stm32f103-template/rt-thread/components/drivers/virtio/virtio_queue.h

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2023-05-09 22:30:49 +08:00
/*
* Copyright (c) 2006-2023, RT-Thread Development Team
*
* SPDX-License-Identifier: Apache-2.0
*
* Change Logs:
* Date Author Notes
* 2021-11-11 GuEe-GUI the first version
*/
#ifndef __VIRTIO_QUEUE_H__
#define __VIRTIO_QUEUE_H__
#include <rtdef.h>
#define VIRTQ_DESC_F_NEXT 1 /* This marks a buffer as continuing via the next field. */
#define VIRTQ_DESC_F_WRITE 2 /* This marks a buffer as write-only (otherwise read-only). */
#define VIRTQ_DESC_F_INDIRECT 4 /* This means the buffer contains a list of buffer descriptors. */
/*
* The device uses this in used->flags to advise the driver: don't kick me
* when you add a buffer. It's unreliable, so it's simply an optimization.
*/
#define VIRTQ_USED_F_NO_NOTIFY 1
/*
* The driver uses this in avail->flags to advise the device: don't
* interrupt me when you consume a buffer. It's unreliable, so it's
* simply an optimization.
*/
#define VIRTQ_AVAIL_F_NO_INTERRUPT 1
/* Virtqueue descriptors: 16 bytes. These can chain together via "next". */
struct virtq_desc
{
rt_uint64_t addr; /* Address (guest-physical). */
rt_uint32_t len; /* Length. */
rt_uint16_t flags; /* The flags as indicated above. */
rt_uint16_t next; /* We chain unused descriptors via this, too */
};
struct virtq_avail
{
rt_uint16_t flags; /* Notifications */
rt_uint16_t idx; /* Where the driver would put the next descriptor entry in the ring (modulo the queue size) */
rt_uint16_t ring[];
/*
* Only if VIRTIO_F_RING_EVENT_IDX
* rt_uint16_t used_event;
*/
};
struct virtq_used_elem
{
rt_uint32_t id; /* Index of start of used descriptor chain. */
rt_uint32_t len; /* Total length of the descriptor chain which was written to. */
};
struct virtq_used
{
rt_uint16_t flags;
rt_uint16_t idx;
struct virtq_used_elem ring[];
/*
* Only if VIRTIO_F_RING_EVENT_IDX
* rt_uint16_t avail_event;
*/
};
struct virtq
{
rt_uint32_t num;
struct virtq_desc *desc;
struct virtq_avail *avail;
struct virtq_used *used;
/* Helper of driver */
rt_uint16_t used_idx;
rt_bool_t *free;
rt_size_t free_count;
};
#define VIRTQ_DESC_TOTAL_SIZE(ring_size) (sizeof(struct virtq_desc) * (ring_size))
/* flags, idx, used_event + ring * ring_size */
#define VIRTQ_AVAIL_TOTAL_SIZE(ring_size) (sizeof(rt_uint16_t) * 3 + sizeof(rt_uint16_t) * (ring_size))
/* flags, idx, avail_event + ring * ring_size */
#define VIRTQ_USED_TOTAL_SIZE(ring_size) (sizeof(rt_uint16_t) * 3 + sizeof(struct virtq_used_elem) * (ring_size))
#define VIRTQ_AVAIL_RES_SIZE (sizeof(rt_uint16_t)) /* used_event */
#define VIRTQ_USED_RES_SIZE (sizeof(rt_uint16_t)) /* avail_event */
#define VIRTQ_INVALID_DESC_ID RT_UINT16_MAX
#endif /* __VIRTIO_QUEUE_H__ */