Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
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 */
27struct 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
37int virtqueue_add_outbuf(struct virtqueue *vq,
38 struct scatterlist sg[], unsigned int num,
39 void *data,
40 gfp_t gfp);
41
42int virtqueue_add_inbuf(struct virtqueue *vq,
43 struct scatterlist sg[], unsigned int num,
44 void *data,
45 gfp_t gfp);
46
47int 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
54bool virtqueue_kick(struct virtqueue *vq);
55
56bool virtqueue_kick_prepare(struct virtqueue *vq);
57
58bool virtqueue_notify(struct virtqueue *vq);
59
60void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
61
62void virtqueue_disable_cb(struct virtqueue *vq);
63
64bool virtqueue_enable_cb(struct virtqueue *vq);
65
66unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
67
68bool virtqueue_poll(struct virtqueue *vq, unsigned);
69
70bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
71
72void *virtqueue_detach_unused_buf(struct virtqueue *vq);
73
74unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
75
76bool virtqueue_is_broken(struct virtqueue *vq);
77
78const struct vring *virtqueue_get_vring(struct virtqueue *vq);
79dma_addr_t virtqueue_get_desc_addr(struct virtqueue *vq);
80dma_addr_t virtqueue_get_avail_addr(struct virtqueue *vq);
81dma_addr_t virtqueue_get_used_addr(struct virtqueue *vq);
82
83/*
84 * Legacy accessors -- in almost all cases, these are the wrong functions
85 * to use.
86 */
87static inline void *virtqueue_get_desc(struct virtqueue *vq)
88{
89 return virtqueue_get_vring(vq)->desc;
90}
91static inline void *virtqueue_get_avail(struct virtqueue *vq)
92{
93 return virtqueue_get_vring(vq)->avail;
94}
95static inline void *virtqueue_get_used(struct virtqueue *vq)
96{
97 return virtqueue_get_vring(vq)->used;
98}
99
100/**
101 * virtio_device - representation of a device using virtio
102 * @index: unique position on the virtio bus
103 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
104 * @config_enabled: configuration change reporting enabled
105 * @config_change_pending: configuration change reported while disabled
106 * @config_lock: protects configuration change reporting
107 * @dev: underlying device.
108 * @id: the device type identification (used to match it with a driver).
109 * @config: the configuration ops for this device.
110 * @vringh_config: configuration ops for host vrings.
111 * @vqs: the list of virtqueues for this device.
112 * @features: the features supported by both driver and device.
113 * @priv: private pointer for the driver's use.
114 */
115struct virtio_device {
116 int index;
117 bool failed;
118 bool config_enabled;
119 bool config_change_pending;
120 spinlock_t config_lock;
121 struct device dev;
122 struct virtio_device_id id;
123 const struct virtio_config_ops *config;
124 const struct vringh_config_ops *vringh_config;
125 struct list_head vqs;
126 u64 features;
127 void *priv;
128};
129
130static inline struct virtio_device *dev_to_virtio(struct device *_dev)
131{
132 return container_of(_dev, struct virtio_device, dev);
133}
134
135int register_virtio_device(struct virtio_device *dev);
136void unregister_virtio_device(struct virtio_device *dev);
137
138void virtio_break_device(struct virtio_device *dev);
139
140void virtio_config_changed(struct virtio_device *dev);
141#ifdef CONFIG_PM_SLEEP
142int virtio_device_freeze(struct virtio_device *dev);
143int virtio_device_restore(struct virtio_device *dev);
144#endif
145
146/**
147 * virtio_driver - operations for a virtio I/O driver
148 * @driver: underlying device driver (populate name and owner).
149 * @id_table: the ids serviced by this driver.
150 * @feature_table: an array of feature numbers supported by this driver.
151 * @feature_table_size: number of entries in the feature table array.
152 * @feature_table_legacy: same as feature_table but when working in legacy mode.
153 * @feature_table_size_legacy: number of entries in feature table legacy array.
154 * @probe: the function to call when a device is found. Returns 0 or -errno.
155 * @remove: the function to call when a device is removed.
156 * @config_changed: optional function to call when the device configuration
157 * changes; may be called in interrupt context.
158 */
159struct virtio_driver {
160 struct device_driver driver;
161 const struct virtio_device_id *id_table;
162 const unsigned int *feature_table;
163 unsigned int feature_table_size;
164 const unsigned int *feature_table_legacy;
165 unsigned int feature_table_size_legacy;
166 int (*probe)(struct virtio_device *dev);
167 void (*scan)(struct virtio_device *dev);
168 void (*remove)(struct virtio_device *dev);
169 void (*config_changed)(struct virtio_device *dev);
170#ifdef CONFIG_PM
171 int (*freeze)(struct virtio_device *dev);
172 int (*restore)(struct virtio_device *dev);
173#endif
174};
175
176static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
177{
178 return container_of(drv, struct virtio_driver, driver);
179}
180
181int register_virtio_driver(struct virtio_driver *drv);
182void unregister_virtio_driver(struct virtio_driver *drv);
183
184/* module_virtio_driver() - Helper macro for drivers that don't do
185 * anything special in module init/exit. This eliminates a lot of
186 * boilerplate. Each module may only use this macro once, and
187 * calling it replaces module_init() and module_exit()
188 */
189#define module_virtio_driver(__virtio_driver) \
190 module_driver(__virtio_driver, register_virtio_driver, \
191 unregister_virtio_driver)
192#endif /* _LINUX_VIRTIO_H */