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 */
31 struct 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
43 int virtqueue_add_outbuf(struct virtqueue *vq,
44 struct scatterlist sg[], unsigned int num,
45 void *data,
46 gfp_t gfp);
47
48 int virtqueue_add_inbuf(struct virtqueue *vq,
49 struct scatterlist sg[], unsigned int num,
50 void *data,
51 gfp_t gfp);
52
53 int 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
59 int 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
65 int virtqueue_add_outbuf_premapped(struct virtqueue *vq,
66 struct scatterlist *sg, unsigned int num,
67 void *data,
68 gfp_t gfp);
69
70 int 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
77 struct device *virtqueue_dma_dev(struct virtqueue *vq);
78
79 bool virtqueue_kick(struct virtqueue *vq);
80
81 bool virtqueue_kick_prepare(struct virtqueue *vq);
82
83 bool virtqueue_notify(struct virtqueue *vq);
84
85 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
86
87 void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
88 void **ctx);
89
90 void virtqueue_disable_cb(struct virtqueue *vq);
91
92 bool virtqueue_enable_cb(struct virtqueue *vq);
93
94 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
95
96 bool virtqueue_poll(struct virtqueue *vq, unsigned);
97
98 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
99
100 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
101
102 unsigned int virtqueue_get_vring_size(const struct virtqueue *vq);
103
104 bool virtqueue_is_broken(const struct virtqueue *vq);
105
106 const struct vring *virtqueue_get_vring(const struct virtqueue *vq);
107 dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq);
108 dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq);
109 dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq);
110
111 int virtqueue_resize(struct virtqueue *vq, u32 num,
112 void (*recycle)(struct virtqueue *vq, void *buf),
113 void (*recycle_done)(struct virtqueue *vq));
114 int virtqueue_reset(struct virtqueue *vq,
115 void (*recycle)(struct virtqueue *vq, void *buf),
116 void (*recycle_done)(struct virtqueue *vq));
117
118 struct 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 */
149 struct 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
172 void virtio_add_status(struct virtio_device *dev, unsigned int status);
173 int register_virtio_device(struct virtio_device *dev);
174 void unregister_virtio_device(struct virtio_device *dev);
175 bool is_virtio_device(struct device *dev);
176
177 void virtio_break_device(struct virtio_device *dev);
178 void __virtio_unbreak_device(struct virtio_device *dev);
179
180 void __virtqueue_break(struct virtqueue *_vq);
181 void __virtqueue_unbreak(struct virtqueue *_vq);
182
183 void virtio_config_changed(struct virtio_device *dev);
184
185 void virtio_config_driver_disable(struct virtio_device *dev);
186 void virtio_config_driver_enable(struct virtio_device *dev);
187
188 #ifdef CONFIG_PM_SLEEP
189 int virtio_device_freeze(struct virtio_device *dev);
190 int virtio_device_restore(struct virtio_device *dev);
191 #endif
192 void virtio_reset_device(struct virtio_device *dev);
193
194 size_t virtio_max_dma_size(const struct virtio_device *vdev);
195
196 #define virtio_device_for_each_vq(vdev, vq) \
197 list_for_each_entry(vq, &vdev->vqs, list)
198
199 /**
200 * struct virtio_driver - operations for a virtio I/O driver
201 * @driver: underlying device driver (populate name).
202 * @id_table: the ids serviced by this driver.
203 * @feature_table: an array of feature numbers supported by this driver.
204 * @feature_table_size: number of entries in the feature table array.
205 * @feature_table_legacy: same as feature_table but when working in legacy mode.
206 * @feature_table_size_legacy: number of entries in feature table legacy array.
207 * @validate: the function to call to validate features and config space.
208 * Returns 0 or -errno.
209 * @probe: the function to call when a device is found. Returns 0 or -errno.
210 * @scan: optional function to call after successful probe; intended
211 * for virtio-scsi to invoke a scan.
212 * @remove: the function to call when a device is removed.
213 * @config_changed: optional function to call when the device configuration
214 * changes; may be called in interrupt context.
215 * @freeze: optional function to call during suspend/hibernation.
216 * @restore: optional function to call on resume.
217 */
218 struct virtio_driver {
219 struct device_driver driver;
220 const struct virtio_device_id *id_table;
221 const unsigned int *feature_table;
222 unsigned int feature_table_size;
223 const unsigned int *feature_table_legacy;
224 unsigned int feature_table_size_legacy;
225 int (*validate)(struct virtio_device *dev);
226 int (*probe)(struct virtio_device *dev);
227 void (*scan)(struct virtio_device *dev);
228 void (*remove)(struct virtio_device *dev);
229 void (*config_changed)(struct virtio_device *dev);
230 int (*freeze)(struct virtio_device *dev);
231 int (*restore)(struct virtio_device *dev);
232 };
233
234 #define drv_to_virtio(__drv) container_of_const(__drv, struct virtio_driver, driver)
235
236 /* use a macro to avoid include chaining to get THIS_MODULE */
237 #define register_virtio_driver(drv) \
238 __register_virtio_driver(drv, THIS_MODULE)
239 int __register_virtio_driver(struct virtio_driver *drv, struct module *owner);
240 void unregister_virtio_driver(struct virtio_driver *drv);
241
242 /* module_virtio_driver() - Helper macro for drivers that don't do
243 * anything special in module init/exit. This eliminates a lot of
244 * boilerplate. Each module may only use this macro once, and
245 * calling it replaces module_init() and module_exit()
246 */
247 #define module_virtio_driver(__virtio_driver) \
248 module_driver(__virtio_driver, register_virtio_driver, \
249 unregister_virtio_driver)
250
251 dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr, size_t size,
252 enum dma_data_direction dir, unsigned long attrs);
253 void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr,
254 size_t size, enum dma_data_direction dir,
255 unsigned long attrs);
256 int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr);
257
258 bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr);
259 void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, dma_addr_t addr,
260 unsigned long offset, size_t size,
261 enum dma_data_direction dir);
262 void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr,
263 unsigned long offset, size_t size,
264 enum dma_data_direction dir);
265
266 #ifdef CONFIG_VIRTIO_DEBUG
267 void virtio_debug_device_init(struct virtio_device *dev);
268 void virtio_debug_device_exit(struct virtio_device *dev);
269 void virtio_debug_device_filter_features(struct virtio_device *dev);
270 void virtio_debug_init(void);
271 void virtio_debug_exit(void);
272 #else
virtio_debug_device_init(struct virtio_device * dev)273 static inline void virtio_debug_device_init(struct virtio_device *dev)
274 {
275 }
276
virtio_debug_device_exit(struct virtio_device * dev)277 static inline void virtio_debug_device_exit(struct virtio_device *dev)
278 {
279 }
280
virtio_debug_device_filter_features(struct virtio_device * dev)281 static inline void virtio_debug_device_filter_features(struct virtio_device *dev)
282 {
283 }
284
virtio_debug_init(void)285 static inline void virtio_debug_init(void)
286 {
287 }
288
virtio_debug_exit(void)289 static inline void virtio_debug_exit(void)
290 {
291 }
292 #endif
293
294 #endif /* _LINUX_VIRTIO_H */
295