From: Sebastian Siewior <[EMAIL PROTECTED]>

The Geode AES crypto engine supports only 128 bit long key. This
patch adds fallback for other key sizes which are required by the
AES standard.

Signed-off-by: Sebastian Siewior <[EMAIL PROTECTED]>
---
 drivers/crypto/geode-aes.c |  188 +++++++++++++++++++++++++++++++++++++++-----
 drivers/crypto/geode-aes.h |    6 ++
 2 files changed, 173 insertions(+), 21 deletions(-)

diff --git a/drivers/crypto/geode-aes.c b/drivers/crypto/geode-aes.c
index da6164a..761d600 100644
--- a/drivers/crypto/geode-aes.c
+++ b/drivers/crypto/geode-aes.c
@@ -118,14 +118,82 @@ static int
 geode_setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int len)
 {
        struct geode_aes_op *op = crypto_tfm_ctx(tfm);
+       unsigned int type;
+       unsigned int ret;
 
-       if (len != AES_KEY_LENGTH) {
+       op->keylen = len;
+
+       if (len == AES_KEY_LENGTH) {
+               memcpy(op->key, key, len);
+               return 0;
+       }
+
+       if (len != 24 && len != 32) {
+               /* not supported at all */
                tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
                return -EINVAL;
        }
 
-       memcpy(op->key, key, len);
-       return 0;
+       /*
+        * The requested key size is not supported by HW, do a fallback
+        */
+
+       type = tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
+
+       /* propagate requested flags to the fallback driver */
+       op->fallback.blk->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
+       op->fallback.blk->base.crt_flags |= (tfm->crt_flags & 
CRYPTO_TFM_REQ_MASK);
+
+       if (type == CRYPTO_ALG_TYPE_BLKCIPHER) {
+               ret = crypto_blkcipher_setkey(op->fallback.blk, key, len);
+
+       } else if (type == CRYPTO_ALG_TYPE_CIPHER) {
+               ret = crypto_cipher_setkey(op->fallback.cip, key, len);
+
+       } else {
+               printk(KERN_ERR "Neither a cipher nor a block cipher. %x / 
%x\n",
+                               type, tfm->crt_flags);
+               return -EINVAL;
+       }
+
+       if (ret) {
+               tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;
+               tfm->crt_flags |= (op->fallback.blk->base.crt_flags & 
CRYPTO_TFM_RES_MASK);
+       }
+       return ret;
+}
+
+static int fallback_blk_dec(struct blkcipher_desc *desc,
+               struct scatterlist *dst, struct scatterlist *src,
+               unsigned int nbytes)
+{
+       unsigned int ret;
+       struct crypto_blkcipher *tfm;
+       struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
+
+       tfm = desc->tfm;
+       desc->tfm = op->fallback.blk;
+
+       ret = crypto_blkcipher_decrypt(desc, dst, src, nbytes);
+
+       desc->tfm = tfm;
+       return ret;
+}
+static int fallback_blk_enc(struct blkcipher_desc *desc,
+               struct scatterlist *dst, struct scatterlist *src,
+               unsigned int nbytes)
+{
+       unsigned int ret;
+       struct crypto_blkcipher *tfm;
+       struct geode_aes_op *op = crypto_blkcipher_ctx(desc->tfm);
+
+       tfm = desc->tfm;
+       desc->tfm = op->fallback.blk;
+
+       ret = crypto_blkcipher_encrypt(desc, dst, src, nbytes);
+
+       desc->tfm = tfm;
+       return ret;
 }
 
 static void
@@ -133,8 +201,10 @@ geode_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 
*in)
 {
        struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 
-       if ((out == NULL) || (in == NULL))
+       if (unlikely(op->keylen != 16)) {
+               crypto_cipher_encrypt_one(op->fallback.cip, out, in);
                return;
+       }
 
        op->src = (void *) in;
        op->dst = (void *) out;
@@ -152,8 +222,10 @@ geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 
*in)
 {
        struct geode_aes_op *op = crypto_tfm_ctx(tfm);
 
-       if ((out == NULL) || (in == NULL))
+       if (unlikely(op->keylen != 16)) {
+               crypto_cipher_decrypt_one(op->fallback.cip, out, in);
                return;
+       }
 
        op->src = (void *) in;
        op->dst = (void *) out;
@@ -165,21 +237,76 @@ geode_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 
*in)
        geode_aes_crypt(op);
 }
 
+static int fallback_init(struct crypto_tfm *tfm)
+{
+       const char *name = tfm->__crt_alg->cra_name;
+       unsigned int type;
+       struct geode_aes_op *op = crypto_tfm_ctx(tfm);
+
+       type = tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
+
+       if (type == CRYPTO_ALG_TYPE_BLKCIPHER) {
+               op->fallback.blk = crypto_alloc_blkcipher(name, 0,
+                               CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);
+
+       } else if (type == CRYPTO_ALG_TYPE_CIPHER) {
+               op->fallback.cip = crypto_alloc_cipher(name, 0,
+                               CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK);
+       } else {
+               printk(KERN_ERR "%s is neither a cipher nor a block cipher: 
%x\n",
+                               name, type);
+               return -EINVAL;
+       }
+
+       /*
+        * cipher / blkcipher, this is the same pointer for both. One check is
+        * enough
+        */
+       if (IS_ERR(op->fallback.blk)) {
+               printk(KERN_ERR "Error allocating fallback algo %s\n", name);
+               return PTR_ERR(op->fallback.blk);
+       }
+
+       return 0;
+}
+
+static void fallback_exit(struct crypto_tfm *tfm)
+{
+       unsigned int type;
+       struct geode_aes_op *op = crypto_tfm_ctx(tfm);
+
+       type = tfm->__crt_alg->cra_flags & CRYPTO_ALG_TYPE_MASK;
+       if (type == CRYPTO_ALG_TYPE_BLKCIPHER) {
+               crypto_free_blkcipher(op->fallback.blk);
+               op->fallback.blk = NULL;
+               return;
+
+       } else if (type == CRYPTO_ALG_TYPE_CIPHER) {
+               crypto_free_cipher(op->fallback.cip);
+               op->fallback.cip = NULL;
+               return;
+       }
+
+       WARN_ON(1);
+}
 
 static struct crypto_alg geode_alg = {
        .cra_name               =       "aes",
-       .cra_driver_name        =       "geode-aes-128",
+       .cra_driver_name        =       "geode-aes",
        .cra_priority           =       300,
        .cra_alignmask          =       15,
-       .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER,
+       .cra_flags              =       CRYPTO_ALG_TYPE_CIPHER |
+                                       CRYPTO_ALG_NEED_FALLBACK,
+       .cra_init               =       fallback_init,
+       .cra_exit               =       fallback_exit,
        .cra_blocksize          =       AES_MIN_BLOCK_SIZE,
        .cra_ctxsize            =       sizeof(struct geode_aes_op),
        .cra_module             =       THIS_MODULE,
        .cra_list               =       LIST_HEAD_INIT(geode_alg.cra_list),
        .cra_u                  =       {
                .cipher = {
-                       .cia_min_keysize        =  AES_KEY_LENGTH,
-                       .cia_max_keysize        =  AES_KEY_LENGTH,
+                       .cia_min_keysize        =  AES_MIN_KEY_SIZE,
+                       .cia_max_keysize        =  AES_MAX_KEY_SIZE,
                        .cia_setkey             =  geode_setkey,
                        .cia_encrypt            =  geode_encrypt,
                        .cia_decrypt            =  geode_decrypt
@@ -196,6 +323,9 @@ geode_cbc_decrypt(struct blkcipher_desc *desc,
        struct blkcipher_walk walk;
        int err, ret;
 
+       if (unlikely(op->keylen != 16))
+               return fallback_blk_dec(desc, dst, src, nbytes);
+
        blkcipher_walk_init(&walk, dst, src, nbytes);
        err = blkcipher_walk_virt(desc, &walk);
        memcpy(op->iv, walk.iv, AES_IV_LENGTH);
@@ -226,6 +356,9 @@ geode_cbc_encrypt(struct blkcipher_desc *desc,
        struct blkcipher_walk walk;
        int err, ret;
 
+       if (unlikely(op->keylen != 16))
+               return fallback_blk_enc(desc, dst, src, nbytes);
+
        blkcipher_walk_init(&walk, dst, src, nbytes);
        err = blkcipher_walk_virt(desc, &walk);
        memcpy(op->iv, walk.iv, AES_IV_LENGTH);
@@ -248,9 +381,12 @@ geode_cbc_encrypt(struct blkcipher_desc *desc,
 
 static struct crypto_alg geode_cbc_alg = {
        .cra_name               =       "cbc(aes)",
-       .cra_driver_name        =       "cbc-aes-geode-128",
-       .cra_priority           =       400,
-       .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER,
+       .cra_driver_name        =       "cbc-aes-geode",
+       .cra_priority           =       300,
+       .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER |
+                                       CRYPTO_ALG_NEED_FALLBACK,
+       .cra_init               =       fallback_init,
+       .cra_exit               =       fallback_exit,
        .cra_blocksize          =       AES_MIN_BLOCK_SIZE,
        .cra_ctxsize            =       sizeof(struct geode_aes_op),
        .cra_alignmask          =       15,
@@ -259,8 +395,8 @@ static struct crypto_alg geode_cbc_alg = {
        .cra_list               =       LIST_HEAD_INIT(geode_cbc_alg.cra_list),
        .cra_u                  =       {
                .blkcipher = {
-                       .min_keysize            =       AES_KEY_LENGTH,
-                       .max_keysize            =       AES_KEY_LENGTH,
+                       .min_keysize            =       AES_MIN_KEY_SIZE,
+                       .max_keysize            =       AES_MAX_KEY_SIZE,
                        .setkey                 =       geode_setkey,
                        .encrypt                =       geode_cbc_encrypt,
                        .decrypt                =       geode_cbc_decrypt,
@@ -278,6 +414,9 @@ geode_ecb_decrypt(struct blkcipher_desc *desc,
        struct blkcipher_walk walk;
        int err, ret;
 
+       if (unlikely(op->keylen != 16))
+               return fallback_blk_dec(desc, dst, src, nbytes);
+
        blkcipher_walk_init(&walk, dst, src, nbytes);
        err = blkcipher_walk_virt(desc, &walk);
 
@@ -305,6 +444,9 @@ geode_ecb_encrypt(struct blkcipher_desc *desc,
        struct blkcipher_walk walk;
        int err, ret;
 
+       if (unlikely(op->keylen != 16))
+               return fallback_blk_enc(desc, dst, src, nbytes);
+
        blkcipher_walk_init(&walk, dst, src, nbytes);
        err = blkcipher_walk_virt(desc, &walk);
 
@@ -325,9 +467,12 @@ geode_ecb_encrypt(struct blkcipher_desc *desc,
 
 static struct crypto_alg geode_ecb_alg = {
        .cra_name               =       "ecb(aes)",
-       .cra_driver_name        =       "ecb-aes-geode-128",
-       .cra_priority           =       400,
-       .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER,
+       .cra_driver_name        =       "ecb-aes-geode",
+       .cra_priority           =       300,
+       .cra_flags              =       CRYPTO_ALG_TYPE_BLKCIPHER |
+                                       CRYPTO_ALG_NEED_FALLBACK,
+       .cra_init               =       fallback_init,
+       .cra_exit               =       fallback_exit,
        .cra_blocksize          =       AES_MIN_BLOCK_SIZE,
        .cra_ctxsize            =       sizeof(struct geode_aes_op),
        .cra_alignmask          =       15,
@@ -336,8 +481,8 @@ static struct crypto_alg geode_ecb_alg = {
        .cra_list               =       LIST_HEAD_INIT(geode_ecb_alg.cra_list),
        .cra_u                  =       {
                .blkcipher = {
-                       .min_keysize            =       AES_KEY_LENGTH,
-                       .max_keysize            =       AES_KEY_LENGTH,
+                       .min_keysize            =       AES_MIN_KEY_SIZE,
+                       .max_keysize            =       AES_MAX_KEY_SIZE,
                        .setkey                 =       geode_setkey,
                        .encrypt                =       geode_ecb_encrypt,
                        .decrypt                =       geode_ecb_decrypt,
@@ -368,7 +513,7 @@ geode_aes_probe(struct pci_dev *dev, const struct 
pci_device_id *id)
        if ((ret = pci_enable_device(dev)))
                return ret;
 
-       if ((ret = pci_request_regions(dev, "geode-aes-128")))
+       if ((ret = pci_request_regions(dev, "geode-aes")))
                goto eenable;
 
        _iobase = pci_iomap(dev, 0, 0);
@@ -392,7 +537,8 @@ geode_aes_probe(struct pci_dev *dev, const struct 
pci_device_id *id)
        if ((ret = crypto_register_alg(&geode_cbc_alg)))
                goto eecb;
 
-       printk(KERN_NOTICE "geode-aes: GEODE AES engine enabled.\n");
+       printk(KERN_NOTICE "geode-aes: GEODE AES engine enabled. "
+                       "Only 128-bit keys are supported by the Hardware.\n");
        return 0;
 
  eecb:
diff --git a/drivers/crypto/geode-aes.h b/drivers/crypto/geode-aes.h
index 2f1d559..14cc763 100644
--- a/drivers/crypto/geode-aes.h
+++ b/drivers/crypto/geode-aes.h
@@ -66,6 +66,12 @@ struct geode_aes_op {
 
        u8 key[AES_KEY_LENGTH];
        u8 iv[AES_IV_LENGTH];
+
+       union {
+               struct crypto_blkcipher *blk;
+               struct crypto_cipher *cip;
+       } fallback;
+       u32 keylen;
 };
 
 #endif
-- 
1.5.3.4

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