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 int virtqueue_reset(struct virtqueue *vq,
105 		    void (*recycle)(struct virtqueue *vq, void *buf));
106 
107 struct 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  */
137 struct 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 
160 void virtio_add_status(struct virtio_device *dev, unsigned int status);
161 int register_virtio_device(struct virtio_device *dev);
162 void unregister_virtio_device(struct virtio_device *dev);
163 bool is_virtio_device(struct device *dev);
164 
165 void virtio_break_device(struct virtio_device *dev);
166 void __virtio_unbreak_device(struct virtio_device *dev);
167 
168 void __virtqueue_break(struct virtqueue *_vq);
169 void __virtqueue_unbreak(struct virtqueue *_vq);
170 
171 void virtio_config_changed(struct virtio_device *dev);
172 
173 void virtio_config_driver_disable(struct virtio_device *dev);
174 void virtio_config_driver_enable(struct virtio_device *dev);
175 
176 #ifdef CONFIG_PM_SLEEP
177 int virtio_device_freeze(struct virtio_device *dev);
178 int virtio_device_restore(struct virtio_device *dev);
179 #endif
180 void virtio_reset_device(struct virtio_device *dev);
181 
182 size_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  */
206 struct 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)
227 int __register_virtio_driver(struct virtio_driver *drv, struct module *owner);
228 void 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 
239 dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr, size_t size,
240 					  enum dma_data_direction dir, unsigned long attrs);
241 void 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);
244 int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr);
245 
246 bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr);
247 void 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);
250 void 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
255 void virtio_debug_device_init(struct virtio_device *dev);
256 void virtio_debug_device_exit(struct virtio_device *dev);
257 void virtio_debug_device_filter_features(struct virtio_device *dev);
258 void virtio_debug_init(void);
259 void virtio_debug_exit(void);
260 #else
virtio_debug_device_init(struct virtio_device * dev)261 static inline void virtio_debug_device_init(struct virtio_device *dev)
262 {
263 }
264 
virtio_debug_device_exit(struct virtio_device * dev)265 static inline void virtio_debug_device_exit(struct virtio_device *dev)
266 {
267 }
268 
virtio_debug_device_filter_features(struct virtio_device * dev)269 static inline void virtio_debug_device_filter_features(struct virtio_device *dev)
270 {
271 }
272 
virtio_debug_init(void)273 static inline void virtio_debug_init(void)
274 {
275 }
276 
virtio_debug_exit(void)277 static inline void virtio_debug_exit(void)
278 {
279 }
280 #endif
281 
282 #endif /* _LINUX_VIRTIO_H */
283