crypto: caam - update rfc4106 sh desc to support zero length input

Update share descriptor for rfc4106 to skip instructions in case
cryptlen is zero. If no instructions are jumped the DECO hangs and a
timeout error is thrown.

Signed-off-by: Iuliana Prodan <[e-mail]>
Reviewed-by: Horia Geanta <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

drivers/crypto/caam/caamalg_desc.c

···
  * @ivsize: initialization vector size
  * @icvsize: integrity check value (ICV) size (truncated or full)
  * @is_qi: true when called from caam/qi
+ *
+ * Input sequence: AAD | PTXT
+ * Output sequence: AAD | CTXT | ICV
+ * AAD length (assoclen), which includes the IV length, is available in Math3.
  */
 void cnstr_shdsc_rfc4106_encap(u32 * const desc, struct alginfo *cdata,
 			       unsigned int ivsize, unsigned int icvsize,
 			       const bool is_qi)
 {
-	u32 *key_jump_cmd;
-
+	u32 *key_jump_cmd, *zero_cryptlen_jump_cmd, *skip_instructions;
 	init_sh_desc(desc, HDR_SHARE_SERIAL);
 
 	/* Skip key loading if it is loaded due to sharing */
···
 	append_math_sub_imm_u32(desc, VARSEQINLEN, REG3, IMM, ivsize);
 	append_math_add(desc, VARSEQOUTLEN, ZERO, REG3, CAAM_CMD_SZ);
 
-	/* Read assoc data */
+	/* Skip AAD */
+	append_seq_fifo_store(desc, 0, FIFOST_TYPE_SKIP | FIFOLDST_VLF);
+
+	/* Read cryptlen and set this value into VARSEQOUTLEN */
+	append_math_sub(desc, VARSEQOUTLEN, SEQINLEN, REG3, CAAM_CMD_SZ);
+
+	/* If cryptlen is ZERO jump to AAD command */
+	zero_cryptlen_jump_cmd = append_jump(desc, JUMP_TEST_ALL |
+					    JUMP_COND_MATH_Z);
+
+	/* Read AAD data */
 	append_seq_fifo_load(desc, 0, FIFOLD_CLASS_CLASS1 | FIFOLDST_VLF |
 			     FIFOLD_TYPE_AAD | FIFOLD_TYPE_FLUSH1);
 
+	/* Workaround for erratum A-005473 (simultaneous SEQ FIFO skips) */
+	append_seq_fifo_store(desc, 0, FIFOST_TYPE_MESSAGE_DATA);
+
 	/* Skip IV */
 	append_seq_fifo_load(desc, ivsize, FIFOLD_CLASS_SKIP);
-
-	/* Will read cryptlen bytes */
-	append_math_sub(desc, VARSEQINLEN, SEQINLEN, REG0, CAAM_CMD_SZ);
-
-	/* Workaround for erratum A-005473 (simultaneous SEQ FIFO skips) */
-	append_seq_fifo_load(desc, 0, FIFOLD_CLASS_CLASS1 | FIFOLD_TYPE_MSG);
-
-	/* Skip assoc data */
-	append_seq_fifo_store(desc, 0, FIFOST_TYPE_SKIP | FIFOLDST_VLF);
-
-	/* cryptlen = seqoutlen - assoclen */
-	append_math_sub(desc, VARSEQOUTLEN, VARSEQINLEN, REG0, CAAM_CMD_SZ);
+	append_math_add(desc, VARSEQINLEN, VARSEQOUTLEN, REG0, CAAM_CMD_SZ);
 
 	/* Write encrypted data */
 	append_seq_fifo_store(desc, 0, FIFOST_TYPE_MESSAGE_DATA | FIFOLDST_VLF);
···
 	/* Read payload data */
 	append_seq_fifo_load(desc, 0, FIFOLD_CLASS_CLASS1 | FIFOLDST_VLF |
 			     FIFOLD_TYPE_MSG | FIFOLD_TYPE_LAST1);
+
+	/* Jump instructions to avoid double reading of AAD */
+	skip_instructions = append_jump(desc, JUMP_TEST_ALL);
+
+	/* There is no input data, cryptlen = 0 */
+	set_jump_tgt_here(desc, zero_cryptlen_jump_cmd);
+
+	/* Read AAD */
+	append_seq_fifo_load(desc, 0, FIFOLD_CLASS_CLASS1 | FIFOLDST_VLF |
+			     FIFOLD_TYPE_AAD | FIFOLD_TYPE_LAST1);
+
+	set_jump_tgt_here(desc, skip_instructions);
 
 	/* Write ICV */
 	append_seq_store(desc, icvsize, LDST_CLASS_1_CCB |

drivers/crypto/caam/caamalg_desc.h

···
 #define DESC_QI_GCM_DEC_LEN		(DESC_GCM_DEC_LEN + 3 * CAAM_CMD_SZ)
 
 #define DESC_RFC4106_BASE		(3 * CAAM_CMD_SZ)
-#define DESC_RFC4106_ENC_LEN		(DESC_RFC4106_BASE + 13 * CAAM_CMD_SZ)
+#define DESC_RFC4106_ENC_LEN		(DESC_RFC4106_BASE + 16 * CAAM_CMD_SZ)
 #define DESC_RFC4106_DEC_LEN		(DESC_RFC4106_BASE + 13 * CAAM_CMD_SZ)
 #define DESC_QI_RFC4106_ENC_LEN		(DESC_RFC4106_ENC_LEN + 5 * CAAM_CMD_SZ)
 #define DESC_QI_RFC4106_DEC_LEN		(DESC_RFC4106_DEC_LEN + 5 * CAAM_CMD_SZ)