1 /*
2  * Copyright (c) 2014 Travis Geiselbrecht
3  *
4  * Use of this source code is governed by a MIT-style
5  * license that can be found in the LICENSE file or at
6  * https://opensource.org/licenses/MIT
7  */
8 #pragma once
9 
10 #include <lk/compiler.h>
11 #include <assert.h>
12 #include <lk/list.h>
13 #include <sys/types.h>
14 #include <dev/virtio/virtio_ring.h>
15 
16 /* detect a virtio mmio hardware block
17  * returns number of devices found */
18 int virtio_mmio_detect(void *ptr, uint count, const uint irqs[], size_t stride);
19 
20 #define MAX_VIRTIO_RINGS 4
21 
22 struct virtio_mmio_config;
23 
24 struct virtio_device {
25     bool valid;
26 
27     uint index;
28     uint irq;
29 
30     volatile struct virtio_mmio_config *mmio_config;
31     void *config_ptr;
32 
33     void *priv; /* a place for the driver to put private data */
34 
35     enum handler_return (*irq_driver_callback)(struct virtio_device *dev, uint ring, const struct vring_used_elem *e);
36     enum handler_return (*config_change_callback)(struct virtio_device *dev);
37 
38     /* virtio rings */
39     uint32_t active_rings_bitmap;
40     struct vring ring[MAX_VIRTIO_RINGS];
41 };
42 
43 void virtio_reset_device(struct virtio_device *dev);
44 void virtio_status_acknowledge_driver(struct virtio_device *dev);
45 void virtio_status_driver_ok(struct virtio_device *dev);
46 
47 /* api used by devices to interact with the virtio bus */
48 status_t virtio_alloc_ring(struct virtio_device *dev, uint index, uint16_t len) __NONNULL();
49 
50 /* add a descriptor at index desc_index to the free list on ring_index */
51 void virtio_free_desc(struct virtio_device *dev, uint ring_index, uint16_t desc_index);
52 
53 /* allocate a descriptor off the free list, 0xffff is error */
54 uint16_t virtio_alloc_desc(struct virtio_device *dev, uint ring_index);
55 
56 /* allocate a descriptor chain the free list */
57 struct vring_desc *virtio_alloc_desc_chain(struct virtio_device *dev, uint ring_index, size_t count, uint16_t *start_index);
58 
virtio_desc_index_to_desc(struct virtio_device * dev,uint ring_index,uint16_t desc_index)59 static inline struct vring_desc *virtio_desc_index_to_desc(struct virtio_device *dev, uint ring_index, uint16_t desc_index) {
60     DEBUG_ASSERT(desc_index != 0xffff);
61     return &dev->ring[ring_index].desc[desc_index];
62 }
63 
64 void virtio_dump_desc(const struct vring_desc *desc);
65 
66 /* submit a chain to the avail list */
67 void virtio_submit_chain(struct virtio_device *dev, uint ring_index, uint16_t desc_index);
68 
69 void virtio_kick(struct virtio_device *dev, uint ring_idnex);
70 
71 
72