1 #ifndef _LINUX_VIRTIO_H
2 #define _LINUX_VIRTIO_H
3 /* Everything a virtio driver needs to work with any particular virtio
4 * implementation. */
5 #include <linux/types.h>
6 #include <linux/scatterlist.h>
7 #include <linux/spinlock.h>
8 #include <linux/device.h>
9 #include <linux/mod_devicetable.h>
10 #include <linux/gfp.h>
11 #include <linux/vringh.h>
12
13 /**
14 * virtqueue - a queue to register buffers for sending or receiving.
15 * @list: the chain of virtqueues for this device
16 * @callback: the function to call when buffers are consumed (can be NULL).
17 * @name: the name of this virtqueue (mainly for debugging)
18 * @vdev: the virtio device this queue was created for.
19 * @priv: a pointer for the virtqueue implementation to use.
20 * @index: the zero-based ordinal number for this queue.
21 * @num_free: number of elements we expect to be able to fit.
22 *
23 * A note on @num_free: with indirect buffers, each buffer needs one
24 * element in the queue, otherwise a buffer will need one element per
25 * sg element.
26 */
27 struct virtqueue {
28 struct list_head list;
29 void (*callback)(struct virtqueue *vq);
30 const char *name;
31 struct virtio_device *vdev;
32 unsigned int index;
33 unsigned int num_free;
34 void *priv;
35 };
36
37 int virtqueue_add_buf(struct virtqueue *vq,
38 struct scatterlist sg[],
39 unsigned int out_num,
40 unsigned int in_num,
41 void *data,
42 gfp_t gfp);
43
44 int virtqueue_add_outbuf(struct virtqueue *vq,
45 struct scatterlist sg[], unsigned int num,
46 void *data,
47 gfp_t gfp);
48
49 int virtqueue_add_inbuf(struct virtqueue *vq,
50 struct scatterlist sg[], unsigned int num,
51 void *data,
52 gfp_t gfp);
53
54 int virtqueue_add_sgs(struct virtqueue *vq,
55 struct scatterlist *sgs[],
56 unsigned int out_sgs,
57 unsigned int in_sgs,
58 void *data,
59 gfp_t gfp);
60
61 void virtqueue_kick(struct virtqueue *vq);
62
63 bool virtqueue_kick_prepare(struct virtqueue *vq);
64
65 void virtqueue_notify(struct virtqueue *vq);
66
67 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
68
69 void virtqueue_disable_cb(struct virtqueue *vq);
70
71 bool virtqueue_enable_cb(struct virtqueue *vq);
72
73 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
74
75 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
76
77 unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
78
79 /**
80 * virtio_device - representation of a device using virtio
81 * @index: unique position on the virtio bus
82 * @dev: underlying device.
83 * @id: the device type identification (used to match it with a driver).
84 * @config: the configuration ops for this device.
85 * @vringh_config: configuration ops for host vrings.
86 * @vqs: the list of virtqueues for this device.
87 * @features: the features supported by both driver and device.
88 * @priv: private pointer for the driver's use.
89 */
90 struct virtio_device {
91 int index;
92 struct device dev;
93 struct virtio_device_id id;
94 const struct virtio_config_ops *config;
95 const struct vringh_config_ops *vringh_config;
96 struct list_head vqs;
97 /* Note that this is a Linux set_bit-style bitmap. */
98 unsigned long features[1];
99 void *priv;
100 };
101
dev_to_virtio(struct device * _dev)102 static inline struct virtio_device *dev_to_virtio(struct device *_dev)
103 {
104 return container_of(_dev, struct virtio_device, dev);
105 }
106
107 int register_virtio_device(struct virtio_device *dev);
108 void unregister_virtio_device(struct virtio_device *dev);
109
110 /**
111 * virtio_driver - operations for a virtio I/O driver
112 * @driver: underlying device driver (populate name and owner).
113 * @id_table: the ids serviced by this driver.
114 * @feature_table: an array of feature numbers supported by this driver.
115 * @feature_table_size: number of entries in the feature table array.
116 * @probe: the function to call when a device is found. Returns 0 or -errno.
117 * @remove: the function to call when a device is removed.
118 * @config_changed: optional function to call when the device configuration
119 * changes; may be called in interrupt context.
120 */
121 struct virtio_driver {
122 struct device_driver driver;
123 const struct virtio_device_id *id_table;
124 const unsigned int *feature_table;
125 unsigned int feature_table_size;
126 int (*probe)(struct virtio_device *dev);
127 void (*scan)(struct virtio_device *dev);
128 void (*remove)(struct virtio_device *dev);
129 void (*config_changed)(struct virtio_device *dev);
130 #ifdef CONFIG_PM
131 int (*freeze)(struct virtio_device *dev);
132 int (*restore)(struct virtio_device *dev);
133 #endif
134 };
135
drv_to_virtio(struct device_driver * drv)136 static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
137 {
138 return container_of(drv, struct virtio_driver, driver);
139 }
140
141 int register_virtio_driver(struct virtio_driver *drv);
142 void unregister_virtio_driver(struct virtio_driver *drv);
143
144 /* module_virtio_driver() - Helper macro for drivers that don't do
145 * anything special in module init/exit. This eliminates a lot of
146 * boilerplate. Each module may only use this macro once, and
147 * calling it replaces module_init() and module_exit()
148 */
149 #define module_virtio_driver(__virtio_driver) \
150 module_driver(__virtio_driver, register_virtio_driver, \
151 unregister_virtio_driver)
152 #endif /* _LINUX_VIRTIO_H */
153