[S390] zcrypt: add support for large random numbers

This patch allows user space applications to access large amounts of
truly random data. The random data source is the build-in hardware
random number generator on the CEX2C cards.

Signed-off-by: Ralph Wuerthner <rwuerthn@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>

1 files changed, 8 insertions, 0 deletions

diff --git a/drivers/s390/crypto/zcrypt_api.h b/drivers/s390/crypto/zcrypt_api.h
index de4877ee618f..0e948528a73a 100644
--- a/drivers/s390/crypto/zcrypt_api.h
+++ b/drivers/s390/crypto/zcrypt_api.h
@@ -100,6 +100,13 @@ struct ica_z90_status {
 #define ZCRYPT_CEX2C            5
 #define ZCRYPT_CEX2A            6
 
+/**
+ * Large random numbers are pulled in 4096 byte chunks from the crypto cards
+ * and stored in a page. Be carefull when increasing this buffer due to size
+ * limitations for AP requests.
+ */
+#define ZCRYPT_RNG_BUFFER_SIZE  4096
+
 struct zcrypt_device;
 
 struct zcrypt_ops {
@@ -107,6 +114,7 @@ struct zcrypt_ops {
         long (*rsa_modexpo_crt)(struct zcrypt_device *,
                                 struct ica_rsa_modexpo_crt *);
         long (*send_cprb)(struct zcrypt_device *, struct ica_xcRB *);
+        long (*rng)(struct zcrypt_device *, char *);
 };
 
 struct zcrypt_device {