linux-imx

/* Virtio ring implementation.

 *

 *  Copyright 2007 Rusty Russell IBM Corporation

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License as published by

 *  the Free Software Foundation; either version 2 of the License, or

 *  (at your option) any later version.

 *

 *  This program is distributed in the hope that it will be useful,

 *  but WITHOUT ANY WARRANTY; without even the implied warranty of

 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 *  GNU General Public License for more details.

 *

 *  You should have received a copy of the GNU General Public License

 *  along with this program; if not, write to the Free Software

 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#include <linux/virtio.h>

#include <linux/virtio_ring.h>

#include <linux/virtio_config.h>

#include <linux/device.h>

#include <linux/slab.h>

#include <linux/module.h>

#include <linux/hrtimer.h>

#include <linux/dma-mapping.h>

#include <xen/xen.h>

​

#ifdef DEBUG

/* For development, we want to crash whenever the ring is screwed. */

#define BAD_RING(_vq, fmt, args...)             \

    do {                            \

        dev_err(&(_vq)->vq.vdev->dev,           \

            "%s:"fmt, (_vq)->vq.name, ##args);  \

        BUG();                      \

    } while (0)

/* Caller is supposed to guarantee no reentry. */

#define START_USE(_vq)                      \

    do {                            \

        if ((_vq)->in_use)              \

            panic("%s:in_use = %i\n",       \

                  (_vq)->vq.name, (_vq)->in_use);   \

        (_vq)->in_use = __LINE__;           \

    } while (0)

#define END_USE(_vq) \

    do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; } while(0)

#define LAST_ADD_TIME_UPDATE(_vq)               \

    do {                            \

        ktime_t now = ktime_get();          \

                                \

        /* No kick or get, with .1 second between?  Warn. */ \

        if ((_vq)->last_add_time_valid)         \

            WARN_ON(ktime_to_ms(ktime_sub(now,  \

                (_vq)->last_add_time)) > 100);  \

        (_vq)->last_add_time = now;         \

        (_vq)->last_add_time_valid = true;      \

    } while (0)

#define LAST_ADD_TIME_CHECK(_vq)                \

    do {                            \

        if ((_vq)->last_add_time_valid) {       \

            WARN_ON(ktime_to_ms(ktime_sub(ktime_get(), \

                      (_vq)->last_add_time)) > 100); \

        }                       \