[PATCH] crypto/qat: fix smaller modulus cases for mod exp

[Arek Kusztal]

This patches fixes not working cases when modulus is
smaller than other arguments.

Fixes: 109755f0a427 ("crypto/qat: refactor asymmetric crypto functions")

Signed-off-by: Arek Kusztal <arkadiuszx.kusztal at intel.com>
---
 drivers/common/qat/qat_adf/qat_pke.h | 24 +++++++++++++++---------
 drivers/crypto/qat/qat_asym.c        | 12 ++++++++++--
 2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/drivers/common/qat/qat_adf/qat_pke.h b/drivers/common/qat/qat_adf/qat_pke.h
index 092fc373de..b5fb2a020c 100644
--- a/drivers/common/qat/qat_adf/qat_pke.h
+++ b/drivers/common/qat/qat_adf/qat_pke.h
@@ -17,32 +17,32 @@ struct qat_asym_function {
 };
 
 static struct qat_asym_function
-get_modexp_function(struct rte_crypto_asym_xform *xform)
+get_modexp_function2(uint32_t bytesize)
 {
 	struct qat_asym_function qat_function = { };
 
-	if (xform->modex.modulus.length <= 64) {
+	if (bytesize <= 64) {
 		qat_function.func_id = MATHS_MODEXP_L512;
 		qat_function.bytesize = 64;
-	} else if (xform->modex.modulus.length <= 128) {
+	} else if (bytesize <= 128) {
 		qat_function.func_id = MATHS_MODEXP_L1024;
 		qat_function.bytesize = 128;
-	} else if (xform->modex.modulus.length <= 192) {
+	} else if (bytesize <= 192) {
 		qat_function.func_id = MATHS_MODEXP_L1536;
 		qat_function.bytesize = 192;
-	} else if (xform->modex.modulus.length <= 256) {
+	} else if (bytesize <= 256) {
 		qat_function.func_id = MATHS_MODEXP_L2048;
 		qat_function.bytesize = 256;
-	} else if (xform->modex.modulus.length <= 320) {
+	} else if (bytesize <= 320) {
 		qat_function.func_id = MATHS_MODEXP_L2560;
 		qat_function.bytesize = 320;
-	} else if (xform->modex.modulus.length <= 384) {
+	} else if (bytesize <= 384) {
 		qat_function.func_id = MATHS_MODEXP_L3072;
 		qat_function.bytesize = 384;
-	} else if (xform->modex.modulus.length <= 448) {
+	} else if (bytesize <= 448) {
 		qat_function.func_id = MATHS_MODEXP_L3584;
 		qat_function.bytesize = 448;
-	} else if (xform->modex.modulus.length <= 512) {
+	} else if (bytesize <= 512) {
 		qat_function.func_id = MATHS_MODEXP_L4096;
 		qat_function.bytesize = 512;
 	}
@@ -50,6 +50,12 @@ get_modexp_function(struct rte_crypto_asym_xform *xform)
 }
 
 static struct qat_asym_function
+get_modexp_function(struct rte_crypto_asym_xform *xform)
+{
+	return get_modexp_function2(xform->modex.modulus.length);
+}
+
+static struct qat_asym_function
 get_modinv_function(struct rte_crypto_asym_xform *xform)
 {
 	struct qat_asym_function qat_function = { };
diff --git a/drivers/crypto/qat/qat_asym.c b/drivers/crypto/qat/qat_asym.c
index badf018f13..25694e52b5 100644
--- a/drivers/crypto/qat/qat_asym.c
+++ b/drivers/crypto/qat/qat_asym.c
@@ -205,7 +205,7 @@ modexp_set_input(struct rte_crypto_asym_op *asym_op,
 		struct rte_crypto_asym_xform *xform)
 {
 	struct qat_asym_function qat_function;
-	uint32_t alg_bytesize, func_id;
+	uint32_t alg_bytesize, func_id, in_bytesize;
 	int status = 0;
 
 	CHECK_IF_NOT_EMPTY(xform->modex.modulus, "mod exp",
@@ -215,7 +215,15 @@ modexp_set_input(struct rte_crypto_asym_op *asym_op,
 	if (status)
 		return status;
 
-	qat_function = get_asym_function(xform);
+	if (asym_op->modex.base.length > xform->modex.exponent.length &&
+		asym_op->modex.base.length > xform->modex.modulus.length) {
+		in_bytesize = asym_op->modex.base.length;
+	} else if (xform->modex.exponent.length > xform->modex.modulus.length)
+		in_bytesize = xform->modex.exponent.length;
+	else
+		in_bytesize = xform->modex.modulus.length;
+
+	qat_function = get_modexp_function2(in_bytesize);
 	func_id = qat_function.func_id;
 	if (qat_function.func_id == 0) {
 		QAT_LOG(ERR, "Cannot obtain functionality id");
-- 
2.13.6