s390/ap: add ap status asynch error support

Review and extend the low level AP code to be able to
deal with asynchronous reported errors on APQNs.

The hypervisor and the SE guest may be confronted with
an asynchronously reported error at return of an AP
instruction. So all places where AP instructions are
called need review and may eventually need extensions.
However, not all places need rework. As together with
the AP status and the enabled asynch bit there is always
a response code set. The asynch error reporting comes
with new response codes which may be simple handled in
the default case of a switch statement.

The idea behind this patch is to report asynch errors
as -EPERM (read this as "Operation not permitted") which
reflects the fact that only a rapq (with F bit enabled)
is a valid AP instruction when an asynch error is flagged.

The AP queue state machine functions return
AP_SM_WAIT_NONE when a asynch error is detected to reflect
the fact, that the state machine can't do anything with
such an error as long as the queue is reset.

Unfortunately the ap bus scan function needed some
update as the ap_queue_info() now needs to return
3 states: 1 if an APQN exists and info is available,
-1 if it is assumed an APQN does not exist and the new
return value 0 without any info values filled. This 0
returncode is handled as "there is an APQN but we currently
don't know any more hw info about this, so please use
your previous info and try again later".

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, 12 insertions, 0 deletions

diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c
index 2be63f2554bd..ed8f813653fe 100644
--- a/drivers/s390/crypto/ap_queue.c
+++ b/drivers/s390/crypto/ap_queue.c
@@ -50,6 +50,8 @@ static int ap_queue_enable_irq(struct ap_queue *aq, void *ind)
 	qirqctrl.ir = 1;
 	qirqctrl.isc = AP_ISC;
 	status = ap_aqic(aq->qid, qirqctrl, virt_to_phys(ind));
+	if (status.async)
+		return -EPERM;
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 	case AP_RESPONSE_OTHERWISE_CHANGED:
@@ -96,6 +98,8 @@ 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, msglen, 0);
+	if (status.async)
+		return -EPERM;
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		return 0;
@@ -117,6 +121,8 @@ int ap_recv(ap_qid_t qid, unsigned long *psmid, void *msg, size_t msglen)
 	if (!msg)
 		return -EINVAL;
 	status = ap_dqap(qid, psmid, msg, msglen, NULL, NULL, NULL);
+	if (status.async)
+		return -EPERM;
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		return 0;
@@ -225,6 +231,8 @@ static enum ap_sm_wait ap_sm_read(struct ap_queue *aq)
 	if (!aq->reply)
 		return AP_SM_WAIT_NONE;
 	status = ap_sm_recv(aq);
+	if (status.async)
+		return AP_SM_WAIT_NONE;
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		if (aq->queue_count > 0) {
@@ -276,6 +284,8 @@ static enum ap_sm_wait ap_sm_write(struct ap_queue *aq)
 	status = __ap_send(qid, ap_msg->psmid,
 			   ap_msg->msg, ap_msg->len,
 			   ap_msg->flags & AP_MSG_FLAG_SPECIAL);
+	if (status.async)
+		return AP_SM_WAIT_NONE;
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		aq->queue_count = max_t(int, 1, aq->queue_count + 1);
@@ -338,6 +348,8 @@ static enum ap_sm_wait ap_sm_reset(struct ap_queue *aq)
 	struct ap_queue_status status;
 
 	status = ap_rapq(aq->qid, aq->rapq_fbit);
+	if (status.async)
+		return AP_SM_WAIT_NONE;
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 	case AP_RESPONSE_RESET_IN_PROGRESS: