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32 results

ap_queue.c

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  • ap_queue.c 17.90 KiB
    /*
     * 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.irq_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)
    {
    	struct ap_queue *aq = to_ap_queue(dev);
    
    	if (!list_empty(&aq->list)) {
    		spin_lock_bh(&ap_list_lock);
    		list_del_init(&aq->list);
    		spin_unlock_bh(&ap_list_lock);
    	}
    	kfree(aq);
    }
    
    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);