drivers/s390/crypto/ap_queue.c - kernel/msm-4.19 - Gitiles

 /*
  * Copyright IBM Corp. 2016
  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
  *
  * Adjunct processor bus, queue related code.
  */

 #define KMSG_COMPONENT "ap"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

 #include <linux/init.h>
 #include <linux/slab.h>
 #include <asm/facility.h>

 #include "ap_bus.h"
 #include "ap_asm.h"

 /**
  * ap_queue_enable_interruption(): Enable interruption on an AP queue.
  * @qid: The AP queue number
  * @ind: the notification indicator byte
  *
  * Enables interruption on AP queue via ap_aqic(). Based on the return
  * value it waits a while and tests the AP queue if interrupts
  * have been switched on using ap_test_queue().
  */
 static int ap_queue_enable_interruption(struct ap_queue *aq, void *ind)
 {
 	struct ap_queue_status status;

 	status = ap_aqic(aq->qid, ind);
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 	case AP_RESPONSE_OTHERWISE_CHANGED:
 		return 0;
 	case AP_RESPONSE_Q_NOT_AVAIL:
 	case AP_RESPONSE_DECONFIGURED:
 	case AP_RESPONSE_CHECKSTOPPED:
 	case AP_RESPONSE_INVALID_ADDRESS:
 		pr_err("Registering adapter interrupts for AP device %02x.%04x failed\n",
 		       AP_QID_CARD(aq->qid),
 		       AP_QID_QUEUE(aq->qid));
 		return -EOPNOTSUPP;
 	case AP_RESPONSE_RESET_IN_PROGRESS:
 	case AP_RESPONSE_BUSY:
 	default:
 		return -EBUSY;
 	}
 }

 /**
  * __ap_send(): Send message to adjunct processor queue.
  * @qid: The AP queue number
  * @psmid: The program supplied message identifier
  * @msg: The message text
  * @length: The message length
  * @special: Special Bit
  *
  * Returns AP queue status structure.
  * Condition code 1 on NQAP can't happen because the L bit is 1.
  * Condition code 2 on NQAP also means the send is incomplete,
  * because a segment boundary was reached. The NQAP is repeated.
  */
 static inline struct ap_queue_status
 __ap_send(ap_qid_t qid, unsigned long long psmid, void *msg, size_t length,
 	  unsigned int special)
 {
 	if (special == 1)
 		qid |= 0x400000UL;
 	return ap_nqap(qid, psmid, msg, length);
 }

 int ap_send(ap_qid_t qid, unsigned long long psmid, void *msg, size_t length)
 {
 	struct ap_queue_status status;

 	status = __ap_send(qid, psmid, msg, length, 0);
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		return 0;
 	case AP_RESPONSE_Q_FULL:
 	case AP_RESPONSE_RESET_IN_PROGRESS:
 		return -EBUSY;
 	case AP_RESPONSE_REQ_FAC_NOT_INST:
 		return -EINVAL;
 	default:	/* Device is gone. */
 		return -ENODEV;
 	}
 }
 EXPORT_SYMBOL(ap_send);

 int ap_recv(ap_qid_t qid, unsigned long long *psmid, void *msg, size_t length)
 {
 	struct ap_queue_status status;

 	if (msg == NULL)
 		return -EINVAL;
 	status = ap_dqap(qid, psmid, msg, length);
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		return 0;
 	case AP_RESPONSE_NO_PENDING_REPLY:
 		if (status.queue_empty)
 			return -ENOENT;
 		return -EBUSY;
 	case AP_RESPONSE_RESET_IN_PROGRESS:
 		return -EBUSY;
 	default:
 		return -ENODEV;
 	}
 }
 EXPORT_SYMBOL(ap_recv);

 /* State machine definitions and helpers */

 static enum ap_wait ap_sm_nop(struct ap_queue *aq)
 {
 	return AP_WAIT_NONE;
 }

 /**
  * ap_sm_recv(): Receive pending reply messages from an AP queue but do
  *	not change the state of the device.
  * @aq: pointer to the AP queue
  *
  * Returns AP_WAIT_NONE, AP_WAIT_AGAIN, or AP_WAIT_INTERRUPT
  */
 static struct ap_queue_status ap_sm_recv(struct ap_queue *aq)
 {
 	struct ap_queue_status status;
 	struct ap_message *ap_msg;

 	status = ap_dqap(aq->qid, &aq->reply->psmid,
 			 aq->reply->message, aq->reply->length);
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		aq->queue_count--;
 		if (aq->queue_count > 0)
 			mod_timer(&aq->timeout,
 				  jiffies + aq->request_timeout);
 		list_for_each_entry(ap_msg, &aq->pendingq, list) {
 			if (ap_msg->psmid != aq->reply->psmid)
 				continue;
 			list_del_init(&ap_msg->list);
 			aq->pendingq_count--;
 			ap_msg->receive(aq, ap_msg, aq->reply);
 			break;
 		}
 	case AP_RESPONSE_NO_PENDING_REPLY:
 		if (!status.queue_empty || aq->queue_count <= 0)
 			break;
 		/* The card shouldn't forget requests but who knows. */
 		aq->queue_count = 0;
 		list_splice_init(&aq->pendingq, &aq->requestq);
 		aq->requestq_count += aq->pendingq_count;
 		aq->pendingq_count = 0;
 		break;
 	default:
 		break;
 	}
 	return status;
 }

 /**
  * ap_sm_read(): Receive pending reply messages from an AP queue.
  * @aq: pointer to the AP queue
  *
  * Returns AP_WAIT_NONE, AP_WAIT_AGAIN, or AP_WAIT_INTERRUPT
  */
 static enum ap_wait ap_sm_read(struct ap_queue *aq)
 {
 	struct ap_queue_status status;

 	if (!aq->reply)
 		return AP_WAIT_NONE;
 	status = ap_sm_recv(aq);
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		if (aq->queue_count > 0) {
 			aq->state = AP_STATE_WORKING;
 			return AP_WAIT_AGAIN;
 		}
 		aq->state = AP_STATE_IDLE;
 		return AP_WAIT_NONE;
 	case AP_RESPONSE_NO_PENDING_REPLY:
 		if (aq->queue_count > 0)
 			return AP_WAIT_INTERRUPT;
 		aq->state = AP_STATE_IDLE;
 		return AP_WAIT_NONE;
 	default:
 		aq->state = AP_STATE_BORKED;
 		return AP_WAIT_NONE;
 	}
 }

 /**
  * ap_sm_suspend_read(): Receive pending reply messages from an AP queue
  * without changing the device state in between. In suspend mode we don't
  * allow sending new requests, therefore just fetch pending replies.
  * @aq: pointer to the AP queue
  *
  * Returns AP_WAIT_NONE or AP_WAIT_AGAIN
  */
 static enum ap_wait ap_sm_suspend_read(struct ap_queue *aq)
 {
 	struct ap_queue_status status;

 	if (!aq->reply)
 		return AP_WAIT_NONE;
 	status = ap_sm_recv(aq);
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		if (aq->queue_count > 0)
 			return AP_WAIT_AGAIN;
 		/* fall through */
 	default:
 		return AP_WAIT_NONE;
 	}
 }

 /**
  * ap_sm_write(): Send messages from the request queue to an AP queue.
  * @aq: pointer to the AP queue
  *
  * Returns AP_WAIT_NONE, AP_WAIT_AGAIN, or AP_WAIT_INTERRUPT
  */
 static enum ap_wait ap_sm_write(struct ap_queue *aq)
 {
 	struct ap_queue_status status;
 	struct ap_message *ap_msg;

 	if (aq->requestq_count <= 0)
 		return AP_WAIT_NONE;
 	/* Start the next request on the queue. */
 	ap_msg = list_entry(aq->requestq.next, struct ap_message, list);
 	status = __ap_send(aq->qid, ap_msg->psmid,
 			   ap_msg->message, ap_msg->length, ap_msg->special);
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		aq->queue_count++;
 		if (aq->queue_count == 1)
 			mod_timer(&aq->timeout, jiffies + aq->request_timeout);
 		list_move_tail(&ap_msg->list, &aq->pendingq);
 		aq->requestq_count--;
 		aq->pendingq_count++;
 		if (aq->queue_count < aq->card->queue_depth) {
 			aq->state = AP_STATE_WORKING;
 			return AP_WAIT_AGAIN;
 		}
 		/* fall through */
 	case AP_RESPONSE_Q_FULL:
 		aq->state = AP_STATE_QUEUE_FULL;
 		return AP_WAIT_INTERRUPT;
 	case AP_RESPONSE_RESET_IN_PROGRESS:
 		aq->state = AP_STATE_RESET_WAIT;
 		return AP_WAIT_TIMEOUT;
 	case AP_RESPONSE_MESSAGE_TOO_BIG:
 	case AP_RESPONSE_REQ_FAC_NOT_INST:
 		list_del_init(&ap_msg->list);
 		aq->requestq_count--;
 		ap_msg->rc = -EINVAL;
 		ap_msg->receive(aq, ap_msg, NULL);
 		return AP_WAIT_AGAIN;
 	default:
 		aq->state = AP_STATE_BORKED;
 		return AP_WAIT_NONE;
 	}
 }

 /**
  * ap_sm_read_write(): Send and receive messages to/from an AP queue.
  * @aq: pointer to the AP queue
  *
  * Returns AP_WAIT_NONE, AP_WAIT_AGAIN, or AP_WAIT_INTERRUPT
  */
 static enum ap_wait ap_sm_read_write(struct ap_queue *aq)
 {
 	return min(ap_sm_read(aq), ap_sm_write(aq));
 }

 /**
  * ap_sm_reset(): Reset an AP queue.
  * @qid: The AP queue number
  *
  * Submit the Reset command to an AP queue.
  */
 static enum ap_wait ap_sm_reset(struct ap_queue *aq)
 {
 	struct ap_queue_status status;

 	status = ap_rapq(aq->qid);
 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 	case AP_RESPONSE_RESET_IN_PROGRESS:
 		aq->state = AP_STATE_RESET_WAIT;
 		aq->interrupt = AP_INTR_DISABLED;
 		return AP_WAIT_TIMEOUT;
 	case AP_RESPONSE_BUSY:
 		return AP_WAIT_TIMEOUT;
 	case AP_RESPONSE_Q_NOT_AVAIL:
 	case AP_RESPONSE_DECONFIGURED:
 	case AP_RESPONSE_CHECKSTOPPED:
 	default:
 		aq->state = AP_STATE_BORKED;
 		return AP_WAIT_NONE;
 	}
 }

 /**
  * ap_sm_reset_wait(): Test queue for completion of the reset operation
  * @aq: pointer to the AP queue
  *
  * Returns AP_POLL_IMMEDIATELY, AP_POLL_AFTER_TIMEROUT or 0.
  */
 static enum ap_wait ap_sm_reset_wait(struct ap_queue *aq)
 {
 	struct ap_queue_status status;
 	void *lsi_ptr;

 	if (aq->queue_count > 0 && aq->reply)
 		/* Try to read a completed message and get the status */
 		status = ap_sm_recv(aq);
 	else
 		/* Get the status with TAPQ */
 		status = ap_tapq(aq->qid, NULL);

 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		lsi_ptr = ap_airq_ptr();
 		if (lsi_ptr && ap_queue_enable_interruption(aq, lsi_ptr) == 0)
 			aq->state = AP_STATE_SETIRQ_WAIT;
 		else
 			aq->state = (aq->queue_count > 0) ?
 				AP_STATE_WORKING : AP_STATE_IDLE;
 		return AP_WAIT_AGAIN;
 	case AP_RESPONSE_BUSY:
 	case AP_RESPONSE_RESET_IN_PROGRESS:
 		return AP_WAIT_TIMEOUT;
 	case AP_RESPONSE_Q_NOT_AVAIL:
 	case AP_RESPONSE_DECONFIGURED:
 	case AP_RESPONSE_CHECKSTOPPED:
 	default:
 		aq->state = AP_STATE_BORKED;
 		return AP_WAIT_NONE;
 	}
 }

 /**
  * ap_sm_setirq_wait(): Test queue for completion of the irq enablement
  * @aq: pointer to the AP queue
  *
  * Returns AP_POLL_IMMEDIATELY, AP_POLL_AFTER_TIMEROUT or 0.
  */
 static enum ap_wait ap_sm_setirq_wait(struct ap_queue *aq)
 {
 	struct ap_queue_status status;

 	if (aq->queue_count > 0 && aq->reply)
 		/* Try to read a completed message and get the status */
 		status = ap_sm_recv(aq);
 	else
 		/* Get the status with TAPQ */
 		status = ap_tapq(aq->qid, NULL);

 	if (status.int_enabled == 1) {
 		/* Irqs are now enabled */
 		aq->interrupt = AP_INTR_ENABLED;
 		aq->state = (aq->queue_count > 0) ?
 			AP_STATE_WORKING : AP_STATE_IDLE;
 	}

 	switch (status.response_code) {
 	case AP_RESPONSE_NORMAL:
 		if (aq->queue_count > 0)
 			return AP_WAIT_AGAIN;
 		/* fallthrough */
 	case AP_RESPONSE_NO_PENDING_REPLY:
 		return AP_WAIT_TIMEOUT;
 	default:
 		aq->state = AP_STATE_BORKED;
 		return AP_WAIT_NONE;
 	}
 }

 /*
  * AP state machine jump table
  */
 static ap_func_t *ap_jumptable[NR_AP_STATES][NR_AP_EVENTS] = {
 	[AP_STATE_RESET_START] = {
 		[AP_EVENT_POLL] = ap_sm_reset,
 		[AP_EVENT_TIMEOUT] = ap_sm_nop,
 	},
 	[AP_STATE_RESET_WAIT] = {
 		[AP_EVENT_POLL] = ap_sm_reset_wait,
 		[AP_EVENT_TIMEOUT] = ap_sm_nop,
 	},
 	[AP_STATE_SETIRQ_WAIT] = {
 		[AP_EVENT_POLL] = ap_sm_setirq_wait,
 		[AP_EVENT_TIMEOUT] = ap_sm_nop,
 	},
 	[AP_STATE_IDLE] = {
 		[AP_EVENT_POLL] = ap_sm_write,
 		[AP_EVENT_TIMEOUT] = ap_sm_nop,
 	},
 	[AP_STATE_WORKING] = {
 		[AP_EVENT_POLL] = ap_sm_read_write,
 		[AP_EVENT_TIMEOUT] = ap_sm_reset,
 	},
 	[AP_STATE_QUEUE_FULL] = {
 		[AP_EVENT_POLL] = ap_sm_read,
 		[AP_EVENT_TIMEOUT] = ap_sm_reset,
 	},
 	[AP_STATE_SUSPEND_WAIT] = {
 		[AP_EVENT_POLL] = ap_sm_suspend_read,
 		[AP_EVENT_TIMEOUT] = ap_sm_nop,
 	},
 	[AP_STATE_BORKED] = {
 		[AP_EVENT_POLL] = ap_sm_nop,
 		[AP_EVENT_TIMEOUT] = ap_sm_nop,
 	},
 };

 enum ap_wait ap_sm_event(struct ap_queue *aq, enum ap_event event)
 {
 	return ap_jumptable[aq->state][event](aq);
 }

 enum ap_wait ap_sm_event_loop(struct ap_queue *aq, enum ap_event event)
 {
 	enum ap_wait wait;

 	while ((wait = ap_sm_event(aq, event)) == AP_WAIT_AGAIN)
 		;
 	return wait;
 }

 /*
  * Power management for queue devices
  */
 void ap_queue_suspend(struct ap_device *ap_dev)
 {
 	struct ap_queue *aq = to_ap_queue(&ap_dev->device);

 	/* Poll on the device until all requests are finished. */
 	spin_lock_bh(&aq->lock);
 	aq->state = AP_STATE_SUSPEND_WAIT;
 	while (ap_sm_event(aq, AP_EVENT_POLL) != AP_WAIT_NONE)
 		;
 	aq->state = AP_STATE_BORKED;
 	spin_unlock_bh(&aq->lock);
 }
 EXPORT_SYMBOL(ap_queue_suspend);

 void ap_queue_resume(struct ap_device *ap_dev)
 {
 }
 EXPORT_SYMBOL(ap_queue_resume);

 /*
  * AP queue related attributes.
  */
 static ssize_t ap_req_count_show(struct device *dev,
 				 struct device_attribute *attr,
 				 char *buf)
 {
 	struct ap_queue *aq = to_ap_queue(dev);
 	unsigned int req_cnt;

 	spin_lock_bh(&aq->lock);
 	req_cnt = aq->total_request_count;
 	spin_unlock_bh(&aq->lock);
 	return snprintf(buf, PAGE_SIZE, "%d\n", req_cnt);
 }

 static ssize_t ap_req_count_store(struct device *dev,
 				  struct device_attribute *attr,
 				  const char *buf, size_t count)
 {
 	struct ap_queue *aq = to_ap_queue(dev);

 	spin_lock_bh(&aq->lock);
 	aq->total_request_count = 0;
 	spin_unlock_bh(&aq->lock);

 	return count;
 }

 static DEVICE_ATTR(request_count, 0644, ap_req_count_show, ap_req_count_store);

 static ssize_t ap_requestq_count_show(struct device *dev,
 				      struct device_attribute *attr, char *buf)
 {
 	struct ap_queue *aq = to_ap_queue(dev);
 	unsigned int reqq_cnt = 0;

 	spin_lock_bh(&aq->lock);
 	reqq_cnt = aq->requestq_count;
 	spin_unlock_bh(&aq->lock);
 	return snprintf(buf, PAGE_SIZE, "%d\n", reqq_cnt);
 }

 static DEVICE_ATTR(requestq_count, 0444, ap_requestq_count_show, NULL);

 static ssize_t ap_pendingq_count_show(struct device *dev,
 				      struct device_attribute *attr, char *buf)
 {
 	struct ap_queue *aq = to_ap_queue(dev);
 	unsigned int penq_cnt = 0;

 	spin_lock_bh(&aq->lock);
 	penq_cnt = aq->pendingq_count;
 	spin_unlock_bh(&aq->lock);
 	return snprintf(buf, PAGE_SIZE, "%d\n", penq_cnt);
 }

 static DEVICE_ATTR(pendingq_count, 0444, ap_pendingq_count_show, NULL);

 static ssize_t ap_reset_show(struct device *dev,
 				      struct device_attribute *attr, char *buf)
 {
 	struct ap_queue *aq = to_ap_queue(dev);
 	int rc = 0;

 	spin_lock_bh(&aq->lock);
 	switch (aq->state) {
 	case AP_STATE_RESET_START:
 	case AP_STATE_RESET_WAIT:
 		rc = snprintf(buf, PAGE_SIZE, "Reset in progress.\n");
 		break;
 	case AP_STATE_WORKING:
 	case AP_STATE_QUEUE_FULL:
 		rc = snprintf(buf, PAGE_SIZE, "Reset Timer armed.\n");
 		break;
 	default:
 		rc = snprintf(buf, PAGE_SIZE, "No Reset Timer set.\n");
 	}
 	spin_unlock_bh(&aq->lock);
 	return rc;
 }

 static DEVICE_ATTR(reset, 0444, ap_reset_show, NULL);

 static ssize_t ap_interrupt_show(struct device *dev,
 				 struct device_attribute *attr, char *buf)
 {
 	struct ap_queue *aq = to_ap_queue(dev);
 	int rc = 0;

 	spin_lock_bh(&aq->lock);
 	if (aq->state == AP_STATE_SETIRQ_WAIT)
 		rc = snprintf(buf, PAGE_SIZE, "Enable Interrupt pending.\n");
 	else if (aq->interrupt == AP_INTR_ENABLED)
 		rc = snprintf(buf, PAGE_SIZE, "Interrupts enabled.\n");
 	else
 		rc = snprintf(buf, PAGE_SIZE, "Interrupts disabled.\n");
 	spin_unlock_bh(&aq->lock);
 	return rc;
 }

 static DEVICE_ATTR(interrupt, 0444, ap_interrupt_show, NULL);

 static struct attribute *ap_queue_dev_attrs[] = {
 	&dev_attr_request_count.attr,
 	&dev_attr_requestq_count.attr,
 	&dev_attr_pendingq_count.attr,
 	&dev_attr_reset.attr,
 	&dev_attr_interrupt.attr,
 	NULL
 };

 static struct attribute_group ap_queue_dev_attr_group = {
 	.attrs = ap_queue_dev_attrs
 };

 static const struct attribute_group *ap_queue_dev_attr_groups[] = {
 	&ap_queue_dev_attr_group,
 	NULL
 };

 static struct device_type ap_queue_type = {
 	.name = "ap_queue",
 	.groups = ap_queue_dev_attr_groups,
 };

 static void ap_queue_device_release(struct device *dev)
 {
 	kfree(to_ap_queue(dev));
 }

 struct ap_queue *ap_queue_create(ap_qid_t qid, int device_type)
 {
 	struct ap_queue *aq;

 	aq = kzalloc(sizeof(*aq), GFP_KERNEL);
 	if (!aq)
 		return NULL;
 	aq->ap_dev.device.release = ap_queue_device_release;
 	aq->ap_dev.device.type = &ap_queue_type;
 	aq->ap_dev.device_type = device_type;
 	/* CEX6 toleration: map to CEX5 */
 	if (device_type == AP_DEVICE_TYPE_CEX6)
 		aq->ap_dev.device_type = AP_DEVICE_TYPE_CEX5;
 	aq->qid = qid;
 	aq->state = AP_STATE_RESET_START;
 	aq->interrupt = AP_INTR_DISABLED;
 	spin_lock_init(&aq->lock);
 	INIT_LIST_HEAD(&aq->pendingq);
 	INIT_LIST_HEAD(&aq->requestq);
 	setup_timer(&aq->timeout, ap_request_timeout, (unsigned long) aq);

 	return aq;
 }

 void ap_queue_init_reply(struct ap_queue *aq, struct ap_message *reply)
 {
 	aq->reply = reply;

 	spin_lock_bh(&aq->lock);
 	ap_wait(ap_sm_event(aq, AP_EVENT_POLL));
 	spin_unlock_bh(&aq->lock);
 }
 EXPORT_SYMBOL(ap_queue_init_reply);

 /**
  * ap_queue_message(): Queue a request to an AP device.
  * @aq: The AP device to queue the message to
  * @ap_msg: The message that is to be added
  */
 void ap_queue_message(struct ap_queue *aq, struct ap_message *ap_msg)
 {
 	/* For asynchronous message handling a valid receive-callback
 	 * is required.
 	 */
 	BUG_ON(!ap_msg->receive);

 	spin_lock_bh(&aq->lock);
 	/* Queue the message. */
 	list_add_tail(&ap_msg->list, &aq->requestq);
 	aq->requestq_count++;
 	aq->total_request_count++;
 	atomic_inc(&aq->card->total_request_count);
 	/* Send/receive as many request from the queue as possible. */
 	ap_wait(ap_sm_event_loop(aq, AP_EVENT_POLL));
 	spin_unlock_bh(&aq->lock);
 }
 EXPORT_SYMBOL(ap_queue_message);

 /**
  * ap_cancel_message(): Cancel a crypto request.
  * @aq: The AP device that has the message queued
  * @ap_msg: The message that is to be removed
  *
  * Cancel a crypto request. This is done by removing the request
  * from the device pending or request queue. Note that the
  * request stays on the AP queue. When it finishes the message
  * reply will be discarded because the psmid can't be found.
  */
 void ap_cancel_message(struct ap_queue *aq, struct ap_message *ap_msg)
 {
 	struct ap_message *tmp;

 	spin_lock_bh(&aq->lock);
 	if (!list_empty(&ap_msg->list)) {
 		list_for_each_entry(tmp, &aq->pendingq, list)
 			if (tmp->psmid == ap_msg->psmid) {
 				aq->pendingq_count--;
 				goto found;
 			}
 		aq->requestq_count--;
 found:
 		list_del_init(&ap_msg->list);
 	}
 	spin_unlock_bh(&aq->lock);
 }
 EXPORT_SYMBOL(ap_cancel_message);

 /**
  * __ap_flush_queue(): Flush requests.
  * @aq: Pointer to the AP queue
  *
  * Flush all requests from the request/pending queue of an AP device.
  */
 static void __ap_flush_queue(struct ap_queue *aq)
 {
 	struct ap_message *ap_msg, *next;

 	list_for_each_entry_safe(ap_msg, next, &aq->pendingq, list) {
 		list_del_init(&ap_msg->list);
 		aq->pendingq_count--;
 		ap_msg->rc = -EAGAIN;
 		ap_msg->receive(aq, ap_msg, NULL);
 	}
 	list_for_each_entry_safe(ap_msg, next, &aq->requestq, list) {
 		list_del_init(&ap_msg->list);
 		aq->requestq_count--;
 		ap_msg->rc = -EAGAIN;
 		ap_msg->receive(aq, ap_msg, NULL);
 	}
 }

 void ap_flush_queue(struct ap_queue *aq)
 {
 	spin_lock_bh(&aq->lock);
 	__ap_flush_queue(aq);
 	spin_unlock_bh(&aq->lock);
 }
 EXPORT_SYMBOL(ap_flush_queue);

 void ap_queue_remove(struct ap_queue *aq)
 {
 	ap_flush_queue(aq);
 	del_timer_sync(&aq->timeout);
 }
 EXPORT_SYMBOL(ap_queue_remove);
	/*
	* Copyright IBM Corp. 2016
	* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
	*
	* Adjunct processor bus, queue related code.
	*/

	#define KMSG_COMPONENT "ap"
	#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

	#include <linux/init.h>
	#include <linux/slab.h>
	#include <asm/facility.h>

	#include "ap_bus.h"
	#include "ap_asm.h"

	/**
	* ap_queue_enable_interruption(): Enable interruption on an AP queue.
	* @qid: The AP queue number
	* @ind: the notification indicator byte
	*
	* Enables interruption on AP queue via ap_aqic(). Based on the return
	* value it waits a while and tests the AP queue if interrupts
	* have been switched on using ap_test_queue().
	*/
	static int ap_queue_enable_interruption(struct ap_queue aq, void ind)
	{
	struct ap_queue_status status;

	status = ap_aqic(aq->qid, ind);
	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
	case AP_RESPONSE_OTHERWISE_CHANGED:
	return 0;
	case AP_RESPONSE_Q_NOT_AVAIL:
	case AP_RESPONSE_DECONFIGURED:
	case AP_RESPONSE_CHECKSTOPPED:
	case AP_RESPONSE_INVALID_ADDRESS:
	pr_err("Registering adapter interrupts for AP device %02x.%04x failed\n",
	AP_QID_CARD(aq->qid),
	AP_QID_QUEUE(aq->qid));
	return -EOPNOTSUPP;
	case AP_RESPONSE_RESET_IN_PROGRESS:
	case AP_RESPONSE_BUSY:
	default:
	return -EBUSY;
	}
	}

	/**
	* __ap_send(): Send message to adjunct processor queue.
	* @qid: The AP queue number
	* @psmid: The program supplied message identifier
	* @msg: The message text
	* @length: The message length
	* @special: Special Bit
	*
	* Returns AP queue status structure.
	* Condition code 1 on NQAP can't happen because the L bit is 1.
	* Condition code 2 on NQAP also means the send is incomplete,
	* because a segment boundary was reached. The NQAP is repeated.
	*/
	static inline struct ap_queue_status
	__ap_send(ap_qid_t qid, unsigned long long psmid, void *msg, size_t length,
	unsigned int special)
	{
	if (special == 1)
	qid \|= 0x400000UL;
	return ap_nqap(qid, psmid, msg, length);
	}

	int ap_send(ap_qid_t qid, unsigned long long psmid, void *msg, size_t length)
	{
	struct ap_queue_status status;

	status = __ap_send(qid, psmid, msg, length, 0);
	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
	return 0;
	case AP_RESPONSE_Q_FULL:
	case AP_RESPONSE_RESET_IN_PROGRESS:
	return -EBUSY;
	case AP_RESPONSE_REQ_FAC_NOT_INST:
	return -EINVAL;
	default: /* Device is gone. */
	return -ENODEV;
	}
	}
	EXPORT_SYMBOL(ap_send);

	int ap_recv(ap_qid_t qid, unsigned long long psmid, void msg, size_t length)
	{
	struct ap_queue_status status;

	if (msg == NULL)
	return -EINVAL;
	status = ap_dqap(qid, psmid, msg, length);
	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
	return 0;
	case AP_RESPONSE_NO_PENDING_REPLY:
	if (status.queue_empty)
	return -ENOENT;
	return -EBUSY;
	case AP_RESPONSE_RESET_IN_PROGRESS:
	return -EBUSY;
	default:
	return -ENODEV;
	}
	}
	EXPORT_SYMBOL(ap_recv);

	/* State machine definitions and helpers */

	static enum ap_wait ap_sm_nop(struct ap_queue *aq)
	{
	return AP_WAIT_NONE;
	}

	/**
	* ap_sm_recv(): Receive pending reply messages from an AP queue but do
	* not change the state of the device.
	* @aq: pointer to the AP queue
	*
	* Returns AP_WAIT_NONE, AP_WAIT_AGAIN, or AP_WAIT_INTERRUPT
	*/
	static struct ap_queue_status ap_sm_recv(struct ap_queue *aq)
	{
	struct ap_queue_status status;
	struct ap_message *ap_msg;

	status = ap_dqap(aq->qid, &aq->reply->psmid,
	aq->reply->message, aq->reply->length);
	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
	aq->queue_count--;
	if (aq->queue_count > 0)
	mod_timer(&aq->timeout,
	jiffies + aq->request_timeout);
	list_for_each_entry(ap_msg, &aq->pendingq, list) {
	if (ap_msg->psmid != aq->reply->psmid)
	continue;
	list_del_init(&ap_msg->list);
	aq->pendingq_count--;
	ap_msg->receive(aq, ap_msg, aq->reply);
	break;
	}
	case AP_RESPONSE_NO_PENDING_REPLY:
	if (!status.queue_empty \|\| aq->queue_count <= 0)
	break;
	/* The card shouldn't forget requests but who knows. */
	aq->queue_count = 0;
	list_splice_init(&aq->pendingq, &aq->requestq);
	aq->requestq_count += aq->pendingq_count;
	aq->pendingq_count = 0;
	break;
	default:
	break;
	}
	return status;
	}

	/**
	* ap_sm_read(): Receive pending reply messages from an AP queue.
	* @aq: pointer to the AP queue
	*
	* Returns AP_WAIT_NONE, AP_WAIT_AGAIN, or AP_WAIT_INTERRUPT
	*/
	static enum ap_wait ap_sm_read(struct ap_queue *aq)
	{
	struct ap_queue_status status;

	if (!aq->reply)
	return AP_WAIT_NONE;
	status = ap_sm_recv(aq);
	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
	if (aq->queue_count > 0) {
	aq->state = AP_STATE_WORKING;
	return AP_WAIT_AGAIN;
	}
	aq->state = AP_STATE_IDLE;
	return AP_WAIT_NONE;
	case AP_RESPONSE_NO_PENDING_REPLY:
	if (aq->queue_count > 0)
	return AP_WAIT_INTERRUPT;
	aq->state = AP_STATE_IDLE;
	return AP_WAIT_NONE;
	default:
	aq->state = AP_STATE_BORKED;
	return AP_WAIT_NONE;
	}
	}

	/**
	* ap_sm_suspend_read(): Receive pending reply messages from an AP queue
	* without changing the device state in between. In suspend mode we don't
	* allow sending new requests, therefore just fetch pending replies.
	* @aq: pointer to the AP queue
	*
	* Returns AP_WAIT_NONE or AP_WAIT_AGAIN
	*/
	static enum ap_wait ap_sm_suspend_read(struct ap_queue *aq)
	{
	struct ap_queue_status status;

	if (!aq->reply)
	return AP_WAIT_NONE;
	status = ap_sm_recv(aq);
	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
	if (aq->queue_count > 0)
	return AP_WAIT_AGAIN;
	/* fall through */
	default:
	return AP_WAIT_NONE;
	}
	}

	/**
	* ap_sm_write(): Send messages from the request queue to an AP queue.
	* @aq: pointer to the AP queue
	*
	* Returns AP_WAIT_NONE, AP_WAIT_AGAIN, or AP_WAIT_INTERRUPT
	*/
	static enum ap_wait ap_sm_write(struct ap_queue *aq)
	{
	struct ap_queue_status status;
	struct ap_message *ap_msg;

	if (aq->requestq_count <= 0)
	return AP_WAIT_NONE;
	/* Start the next request on the queue. */
	ap_msg = list_entry(aq->requestq.next, struct ap_message, list);
	status = __ap_send(aq->qid, ap_msg->psmid,
	ap_msg->message, ap_msg->length, ap_msg->special);
	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
	aq->queue_count++;
	if (aq->queue_count == 1)
	mod_timer(&aq->timeout, jiffies + aq->request_timeout);
	list_move_tail(&ap_msg->list, &aq->pendingq);
	aq->requestq_count--;
	aq->pendingq_count++;
	if (aq->queue_count < aq->card->queue_depth) {
	aq->state = AP_STATE_WORKING;
	return AP_WAIT_AGAIN;
	}
	/* fall through */
	case AP_RESPONSE_Q_FULL:
	aq->state = AP_STATE_QUEUE_FULL;
	return AP_WAIT_INTERRUPT;
	case AP_RESPONSE_RESET_IN_PROGRESS:
	aq->state = AP_STATE_RESET_WAIT;
	return AP_WAIT_TIMEOUT;
	case AP_RESPONSE_MESSAGE_TOO_BIG:
	case AP_RESPONSE_REQ_FAC_NOT_INST:
	list_del_init(&ap_msg->list);
	aq->requestq_count--;
	ap_msg->rc = -EINVAL;
	ap_msg->receive(aq, ap_msg, NULL);
	return AP_WAIT_AGAIN;
	default:
	aq->state = AP_STATE_BORKED;
	return AP_WAIT_NONE;
	}
	}

	/**
	* ap_sm_read_write(): Send and receive messages to/from an AP queue.
	* @aq: pointer to the AP queue
	*
	* Returns AP_WAIT_NONE, AP_WAIT_AGAIN, or AP_WAIT_INTERRUPT
	*/
	static enum ap_wait ap_sm_read_write(struct ap_queue *aq)
	{
	return min(ap_sm_read(aq), ap_sm_write(aq));
	}

	/**
	* ap_sm_reset(): Reset an AP queue.
	* @qid: The AP queue number
	*
	* Submit the Reset command to an AP queue.
	*/
	static enum ap_wait ap_sm_reset(struct ap_queue *aq)
	{
	struct ap_queue_status status;

	status = ap_rapq(aq->qid);
	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
	case AP_RESPONSE_RESET_IN_PROGRESS:
	aq->state = AP_STATE_RESET_WAIT;
	aq->interrupt = AP_INTR_DISABLED;
	return AP_WAIT_TIMEOUT;
	case AP_RESPONSE_BUSY:
	return AP_WAIT_TIMEOUT;
	case AP_RESPONSE_Q_NOT_AVAIL:
	case AP_RESPONSE_DECONFIGURED:
	case AP_RESPONSE_CHECKSTOPPED:
	default:
	aq->state = AP_STATE_BORKED;
	return AP_WAIT_NONE;
	}
	}

	/**
	* ap_sm_reset_wait(): Test queue for completion of the reset operation
	* @aq: pointer to the AP queue
	*
	* Returns AP_POLL_IMMEDIATELY, AP_POLL_AFTER_TIMEROUT or 0.
	*/
	static enum ap_wait ap_sm_reset_wait(struct ap_queue *aq)
	{
	struct ap_queue_status status;
	void *lsi_ptr;

	if (aq->queue_count > 0 && aq->reply)
	/* Try to read a completed message and get the status */
	status = ap_sm_recv(aq);
	else
	/* Get the status with TAPQ */
	status = ap_tapq(aq->qid, NULL);

	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
	lsi_ptr = ap_airq_ptr();
	if (lsi_ptr && ap_queue_enable_interruption(aq, lsi_ptr) == 0)
	aq->state = AP_STATE_SETIRQ_WAIT;
	else
	aq->state = (aq->queue_count > 0) ?
	AP_STATE_WORKING : AP_STATE_IDLE;
	return AP_WAIT_AGAIN;
	case AP_RESPONSE_BUSY:
	case AP_RESPONSE_RESET_IN_PROGRESS:
	return AP_WAIT_TIMEOUT;
	case AP_RESPONSE_Q_NOT_AVAIL:
	case AP_RESPONSE_DECONFIGURED:
	case AP_RESPONSE_CHECKSTOPPED:
	default:
	aq->state = AP_STATE_BORKED;
	return AP_WAIT_NONE;
	}
	}

	/**
	* ap_sm_setirq_wait(): Test queue for completion of the irq enablement
	* @aq: pointer to the AP queue
	*
	* Returns AP_POLL_IMMEDIATELY, AP_POLL_AFTER_TIMEROUT or 0.
	*/
	static enum ap_wait ap_sm_setirq_wait(struct ap_queue *aq)
	{
	struct ap_queue_status status;

	if (aq->queue_count > 0 && aq->reply)
	/* Try to read a completed message and get the status */
	status = ap_sm_recv(aq);
	else
	/* Get the status with TAPQ */
	status = ap_tapq(aq->qid, NULL);

	if (status.int_enabled == 1) {
	/* Irqs are now enabled */
	aq->interrupt = AP_INTR_ENABLED;
	aq->state = (aq->queue_count > 0) ?
	AP_STATE_WORKING : AP_STATE_IDLE;
	}

	switch (status.response_code) {
	case AP_RESPONSE_NORMAL:
	if (aq->queue_count > 0)
	return AP_WAIT_AGAIN;
	/* fallthrough */
	case AP_RESPONSE_NO_PENDING_REPLY:
	return AP_WAIT_TIMEOUT;
	default:
	aq->state = AP_STATE_BORKED;
	return AP_WAIT_NONE;
	}
	}

	/*
	* AP state machine jump table
	*/
	static ap_func_t *ap_jumptable[NR_AP_STATES][NR_AP_EVENTS] = {
	[AP_STATE_RESET_START] = {
	[AP_EVENT_POLL] = ap_sm_reset,
	[AP_EVENT_TIMEOUT] = ap_sm_nop,
	},
	[AP_STATE_RESET_WAIT] = {
	[AP_EVENT_POLL] = ap_sm_reset_wait,
	[AP_EVENT_TIMEOUT] = ap_sm_nop,
	},
	[AP_STATE_SETIRQ_WAIT] = {
	[AP_EVENT_POLL] = ap_sm_setirq_wait,
	[AP_EVENT_TIMEOUT] = ap_sm_nop,
	},
	[AP_STATE_IDLE] = {
	[AP_EVENT_POLL] = ap_sm_write,
	[AP_EVENT_TIMEOUT] = ap_sm_nop,
	},
	[AP_STATE_WORKING] = {
	[AP_EVENT_POLL] = ap_sm_read_write,
	[AP_EVENT_TIMEOUT] = ap_sm_reset,
	},
	[AP_STATE_QUEUE_FULL] = {
	[AP_EVENT_POLL] = ap_sm_read,
	[AP_EVENT_TIMEOUT] = ap_sm_reset,
	},
	[AP_STATE_SUSPEND_WAIT] = {
	[AP_EVENT_POLL] = ap_sm_suspend_read,
	[AP_EVENT_TIMEOUT] = ap_sm_nop,
	},
	[AP_STATE_BORKED] = {
	[AP_EVENT_POLL] = ap_sm_nop,
	[AP_EVENT_TIMEOUT] = ap_sm_nop,
	},
	};

	enum ap_wait ap_sm_event(struct ap_queue *aq, enum ap_event event)
	{
	return ap_jumptable[aq->state][event](aq);
	}

	enum ap_wait ap_sm_event_loop(struct ap_queue *aq, enum ap_event event)
	{
	enum ap_wait wait;

	while ((wait = ap_sm_event(aq, event)) == AP_WAIT_AGAIN)
	;
	return wait;
	}

	/*
	* Power management for queue devices
	*/
	void ap_queue_suspend(struct ap_device *ap_dev)
	{
	struct ap_queue *aq = to_ap_queue(&ap_dev->device);

	/* Poll on the device until all requests are finished. */
	spin_lock_bh(&aq->lock);
	aq->state = AP_STATE_SUSPEND_WAIT;
	while (ap_sm_event(aq, AP_EVENT_POLL) != AP_WAIT_NONE)
	;
	aq->state = AP_STATE_BORKED;
	spin_unlock_bh(&aq->lock);
	}
	EXPORT_SYMBOL(ap_queue_suspend);

	void ap_queue_resume(struct ap_device *ap_dev)
	{
	}
	EXPORT_SYMBOL(ap_queue_resume);

	/*
	* AP queue related attributes.
	*/
	static ssize_t ap_req_count_show(struct device *dev,
	struct device_attribute *attr,
	char *buf)
	{
	struct ap_queue *aq = to_ap_queue(dev);
	unsigned int req_cnt;

	spin_lock_bh(&aq->lock);
	req_cnt = aq->total_request_count;
	spin_unlock_bh(&aq->lock);
	return snprintf(buf, PAGE_SIZE, "%d\n", req_cnt);
	}

	static ssize_t ap_req_count_store(struct device *dev,
	struct device_attribute *attr,
	const char *buf, size_t count)
	{
	struct ap_queue *aq = to_ap_queue(dev);

	spin_lock_bh(&aq->lock);
	aq->total_request_count = 0;
	spin_unlock_bh(&aq->lock);

	return count;
	}

	static DEVICE_ATTR(request_count, 0644, ap_req_count_show, ap_req_count_store);

	static ssize_t ap_requestq_count_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct ap_queue *aq = to_ap_queue(dev);
	unsigned int reqq_cnt = 0;

	spin_lock_bh(&aq->lock);
	reqq_cnt = aq->requestq_count;
	spin_unlock_bh(&aq->lock);
	return snprintf(buf, PAGE_SIZE, "%d\n", reqq_cnt);
	}

	static DEVICE_ATTR(requestq_count, 0444, ap_requestq_count_show, NULL);

	static ssize_t ap_pendingq_count_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct ap_queue *aq = to_ap_queue(dev);
	unsigned int penq_cnt = 0;

	spin_lock_bh(&aq->lock);
	penq_cnt = aq->pendingq_count;
	spin_unlock_bh(&aq->lock);
	return snprintf(buf, PAGE_SIZE, "%d\n", penq_cnt);
	}

	static DEVICE_ATTR(pendingq_count, 0444, ap_pendingq_count_show, NULL);

	static ssize_t ap_reset_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct ap_queue *aq = to_ap_queue(dev);
	int rc = 0;

	spin_lock_bh(&aq->lock);
	switch (aq->state) {
	case AP_STATE_RESET_START:
	case AP_STATE_RESET_WAIT:
	rc = snprintf(buf, PAGE_SIZE, "Reset in progress.\n");
	break;
	case AP_STATE_WORKING:
	case AP_STATE_QUEUE_FULL:
	rc = snprintf(buf, PAGE_SIZE, "Reset Timer armed.\n");
	break;
	default:
	rc = snprintf(buf, PAGE_SIZE, "No Reset Timer set.\n");
	}
	spin_unlock_bh(&aq->lock);
	return rc;
	}

	static DEVICE_ATTR(reset, 0444, ap_reset_show, NULL);

	static ssize_t ap_interrupt_show(struct device *dev,
	struct device_attribute attr, char buf)
	{
	struct ap_queue *aq = to_ap_queue(dev);
	int rc = 0;

	spin_lock_bh(&aq->lock);
	if (aq->state == AP_STATE_SETIRQ_WAIT)
	rc = snprintf(buf, PAGE_SIZE, "Enable Interrupt pending.\n");
	else if (aq->interrupt == AP_INTR_ENABLED)
	rc = snprintf(buf, PAGE_SIZE, "Interrupts enabled.\n");
	else
	rc = snprintf(buf, PAGE_SIZE, "Interrupts disabled.\n");
	spin_unlock_bh(&aq->lock);
	return rc;
	}

	static DEVICE_ATTR(interrupt, 0444, ap_interrupt_show, NULL);

	static struct attribute *ap_queue_dev_attrs[] = {
	&dev_attr_request_count.attr,
	&dev_attr_requestq_count.attr,
	&dev_attr_pendingq_count.attr,
	&dev_attr_reset.attr,
	&dev_attr_interrupt.attr,
	NULL
	};

	static struct attribute_group ap_queue_dev_attr_group = {
	.attrs = ap_queue_dev_attrs
	};

	static const struct attribute_group *ap_queue_dev_attr_groups[] = {
	&ap_queue_dev_attr_group,
	NULL
	};

	static struct device_type ap_queue_type = {
	.name = "ap_queue",
	.groups = ap_queue_dev_attr_groups,
	};

	static void ap_queue_device_release(struct device *dev)
	{
	kfree(to_ap_queue(dev));
	}

	struct ap_queue *ap_queue_create(ap_qid_t qid, int device_type)
	{
	struct ap_queue *aq;

	aq = kzalloc(sizeof(*aq), GFP_KERNEL);
	if (!aq)
	return NULL;
	aq->ap_dev.device.release = ap_queue_device_release;
	aq->ap_dev.device.type = &ap_queue_type;
	aq->ap_dev.device_type = device_type;
	/* CEX6 toleration: map to CEX5 */
	if (device_type == AP_DEVICE_TYPE_CEX6)
	aq->ap_dev.device_type = AP_DEVICE_TYPE_CEX5;
	aq->qid = qid;
	aq->state = AP_STATE_RESET_START;
	aq->interrupt = AP_INTR_DISABLED;
	spin_lock_init(&aq->lock);
	INIT_LIST_HEAD(&aq->pendingq);
	INIT_LIST_HEAD(&aq->requestq);
	setup_timer(&aq->timeout, ap_request_timeout, (unsigned long) aq);

	return aq;
	}

	void ap_queue_init_reply(struct ap_queue aq, struct ap_message reply)
	{
	aq->reply = reply;

	spin_lock_bh(&aq->lock);
	ap_wait(ap_sm_event(aq, AP_EVENT_POLL));
	spin_unlock_bh(&aq->lock);
	}
	EXPORT_SYMBOL(ap_queue_init_reply);

	/**
	* ap_queue_message(): Queue a request to an AP device.
	* @aq: The AP device to queue the message to
	* @ap_msg: The message that is to be added
	*/
	void ap_queue_message(struct ap_queue aq, struct ap_message ap_msg)
	{
	/* For asynchronous message handling a valid receive-callback
	* is required.
	*/
	BUG_ON(!ap_msg->receive);

	spin_lock_bh(&aq->lock);
	/* Queue the message. */
	list_add_tail(&ap_msg->list, &aq->requestq);
	aq->requestq_count++;
	aq->total_request_count++;
	atomic_inc(&aq->card->total_request_count);
	/* Send/receive as many request from the queue as possible. */
	ap_wait(ap_sm_event_loop(aq, AP_EVENT_POLL));
	spin_unlock_bh(&aq->lock);
	}
	EXPORT_SYMBOL(ap_queue_message);

	/**
	* ap_cancel_message(): Cancel a crypto request.
	* @aq: The AP device that has the message queued
	* @ap_msg: The message that is to be removed
	*
	* Cancel a crypto request. This is done by removing the request
	* from the device pending or request queue. Note that the
	* request stays on the AP queue. When it finishes the message
	* reply will be discarded because the psmid can't be found.
	*/
	void ap_cancel_message(struct ap_queue aq, struct ap_message ap_msg)
	{
	struct ap_message *tmp;

	spin_lock_bh(&aq->lock);
	if (!list_empty(&ap_msg->list)) {
	list_for_each_entry(tmp, &aq->pendingq, list)
	if (tmp->psmid == ap_msg->psmid) {
	aq->pendingq_count--;
	goto found;
	}
	aq->requestq_count--;
	found:
	list_del_init(&ap_msg->list);
	}
	spin_unlock_bh(&aq->lock);
	}
	EXPORT_SYMBOL(ap_cancel_message);

	/**
	* __ap_flush_queue(): Flush requests.
	* @aq: Pointer to the AP queue
	*
	* Flush all requests from the request/pending queue of an AP device.
	*/
	static void __ap_flush_queue(struct ap_queue *aq)
	{
	struct ap_message ap_msg, next;

	list_for_each_entry_safe(ap_msg, next, &aq->pendingq, list) {
	list_del_init(&ap_msg->list);
	aq->pendingq_count--;
	ap_msg->rc = -EAGAIN;
	ap_msg->receive(aq, ap_msg, NULL);
	}
	list_for_each_entry_safe(ap_msg, next, &aq->requestq, list) {
	list_del_init(&ap_msg->list);
	aq->requestq_count--;
	ap_msg->rc = -EAGAIN;
	ap_msg->receive(aq, ap_msg, NULL);
	}
	}

	void ap_flush_queue(struct ap_queue *aq)
	{
	spin_lock_bh(&aq->lock);
	__ap_flush_queue(aq);
	spin_unlock_bh(&aq->lock);
	}
	EXPORT_SYMBOL(ap_flush_queue);

	void ap_queue_remove(struct ap_queue *aq)
	{
	ap_flush_queue(aq);
	del_timer_sync(&aq->timeout);
	}
	EXPORT_SYMBOL(ap_queue_remove);