s390/zcrypt: Rework cca findcard() implementation and callers

Rework the memory usage of the cca findcard() implementation:
- findcard does not allocate memory for the list of apqns
  any more.
- the callers are now responsible to provide an array of
  apqns to store the matching apqns into.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Link: https://lore.kernel.org/r/20250424133619.16495-14-freude@linux.ibm.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

1 files changed, 5 insertions, 7 deletions

diff --git a/drivers/s390/crypto/zcrypt_ccamisc.h b/drivers/s390/crypto/zcrypt_ccamisc.h
index cc7d362a2bad..ca41a675dd3b 100644
--- a/drivers/s390/crypto/zcrypt_ccamisc.h
+++ b/drivers/s390/crypto/zcrypt_ccamisc.h
@@ -217,14 +217,12 @@ int cca_query_crypto_facility(u16 cardnr, u16 domain,
  * - if old_mkvp != 0 only apqns where old_mkvp == mkvp
  * The mktype determines which set of master keys to use:
  *   0 = AES_MK_SET - AES MK set, 1 = APKA MK_SET - APKA MK set
- * The array of apqn entries is allocated with kmalloc and returned in *apqns;
- * the number of apqns stored into the list is returned in *nr_apqns. One apqn
- * entry is simple a 32 bit value with 16 bit cardnr and 16 bit domain nr and
- * may be casted to struct pkey_apqn. The return value is either 0 for success
- * or a negative errno value. If no apqn meeting the criteria is found,
- * -ENODEV is returned.
+ * The caller should set *nr_apqns to the nr of elements available in *apqns.
+ * On return *nr_apqns is then updated with the nr of apqns filled into *apqns.
+ * The return value is either 0 for success or a negative errno value.
+ * If no apqn meeting the criteria is found, -ENODEV is returned.
  */
-int cca_findcard2(u32 **apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
+int cca_findcard2(u32 *apqns, u32 *nr_apqns, u16 cardnr, u16 domain,
 		  int minhwtype, int mktype, u64 cur_mkvp, u64 old_mkvp);
 
 #define AES_MK_SET  0