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// SPDX-License-Identifier: GPL-2.0
/*
* Xilinx ZynqMP AES Driver.
* Copyright (c) 2020 Xilinx Inc.
*/
#include <crypto/aes.h>
#include <crypto/engine.h>
#include <crypto/gcm.h>
#include <crypto/internal/aead.h>
#include <crypto/scatterwalk.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/firmware/xlnx-zynqmp.h>
#define ZYNQMP_DMA_BIT_MASK 32U
#define ZYNQMP_AES_KEY_SIZE AES_KEYSIZE_256
#define ZYNQMP_AES_AUTH_SIZE 16U
#define ZYNQMP_KEY_SRC_SEL_KEY_LEN 1U
#define ZYNQMP_AES_BLK_SIZE 1U
#define ZYNQMP_AES_MIN_INPUT_BLK_SIZE 4U
#define ZYNQMP_AES_WORD_LEN 4U
#define ZYNQMP_AES_GCM_TAG_MISMATCH_ERR 0x01
#define ZYNQMP_AES_WRONG_KEY_SRC_ERR 0x13
#define ZYNQMP_AES_PUF_NOT_PROGRAMMED 0xE300
enum zynqmp_aead_op {
ZYNQMP_AES_DECRYPT = 0,
ZYNQMP_AES_ENCRYPT
};
enum zynqmp_aead_keysrc {
ZYNQMP_AES_KUP_KEY = 0,
ZYNQMP_AES_DEV_KEY,
ZYNQMP_AES_PUF_KEY
};
struct zynqmp_aead_drv_ctx {
union {
struct aead_alg aead;
} alg;
struct device *dev;
struct crypto_engine *engine;
};
struct zynqmp_aead_hw_req {
u64 src;
u64 iv;
u64 key;
u64 dst;
u64 size;
u64 op;
u64 keysrc;
};
struct zynqmp_aead_tfm_ctx {
struct crypto_engine_ctx engine_ctx;
struct device *dev;
u8 key[ZYNQMP_AES_KEY_SIZE];
u8 *iv;
u32 keylen;
u32 authsize;
enum zynqmp_aead_keysrc keysrc;
struct crypto_aead *fbk_cipher;
};
struct zynqmp_aead_req_ctx {
enum zynqmp_aead_op op;
};
static int zynqmp_aes_aead_cipher(struct aead_request *req)
{
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct zynqmp_aead_tfm_ctx *tfm_ctx = crypto_aead_ctx(aead);
struct zynqmp_aead_req_ctx *rq_ctx = aead_request_ctx(req);
struct device *dev = tfm_ctx->dev;
struct zynqmp_aead_hw_req *hwreq;
dma_addr_t dma_addr_data, dma_addr_hw_req;
unsigned int data_size;
unsigned int status;
int ret;
size_t dma_size;
char *kbuf;
int err;
if (tfm_ctx->keysrc == ZYNQMP_AES_KUP_KEY)
dma_size = req->cryptlen + ZYNQMP_AES_KEY_SIZE
+ GCM_AES_IV_SIZE;
else
dma_size = req->cryptlen + GCM_AES_IV_SIZE;
kbuf = dma_alloc_coherent(dev, dma_size, &dma_addr_data, GFP_KERNEL);
if (!kbuf)
return -ENOMEM;
hwreq = dma_alloc_coherent(dev, sizeof(struct zynqmp_aead_hw_req),
&dma_addr_hw_req, GFP_KERNEL);
if (!hwreq) {
dma_free_coherent(dev, dma_size, kbuf, dma_addr_data);
return -ENOMEM;
}
data_size = req->cryptlen;
scatterwalk_map_and_copy(kbuf, req->src, 0, req->cryptlen, 0);
memcpy(kbuf + data_size, req->iv, GCM_AES_IV_SIZE);
hwreq->src = dma_addr_data;
hwreq->dst = dma_addr_data;
hwreq->iv = hwreq->src + data_size;
hwreq->keysrc = tfm_ctx->keysrc;
hwreq->op = rq_ctx->op;
if (hwreq->op == ZYNQMP_AES_ENCRYPT)
hwreq->size = data_size;
else
hwreq->size = data_size - ZYNQMP_AES_AUTH_SIZE;
if (hwreq->keysrc == ZYNQMP_AES_KUP_KEY) {
memcpy(kbuf + data_size + GCM_AES_IV_SIZE,
tfm_ctx->key, ZYNQMP_AES_KEY_SIZE);
hwreq->key = hwreq->src + data_size + GCM_AES_IV_SIZE;
} else {
hwreq->key = 0;
}
ret = zynqmp_pm_aes_engine(dma_addr_hw_req, &status);
if (ret) {
dev_err(dev, "ERROR: AES PM API failed\n");
err = ret;
} else if (status) {
switch (status) {
case ZYNQMP_AES_GCM_TAG_MISMATCH_ERR:
dev_err(dev, "ERROR: Gcm Tag mismatch\n");
break;
case ZYNQMP_AES_WRONG_KEY_SRC_ERR:
dev_err(dev, "ERROR: Wrong KeySrc, enable secure mode\n");
break;
case ZYNQMP_AES_PUF_NOT_PROGRAMMED:
dev_err(dev, "ERROR: PUF is not registered\n");
break;
default:
dev_err(dev, "ERROR: Unknown error\n");
break;
}
err = -status;
} else {
if (hwreq->op == ZYNQMP_AES_ENCRYPT)
data_size = data_size + ZYNQMP_AES_AUTH_SIZE;
else
data_size = data_size - ZYNQMP_AES_AUTH_SIZE;
sg_copy_from_buffer(req->dst, sg_nents(req->dst),
kbuf, data_size);
err = 0;
}
if (kbuf) {
memzero_explicit(kbuf, dma_size);
dma_free_coherent(dev, dma_size, kbuf, dma_addr_data);
}
if (hwreq) {
memzero_explicit(hwreq, sizeof(struct zynqmp_aead_hw_req));
dma_free_coherent(dev, sizeof(struct zynqmp_aead_hw_req),
hwreq, dma_addr_hw_req);
}
return err;
}
static int zynqmp_fallback_check(struct zynqmp_aead_tfm_ctx *tfm_ctx,
struct aead_request *req)
{
int need_fallback = 0;
struct zynqmp_aead_req_ctx *rq_ctx = aead_request_ctx(req);
if (tfm_ctx->authsize != ZYNQMP_AES_AUTH_SIZE)
need_fallback = 1;
if (tfm_ctx->keysrc == ZYNQMP_AES_KUP_KEY &&
tfm_ctx->keylen != ZYNQMP_AES_KEY_SIZE) {
need_fallback = 1;
}
if (req->assoclen != 0 ||
req->cryptlen < ZYNQMP_AES_MIN_INPUT_BLK_SIZE) {
need_fallback = 1;
}
if ((req->cryptlen % ZYNQMP_AES_WORD_LEN) != 0)
need_fallback = 1;
if (rq_ctx->op == ZYNQMP_AES_DECRYPT &&
req->cryptlen <= ZYNQMP_AES_AUTH_SIZE) {
need_fallback = 1;
}
return need_fallback;
}
static int zynqmp_handle_aes_req(struct crypto_engine *engine,
void *req)
{
struct aead_request *areq =
container_of(req, struct aead_request, base);
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct zynqmp_aead_tfm_ctx *tfm_ctx = crypto_aead_ctx(aead);
struct zynqmp_aead_req_ctx *rq_ctx = aead_request_ctx(areq);
struct aead_request *subreq = aead_request_ctx(req);
int need_fallback;
int err;
need_fallback = zynqmp_fallback_check(tfm_ctx, areq);
if (need_fallback) {
aead_request_set_tfm(subreq, tfm_ctx->fbk_cipher);
aead_request_set_callback(subreq, areq->base.flags,
NULL, NULL);
aead_request_set_crypt(subreq, areq->src, areq->dst,
areq->cryptlen, areq->iv);
aead_request_set_ad(subreq, areq->assoclen);
if (rq_ctx->op == ZYNQMP_AES_ENCRYPT)
err = crypto_aead_encrypt(subreq);
else
err = crypto_aead_decrypt(subreq);
} else {
err = zynqmp_aes_aead_cipher(areq);
}
crypto_finalize_aead_request(engine, areq, err);
return 0;
}
static int zynqmp_aes_aead_setkey(struct crypto_aead *aead, const u8 *key,
unsigned int keylen)
{
struct crypto_tfm *tfm = crypto_aead_tfm(aead);
struct zynqmp_aead_tfm_ctx *tfm_ctx =
(struct zynqmp_aead_tfm_ctx *)crypto_tfm_ctx(tfm);
unsigned char keysrc;
if (keylen == ZYNQMP_KEY_SRC_SEL_KEY_LEN) {
keysrc = *key;
if (keysrc == ZYNQMP_AES_KUP_KEY ||
keysrc == ZYNQMP_AES_DEV_KEY ||
keysrc == ZYNQMP_AES_PUF_KEY) {
tfm_ctx->keysrc = (enum zynqmp_aead_keysrc)keysrc;
} else {
tfm_ctx->keylen = keylen;
}
} else {
tfm_ctx->keylen = keylen;
if (keylen == ZYNQMP_AES_KEY_SIZE) {
tfm_ctx->keysrc = ZYNQMP_AES_KUP_KEY;
memcpy(tfm_ctx->key, key, keylen);
}
}
tfm_ctx->fbk_cipher->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
tfm_ctx->fbk_cipher->base.crt_flags |= (aead->base.crt_flags &
CRYPTO_TFM_REQ_MASK);
return crypto_aead_setkey(tfm_ctx->fbk_cipher, key, keylen);
}
static int zynqmp_aes_aead_setauthsize(struct crypto_aead *aead,
unsigned int authsize)
{
struct crypto_tfm *tfm = crypto_aead_tfm(aead);
struct zynqmp_aead_tfm_ctx *tfm_ctx =
(struct zynqmp_aead_tfm_ctx *)crypto_tfm_ctx(tfm);
tfm_ctx->authsize = authsize;
return crypto_aead_setauthsize(tfm_ctx->fbk_cipher, authsize);
}
static int zynqmp_aes_aead_encrypt(struct aead_request *req)
{
struct zynqmp_aead_drv_ctx *drv_ctx;
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct aead_alg *alg = crypto_aead_alg(aead);
struct zynqmp_aead_req_ctx *rq_ctx = aead_request_ctx(req);
rq_ctx->op = ZYNQMP_AES_ENCRYPT;
drv_ctx = container_of(alg, struct zynqmp_aead_drv_ctx, alg.aead);
return crypto_transfer_aead_request_to_engine(drv_ctx->engine, req);
}
static int zynqmp_aes_aead_decrypt(struct aead_request *req)
{
struct zynqmp_aead_drv_ctx *drv_ctx;
struct crypto_aead *aead = crypto_aead_reqtfm(req);
struct aead_alg *alg = crypto_aead_alg(aead);
struct zynqmp_aead_req_ctx *rq_ctx = aead_request_ctx(req);
rq_ctx->op = ZYNQMP_AES_DECRYPT;
drv_ctx = container_of(alg, struct zynqmp_aead_drv_ctx, alg.aead);
return crypto_transfer_aead_request_to_engine(drv_ctx->engine, req);
}
static int zynqmp_aes_aead_init(struct crypto_aead *aead)
{
struct crypto_tfm *tfm = crypto_aead_tfm(aead);
struct zynqmp_aead_tfm_ctx *tfm_ctx =
(struct zynqmp_aead_tfm_ctx *)crypto_tfm_ctx(tfm);
struct zynqmp_aead_drv_ctx *drv_ctx;
struct aead_alg *alg = crypto_aead_alg(aead);
drv_ctx = container_of(alg, struct zynqmp_aead_drv_ctx, alg.aead);
tfm_ctx->dev = drv_ctx->dev;
tfm_ctx->engine_ctx.op.do_one_request = zynqmp_handle_aes_req;
tfm_ctx->engine_ctx.op.prepare_request = NULL;
tfm_ctx->engine_ctx.op.unprepare_request = NULL;
tfm_ctx->fbk_cipher = crypto_alloc_aead(drv_ctx->alg.aead.base.cra_name,
0,
CRYPTO_ALG_NEED_FALLBACK);
if (IS_ERR(tfm_ctx->fbk_cipher)) {
pr_err("%s() Error: failed to allocate fallback for %s\n",
__func__, drv_ctx->alg.aead.base.cra_name);
return PTR_ERR(tfm_ctx->fbk_cipher);
}
crypto_aead_set_reqsize(aead,
max(sizeof(struct zynqmp_aead_req_ctx),
sizeof(struct aead_request) +
crypto_aead_reqsize(tfm_ctx->fbk_cipher)));
return 0;
}
static void zynqmp_aes_aead_exit(struct crypto_aead *aead)
{
struct crypto_tfm *tfm = crypto_aead_tfm(aead);
struct zynqmp_aead_tfm_ctx *tfm_ctx =
(struct zynqmp_aead_tfm_ctx *)crypto_tfm_ctx(tfm);
if (tfm_ctx->fbk_cipher) {
crypto_free_aead(tfm_ctx->fbk_cipher);
tfm_ctx->fbk_cipher = NULL;
}
memzero_explicit(tfm_ctx, sizeof(struct zynqmp_aead_tfm_ctx));
}
static struct zynqmp_aead_drv_ctx aes_drv_ctx = {
.alg.aead = {
.setkey = zynqmp_aes_aead_setkey,
.setauthsize = zynqmp_aes_aead_setauthsize,
.encrypt = zynqmp_aes_aead_encrypt,
.decrypt = zynqmp_aes_aead_decrypt,
.init = zynqmp_aes_aead_init,
.exit = zynqmp_aes_aead_exit,
.ivsize = GCM_AES_IV_SIZE,
.maxauthsize = ZYNQMP_AES_AUTH_SIZE,
.base = {
.cra_name = "gcm(aes)",
.cra_driver_name = "xilinx-zynqmp-aes-gcm",
.cra_priority = 200,
.cra_flags = CRYPTO_ALG_TYPE_AEAD |
CRYPTO_ALG_ASYNC |
CRYPTO_ALG_ALLOCATES_MEMORY |
CRYPTO_ALG_KERN_DRIVER_ONLY |
CRYPTO_ALG_NEED_FALLBACK,
.cra_blocksize = ZYNQMP_AES_BLK_SIZE,
.cra_ctxsize = sizeof(struct zynqmp_aead_tfm_ctx),
.cra_module = THIS_MODULE,
}
}
};
static int zynqmp_aes_aead_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
int err;
/* ZynqMP AES driver supports only one instance */
if (!aes_drv_ctx.dev)
aes_drv_ctx.dev = dev;
else
return -ENODEV;
err = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(ZYNQMP_DMA_BIT_MASK));
if (err < 0) {
dev_err(dev, "No usable DMA configuration\n");
return err;
}
aes_drv_ctx.engine = crypto_engine_alloc_init(dev, 1);
if (!aes_drv_ctx.engine) {
dev_err(dev, "Cannot alloc AES engine\n");
err = -ENOMEM;
goto err_engine;
}
err = crypto_engine_start(aes_drv_ctx.engine);
if (err) {
dev_err(dev, "Cannot start AES engine\n");
goto err_engine;
}
err = crypto_register_aead(&aes_drv_ctx.alg.aead);
if (err < 0) {
dev_err(dev, "Failed to register AEAD alg.\n");
goto err_aead;
}
return 0;
err_aead:
crypto_unregister_aead(&aes_drv_ctx.alg.aead);
err_engine:
if (aes_drv_ctx.engine)
crypto_engine_exit(aes_drv_ctx.engine);
return err;
}
static int zynqmp_aes_aead_remove(struct platform_device *pdev)
{
crypto_engine_exit(aes_drv_ctx.engine);
crypto_unregister_aead(&aes_drv_ctx.alg.aead);
return 0;
}
static const struct of_device_id zynqmp_aes_dt_ids[] = {
{ .compatible = "xlnx,zynqmp-aes" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, zynqmp_aes_dt_ids);
static struct platform_driver zynqmp_aes_driver = {
.probe = zynqmp_aes_aead_probe,
.remove = zynqmp_aes_aead_remove,
.driver = {
.name = "zynqmp-aes",
.of_match_table = zynqmp_aes_dt_ids,
},
};
module_platform_driver(zynqmp_aes_driver);
MODULE_LICENSE("GPL");