crypto: omap-aes - Add fallback support

As setting up the DMA operations is quite costly, add software fallback
support for requests smaller than 200 bytes. This change gives some 10%
extra performance in ipsec use case.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
[t-kristo@ti.com: udpated against latest upstream, to use skcipher mainly]
Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
index 1af94e2d1a2596daa7f57f73b37a083ccd3c285d..19ee6ee60f39c2762519fc6174cdaa3b0efb5aca 100644 (file)
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -318,6 +318,9 @@ config CRYPTO_DEV_OMAP_AES
        select CRYPTO_AES
        select CRYPTO_BLKCIPHER
        select CRYPTO_ENGINE
+       select CRYPTO_CBC
+       select CRYPTO_ECB
+       select CRYPTO_CTR
        help
          OMAP processors have AES module accelerator. Select this if you
          want to use the OMAP module for AES algorithms.

diff --git a/drivers/crypto/omap-aes.c b/drivers/crypto/omap-aes.c
index 7615026709fec8b957957185ec4d84d705e04ff3..975288dc5139ed178f2c0610f541008a3202d618 100644 (file)
--- a/drivers/crypto/omap-aes.c
+++ b/drivers/crypto/omap-aes.c
@@ -35,8 +35,8 @@
 #include <linux/interrupt.h>
 #include <crypto/scatterwalk.h>
 #include <crypto/aes.h>
-#include <crypto/algapi.h>
 #include <crypto/engine.h>
+#include <crypto/internal/skcipher.h>
 
 #define DST_MAXBURST                   4
 #define DMA_MIN                                (DST_MAXBURST * sizeof(u32))
@@ -106,6 +106,7 @@ struct omap_aes_ctx {
        int             keylen;
        u32             key[AES_KEYSIZE_256 / sizeof(u32)];
        unsigned long   flags;
+       struct crypto_skcipher  *fallback;
 };
 
 struct omap_aes_reqctx {
@@ -702,11 +703,29 @@ static int omap_aes_crypt(struct ablkcipher_request *req, unsigned long mode)
                        crypto_ablkcipher_reqtfm(req));
        struct omap_aes_reqctx *rctx = ablkcipher_request_ctx(req);
        struct omap_aes_dev *dd;
+       int ret;
 
        pr_debug("nbytes: %d, enc: %d, cbc: %d\n", req->nbytes,
                  !!(mode & FLAGS_ENCRYPT),
                  !!(mode & FLAGS_CBC));
 
+       if (req->nbytes < 200) {
+               SKCIPHER_REQUEST_ON_STACK(subreq, ctx->fallback);
+
+               skcipher_request_set_tfm(subreq, ctx->fallback);
+               skcipher_request_set_callback(subreq, req->base.flags, NULL,
+                                             NULL);
+               skcipher_request_set_crypt(subreq, req->src, req->dst,
+                                          req->nbytes, req->info);
+
+               if (mode & FLAGS_ENCRYPT)
+                       ret = crypto_skcipher_encrypt(subreq);
+               else
+                       ret = crypto_skcipher_decrypt(subreq);
+
+               skcipher_request_zero(subreq);
+               return ret;
+       }
        dd = omap_aes_find_dev(ctx);
        if (!dd)
                return -ENODEV;
@@ -722,6 +741,7 @@ static int omap_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
                           unsigned int keylen)
 {
        struct omap_aes_ctx *ctx = crypto_ablkcipher_ctx(tfm);
+       int ret;
 
        if (keylen != AES_KEYSIZE_128 && keylen != AES_KEYSIZE_192 &&
                   keylen != AES_KEYSIZE_256)
@@ -732,6 +752,14 @@ static int omap_aes_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
        memcpy(ctx->key, key, keylen);
        ctx->keylen = keylen;
 
+       crypto_skcipher_clear_flags(ctx->fallback, CRYPTO_TFM_REQ_MASK);
+       crypto_skcipher_set_flags(ctx->fallback, tfm->base.crt_flags &
+                                                CRYPTO_TFM_REQ_MASK);
+
+       ret = crypto_skcipher_setkey(ctx->fallback, key, keylen);
+       if (!ret)
+               return 0;
+
        return 0;
 }
 
@@ -767,6 +795,17 @@ static int omap_aes_ctr_decrypt(struct ablkcipher_request *req)
 
 static int omap_aes_cra_init(struct crypto_tfm *tfm)
 {
+       const char *name = crypto_tfm_alg_name(tfm);
+       const u32 flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK;
+       struct omap_aes_ctx *ctx = crypto_tfm_ctx(tfm);
+       struct crypto_skcipher *blk;
+
+       blk = crypto_alloc_skcipher(name, 0, flags);
+       if (IS_ERR(blk))
+               return PTR_ERR(blk);
+
+       ctx->fallback = blk;
+
        tfm->crt_ablkcipher.reqsize = sizeof(struct omap_aes_reqctx);
 
        return 0;
@@ -774,6 +813,12 @@ static int omap_aes_cra_init(struct crypto_tfm *tfm)
 
 static void omap_aes_cra_exit(struct crypto_tfm *tfm)
 {
+       struct omap_aes_ctx *ctx = crypto_tfm_ctx(tfm);
+
+       if (ctx->fallback)
+               crypto_free_skcipher(ctx->fallback);
+
+       ctx->fallback = NULL;
 }
 
 /* ********************** ALGS ************************************ */
@@ -785,7 +830,7 @@ static struct crypto_alg algs_ecb_cbc[] = {
        .cra_priority           = 300,
        .cra_flags              = CRYPTO_ALG_TYPE_ABLKCIPHER |
                                  CRYPTO_ALG_KERN_DRIVER_ONLY |
-                                 CRYPTO_ALG_ASYNC,
+                                 CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
        .cra_blocksize          = AES_BLOCK_SIZE,
        .cra_ctxsize            = sizeof(struct omap_aes_ctx),
        .cra_alignmask          = 0,
@@ -807,7 +852,7 @@ static struct crypto_alg algs_ecb_cbc[] = {
        .cra_priority           = 300,
        .cra_flags              = CRYPTO_ALG_TYPE_ABLKCIPHER |
                                  CRYPTO_ALG_KERN_DRIVER_ONLY |
-                                 CRYPTO_ALG_ASYNC,
+                                 CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
        .cra_blocksize          = AES_BLOCK_SIZE,
        .cra_ctxsize            = sizeof(struct omap_aes_ctx),
        .cra_alignmask          = 0,
@@ -833,7 +878,7 @@ static struct crypto_alg algs_ctr[] = {
        .cra_priority           = 300,
        .cra_flags              = CRYPTO_ALG_TYPE_ABLKCIPHER |
                                  CRYPTO_ALG_KERN_DRIVER_ONLY |
-                                 CRYPTO_ALG_ASYNC,
+                                 CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK,
        .cra_blocksize          = AES_BLOCK_SIZE,
        .cra_ctxsize            = sizeof(struct omap_aes_ctx),
        .cra_alignmask          = 0,