[PATCH 4.6 14/31] crypto: vmx - Increase priority of aes-cbc cipher

[Greg Kroah-Hartman]

4.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Anton Blanchard <anton@xxxxxxxxx>

commit 12d3f49e1ffbbf8cbbb60acae5a21103c5c841ac upstream.

All of the VMX AES ciphers (AES, AES-CBC and AES-CTR) are set at
priority 1000. Unfortunately this means we never use AES-CBC and
AES-CTR, because the base AES-CBC cipher that is implemented on
top of AES inherits its priority.

To fix this, AES-CBC and AES-CTR have to be a higher priority. Set
them to 2000.

Testing on a POWER8 with:

cryptsetup benchmark --cipher aes --key-size 256

Shows decryption speed increase from 402.4 MB/s to 3069.2 MB/s,
over 7x faster. Thanks to Mike Strosaker for helping me debug
this issue.

Fixes: 8c755ace357c ("crypto: vmx - Adding CBC routines for VMX module")
Signed-off-by: Anton Blanchard <anton@xxxxxxxxx>
Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/crypto/vmx/aes_cbc.c |    2 +-
 drivers/crypto/vmx/aes_ctr.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/crypto/vmx/aes_cbc.c
+++ b/drivers/crypto/vmx/aes_cbc.c
@@ -182,7 +182,7 @@ struct crypto_alg p8_aes_cbc_alg = {
 	.cra_name = "cbc(aes)",
 	.cra_driver_name = "p8_aes_cbc",
 	.cra_module = THIS_MODULE,
-	.cra_priority = 1000,
+	.cra_priority = 2000,
 	.cra_type = &crypto_blkcipher_type,
 	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK,
 	.cra_alignmask = 0,
--- a/drivers/crypto/vmx/aes_ctr.c
+++ b/drivers/crypto/vmx/aes_ctr.c
@@ -166,7 +166,7 @@ struct crypto_alg p8_aes_ctr_alg = {
 	.cra_name = "ctr(aes)",
 	.cra_driver_name = "p8_aes_ctr",
 	.cra_module = THIS_MODULE,
-	.cra_priority = 1000,
+	.cra_priority = 2000,
 	.cra_type = &crypto_blkcipher_type,
 	.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER | CRYPTO_ALG_NEED_FALLBACK,
 	.cra_alignmask = 0,