Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2278 insertions, 0 deletions

diff --git a/drivers/s390/crypto/ap_bus.c b/drivers/s390/crypto/ap_bus.c
new file mode 100644
index 000000000..4c0f9fe1b
--- /dev/null
+++ b/drivers/s390/crypto/ap_bus.c
@@ -0,0 +1,2278 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright IBM Corp. 2006, 2021
+ * Author(s): Cornelia Huck <cornelia.huck@de.ibm.com>
+ *	      Martin Schwidefsky <schwidefsky@de.ibm.com>
+ *	      Ralph Wuerthner <rwuerthn@de.ibm.com>
+ *	      Felix Beck <felix.beck@de.ibm.com>
+ *	      Holger Dengler <hd@linux.vnet.ibm.com>
+ *	      Harald Freudenberger <freude@linux.ibm.com>
+ *
+ * Adjunct processor bus.
+ */
+
+#define KMSG_COMPONENT "ap"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/kernel_stat.h>
+#include <linux/moduleparam.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/freezer.h>
+#include <linux/interrupt.h>
+#include <linux/workqueue.h>
+#include <linux/slab.h>
+#include <linux/notifier.h>
+#include <linux/kthread.h>
+#include <linux/mutex.h>
+#include <asm/airq.h>
+#include <asm/tpi.h>
+#include <linux/atomic.h>
+#include <asm/isc.h>
+#include <linux/hrtimer.h>
+#include <linux/ktime.h>
+#include <asm/facility.h>
+#include <linux/crypto.h>
+#include <linux/mod_devicetable.h>
+#include <linux/debugfs.h>
+#include <linux/ctype.h>
+#include <linux/module.h>
+
+#include "ap_bus.h"
+#include "ap_debug.h"
+
+/*
+ * Module parameters; note though this file itself isn't modular.
+ */
+int ap_domain_index = -1;	/* Adjunct Processor Domain Index */
+static DEFINE_SPINLOCK(ap_domain_lock);
+module_param_named(domain, ap_domain_index, int, 0440);
+MODULE_PARM_DESC(domain, "domain index for ap devices");
+EXPORT_SYMBOL(ap_domain_index);
+
+static int ap_thread_flag;
+module_param_named(poll_thread, ap_thread_flag, int, 0440);
+MODULE_PARM_DESC(poll_thread, "Turn on/off poll thread, default is 0 (off).");
+
+static char *apm_str;
+module_param_named(apmask, apm_str, charp, 0440);
+MODULE_PARM_DESC(apmask, "AP bus adapter mask.");
+
+static char *aqm_str;
+module_param_named(aqmask, aqm_str, charp, 0440);
+MODULE_PARM_DESC(aqmask, "AP bus domain mask.");
+
+static int ap_useirq = 1;
+module_param_named(useirq, ap_useirq, int, 0440);
+MODULE_PARM_DESC(useirq, "Use interrupt if available, default is 1 (on).");
+
+atomic_t ap_max_msg_size = ATOMIC_INIT(AP_DEFAULT_MAX_MSG_SIZE);
+EXPORT_SYMBOL(ap_max_msg_size);
+
+static struct device *ap_root_device;
+
+/* Hashtable of all queue devices on the AP bus */
+DEFINE_HASHTABLE(ap_queues, 8);
+/* lock used for the ap_queues hashtable */
+DEFINE_SPINLOCK(ap_queues_lock);
+
+/* Default permissions (ioctl, card and domain masking) */
+struct ap_perms ap_perms;
+EXPORT_SYMBOL(ap_perms);
+DEFINE_MUTEX(ap_perms_mutex);
+EXPORT_SYMBOL(ap_perms_mutex);
+
+/* # of bus scans since init */
+static atomic64_t ap_scan_bus_count;
+
+/* # of bindings complete since init */
+static atomic64_t ap_bindings_complete_count = ATOMIC64_INIT(0);
+
+/* completion for initial APQN bindings complete */
+static DECLARE_COMPLETION(ap_init_apqn_bindings_complete);
+
+static struct ap_config_info *ap_qci_info;
+static struct ap_config_info *ap_qci_info_old;
+
+/*
+ * AP bus related debug feature things.
+ */
+debug_info_t *ap_dbf_info;
+
+/*
+ * Workqueue timer for bus rescan.
+ */
+static struct timer_list ap_config_timer;
+static int ap_config_time = AP_CONFIG_TIME;
+static void ap_scan_bus(struct work_struct *);
+static DECLARE_WORK(ap_scan_work, ap_scan_bus);
+
+/*
+ * Tasklet & timer for AP request polling and interrupts
+ */
+static void ap_tasklet_fn(unsigned long);
+static DECLARE_TASKLET_OLD(ap_tasklet, ap_tasklet_fn);
+static DECLARE_WAIT_QUEUE_HEAD(ap_poll_wait);
+static struct task_struct *ap_poll_kthread;
+static DEFINE_MUTEX(ap_poll_thread_mutex);
+static DEFINE_SPINLOCK(ap_poll_timer_lock);
+static struct hrtimer ap_poll_timer;
+/*
+ * In LPAR poll with 4kHz frequency. Poll every 250000 nanoseconds.
+ * If z/VM change to 1500000 nanoseconds to adjust to z/VM polling.
+ */
+static unsigned long long poll_timeout = 250000;
+
+/* 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;
+
+/* Adapter interrupt definitions */
+static void ap_interrupt_handler(struct airq_struct *airq,
+				 struct tpi_info *tpi_info);
+
+static bool ap_irq_flag;
+
+static struct airq_struct ap_airq = {
+	.handler = ap_interrupt_handler,
+	.isc = AP_ISC,
+};
+
+/**
+ * ap_airq_ptr() - Get the address of the adapter interrupt indicator
+ *
+ * Returns the address of the local-summary-indicator of the adapter
+ * interrupt handler for AP, or NULL if adapter interrupts are not
+ * available.
+ */
+void *ap_airq_ptr(void)
+{
+	if (ap_irq_flag)
+		return ap_airq.lsi_ptr;
+	return NULL;
+}
+
+/**
+ * ap_interrupts_available(): Test if AP interrupts are available.
+ *
+ * Returns 1 if AP interrupts are available.
+ */
+static int ap_interrupts_available(void)
+{
+	return test_facility(65);
+}
+
+/**
+ * ap_qci_available(): Test if AP configuration
+ * information can be queried via QCI subfunction.
+ *
+ * Returns 1 if subfunction PQAP(QCI) is available.
+ */
+static int ap_qci_available(void)
+{
+	return test_facility(12);
+}
+
+/**
+ * ap_apft_available(): Test if AP facilities test (APFT)
+ * facility is available.
+ *
+ * Returns 1 if APFT is available.
+ */
+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_qci_info)
+		return ap_qci_info->qact;
+	return 0;
+}
+
+/*
+ * 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_fetch_qci_info(struct ap_config_info *info)
+{
+	if (!ap_qci_available())
+		return -EOPNOTSUPP;
+	if (!info)
+		return -EINVAL;
+	return ap_qci(info);
+}
+
+/**
+ * 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 __init ap_init_qci_info(void)
+{
+	if (!ap_qci_available()) {
+		AP_DBF_INFO("%s QCI not supported\n", __func__);
+		return;
+	}
+
+	ap_qci_info = kzalloc(sizeof(*ap_qci_info), GFP_KERNEL);
+	if (!ap_qci_info)
+		return;
+	ap_qci_info_old = kzalloc(sizeof(*ap_qci_info_old), GFP_KERNEL);
+	if (!ap_qci_info_old) {
+		kfree(ap_qci_info);
+		ap_qci_info = NULL;
+		return;
+	}
+	if (ap_fetch_qci_info(ap_qci_info) != 0) {
+		kfree(ap_qci_info);
+		kfree(ap_qci_info_old);
+		ap_qci_info = NULL;
+		ap_qci_info_old = NULL;
+		return;
+	}
+	AP_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_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_INFO("%s new ap_max_domain_id is %d\n",
+				    __func__, ap_max_domain_id);
+		}
+	}
+
+	memcpy(ap_qci_info_old, ap_qci_info, sizeof(*ap_qci_info));
+}
+
+/*
+ * ap_test_config(): helper function to extract the nrth bit
+ *		     within the unsigned int array field.
+ */
+static inline int ap_test_config(unsigned int *field, unsigned int nr)
+{
+	return ap_test_bit((field + (nr >> 5)), (nr & 0x1f));
+}
+
+/*
+ * ap_test_config_card_id(): Test, whether an AP card ID is configured.
+ *
+ * Returns 0 if the card is not configured
+ *	   1 if the card is configured or
+ *	     if the configuration information is not available
+ */
+static inline int ap_test_config_card_id(unsigned int 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.
+ *
+ * Returns 0 if the usage domain is not configured
+ *	   1 if the usage domain is configured or
+ *	     if the configuration information is not available
+ */
+int ap_test_config_usage_domain(unsigned int 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);
+
+/*
+ * ap_test_config_ctrl_domain(): Test, whether an AP control domain
+ * is configured.
+ * @domain AP control domain ID
+ *
+ * Returns 1 if the control domain is configured
+ *	   0 in all other cases
+ */
+int ap_test_config_ctrl_domain(unsigned int domain)
+{
+	if (!ap_qci_info || domain > ap_max_domain_id)
+		return 0;
+	return ap_test_config(ap_qci_info->adm, domain);
+}
+EXPORT_SYMBOL(ap_test_config_ctrl_domain);
+
+/*
+ * ap_queue_info(): Check and get AP queue info.
+ * Returns true if TAPQ succeeded and the info is filled or
+ * false otherwise.
+ */
+static bool ap_queue_info(ap_qid_t qid, int *q_type, unsigned int *q_fac,
+			  int *q_depth, int *q_ml, bool *q_decfg, bool *q_cstop)
+{
+	struct ap_queue_status status;
+	union {
+		unsigned long value;
+		struct {
+			unsigned int fac   : 32; /* facility bits */
+			unsigned int at	   :  8; /* ap type */
+			unsigned int _res1 :  8;
+			unsigned int _res2 :  4;
+			unsigned int ml	   :  4; /* apxl ml */
+			unsigned int _res3 :  4;
+			unsigned int qd	   :  4; /* queue depth */
+		} tapq_gr2;
+	} tapq_info;
+
+	tapq_info.value = 0;
+
+	/* 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(), &tapq_info.value);
+	switch (status.response_code) {
+	case AP_RESPONSE_NORMAL:
+	case AP_RESPONSE_RESET_IN_PROGRESS:
+	case AP_RESPONSE_DECONFIGURED:
+	case AP_RESPONSE_CHECKSTOPPED:
+	case AP_RESPONSE_BUSY:
+		/*
+		 * 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(!tapq_info.value))
+			return false;
+		*q_type = tapq_info.tapq_gr2.at;
+		*q_fac = tapq_info.tapq_gr2.fac;
+		*q_depth = tapq_info.tapq_gr2.qd;
+		*q_ml = tapq_info.tapq_gr2.ml;
+		*q_decfg = status.response_code == AP_RESPONSE_DECONFIGURED;
+		*q_cstop = status.response_code == AP_RESPONSE_CHECKSTOPPED;
+		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
+			 * modify the function bits based on the type.
+			 */
+		case AP_DEVICE_TYPE_CEX2A:
+		case AP_DEVICE_TYPE_CEX3A:
+			*q_fac |= 0x08000000;
+			break;
+		case AP_DEVICE_TYPE_CEX2C:
+		case AP_DEVICE_TYPE_CEX3C:
+			*q_fac |= 0x10000000;
+			break;
+		default:
+			break;
+		}
+		return true;
+	default:
+		/*
+		 * A response code which indicates, there is no info available.
+		 */
+		return false;
+	}
+}
+
+void ap_wait(enum ap_sm_wait wait)
+{
+	ktime_t hr_time;
+
+	switch (wait) {
+	case AP_SM_WAIT_AGAIN:
+	case AP_SM_WAIT_INTERRUPT:
+		if (ap_irq_flag)
+			break;
+		if (ap_poll_kthread) {
+			wake_up(&ap_poll_wait);
+			break;
+		}
+		fallthrough;
+	case AP_SM_WAIT_TIMEOUT:
+		spin_lock_bh(&ap_poll_timer_lock);
+		if (!hrtimer_is_queued(&ap_poll_timer)) {
+			hr_time = poll_timeout;
+			hrtimer_forward_now(&ap_poll_timer, hr_time);
+			hrtimer_restart(&ap_poll_timer);
+		}
+		spin_unlock_bh(&ap_poll_timer_lock);
+		break;
+	case AP_SM_WAIT_NONE:
+	default:
+		break;
+	}
+}
+
+/**
+ * ap_request_timeout(): Handling of request timeouts
+ * @t: timer making this callback
+ *
+ * Handles request timeouts.
+ */
+void ap_request_timeout(struct timer_list *t)
+{
+	struct ap_queue *aq = from_timer(aq, t, timeout);
+
+	spin_lock_bh(&aq->lock);
+	ap_wait(ap_sm_event(aq, AP_SM_EVENT_TIMEOUT));
+	spin_unlock_bh(&aq->lock);
+}
+
+/**
+ * ap_poll_timeout(): AP receive polling for finished AP requests.
+ * @unused: Unused pointer.
+ *
+ * Schedules the AP tasklet using a high resolution timer.
+ */
+static enum hrtimer_restart ap_poll_timeout(struct hrtimer *unused)
+{
+	tasklet_schedule(&ap_tasklet);
+	return HRTIMER_NORESTART;
+}
+
+/**
+ * ap_interrupt_handler() - Schedule ap_tasklet on interrupt
+ * @airq: pointer to adapter interrupt descriptor
+ * @tpi_info: ignored
+ */
+static void ap_interrupt_handler(struct airq_struct *airq,
+				 struct tpi_info *tpi_info)
+{
+	inc_irq_stat(IRQIO_APB);
+	tasklet_schedule(&ap_tasklet);
+}
+
+/**
+ * ap_tasklet_fn(): Tasklet to poll all AP devices.
+ * @dummy: Unused variable
+ *
+ * Poll all AP devices on the bus.
+ */
+static void ap_tasklet_fn(unsigned long dummy)
+{
+	int bkt;
+	struct ap_queue *aq;
+	enum ap_sm_wait wait = AP_SM_WAIT_NONE;
+
+	/* Reset the indicator if interrupts are used. Thus new interrupts can
+	 * be received. Doing it in the beginning of the tasklet is therefor
+	 * important that no requests on any AP get lost.
+	 */
+	if (ap_irq_flag)
+		xchg(ap_airq.lsi_ptr, 0);
+
+	spin_lock_bh(&ap_queues_lock);
+	hash_for_each(ap_queues, bkt, aq, hnode) {
+		spin_lock_bh(&aq->lock);
+		wait = min(wait, ap_sm_event_loop(aq, AP_SM_EVENT_POLL));
+		spin_unlock_bh(&aq->lock);
+	}
+	spin_unlock_bh(&ap_queues_lock);
+
+	ap_wait(wait);
+}
+
+static int ap_pending_requests(void)
+{
+	int bkt;
+	struct ap_queue *aq;
+
+	spin_lock_bh(&ap_queues_lock);
+	hash_for_each(ap_queues, bkt, aq, hnode) {
+		if (aq->queue_count == 0)
+			continue;
+		spin_unlock_bh(&ap_queues_lock);
+		return 1;
+	}
+	spin_unlock_bh(&ap_queues_lock);
+	return 0;
+}
+
+/**
+ * ap_poll_thread(): Thread that polls for finished requests.
+ * @data: Unused pointer
+ *
+ * AP bus poll thread. The purpose of this thread is to poll for
+ * finished requests in a loop if there is a "free" cpu - that is
+ * a cpu that doesn't have anything better to do. The polling stops
+ * as soon as there is another task or if all messages have been
+ * delivered.
+ */
+static int ap_poll_thread(void *data)
+{
+	DECLARE_WAITQUEUE(wait, current);
+
+	set_user_nice(current, MAX_NICE);
+	set_freezable();
+	while (!kthread_should_stop()) {
+		add_wait_queue(&ap_poll_wait, &wait);
+		set_current_state(TASK_INTERRUPTIBLE);
+		if (!ap_pending_requests()) {
+			schedule();
+			try_to_freeze();
+		}
+		set_current_state(TASK_RUNNING);
+		remove_wait_queue(&ap_poll_wait, &wait);
+		if (need_resched()) {
+			schedule();
+			try_to_freeze();
+			continue;
+		}
+		ap_tasklet_fn(0);
+	}
+
+	return 0;
+}
+
+static int ap_poll_thread_start(void)
+{
+	int rc;
+
+	if (ap_irq_flag || ap_poll_kthread)
+		return 0;
+	mutex_lock(&ap_poll_thread_mutex);
+	ap_poll_kthread = kthread_run(ap_poll_thread, NULL, "appoll");
+	rc = PTR_ERR_OR_ZERO(ap_poll_kthread);
+	if (rc)
+		ap_poll_kthread = NULL;
+	mutex_unlock(&ap_poll_thread_mutex);
+	return rc;
+}
+
+static void ap_poll_thread_stop(void)
+{
+	if (!ap_poll_kthread)
+		return;
+	mutex_lock(&ap_poll_thread_mutex);
+	kthread_stop(ap_poll_kthread);
+	ap_poll_kthread = NULL;
+	mutex_unlock(&ap_poll_thread_mutex);
+}
+
+#define is_card_dev(x) ((x)->parent == ap_root_device)
+#define is_queue_dev(x) ((x)->parent != ap_root_device)
+
+/**
+ * ap_bus_match()
+ * @dev: Pointer to device
+ * @drv: Pointer to device_driver
+ *
+ * AP bus driver registration/unregistration.
+ */
+static int ap_bus_match(struct device *dev, struct device_driver *drv)
+{
+	struct ap_driver *ap_drv = to_ap_drv(drv);
+	struct ap_device_id *id;
+
+	/*
+	 * Compare device type of the device with the list of
+	 * supported types of the device_driver.
+	 */
+	for (id = ap_drv->ids; id->match_flags; id++) {
+		if (is_card_dev(dev) &&
+		    id->match_flags & AP_DEVICE_ID_MATCH_CARD_TYPE &&
+		    id->dev_type == to_ap_dev(dev)->device_type)
+			return 1;
+		if (is_queue_dev(dev) &&
+		    id->match_flags & AP_DEVICE_ID_MATCH_QUEUE_TYPE &&
+		    id->dev_type == to_ap_dev(dev)->device_type)
+			return 1;
+	}
+	return 0;
+}
+
+/**
+ * ap_uevent(): Uevent function for AP devices.
+ * @dev: Pointer to device
+ * @env: Pointer to kobj_uevent_env
+ *
+ * It sets up a single environment variable DEV_TYPE which contains the
+ * hardware device type.
+ */
+static int ap_uevent(struct device *dev, struct kobj_uevent_env *env)
+{
+	int rc = 0;
+	struct ap_device *ap_dev = to_ap_dev(dev);
+
+	/* Uevents from ap bus core don't need extensions to the env */
+	if (dev == ap_root_device)
+		return 0;
+
+	if (is_card_dev(dev)) {
+		struct ap_card *ac = to_ap_card(&ap_dev->device);
+
+		/* Set up DEV_TYPE environment variable. */
+		rc = add_uevent_var(env, "DEV_TYPE=%04X", ap_dev->device_type);
+		if (rc)
+			return rc;
+		/* Add MODALIAS= */
+		rc = add_uevent_var(env, "MODALIAS=ap:t%02X", ap_dev->device_type);
+		if (rc)
+			return rc;
+
+		/* Add MODE=<accel|cca|ep11> */
+		if (ap_test_bit(&ac->functions, AP_FUNC_ACCEL))
+			rc = add_uevent_var(env, "MODE=accel");
+		else if (ap_test_bit(&ac->functions, AP_FUNC_COPRO))
+			rc = add_uevent_var(env, "MODE=cca");
+		else if (ap_test_bit(&ac->functions, AP_FUNC_EP11))
+			rc = add_uevent_var(env, "MODE=ep11");
+		if (rc)
+			return rc;
+	} else {
+		struct ap_queue *aq = to_ap_queue(&ap_dev->device);
+
+		/* Add MODE=<accel|cca|ep11> */
+		if (ap_test_bit(&aq->card->functions, AP_FUNC_ACCEL))
+			rc = add_uevent_var(env, "MODE=accel");
+		else if (ap_test_bit(&aq->card->functions, AP_FUNC_COPRO))
+			rc = add_uevent_var(env, "MODE=cca");
+		else if (ap_test_bit(&aq->card->functions, AP_FUNC_EP11))
+			rc = add_uevent_var(env, "MODE=ep11");
+		if (rc)
+			return rc;
+	}
+
+	return 0;
+}
+
+static void ap_send_init_scan_done_uevent(void)
+{
+	char *envp[] = { "INITSCAN=done", NULL };
+
+	kobject_uevent_env(&ap_root_device->kobj, KOBJ_CHANGE, envp);
+}
+
+static void ap_send_bindings_complete_uevent(void)
+{
+	char buf[32];
+	char *envp[] = { "BINDINGS=complete", buf, NULL };
+
+	snprintf(buf, sizeof(buf), "COMPLETECOUNT=%llu",
+		 atomic64_inc_return(&ap_bindings_complete_count));
+	kobject_uevent_env(&ap_root_device->kobj, KOBJ_CHANGE, envp);
+}
+
+void ap_send_config_uevent(struct ap_device *ap_dev, bool cfg)
+{
+	char buf[16];
+	char *envp[] = { buf, NULL };
+
+	snprintf(buf, sizeof(buf), "CONFIG=%d", cfg ? 1 : 0);
+
+	kobject_uevent_env(&ap_dev->device.kobj, KOBJ_CHANGE, envp);
+}
+EXPORT_SYMBOL(ap_send_config_uevent);
+
+void ap_send_online_uevent(struct ap_device *ap_dev, int online)
+{
+	char buf[16];
+	char *envp[] = { buf, NULL };
+
+	snprintf(buf, sizeof(buf), "ONLINE=%d", online ? 1 : 0);
+
+	kobject_uevent_env(&ap_dev->device.kobj, KOBJ_CHANGE, envp);
+}
+EXPORT_SYMBOL(ap_send_online_uevent);
+
+static void ap_send_mask_changed_uevent(unsigned long *newapm,
+					unsigned long *newaqm)
+{
+	char buf[100];
+	char *envp[] = { buf, NULL };
+
+	if (newapm)
+		snprintf(buf, sizeof(buf),
+			 "APMASK=0x%016lx%016lx%016lx%016lx\n",
+			 newapm[0], newapm[1], newapm[2], newapm[3]);
+	else
+		snprintf(buf, sizeof(buf),
+			 "AQMASK=0x%016lx%016lx%016lx%016lx\n",
+			 newaqm[0], newaqm[1], newaqm[2], newaqm[3]);
+
+	kobject_uevent_env(&ap_root_device->kobj, KOBJ_CHANGE, envp);
+}
+
+/*
+ * calc # of bound APQNs
+ */
+
+struct __ap_calc_ctrs {
+	unsigned int apqns;
+	unsigned int bound;
+};
+
+static int __ap_calc_helper(struct device *dev, void *arg)
+{
+	struct __ap_calc_ctrs *pctrs = (struct __ap_calc_ctrs *)arg;
+
+	if (is_queue_dev(dev)) {
+		pctrs->apqns++;
+		if (dev->driver)
+			pctrs->bound++;
+	}
+
+	return 0;
+}
+
+static void ap_calc_bound_apqns(unsigned int *apqns, unsigned int *bound)
+{
+	struct __ap_calc_ctrs ctrs;
+
+	memset(&ctrs, 0, sizeof(ctrs));
+	bus_for_each_dev(&ap_bus_type, NULL, (void *)&ctrs, __ap_calc_helper);
+
+	*apqns = ctrs.apqns;
+	*bound = ctrs.bound;
+}
+
+/*
+ * After initial ap bus scan do check if all existing APQNs are
+ * bound to device drivers.
+ */
+static void ap_check_bindings_complete(void)
+{
+	unsigned int apqns, bound;
+
+	if (atomic64_read(&ap_scan_bus_count) >= 1) {
+		ap_calc_bound_apqns(&apqns, &bound);
+		if (bound == apqns) {
+			if (!completion_done(&ap_init_apqn_bindings_complete)) {
+				complete_all(&ap_init_apqn_bindings_complete);
+				AP_DBF_INFO("%s complete\n", __func__);
+			}
+			ap_send_bindings_complete_uevent();
+		}
+	}
+}
+
+/*
+ * Interface to wait for the AP bus to have done one initial ap bus
+ * scan and all detected APQNs have been bound to device drivers.
+ * If these both conditions are not fulfilled, this function blocks
+ * on a condition with wait_for_completion_interruptible_timeout().
+ * If these both conditions are fulfilled (before the timeout hits)
+ * the return value is 0. If the timeout (in jiffies) hits instead
+ * -ETIME is returned. On failures negative return values are
+ * returned to the caller.
+ */
+int ap_wait_init_apqn_bindings_complete(unsigned long timeout)
+{
+	long l;
+
+	if (completion_done(&ap_init_apqn_bindings_complete))
+		return 0;
+
+	if (timeout)
+		l = wait_for_completion_interruptible_timeout(
+			&ap_init_apqn_bindings_complete, timeout);
+	else
+		l = wait_for_completion_interruptible(
+			&ap_init_apqn_bindings_complete);
+	if (l < 0)
+		return l == -ERESTARTSYS ? -EINTR : l;
+	else if (l == 0 && timeout)
+		return -ETIME;
+
+	return 0;
+}
+EXPORT_SYMBOL(ap_wait_init_apqn_bindings_complete);
+
+static int __ap_queue_devices_with_id_unregister(struct device *dev, void *data)
+{
+	if (is_queue_dev(dev) &&
+	    AP_QID_CARD(to_ap_queue(dev)->qid) == (int)(long)data)
+		device_unregister(dev);
+	return 0;
+}
+
+static int __ap_revise_reserved(struct device *dev, void *dummy)
+{
+	int rc, card, queue, devres, drvres;
+
+	if (is_queue_dev(dev)) {
+		card = AP_QID_CARD(to_ap_queue(dev)->qid);
+		queue = AP_QID_QUEUE(to_ap_queue(dev)->qid);
+		mutex_lock(&ap_perms_mutex);
+		devres = test_bit_inv(card, ap_perms.apm) &&
+			test_bit_inv(queue, ap_perms.aqm);
+		mutex_unlock(&ap_perms_mutex);
+		drvres = to_ap_drv(dev->driver)->flags
+			& AP_DRIVER_FLAG_DEFAULT;
+		if (!!devres != !!drvres) {
+			AP_DBF_DBG("%s reprobing queue=%02x.%04x\n",
+				   __func__, card, queue);
+			rc = device_reprobe(dev);
+			if (rc)
+				AP_DBF_WARN("%s reprobing queue=%02x.%04x failed\n",
+					    __func__, card, queue);
+		}
+	}
+
+	return 0;
+}
+
+static void ap_bus_revise_bindings(void)
+{
+	bus_for_each_dev(&ap_bus_type, NULL, NULL, __ap_revise_reserved);
+}
+
+/**
+ * ap_owned_by_def_drv: indicates whether an AP adapter is reserved for the
+ *			default host driver or not.
+ * @card: the APID of the adapter card to check
+ * @queue: the APQI of the queue to check
+ *
+ * Note: the ap_perms_mutex must be locked by the caller of this function.
+ *
+ * Return: an int specifying whether the AP adapter is reserved for the host (1)
+ *	   or not (0).
+ */
+int ap_owned_by_def_drv(int card, int queue)
+{
+	int rc = 0;
+
+	if (card < 0 || card >= AP_DEVICES || queue < 0 || queue >= AP_DOMAINS)
+		return -EINVAL;
+
+	if (test_bit_inv(card, ap_perms.apm) &&
+	    test_bit_inv(queue, ap_perms.aqm))
+		rc = 1;
+
+	return rc;
+}
+EXPORT_SYMBOL(ap_owned_by_def_drv);
+
+/**
+ * ap_apqn_in_matrix_owned_by_def_drv: indicates whether every APQN contained in
+ *				       a set is reserved for the host drivers
+ *				       or not.
+ * @apm: a bitmap specifying a set of APIDs comprising the APQNs to check
+ * @aqm: a bitmap specifying a set of APQIs comprising the APQNs to check
+ *
+ * Note: the ap_perms_mutex must be locked by the caller of this function.
+ *
+ * Return: an int specifying whether each APQN is reserved for the host (1) or
+ *	   not (0)
+ */
+int ap_apqn_in_matrix_owned_by_def_drv(unsigned long *apm,
+				       unsigned long *aqm)
+{
+	int card, queue, rc = 0;
+
+	for (card = 0; !rc && card < AP_DEVICES; card++)
+		if (test_bit_inv(card, apm) &&
+		    test_bit_inv(card, ap_perms.apm))
+			for (queue = 0; !rc && queue < AP_DOMAINS; queue++)
+				if (test_bit_inv(queue, aqm) &&
+				    test_bit_inv(queue, ap_perms.aqm))
+					rc = 1;
+
+	return rc;
+}
+EXPORT_SYMBOL(ap_apqn_in_matrix_owned_by_def_drv);
+
+static int ap_device_probe(struct device *dev)
+{
+	struct ap_device *ap_dev = to_ap_dev(dev);
+	struct ap_driver *ap_drv = to_ap_drv(dev->driver);
+	int card, queue, devres, drvres, rc = -ENODEV;
+
+	if (!get_device(dev))
+		return rc;
+
+	if (is_queue_dev(dev)) {
+		/*
+		 * If the apqn is marked as reserved/used by ap bus and
+		 * default drivers, only probe with drivers with the default
+		 * flag set. If it is not marked, only probe with drivers
+		 * with the default flag not set.
+		 */
+		card = AP_QID_CARD(to_ap_queue(dev)->qid);
+		queue = AP_QID_QUEUE(to_ap_queue(dev)->qid);
+		mutex_lock(&ap_perms_mutex);
+		devres = test_bit_inv(card, ap_perms.apm) &&
+			test_bit_inv(queue, ap_perms.aqm);
+		mutex_unlock(&ap_perms_mutex);
+		drvres = ap_drv->flags & AP_DRIVER_FLAG_DEFAULT;
+		if (!!devres != !!drvres)
+			goto out;
+	}
+
+	/* Add queue/card to list of active queues/cards */
+	spin_lock_bh(&ap_queues_lock);
+	if (is_queue_dev(dev))
+		hash_add(ap_queues, &to_ap_queue(dev)->hnode,
+			 to_ap_queue(dev)->qid);
+	spin_unlock_bh(&ap_queues_lock);
+
+	rc = ap_drv->probe ? ap_drv->probe(ap_dev) : -ENODEV;
+
+	if (rc) {
+		spin_lock_bh(&ap_queues_lock);
+		if (is_queue_dev(dev))
+			hash_del(&to_ap_queue(dev)->hnode);
+		spin_unlock_bh(&ap_queues_lock);
+	} else {
+		ap_check_bindings_complete();
+	}
+
+out:
+	if (rc)
+		put_device(dev);
+	return rc;
+}
+
+static void ap_device_remove(struct device *dev)
+{
+	struct ap_device *ap_dev = to_ap_dev(dev);
+	struct ap_driver *ap_drv = to_ap_drv(dev->driver);
+
+	/* prepare ap queue device removal */
+	if (is_queue_dev(dev))
+		ap_queue_prepare_remove(to_ap_queue(dev));
+
+	/* driver's chance to clean up gracefully */
+	if (ap_drv->remove)
+		ap_drv->remove(ap_dev);
+
+	/* now do the ap queue device remove */
+	if (is_queue_dev(dev))
+		ap_queue_remove(to_ap_queue(dev));
+
+	/* Remove queue/card from list of active queues/cards */
+	spin_lock_bh(&ap_queues_lock);
+	if (is_queue_dev(dev))
+		hash_del(&to_ap_queue(dev)->hnode);
+	spin_unlock_bh(&ap_queues_lock);
+
+	put_device(dev);
+}
+
+struct ap_queue *ap_get_qdev(ap_qid_t qid)
+{
+	int bkt;
+	struct ap_queue *aq;
+
+	spin_lock_bh(&ap_queues_lock);
+	hash_for_each(ap_queues, bkt, aq, hnode) {
+		if (aq->qid == qid) {
+			get_device(&aq->ap_dev.device);
+			spin_unlock_bh(&ap_queues_lock);
+			return aq;
+		}
+	}
+	spin_unlock_bh(&ap_queues_lock);
+
+	return NULL;
+}
+EXPORT_SYMBOL(ap_get_qdev);
+
+int ap_driver_register(struct ap_driver *ap_drv, struct module *owner,
+		       char *name)
+{
+	struct device_driver *drv = &ap_drv->driver;
+
+	drv->bus = &ap_bus_type;
+	drv->owner = owner;
+	drv->name = name;
+	return driver_register(drv);
+}
+EXPORT_SYMBOL(ap_driver_register);
+
+void ap_driver_unregister(struct ap_driver *ap_drv)
+{
+	driver_unregister(&ap_drv->driver);
+}
+EXPORT_SYMBOL(ap_driver_unregister);
+
+void ap_bus_force_rescan(void)
+{
+	/* Only trigger AP bus scans after the initial scan is done */
+	if (atomic64_read(&ap_scan_bus_count) <= 0)
+		return;
+
+	/* processing a asynchronous bus rescan */
+	del_timer(&ap_config_timer);
+	queue_work(system_long_wq, &ap_scan_work);
+	flush_work(&ap_scan_work);
+}
+EXPORT_SYMBOL(ap_bus_force_rescan);
+
+/*
+ * A config change has happened, force an ap bus rescan.
+ */
+void ap_bus_cfg_chg(void)
+{
+	AP_DBF_DBG("%s config change, forcing bus rescan\n", __func__);
+
+	ap_bus_force_rescan();
+}
+
+/*
+ * hex2bitmap() - parse hex mask string and set bitmap.
+ * Valid strings are "0x012345678" with at least one valid hex number.
+ * Rest of the bitmap to the right is padded with 0. No spaces allowed
+ * within the string, the leading 0x may be omitted.
+ * Returns the bitmask with exactly the bits set as given by the hex
+ * string (both in big endian order).
+ */
+static int hex2bitmap(const char *str, unsigned long *bitmap, int bits)
+{
+	int i, n, b;
+
+	/* bits needs to be a multiple of 8 */
+	if (bits & 0x07)
+		return -EINVAL;
+
+	if (str[0] == '0' && str[1] == 'x')
+		str++;
+	if (*str == 'x')
+		str++;
+
+	for (i = 0; isxdigit(*str) && i < bits; str++) {
+		b = hex_to_bin(*str);
+		for (n = 0; n < 4; n++)
+			if (b & (0x08 >> n))
+				set_bit_inv(i + n, bitmap);
+		i += 4;
+	}
+
+	if (*str == '\n')
+		str++;
+	if (*str)
+		return -EINVAL;
+	return 0;
+}
+
+/*
+ * modify_bitmap() - parse bitmask argument and modify an existing
+ * bit mask accordingly. A concatenation (done with ',') of these
+ * terms is recognized:
+ *   +<bitnr>[-<bitnr>] or -<bitnr>[-<bitnr>]
+ * <bitnr> may be any valid number (hex, decimal or octal) in the range
+ * 0...bits-1; the leading + or - is required. Here are some examples:
+ *   +0-15,+32,-128,-0xFF
+ *   -0-255,+1-16,+0x128
+ *   +1,+2,+3,+4,-5,-7-10
+ * Returns the new bitmap after all changes have been applied. Every
+ * positive value in the string will set a bit and every negative value
+ * in the string will clear a bit. As a bit may be touched more than once,
+ * the last 'operation' wins:
+ * +0-255,-128 = first bits 0-255 will be set, then bit 128 will be
+ * cleared again. All other bits are unmodified.
+ */
+static int modify_bitmap(const char *str, unsigned long *bitmap, int bits)
+{
+	int a, i, z;
+	char *np, sign;
+
+	/* bits needs to be a multiple of 8 */
+	if (bits & 0x07)
+		return -EINVAL;
+
+	while (*str) {
+		sign = *str++;
+		if (sign != '+' && sign != '-')
+			return -EINVAL;
+		a = z = simple_strtoul(str, &np, 0);
+		if (str == np || a >= bits)
+			return -EINVAL;
+		str = np;
+		if (*str == '-') {
+			z = simple_strtoul(++str, &np, 0);
+			if (str == np || a > z || z >= bits)
+				return -EINVAL;
+			str = np;
+		}
+		for (i = a; i <= z; i++)
+			if (sign == '+')
+				set_bit_inv(i, bitmap);
+			else
+				clear_bit_inv(i, bitmap);
+		while (*str == ',' || *str == '\n')
+			str++;
+	}
+
+	return 0;
+}
+
+static int ap_parse_bitmap_str(const char *str, unsigned long *bitmap, int bits,
+			       unsigned long *newmap)
+{
+	unsigned long size;
+	int rc;
+
+	size = BITS_TO_LONGS(bits) * sizeof(unsigned long);
+	if (*str == '+' || *str == '-') {
+		memcpy(newmap, bitmap, size);
+		rc = modify_bitmap(str, newmap, bits);
+	} else {
+		memset(newmap, 0, size);
+		rc = hex2bitmap(str, newmap, bits);
+	}
+	return rc;
+}
+
+int ap_parse_mask_str(const char *str,
+		      unsigned long *bitmap, int bits,
+		      struct mutex *lock)
+{
+	unsigned long *newmap, size;
+	int rc;
+
+	/* bits needs to be a multiple of 8 */
+	if (bits & 0x07)
+		return -EINVAL;
+
+	size = BITS_TO_LONGS(bits) * sizeof(unsigned long);
+	newmap = kmalloc(size, GFP_KERNEL);
+	if (!newmap)
+		return -ENOMEM;
+	if (mutex_lock_interruptible(lock)) {
+		kfree(newmap);
+		return -ERESTARTSYS;
+	}
+	rc = ap_parse_bitmap_str(str, bitmap, bits, newmap);
+	if (rc == 0)
+		memcpy(bitmap, newmap, size);
+	mutex_unlock(lock);
+	kfree(newmap);
+	return rc;
+}
+EXPORT_SYMBOL(ap_parse_mask_str);
+
+/*
+ * AP bus attributes.
+ */
+
+static ssize_t ap_domain_show(struct bus_type *bus, char *buf)
+{
+	return scnprintf(buf, PAGE_SIZE, "%d\n", ap_domain_index);
+}
+
+static ssize_t ap_domain_store(struct bus_type *bus,
+			       const char *buf, size_t count)
+{
+	int domain;
+
+	if (sscanf(buf, "%i\n", &domain) != 1 ||
+	    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_INFO("%s stored new default domain=%d\n",
+		    __func__, domain);
+
+	return count;
+}
+
+static BUS_ATTR_RW(ap_domain);
+
+static ssize_t ap_control_domain_mask_show(struct bus_type *bus, char *buf)
+{
+	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_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_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_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_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_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);
+
+static ssize_t ap_interrupts_show(struct bus_type *bus, char *buf)
+{
+	return scnprintf(buf, PAGE_SIZE, "%d\n",
+			 ap_irq_flag ? 1 : 0);
+}
+
+static BUS_ATTR_RO(ap_interrupts);
+
+static ssize_t config_time_show(struct bus_type *bus, char *buf)
+{
+	return scnprintf(buf, PAGE_SIZE, "%d\n", ap_config_time);
+}
+
+static ssize_t config_time_store(struct bus_type *bus,
+				 const char *buf, size_t count)
+{
+	int time;
+
+	if (sscanf(buf, "%d\n", &time) != 1 || time < 5 || time > 120)
+		return -EINVAL;
+	ap_config_time = time;
+	mod_timer(&ap_config_timer, jiffies + ap_config_time * HZ);
+	return count;
+}
+
+static BUS_ATTR_RW(config_time);
+
+static ssize_t poll_thread_show(struct bus_type *bus, char *buf)
+{
+	return scnprintf(buf, PAGE_SIZE, "%d\n", ap_poll_kthread ? 1 : 0);
+}
+
+static ssize_t poll_thread_store(struct bus_type *bus,
+				 const char *buf, size_t count)
+{
+	int flag, rc;
+
+	if (sscanf(buf, "%d\n", &flag) != 1)
+		return -EINVAL;
+	if (flag) {
+		rc = ap_poll_thread_start();
+		if (rc)
+			count = rc;
+	} else {
+		ap_poll_thread_stop();
+	}
+	return count;
+}
+
+static BUS_ATTR_RW(poll_thread);
+
+static ssize_t poll_timeout_show(struct bus_type *bus, char *buf)
+{
+	return scnprintf(buf, PAGE_SIZE, "%llu\n", poll_timeout);
+}
+
+static ssize_t poll_timeout_store(struct bus_type *bus, const char *buf,
+				  size_t count)
+{
+	unsigned long long time;
+	ktime_t hr_time;
+
+	/* 120 seconds = maximum poll interval */
+	if (sscanf(buf, "%llu\n", &time) != 1 || time < 1 ||
+	    time > 120000000000ULL)
+		return -EINVAL;
+	poll_timeout = time;
+	hr_time = poll_timeout;
+
+	spin_lock_bh(&ap_poll_timer_lock);
+	hrtimer_cancel(&ap_poll_timer);
+	hrtimer_set_expires(&ap_poll_timer, hr_time);
+	hrtimer_start_expires(&ap_poll_timer, HRTIMER_MODE_ABS);
+	spin_unlock_bh(&ap_poll_timer_lock);
+
+	return count;
+}
+
+static BUS_ATTR_RW(poll_timeout);
+
+static ssize_t ap_max_domain_id_show(struct bus_type *bus, char *buf)
+{
+	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;
+
+	if (mutex_lock_interruptible(&ap_perms_mutex))
+		return -ERESTARTSYS;
+	rc = scnprintf(buf, PAGE_SIZE,
+		       "0x%016lx%016lx%016lx%016lx\n",
+		       ap_perms.apm[0], ap_perms.apm[1],
+		       ap_perms.apm[2], ap_perms.apm[3]);
+	mutex_unlock(&ap_perms_mutex);
+
+	return rc;
+}
+
+static int __verify_card_reservations(struct device_driver *drv, void *data)
+{
+	int rc = 0;
+	struct ap_driver *ap_drv = to_ap_drv(drv);
+	unsigned long *newapm = (unsigned long *)data;
+
+	/*
+	 * increase the driver's module refcounter to be sure it is not
+	 * going away when we invoke the callback function.
+	 */
+	if (!try_module_get(drv->owner))
+		return 0;
+
+	if (ap_drv->in_use) {
+		rc = ap_drv->in_use(newapm, ap_perms.aqm);
+		if (rc)
+			rc = -EBUSY;
+	}
+
+	/* release the driver's module */
+	module_put(drv->owner);
+
+	return rc;
+}
+
+static int apmask_commit(unsigned long *newapm)
+{
+	int rc;
+	unsigned long reserved[BITS_TO_LONGS(AP_DEVICES)];
+
+	/*
+	 * Check if any bits in the apmask have been set which will
+	 * result in queues being removed from non-default drivers
+	 */
+	if (bitmap_andnot(reserved, newapm, ap_perms.apm, AP_DEVICES)) {
+		rc = bus_for_each_drv(&ap_bus_type, NULL, reserved,
+				      __verify_card_reservations);
+		if (rc)
+			return rc;
+	}
+
+	memcpy(ap_perms.apm, newapm, APMASKSIZE);
+
+	return 0;
+}
+
+static ssize_t apmask_store(struct bus_type *bus, const char *buf,
+			    size_t count)
+{
+	int rc, changes = 0;
+	DECLARE_BITMAP(newapm, AP_DEVICES);
+
+	if (mutex_lock_interruptible(&ap_perms_mutex))
+		return -ERESTARTSYS;
+
+	rc = ap_parse_bitmap_str(buf, ap_perms.apm, AP_DEVICES, newapm);
+	if (rc)
+		goto done;
+
+	changes = memcmp(ap_perms.apm, newapm, APMASKSIZE);
+	if (changes)
+		rc = apmask_commit(newapm);
+
+done:
+	mutex_unlock(&ap_perms_mutex);
+	if (rc)
+		return rc;
+
+	if (changes) {
+		ap_bus_revise_bindings();
+		ap_send_mask_changed_uevent(newapm, NULL);
+	}
+
+	return count;
+}
+
+static BUS_ATTR_RW(apmask);
+
+static ssize_t aqmask_show(struct bus_type *bus, char *buf)
+{
+	int rc;
+
+	if (mutex_lock_interruptible(&ap_perms_mutex))
+		return -ERESTARTSYS;
+	rc = scnprintf(buf, PAGE_SIZE,
+		       "0x%016lx%016lx%016lx%016lx\n",
+		       ap_perms.aqm[0], ap_perms.aqm[1],
+		       ap_perms.aqm[2], ap_perms.aqm[3]);
+	mutex_unlock(&ap_perms_mutex);
+
+	return rc;
+}
+
+static int __verify_queue_reservations(struct device_driver *drv, void *data)
+{
+	int rc = 0;
+	struct ap_driver *ap_drv = to_ap_drv(drv);
+	unsigned long *newaqm = (unsigned long *)data;
+
+	/*
+	 * increase the driver's module refcounter to be sure it is not
+	 * going away when we invoke the callback function.
+	 */
+	if (!try_module_get(drv->owner))
+		return 0;
+
+	if (ap_drv->in_use) {
+		rc = ap_drv->in_use(ap_perms.apm, newaqm);
+		if (rc)
+			rc = -EBUSY;
+	}
+
+	/* release the driver's module */
+	module_put(drv->owner);
+
+	return rc;
+}
+
+static int aqmask_commit(unsigned long *newaqm)
+{
+	int rc;
+	unsigned long reserved[BITS_TO_LONGS(AP_DOMAINS)];
+
+	/*
+	 * Check if any bits in the aqmask have been set which will
+	 * result in queues being removed from non-default drivers
+	 */
+	if (bitmap_andnot(reserved, newaqm, ap_perms.aqm, AP_DOMAINS)) {
+		rc = bus_for_each_drv(&ap_bus_type, NULL, reserved,
+				      __verify_queue_reservations);
+		if (rc)
+			return rc;
+	}
+
+	memcpy(ap_perms.aqm, newaqm, AQMASKSIZE);
+
+	return 0;
+}
+
+static ssize_t aqmask_store(struct bus_type *bus, const char *buf,
+			    size_t count)
+{
+	int rc, changes = 0;
+	DECLARE_BITMAP(newaqm, AP_DOMAINS);
+
+	if (mutex_lock_interruptible(&ap_perms_mutex))
+		return -ERESTARTSYS;
+
+	rc = ap_parse_bitmap_str(buf, ap_perms.aqm, AP_DOMAINS, newaqm);
+	if (rc)
+		goto done;
+
+	changes = memcmp(ap_perms.aqm, newaqm, APMASKSIZE);
+	if (changes)
+		rc = aqmask_commit(newaqm);
+
+done:
+	mutex_unlock(&ap_perms_mutex);
+	if (rc)
+		return rc;
+
+	if (changes) {
+		ap_bus_revise_bindings();
+		ap_send_mask_changed_uevent(NULL, newaqm);
+	}
+
+	return count;
+}
+
+static BUS_ATTR_RW(aqmask);
+
+static ssize_t scans_show(struct bus_type *bus, char *buf)
+{
+	return scnprintf(buf, PAGE_SIZE, "%llu\n",
+			 atomic64_read(&ap_scan_bus_count));
+}
+
+static ssize_t scans_store(struct bus_type *bus, const char *buf,
+			   size_t count)
+{
+	AP_DBF_INFO("%s force AP bus rescan\n", __func__);
+
+	ap_bus_force_rescan();
+
+	return count;
+}
+
+static BUS_ATTR_RW(scans);
+
+static ssize_t bindings_show(struct bus_type *bus, char *buf)
+{
+	int rc;
+	unsigned int apqns, n;
+
+	ap_calc_bound_apqns(&apqns, &n);
+	if (atomic64_read(&ap_scan_bus_count) >= 1 && n == apqns)
+		rc = scnprintf(buf, PAGE_SIZE, "%u/%u (complete)\n", n, apqns);
+	else
+		rc = scnprintf(buf, PAGE_SIZE, "%u/%u\n", n, apqns);
+
+	return rc;
+}
+
+static BUS_ATTR_RO(bindings);
+
+static struct attribute *ap_bus_attrs[] = {
+	&bus_attr_ap_domain.attr,
+	&bus_attr_ap_control_domain_mask.attr,
+	&bus_attr_ap_usage_domain_mask.attr,
+	&bus_attr_ap_adapter_mask.attr,
+	&bus_attr_config_time.attr,
+	&bus_attr_poll_thread.attr,
+	&bus_attr_ap_interrupts.attr,
+	&bus_attr_poll_timeout.attr,
+	&bus_attr_ap_max_domain_id.attr,
+	&bus_attr_ap_max_adapter_id.attr,
+	&bus_attr_apmask.attr,
+	&bus_attr_aqmask.attr,
+	&bus_attr_scans.attr,
+	&bus_attr_bindings.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(ap_bus);
+
+static struct bus_type ap_bus_type = {
+	.name = "ap",
+	.bus_groups = ap_bus_groups,
+	.match = &ap_bus_match,
+	.uevent = &ap_uevent,
+	.probe = ap_device_probe,
+	.remove = ap_device_remove,
+};
+
+/**
+ * ap_select_domain(): Select an AP domain if possible and we haven't
+ * already done so before.
+ */
+static void ap_select_domain(void)
+{
+	struct ap_queue_status status;
+	int card, dom;
+
+	/*
+	 * 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. */
+		goto out;
+	}
+	for (dom = 0; dom <= ap_max_domain_id; dom++) {
+		if (!ap_test_config_usage_domain(dom) ||
+		    !test_bit_inv(dom, ap_perms.aqm))
+			continue;
+		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(card, dom),
+					       ap_apft_available(),
+					       NULL);
+			if (status.response_code == AP_RESPONSE_NORMAL)
+				break;
+		}
+		if (card <= ap_max_adapter_id)
+			break;
+	}
+	if (dom <= ap_max_domain_id) {
+		ap_domain_index = dom;
+		AP_DBF_INFO("%s new default domain is %d\n",
+			    __func__, ap_domain_index);
+	}
+out:
+	spin_unlock_bh(&ap_domain_lock);
+}
+
+/*
+ * 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) {
+		AP_DBF_WARN("%s queue=%02x.%04x unsupported type %d\n",
+			    __func__, AP_QID_CARD(qid),
+			    AP_QID_QUEUE(qid), rawtype);
+		return 0;
+	}
+	/* up to CEX8 known and fully supported */
+	if (rawtype <= AP_DEVICE_TYPE_CEX8)
+		return rawtype;
+	/*
+	 * unknown new type > CEX8, check for compatibility
+	 * to the highest known and supported type which is
+	 * currently CEX8 with the help of the QACT function.
+	 */
+	if (ap_qact_available()) {
+		struct ap_queue_status status;
+		union ap_qact_ap_info apinfo = {0};
+
+		apinfo.mode = (func >> 26) & 0x07;
+		apinfo.cat = AP_DEVICE_TYPE_CEX8;
+		status = ap_qact(qid, 0, &apinfo);
+		if (status.response_code == AP_RESPONSE_NORMAL &&
+		    apinfo.cat >= AP_DEVICE_TYPE_CEX2A &&
+		    apinfo.cat <= AP_DEVICE_TYPE_CEX8)
+			comp_type = apinfo.cat;
+	}
+	if (!comp_type)
+		AP_DBF_WARN("%s queue=%02x.%04x unable to map type %d\n",
+			    __func__, AP_QID_CARD(qid),
+			    AP_QID_QUEUE(qid), rawtype);
+	else if (comp_type != rawtype)
+		AP_DBF_INFO("%s queue=%02x.%04x map type %d to %d\n",
+			    __func__, 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
+ */
+static int __match_card_device_with_id(struct device *dev, const void *data)
+{
+	return is_card_dev(dev) && to_ap_card(dev)->id == (int)(long)(void *)data;
+}
+
+/*
+ * Helper function to be used with bus_find_dev
+ * matches for the queue device with a given qid
+ */
+static int __match_queue_device_with_qid(struct device *dev, const void *data)
+{
+	return is_queue_dev(dev) && to_ap_queue(dev)->qid == (int)(long)data;
+}
+
+/*
+ * Helper function to be used with bus_find_dev
+ * matches any queue device with given queue id
+ */
+static int __match_queue_device_with_queue_id(struct device *dev, const void *data)
+{
+	return is_queue_dev(dev) &&
+		AP_QID_QUEUE(to_ap_queue(dev)->qid) == (int)(long)data;
+}
+
+/* Helper function for notify_config_changed */
+static int __drv_notify_config_changed(struct device_driver *drv, void *data)
+{
+	struct ap_driver *ap_drv = to_ap_drv(drv);
+
+	if (try_module_get(drv->owner)) {
+		if (ap_drv->on_config_changed)
+			ap_drv->on_config_changed(ap_qci_info, ap_qci_info_old);
+		module_put(drv->owner);
+	}
+
+	return 0;
+}
+
+/* Notify all drivers about an qci config change */
+static inline void notify_config_changed(void)
+{
+	bus_for_each_drv(&ap_bus_type, NULL, NULL,
+			 __drv_notify_config_changed);
+}
+
+/* Helper function for notify_scan_complete */
+static int __drv_notify_scan_complete(struct device_driver *drv, void *data)
+{
+	struct ap_driver *ap_drv = to_ap_drv(drv);
+
+	if (try_module_get(drv->owner)) {
+		if (ap_drv->on_scan_complete)
+			ap_drv->on_scan_complete(ap_qci_info,
+						 ap_qci_info_old);
+		module_put(drv->owner);
+	}
+
+	return 0;
+}
+
+/* Notify all drivers about bus scan complete */
+static inline void notify_scan_complete(void)
+{
+	bus_for_each_drv(&ap_bus_type, NULL, NULL,
+			 __drv_notify_scan_complete);
+}
+
+/*
+ * Helper function for ap_scan_bus().
+ * Remove card device and associated queue devices.
+ */
+static inline void ap_scan_rm_card_dev_and_queue_devs(struct ap_card *ac)
+{
+	bus_for_each_dev(&ap_bus_type, NULL,
+			 (void *)(long)ac->id,
+			 __ap_queue_devices_with_id_unregister);
+	device_unregister(&ac->ap_dev.device);
+}
+
+/*
+ * Helper function for ap_scan_bus().
+ * Does the scan bus job for all the domains within
+ * a valid adapter given by an ap_card ptr.
+ */
+static inline void ap_scan_domains(struct ap_card *ac)
+{
+	bool decfg, chkstop;
+	ap_qid_t qid;
+	unsigned int func;
+	struct device *dev;
+	struct ap_queue *aq;
+	int rc, dom, depth, type, ml;
+
+	/*
+	 * Go through the configuration for the domains and compare them
+	 * to the existing queue devices. Also take care of the config
+	 * and error state for the queue devices.
+	 */
+
+	for (dom = 0; dom <= ap_max_domain_id; dom++) {
+		qid = AP_MKQID(ac->id, dom);
+		dev = bus_find_device(&ap_bus_type, NULL,
+				      (void *)(long)qid,
+				      __match_queue_device_with_qid);
+		aq = dev ? to_ap_queue(dev) : NULL;
+		if (!ap_test_config_usage_domain(dom)) {
+			if (dev) {
+				AP_DBF_INFO("%s(%d,%d) not in config anymore, rm queue dev\n",
+					    __func__, ac->id, dom);
+				device_unregister(dev);
+				put_device(dev);
+			}
+			continue;
+		}
+		/* domain is valid, get info from this APQN */
+		if (!ap_queue_info(qid, &type, &func, &depth,
+				   &ml, &decfg, &chkstop)) {
+			if (aq) {
+				AP_DBF_INFO("%s(%d,%d) queue_info() failed, rm queue dev\n",
+					    __func__, ac->id, dom);
+				device_unregister(dev);
+				put_device(dev);
+			}
+			continue;
+		}
+		/* if no queue device exists, create a new one */
+		if (!aq) {
+			aq = ap_queue_create(qid, ac->ap_dev.device_type);
+			if (!aq) {
+				AP_DBF_WARN("%s(%d,%d) ap_queue_create() failed\n",
+					    __func__, ac->id, dom);
+				continue;
+			}
+			aq->card = ac;
+			aq->config = !decfg;
+			aq->chkstop = chkstop;
+			dev = &aq->ap_dev.device;
+			dev->bus = &ap_bus_type;
+			dev->parent = &ac->ap_dev.device;
+			dev_set_name(dev, "%02x.%04x", ac->id, dom);
+			/* register queue device */
+			rc = device_register(dev);
+			if (rc) {
+				AP_DBF_WARN("%s(%d,%d) device_register() failed\n",
+					    __func__, ac->id, dom);
+				goto put_dev_and_continue;
+			}
+			/* get it and thus adjust reference counter */
+			get_device(dev);
+			if (decfg)
+				AP_DBF_INFO("%s(%d,%d) new (decfg) queue dev created\n",
+					    __func__, ac->id, dom);
+			else if (chkstop)
+				AP_DBF_INFO("%s(%d,%d) new (chkstop) queue dev created\n",
+					    __func__, ac->id, dom);
+			else
+				AP_DBF_INFO("%s(%d,%d) new queue dev created\n",
+					    __func__, ac->id, dom);
+			goto put_dev_and_continue;
+		}
+		/* handle state changes on already existing queue device */
+		spin_lock_bh(&aq->lock);
+		/* checkstop state */
+		if (chkstop && !aq->chkstop) {
+			/* checkstop on */
+			aq->chkstop = true;
+			if (aq->dev_state > AP_DEV_STATE_UNINITIATED) {
+				aq->dev_state = AP_DEV_STATE_ERROR;
+				aq->last_err_rc = AP_RESPONSE_CHECKSTOPPED;
+			}
+			spin_unlock_bh(&aq->lock);
+			AP_DBF_DBG("%s(%d,%d) queue dev checkstop on\n",
+				   __func__, ac->id, dom);
+			/* 'receive' pending messages with -EAGAIN */
+			ap_flush_queue(aq);
+			goto put_dev_and_continue;
+		} else if (!chkstop && aq->chkstop) {
+			/* checkstop off */
+			aq->chkstop = false;
+			if (aq->dev_state > AP_DEV_STATE_UNINITIATED) {
+				aq->dev_state = AP_DEV_STATE_OPERATING;
+				aq->sm_state = AP_SM_STATE_RESET_START;
+			}
+			spin_unlock_bh(&aq->lock);
+			AP_DBF_DBG("%s(%d,%d) queue dev checkstop off\n",
+				   __func__, ac->id, dom);
+			goto put_dev_and_continue;
+		}
+		/* config state change */
+		if (decfg && aq->config) {
+			/* config off this queue device */
+			aq->config = false;
+			if (aq->dev_state > AP_DEV_STATE_UNINITIATED) {
+				aq->dev_state = AP_DEV_STATE_ERROR;
+				aq->last_err_rc = AP_RESPONSE_DECONFIGURED;
+			}
+			spin_unlock_bh(&aq->lock);
+			AP_DBF_DBG("%s(%d,%d) queue dev config off\n",
+				   __func__, ac->id, dom);
+			ap_send_config_uevent(&aq->ap_dev, aq->config);
+			/* 'receive' pending messages with -EAGAIN */
+			ap_flush_queue(aq);
+			goto put_dev_and_continue;
+		} else if (!decfg && !aq->config) {
+			/* config on this queue device */
+			aq->config = true;
+			if (aq->dev_state > AP_DEV_STATE_UNINITIATED) {
+				aq->dev_state = AP_DEV_STATE_OPERATING;
+				aq->sm_state = AP_SM_STATE_RESET_START;
+			}
+			spin_unlock_bh(&aq->lock);
+			AP_DBF_DBG("%s(%d,%d) queue dev config on\n",
+				   __func__, ac->id, dom);
+			ap_send_config_uevent(&aq->ap_dev, aq->config);
+			goto put_dev_and_continue;
+		}
+		/* handle other error states */
+		if (!decfg && aq->dev_state == AP_DEV_STATE_ERROR) {
+			spin_unlock_bh(&aq->lock);
+			/* 'receive' pending messages with -EAGAIN */
+			ap_flush_queue(aq);
+			/* re-init (with reset) the queue device */
+			ap_queue_init_state(aq);
+			AP_DBF_INFO("%s(%d,%d) queue dev reinit enforced\n",
+				    __func__, ac->id, dom);
+			goto put_dev_and_continue;
+		}
+		spin_unlock_bh(&aq->lock);
+put_dev_and_continue:
+		put_device(dev);
+	}
+}
+
+/*
+ * Helper function for ap_scan_bus().
+ * Does the scan bus job for the given adapter id.
+ */
+static inline void ap_scan_adapter(int ap)
+{
+	bool decfg, chkstop;
+	ap_qid_t qid;
+	unsigned int func;
+	struct device *dev;
+	struct ap_card *ac;
+	int rc, dom, depth, type, comp_type, ml;
+
+	/* Is there currently a card device for this adapter ? */
+	dev = bus_find_device(&ap_bus_type, NULL,
+			      (void *)(long)ap,
+			      __match_card_device_with_id);
+	ac = dev ? to_ap_card(dev) : NULL;
+
+	/* Adapter not in configuration ? */
+	if (!ap_test_config_card_id(ap)) {
+		if (ac) {
+			AP_DBF_INFO("%s(%d) ap not in config any more, rm card and queue devs\n",
+				    __func__, ap);
+			ap_scan_rm_card_dev_and_queue_devs(ac);
+			put_device(dev);
+		}
+		return;
+	}
+
+	/*
+	 * Adapter ap is valid in the current configuration. So do some checks:
+	 * If no card device exists, build one. If a card device exists, check
+	 * for type and functions changed. For all this we need to find a valid
+	 * APQN first.
+	 */
+
+	for (dom = 0; dom <= ap_max_domain_id; dom++)
+		if (ap_test_config_usage_domain(dom)) {
+			qid = AP_MKQID(ap, dom);
+			if (ap_queue_info(qid, &type, &func, &depth,
+					  &ml, &decfg, &chkstop))
+				break;
+		}
+	if (dom > ap_max_domain_id) {
+		/* Could not find a valid APQN for this adapter */
+		if (ac) {
+			AP_DBF_INFO("%s(%d) no type info (no APQN found), rm card and queue devs\n",
+				    __func__, ap);
+			ap_scan_rm_card_dev_and_queue_devs(ac);
+			put_device(dev);
+		} else {
+			AP_DBF_DBG("%s(%d) no type info (no APQN found), ignored\n",
+				   __func__, ap);
+		}
+		return;
+	}
+	if (!type) {
+		/* No apdater type info available, an unusable adapter */
+		if (ac) {
+			AP_DBF_INFO("%s(%d) no valid type (0) info, rm card and queue devs\n",
+				    __func__, ap);
+			ap_scan_rm_card_dev_and_queue_devs(ac);
+			put_device(dev);
+		} else {
+			AP_DBF_DBG("%s(%d) no valid type (0) info, ignored\n",
+				   __func__, ap);
+		}
+		return;
+	}
+
+	if (ac) {
+		/* Check APQN against existing card device for changes */
+		if (ac->raw_hwtype != type) {
+			AP_DBF_INFO("%s(%d) hwtype %d changed, rm card and queue devs\n",
+				    __func__, ap, type);
+			ap_scan_rm_card_dev_and_queue_devs(ac);
+			put_device(dev);
+			ac = NULL;
+		} else if (ac->functions != func) {
+			AP_DBF_INFO("%s(%d) functions 0x%08x changed, rm card and queue devs\n",
+				    __func__, ap, type);
+			ap_scan_rm_card_dev_and_queue_devs(ac);
+			put_device(dev);
+			ac = NULL;
+		} else {
+			/* handle checkstop state change */
+			if (chkstop && !ac->chkstop) {
+				/* checkstop on */
+				ac->chkstop = true;
+				AP_DBF_INFO("%s(%d) card dev checkstop on\n",
+					    __func__, ap);
+			} else if (!chkstop && ac->chkstop) {
+				/* checkstop off */
+				ac->chkstop = false;
+				AP_DBF_INFO("%s(%d) card dev checkstop off\n",
+					    __func__, ap);
+			}
+			/* handle config state change */
+			if (decfg && ac->config) {
+				ac->config = false;
+				AP_DBF_INFO("%s(%d) card dev config off\n",
+					    __func__, ap);
+				ap_send_config_uevent(&ac->ap_dev, ac->config);
+			} else if (!decfg && !ac->config) {
+				ac->config = true;
+				AP_DBF_INFO("%s(%d) card dev config on\n",
+					    __func__, ap);
+				ap_send_config_uevent(&ac->ap_dev, ac->config);
+			}
+		}
+	}
+
+	if (!ac) {
+		/* Build a new card device */
+		comp_type = ap_get_compatible_type(qid, type, func);
+		if (!comp_type) {
+			AP_DBF_WARN("%s(%d) type %d, can't get compatibility type\n",
+				    __func__, ap, type);
+			return;
+		}
+		ac = ap_card_create(ap, depth, type, comp_type, func, ml);
+		if (!ac) {
+			AP_DBF_WARN("%s(%d) ap_card_create() failed\n",
+				    __func__, ap);
+			return;
+		}
+		ac->config = !decfg;
+		ac->chkstop = chkstop;
+		dev = &ac->ap_dev.device;
+		dev->bus = &ap_bus_type;
+		dev->parent = ap_root_device;
+		dev_set_name(dev, "card%02x", ap);
+		/* maybe enlarge ap_max_msg_size to support this card */
+		if (ac->maxmsgsize > atomic_read(&ap_max_msg_size)) {
+			atomic_set(&ap_max_msg_size, ac->maxmsgsize);
+			AP_DBF_INFO("%s(%d) ap_max_msg_size update to %d byte\n",
+				    __func__, ap,
+				    atomic_read(&ap_max_msg_size));
+		}
+		/* Register the new card device with AP bus */
+		rc = device_register(dev);
+		if (rc) {
+			AP_DBF_WARN("%s(%d) device_register() failed\n",
+				    __func__, ap);
+			put_device(dev);
+			return;
+		}
+		/* get it and thus adjust reference counter */
+		get_device(dev);
+		if (decfg)
+			AP_DBF_INFO("%s(%d) new (decfg) card dev type=%d func=0x%08x created\n",
+				    __func__, ap, type, func);
+		else if (chkstop)
+			AP_DBF_INFO("%s(%d) new (chkstop) card dev type=%d func=0x%08x created\n",
+				    __func__, ap, type, func);
+		else
+			AP_DBF_INFO("%s(%d) new card dev type=%d func=0x%08x created\n",
+				    __func__, ap, type, func);
+	}
+
+	/* Verify the domains and the queue devices for this card */
+	ap_scan_domains(ac);
+
+	/* release the card device */
+	put_device(&ac->ap_dev.device);
+}
+
+/**
+ * ap_get_configuration - get the host AP configuration
+ *
+ * Stores the host AP configuration information returned from the previous call
+ * to Query Configuration Information (QCI), then retrieves and stores the
+ * current AP configuration returned from QCI.
+ *
+ * Return: true if the host AP configuration changed between calls to QCI;
+ * otherwise, return false.
+ */
+static bool ap_get_configuration(void)
+{
+	if (!ap_qci_info)	/* QCI not supported */
+		return false;
+
+	memcpy(ap_qci_info_old, ap_qci_info, sizeof(*ap_qci_info));
+	ap_fetch_qci_info(ap_qci_info);
+
+	return memcmp(ap_qci_info, ap_qci_info_old,
+		      sizeof(struct ap_config_info)) != 0;
+}
+
+/**
+ * ap_scan_bus(): Scan the AP bus for new devices
+ * Runs periodically, workqueue timer (ap_config_time)
+ * @unused: Unused pointer.
+ */
+static void ap_scan_bus(struct work_struct *unused)
+{
+	int ap, config_changed = 0;
+
+	/* config change notify */
+	config_changed = ap_get_configuration();
+	if (config_changed)
+		notify_config_changed();
+	ap_select_domain();
+
+	AP_DBF_DBG("%s running\n", __func__);
+
+	/* loop over all possible adapters */
+	for (ap = 0; ap <= ap_max_adapter_id; ap++)
+		ap_scan_adapter(ap);
+
+	/* scan complete notify */
+	if (config_changed)
+		notify_scan_complete();
+
+	/* check if there is at least one queue available with default domain */
+	if (ap_domain_index >= 0) {
+		struct device *dev =
+			bus_find_device(&ap_bus_type, NULL,
+					(void *)(long)ap_domain_index,
+					__match_queue_device_with_queue_id);
+		if (dev)
+			put_device(dev);
+		else
+			AP_DBF_INFO("%s no queue device with default domain %d available\n",
+				    __func__, ap_domain_index);
+	}
+
+	if (atomic64_inc_return(&ap_scan_bus_count) == 1) {
+		AP_DBF_DBG("%s init scan complete\n", __func__);
+		ap_send_init_scan_done_uevent();
+		ap_check_bindings_complete();
+	}
+
+	mod_timer(&ap_config_timer, jiffies + ap_config_time * HZ);
+}
+
+static void ap_config_timeout(struct timer_list *unused)
+{
+	queue_work(system_long_wq, &ap_scan_work);
+}
+
+static int __init ap_debug_init(void)
+{
+	ap_dbf_info = debug_register("ap", 2, 1,
+				     DBF_MAX_SPRINTF_ARGS * sizeof(long));
+	debug_register_view(ap_dbf_info, &debug_sprintf_view);
+	debug_set_level(ap_dbf_info, DBF_ERR);
+
+	return 0;
+}
+
+static void __init ap_perms_init(void)
+{
+	/* all resources usable if no kernel parameter string given */
+	memset(&ap_perms.ioctlm, 0xFF, sizeof(ap_perms.ioctlm));
+	memset(&ap_perms.apm, 0xFF, sizeof(ap_perms.apm));
+	memset(&ap_perms.aqm, 0xFF, sizeof(ap_perms.aqm));
+
+	/* apm kernel parameter string */
+	if (apm_str) {
+		memset(&ap_perms.apm, 0, sizeof(ap_perms.apm));
+		ap_parse_mask_str(apm_str, ap_perms.apm, AP_DEVICES,
+				  &ap_perms_mutex);
+	}
+
+	/* aqm kernel parameter string */
+	if (aqm_str) {
+		memset(&ap_perms.aqm, 0, sizeof(ap_perms.aqm));
+		ap_parse_mask_str(aqm_str, ap_perms.aqm, AP_DOMAINS,
+				  &ap_perms_mutex);
+	}
+}
+
+/**
+ * ap_module_init(): The module initialization code.
+ *
+ * Initializes the module.
+ */
+static int __init ap_module_init(void)
+{
+	int rc;
+
+	rc = ap_debug_init();
+	if (rc)
+		return rc;
+
+	if (!ap_instructions_available()) {
+		pr_warn("The hardware system does not support AP instructions\n");
+		return -ENODEV;
+	}
+
+	/* init ap_queue hashtable */
+	hash_init(ap_queues);
+
+	/* set up the AP permissions (ioctls, ap and aq masks) */
+	ap_perms_init();
+
+	/* Get AP configuration data if available */
+	ap_init_qci_info();
+
+	/* 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",
+			ap_domain_index);
+		ap_domain_index = -1;
+	}
+
+	/* enable interrupts if available */
+	if (ap_interrupts_available() && ap_useirq) {
+		rc = register_adapter_interrupt(&ap_airq);
+		ap_irq_flag = (rc == 0);
+	}
+
+	/* Create /sys/bus/ap. */
+	rc = bus_register(&ap_bus_type);
+	if (rc)
+		goto out;
+
+	/* Create /sys/devices/ap. */
+	ap_root_device = root_device_register("ap");
+	rc = PTR_ERR_OR_ZERO(ap_root_device);
+	if (rc)
+		goto out_bus;
+	ap_root_device->bus = &ap_bus_type;
+
+	/* Setup the AP bus rescan timer. */
+	timer_setup(&ap_config_timer, ap_config_timeout, 0);
+
+	/*
+	 * Setup the high resultion poll timer.
+	 * If we are running under z/VM adjust polling to z/VM polling rate.
+	 */
+	if (MACHINE_IS_VM)
+		poll_timeout = 1500000;
+	hrtimer_init(&ap_poll_timer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS);
+	ap_poll_timer.function = ap_poll_timeout;
+
+	/* Start the low priority AP bus poll thread. */
+	if (ap_thread_flag) {
+		rc = ap_poll_thread_start();
+		if (rc)
+			goto out_work;
+	}
+
+	queue_work(system_long_wq, &ap_scan_work);
+
+	return 0;
+
+out_work:
+	hrtimer_cancel(&ap_poll_timer);
+	root_device_unregister(ap_root_device);
+out_bus:
+	bus_unregister(&ap_bus_type);
+out:
+	if (ap_irq_flag)
+		unregister_adapter_interrupt(&ap_airq);
+	kfree(ap_qci_info);
+	return rc;
+}
+device_initcall(ap_module_init);