1 #ifndef _LINUX_VIRTIO_H
2 #define _LINUX_VIRTIO_H
3 /* Everything a virtio driver needs to work with any particular virtio
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>
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.
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
28 struct list_head list;
29 void (*callback)(struct virtqueue *vq);
31 struct virtio_device *vdev;
33 unsigned int num_free;
37 int virtqueue_add_outbuf(struct virtqueue *vq,
38 struct scatterlist sg[], unsigned int num,
42 int virtqueue_add_inbuf(struct virtqueue *vq,
43 struct scatterlist sg[], unsigned int num,
47 int virtqueue_add_sgs(struct virtqueue *vq,
48 struct scatterlist *sgs[],
54 bool virtqueue_kick(struct virtqueue *vq);
56 bool virtqueue_kick_prepare(struct virtqueue *vq);
58 bool virtqueue_notify(struct virtqueue *vq);
60 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
62 void virtqueue_disable_cb(struct virtqueue *vq);
64 bool virtqueue_enable_cb(struct virtqueue *vq);
66 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
68 bool virtqueue_poll(struct virtqueue *vq, unsigned);
70 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
72 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
74 unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
76 bool virtqueue_is_broken(struct virtqueue *vq);
79 * virtio_device - representation of a device using virtio
80 * @index: unique position on the virtio bus
81 * @failed: saved value for CONFIG_S_FAILED bit (for restore)
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.
90 struct virtio_device {
94 struct virtio_device_id id;
95 const struct virtio_config_ops *config;
96 const struct vringh_config_ops *vringh_config;
98 /* Note that this is a Linux set_bit-style bitmap. */
99 unsigned long features[1];
103 static inline struct virtio_device *dev_to_virtio(struct device *_dev)
105 return container_of(_dev, struct virtio_device, dev);
108 int register_virtio_device(struct virtio_device *dev);
109 void unregister_virtio_device(struct virtio_device *dev);
111 void virtio_break_device(struct virtio_device *dev);
113 void virtio_config_changed(struct virtio_device *dev);
114 #ifdef CONFIG_PM_SLEEP
115 int virtio_device_freeze(struct virtio_device *dev);
116 int virtio_device_restore(struct virtio_device *dev);
120 * virtio_driver - operations for a virtio I/O driver
121 * @driver: underlying device driver (populate name and owner).
122 * @id_table: the ids serviced by this driver.
123 * @feature_table: an array of feature numbers supported by this driver.
124 * @feature_table_size: number of entries in the feature table array.
125 * @probe: the function to call when a device is found. Returns 0 or -errno.
126 * @remove: the function to call when a device is removed.
127 * @config_changed: optional function to call when the device configuration
128 * changes; may be called in interrupt context.
130 struct virtio_driver {
131 struct device_driver driver;
132 const struct virtio_device_id *id_table;
133 const unsigned int *feature_table;
134 unsigned int feature_table_size;
135 int (*probe)(struct virtio_device *dev);
136 void (*scan)(struct virtio_device *dev);
137 void (*remove)(struct virtio_device *dev);
138 void (*config_changed)(struct virtio_device *dev);
140 int (*freeze)(struct virtio_device *dev);
141 int (*restore)(struct virtio_device *dev);
145 static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
147 return container_of(drv, struct virtio_driver, driver);
150 int register_virtio_driver(struct virtio_driver *drv);
151 void unregister_virtio_driver(struct virtio_driver *drv);
153 /* module_virtio_driver() - Helper macro for drivers that don't do
154 * anything special in module init/exit. This eliminates a lot of
155 * boilerplate. Each module may only use this macro once, and
156 * calling it replaces module_init() and module_exit()
158 #define module_virtio_driver(__virtio_driver) \
159 module_driver(__virtio_driver, register_virtio_driver, \
160 unregister_virtio_driver)
161 #endif /* _LINUX_VIRTIO_H */