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 #include <linux/virtio_features.h>
15
16 struct module;
17
18 /**
19 * struct virtqueue - a queue to register buffers for sending or receiving.
20 * @list: the chain of virtqueues for this device
21 * @callback: the function to call when buffers are consumed (can be NULL).
22 * @name: the name of this virtqueue (mainly for debugging)
23 * @vdev: the virtio device this queue was created for.
24 * @priv: a pointer for the virtqueue implementation to use.
25 * @index: the zero-based ordinal number for this queue.
26 * @num_free: number of elements we expect to be able to fit.
27 * @num_max: the maximum number of elements supported by the device.
28 * @reset: vq is in reset state or not.
29 *
30 * A note on @num_free: with indirect buffers, each buffer needs one
31 * element in the queue, otherwise a buffer will need one element per
32 * sg element.
33 */
34 struct virtqueue {
35 struct list_head list;
36 void (*callback)(struct virtqueue *vq);
37 const char *name;
38 struct virtio_device *vdev;
39 unsigned int index;
40 unsigned int num_free;
41 unsigned int num_max;
42 bool reset;
43 void *priv;
44 };
45
46 struct vduse_iova_domain;
47
48 union virtio_map {
49 /* Device that performs DMA */
50 struct device *dma_dev;
51 /* VDUSE specific mapping data */
52 struct vduse_iova_domain *iova_domain;
53 };
54
55 int virtqueue_add_outbuf(struct virtqueue *vq,
56 struct scatterlist sg[], unsigned int num,
57 void *data,
58 gfp_t gfp);
59
60 int virtqueue_add_inbuf(struct virtqueue *vq,
61 struct scatterlist sg[], unsigned int num,
62 void *data,
63 gfp_t gfp);
64
65 int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
66 struct scatterlist sg[], unsigned int num,
67 void *data,
68 void *ctx,
69 gfp_t gfp);
70
71 int virtqueue_add_inbuf_premapped(struct virtqueue *vq,
72 struct scatterlist *sg, unsigned int num,
73 void *data,
74 void *ctx,
75 gfp_t gfp);
76
77 int virtqueue_add_outbuf_premapped(struct virtqueue *vq,
78 struct scatterlist *sg, unsigned int num,
79 void *data,
80 gfp_t gfp);
81
82 int virtqueue_add_sgs(struct virtqueue *vq,
83 struct scatterlist *sgs[],
84 unsigned int out_sgs,
85 unsigned int in_sgs,
86 void *data,
87 gfp_t gfp);
88
89 struct device *virtqueue_dma_dev(struct virtqueue *vq);
90
91 bool virtqueue_kick(struct virtqueue *vq);
92
93 bool virtqueue_kick_prepare(struct virtqueue *vq);
94
95 bool virtqueue_notify(struct virtqueue *vq);
96
97 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
98
99 void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
100 void **ctx);
101
102 void virtqueue_disable_cb(struct virtqueue *vq);
103
104 bool virtqueue_enable_cb(struct virtqueue *vq);
105
106 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
107
108 bool virtqueue_poll(struct virtqueue *vq, unsigned);
109
110 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
111
112 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
113
114 unsigned int virtqueue_get_vring_size(const struct virtqueue *vq);
115
116 bool virtqueue_is_broken(const struct virtqueue *vq);
117
118 const struct vring *virtqueue_get_vring(const struct virtqueue *vq);
119 dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq);
120 dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq);
121 dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq);
122
123 int virtqueue_resize(struct virtqueue *vq, u32 num,
124 void (*recycle)(struct virtqueue *vq, void *buf),
125 void (*recycle_done)(struct virtqueue *vq));
126 int virtqueue_reset(struct virtqueue *vq,
127 void (*recycle)(struct virtqueue *vq, void *buf),
128 void (*recycle_done)(struct virtqueue *vq));
129
130 struct virtio_admin_cmd {
131 __le16 opcode;
132 __le16 group_type;
133 __le64 group_member_id;
134 struct scatterlist *data_sg;
135 struct scatterlist *result_sg;
136 struct completion completion;
137 u32 result_sg_size;
138 int ret;
139 };
140
141 /**
142 * struct virtio_device - representation of a device using virtio
143 * @index: unique position on the virtio bus
144 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
145 * @config_core_enabled: configuration change reporting enabled by core
146 * @config_driver_disabled: configuration change reporting disabled by
147 * a driver
148 * @config_change_pending: configuration change reported while disabled
149 * @config_lock: protects configuration change reporting
150 * @vqs_list_lock: protects @vqs.
151 * @dev: underlying device.
152 * @id: the device type identification (used to match it with a driver).
153 * @config: the configuration ops for this device.
154 * @vringh_config: configuration ops for host vrings.
155 * @vqs: the list of virtqueues for this device.
156 * @features: the 64 lower features supported by both driver and device.
157 * @features_array: the full features space supported by both driver and
158 * device.
159 * @priv: private pointer for the driver's use.
160 * @debugfs_dir: debugfs directory entry.
161 * @debugfs_filter_features: features to be filtered set by debugfs.
162 */
163 struct virtio_device {
164 int index;
165 bool failed;
166 bool config_core_enabled;
167 bool config_driver_disabled;
168 bool config_change_pending;
169 spinlock_t config_lock;
170 spinlock_t vqs_list_lock;
171 struct device dev;
172 struct virtio_device_id id;
173 const struct virtio_config_ops *config;
174 const struct vringh_config_ops *vringh_config;
175 const struct virtio_map_ops *map;
176 struct list_head vqs;
177 VIRTIO_DECLARE_FEATURES(features);
178 void *priv;
179 union virtio_map vmap;
180 #ifdef CONFIG_VIRTIO_DEBUG
181 struct dentry *debugfs_dir;
182 u64 debugfs_filter_features[VIRTIO_FEATURES_U64S];
183 #endif
184 };
185
186 #define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev)
187
188 void virtio_add_status(struct virtio_device *dev, unsigned int status);
189 int register_virtio_device(struct virtio_device *dev);
190 void unregister_virtio_device(struct virtio_device *dev);
191 bool is_virtio_device(struct device *dev);
192
193 void virtio_break_device(struct virtio_device *dev);
194 void __virtio_unbreak_device(struct virtio_device *dev);
195
196 void __virtqueue_break(struct virtqueue *_vq);
197 void __virtqueue_unbreak(struct virtqueue *_vq);
198
199 void virtio_config_changed(struct virtio_device *dev);
200
201 void virtio_config_driver_disable(struct virtio_device *dev);
202 void virtio_config_driver_enable(struct virtio_device *dev);
203
204 #ifdef CONFIG_PM_SLEEP
205 int virtio_device_freeze(struct virtio_device *dev);
206 int virtio_device_restore(struct virtio_device *dev);
207 #endif
208 void virtio_reset_device(struct virtio_device *dev);
209 int virtio_device_reset_prepare(struct virtio_device *dev);
210 int virtio_device_reset_done(struct virtio_device *dev);
211
212 size_t virtio_max_dma_size(const struct virtio_device *vdev);
213
214 #define virtio_device_for_each_vq(vdev, vq) \
215 list_for_each_entry(vq, &(vdev)->vqs, list)
216
217 /**
218 * struct virtio_driver - operations for a virtio I/O driver
219 * @driver: underlying device driver (populate name).
220 * @id_table: the ids serviced by this driver.
221 * @feature_table: an array of feature numbers supported by this driver.
222 * @feature_table_size: number of entries in the feature table array.
223 * @feature_table_legacy: same as feature_table but when working in legacy mode.
224 * @feature_table_size_legacy: number of entries in feature table legacy array.
225 * @validate: the function to call to validate features and config space.
226 * Returns 0 or -errno.
227 * @probe: the function to call when a device is found. Returns 0 or -errno.
228 * @scan: optional function to call after successful probe; intended
229 * for virtio-scsi to invoke a scan.
230 * @remove: the function to call when a device is removed.
231 * @config_changed: optional function to call when the device configuration
232 * changes; may be called in interrupt context.
233 * @freeze: optional function to call during suspend/hibernation.
234 * @restore: optional function to call on resume.
235 * @reset_prepare: optional function to call when a transport specific reset
236 * occurs.
237 * @reset_done: optional function to call after transport specific reset
238 * operation has finished.
239 * @shutdown: synchronize with the device on shutdown. If provided, replaces
240 * the virtio core implementation.
241 */
242 struct virtio_driver {
243 struct device_driver driver;
244 const struct virtio_device_id *id_table;
245 const unsigned int *feature_table;
246 unsigned int feature_table_size;
247 const unsigned int *feature_table_legacy;
248 unsigned int feature_table_size_legacy;
249 int (*validate)(struct virtio_device *dev);
250 int (*probe)(struct virtio_device *dev);
251 void (*scan)(struct virtio_device *dev);
252 void (*remove)(struct virtio_device *dev);
253 void (*config_changed)(struct virtio_device *dev);
254 int (*freeze)(struct virtio_device *dev);
255 int (*restore)(struct virtio_device *dev);
256 int (*reset_prepare)(struct virtio_device *dev);
257 int (*reset_done)(struct virtio_device *dev);
258 void (*shutdown)(struct virtio_device *dev);
259 };
260
261 #define drv_to_virtio(__drv) container_of_const(__drv, struct virtio_driver, driver)
262
263 /* use a macro to avoid include chaining to get THIS_MODULE */
264 #define register_virtio_driver(drv) \
265 __register_virtio_driver(drv, THIS_MODULE)
266 int __register_virtio_driver(struct virtio_driver *drv, struct module *owner);
267 void unregister_virtio_driver(struct virtio_driver *drv);
268
269 /* module_virtio_driver() - Helper macro for drivers that don't do
270 * anything special in module init/exit. This eliminates a lot of
271 * boilerplate. Each module may only use this macro once, and
272 * calling it replaces module_init() and module_exit()
273 */
274 #define module_virtio_driver(__virtio_driver) \
275 module_driver(__virtio_driver, register_virtio_driver, \
276 unregister_virtio_driver)
277
278
279 void *virtqueue_map_alloc_coherent(struct virtio_device *vdev,
280 union virtio_map mapping_token,
281 size_t size, dma_addr_t *dma_handle,
282 gfp_t gfp);
283
284 void virtqueue_map_free_coherent(struct virtio_device *vdev,
285 union virtio_map mapping_token,
286 size_t size, void *vaddr,
287 dma_addr_t dma_handle);
288
289 dma_addr_t virtqueue_map_page_attrs(const struct virtqueue *_vq,
290 struct page *page,
291 unsigned long offset,
292 size_t size,
293 enum dma_data_direction dir,
294 unsigned long attrs);
295
296 void virtqueue_unmap_page_attrs(const struct virtqueue *_vq,
297 dma_addr_t dma_handle,
298 size_t size, enum dma_data_direction dir,
299 unsigned long attrs);
300
301 dma_addr_t virtqueue_map_single_attrs(const struct virtqueue *_vq, void *ptr, size_t size,
302 enum dma_data_direction dir, unsigned long attrs);
303 void virtqueue_unmap_single_attrs(const struct virtqueue *_vq, dma_addr_t addr,
304 size_t size, enum dma_data_direction dir,
305 unsigned long attrs);
306 int virtqueue_map_mapping_error(const struct virtqueue *_vq, dma_addr_t addr);
307
308 bool virtqueue_map_need_sync(const struct virtqueue *_vq, dma_addr_t addr);
309 void virtqueue_map_sync_single_range_for_cpu(const struct virtqueue *_vq, dma_addr_t addr,
310 unsigned long offset, size_t size,
311 enum dma_data_direction dir);
312 void virtqueue_map_sync_single_range_for_device(const struct virtqueue *_vq, dma_addr_t addr,
313 unsigned long offset, size_t size,
314 enum dma_data_direction dir);
315
316 #ifdef CONFIG_VIRTIO_DEBUG
317 void virtio_debug_device_init(struct virtio_device *dev);
318 void virtio_debug_device_exit(struct virtio_device *dev);
319 void virtio_debug_device_filter_features(struct virtio_device *dev);
320 void virtio_debug_init(void);
321 void virtio_debug_exit(void);
322 #else
virtio_debug_device_init(struct virtio_device * dev)323 static inline void virtio_debug_device_init(struct virtio_device *dev)
324 {
325 }
326
virtio_debug_device_exit(struct virtio_device * dev)327 static inline void virtio_debug_device_exit(struct virtio_device *dev)
328 {
329 }
330
virtio_debug_device_filter_features(struct virtio_device * dev)331 static inline void virtio_debug_device_filter_features(struct virtio_device *dev)
332 {
333 }
334
virtio_debug_init(void)335 static inline void virtio_debug_init(void)
336 {
337 }
338
virtio_debug_exit(void)339 static inline void virtio_debug_exit(void)
340 {
341 }
342 #endif
343
344 #endif /* _LINUX_VIRTIO_H */
345