic/amlogic-gxl-core.c
@@ -282,6 +282,7 @@ static const struct meson_pdata meson_gxl_pdata = {
 	.status_reg = 0x4,
 	.setup_desc_cnt = 3,
 	.hasher_supported = false,
+	.reverse_keyiv = true,
 };
 
 static const struct of_device_id meson_crypto_of_match_table[] = {
diff --git a/drivers/crypto/amlogic/amlogic-gxl.h b/drivers/crypto/amlogic/amlogic-gxl.h
index cebdfd81f6e2..de11e174f03d 100644
--- a/drivers/crypto/amlogic/amlogic-gxl.h
+++ b/drivers/crypto/amlogic/amlogic-gxl.h
@@ -24,6 +24,7 @@
 
 #define DESC_OPMODE_ECB (0 << 26)
 #define DESC_OPMODE_CBC (1 << 26)
+#define DESC_OPMODE_CTR (2 << 26)
 #define DESC_OPMODE_SHA (0 << 26)
 
 #define DESC_MAXLEN GENMASK(16, 0)
@@ -103,6 +104,7 @@ struct meson_pdata {
 	u32 status_reg;
 	u32 setup_desc_cnt;
 	bool hasher_supported;
+	bool reverse_keyiv;
 };
 
 /*
-- 
2.34.1