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_inbuf_premapped(struct virtqueue *vq,
60 struct scatterlist *sg, unsigned int num,
61 void *data,
62 void *ctx,
63 gfp_t gfp);
64
65int virtqueue_add_outbuf_premapped(struct virtqueue *vq,
66 struct scatterlist *sg, unsigned int num,
67 void *data,
68 gfp_t gfp);
69
70int virtqueue_add_sgs(struct virtqueue *vq,
71 struct scatterlist *sgs[],
72 unsigned int out_sgs,
73 unsigned int in_sgs,
74 void *data,
75 gfp_t gfp);
76
77struct device *virtqueue_dma_dev(struct virtqueue *vq);
78
79bool virtqueue_kick(struct virtqueue *vq);
80
81bool virtqueue_kick_prepare(struct virtqueue *vq);
82
83bool virtqueue_notify(struct virtqueue *vq);
84
85void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
86
87void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
88 void **ctx);
89
90void virtqueue_disable_cb(struct virtqueue *vq);
91
92bool virtqueue_enable_cb(struct virtqueue *vq);
93
94unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
95
96bool virtqueue_poll(struct virtqueue *vq, unsigned);
97
98bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
99
100void *virtqueue_detach_unused_buf(struct virtqueue *vq);
101
102unsigned int virtqueue_get_vring_size(const struct virtqueue *vq);
103
104bool virtqueue_is_broken(const struct virtqueue *vq);
105
106const struct vring *virtqueue_get_vring(const struct virtqueue *vq);
107dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq);
108dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq);
109dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq);
110
111int virtqueue_resize(struct virtqueue *vq, u32 num,
112 void (*recycle)(struct virtqueue *vq, void *buf),
113 void (*recycle_done)(struct virtqueue *vq));
114int virtqueue_reset(struct virtqueue *vq,
115 void (*recycle)(struct virtqueue *vq, void *buf),
116 void (*recycle_done)(struct virtqueue *vq));
117
118struct virtio_admin_cmd {
119 __le16 opcode;
120 __le16 group_type;
121 __le64 group_member_id;
122 struct scatterlist *data_sg;
123 struct scatterlist *result_sg;
124 struct completion completion;
125 u32 result_sg_size;
126 int ret;
127};
128
129/**
130 * struct virtio_device - representation of a device using virtio
131 * @index: unique position on the virtio bus
132 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
133 * @config_core_enabled: configuration change reporting enabled by core
134 * @config_driver_disabled: configuration change reporting disabled by
135 * a driver
136 * @config_change_pending: configuration change reported while disabled
137 * @config_lock: protects configuration change reporting
138 * @vqs_list_lock: protects @vqs.
139 * @dev: underlying device.
140 * @id: the device type identification (used to match it with a driver).
141 * @config: the configuration ops for this device.
142 * @vringh_config: configuration ops for host vrings.
143 * @vqs: the list of virtqueues for this device.
144 * @features: the features supported by both driver and device.
145 * @priv: private pointer for the driver's use.
146 * @debugfs_dir: debugfs directory entry.
147 * @debugfs_filter_features: features to be filtered set by debugfs.
148 */
149struct virtio_device {
150 int index;
151 bool failed;
152 bool config_core_enabled;
153 bool config_driver_disabled;
154 bool config_change_pending;
155 spinlock_t config_lock;
156 spinlock_t vqs_list_lock;
157 struct device dev;
158 struct virtio_device_id id;
159 const struct virtio_config_ops *config;
160 const struct vringh_config_ops *vringh_config;
161 struct list_head vqs;
162 u64 features;
163 void *priv;
164#ifdef CONFIG_VIRTIO_DEBUG
165 struct dentry *debugfs_dir;
166 u64 debugfs_filter_features;
167#endif
168};
169
170#define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev)
171
172void virtio_add_status(struct virtio_device *dev, unsigned int status);
173int register_virtio_device(struct virtio_device *dev);
174void unregister_virtio_device(struct virtio_device *dev);
175bool is_virtio_device(struct device *dev);
176
177void virtio_break_device(struct virtio_device *dev);
178void __virtio_unbreak_device(struct virtio_device *dev);
179
180void __virtqueue_break(struct virtqueue *_vq);
181void __virtqueue_unbreak(struct virtqueue *_vq);
182
183void virtio_config_changed(struct virtio_device *dev);
184
185void virtio_config_driver_disable(struct virtio_device *dev);
186void virtio_config_driver_enable(struct virtio_device *dev);
187
188#ifdef CONFIG_PM_SLEEP
189int virtio_device_freeze(struct virtio_device *dev);
190int virtio_device_restore(struct virtio_device *dev);
191#endif
192void virtio_reset_device(struct virtio_device *dev);
193int virtio_device_reset_prepare(struct virtio_device *dev);
194int virtio_device_reset_done(struct virtio_device *dev);
195
196size_t virtio_max_dma_size(const struct virtio_device *vdev);
197
198#define virtio_device_for_each_vq(vdev, vq) \
199 list_for_each_entry(vq, &vdev->vqs, list)
200
201/**
202 * struct virtio_driver - operations for a virtio I/O driver
203 * @driver: underlying device driver (populate name).
204 * @id_table: the ids serviced by this driver.
205 * @feature_table: an array of feature numbers supported by this driver.
206 * @feature_table_size: number of entries in the feature table array.
207 * @feature_table_legacy: same as feature_table but when working in legacy mode.
208 * @feature_table_size_legacy: number of entries in feature table legacy array.
209 * @validate: the function to call to validate features and config space.
210 * Returns 0 or -errno.
211 * @probe: the function to call when a device is found. Returns 0 or -errno.
212 * @scan: optional function to call after successful probe; intended
213 * for virtio-scsi to invoke a scan.
214 * @remove: the function to call when a device is removed.
215 * @config_changed: optional function to call when the device configuration
216 * changes; may be called in interrupt context.
217 * @freeze: optional function to call during suspend/hibernation.
218 * @restore: optional function to call on resume.
219 * @reset_prepare: optional function to call when a transport specific reset
220 * occurs.
221 * @reset_done: optional function to call after transport specific reset
222 * operation has finished.
223 * @shutdown: synchronize with the device on shutdown. If provided, replaces
224 * the virtio core implementation.
225 */
226struct virtio_driver {
227 struct device_driver driver;
228 const struct virtio_device_id *id_table;
229 const unsigned int *feature_table;
230 unsigned int feature_table_size;
231 const unsigned int *feature_table_legacy;
232 unsigned int feature_table_size_legacy;
233 int (*validate)(struct virtio_device *dev);
234 int (*probe)(struct virtio_device *dev);
235 void (*scan)(struct virtio_device *dev);
236 void (*remove)(struct virtio_device *dev);
237 void (*config_changed)(struct virtio_device *dev);
238 int (*freeze)(struct virtio_device *dev);
239 int (*restore)(struct virtio_device *dev);
240 int (*reset_prepare)(struct virtio_device *dev);
241 int (*reset_done)(struct virtio_device *dev);
242 void (*shutdown)(struct virtio_device *dev);
243};
244
245#define drv_to_virtio(__drv) container_of_const(__drv, struct virtio_driver, driver)
246
247/* use a macro to avoid include chaining to get THIS_MODULE */
248#define register_virtio_driver(drv) \
249 __register_virtio_driver(drv, THIS_MODULE)
250int __register_virtio_driver(struct virtio_driver *drv, struct module *owner);
251void unregister_virtio_driver(struct virtio_driver *drv);
252
253/* module_virtio_driver() - Helper macro for drivers that don't do
254 * anything special in module init/exit. This eliminates a lot of
255 * boilerplate. Each module may only use this macro once, and
256 * calling it replaces module_init() and module_exit()
257 */
258#define module_virtio_driver(__virtio_driver) \
259 module_driver(__virtio_driver, register_virtio_driver, \
260 unregister_virtio_driver)
261
262dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr, size_t size,
263 enum dma_data_direction dir, unsigned long attrs);
264void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr,
265 size_t size, enum dma_data_direction dir,
266 unsigned long attrs);
267int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr);
268
269bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr);
270void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, dma_addr_t addr,
271 unsigned long offset, size_t size,
272 enum dma_data_direction dir);
273void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr,
274 unsigned long offset, size_t size,
275 enum dma_data_direction dir);
276
277#ifdef CONFIG_VIRTIO_DEBUG
278void virtio_debug_device_init(struct virtio_device *dev);
279void virtio_debug_device_exit(struct virtio_device *dev);
280void virtio_debug_device_filter_features(struct virtio_device *dev);
281void virtio_debug_init(void);
282void virtio_debug_exit(void);
283#else
284static inline void virtio_debug_device_init(struct virtio_device *dev)
285{
286}
287
288static inline void virtio_debug_device_exit(struct virtio_device *dev)
289{
290}
291
292static inline void virtio_debug_device_filter_features(struct virtio_device *dev)
293{
294}
295
296static inline void virtio_debug_init(void)
297{
298}
299
300static inline void virtio_debug_exit(void)
301{
302}
303#endif
304
305#endif /* _LINUX_VIRTIO_H */
306

source code of linux/include/linux/virtio.h

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