// SPDX-License-Identifier: GPL-2.0
/*
 * 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_debug.h"

static void __ap_flush_queue(struct ap_queue *aq);

/**
 * 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;
        struct ap_qirq_ctrl qirqctrl = { 0 };

        qirqctrl.ir = 1;
        qirqctrl.isc = AP_ISC;
        status = ap_aqic(aq->qid, qirqctrl, 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;
                }
                /* fall through */
        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_REMOVE] = {
                [AP_EVENT_POLL] = ap_sm_nop,
                [AP_EVENT_TIMEOUT] = ap_sm_nop,
        },
        [AP_STATE_UNBOUND] = {
                [AP_EVENT_POLL] = ap_sm_nop,
                [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 request_count_show(struct device *dev,
                                  struct device_attribute *attr,
                                  char *buf)
{
        struct ap_queue *aq = to_ap_queue(dev);
        u64 req_cnt;

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

static ssize_t request_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_RW(request_count);

static ssize_t 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_RO(requestq_count);

static ssize_t 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_RO(pendingq_count);

static ssize_t 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 ssize_t reset_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);
        __ap_flush_queue(aq);
        aq->state = AP_STATE_RESET_START;
        ap_wait(ap_sm_event(aq, AP_EVENT_POLL));
        spin_unlock_bh(&aq->lock);

        AP_DBF(DBF_INFO, "reset queue=%02x.%04x triggered by user\n",
               AP_QID_CARD(aq->qid), AP_QID_QUEUE(aq->qid));

        return count;
}

static DEVICE_ATTR_RW(reset);

static ssize_t 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_RO(interrupt);

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;
        aq->qid = qid;
        aq->state = AP_STATE_UNBOUND;
        aq->interrupt = AP_INTR_DISABLED;
        spin_lock_init(&aq->lock);
        INIT_LIST_HEAD(&aq->list);
        INIT_LIST_HEAD(&aq->pendingq);
        INIT_LIST_HEAD(&aq->requestq);
        timer_setup(&aq->timeout, ap_request_timeout, 0);

        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++;
        atomic64_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);
        }
        aq->queue_count = 0;
}

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_prepare_remove(struct ap_queue *aq)
{
        spin_lock_bh(&aq->lock);
        /* flush queue */
        __ap_flush_queue(aq);
        /* set REMOVE state to prevent new messages are queued in */
        aq->state = AP_STATE_REMOVE;
        spin_unlock_bh(&aq->lock);
        del_timer_sync(&aq->timeout);
}

void ap_queue_remove(struct ap_queue *aq)
{
        /*
         * all messages have been flushed and the state is
         * AP_STATE_REMOVE. Now reset with zero which also
         * clears the irq registration and move the state
         * to AP_STATE_UNBOUND to signal that this queue
         * is not used by any driver currently.
         */
        spin_lock_bh(&aq->lock);
        ap_zapq(aq->qid);
        aq->state = AP_STATE_UNBOUND;
        spin_unlock_bh(&aq->lock);
}

void ap_queue_init_state(struct ap_queue *aq)
{
        spin_lock_bh(&aq->lock);
        aq->state = AP_STATE_RESET_START;
        ap_wait(ap_sm_event(aq, AP_EVENT_POLL));
        spin_unlock_bh(&aq->lock);
}
EXPORT_SYMBOL(ap_queue_init_state);