s390/zcrypt: Introduce QACT support for AP bus devices.

This patch introduces a new ap_qact() function which
exploits the PQAP(QACT) subfunction. QACT is a new
interface to Query the Ap Compatilibity Type based
on a given AP qid, type, mode and version.

Based on this new function the AP bus scan code is
slightly reworked to use this new interface for
querying the compatible type for each new AP queue
device detected. So new and unknown devices can
get automatically mapped to a compatible type and
handled without the need for toleration patches
for every new hardware.

The currently highest known hardware is CEX6S.
With this patch a possible successor can get
queried for a combatible type known by the device
driver without the need for an toleration patch.

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

1 files changed, 65 insertions, 9 deletions

diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
index 5f0be2040272..0c1c48c476b7 100644
--- a/drivers/s390/crypto/ap_bus.c
+++ b/drivers/s390/crypto/ap_bus.c
@@ -176,6 +176,18 @@ static int ap_apft_available(void)
 	return test_facility(15);
 }
 
+/*
+ * ap_qact_available(): Test if the PQAP(QACT) subfunction is available.
+ *
+ * Returns 1 if the QACT subfunction is available.
+ */
+static inline int ap_qact_available(void)
+{
+	if (ap_configuration)
+		return ap_configuration->qact;
+	return 0;
+}
+
 /**
  * ap_test_queue(): Test adjunct processor queue.
  * @qid: The AP queue number
@@ -988,6 +1000,47 @@ static int ap_select_domain(void)
 }
 
 /*
+ * This function checks the type and returns either 0 for not
+ * supported or the highest compatible type value (which may
+ * include the input type value).
+ */
+static int ap_get_compatible_type(ap_qid_t qid, int rawtype, unsigned int func)
+{
+	int comp_type = 0;
+
+	/* < CEX2A is not supported */
+	if (rawtype < AP_DEVICE_TYPE_CEX2A)
+		return 0;
+	/* up to CEX6 known and fully supported */
+	if (rawtype <= AP_DEVICE_TYPE_CEX6)
+		return rawtype;
+	/*
+	 * unknown new type > CEX6, check for compatibility
+	 * to the highest known and supported type which is
+	 * currently CEX6 with the help of the QACT function.
+	 */
+	if (ap_qact_available()) {
+		struct ap_queue_status status;
+		struct ap_qact_ap_info apinfo = {0};
+
+		apinfo.mode = (func >> 26) & 0x07;
+		apinfo.cat = AP_DEVICE_TYPE_CEX6;
+		status = ap_qact(qid, 0, &apinfo);
+		if (status.response_code == AP_RESPONSE_NORMAL
+		    && apinfo.cat >= AP_DEVICE_TYPE_CEX2A
+		    && apinfo.cat <= AP_DEVICE_TYPE_CEX6)
+			comp_type = apinfo.cat;
+	}
+	if (!comp_type)
+		AP_DBF(DBF_WARN, "queue=%02x.%04x unable to map type %d\n",
+		       AP_QID_CARD(qid), AP_QID_QUEUE(qid), rawtype);
+	else if (comp_type != rawtype)
+		AP_DBF(DBF_INFO, "queue=%02x.%04x map type %d to %d\n",
+		       AP_QID_CARD(qid), AP_QID_QUEUE(qid), rawtype, comp_type);
+	return comp_type;
+}
+
+/*
  * helper function to be used with bus_find_dev
  * matches for the card device with the given id
  */
@@ -1014,8 +1067,8 @@ static void ap_scan_bus(struct work_struct *unused)
 	struct ap_card *ac;
 	struct device *dev;
 	ap_qid_t qid;
-	int depth = 0, type = 0;
-	unsigned int functions = 0;
+	int comp_type, depth = 0, type = 0;
+	unsigned int func = 0;
 	int rc, id, dom, borked, domains, defdomdevs = 0;
 
 	AP_DBF(DBF_DEBUG, "ap_scan_bus running\n");
@@ -1066,12 +1119,12 @@ static void ap_scan_bus(struct work_struct *unused)
 				}
 				continue;
 			}
-			rc = ap_query_queue(qid, &depth, &type, &functions);
+			rc = ap_query_queue(qid, &depth, &type, &func);
 			if (dev) {
 				spin_lock_bh(&aq->lock);
 				if (rc == -ENODEV ||
 				    /* adapter reconfiguration */
-				    (ac && ac->functions != functions))
+				    (ac && ac->functions != func))
 					aq->state = AP_STATE_BORKED;
 				borked = aq->state == AP_STATE_BORKED;
 				spin_unlock_bh(&aq->lock);
@@ -1087,11 +1140,14 @@ static void ap_scan_bus(struct work_struct *unused)
 			}
 			if (rc)
 				continue;
-			/* new queue device needed */
+			/* a new queue device is needed, check out comp type */
+			comp_type = ap_get_compatible_type(qid, type, func);
+			if (!comp_type)
+				continue;
+			/* maybe a card device needs to be created first */
 			if (!ac) {
-				/* but first create the card device */
-				ac = ap_card_create(id, depth,
-						    type, functions);
+				ac = ap_card_create(id, depth, type,
+						    comp_type, func);
 				if (!ac)
 					continue;
 				ac->ap_dev.device.bus = &ap_bus_type;
@@ -1109,7 +1165,7 @@ static void ap_scan_bus(struct work_struct *unused)
 				get_device(&ac->ap_dev.device);
 			}
 			/* now create the new queue device */
-			aq = ap_queue_create(qid, type);
+			aq = ap_queue_create(qid, comp_type);
 			if (!aq)
 				continue;
 			aq->card = ac;