[S390] zcrypt: cope with cca restriction of cex3

The cca on the crypto adapter has a restriction in the size of the
exponent if a key with a modulus bigger than 2048 bit is used. Thus
in that case we have to avoid that the crypto device driver thinks
the adapter is defect and sets it offline. Therfore a new member for
the zcrypt_device struct called max_exp_bit_length is introduced. This
will be set the first time the cca returns the error code function
not implemented. If this is done with an adapter twice it will return
-EINVAL.

Signed-off-by: Felix Beck <felix.beck@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/s390/crypto/zcrypt_pcicc.c b/drivers/s390/crypto/zcrypt_pcicc.c
index 9dec5c7..aa4c050 100644
--- a/drivers/s390/crypto/zcrypt_pcicc.c
+++ b/drivers/s390/crypto/zcrypt_pcicc.c
@@ -579,6 +579,7 @@ static int zcrypt_pcicc_probe(struct ap_device *ap_dev)
 	zdev->min_mod_size = PCICC_MIN_MOD_SIZE;
 	zdev->max_mod_size = PCICC_MAX_MOD_SIZE;
 	zdev->speed_rating = PCICC_SPEED_RATING;
+	zdev->max_exp_bit_length = PCICC_MAX_MOD_SIZE;
 	ap_dev->reply = &zdev->reply;
 	ap_dev->private = zdev;
 	rc = zcrypt_device_register(zdev);