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