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_outbuf(struct virtqueue *vq,
38 struct scatterlist sg[], unsigned int num,
39 void *data,
40 gfp_t gfp);
41
42 int virtqueue_add_inbuf(struct virtqueue *vq,
43 struct scatterlist sg[], unsigned int num,
44 void *data,
45 gfp_t gfp);
46
47 int virtqueue_add_sgs(struct virtqueue *vq,
48 struct scatterlist *sgs[],
49 unsigned int out_sgs,
50 unsigned int in_sgs,
51 void *data,
52 gfp_t gfp);
53
54 bool virtqueue_kick(struct virtqueue *vq);
55
56 bool virtqueue_kick_prepare(struct virtqueue *vq);
57
58 bool virtqueue_notify(struct virtqueue *vq);
59
60 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
61
62 void virtqueue_disable_cb(struct virtqueue *vq);
63
64 bool virtqueue_enable_cb(struct virtqueue *vq);
65
66 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
67
68 bool virtqueue_poll(struct virtqueue *vq, unsigned);
69
70 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
71
72 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
73
74 unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
75
76 bool virtqueue_is_broken(struct virtqueue *vq);
77
78 void *virtqueue_get_avail(struct virtqueue *vq);
79 void *virtqueue_get_used(struct virtqueue *vq);
80
81 /**
82 * virtio_device - representation of a device using virtio
83 * @index: unique position on the virtio bus
84 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
85 * @config_enabled: configuration change reporting enabled
86 * @config_change_pending: configuration change reported while disabled
87 * @config_lock: protects configuration change reporting
88 * @dev: underlying device.
89 * @id: the device type identification (used to match it with a driver).
90 * @config: the configuration ops for this device.
91 * @vringh_config: configuration ops for host vrings.
92 * @vqs: the list of virtqueues for this device.
93 * @features: the features supported by both driver and device.
94 * @priv: private pointer for the driver's use.
95 */
96 struct virtio_device {
97 int index;
98 bool failed;
99 bool config_enabled;
100 bool config_change_pending;
101 spinlock_t config_lock;
102 struct device dev;
103 struct virtio_device_id id;
104 const struct virtio_config_ops *config;
105 const struct vringh_config_ops *vringh_config;
106 struct list_head vqs;
107 u64 features;
108 void *priv;
109 };
110
dev_to_virtio(struct device * _dev)111 static inline struct virtio_device *dev_to_virtio(struct device *_dev)
112 {
113 return container_of(_dev, struct virtio_device, dev);
114 }
115
116 int register_virtio_device(struct virtio_device *dev);
117 void unregister_virtio_device(struct virtio_device *dev);
118
119 void virtio_break_device(struct virtio_device *dev);
120
121 void virtio_config_changed(struct virtio_device *dev);
122 #ifdef CONFIG_PM_SLEEP
123 int virtio_device_freeze(struct virtio_device *dev);
124 int virtio_device_restore(struct virtio_device *dev);
125 #endif
126
127 /**
128 * virtio_driver - operations for a virtio I/O driver
129 * @driver: underlying device driver (populate name and owner).
130 * @id_table: the ids serviced by this driver.
131 * @feature_table: an array of feature numbers supported by this driver.
132 * @feature_table_size: number of entries in the feature table array.
133 * @feature_table_legacy: same as feature_table but when working in legacy mode.
134 * @feature_table_size_legacy: number of entries in feature table legacy array.
135 * @probe: the function to call when a device is found. Returns 0 or -errno.
136 * @remove: the function to call when a device is removed.
137 * @config_changed: optional function to call when the device configuration
138 * changes; may be called in interrupt context.
139 */
140 struct virtio_driver {
141 struct device_driver driver;
142 const struct virtio_device_id *id_table;
143 const unsigned int *feature_table;
144 unsigned int feature_table_size;
145 const unsigned int *feature_table_legacy;
146 unsigned int feature_table_size_legacy;
147 int (*probe)(struct virtio_device *dev);
148 void (*scan)(struct virtio_device *dev);
149 void (*remove)(struct virtio_device *dev);
150 void (*config_changed)(struct virtio_device *dev);
151 #ifdef CONFIG_PM
152 int (*freeze)(struct virtio_device *dev);
153 int (*restore)(struct virtio_device *dev);
154 #endif
155 };
156
drv_to_virtio(struct device_driver * drv)157 static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
158 {
159 return container_of(drv, struct virtio_driver, driver);
160 }
161
162 int register_virtio_driver(struct virtio_driver *drv);
163 void unregister_virtio_driver(struct virtio_driver *drv);
164
165 /* module_virtio_driver() - Helper macro for drivers that don't do
166 * anything special in module init/exit. This eliminates a lot of
167 * boilerplate. Each module may only use this macro once, and
168 * calling it replaces module_init() and module_exit()
169 */
170 #define module_virtio_driver(__virtio_driver) \
171 module_driver(__virtio_driver, register_virtio_driver, \
172 unregister_virtio_driver)
173 #endif /* _LINUX_VIRTIO_H */
174