msg_sm.c

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/*
 * msg_sm.c
 *
 * DSP-BIOS Bridge driver support functions for TI OMAP processors.
 *
 * Implements upper edge functions for Bridge message module.
 *
 * Copyright (C) 2005-2006 Texas Instruments, Inc.
 *
 * This package is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
 * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 */
#include <linux/types.h>

/*  ----------------------------------- DSP/BIOS Bridge */
#include <dspbridge/dbdefs.h>

/*  ----------------------------------- OS Adaptation Layer */
#include <dspbridge/sync.h>

/*  ----------------------------------- Platform Manager */
#include <dspbridge/dev.h>

/*  ----------------------------------- Others */
#include <dspbridge/io_sm.h>

/*  ----------------------------------- This */
#include <_msg_sm.h>
#include <dspbridge/dspmsg.h>

/*  ----------------------------------- Function Prototypes */
static int add_new_msg(struct list_head *msg_list);
static void delete_msg_mgr(struct msg_mgr *hmsg_mgr);
static void delete_msg_queue(struct msg_queue *msg_queue_obj, u32 num_to_dsp);
static void free_msg_list(struct list_head *msg_list);

/*
 *  ======== bridge_msg_create ========
 *      Create an object to manage message queues. Only one of these objects
 *      can exist per device object.
 */
int bridge_msg_create(struct msg_mgr **msg_man,
                 struct dev_object *hdev_obj,
                 msg_onexit msg_callback)
{
    struct msg_mgr *msg_mgr_obj;
    struct io_mgr *hio_mgr;
    int status = 0;

    if (!msg_man || !msg_callback || !hdev_obj)
        return -EFAULT;

    dev_get_io_mgr(hdev_obj, &hio_mgr);
    if (!hio_mgr)
        return -EFAULT;

    *msg_man = NULL;
    /* Allocate msg_ctrl manager object */
    msg_mgr_obj = kzalloc(sizeof(struct msg_mgr), GFP_KERNEL);
    if (!msg_mgr_obj)
        return -ENOMEM;

    msg_mgr_obj->on_exit = msg_callback;
    msg_mgr_obj->iomgr = hio_mgr;
    /* List of MSG_QUEUEs */
    INIT_LIST_HEAD(&msg_mgr_obj->queue_list);
    /*
     * Queues of message frames for messages to the DSP. Message
     * frames will only be added to the free queue when a
     * msg_queue object is created.
     */
    INIT_LIST_HEAD(&msg_mgr_obj->msg_free_list);
    INIT_LIST_HEAD(&msg_mgr_obj->msg_used_list);
    spin_lock_init(&msg_mgr_obj->msg_mgr_lock);

    /*
     * Create an event to be used by bridge_msg_put() in waiting
     * for an available free frame from the message manager.
     */
    msg_mgr_obj->sync_event =
        kzalloc(sizeof(struct sync_object), GFP_KERNEL);
    if (!msg_mgr_obj->sync_event) {
        kfree(msg_mgr_obj);
        return -ENOMEM;
    }
    sync_init_event(msg_mgr_obj->sync_event);

    *msg_man = msg_mgr_obj;

    return status;
}

/*
 *  ======== bridge_msg_create_queue ========
 *      Create a msg_queue for sending/receiving messages to/from a node
 *      on the DSP.
 */
int bridge_msg_create_queue(struct msg_mgr *hmsg_mgr, struct msg_queue **msgq,
                u32 msgq_id, u32 max_msgs, void *arg)
{
    u32 i;
    u32 num_allocated = 0;
    struct msg_queue *msg_q;
    int status = 0;

    if (!hmsg_mgr || msgq == NULL)
        return -EFAULT;

    *msgq = NULL;
    /* Allocate msg_queue object */
    msg_q = kzalloc(sizeof(struct msg_queue), GFP_KERNEL);
    if (!msg_q)
        return -ENOMEM;

    msg_q->max_msgs = max_msgs;
    msg_q->msg_mgr = hmsg_mgr;
    msg_q->arg = arg;   /* Node handle */
    msg_q->msgq_id = msgq_id;   /* Node env (not valid yet) */
    /* Queues of Message frames for messages from the DSP */
    INIT_LIST_HEAD(&msg_q->msg_free_list);
    INIT_LIST_HEAD(&msg_q->msg_used_list);

    /*  Create event that will be signalled when a message from
     *  the DSP is available. */
    msg_q->sync_event = kzalloc(sizeof(struct sync_object), GFP_KERNEL);
    if (!msg_q->sync_event) {
        status = -ENOMEM;
        goto out_err;

    }
    sync_init_event(msg_q->sync_event);

    /* Create a notification list for message ready notification. */
    msg_q->ntfy_obj = kmalloc(sizeof(struct ntfy_object), GFP_KERNEL);
    if (!msg_q->ntfy_obj) {
        status = -ENOMEM;
        goto out_err;
    }
    ntfy_init(msg_q->ntfy_obj);

    /*  Create events that will be used to synchronize cleanup
     *  when the object is deleted. sync_done will be set to
     *  unblock threads in MSG_Put() or MSG_Get(). sync_done_ack
     *  will be set by the unblocked thread to signal that it
     *  is unblocked and will no longer reference the object. */
    msg_q->sync_done = kzalloc(sizeof(struct sync_object), GFP_KERNEL);
    if (!msg_q->sync_done) {
        status = -ENOMEM;
        goto out_err;
    }
    sync_init_event(msg_q->sync_done);

    msg_q->sync_done_ack = kzalloc(sizeof(struct sync_object), GFP_KERNEL);
    if (!msg_q->sync_done_ack) {
        status = -ENOMEM;
        goto out_err;
    }
    sync_init_event(msg_q->sync_done_ack);

    /* Enter critical section */
    spin_lock_bh(&hmsg_mgr->msg_mgr_lock);
    /* Initialize message frames and put in appropriate queues */
    for (i = 0; i < max_msgs && !status; i++) {
        status = add_new_msg(&hmsg_mgr->msg_free_list);
        if (!status) {
            num_allocated++;
            status = add_new_msg(&msg_q->msg_free_list);
        }
    }
    if (status) {
        spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);
        goto out_err;
    }

    list_add_tail(&msg_q->list_elem, &hmsg_mgr->queue_list);
    *msgq = msg_q;
    /* Signal that free frames are now available */
    if (!list_empty(&hmsg_mgr->msg_free_list))
        sync_set_event(hmsg_mgr->sync_event);

    /* Exit critical section */
    spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);

    return 0;
out_err:
    delete_msg_queue(msg_q, num_allocated);
    return status;
}

/*
 *  ======== bridge_msg_delete ========
 *      Delete a msg_ctrl manager allocated in bridge_msg_create().
 */
void bridge_msg_delete(struct msg_mgr *hmsg_mgr)
{
    if (hmsg_mgr)
        delete_msg_mgr(hmsg_mgr);
}

/*
 *  ======== bridge_msg_delete_queue ========
 *      Delete a msg_ctrl queue allocated in bridge_msg_create_queue.
 */
void bridge_msg_delete_queue(struct msg_queue *msg_queue_obj)
{
    struct msg_mgr *hmsg_mgr;
    u32 io_msg_pend;

    if (!msg_queue_obj || !msg_queue_obj->msg_mgr)
        return;

    hmsg_mgr = msg_queue_obj->msg_mgr;
    msg_queue_obj->done = true;
    /*  Unblock all threads blocked in MSG_Get() or MSG_Put(). */
    io_msg_pend = msg_queue_obj->io_msg_pend;
    while (io_msg_pend) {
        /* Unblock thread */
        sync_set_event(msg_queue_obj->sync_done);
        /* Wait for acknowledgement */
        sync_wait_on_event(msg_queue_obj->sync_done_ack, SYNC_INFINITE);
        io_msg_pend = msg_queue_obj->io_msg_pend;
    }
    /* Remove message queue from hmsg_mgr->queue_list */
    spin_lock_bh(&hmsg_mgr->msg_mgr_lock);
    list_del(&msg_queue_obj->list_elem);
    /* Free the message queue object */
    delete_msg_queue(msg_queue_obj, msg_queue_obj->max_msgs);
    if (list_empty(&hmsg_mgr->msg_free_list))
        sync_reset_event(hmsg_mgr->sync_event);
    spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);
}

/*
 *  ======== bridge_msg_get ========
 *      Get a message from a msg_ctrl queue.
 */
int bridge_msg_get(struct msg_queue *msg_queue_obj,
              struct dsp_msg *pmsg, u32 utimeout)
{
    struct msg_frame *msg_frame_obj;
    struct msg_mgr *hmsg_mgr;
    struct sync_object *syncs[2];
    u32 index;
    int status = 0;

    if (!msg_queue_obj || pmsg == NULL)
        return -ENOMEM;

    hmsg_mgr = msg_queue_obj->msg_mgr;

    spin_lock_bh(&hmsg_mgr->msg_mgr_lock);
    /* If a message is already there, get it */
    if (!list_empty(&msg_queue_obj->msg_used_list)) {
        msg_frame_obj = list_first_entry(&msg_queue_obj->msg_used_list,
                struct msg_frame, list_elem);
        list_del(&msg_frame_obj->list_elem);
        *pmsg = msg_frame_obj->msg_data.msg;
        list_add_tail(&msg_frame_obj->list_elem,
                &msg_queue_obj->msg_free_list);
        if (list_empty(&msg_queue_obj->msg_used_list))
            sync_reset_event(msg_queue_obj->sync_event);
        spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);
        return 0;
    }

    if (msg_queue_obj->done) {
        spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);
        return -EPERM;
    }
    msg_queue_obj->io_msg_pend++;
    spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);

    /*
     * Wait til message is available, timeout, or done. We don't
     * have to schedule the DPC, since the DSP will send messages
     * when they are available.
     */
    syncs[0] = msg_queue_obj->sync_event;
    syncs[1] = msg_queue_obj->sync_done;
    status = sync_wait_on_multiple_events(syncs, 2, utimeout, &index);

    spin_lock_bh(&hmsg_mgr->msg_mgr_lock);
    if (msg_queue_obj->done) {
        msg_queue_obj->io_msg_pend--;
        spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);
        /*
         * Signal that we're not going to access msg_queue_obj
         * anymore, so it can be deleted.
         */
        sync_set_event(msg_queue_obj->sync_done_ack);
        return -EPERM;
    }
    if (!status && !list_empty(&msg_queue_obj->msg_used_list)) {
        /* Get msg from used list */
        msg_frame_obj = list_first_entry(&msg_queue_obj->msg_used_list,
                struct msg_frame, list_elem);
        list_del(&msg_frame_obj->list_elem);
        /* Copy message into pmsg and put frame on the free list */
        *pmsg = msg_frame_obj->msg_data.msg;
        list_add_tail(&msg_frame_obj->list_elem,
                &msg_queue_obj->msg_free_list);
    }
    msg_queue_obj->io_msg_pend--;
    /* Reset the event if there are still queued messages */
    if (!list_empty(&msg_queue_obj->msg_used_list))
        sync_set_event(msg_queue_obj->sync_event);

    spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);

    return status;
}

/*
 *  ======== bridge_msg_put ========
 *      Put a message onto a msg_ctrl queue.
 */
int bridge_msg_put(struct msg_queue *msg_queue_obj,
              const struct dsp_msg *pmsg, u32 utimeout)
{
    struct msg_frame *msg_frame_obj;
    struct msg_mgr *hmsg_mgr;
    struct sync_object *syncs[2];
    u32 index;
    int status;

    if (!msg_queue_obj || !pmsg || !msg_queue_obj->msg_mgr)
        return -EFAULT;

    hmsg_mgr = msg_queue_obj->msg_mgr;

    spin_lock_bh(&hmsg_mgr->msg_mgr_lock);

    /* If a message frame is available, use it */
    if (!list_empty(&hmsg_mgr->msg_free_list)) {
        msg_frame_obj = list_first_entry(&hmsg_mgr->msg_free_list,
                struct msg_frame, list_elem);
        list_del(&msg_frame_obj->list_elem);
        msg_frame_obj->msg_data.msg = *pmsg;
        msg_frame_obj->msg_data.msgq_id =
            msg_queue_obj->msgq_id;
        list_add_tail(&msg_frame_obj->list_elem,
                &hmsg_mgr->msg_used_list);
        hmsg_mgr->msgs_pending++;

        if (list_empty(&hmsg_mgr->msg_free_list))
            sync_reset_event(hmsg_mgr->sync_event);

        /* Release critical section before scheduling DPC */
        spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);
        /* Schedule a DPC, to do the actual data transfer: */
        iosm_schedule(hmsg_mgr->iomgr);
        return 0;
    }

    if (msg_queue_obj->done) {
        spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);
        return -EPERM;
    }
    msg_queue_obj->io_msg_pend++;

    spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);

    /* Wait til a free message frame is available, timeout, or done */
    syncs[0] = hmsg_mgr->sync_event;
    syncs[1] = msg_queue_obj->sync_done;
    status = sync_wait_on_multiple_events(syncs, 2, utimeout, &index);
    if (status)
        return status;

    /* Enter critical section */
    spin_lock_bh(&hmsg_mgr->msg_mgr_lock);
    if (msg_queue_obj->done) {
        msg_queue_obj->io_msg_pend--;
        /* Exit critical section */
        spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);
        /*
         * Signal that we're not going to access msg_queue_obj
         * anymore, so it can be deleted.
         */
        sync_set_event(msg_queue_obj->sync_done_ack);
        return -EPERM;
    }

    if (list_empty(&hmsg_mgr->msg_free_list)) {
        spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);
        return -EFAULT;
    }

    /* Get msg from free list */
    msg_frame_obj = list_first_entry(&hmsg_mgr->msg_free_list,
            struct msg_frame, list_elem);
    /*
     * Copy message into pmsg and put frame on the
     * used list.
     */
    list_del(&msg_frame_obj->list_elem);
    msg_frame_obj->msg_data.msg = *pmsg;
    msg_frame_obj->msg_data.msgq_id = msg_queue_obj->msgq_id;
    list_add_tail(&msg_frame_obj->list_elem, &hmsg_mgr->msg_used_list);
    hmsg_mgr->msgs_pending++;
    /*
     * Schedule a DPC, to do the actual
     * data transfer.
     */
    iosm_schedule(hmsg_mgr->iomgr);

    msg_queue_obj->io_msg_pend--;
    /* Reset event if there are still frames available */
    if (!list_empty(&hmsg_mgr->msg_free_list))
        sync_set_event(hmsg_mgr->sync_event);

    /* Exit critical section */
    spin_unlock_bh(&hmsg_mgr->msg_mgr_lock);

    return 0;
}

/*
 *  ======== bridge_msg_register_notify ========
 */
int bridge_msg_register_notify(struct msg_queue *msg_queue_obj,
                   u32 event_mask, u32 notify_type,
                   struct dsp_notification *hnotification)
{
    int status = 0;

    if (!msg_queue_obj || !hnotification) {
        status = -ENOMEM;
        goto func_end;
    }

    if (!(event_mask == DSP_NODEMESSAGEREADY || event_mask == 0)) {
        status = -EPERM;
        goto func_end;
    }

    if (notify_type != DSP_SIGNALEVENT) {
        status = -EBADR;
        goto func_end;
    }

    if (event_mask)
        status = ntfy_register(msg_queue_obj->ntfy_obj, hnotification,
                        event_mask, notify_type);
    else
        status = ntfy_unregister(msg_queue_obj->ntfy_obj,
                            hnotification);

    if (status == -EINVAL) {
        /*  Not registered. Ok, since we couldn't have known. Node
         *  notifications are split between node state change handled
         *  by NODE, and message ready handled by msg_ctrl. */
        status = 0;
    }
func_end:
    return status;
}

/*
 *  ======== bridge_msg_set_queue_id ========
 */
void bridge_msg_set_queue_id(struct msg_queue *msg_queue_obj, u32 msgq_id)
{
    /*
     *  A message queue must be created when a node is allocated,
     *  so that node_register_notify() can be called before the node
     *  is created. Since we don't know the node environment until the
     *  node is created, we need this function to set msg_queue_obj->msgq_id
     *  to the node environment, after the node is created.
     */
    if (msg_queue_obj)
        msg_queue_obj->msgq_id = msgq_id;
}

/*
 *  ======== add_new_msg ========
 *      Must be called in message manager critical section.
 */
static int add_new_msg(struct list_head *msg_list)
{
    struct msg_frame *pmsg;

    pmsg = kzalloc(sizeof(struct msg_frame), GFP_ATOMIC);
    if (!pmsg)
        return -ENOMEM;

    list_add_tail(&pmsg->list_elem, msg_list);

    return 0;
}

/*
 *  ======== delete_msg_mgr ========
 */
static void delete_msg_mgr(struct msg_mgr *hmsg_mgr)
{
    if (!hmsg_mgr)
        return;

    /* FIXME: free elements from queue_list? */
    free_msg_list(&hmsg_mgr->msg_free_list);
    free_msg_list(&hmsg_mgr->msg_used_list);
    kfree(hmsg_mgr->sync_event);
    kfree(hmsg_mgr);
}

/*
 *  ======== delete_msg_queue ========
 */
static void delete_msg_queue(struct msg_queue *msg_queue_obj, u32 num_to_dsp)
{
    struct msg_mgr *hmsg_mgr;
    struct msg_frame *pmsg, *tmp;
    u32 i;

    if (!msg_queue_obj || !msg_queue_obj->msg_mgr)
        return;

    hmsg_mgr = msg_queue_obj->msg_mgr;

    /* Pull off num_to_dsp message frames from Msg manager and free */
    i = 0;
    list_for_each_entry_safe(pmsg, tmp, &hmsg_mgr->msg_free_list,
            list_elem) {
        list_del(&pmsg->list_elem);
        kfree(pmsg);
        if (i++ >= num_to_dsp)
            break;
    }

    free_msg_list(&msg_queue_obj->msg_free_list);
    free_msg_list(&msg_queue_obj->msg_used_list);

    if (msg_queue_obj->ntfy_obj) {
        ntfy_delete(msg_queue_obj->ntfy_obj);
        kfree(msg_queue_obj->ntfy_obj);
    }

    kfree(msg_queue_obj->sync_event);
    kfree(msg_queue_obj->sync_done);
    kfree(msg_queue_obj->sync_done_ack);

    kfree(msg_queue_obj);
}

/*
 *  ======== free_msg_list ========
 */
static void free_msg_list(struct list_head *msg_list)
{
    struct msg_frame *pmsg, *tmp;

    if (!msg_list)
        return;

    list_for_each_entry_safe(pmsg, tmp, msg_list, list_elem) {
        list_del(&pmsg->list_elem);
        kfree(pmsg);
    }
}