s390/ap: rework crypto config info and default domain code

Rework of the QCI crypto info and how it is used.
This is only a internal rework but does not affect the way
how the ap bus acts with ap card and queue devices and
domain handling.

Tested on z15, z14, z12 (QCI support) and z196 (no QCI support).
Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

drivers/s390/crypto/ap_bus.c

@@ -73,8 +73,7 @@ EXPORT_SYMBOL(ap_perms);
 DEFINE_MUTEX(ap_perms_mutex);
 EXPORT_SYMBOL(ap_perms_mutex);
 
-static struct ap_config_info *ap_configuration;
-static bool initialised;
+static struct ap_config_info *ap_qci_info;
 
 /*
  * AP bus related debug feature things.
@@ -105,8 +104,10 @@ static struct hrtimer ap_poll_timer;
  */
 static unsigned long long poll_timeout = 250000;
 
-/* Maximum domain id */
-static int ap_max_domain_id;
+/* Maximum domain id, if not given via qci */
+static int ap_max_domain_id = 15;
+/* Maximum adapter id, if not given via qci */
+static int ap_max_adapter_id = 63;
 
 static struct bus_type ap_bus_type;
 
@@ -154,12 +155,12 @@ static int ap_interrupts_available(void)
 }
 
 /**
- * ap_configuration_available(): Test if AP configuration
- * information is available.
+ * ap_qci_available(): Test if AP configuration
+ * information can be queried via QCI subfunction.
  *
- * Returns 1 if AP configuration information is available.
+ * Returns 1 if subfunction PQAP(QCI) is available.
  */
-static int ap_configuration_available(void)
+static int ap_qci_available(void)
 {
 	return test_facility(12);
 }
@@ -182,22 +183,22 @@ static int ap_apft_available(void)
  */
 static inline int ap_qact_available(void)
 {
-	if (ap_configuration)
-		return ap_configuration->qact;
+	if (ap_qci_info)
+		return ap_qci_info->qact;
 	return 0;
 }
 
 /*
- * ap_query_configuration(): Fetch cryptographic config info
+ * ap_fetch_qci_info(): Fetch cryptographic config info
  *
  * Returns the ap configuration info fetched via PQAP(QCI).
  * On success 0 is returned, on failure a negative errno
  * is returned, e.g. if the PQAP(QCI) instruction is not
  * available, the return value will be -EOPNOTSUPP.
  */
-static inline int ap_query_configuration(struct ap_config_info *info)
+static inline int ap_fetch_qci_info(struct ap_config_info *info)
 {
-	if (!ap_configuration_available())
+	if (!ap_qci_available())
 		return -EOPNOTSUPP;
 	if (!info)
 		return -EINVAL;
@@ -205,21 +206,40 @@ static inline int ap_query_configuration(struct ap_config_info *info)
 }
 
 /**
- * ap_init_configuration(): Allocate and query configuration array.
+ * ap_init_qci_info(): Allocate and query qci config info.
+ * Does also update the static variables ap_max_domain_id
+ * and ap_max_adapter_id if this info is available.
+
  */
-static void ap_init_configuration(void)
+static void __init ap_init_qci_info(void)
 {
-	if (!ap_configuration_available())
+	if (!ap_qci_available()) {
+		AP_DBF(DBF_INFO, "%s QCI not supported\n", __func__);
 		return;
+	}
 
-	ap_configuration = kzalloc(sizeof(*ap_configuration), GFP_KERNEL);
-	if (!ap_configuration)
+	ap_qci_info = kzalloc(sizeof(*ap_qci_info), GFP_KERNEL);
+	if (!ap_qci_info)
 		return;
-	if (ap_query_configuration(ap_configuration) != 0) {
-		kfree(ap_configuration);
-		ap_configuration = NULL;
+	if (ap_fetch_qci_info(ap_qci_info) != 0) {
+		kfree(ap_qci_info);
+		ap_qci_info = NULL;
 		return;
 	}
+	AP_DBF(DBF_INFO, "%s successful fetched initial qci info\n", __func__);
+
+	if (ap_qci_info->apxa) {
+		if (ap_qci_info->Na) {
+			ap_max_adapter_id = ap_qci_info->Na;
+			AP_DBF(DBF_INFO, "%s new ap_max_adapter_id is %d\n",
+			       __func__, ap_max_adapter_id);
+		}
+		if (ap_qci_info->Nd) {
+			ap_max_domain_id = ap_qci_info->Nd;
+			AP_DBF(DBF_INFO, "%s new ap_max_domain_id is %d\n",
+			       __func__, ap_max_domain_id);
+		}
+	}
 }
 
 /*
@@ -233,7 +253,6 @@ static inline int ap_test_config(unsigned int *field, unsigned int nr)
 
 /*
  * ap_test_config_card_id(): Test, whether an AP card ID is configured.
- * @id AP card ID
  *
  * Returns 0 if the card is not configured
  *	   1 if the card is configured or
@@ -241,16 +260,16 @@ static inline int ap_test_config(unsigned int *field, unsigned int nr)
  */
 static inline int ap_test_config_card_id(unsigned int id)
 {
-	if (!ap_configuration)	/* QCI not supported */
-		/* only ids 0...3F may be probed */
-		return id < 0x40 ? 1 : 0;
-	return ap_test_config(ap_configuration->apm, id);
+	if (id > ap_max_adapter_id)
+		return 0;
+	if (ap_qci_info)
+		return ap_test_config(ap_qci_info->apm, id);
+	return 1;
 }
 
 /*
  * ap_test_config_usage_domain(): Test, whether an AP usage domain
  * is configured.
- * @domain AP usage domain ID
  *
  * Returns 0 if the usage domain is not configured
  *	   1 if the usage domain is configured or
@@ -258,9 +277,11 @@ static inline int ap_test_config_card_id(unsigned int id)
  */
 int ap_test_config_usage_domain(unsigned int domain)
 {
-	if (!ap_configuration)	/* QCI not supported */
-		return domain < 16;
-	return ap_test_config(ap_configuration->aqm, domain);
+	if (domain > ap_max_domain_id)
+		return 0;
+	if (ap_qci_info)
+		return ap_test_config(ap_qci_info->aqm, domain);
+	return 1;
 }
 EXPORT_SYMBOL(ap_test_config_usage_domain);
 
@@ -274,43 +295,44 @@ EXPORT_SYMBOL(ap_test_config_usage_domain);
  */
 int ap_test_config_ctrl_domain(unsigned int domain)
 {
-	if (!ap_configuration)	/* QCI not supported */
+	if (!ap_qci_info || domain > ap_max_domain_id)
 		return 0;
-	return ap_test_config(ap_configuration->adm, domain);
+	return ap_test_config(ap_qci_info->adm, domain);
 }
 EXPORT_SYMBOL(ap_test_config_ctrl_domain);
 
-/**
- * ap_query_queue(): Check if an AP queue is available.
- * @qid: The AP queue number
- * @queue_depth: Pointer to queue depth value
- * @device_type: Pointer to device type value
- * @facilities: Pointer to facility indicator
+/*
+ * ap_queue_info(): Check and get AP queue info.
+ * Returns true if TAPQ succeeded and the info is filled or
+ * false otherwise.
  */
-static int ap_query_queue(ap_qid_t qid, int *queue_depth, int *device_type,
-			  unsigned int *facilities)
+static bool ap_queue_info(ap_qid_t qid, int *q_type,
+			  unsigned int *q_fac, int *q_depth)
 {
 	struct ap_queue_status status;
-	unsigned long info;
-	int nd;
+	unsigned long info = 0;
 
-	if (!ap_test_config_card_id(AP_QID_CARD(qid)))
-		return -ENODEV;
+	/* make sure we don't run into a specifiation exception */
+	if (AP_QID_CARD(qid) > ap_max_adapter_id ||
+	    AP_QID_QUEUE(qid) > ap_max_domain_id)
+		return false;
 
+	/* call TAPQ on this APQN */
 	status = ap_test_queue(qid, ap_apft_available(), &info);
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
-		*queue_depth = (int)(info & 0xff);
-		*device_type = (int)((info >> 24) & 0xff);
-		*facilities = (unsigned int)(info >> 32);
-		/* Update maximum domain id */
-		nd = (info >> 16) & 0xff;
-		/* if N bit is available, z13 and newer */
-		if ((info & (1UL << 57)) && nd > 0)
-			ap_max_domain_id = nd;
-		else /* older machine types */
-			ap_max_domain_id = 15;
-		switch (*device_type) {
+	case AP_RESPONSE_RESET_IN_PROGRESS:
+		/*
+		 * According to the architecture in all these cases the
+		 * info should be filled. All bits 0 is not possible as
+		 * there is at least one of the mode bits set.
+		 */
+		if (WARN_ON_ONCE(!info))
+			return false;
+		*q_type = (int)((info >> 24) & 0xff);
+		*q_fac = (unsigned int)(info >> 32);
+		*q_depth = (int)(info & 0xff);
+		switch (*q_type) {
 			/* For CEX2 and CEX3 the available functions
 			 * are not reflected by the facilities bits.
 			 * Instead it is coded into the type. So here
@@ -318,27 +340,21 @@ static int ap_query_queue(ap_qid_t qid, int *queue_depth, int *device_type,
 			 */
 		case AP_DEVICE_TYPE_CEX2A:
 		case AP_DEVICE_TYPE_CEX3A:
-			*facilities |= 0x08000000;
+			*q_fac |= 0x08000000;
 			break;
 		case AP_DEVICE_TYPE_CEX2C:
 		case AP_DEVICE_TYPE_CEX3C:
-			*facilities |= 0x10000000;
+			*q_fac |= 0x10000000;
 			break;
 		default:
 			break;
 		}
-		return 0;
-	case AP_RESPONSE_Q_NOT_AVAIL:
-	case AP_RESPONSE_DECONFIGURED:
-	case AP_RESPONSE_CHECKSTOPPED:
-	case AP_RESPONSE_INVALID_ADDRESS:
-		return -ENODEV;
-	case AP_RESPONSE_RESET_IN_PROGRESS:
-	case AP_RESPONSE_OTHERWISE_CHANGED:
-	case AP_RESPONSE_BUSY:
-		return -EBUSY;
+		return true;
 	default:
-		BUG();
+		/*
+		 * A response code which indicates, there is no info available.
+		 */
+		return false;
 	}
 }
 
@@ -751,9 +767,6 @@ int ap_driver_register(struct ap_driver *ap_drv, struct module *owner,
 {
 	struct device_driver *drv = &ap_drv->driver;
 
-	if (!initialised)
-		return -ENODEV;
-
 	drv->bus = &ap_bus_type;
 	drv->probe = ap_device_probe;
 	drv->remove = ap_device_remove;
@@ -929,11 +942,12 @@ static ssize_t ap_domain_store(struct bus_type *bus,
 	    domain < 0 || domain > ap_max_domain_id ||
 	    !test_bit_inv(domain, ap_perms.aqm))
 		return -EINVAL;
+
 	spin_lock_bh(&ap_domain_lock);
 	ap_domain_index = domain;
 	spin_unlock_bh(&ap_domain_lock);
 
-	AP_DBF(DBF_DEBUG, "stored new default domain=%d\n", domain);
+	AP_DBF(DBF_INFO, "stored new default domain=%d\n", domain);
 
 	return count;
 }
@@ -942,45 +956,45 @@ static BUS_ATTR_RW(ap_domain);
 
 static ssize_t ap_control_domain_mask_show(struct bus_type *bus, char *buf)
 {
-	if (!ap_configuration)	/* QCI not supported */
+	if (!ap_qci_info)	/* QCI not supported */
 		return scnprintf(buf, PAGE_SIZE, "not supported\n");
 
 	return scnprintf(buf, PAGE_SIZE,
 			 "0x%08x%08x%08x%08x%08x%08x%08x%08x\n",
-			 ap_configuration->adm[0], ap_configuration->adm[1],
-			 ap_configuration->adm[2], ap_configuration->adm[3],
-			 ap_configuration->adm[4], ap_configuration->adm[5],
-			 ap_configuration->adm[6], ap_configuration->adm[7]);
+			 ap_qci_info->adm[0], ap_qci_info->adm[1],
+			 ap_qci_info->adm[2], ap_qci_info->adm[3],
+			 ap_qci_info->adm[4], ap_qci_info->adm[5],
+			 ap_qci_info->adm[6], ap_qci_info->adm[7]);
 }
 
 static BUS_ATTR_RO(ap_control_domain_mask);
 
 static ssize_t ap_usage_domain_mask_show(struct bus_type *bus, char *buf)
 {
-	if (!ap_configuration)	/* QCI not supported */
+	if (!ap_qci_info)	/* QCI not supported */
 		return scnprintf(buf, PAGE_SIZE, "not supported\n");
 
 	return scnprintf(buf, PAGE_SIZE,
 			 "0x%08x%08x%08x%08x%08x%08x%08x%08x\n",
-			 ap_configuration->aqm[0], ap_configuration->aqm[1],
-			 ap_configuration->aqm[2], ap_configuration->aqm[3],
-			 ap_configuration->aqm[4], ap_configuration->aqm[5],
-			 ap_configuration->aqm[6], ap_configuration->aqm[7]);
+			 ap_qci_info->aqm[0], ap_qci_info->aqm[1],
+			 ap_qci_info->aqm[2], ap_qci_info->aqm[3],
+			 ap_qci_info->aqm[4], ap_qci_info->aqm[5],
+			 ap_qci_info->aqm[6], ap_qci_info->aqm[7]);
 }
 
 static BUS_ATTR_RO(ap_usage_domain_mask);
 
 static ssize_t ap_adapter_mask_show(struct bus_type *bus, char *buf)
 {
-	if (!ap_configuration)	/* QCI not supported */
+	if (!ap_qci_info)	/* QCI not supported */
 		return scnprintf(buf, PAGE_SIZE, "not supported\n");
 
 	return scnprintf(buf, PAGE_SIZE,
 			 "0x%08x%08x%08x%08x%08x%08x%08x%08x\n",
-			 ap_configuration->apm[0], ap_configuration->apm[1],
-			 ap_configuration->apm[2], ap_configuration->apm[3],
-			 ap_configuration->apm[4], ap_configuration->apm[5],
-			 ap_configuration->apm[6], ap_configuration->apm[7]);
+			 ap_qci_info->apm[0], ap_qci_info->apm[1],
+			 ap_qci_info->apm[2], ap_qci_info->apm[3],
+			 ap_qci_info->apm[4], ap_qci_info->apm[5],
+			 ap_qci_info->apm[6], ap_qci_info->apm[7]);
 }
 
 static BUS_ATTR_RO(ap_adapter_mask);
@@ -1066,17 +1080,18 @@ static BUS_ATTR_RW(poll_timeout);
 
 static ssize_t ap_max_domain_id_show(struct bus_type *bus, char *buf)
 {
-	int max_domain_id;
-
-	if (ap_configuration)
-		max_domain_id = ap_max_domain_id ? : -1;
-	else
-		max_domain_id = 15;
-	return scnprintf(buf, PAGE_SIZE, "%d\n", max_domain_id);
+	return scnprintf(buf, PAGE_SIZE, "%d\n", ap_max_domain_id);
 }
 
 static BUS_ATTR_RO(ap_max_domain_id);
 
+static ssize_t ap_max_adapter_id_show(struct bus_type *bus, char *buf)
+{
+	return scnprintf(buf, PAGE_SIZE, "%d\n", ap_max_adapter_id);
+}
+
+static BUS_ATTR_RO(ap_max_adapter_id);
+
 static ssize_t apmask_show(struct bus_type *bus, char *buf)
 {
 	int rc;
@@ -1149,6 +1164,7 @@ static struct bus_attribute *const ap_bus_attrs[] = {
 	&bus_attr_ap_interrupts,
 	&bus_attr_poll_timeout,
 	&bus_attr_ap_max_domain_id,
+	&bus_attr_ap_max_adapter_id,
 	&bus_attr_apmask,
 	&bus_attr_aqmask,
 	NULL,
@@ -1160,47 +1176,42 @@ static struct bus_attribute *const ap_bus_attrs[] = {
  */
 static void ap_select_domain(void)
 {
-	int count, max_count, best_domain;
 	struct ap_queue_status status;
-	int i, j;
+	int card, dom;
 
 	/*
-	 * We want to use a single domain. Either the one specified with
-	 * the "domain=" parameter or the domain with the maximum number
-	 * of devices.
+	 * Choose the default domain. Either the one specified with
+	 * the "domain=" parameter or the first domain with at least
+	 * one valid APQN.
 	 */
 	spin_lock_bh(&ap_domain_lock);
 	if (ap_domain_index >= 0) {
 		/* Domain has already been selected. */
-		spin_unlock_bh(&ap_domain_lock);
-		return;
+		goto out;
 	}
-	best_domain = -1;
-	max_count = 0;
-	for (i = 0; i < AP_DOMAINS; i++) {
-		if (!ap_test_config_usage_domain(i) ||
-		    !test_bit_inv(i, ap_perms.aqm))
+	for (dom = 0; dom <= ap_max_domain_id; dom++) {
+		if (!ap_test_config_usage_domain(dom) ||
+		    !test_bit_inv(dom, ap_perms.aqm))
 			continue;
-		count = 0;
-		for (j = 0; j < AP_DEVICES; j++) {
-			if (!ap_test_config_card_id(j))
+		for (card = 0; card <= ap_max_adapter_id; card++) {
+			if (!ap_test_config_card_id(card) ||
+			    !test_bit_inv(card, ap_perms.apm))
 				continue;
-			status = ap_test_queue(AP_MKQID(j, i),
+			status = ap_test_queue(AP_MKQID(card, dom),
 					       ap_apft_available(),
 					       NULL);
-			if (status.response_code != AP_RESPONSE_NORMAL)
-				continue;
-			count++;
-		}
-		if (count > max_count) {
-			max_count = count;
-			best_domain = i;
+			if (status.response_code == AP_RESPONSE_NORMAL)
+				break;
 		}
+		if (card <= ap_max_adapter_id)
+			break;
 	}
-	if (best_domain >= 0) {
-		ap_domain_index = best_domain;
-		AP_DBF(DBF_DEBUG, "new ap_domain_index=%d\n", ap_domain_index);
+	if (dom <= ap_max_domain_id) {
+		ap_domain_index = dom;
+		AP_DBF(DBF_DEBUG, "%s new default domain is %d\n",
+		       __func__, ap_domain_index);
 	}
+out:
 	spin_unlock_bh(&ap_domain_lock);
 }
 
@@ -1279,12 +1290,13 @@ static int __match_queue_device_with_queue_id(struct device *dev, const void *da
  */
 static void _ap_scan_bus_adapter(int id)
 {
+	bool broken;
 	ap_qid_t qid;
 	unsigned int func;
 	struct ap_card *ac;
 	struct device *dev;
 	struct ap_queue *aq;
-	int rc, dom, depth, type, comp_type, borked;
+	int rc, dom, depth, type, comp_type;
 
 	/* check if there is a card device registered with this id */
 	dev = bus_find_device(&ap_bus_type, NULL,
@@ -1312,23 +1324,23 @@ static void _ap_scan_bus_adapter(int id)
 		/* find the first valid queue */
 		for (dom = 0; dom < AP_DOMAINS; dom++) {
 			qid = AP_MKQID(id, dom);
-			if (ap_query_queue(qid, &depth, &type, &func) == 0)
+			if (ap_queue_info(qid, &type, &func, &depth))
 				break;
 		}
-		borked = 0;
+		broken = false;
 		if (dom >= AP_DOMAINS) {
 			/* no accessible queue on this card */
-			borked = 1;
+			broken = true;
 		} else if (ac->raw_hwtype != type) {
 			/* card type has changed */
 			AP_DBF(DBF_INFO, "card=%02x type changed.\n", id);
-			borked = 1;
+			broken = true;
 		} else if (ac->functions != func) {
 			/* card functions have changed */
 			AP_DBF(DBF_INFO, "card=%02x functions changed.\n", id);
-			borked = 1;
+			broken = true;
 		}
-		if (borked) {
+		if (broken) {
 			/* unregister card device and associated queues */
 			bus_for_each_dev(&ap_bus_type, NULL,
 					 (void *)(long) id,
@@ -1364,16 +1376,14 @@ static void _ap_scan_bus_adapter(int id)
 			continue;
 		}
 		/* try to fetch infos about this queue */
-		rc = ap_query_queue(qid, &depth, &type, &func);
+		broken = !ap_queue_info(qid, &type, &func, &depth);
 		if (dev) {
-			if (rc == -ENODEV)
-				borked = 1;
-			else {
+			if (!broken) {
 				spin_lock_bh(&aq->lock);
-				borked = aq->sm_state == AP_SM_STATE_BORKED;
+				broken = aq->sm_state == AP_SM_STATE_BORKED;
 				spin_unlock_bh(&aq->lock);
 			}
-			if (borked) {
+			if (broken) {
 				/* Remove broken device */
 				AP_DBF(DBF_DEBUG,
 				       "removing broken queue=%02x.%04x\n",
@@ -1383,7 +1393,7 @@ static void _ap_scan_bus_adapter(int id)
 			put_device(dev);
 			continue;
 		}
-		if (rc)
+		if (broken)
 			continue;
 		/* a new queue device is needed, check out comp type */
 		comp_type = ap_get_compatible_type(qid, type, func);
@@ -1435,11 +1445,11 @@ static void ap_scan_bus(struct work_struct *unused)
 {
 	int id;
 
-	AP_DBF(DBF_DEBUG, "%s running\n", __func__);
-
-	ap_query_configuration(ap_configuration);
+	ap_fetch_qci_info(ap_qci_info);
 	ap_select_domain();
 
+	AP_DBF(DBF_DEBUG, "%s running\n", __func__);
+
 	/* loop over all possible adapters */
 	for (id = 0; id < AP_DEVICES; id++)
 		_ap_scan_bus_adapter(id);
@@ -1505,7 +1515,6 @@ static void __init ap_perms_init(void)
  */
 static int __init ap_module_init(void)
 {
-	int max_domain_id;
 	int rc, i;
 
 	rc = ap_debug_init();
@@ -1524,14 +1533,10 @@ static int __init ap_module_init(void)
 	ap_perms_init();
 
 	/* Get AP configuration data if available */
-	ap_init_configuration();
+	ap_init_qci_info();
 
-	if (ap_configuration)
-		max_domain_id =
-			ap_max_domain_id ? ap_max_domain_id : AP_DOMAINS - 1;
-	else
-		max_domain_id = 15;
-	if (ap_domain_index < -1 || ap_domain_index > max_domain_id ||
+	/* check default domain setting */
+	if (ap_domain_index < -1 || ap_domain_index > ap_max_domain_id ||
 	    (ap_domain_index >= 0 &&
 	     !test_bit_inv(ap_domain_index, ap_perms.aqm))) {
 		pr_warn("%d is not a valid cryptographic domain\n",
@@ -1539,6 +1544,7 @@ static int __init ap_module_init(void)
 		ap_domain_index = -1;
 	}
 
+	/* enable interrupts if available */
 	if (ap_interrupts_available()) {
 		rc = register_adapter_interrupt(&ap_airq);
 		ap_airq_flag = (rc == 0);
@@ -1581,7 +1587,6 @@ static int __init ap_module_init(void)
 	}
 
 	queue_work(system_long_wq, &ap_scan_work);
-	initialised = true;
 
 	return 0;
 
@@ -1595,7 +1600,7 @@ static int __init ap_module_init(void)
 out:
 	if (ap_using_interrupts())
 		unregister_adapter_interrupt(&ap_airq);
-	kfree(ap_configuration);
+	kfree(ap_qci_info);
 	return rc;
 }
 device_initcall(ap_module_init);