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