crypto: caam - add support for acipher xts(aes)

Add support for AES working in XEX-based Tweaked-codebook mode with
ciphertext Stealing (XTS)

sector index - HW limitation: CAAM device supports sector index of only
8 bytes to be used for sector index inside IV, instead of whole 16 bytes
received on request. This represents 2 ^ 64 = 16,777,216 Tera of possible
values for sector index.

Signed-off-by: Cristian Hristea <cristi.hristea@gmail.com>
Signed-off-by: Horia Geanta <horia.geanta@freescale.com>
Signed-off-by: Alex Porosanu <alexandru.porosanu@freescale.com>
Signed-off-by: Catalin Vasile <catalin.vasile@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c
index ad0d1ec51dd5d7438022768a5e4f545b95a8b97a..ea8189f4b0212cc038f5f4363cf10f5e8a54099a 100644 (file)
--- a/drivers/crypto/caam/caamalg.c
+++ b/drivers/crypto/caam/caamalg.c
@@ -1705,6 +1705,126 @@ static int ablkcipher_setkey(struct crypto_ablkcipher *ablkcipher,
        return ret;
 }
 
+static int xts_ablkcipher_setkey(struct crypto_ablkcipher *ablkcipher,
+                                const u8 *key, unsigned int keylen)
+{
+       struct caam_ctx *ctx = crypto_ablkcipher_ctx(ablkcipher);
+       struct device *jrdev = ctx->jrdev;
+       u32 *key_jump_cmd, *desc;
+       __be64 sector_size = cpu_to_be64(512);
+
+       if (keylen != 2 * AES_MIN_KEY_SIZE  && keylen != 2 * AES_MAX_KEY_SIZE) {
+               crypto_ablkcipher_set_flags(ablkcipher,
+                                           CRYPTO_TFM_RES_BAD_KEY_LEN);
+               dev_err(jrdev, "key size mismatch\n");
+               return -EINVAL;
+       }
+
+       memcpy(ctx->key, key, keylen);
+       ctx->key_dma = dma_map_single(jrdev, ctx->key, keylen, DMA_TO_DEVICE);
+       if (dma_mapping_error(jrdev, ctx->key_dma)) {
+               dev_err(jrdev, "unable to map key i/o memory\n");
+               return -ENOMEM;
+       }
+       ctx->enckeylen = keylen;
+
+       /* xts_ablkcipher_encrypt shared descriptor */
+       desc = ctx->sh_desc_enc;
+       init_sh_desc(desc, HDR_SHARE_SERIAL | HDR_SAVECTX);
+       /* Skip if already shared */
+       key_jump_cmd = append_jump(desc, JUMP_JSL | JUMP_TEST_ALL |
+                                  JUMP_COND_SHRD);
+
+       /* Load class1 keys only */
+       append_key_as_imm(desc, (void *)ctx->key, ctx->enckeylen,
+                         ctx->enckeylen, CLASS_1 | KEY_DEST_CLASS_REG);
+
+       /* Load sector size with index 40 bytes (0x28) */
+       append_cmd(desc, CMD_LOAD | IMMEDIATE | LDST_SRCDST_BYTE_CONTEXT |
+                  LDST_CLASS_1_CCB | (0x28 << LDST_OFFSET_SHIFT) | 8);
+       append_data(desc, (void *)&sector_size, 8);
+
+       set_jump_tgt_here(desc, key_jump_cmd);
+
+       /*
+        * create sequence for loading the sector index
+        * Upper 8B of IV - will be used as sector index
+        * Lower 8B of IV - will be discarded
+        */
+       append_cmd(desc, CMD_SEQ_LOAD | LDST_SRCDST_BYTE_CONTEXT |
+                  LDST_CLASS_1_CCB | (0x20 << LDST_OFFSET_SHIFT) | 8);
+       append_seq_fifo_load(desc, 8, FIFOLD_CLASS_SKIP);
+
+       /* Load operation */
+       append_operation(desc, ctx->class1_alg_type | OP_ALG_AS_INITFINAL |
+                        OP_ALG_ENCRYPT);
+
+       /* Perform operation */
+       ablkcipher_append_src_dst(desc);
+
+       ctx->sh_desc_enc_dma = dma_map_single(jrdev, desc, desc_bytes(desc),
+                                             DMA_TO_DEVICE);
+       if (dma_mapping_error(jrdev, ctx->sh_desc_enc_dma)) {
+               dev_err(jrdev, "unable to map shared descriptor\n");
+               return -ENOMEM;
+       }
+#ifdef DEBUG
+       print_hex_dump(KERN_ERR,
+                      "xts ablkcipher enc shdesc@" __stringify(__LINE__) ": ",
+                      DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), 1);
+#endif
+
+       /* xts_ablkcipher_decrypt shared descriptor */
+       desc = ctx->sh_desc_dec;
+
+       init_sh_desc(desc, HDR_SHARE_SERIAL | HDR_SAVECTX);
+       /* Skip if already shared */
+       key_jump_cmd = append_jump(desc, JUMP_JSL | JUMP_TEST_ALL |
+                                  JUMP_COND_SHRD);
+
+       /* Load class1 key only */
+       append_key_as_imm(desc, (void *)ctx->key, ctx->enckeylen,
+                         ctx->enckeylen, CLASS_1 | KEY_DEST_CLASS_REG);
+
+       /* Load sector size with index 40 bytes (0x28) */
+       append_cmd(desc, CMD_LOAD | IMMEDIATE | LDST_SRCDST_BYTE_CONTEXT |
+                  LDST_CLASS_1_CCB | (0x28 << LDST_OFFSET_SHIFT) | 8);
+       append_data(desc, (void *)&sector_size, 8);
+
+       set_jump_tgt_here(desc, key_jump_cmd);
+
+       /*
+        * create sequence for loading the sector index
+        * Upper 8B of IV - will be used as sector index
+        * Lower 8B of IV - will be discarded
+        */
+       append_cmd(desc, CMD_SEQ_LOAD | LDST_SRCDST_BYTE_CONTEXT |
+                  LDST_CLASS_1_CCB | (0x20 << LDST_OFFSET_SHIFT) | 8);
+       append_seq_fifo_load(desc, 8, FIFOLD_CLASS_SKIP);
+
+       /* Load operation */
+       append_dec_op1(desc, ctx->class1_alg_type);
+
+       /* Perform operation */
+       ablkcipher_append_src_dst(desc);
+
+       ctx->sh_desc_dec_dma = dma_map_single(jrdev, desc, desc_bytes(desc),
+                                             DMA_TO_DEVICE);
+       if (dma_mapping_error(jrdev, ctx->sh_desc_dec_dma)) {
+               dma_unmap_single(jrdev, ctx->sh_desc_enc_dma,
+                                desc_bytes(ctx->sh_desc_enc), DMA_TO_DEVICE);
+               dev_err(jrdev, "unable to map shared descriptor\n");
+               return -ENOMEM;
+       }
+#ifdef DEBUG
+       print_hex_dump(KERN_ERR,
+                      "xts ablkcipher dec shdesc@" __stringify(__LINE__) ": ",
+                      DUMP_PREFIX_ADDRESS, 16, 4, desc, desc_bytes(desc), 1);
+#endif
+
+       return 0;
+}
+
 /*
  * aead_edesc - s/w-extended aead descriptor
  * @assoc_nents: number of segments in associated data (SPI+Seq) scatterlist
@@ -2845,7 +2965,23 @@ static struct caam_alg_template driver_algs[] = {
                        .ivsize = CTR_RFC3686_IV_SIZE,
                        },
                .class1_alg_type = OP_ALG_ALGSEL_AES | OP_ALG_AAI_CTR_MOD128,
-       }
+       },
+       {
+               .name = "xts(aes)",
+               .driver_name = "xts-aes-caam",
+               .blocksize = AES_BLOCK_SIZE,
+               .type = CRYPTO_ALG_TYPE_ABLKCIPHER,
+               .template_ablkcipher = {
+                       .setkey = xts_ablkcipher_setkey,
+                       .encrypt = ablkcipher_encrypt,
+                       .decrypt = ablkcipher_decrypt,
+                       .geniv = "eseqiv",
+                       .min_keysize = 2 * AES_MIN_KEY_SIZE,
+                       .max_keysize = 2 * AES_MAX_KEY_SIZE,
+                       .ivsize = AES_BLOCK_SIZE,
+                       },
+               .class1_alg_type = OP_ALG_ALGSEL_AES | OP_ALG_AAI_XTS,
+       },
 };
 
 static struct caam_aead_alg driver_aeads[] = {