[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_pcica.c b/drivers/s390/crypto/zcrypt_pcica.c
index 09e934b295a..1afb69c75fe 100644
--- a/drivers/s390/crypto/zcrypt_pcica.c
+++ b/drivers/s390/crypto/zcrypt_pcica.c
@@ -373,6 +373,7 @@ static int zcrypt_pcica_probe(struct ap_device *ap_dev)
         zdev->min_mod_size = PCICA_MIN_MOD_SIZE;
         zdev->max_mod_size = PCICA_MAX_MOD_SIZE;
         zdev->speed_rating = PCICA_SPEED_RATING;
+        zdev->max_exp_bit_length = PCICA_MAX_MOD_SIZE;
         ap_dev->reply = &zdev->reply;
         ap_dev->private = zdev;
         rc = zcrypt_device_register(zdev);