s390/ap: filter ap card functions, new queue functions attribute

With SE SB (Secure Binding) some currently unused and thus always
zero bits in the TAPQ GR2 result are now used to show the binding
state of a queue. So to check if a card has changed the comparing
base is exactly this GR2 value shown as 'ap_function' in sysfs
(/sys/devices/ap/cardxx/ap_functions). Now there is some queue
specific info in this info and so a new mask TAPQ_CARD_FUNC_CMP_MASK
is used to filter out only the relevant bits for card compare.

For the same reason now the function bits (including exactly this
bind/associate information) need to be exposed to user space now.
So tools like lszcrypt can evaluate binding/association state on a
queue base. So here comes a new sysfs attribute

  /sys/devices/ap/cardxx/xx.yyyy/ap_functions

This sysfs attribute is similar to the already existing
ap_functions attribute at ap card level. It shows the
upper 32 bits of GR2 from an invocation of TAPQ for this
AP queue.
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>

drivers/s390/crypto/ap_bus.c

@@ -1999,7 +1999,6 @@ static inline void ap_scan_adapter(int ap)
 		}
 		return;
 	}
-
 	if (ac) {
 		/* Check APQN against existing card device for changes */
 		if (ac->raw_hwtype != type) {
@@ -2008,9 +2007,10 @@ static inline void ap_scan_adapter(int ap)
 			ap_scan_rm_card_dev_and_queue_devs(ac);
 			put_device(dev);
 			ac = NULL;
-		} else if (ac->functions != func) {
+		} else if ((ac->functions & TAPQ_CARD_FUNC_CMP_MASK) !=
+			   (func & TAPQ_CARD_FUNC_CMP_MASK)) {
 			AP_DBF_INFO("%s(%d) functions 0x%08x changed, rm card and queue devs\n",
-				    __func__, ap, type);
+				    __func__, ap, func);
 			ap_scan_rm_card_dev_and_queue_devs(ac);
 			put_device(dev);
 			ac = NULL;

drivers/s390/crypto/ap_bus.h

@@ -178,7 +178,7 @@ struct ap_device {
 struct ap_card {
 	struct ap_device ap_dev;
 	int raw_hwtype;			/* AP raw hardware type. */
-	unsigned int functions;		/* AP device function bitfield. */
+	unsigned int functions;		/* TAPQ GR2 upper 32 facility bits */
 	int queue_depth;		/* AP queue depth.*/
 	int id;				/* AP card number. */
 	unsigned int maxmsgsize;	/* AP msg limit for this card */
@@ -187,6 +187,8 @@ struct ap_card {
 	atomic64_t total_request_count;	/* # requests ever for this AP device.*/
 };
 
+#define TAPQ_CARD_FUNC_CMP_MASK 0xFFFF0000
+
 #define to_ap_card(x) container_of((x), struct ap_card, ap_dev.device)
 
 struct ap_queue {

drivers/s390/crypto/ap_queue.c

@@ -630,6 +630,26 @@ static ssize_t chkstop_show(struct device *dev,
 
 static DEVICE_ATTR_RO(chkstop);
 
+static ssize_t ap_functions_show(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct ap_queue *aq = to_ap_queue(dev);
+	struct ap_queue_status status;
+	struct ap_tapq_gr2 info;
+
+	status = ap_test_queue(aq->qid, 1, &info);
+	if (status.response_code > AP_RESPONSE_BUSY) {
+		AP_DBF_DBG("%s RC 0x%02x on tapq(0x%02x.%04x)\n",
+			   __func__, status.response_code,
+			   AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));
+		return -EIO;
+	}
+
+	return sysfs_emit(buf, "0x%08X\n", info.fac);
+}
+
+static DEVICE_ATTR_RO(ap_functions);
+
 #ifdef CONFIG_ZCRYPT_DEBUG
 static ssize_t states_show(struct device *dev,
 			   struct device_attribute *attr, char *buf)
@@ -738,6 +758,7 @@ static struct attribute *ap_queue_dev_attrs[] = {
 	&dev_attr_interrupt.attr,
 	&dev_attr_config.attr,
 	&dev_attr_chkstop.attr,
+	&dev_attr_ap_functions.attr,
 #ifdef CONFIG_ZCRYPT_DEBUG
 	&dev_attr_states.attr,
 	&dev_attr_last_err_rc.attr,