s390/ap: fix state machine hang after failure to enable irq

If for any reason the interrupt enable for an ap queue fails the
state machine run for the queue returned wrong return codes to the
caller. So the caller assumed interrupt support for this queue in
enabled and thus did not re-establish the high resolution timer used
for polling. In the end this let to a hang for the user space process
waiting "forever" for the reply.

This patch reworks these return codes to return correct indications
for the caller to re-establish the timer when a queue runs without
interrupt support.

Please note that this is fixing a wrong behavior after a first
failure (enable interrupt support for the queue) failed. However,
looks like this occasionally happens on KVM systems.

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

drivers/s390/crypto/ap_bus.h

@@ -80,12 +80,6 @@ static inline int ap_test_bit(unsigned int *ptr, unsigned int nr)
 #define AP_FUNC_EP11  5
 #define AP_FUNC_APXA  6
 
-/*
- * AP interrupt states
- */
-#define AP_INTR_DISABLED	0	/* AP interrupt disabled */
-#define AP_INTR_ENABLED		1	/* AP interrupt enabled */
-
 /*
  * AP queue state machine states
  */
@@ -112,7 +106,7 @@ enum ap_sm_event {
  * AP queue state wait behaviour
  */
 enum ap_sm_wait {
-	AP_SM_WAIT_AGAIN,	/* retry immediately */
+	AP_SM_WAIT_AGAIN = 0,	/* retry immediately */
 	AP_SM_WAIT_TIMEOUT,	/* wait for timeout */
 	AP_SM_WAIT_INTERRUPT,	/* wait for thin interrupt (if available) */
 	AP_SM_WAIT_NONE,	/* no wait */
@@ -183,7 +177,7 @@ struct ap_queue {
 	enum ap_dev_state dev_state;	/* queue device state */
 	bool config;			/* configured state */
 	ap_qid_t qid;			/* AP queue id. */
-	int interrupt;			/* indicate if interrupts are enabled */
+	bool interrupt;			/* indicate if interrupts are enabled */
 	int queue_count;		/* # messages currently on AP queue. */
 	int pendingq_count;		/* # requests on pendingq list. */
 	int requestq_count;		/* # requests on requestq list. */