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authorHarald Freudenberger <freude@linux.ibm.com>2021-06-30 17:10:56 +0300
committerVasily Gorbik <gor@linux.ibm.com>2021-07-08 16:37:27 +0300
commit1f0d22defd59f603d63ba51483eeb8d72726ce8b (patch)
tree2d5596036c3cdb260d56cc3b7902490f72ba25a2 /drivers
parentbd39654a2282c1a51c044575a6bc00d641d5dfd1 (diff)
downloadlinux-1f0d22defd59f603d63ba51483eeb8d72726ce8b.tar.xz
s390/ap: Rework ap_dqap to deal with messages greater than recv buffer
Rework of the ap_dqap() inline function with the dqap inline assembler invocation and the caller code in ap_queue.c to be able to handle replies which exceed the receive buffer size. ap_dqap() now provides two additional parameters to handle together with the caller the case where a reply in the firmware queue entry exceeds the given message buffer size. It depends on the caller how to exactly handle this. The behavior implemented now by ap_sm_recv() in ap_queue.c is to simple purge this entry from the firmware queue and let the caller 'receive' a -EMSGSIZE for the request without delivering any reply data - not even a truncated reply message. However, the reworked ap_dqap() could now get invoked in a way that the message is received in multiple parts and the caller assembles the parts into one reply message. Signed-off-by: Harald Freudenberger <freude@linux.ibm.com> Suggested-by: Juergen Christ <jchrist@linux.ibm.com> Reviewed-by: Juergen Christ <jchrist@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/s390/crypto/ap_queue.c28
1 files changed, 24 insertions, 4 deletions
diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c
index c5e0fe0286e5..669f96fddad6 100644
--- a/drivers/s390/crypto/ap_queue.c
+++ b/drivers/s390/crypto/ap_queue.c
@@ -101,7 +101,7 @@ int ap_recv(ap_qid_t qid, unsigned long long *psmid, void *msg, size_t length)
if (msg == NULL)
return -EINVAL;
- status = ap_dqap(qid, psmid, msg, length);
+ status = ap_dqap(qid, psmid, msg, length, NULL, NULL);
switch (status.response_code) {
case AP_RESPONSE_NORMAL:
return 0;
@@ -136,9 +136,24 @@ static struct ap_queue_status ap_sm_recv(struct ap_queue *aq)
struct ap_queue_status status;
struct ap_message *ap_msg;
bool found = false;
+ size_t reslen;
+ unsigned long resgr0 = 0;
+ int parts = 0;
+
+ /*
+ * DQAP loop until response code and resgr0 indicate that
+ * the msg is totally received. As we use the very same buffer
+ * the msg is overwritten with each invocation. That's intended
+ * and the receiver of the msg is informed with a msg rc code
+ * of EMSGSIZE in such a case.
+ */
+ do {
+ status = ap_dqap(aq->qid, &aq->reply->psmid,
+ aq->reply->msg, aq->reply->bufsize,
+ &reslen, &resgr0);
+ parts++;
+ } while (status.response_code == 0xFF && resgr0 != 0);
- status = ap_dqap(aq->qid, &aq->reply->psmid,
- aq->reply->msg, aq->reply->bufsize);
switch (status.response_code) {
case AP_RESPONSE_NORMAL:
aq->queue_count = max_t(int, 0, aq->queue_count - 1);
@@ -150,7 +165,12 @@ static struct ap_queue_status ap_sm_recv(struct ap_queue *aq)
continue;
list_del_init(&ap_msg->list);
aq->pendingq_count--;
- ap_msg->receive(aq, ap_msg, aq->reply);
+ if (parts > 1) {
+ ap_msg->rc = -EMSGSIZE;
+ ap_msg->receive(aq, ap_msg, NULL);
+ } else {
+ ap_msg->receive(aq, ap_msg, aq->reply);
+ }
found = true;
break;
}