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#include <linux/dma-mapping.h>
13#include <linux/completion.h>
14
15/**
16 * struct virtqueue - a queue to register buffers for sending or receiving.
17 * @list: the chain of virtqueues for this device
18 * @callback: the function to call when buffers are consumed (can be NULL).
19 * @name: the name of this virtqueue (mainly for debugging)
20 * @vdev: the virtio device this queue was created for.
21 * @priv: a pointer for the virtqueue implementation to use.
22 * @index: the zero-based ordinal number for this queue.
23 * @num_free: number of elements we expect to be able to fit.
24 * @num_max: the maximum number of elements supported by the device.
25 * @reset: vq is in reset state or not.
26 *
27 * A note on @num_free: with indirect buffers, each buffer needs one
28 * element in the queue, otherwise a buffer will need one element per
29 * sg element.
30 */
31struct virtqueue {
32 struct list_head list;
33 void (*callback)(struct virtqueue *vq);
34 const char *name;
35 struct virtio_device *vdev;
36 unsigned int index;
37 unsigned int num_free;
38 unsigned int num_max;
39 bool reset;
40 void *priv;
41};
42
43int virtqueue_add_outbuf(struct virtqueue *vq,
44 struct scatterlist sg[], unsigned int num,
45 void *data,
46 gfp_t gfp);
47
48int virtqueue_add_inbuf(struct virtqueue *vq,
49 struct scatterlist sg[], unsigned int num,
50 void *data,
51 gfp_t gfp);
52
53int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
54 struct scatterlist sg[], unsigned int num,
55 void *data,
56 void *ctx,
57 gfp_t gfp);
58
59int virtqueue_add_sgs(struct virtqueue *vq,
60 struct scatterlist *sgs[],
61 unsigned int out_sgs,
62 unsigned int in_sgs,
63 void *data,
64 gfp_t gfp);
65
66struct device *virtqueue_dma_dev(struct virtqueue *vq);
67
68bool virtqueue_kick(struct virtqueue *vq);
69
70bool virtqueue_kick_prepare(struct virtqueue *vq);
71
72bool virtqueue_notify(struct virtqueue *vq);
73
74void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
75
76void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
77 void **ctx);
78
79void virtqueue_disable_cb(struct virtqueue *vq);
80
81bool virtqueue_enable_cb(struct virtqueue *vq);
82
83unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
84
85int virtqueue_set_dma_premapped(struct virtqueue *_vq);
86
87bool virtqueue_poll(struct virtqueue *vq, unsigned);
88
89bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
90
91void *virtqueue_detach_unused_buf(struct virtqueue *vq);
92
93unsigned int virtqueue_get_vring_size(const struct virtqueue *vq);
94
95bool virtqueue_is_broken(const struct virtqueue *vq);
96
97const struct vring *virtqueue_get_vring(const struct virtqueue *vq);
98dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq);
99dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq);
100dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq);
101
102int virtqueue_resize(struct virtqueue *vq, u32 num,
103 void (*recycle)(struct virtqueue *vq, void *buf));
104int virtqueue_reset(struct virtqueue *vq,
105 void (*recycle)(struct virtqueue *vq, void *buf));
106
107struct virtio_admin_cmd {
108 __le16 opcode;
109 __le16 group_type;
110 __le64 group_member_id;
111 struct scatterlist *data_sg;
112 struct scatterlist *result_sg;
113 struct completion completion;
114 int ret;
115};
116
117/**
118 * struct virtio_device - representation of a device using virtio
119 * @index: unique position on the virtio bus
120 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
121 * @config_enabled: configuration change reporting enabled
122 * @config_change_pending: configuration change reported while disabled
123 * @config_lock: protects configuration change reporting
124 * @vqs_list_lock: protects @vqs.
125 * @dev: underlying device.
126 * @id: the device type identification (used to match it with a driver).
127 * @config: the configuration ops for this device.
128 * @vringh_config: configuration ops for host vrings.
129 * @vqs: the list of virtqueues for this device.
130 * @features: the features supported by both driver and device.
131 * @priv: private pointer for the driver's use.
132 * @debugfs_dir: debugfs directory entry.
133 * @debugfs_filter_features: features to be filtered set by debugfs.
134 */
135struct virtio_device {
136 int index;
137 bool failed;
138 bool config_enabled;
139 bool config_change_pending;
140 spinlock_t config_lock;
141 spinlock_t vqs_list_lock;
142 struct device dev;
143 struct virtio_device_id id;
144 const struct virtio_config_ops *config;
145 const struct vringh_config_ops *vringh_config;
146 struct list_head vqs;
147 u64 features;
148 void *priv;
149#ifdef CONFIG_VIRTIO_DEBUG
150 struct dentry *debugfs_dir;
151 u64 debugfs_filter_features;
152#endif
153};
154
155#define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev)
156
157void virtio_add_status(struct virtio_device *dev, unsigned int status);
158int register_virtio_device(struct virtio_device *dev);
159void unregister_virtio_device(struct virtio_device *dev);
160bool is_virtio_device(struct device *dev);
161
162void virtio_break_device(struct virtio_device *dev);
163void __virtio_unbreak_device(struct virtio_device *dev);
164
165void __virtqueue_break(struct virtqueue *_vq);
166void __virtqueue_unbreak(struct virtqueue *_vq);
167
168void virtio_config_changed(struct virtio_device *dev);
169#ifdef CONFIG_PM_SLEEP
170int virtio_device_freeze(struct virtio_device *dev);
171int virtio_device_restore(struct virtio_device *dev);
172#endif
173void virtio_reset_device(struct virtio_device *dev);
174
175size_t virtio_max_dma_size(const struct virtio_device *vdev);
176
177#define virtio_device_for_each_vq(vdev, vq) \
178 list_for_each_entry(vq, &vdev->vqs, list)
179
180/**
181 * struct virtio_driver - operations for a virtio I/O driver
182 * @driver: underlying device driver (populate name).
183 * @id_table: the ids serviced by this driver.
184 * @feature_table: an array of feature numbers supported by this driver.
185 * @feature_table_size: number of entries in the feature table array.
186 * @feature_table_legacy: same as feature_table but when working in legacy mode.
187 * @feature_table_size_legacy: number of entries in feature table legacy array.
188 * @validate: the function to call to validate features and config space.
189 * Returns 0 or -errno.
190 * @probe: the function to call when a device is found. Returns 0 or -errno.
191 * @scan: optional function to call after successful probe; intended
192 * for virtio-scsi to invoke a scan.
193 * @remove: the function to call when a device is removed.
194 * @config_changed: optional function to call when the device configuration
195 * changes; may be called in interrupt context.
196 * @freeze: optional function to call during suspend/hibernation.
197 * @restore: optional function to call on resume.
198 */
199struct virtio_driver {
200 struct device_driver driver;
201 const struct virtio_device_id *id_table;
202 const unsigned int *feature_table;
203 unsigned int feature_table_size;
204 const unsigned int *feature_table_legacy;
205 unsigned int feature_table_size_legacy;
206 int (*validate)(struct virtio_device *dev);
207 int (*probe)(struct virtio_device *dev);
208 void (*scan)(struct virtio_device *dev);
209 void (*remove)(struct virtio_device *dev);
210 void (*config_changed)(struct virtio_device *dev);
211 int (*freeze)(struct virtio_device *dev);
212 int (*restore)(struct virtio_device *dev);
213};
214
215#define drv_to_virtio(__drv) container_of_const(__drv, struct virtio_driver, driver)
216
217/* use a macro to avoid include chaining to get THIS_MODULE */
218#define register_virtio_driver(drv) \
219 __register_virtio_driver(drv, THIS_MODULE)
220int __register_virtio_driver(struct virtio_driver *drv, struct module *owner);
221void unregister_virtio_driver(struct virtio_driver *drv);
222
223/* module_virtio_driver() - Helper macro for drivers that don't do
224 * anything special in module init/exit. This eliminates a lot of
225 * boilerplate. Each module may only use this macro once, and
226 * calling it replaces module_init() and module_exit()
227 */
228#define module_virtio_driver(__virtio_driver) \
229 module_driver(__virtio_driver, register_virtio_driver, \
230 unregister_virtio_driver)
231
232dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr, size_t size,
233 enum dma_data_direction dir, unsigned long attrs);
234void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr,
235 size_t size, enum dma_data_direction dir,
236 unsigned long attrs);
237int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr);
238
239bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr);
240void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, dma_addr_t addr,
241 unsigned long offset, size_t size,
242 enum dma_data_direction dir);
243void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr,
244 unsigned long offset, size_t size,
245 enum dma_data_direction dir);
246
247#ifdef CONFIG_VIRTIO_DEBUG
248void virtio_debug_device_init(struct virtio_device *dev);
249void virtio_debug_device_exit(struct virtio_device *dev);
250void virtio_debug_device_filter_features(struct virtio_device *dev);
251void virtio_debug_init(void);
252void virtio_debug_exit(void);
253#else
254static inline void virtio_debug_device_init(struct virtio_device *dev)
255{
256}
257
258static inline void virtio_debug_device_exit(struct virtio_device *dev)
259{
260}
261
262static inline void virtio_debug_device_filter_features(struct virtio_device *dev)
263{
264}
265
266static inline void virtio_debug_init(void)
267{
268}
269
270static inline void virtio_debug_exit(void)
271{
272}
273#endif
274
275#endif /* _LINUX_VIRTIO_H */