Linux kernel mirror (for testing)
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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _LINUX_VIRTIO_H
3#define _LINUX_VIRTIO_H
4/* Everything a virtio driver needs to work with any particular virtio
5 * implementation. */
6#include <linux/types.h>
7#include <linux/scatterlist.h>
8#include <linux/spinlock.h>
9#include <linux/device.h>
10#include <linux/mod_devicetable.h>
11#include <linux/gfp.h>
12
13/**
14 * struct 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 * @num_max: the maximum number of elements supported by the device.
23 * @reset: vq is in reset state or not.
24 *
25 * A note on @num_free: with indirect buffers, each buffer needs one
26 * element in the queue, otherwise a buffer will need one element per
27 * sg element.
28 */
29struct virtqueue {
30 struct list_head list;
31 void (*callback)(struct virtqueue *vq);
32 const char *name;
33 struct virtio_device *vdev;
34 unsigned int index;
35 unsigned int num_free;
36 unsigned int num_max;
37 bool reset;
38 void *priv;
39};
40
41int virtqueue_add_outbuf(struct virtqueue *vq,
42 struct scatterlist sg[], unsigned int num,
43 void *data,
44 gfp_t gfp);
45
46int virtqueue_add_inbuf(struct virtqueue *vq,
47 struct scatterlist sg[], unsigned int num,
48 void *data,
49 gfp_t gfp);
50
51int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
52 struct scatterlist sg[], unsigned int num,
53 void *data,
54 void *ctx,
55 gfp_t gfp);
56
57int virtqueue_add_sgs(struct virtqueue *vq,
58 struct scatterlist *sgs[],
59 unsigned int out_sgs,
60 unsigned int in_sgs,
61 void *data,
62 gfp_t gfp);
63
64bool virtqueue_kick(struct virtqueue *vq);
65
66bool virtqueue_kick_prepare(struct virtqueue *vq);
67
68bool virtqueue_notify(struct virtqueue *vq);
69
70void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
71
72void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
73 void **ctx);
74
75void virtqueue_disable_cb(struct virtqueue *vq);
76
77bool virtqueue_enable_cb(struct virtqueue *vq);
78
79unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
80
81bool virtqueue_poll(struct virtqueue *vq, unsigned);
82
83bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
84
85void *virtqueue_detach_unused_buf(struct virtqueue *vq);
86
87unsigned int virtqueue_get_vring_size(const struct virtqueue *vq);
88
89bool virtqueue_is_broken(const struct virtqueue *vq);
90
91const struct vring *virtqueue_get_vring(const struct virtqueue *vq);
92dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq);
93dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq);
94dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq);
95
96int virtqueue_resize(struct virtqueue *vq, u32 num,
97 void (*recycle)(struct virtqueue *vq, void *buf));
98
99/**
100 * struct virtio_device - representation of a device using virtio
101 * @index: unique position on the virtio bus
102 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
103 * @config_enabled: configuration change reporting enabled
104 * @config_change_pending: configuration change reported while disabled
105 * @config_lock: protects configuration change reporting
106 * @vqs_list_lock: protects @vqs.
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 spinlock_t vqs_list_lock;
122 struct device dev;
123 struct virtio_device_id id;
124 const struct virtio_config_ops *config;
125 const struct vringh_config_ops *vringh_config;
126 struct list_head vqs;
127 u64 features;
128 void *priv;
129};
130
131#define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev)
132
133void virtio_add_status(struct virtio_device *dev, unsigned int status);
134int register_virtio_device(struct virtio_device *dev);
135void unregister_virtio_device(struct virtio_device *dev);
136bool is_virtio_device(struct device *dev);
137
138void virtio_break_device(struct virtio_device *dev);
139void __virtio_unbreak_device(struct virtio_device *dev);
140
141void __virtqueue_break(struct virtqueue *_vq);
142void __virtqueue_unbreak(struct virtqueue *_vq);
143
144void virtio_config_changed(struct virtio_device *dev);
145#ifdef CONFIG_PM_SLEEP
146int virtio_device_freeze(struct virtio_device *dev);
147int virtio_device_restore(struct virtio_device *dev);
148#endif
149void virtio_reset_device(struct virtio_device *dev);
150
151size_t virtio_max_dma_size(const struct virtio_device *vdev);
152
153#define virtio_device_for_each_vq(vdev, vq) \
154 list_for_each_entry(vq, &vdev->vqs, list)
155
156/**
157 * struct virtio_driver - operations for a virtio I/O driver
158 * @driver: underlying device driver (populate name and owner).
159 * @id_table: the ids serviced by this driver.
160 * @feature_table: an array of feature numbers supported by this driver.
161 * @feature_table_size: number of entries in the feature table array.
162 * @feature_table_legacy: same as feature_table but when working in legacy mode.
163 * @feature_table_size_legacy: number of entries in feature table legacy array.
164 * @validate: the function to call to validate features and config space.
165 * Returns 0 or -errno.
166 * @probe: the function to call when a device is found. Returns 0 or -errno.
167 * @scan: optional function to call after successful probe; intended
168 * for virtio-scsi to invoke a scan.
169 * @remove: the function to call when a device is removed.
170 * @config_changed: optional function to call when the device configuration
171 * changes; may be called in interrupt context.
172 * @freeze: optional function to call during suspend/hibernation.
173 * @restore: optional function to call on resume.
174 */
175struct virtio_driver {
176 struct device_driver driver;
177 const struct virtio_device_id *id_table;
178 const unsigned int *feature_table;
179 unsigned int feature_table_size;
180 const unsigned int *feature_table_legacy;
181 unsigned int feature_table_size_legacy;
182 int (*validate)(struct virtio_device *dev);
183 int (*probe)(struct virtio_device *dev);
184 void (*scan)(struct virtio_device *dev);
185 void (*remove)(struct virtio_device *dev);
186 void (*config_changed)(struct virtio_device *dev);
187#ifdef CONFIG_PM
188 int (*freeze)(struct virtio_device *dev);
189 int (*restore)(struct virtio_device *dev);
190#endif
191};
192
193static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
194{
195 return container_of(drv, struct virtio_driver, driver);
196}
197
198int register_virtio_driver(struct virtio_driver *drv);
199void unregister_virtio_driver(struct virtio_driver *drv);
200
201/* module_virtio_driver() - Helper macro for drivers that don't do
202 * anything special in module init/exit. This eliminates a lot of
203 * boilerplate. Each module may only use this macro once, and
204 * calling it replaces module_init() and module_exit()
205 */
206#define module_virtio_driver(__virtio_driver) \
207 module_driver(__virtio_driver, register_virtio_driver, \
208 unregister_virtio_driver)
209#endif /* _LINUX_VIRTIO_H */