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
14 /**
15 * struct virtqueue - a queue to register buffers for sending or receiving.
16 * @list: the chain of virtqueues for this device
17 * @callback: the function to call when buffers are consumed (can be NULL).
18 * @name: the name of this virtqueue (mainly for debugging)
19 * @vdev: the virtio device this queue was created for.
20 * @priv: a pointer for the virtqueue implementation to use.
21 * @index: the zero-based ordinal number for this queue.
22 * @num_free: number of elements we expect to be able to fit.
23 * @num_max: the maximum number of elements supported by the device.
24 * @reset: vq is in reset state or not.
25 *
26 * A note on @num_free: with indirect buffers, each buffer needs one
27 * element in the queue, otherwise a buffer will need one element per
28 * sg element.
29 */
30 struct virtqueue {
31 struct list_head list;
32 void (*callback)(struct virtqueue *vq);
33 const char *name;
34 struct virtio_device *vdev;
35 unsigned int index;
36 unsigned int num_free;
37 unsigned int num_max;
38 bool reset;
39 void *priv;
40 };
41
42 int virtqueue_add_outbuf(struct virtqueue *vq,
43 struct scatterlist sg[], unsigned int num,
44 void *data,
45 gfp_t gfp);
46
47 int virtqueue_add_inbuf(struct virtqueue *vq,
48 struct scatterlist sg[], unsigned int num,
49 void *data,
50 gfp_t gfp);
51
52 int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
53 struct scatterlist sg[], unsigned int num,
54 void *data,
55 void *ctx,
56 gfp_t gfp);
57
58 int virtqueue_add_sgs(struct virtqueue *vq,
59 struct scatterlist *sgs[],
60 unsigned int out_sgs,
61 unsigned int in_sgs,
62 void *data,
63 gfp_t gfp);
64
65 struct device *virtqueue_dma_dev(struct virtqueue *vq);
66
67 bool virtqueue_kick(struct virtqueue *vq);
68
69 bool virtqueue_kick_prepare(struct virtqueue *vq);
70
71 bool virtqueue_notify(struct virtqueue *vq);
72
73 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
74
75 void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
76 void **ctx);
77
78 void virtqueue_disable_cb(struct virtqueue *vq);
79
80 bool virtqueue_enable_cb(struct virtqueue *vq);
81
82 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
83
84 int virtqueue_set_dma_premapped(struct virtqueue *_vq);
85
86 bool virtqueue_poll(struct virtqueue *vq, unsigned);
87
88 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
89
90 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
91
92 unsigned int virtqueue_get_vring_size(const struct virtqueue *vq);
93
94 bool virtqueue_is_broken(const struct virtqueue *vq);
95
96 const struct vring *virtqueue_get_vring(const struct virtqueue *vq);
97 dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq);
98 dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq);
99 dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq);
100
101 int virtqueue_resize(struct virtqueue *vq, u32 num,
102 void (*recycle)(struct virtqueue *vq, void *buf));
103 int virtqueue_reset(struct virtqueue *vq,
104 void (*recycle)(struct virtqueue *vq, void *buf));
105
106 void virtqueue_disable_dma_api_for_buffers(struct virtqueue *vq);
107
108 /**
109 * struct virtio_device - representation of a device using virtio
110 * @index: unique position on the virtio bus
111 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
112 * @config_enabled: configuration change reporting enabled
113 * @config_change_pending: configuration change reported while disabled
114 * @config_lock: protects configuration change reporting
115 * @vqs_list_lock: protects @vqs.
116 * @dev: underlying device.
117 * @id: the device type identification (used to match it with a driver).
118 * @config: the configuration ops for this device.
119 * @vringh_config: configuration ops for host vrings.
120 * @vqs: the list of virtqueues for this device.
121 * @features: the features supported by both driver and device.
122 * @priv: private pointer for the driver's use.
123 */
124 struct virtio_device {
125 int index;
126 bool failed;
127 bool config_enabled;
128 bool config_change_pending;
129 spinlock_t config_lock;
130 spinlock_t vqs_list_lock;
131 struct device dev;
132 struct virtio_device_id id;
133 const struct virtio_config_ops *config;
134 const struct vringh_config_ops *vringh_config;
135 struct list_head vqs;
136 u64 features;
137 void *priv;
138 };
139
140 #define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev)
141
142 void virtio_add_status(struct virtio_device *dev, unsigned int status);
143 int register_virtio_device(struct virtio_device *dev);
144 void unregister_virtio_device(struct virtio_device *dev);
145 bool is_virtio_device(struct device *dev);
146
147 void virtio_break_device(struct virtio_device *dev);
148 void __virtio_unbreak_device(struct virtio_device *dev);
149
150 void __virtqueue_break(struct virtqueue *_vq);
151 void __virtqueue_unbreak(struct virtqueue *_vq);
152
153 void virtio_config_changed(struct virtio_device *dev);
154 #ifdef CONFIG_PM_SLEEP
155 int virtio_device_freeze(struct virtio_device *dev);
156 int virtio_device_restore(struct virtio_device *dev);
157 #endif
158 void virtio_reset_device(struct virtio_device *dev);
159
160 size_t virtio_max_dma_size(const struct virtio_device *vdev);
161
162 #define virtio_device_for_each_vq(vdev, vq) \
163 list_for_each_entry(vq, &vdev->vqs, list)
164
165 /**
166 * struct virtio_driver - operations for a virtio I/O driver
167 * @driver: underlying device driver (populate name and owner).
168 * @id_table: the ids serviced by this driver.
169 * @feature_table: an array of feature numbers supported by this driver.
170 * @feature_table_size: number of entries in the feature table array.
171 * @feature_table_legacy: same as feature_table but when working in legacy mode.
172 * @feature_table_size_legacy: number of entries in feature table legacy array.
173 * @validate: the function to call to validate features and config space.
174 * Returns 0 or -errno.
175 * @probe: the function to call when a device is found. Returns 0 or -errno.
176 * @scan: optional function to call after successful probe; intended
177 * for virtio-scsi to invoke a scan.
178 * @remove: the function to call when a device is removed.
179 * @config_changed: optional function to call when the device configuration
180 * changes; may be called in interrupt context.
181 * @freeze: optional function to call during suspend/hibernation.
182 * @restore: optional function to call on resume.
183 */
184 struct virtio_driver {
185 struct device_driver driver;
186 const struct virtio_device_id *id_table;
187 const unsigned int *feature_table;
188 unsigned int feature_table_size;
189 const unsigned int *feature_table_legacy;
190 unsigned int feature_table_size_legacy;
191 int (*validate)(struct virtio_device *dev);
192 int (*probe)(struct virtio_device *dev);
193 void (*scan)(struct virtio_device *dev);
194 void (*remove)(struct virtio_device *dev);
195 void (*config_changed)(struct virtio_device *dev);
196 int (*freeze)(struct virtio_device *dev);
197 int (*restore)(struct virtio_device *dev);
198 };
199
drv_to_virtio(struct device_driver * drv)200 static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
201 {
202 return container_of(drv, struct virtio_driver, driver);
203 }
204
205 int register_virtio_driver(struct virtio_driver *drv);
206 void unregister_virtio_driver(struct virtio_driver *drv);
207
208 /* module_virtio_driver() - Helper macro for drivers that don't do
209 * anything special in module init/exit. This eliminates a lot of
210 * boilerplate. Each module may only use this macro once, and
211 * calling it replaces module_init() and module_exit()
212 */
213 #define module_virtio_driver(__virtio_driver) \
214 module_driver(__virtio_driver, register_virtio_driver, \
215 unregister_virtio_driver)
216
217 dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr, size_t size,
218 enum dma_data_direction dir, unsigned long attrs);
219 void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr,
220 size_t size, enum dma_data_direction dir,
221 unsigned long attrs);
222 int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr);
223
224 bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr);
225 void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, dma_addr_t addr,
226 unsigned long offset, size_t size,
227 enum dma_data_direction dir);
228 void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr,
229 unsigned long offset, size_t size,
230 enum dma_data_direction dir);
231 #endif /* _LINUX_VIRTIO_H */
232