crypto: caam/qi2 - add fallback for XTS with more than 8B IV

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: 226853ac3ebe ("crypto: caam/qi2 - add skcipher algorithms")
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Andrei Botila <andrei.botila@nxp.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/caam/Kconfig b/drivers/crypto/caam/Kconfig
index 8169e6c..84ea7cb 100644 (file)
--- a/drivers/crypto/caam/Kconfig
+++ b/drivers/crypto/caam/Kconfig
@@ -167,6 +167,7 @@ config CRYPTO_DEV_FSL_DPAA2_CAAM
        select CRYPTO_AEAD
        select CRYPTO_HASH
        select CRYPTO_DES
+       select CRYPTO_XTS
        help
          CAAM driver for QorIQ Data Path Acceleration Architecture 2.
          It handles DPSECI DPAA2 objects that sit on the Management Complex

diff --git a/drivers/crypto/caam/caamalg_qi2.c b/drivers/crypto/caam/caamalg_qi2.c
index 076c6b0..c36d118 100644 (file)
--- a/drivers/crypto/caam/caamalg_qi2.c
+++ b/drivers/crypto/caam/caamalg_qi2.c
@@ -19,6 +19,7 @@
 #include <linux/fsl/mc.h>
 #include <soc/fsl/dpaa2-io.h>
 #include <soc/fsl/dpaa2-fd.h>
+#include <asm/unaligned.h>
 
 #define CAAM_CRA_PRIORITY      2000
 
@@ -80,6 +81,7 @@ struct caam_ctx {
        struct alginfo adata;
        struct alginfo cdata;
        unsigned int authsize;
+       struct crypto_skcipher *fallback;
 };
 
 static void *dpaa2_caam_iova_to_virt(struct dpaa2_caam_priv *priv,
@@ -1056,12 +1058,17 @@ static int xts_skcipher_setkey(struct crypto_skcipher *skcipher, const u8 *key,
        struct device *dev = ctx->dev;
        struct caam_flc *flc;
        u32 *desc;
+       int err;
 
        if (keylen != 2 * AES_MIN_KEY_SIZE  && keylen != 2 * AES_MAX_KEY_SIZE) {
                dev_dbg(dev, "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;
@@ -1443,6 +1450,14 @@ static void skcipher_decrypt_done(void *cbk_ctx, u32 status)
        skcipher_request_complete(req, ecode);
 }
 
+static inline bool xts_skcipher_ivsize(struct skcipher_request *req)
+{
+       struct crypto_skcipher *skcipher = crypto_skcipher_reqtfm(req);
+       unsigned int ivsize = crypto_skcipher_ivsize(skcipher);
+
+       return !!get_unaligned((u64 *)(req->iv + (ivsize / 2)));
+}
+
 static int skcipher_encrypt(struct skcipher_request *req)
 {
        struct skcipher_edesc *edesc;
@@ -1454,6 +1469,18 @@ static int skcipher_encrypt(struct skcipher_request *req)
        if (!req->cryptlen)
                return 0;
 
+       if (ctx->fallback && xts_skcipher_ivsize(req)) {
+               skcipher_request_set_tfm(&caam_req->fallback_req, ctx->fallback);
+               skcipher_request_set_callback(&caam_req->fallback_req,
+                                             req->base.flags,
+                                             req->base.complete,
+                                             req->base.data);
+               skcipher_request_set_crypt(&caam_req->fallback_req, req->src,
+                                          req->dst, req->cryptlen, req->iv);
+
+               return crypto_skcipher_encrypt(&caam_req->fallback_req);
+       }
+
        /* allocate extended descriptor */
        edesc = skcipher_edesc_alloc(req);
        if (IS_ERR(edesc))
@@ -1484,6 +1511,19 @@ static int skcipher_decrypt(struct skcipher_request *req)
 
        if (!req->cryptlen)
                return 0;
+
+       if (ctx->fallback && xts_skcipher_ivsize(req)) {
+               skcipher_request_set_tfm(&caam_req->fallback_req, ctx->fallback);
+               skcipher_request_set_callback(&caam_req->fallback_req,
+                                             req->base.flags,
+                                             req->base.complete,
+                                             req->base.data);
+               skcipher_request_set_crypt(&caam_req->fallback_req, req->src,
+                                          req->dst, req->cryptlen, req->iv);
+
+               return crypto_skcipher_decrypt(&caam_req->fallback_req);
+       }
+
        /* allocate extended descriptor */
        edesc = skcipher_edesc_alloc(req);
        if (IS_ERR(edesc))
@@ -1537,9 +1577,34 @@ static int caam_cra_init_skcipher(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;
+       int ret = 0;
+
+       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->dev, "Failed to allocate %s fallback: %ld\n",
+                               tfm_name, PTR_ERR(fallback));
+                       return PTR_ERR(fallback);
+               }
+
+               ctx->fallback = fallback;
+               crypto_skcipher_set_reqsize(tfm, sizeof(struct caam_request) +
+                                           crypto_skcipher_reqsize(fallback));
+       } else {
+               crypto_skcipher_set_reqsize(tfm, sizeof(struct caam_request));
+       }
 
-       crypto_skcipher_set_reqsize(tfm, sizeof(struct caam_request));
-       return caam_cra_init(crypto_skcipher_ctx(tfm), &caam_alg->caam, false);
+       ret = caam_cra_init(ctx, &caam_alg->caam, false);
+       if (ret && ctx->fallback)
+               crypto_free_skcipher(ctx->fallback);
+
+       return ret;
 }
 
 static int caam_cra_init_aead(struct crypto_aead *tfm)
@@ -1562,7 +1627,11 @@ 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_cra_exit_aead(struct crypto_aead *tfm)
@@ -1665,6 +1734,7 @@ static struct caam_skcipher_alg driver_algs[] = {
                        .base = {
                                .cra_name = "xts(aes)",
                                .cra_driver_name = "xts-aes-caam-qi2",
+                               .cra_flags = CRYPTO_ALG_NEED_FALLBACK,
                                .cra_blocksize = AES_BLOCK_SIZE,
                        },
                        .setkey = xts_skcipher_setkey,
@@ -2912,8 +2982,8 @@ 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_skcipher;
        alg->exit = caam_cra_exit;

diff --git a/drivers/crypto/caam/caamalg_qi2.h b/drivers/crypto/caam/caamalg_qi2.h
index f29cb7b..d352534 100644 (file)
--- a/drivers/crypto/caam/caamalg_qi2.h
+++ b/drivers/crypto/caam/caamalg_qi2.h
@@ -13,6 +13,7 @@
 #include <linux/netdevice.h>
 #include "dpseci.h"
 #include "desc_constr.h"
+#include <crypto/skcipher.h>
 
 #define DPAA2_CAAM_STORE_SIZE  16
 /* NAPI weight *must* be a multiple of the store size. */
@@ -186,6 +187,7 @@ struct caam_request {
        void (*cbk)(void *ctx, u32 err);
        void *ctx;
        void *edesc;
+       struct skcipher_request fallback_req;
 };
 
 /**