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_core_enabled: configuration change reporting enabled by core
122 * @config_driver_disabled: configuration change reporting disabled by
123 * a driver
124 * @config_change_pending: configuration change reported while disabled
125 * @config_lock: protects configuration change reporting
126 * @vqs_list_lock: protects @vqs.
127 * @dev: underlying device.
128 * @id: the device type identification (used to match it with a driver).
129 * @config: the configuration ops for this device.
130 * @vringh_config: configuration ops for host vrings.
131 * @vqs: the list of virtqueues for this device.
132 * @features: the features supported by both driver and device.
133 * @priv: private pointer for the driver's use.
134 * @debugfs_dir: debugfs directory entry.
135 * @debugfs_filter_features: features to be filtered set by debugfs.
136 */
137struct virtio_device {
138 int index;
139 bool failed;
140 bool config_core_enabled;
141 bool config_driver_disabled;
142 bool config_change_pending;
143 spinlock_t config_lock;
144 spinlock_t vqs_list_lock;
145 struct device dev;
146 struct virtio_device_id id;
147 const struct virtio_config_ops *config;
148 const struct vringh_config_ops *vringh_config;
149 struct list_head vqs;
150 u64 features;
151 void *priv;
152#ifdef CONFIG_VIRTIO_DEBUG
153 struct dentry *debugfs_dir;
154 u64 debugfs_filter_features;
155#endif
156};
157
158#define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev)
159
160void virtio_add_status(struct virtio_device *dev, unsigned int status);
161int register_virtio_device(struct virtio_device *dev);
162void unregister_virtio_device(struct virtio_device *dev);
163bool is_virtio_device(struct device *dev);
164
165void virtio_break_device(struct virtio_device *dev);
166void __virtio_unbreak_device(struct virtio_device *dev);
167
168void __virtqueue_break(struct virtqueue *_vq);
169void __virtqueue_unbreak(struct virtqueue *_vq);
170
171void virtio_config_changed(struct virtio_device *dev);
172
173void virtio_config_driver_disable(struct virtio_device *dev);
174void virtio_config_driver_enable(struct virtio_device *dev);
175
176#ifdef CONFIG_PM_SLEEP
177int virtio_device_freeze(struct virtio_device *dev);
178int virtio_device_restore(struct virtio_device *dev);
179#endif
180void virtio_reset_device(struct virtio_device *dev);
181
182size_t virtio_max_dma_size(const struct virtio_device *vdev);
183
184#define virtio_device_for_each_vq(vdev, vq) \
185 list_for_each_entry(vq, &vdev->vqs, list)
186
187/**
188 * struct virtio_driver - operations for a virtio I/O driver
189 * @driver: underlying device driver (populate name).
190 * @id_table: the ids serviced by this driver.
191 * @feature_table: an array of feature numbers supported by this driver.
192 * @feature_table_size: number of entries in the feature table array.
193 * @feature_table_legacy: same as feature_table but when working in legacy mode.
194 * @feature_table_size_legacy: number of entries in feature table legacy array.
195 * @validate: the function to call to validate features and config space.
196 * Returns 0 or -errno.
197 * @probe: the function to call when a device is found. Returns 0 or -errno.
198 * @scan: optional function to call after successful probe; intended
199 * for virtio-scsi to invoke a scan.
200 * @remove: the function to call when a device is removed.
201 * @config_changed: optional function to call when the device configuration
202 * changes; may be called in interrupt context.
203 * @freeze: optional function to call during suspend/hibernation.
204 * @restore: optional function to call on resume.
205 */
206struct virtio_driver {
207 struct device_driver driver;
208 const struct virtio_device_id *id_table;
209 const unsigned int *feature_table;
210 unsigned int feature_table_size;
211 const unsigned int *feature_table_legacy;
212 unsigned int feature_table_size_legacy;
213 int (*validate)(struct virtio_device *dev);
214 int (*probe)(struct virtio_device *dev);
215 void (*scan)(struct virtio_device *dev);
216 void (*remove)(struct virtio_device *dev);
217 void (*config_changed)(struct virtio_device *dev);
218 int (*freeze)(struct virtio_device *dev);
219 int (*restore)(struct virtio_device *dev);
220};
221
222#define drv_to_virtio(__drv) container_of_const(__drv, struct virtio_driver, driver)
223
224/* use a macro to avoid include chaining to get THIS_MODULE */
225#define register_virtio_driver(drv) \
226 __register_virtio_driver(drv, THIS_MODULE)
227int __register_virtio_driver(struct virtio_driver *drv, struct module *owner);
228void unregister_virtio_driver(struct virtio_driver *drv);
229
230/* module_virtio_driver() - Helper macro for drivers that don't do
231 * anything special in module init/exit. This eliminates a lot of
232 * boilerplate. Each module may only use this macro once, and
233 * calling it replaces module_init() and module_exit()
234 */
235#define module_virtio_driver(__virtio_driver) \
236 module_driver(__virtio_driver, register_virtio_driver, \
237 unregister_virtio_driver)
238
239dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr, size_t size,
240 enum dma_data_direction dir, unsigned long attrs);
241void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr,
242 size_t size, enum dma_data_direction dir,
243 unsigned long attrs);
244int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr);
245
246bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr);
247void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, dma_addr_t addr,
248 unsigned long offset, size_t size,
249 enum dma_data_direction dir);
250void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr,
251 unsigned long offset, size_t size,
252 enum dma_data_direction dir);
253
254#ifdef CONFIG_VIRTIO_DEBUG
255void virtio_debug_device_init(struct virtio_device *dev);
256void virtio_debug_device_exit(struct virtio_device *dev);
257void virtio_debug_device_filter_features(struct virtio_device *dev);
258void virtio_debug_init(void);
259void virtio_debug_exit(void);
260#else
261static inline void virtio_debug_device_init(struct virtio_device *dev)
262{
263}
264
265static inline void virtio_debug_device_exit(struct virtio_device *dev)
266{
267}
268
269static inline void virtio_debug_device_filter_features(struct virtio_device *dev)
270{
271}
272
273static inline void virtio_debug_init(void)
274{
275}
276
277static inline void virtio_debug_exit(void)
278{
279}
280#endif
281
282#endif /* _LINUX_VIRTIO_H */