s390/zcrypt: externalize test AP queue

Under certain specified conditions, the Test AP Queue (TAPQ)
subfunction of the Process Adjunct Processor Queue (PQAP) instruction
will be intercepted by a guest VM. The guest VM must have a means for
executing the intercepted instruction.

The vfio_ap driver will provide an interface to execute the
PQAP(TAPQ) instruction subfunction on behalf of a guest VM.
The code for executing the AP instructions currently resides in the
AP bus. This patch refactors the AP bus code to externalize access
to the PQAP(TAPQ) instruction subfunction to make it available to
the vfio_ap driver.

Signed-off-by: Tony Krowiak <akrowiak@linux.vnet.ibm.com>
Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

3 files changed, 24 insertions, 42 deletions

diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 6dee598979e7..4fcfa8d4e0b5 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -166,19 +166,33 @@ static int ap_configuration_available(void)
 }
 
 /**
+ * ap_apft_available(): Test if AP facilities test (APFT)
+ * facility is available.
+ *
+ * Returns 1 if APFT is is available.
+ */
+static int ap_apft_available(void)
+{
+	return test_facility(15);
+}
+
+/**
  * ap_test_queue(): Test adjunct processor queue.
  * @qid: The AP queue number
+ * @tbit: Test facilities bit
  * @info: Pointer to queue descriptor
  *
  * Returns AP queue status structure.
  */
-static inline struct ap_queue_status
-ap_test_queue(ap_qid_t qid, unsigned long *info)
+struct ap_queue_status ap_test_queue(ap_qid_t qid,
+				     int tbit,
+				     unsigned long *info)
 {
-	if (test_facility(15))
-		qid |= 1UL << 23;		/* set APFT T bit*/
+	if (tbit)
+		qid |= 1UL << 23; /* set T bit*/
 	return ap_tapq(qid, info);
 }
+EXPORT_SYMBOL(ap_test_queue);
 
 static inline int ap_query_configuration(void)
 {
@@ -261,7 +275,7 @@ static int ap_query_queue(ap_qid_t qid, int *queue_depth, int *device_type,
 	if (!ap_test_config_card_id(AP_QID_CARD(qid)))
 		return -ENODEV;
 
-	status = ap_test_queue(qid, &info);
+	status = ap_test_queue(qid, ap_apft_available(), &info);
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		*queue_depth = (int)(info & 0xff);
@@ -940,7 +954,9 @@ static int ap_select_domain(void)
 		for (j = 0; j < AP_DEVICES; j++) {
 			if (!ap_test_config_card_id(j))
 				continue;
-			status = ap_test_queue(AP_MKQID(j, i), NULL);
+			status = ap_test_queue(AP_MKQID(j, i),
+					       ap_apft_available(),
+					       NULL);
 			if (status.response_code != AP_RESPONSE_NORMAL)
 				continue;
 			count++;
diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index 4dc7c88fb054..f07698d41f77 100644
--- a/drivers/s390/crypto/ap_bus.h
+++ b/drivers/s390/crypto/ap_bus.h
@@ -28,6 +28,7 @@
 
 #include <linux/device.h>
 #include <linux/types.h>
+#include <asm/ap.h>
 
 #define AP_DEVICES 64		/* Number of AP devices. */
 #define AP_DOMAINS 256		/* Number of AP domains. */
@@ -40,41 +41,6 @@ extern int ap_domain_index;
 extern spinlock_t ap_list_lock;
 extern struct list_head ap_card_list;
 
-/**
- * The ap_qid_t identifier of an ap queue. It contains a
- * 6 bit card index and a 4 bit queue index (domain).
- */
-typedef unsigned int ap_qid_t;
-
-#define AP_MKQID(_card, _queue) (((_card) & 63) << 8 | ((_queue) & 255))
-#define AP_QID_CARD(_qid) (((_qid) >> 8) & 63)
-#define AP_QID_QUEUE(_qid) ((_qid) & 255)
-
-/**
- * structy ap_queue_status - Holds the AP queue status.
- * @queue_empty: Shows if queue is empty
- * @replies_waiting: Waiting replies
- * @queue_full: Is 1 if the queue is full
- * @pad: A 4 bit pad
- * @int_enabled: Shows if interrupts are enabled for the AP
- * @response_code: Holds the 8 bit response code
- * @pad2: A 16 bit pad
- *
- * The ap queue status word is returned by all three AP functions
- * (PQAP, NQAP and DQAP).  There's a set of flags in the first
- * byte, followed by a 1 byte response code.
- */
-struct ap_queue_status {
-	unsigned int queue_empty	: 1;
-	unsigned int replies_waiting	: 1;
-	unsigned int queue_full		: 1;
-	unsigned int pad1		: 4;
-	unsigned int int_enabled	: 1;
-	unsigned int response_code	: 8;
-	unsigned int pad2		: 16;
-} __packed;
-
-
 static inline int ap_test_bit(unsigned int *ptr, unsigned int nr)
 {
 	return (*ptr & (0x80000000u >> nr)) != 0;
diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c
index 0f1a5d02acb0..c906fb73a215 100644
--- a/drivers/s390/crypto/ap_queue.c
+++ b/drivers/s390/crypto/ap_queue.c
@@ -362,7 +362,7 @@ static enum ap_wait ap_sm_setirq_wait(struct ap_queue *aq)
 		/* Get the status with TAPQ */
 		status = ap_tapq(aq->qid, NULL);
 
-	if (status.int_enabled == 1) {
+	if (status.irq_enabled == 1) {
 		/* Irqs are now enabled */
 		aq->interrupt = AP_INTR_ENABLED;
 		aq->state = (aq->queue_count > 0) ?