source: mainline/uspace/srv/hw/bus/usb/hcd/virtual/hc.c@ b8a3cda

/*
 * Copyright (c) 2010 Vojtech Horky
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup usb
 * @{
 */
/** @file
 * @brief Virtual HC (implementation).
 */

#include <ipc/ipc.h>
#include <adt/list.h>
#include <bool.h>
#include <async.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <str_error.h>

#include <usbvirt/hub.h>

#include "vhcd.h"
#include "hc.h"
#include "devices.h"

#define USLEEP_BASE (500 * 1000)

#define USLEEP_VAR 5000

#define SHORTENING_VAR 15

#define PROB_OUTCOME_BABBLE 5
#define PROB_OUTCOME_CRCERROR 7

#define PROB_TEST(var, new_value, prob, number) \
        do { \
                if (((number) % (prob)) == 0) { \
                        var = (new_value); \
                } \
        } while (0)

static link_t transaction_to_device_list;
static link_t transaction_from_device_list;

#define TRANSACTION_FORMAT "T[%d:%d (%d)]"
#define TRANSACTION_PRINTF(t) \
        (t).target.address, (t).target.endpoint, \
        (int)(t).len

#define transaction_get_instance(lnk) \
        list_get_instance(lnk, transaction_t, link)

static inline unsigned int pseudo_random(unsigned int *seed)
{
        *seed = ((*seed) * 873511) % 22348977 + 7;
        return ((*seed) >> 8);
}

/** Call transaction callback.
 * Calling this callback informs the backend that transaction was processed.
 */
static void process_transaction_with_outcome(transaction_t * transaction,
    usb_transaction_outcome_t outcome)
{
        dprintf("processing transaction " TRANSACTION_FORMAT ", outcome: %s",
            TRANSACTION_PRINTF(*transaction),
            usb_str_transaction_outcome(outcome));
        
        transaction->callback(transaction->buffer, transaction->len, outcome,
            transaction->callback_arg);
}

/** Host controller manager main function.
 */
void hc_manager(void)
{
        list_initialize(&transaction_to_device_list);
        list_initialize(&transaction_from_device_list);
        
        static unsigned int seed = 4573;
        
        printf("%s: transaction processor ready.\n", NAME);
        
        while (true) {
                async_usleep(USLEEP_BASE + (pseudo_random(&seed) % USLEEP_VAR));
                
                if (list_empty(&transaction_to_device_list)) {
                        continue;
                }
                
                link_t *first_transaction_link = transaction_to_device_list.next;
                transaction_t *transaction
                    = transaction_get_instance(first_transaction_link);
                list_remove(first_transaction_link);
                
                usb_transaction_outcome_t outcome;
                outcome = virtdev_send_to_all(transaction);
                
                process_transaction_with_outcome(transaction, outcome);
                
                free(transaction);
        }
}

/** Create new transaction
 */
static transaction_t *transaction_create(usbvirt_transaction_type_t type,
    usb_target_t target,
    void * buffer, size_t len,
    hc_transaction_done_callback_t callback, void * arg)
{
        transaction_t * transaction = malloc(sizeof(transaction_t));
        
        list_initialize(&transaction->link);
        transaction->type = type;
        transaction->target = target;
        transaction->buffer = buffer;
        transaction->len = len;
        transaction->callback = callback;
        transaction->callback_arg = arg;
        
        return transaction;
}

/** Add transaction directioned towards the device.
 */
void hc_add_transaction_to_device(bool setup, usb_target_t target,
    void * buffer, size_t len,
    hc_transaction_done_callback_t callback, void * arg)
{
        transaction_t *transaction = transaction_create(
            setup ? USBVIRT_TRANSACTION_SETUP : USBVIRT_TRANSACTION_OUT, target,
            buffer, len, callback, arg);
        list_append(&transaction->link, &transaction_to_device_list);
}

/** Add transaction directioned from the device.
 */
void hc_add_transaction_from_device(usb_target_t target,
    void * buffer, size_t len,
    hc_transaction_done_callback_t callback, void * arg)
{
        transaction_t *transaction = transaction_create(USBVIRT_TRANSACTION_IN,
            target, buffer, len, callback, arg);
        list_append(&transaction->link, &transaction_from_device_list);
}

/** Fill data to existing transaction from device.
 */
int hc_fillin_transaction_from_device(usb_target_t target,
    void * buffer, size_t len)
{
        dprintf("finding transaction to fill data in (%d:%d)...",
            target.address, target.endpoint);
        int rc;
        
        /*
         * Find correct transaction envelope in the list.
         */
        if (list_empty(&transaction_from_device_list)) {
                rc = ENOENT;
                goto leave;
        }
        
        transaction_t *transaction = NULL;
        link_t *pos = transaction_from_device_list.next;
        
        while (pos != &transaction_from_device_list) {
                transaction_t *t = transaction_get_instance(pos);
                if (usb_target_same(t->target, target)) {
                        transaction = t;
                        break;
                }
                pos = pos->next;
        }
        if (transaction == NULL) {
                rc = ENOENT;
                goto leave;
        }
        
        /*
         * Remove the transaction from the list as it will be processed now.
         */
        list_remove(&transaction->link);
        
        if (transaction->len < len) {
                process_transaction_with_outcome(transaction, USB_OUTCOME_BABBLE);
                rc = ENOMEM;
                goto leave;
        }
        
        /*
         * Copy the data and finish processing the transaction.
         */
        transaction->len = len;
        memcpy(transaction->buffer, buffer, len);
        
        process_transaction_with_outcome(transaction, USB_OUTCOME_OK);
        
        dprintf("  ...transaction " TRANSACTION_FORMAT " sent back",
            TRANSACTION_PRINTF(*transaction));
        
        
        free(transaction);
        rc = EOK;
        
leave:
        dprintf("  ...fill-in transaction: %s", str_error(rc));
        
        return rc;
}

/**
 * @}
 */