crypto: caam - add support for xcbc(aes)

Add xcbc(aes) offloading support.

Due to xcbc algorithm design and HW implementation in CAAM,
driver must still have some bytes to send to the crypto engine when
ahash_final() is called - such that HW correctly uses either K2 or K3
for the last block.

Signed-off-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

1 files changed, 57 insertions, 1 deletions

diff --git a/drivers/crypto/caam/caamhash_desc.c b/drivers/crypto/caam/caamhash_desc.c
index a12f7959a2c3..053d3a15ef3c 100644
--- a/drivers/crypto/caam/caamhash_desc.c
+++ b/drivers/crypto/caam/caamhash_desc.c
@@ -2,7 +2,7 @@
 /*
  * Shared descriptors for ahash algorithms
  *
- * Copyright 2017 NXP
+ * Copyright 2017-2018 NXP
  */
 
 #include "compat.h"
@@ -75,6 +75,62 @@ void cnstr_shdsc_ahash(u32 * const desc, struct alginfo *adata, u32 state,
 }
 EXPORT_SYMBOL(cnstr_shdsc_ahash);
 
+/**
+ * cnstr_shdsc_axcbc - axcbc shared descriptor
+ * @desc: pointer to buffer used for descriptor construction
+ * @adata: pointer to authentication transform definitions.
+ * @state: algorithm state OP_ALG_AS_{INIT, FINALIZE, INITFINALIZE, UPDATE}
+ * @digestsize: algorithm's digest size
+ * @ctx_len: size of Context Register
+ * @key_dma: I/O Virtual Address of the key
+ */
+void cnstr_shdsc_axcbc(u32 * const desc, struct alginfo *adata, u32 state,
+		       int digestsize, int ctx_len, dma_addr_t key_dma)
+{
+	u32 *skip_key_load;
+
+	init_sh_desc(desc, HDR_SHARE_SERIAL | HDR_SAVECTX);
+
+	/* Skip loading of key, context if already shared */
+	skip_key_load = append_jump(desc, JUMP_TEST_ALL | JUMP_COND_SHRD);
+
+	if (state == OP_ALG_AS_INIT || state == OP_ALG_AS_INITFINAL) {
+		append_key_as_imm(desc, adata->key_virt, adata->keylen,
+				  adata->keylen, CLASS_1 | KEY_DEST_CLASS_REG);
+	} else { /* UPDATE, FINALIZE */
+		/* Load K1 */
+		append_key(desc, adata->key_dma, adata->keylen,
+			   CLASS_1 | KEY_DEST_CLASS_REG | KEY_ENC);
+		/* Restore context */
+		append_seq_load(desc, ctx_len, LDST_CLASS_1_CCB |
+				LDST_SRCDST_BYTE_CONTEXT);
+	}
+
+	set_jump_tgt_here(desc, skip_key_load);
+
+	/* Class 1 operation */
+	append_operation(desc, adata->algtype | state | OP_ALG_ENCRYPT);
+
+	/*
+	 * Load from buf and/or src and write to req->result or state->context
+	 * Calculate remaining bytes to read
+	 */
+	append_math_add(desc, VARSEQINLEN, SEQINLEN, REG0, CAAM_CMD_SZ);
+
+	/* Read remaining bytes */
+	append_seq_fifo_load(desc, 0, FIFOLD_CLASS_CLASS1 | FIFOLD_TYPE_LAST1 |
+			     FIFOLD_TYPE_MSG | FIFOLDST_VLF);
+
+	/* Save context (partial hash, K2, K3) */
+	append_seq_store(desc, digestsize, LDST_CLASS_1_CCB |
+			 LDST_SRCDST_BYTE_CONTEXT);
+	if (state == OP_ALG_AS_INIT)
+		/* Save K1 */
+		append_fifo_store(desc, key_dma, adata->keylen,
+				  LDST_CLASS_1_CCB | FIFOST_TYPE_KEY_KEK);
+}
+EXPORT_SYMBOL(cnstr_shdsc_axcbc);
+
 MODULE_LICENSE("Dual BSD/GPL");
 MODULE_DESCRIPTION("FSL CAAM ahash descriptors support");
 MODULE_AUTHOR("NXP Semiconductors");