From: Andrei Botila <andrei.bot...@nxp.com>

A hardware limitation exists for CAAM until Era 9 which restricts
the accelerator to IVs with only 8 bytes. When CAAM has a lower era
a fallback is necessary to process 16 bytes IV.

Fixes: b189817cf789 ("crypto: caam/qi - add ablkcipher and authenc algorithms")
Cc: <sta...@vger.kernel.org> # v4.12+
Signed-off-by: Andrei Botila <andrei.bot...@nxp.com>
---
 drivers/crypto/caam/Kconfig      |  1 +
 drivers/crypto/caam/caamalg_qi.c | 70 +++++++++++++++++++++++++++++---
 2 files changed, 66 insertions(+), 5 deletions(-)

diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig
index dfeaad8dfe81..8169e6cd04e6 100644
--- a/drivers/crypto/caam/Kconfig
+++ b/drivers/crypto/caam/Kconfig
@@ -115,6 +115,7 @@ config CRYPTO_DEV_FSL_CAAM_CRYPTO_API_QI
        select CRYPTO_AUTHENC
        select CRYPTO_SKCIPHER
        select CRYPTO_DES
+       select CRYPTO_XTS
        help
          Selecting this will use CAAM Queue Interface (QI) for sending
          & receiving crypto jobs to/from CAAM. This gives better performance
diff --git a/drivers/crypto/caam/caamalg_qi.c b/drivers/crypto/caam/caamalg_qi.c
index bb1c0106a95c..2b5e694fdaf6 100644
--- a/drivers/crypto/caam/caamalg_qi.c
+++ b/drivers/crypto/caam/caamalg_qi.c
@@ -18,6 +18,7 @@
 #include "qi.h"
 #include "jr.h"
 #include "caamalg_desc.h"
+#include <asm/unaligned.h>
 
 /*
  * crypto alg
@@ -67,6 +68,11 @@ struct caam_ctx {
        struct device *qidev;
        spinlock_t lock;        /* Protects multiple init of driver context */
        struct caam_drv_ctx *drv_ctx[NUM_OP];
+       struct crypto_skcipher *fallback;
+};
+
+struct caam_skcipher_req_ctx {
+       struct skcipher_request fallback_req;
 };
 
 static int aead_set_sh_desc(struct crypto_aead *aead)
@@ -726,12 +732,17 @@ static int xts_skcipher_setkey(struct crypto_skcipher 
*skcipher, const u8 *key,
        struct caam_ctx *ctx = crypto_skcipher_ctx(skcipher);
        struct device *jrdev = ctx->jrdev;
        int ret = 0;
+       int err;
 
        if (keylen != 2 * AES_MIN_KEY_SIZE  && keylen != 2 * AES_MAX_KEY_SIZE) {
                dev_dbg(jrdev, "key size mismatch\n");
                return -EINVAL;
        }
 
+       err = crypto_skcipher_setkey(ctx->fallback, key, keylen);
+       if (err)
+               return err;
+
        ctx->cdata.keylen = keylen;
        ctx->cdata.key_virt = key;
        ctx->cdata.key_inline = true;
@@ -1373,6 +1384,17 @@ static struct skcipher_edesc 
*skcipher_edesc_alloc(struct skcipher_request *req,
        return edesc;
 }
 
+static bool xts_skcipher_ivsize(struct skcipher_request *req)
+{
+       struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
+       unsigned int ivsize = crypto_skcipher_ivsize(skcipher);
+       u64 size = 0;
+
+       size = get_unaligned((u64 *)(req->iv + (ivsize / 2)));
+
+       return !!size;
+}
+
 static inline int skcipher_crypt(struct skcipher_request *req, bool encrypt)
 {
        struct skcipher_edesc *edesc;
@@ -1383,6 +1405,21 @@ static inline int skcipher_crypt(struct skcipher_request 
*req, bool encrypt)
        if (!req->cryptlen)
                return 0;
 
+       if (ctx->fallback && xts_skcipher_ivsize(req)) {
+               struct caam_skcipher_req_ctx *rctx = skcipher_request_ctx(req);
+
+               skcipher_request_set_tfm(&rctx->fallback_req, ctx->fallback);
+               skcipher_request_set_callback(&rctx->fallback_req,
+                                             req->base.flags,
+                                             req->base.complete,
+                                             req->base.data);
+               skcipher_request_set_crypt(&rctx->fallback_req, req->src,
+                                          req->dst, req->cryptlen, req->iv);
+
+               return encrypt ? crypto_skcipher_encrypt(&rctx->fallback_req) :
+                                crypto_skcipher_decrypt(&rctx->fallback_req);
+       }
+
        if (unlikely(caam_congested))
                return -EAGAIN;
 
@@ -1507,6 +1544,7 @@ static struct caam_skcipher_alg driver_algs[] = {
                        .base = {
                                .cra_name = "xts(aes)",
                                .cra_driver_name = "xts-aes-caam-qi",
+                               .cra_flags = CRYPTO_ALG_NEED_FALLBACK,
                                .cra_blocksize = AES_BLOCK_SIZE,
                        },
                        .setkey = xts_skcipher_setkey,
@@ -2440,9 +2478,27 @@ static int caam_cra_init(struct crypto_skcipher *tfm)
        struct skcipher_alg *alg = crypto_skcipher_alg(tfm);
        struct caam_skcipher_alg *caam_alg =
                container_of(alg, typeof(*caam_alg), skcipher);
+       struct caam_ctx *ctx = crypto_skcipher_ctx(tfm);
+       u32 alg_aai = caam_alg->caam.class1_alg_type & OP_ALG_AAI_MASK;
+
+       if (alg_aai == OP_ALG_AAI_XTS) {
+               const char *tfm_name = crypto_tfm_alg_name(&tfm->base);
+               struct crypto_skcipher *fallback;
+
+               fallback = crypto_alloc_skcipher(tfm_name, 0,
+                                                CRYPTO_ALG_NEED_FALLBACK);
+               if (IS_ERR(fallback)) {
+                       dev_err(ctx->jrdev, "Failed to allocate %s fallback: 
%ld\n",
+                               tfm_name, PTR_ERR(fallback));
+                       return PTR_ERR(fallback);
+               }
 
-       return caam_init_common(crypto_skcipher_ctx(tfm), &caam_alg->caam,
-                               false);
+               ctx->fallback = fallback;
+               crypto_skcipher_set_reqsize(tfm, sizeof(struct 
caam_skcipher_req_ctx) +
+                                           crypto_skcipher_reqsize(fallback));
+       }
+
+       return caam_init_common(ctx, &caam_alg->caam, false);
 }
 
 static int caam_aead_init(struct crypto_aead *tfm)
@@ -2468,7 +2524,11 @@ static void caam_exit_common(struct caam_ctx *ctx)
 
 static void caam_cra_exit(struct crypto_skcipher *tfm)
 {
-       caam_exit_common(crypto_skcipher_ctx(tfm));
+       struct caam_ctx *ctx = crypto_skcipher_ctx(tfm);
+
+       if (ctx->fallback)
+               crypto_free_skcipher(ctx->fallback);
+       caam_exit_common(ctx);
 }
 
 static void caam_aead_exit(struct crypto_aead *tfm)
@@ -2502,8 +2562,8 @@ static void caam_skcipher_alg_init(struct 
caam_skcipher_alg *t_alg)
        alg->base.cra_module = THIS_MODULE;
        alg->base.cra_priority = CAAM_CRA_PRIORITY;
        alg->base.cra_ctxsize = sizeof(struct caam_ctx);
-       alg->base.cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY |
-                             CRYPTO_ALG_KERN_DRIVER_ONLY;
+       alg->base.cra_flags |= (CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY |
+                               CRYPTO_ALG_KERN_DRIVER_ONLY);
 
        alg->init = caam_cra_init;
        alg->exit = caam_cra_exit;
-- 
2.17.1

Reply via email to