Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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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_inbuf_ctx(struct virtqueue *vq,
48 struct scatterlist sg[], unsigned int num,
49 void *data,
50 void *ctx,
51 gfp_t gfp);
52
53int virtqueue_add_sgs(struct virtqueue *vq,
54 struct scatterlist *sgs[],
55 unsigned int out_sgs,
56 unsigned int in_sgs,
57 void *data,
58 gfp_t gfp);
59
60bool virtqueue_kick(struct virtqueue *vq);
61
62bool virtqueue_kick_prepare(struct virtqueue *vq);
63
64bool virtqueue_notify(struct virtqueue *vq);
65
66void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
67
68void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
69 void **ctx);
70
71void virtqueue_disable_cb(struct virtqueue *vq);
72
73bool virtqueue_enable_cb(struct virtqueue *vq);
74
75unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
76
77bool virtqueue_poll(struct virtqueue *vq, unsigned);
78
79bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
80
81void *virtqueue_detach_unused_buf(struct virtqueue *vq);
82
83unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
84
85bool virtqueue_is_broken(struct virtqueue *vq);
86
87const struct vring *virtqueue_get_vring(struct virtqueue *vq);
88dma_addr_t virtqueue_get_desc_addr(struct virtqueue *vq);
89dma_addr_t virtqueue_get_avail_addr(struct virtqueue *vq);
90dma_addr_t virtqueue_get_used_addr(struct virtqueue *vq);
91
92/*
93 * Legacy accessors -- in almost all cases, these are the wrong functions
94 * to use.
95 */
96static inline void *virtqueue_get_desc(struct virtqueue *vq)
97{
98 return virtqueue_get_vring(vq)->desc;
99}
100static inline void *virtqueue_get_avail(struct virtqueue *vq)
101{
102 return virtqueue_get_vring(vq)->avail;
103}
104static inline void *virtqueue_get_used(struct virtqueue *vq)
105{
106 return virtqueue_get_vring(vq)->used;
107}
108
109/**
110 * virtio_device - representation of a device using virtio
111 * @index: unique position on the virtio bus
112 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
113 * @config_enabled: configuration change reporting enabled
114 * @config_change_pending: configuration change reported while disabled
115 * @config_lock: protects configuration change reporting
116 * @dev: underlying device.
117 * @id: the device type identification (used to match it with a driver).
118 * @config: the configuration ops for this device.
119 * @vringh_config: configuration ops for host vrings.
120 * @vqs: the list of virtqueues for this device.
121 * @features: the features supported by both driver and device.
122 * @priv: private pointer for the driver's use.
123 */
124struct virtio_device {
125 int index;
126 bool failed;
127 bool config_enabled;
128 bool config_change_pending;
129 spinlock_t config_lock;
130 struct device dev;
131 struct virtio_device_id id;
132 const struct virtio_config_ops *config;
133 const struct vringh_config_ops *vringh_config;
134 struct list_head vqs;
135 u64 features;
136 void *priv;
137};
138
139static inline struct virtio_device *dev_to_virtio(struct device *_dev)
140{
141 return container_of(_dev, struct virtio_device, dev);
142}
143
144void virtio_add_status(struct virtio_device *dev, unsigned int status);
145int register_virtio_device(struct virtio_device *dev);
146void unregister_virtio_device(struct virtio_device *dev);
147
148void virtio_break_device(struct virtio_device *dev);
149
150void virtio_config_changed(struct virtio_device *dev);
151void virtio_config_disable(struct virtio_device *dev);
152void virtio_config_enable(struct virtio_device *dev);
153int virtio_finalize_features(struct virtio_device *dev);
154#ifdef CONFIG_PM_SLEEP
155int virtio_device_freeze(struct virtio_device *dev);
156int virtio_device_restore(struct virtio_device *dev);
157#endif
158
159/**
160 * virtio_driver - operations for a virtio I/O driver
161 * @driver: underlying device driver (populate name and owner).
162 * @id_table: the ids serviced by this driver.
163 * @feature_table: an array of feature numbers supported by this driver.
164 * @feature_table_size: number of entries in the feature table array.
165 * @feature_table_legacy: same as feature_table but when working in legacy mode.
166 * @feature_table_size_legacy: number of entries in feature table legacy array.
167 * @probe: the function to call when a device is found. Returns 0 or -errno.
168 * @scan: optional function to call after successful probe; intended
169 * for virtio-scsi to invoke a scan.
170 * @remove: the function to call when a device is removed.
171 * @config_changed: optional function to call when the device configuration
172 * changes; may be called in interrupt context.
173 * @freeze: optional function to call during suspend/hibernation.
174 * @restore: optional function to call on resume.
175 */
176struct virtio_driver {
177 struct device_driver driver;
178 const struct virtio_device_id *id_table;
179 const unsigned int *feature_table;
180 unsigned int feature_table_size;
181 const unsigned int *feature_table_legacy;
182 unsigned int feature_table_size_legacy;
183 int (*validate)(struct virtio_device *dev);
184 int (*probe)(struct virtio_device *dev);
185 void (*scan)(struct virtio_device *dev);
186 void (*remove)(struct virtio_device *dev);
187 void (*config_changed)(struct virtio_device *dev);
188#ifdef CONFIG_PM
189 int (*freeze)(struct virtio_device *dev);
190 int (*restore)(struct virtio_device *dev);
191#endif
192};
193
194static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
195{
196 return container_of(drv, struct virtio_driver, driver);
197}
198
199int register_virtio_driver(struct virtio_driver *drv);
200void unregister_virtio_driver(struct virtio_driver *drv);
201
202/* module_virtio_driver() - Helper macro for drivers that don't do
203 * anything special in module init/exit. This eliminates a lot of
204 * boilerplate. Each module may only use this macro once, and
205 * calling it replaces module_init() and module_exit()
206 */
207#define module_virtio_driver(__virtio_driver) \
208 module_driver(__virtio_driver, register_virtio_driver, \
209 unregister_virtio_driver)
210#endif /* _LINUX_VIRTIO_H */