s390/zcrypt: rework length information for dqap

The inline ap_dqap function does not return the number of
bytes actually written into the message buffer. The calling
code inspects the AP message header to figure out what kind
of AP message has been received and pulls the length
information from this header. This processing may not work
correctly in cases where only a fragment of the reply is
received.

With this patch the ap_dqap inline function now returns
the number of actually written bytes in the *length parameter.
So the calling function has a chance to compare the number of
received bytes against what the AP message header length
field states. This is especially useful in cases where a
message could only get partially received.

The low level reply processing functions needed some rework
to be able to catch this new length information and compare
it the right way. The rework also deals with some situations
where until now the reply length was not correctly calculated
and/or set.

All this has been heavily tested as the modifications on
the reply length information may affect crypto load.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

1 files changed, 8 insertions, 8 deletions

diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c
index 2fe8cbf72091..bbd314918a5d 100644
--- a/drivers/s390/crypto/ap_queue.c
+++ b/drivers/s390/crypto/ap_queue.c
@@ -59,7 +59,7 @@ static int ap_queue_enable_irq(struct ap_queue *aq, void *ind)
  * @qid: The AP queue number
  * @psmid: The program supplied message identifier
  * @msg: The message text
- * @length: The message length
+ * @msglen: The message length
  * @special: Special Bit
  *
  * Returns AP queue status structure.
@@ -68,19 +68,19 @@ static int ap_queue_enable_irq(struct ap_queue *aq, void *ind)
  * because a segment boundary was reached. The NQAP is repeated.
  */
 static inline struct ap_queue_status
-__ap_send(ap_qid_t qid, unsigned long psmid, void *msg, size_t length,
+__ap_send(ap_qid_t qid, unsigned long psmid, void *msg, size_t msglen,
 	  int special)
 {
 	if (special)
 		qid |= 0x400000UL;
-	return ap_nqap(qid, psmid, msg, length);
+	return ap_nqap(qid, psmid, msg, msglen);
 }
 
-int ap_send(ap_qid_t qid, unsigned long psmid, void *msg, size_t length)
+int ap_send(ap_qid_t qid, unsigned long psmid, void *msg, size_t msglen)
 {
 	struct ap_queue_status status;
 
-	status = __ap_send(qid, psmid, msg, length, 0);
+	status = __ap_send(qid, psmid, msg, msglen, 0);
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		return 0;
@@ -95,13 +95,13 @@ int ap_send(ap_qid_t qid, unsigned long psmid, void *msg, size_t length)
 }
 EXPORT_SYMBOL(ap_send);
 
-int ap_recv(ap_qid_t qid, unsigned long *psmid, void *msg, size_t length)
+int ap_recv(ap_qid_t qid, unsigned long *psmid, void *msg, size_t msglen)
 {
 	struct ap_queue_status status;
 
 	if (!msg)
 		return -EINVAL;
-	status = ap_dqap(qid, psmid, msg, length, NULL, NULL);
+	status = ap_dqap(qid, psmid, msg, msglen, NULL, NULL, NULL);
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		return 0;
@@ -150,7 +150,7 @@ static struct ap_queue_status ap_sm_recv(struct ap_queue *aq)
 	do {
 		status = ap_dqap(aq->qid, &aq->reply->psmid,
 				 aq->reply->msg, aq->reply->bufsize,
-				 &reslen, &resgr0);
+				 &aq->reply->len, &reslen, &resgr0);
 		parts++;
 	} while (status.response_code == 0xFF && resgr0 != 0);