Add support for CTR mode of operation for AES algorithm in the AES
Engine of the DTHEv2 hardware cryptographic engine.
Signed-off-by: T Pratham <t-pratham@xxxxxx>
---
drivers/crypto/ti/Kconfig | 1 +
drivers/crypto/ti/dthev2-aes.c | 80 +++++++++++++++++++++++++++++--
drivers/crypto/ti/dthev2-common.c | 19 ++++++++
drivers/crypto/ti/dthev2-common.h | 15 ++++++
4 files changed, 110 insertions(+), 5 deletions(-)
diff --git a/drivers/crypto/ti/Kconfig b/drivers/crypto/ti/Kconfig
index bdb7f652e093..b36733a8c734 100644
--- a/drivers/crypto/ti/Kconfig
+++ b/drivers/crypto/ti/Kconfig
@@ -6,6 +6,7 @@ config CRYPTO_DEV_TI_DTHEV2
select CRYPTO_SKCIPHER
select CRYPTO_ECB
select CRYPTO_CBC
+ select CRYPTO_CTR
select CRYPTO_XTS
help
This enables support for the TI DTHE V2 hw cryptography engine
diff --git a/drivers/crypto/ti/dthev2-aes.c b/drivers/crypto/ti/dthev2-aes.c
index 21e7e5b8d6da..07787f0ae4fd 100644
--- a/drivers/crypto/ti/dthev2-aes.c
+++ b/drivers/crypto/ti/dthev2-aes.c
@@ -63,6 +63,7 @@
enum aes_ctrl_mode_masks {
AES_CTRL_ECB_MASK = 0x00,
AES_CTRL_CBC_MASK = BIT(5),
+ AES_CTRL_CTR_MASK = BIT(6),
AES_CTRL_XTS_MASK = BIT(12) | BIT(11),
};
@@ -74,6 +75,8 @@ enum aes_ctrl_mode_masks {
#define DTHE_AES_CTRL_KEYSIZE_24B BIT(4)
#define DTHE_AES_CTRL_KEYSIZE_32B (BIT(3) | BIT(4))
+#define DTHE_AES_CTRL_CTR_WIDTH_128B (BIT(7) | BIT(8))
+
#define DTHE_AES_CTRL_SAVE_CTX_SET BIT(29)
#define DTHE_AES_CTRL_OUTPUT_READY BIT_MASK(0)
@@ -131,6 +134,15 @@ static int dthe_aes_cbc_setkey(struct crypto_skcipher *tfm, const u8 *key, unsig
return dthe_aes_setkey(tfm, key, keylen);
}
+static int dthe_aes_ctr_setkey(struct crypto_skcipher *tfm, const u8 *key, unsigned int keylen)
+{
+ struct dthe_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
+
+ ctx->aes_mode = DTHE_AES_CTR;
+
+ return dthe_aes_setkey(tfm, key, keylen);
+}
+
static int dthe_aes_xts_setkey(struct crypto_skcipher *tfm, const u8 *key, unsigned int keylen)
{
struct dthe_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
@@ -206,6 +218,10 @@ static void dthe_aes_set_ctrl_key(struct dthe_tfm_ctx *ctx,
case DTHE_AES_CBC:
ctrl_val |= AES_CTRL_CBC_MASK;
break;
+ case DTHE_AES_CTR:
+ ctrl_val |= AES_CTRL_CTR_MASK;
+ ctrl_val |= DTHE_AES_CTRL_CTR_WIDTH_128B;
+ break;
case DTHE_AES_XTS:
ctrl_val |= AES_CTRL_XTS_MASK;
break;
@@ -246,6 +262,9 @@ static int dthe_aes_run(struct crypto_engine *engine, void *areq)
int src_mapped_nents;
int dst_mapped_nents;
+ u8 pad_buf[AES_BLOCK_SIZE] = {0};
+ int pad_len = 0;
+
bool diff_dst;
enum dma_data_direction src_dir, dst_dir;
@@ -265,6 +284,29 @@ static int dthe_aes_run(struct crypto_engine *engine, void *areq)
aes_irqenable_val |= DTHE_AES_IRQENABLE_EN_ALL;
writel_relaxed(aes_irqenable_val, aes_base_reg + DTHE_P_AES_IRQENABLE);
+ if (ctx->aes_mode == DTHE_AES_CTR) {
+ /*
+ * CTR mode can operate on any input length, but the hardware
+ * requires input length to be a multiple of the block size.
+ * We need to handle the padding in the driver.
+ */
+ if (req->cryptlen % AES_BLOCK_SIZE) {
+ /* Need to create a new SG list with padding */
+ pad_len = ALIGN(req->cryptlen, AES_BLOCK_SIZE) - req->cryptlen;
+ struct scatterlist *sg;
+
+ src = kmalloc_array((src_nents + 1), sizeof(*src), GFP_KERNEL);
+ if (!src) {
+ ret = -ENOMEM;
+ goto aes_alloc_err;
+ }
+ sg_init_table(src, src_nents + 1);
+ sg = dthe_copy_sg(src, req->src, req->cryptlen);
+ sg_set_buf(sg, pad_buf, pad_len);
+ src_nents++;
+ }
+ }
+
if (src == dst) {
diff_dst = false;
src_dir = DMA_BIDIRECTIONAL;
@@ -281,7 +323,7 @@ static int dthe_aes_run(struct crypto_engine *engine, void *areq)
src_mapped_nents = dma_map_sg(tx_dev, src, src_nents, src_dir);
if (src_mapped_nents == 0) {
ret = -EINVAL;
- goto aes_err;
+ goto aes_map_src_err;
}
if (!diff_dst) {
@@ -293,7 +335,7 @@ static int dthe_aes_run(struct crypto_engine *engine, void *areq)
if (dst_mapped_nents == 0) {
dma_unmap_sg(tx_dev, src, src_nents, src_dir);
ret = -EINVAL;
- goto aes_err;
+ goto aes_map_dst_err;
}
}
@@ -356,11 +398,16 @@ static int dthe_aes_run(struct crypto_engine *engine, void *areq)
}
aes_prep_err:
- dma_unmap_sg(tx_dev, src, src_nents, src_dir);
if (dst_dir != DMA_BIDIRECTIONAL)
dma_unmap_sg(rx_dev, dst, dst_nents, dst_dir);
+aes_map_dst_err:
+ dma_unmap_sg(tx_dev, src, src_nents, src_dir);
-aes_err:
+aes_map_src_err:
+ if (ctx->aes_mode == DTHE_AES_CTR && req->cryptlen % AES_BLOCK_SIZE)
+ kfree(src);
+
+aes_alloc_err:
local_bh_disable();
crypto_finalize_skcipher_request(dev_data->engine, req, ret);
local_bh_enable();
@@ -375,9 +422,10 @@ static int dthe_aes_crypt(struct skcipher_request *req)
/*
* If data is not a multiple of AES_BLOCK_SIZE, need to return -EINVAL
+ * except in CTR mode, where any length is supported.
* If data length input is zero, no need to do any operation.
*/
- if (req->cryptlen % AES_BLOCK_SIZE)
+ if (req->cryptlen % AES_BLOCK_SIZE && ctx->aes_mode != DTHE_AES_CTR)
return -EINVAL;
if (req->cryptlen == 0)
@@ -447,6 +495,28 @@ static struct skcipher_engine_alg cipher_algs[] = {
},
.op.do_one_request = dthe_aes_run,
}, /* CBC AES */
+ {
+ .base.init = dthe_cipher_init_tfm,
+ .base.setkey = dthe_aes_ctr_setkey,
+ .base.encrypt = dthe_aes_encrypt,
+ .base.decrypt = dthe_aes_decrypt,
+ .base.min_keysize = AES_MIN_KEY_SIZE,
+ .base.max_keysize = AES_MAX_KEY_SIZE,
+ .base.ivsize = AES_IV_SIZE,
+ .base.base = {
+ .cra_name = "ctr(aes)",
+ .cra_driver_name = "ctr-aes-dthev2",
+ .cra_priority = 299,
+ .cra_flags = CRYPTO_ALG_TYPE_SKCIPHER |
+ CRYPTO_ALG_KERN_DRIVER_ONLY,
+ .cra_alignmask = AES_BLOCK_SIZE - 1,
+ .cra_blocksize = 1,
+ .cra_ctxsize = sizeof(struct dthe_tfm_ctx),
+ .cra_reqsize = sizeof(struct dthe_aes_req_ctx),
+ .cra_module = THIS_MODULE,
+ },
+ .op.do_one_request = dthe_aes_run,
+ }, /* CTR AES */
{
.base.init = dthe_cipher_init_tfm,
.base.setkey = dthe_aes_xts_setkey,
diff --git a/drivers/crypto/ti/dthev2-common.c b/drivers/crypto/ti/dthev2-common.c
index c39d37933b9e..a2ad79bec105 100644
--- a/drivers/crypto/ti/dthev2-common.c
+++ b/drivers/crypto/ti/dthev2-common.c
@@ -48,6 +48,25 @@ struct dthe_data *dthe_get_dev(struct dthe_tfm_ctx *ctx)
return dev_data;
}
+struct scatterlist *dthe_copy_sg(struct scatterlist *dst,
+ struct scatterlist *src,
+ int buflen)
+{
+ struct scatterlist *from_sg, *to_sg;
+ int sglen;
+
+ for (to_sg = dst, from_sg = src; buflen && from_sg; buflen -= sglen) {
+ sglen = from_sg->length;
+ if (sglen > buflen)
+ sglen = buflen;
+ sg_set_buf(to_sg, sg_virt(from_sg), sglen);
+ from_sg = sg_next(from_sg);
+ to_sg = sg_next(to_sg);
+ }
+
+ return to_sg;
+}
+
static int dthe_dma_init(struct dthe_data *dev_data)
{
int ret;
diff --git a/drivers/crypto/ti/dthev2-common.h b/drivers/crypto/ti/dthev2-common.h
index e2d901e70fcc..629f45a3ab33 100644
--- a/drivers/crypto/ti/dthev2-common.h
+++ b/drivers/crypto/ti/dthev2-common.h
@@ -36,6 +36,7 @@
enum dthe_aes_mode {
DTHE_AES_ECB = 0,
DTHE_AES_CBC,
+ DTHE_AES_CTR,
DTHE_AES_XTS,
};
@@ -101,6 +102,20 @@ struct dthe_aes_req_ctx {
struct dthe_data *dthe_get_dev(struct dthe_tfm_ctx *ctx);
+/**
+ * dthe_copy_sg - Copy sg entries from src to dst
+ * @dst: Destination sg to be filled
+ * @src: Source sg to be copied from
+ * @buflen: Number of bytes to be copied
+ *
+ * Description:
+ * Copy buflen bytes of data from src to dst.
+ *
+ **/
+struct scatterlist *dthe_copy_sg(struct scatterlist *dst,
+ struct scatterlist *src,
+ int buflen);
+
int dthe_register_aes_algs(void);
void dthe_unregister_aes_algs(void);
--
2.43.0
