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