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
13 /**
14 * struct virtqueue - a queue to register buffers for sending or receiving.
15 * @list: the chain of virtqueues for this device
16 * @callback: the function to call when buffers are consumed (can be NULL).
17 * @name: the name of this virtqueue (mainly for debugging)
18 * @vdev: the virtio device this queue was created for.
19 * @priv: a pointer for the virtqueue implementation to use.
20 * @index: the zero-based ordinal number for this queue.
21 * @num_free: number of elements we expect to be able to fit.
22 * @num_max: the maximum number of elements supported by the device.
23 * @reset: vq is in reset state or not.
24 *
25 * A note on @num_free: with indirect buffers, each buffer needs one
26 * element in the queue, otherwise a buffer will need one element per
27 * sg element.
28 */
29 struct virtqueue {
30 struct list_head list;
31 void (*callback)(struct virtqueue *vq);
32 const char *name;
33 struct virtio_device *vdev;
34 unsigned int index;
35 unsigned int num_free;
36 unsigned int num_max;
37 void *priv;
38 bool reset;
39 };
40
41 int virtqueue_add_outbuf(struct virtqueue *vq,
42 struct scatterlist sg[], unsigned int num,
43 void *data,
44 gfp_t gfp);
45
46 int virtqueue_add_inbuf(struct virtqueue *vq,
47 struct scatterlist sg[], unsigned int num,
48 void *data,
49 gfp_t gfp);
50
51 int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
52 struct scatterlist sg[], unsigned int num,
53 void *data,
54 void *ctx,
55 gfp_t gfp);
56
57 int virtqueue_add_sgs(struct virtqueue *vq,
58 struct scatterlist *sgs[],
59 unsigned int out_sgs,
60 unsigned int in_sgs,
61 void *data,
62 gfp_t gfp);
63
64 bool virtqueue_kick(struct virtqueue *vq);
65
66 bool virtqueue_kick_prepare(struct virtqueue *vq);
67
68 bool virtqueue_notify(struct virtqueue *vq);
69
70 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
71
72 void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
73 void **ctx);
74
75 void virtqueue_disable_cb(struct virtqueue *vq);
76
77 bool virtqueue_enable_cb(struct virtqueue *vq);
78
79 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
80
81 bool virtqueue_poll(struct virtqueue *vq, unsigned);
82
83 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
84
85 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
86
87 unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
88
89 bool virtqueue_is_broken(struct virtqueue *vq);
90
91 const struct vring *virtqueue_get_vring(struct virtqueue *vq);
92 dma_addr_t virtqueue_get_desc_addr(struct virtqueue *vq);
93 dma_addr_t virtqueue_get_avail_addr(struct virtqueue *vq);
94 dma_addr_t virtqueue_get_used_addr(struct virtqueue *vq);
95
96 int virtqueue_resize(struct virtqueue *vq, u32 num,
97 void (*recycle)(struct virtqueue *vq, void *buf));
98
99 /**
100 * struct virtio_device - representation of a device using virtio
101 * @index: unique position on the virtio bus
102 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
103 * @config_enabled: configuration change reporting enabled
104 * @config_change_pending: configuration change reported while disabled
105 * @config_lock: protects configuration change reporting
106 * @dev: underlying device.
107 * @id: the device type identification (used to match it with a driver).
108 * @config: the configuration ops for this device.
109 * @vringh_config: configuration ops for host vrings.
110 * @vqs: the list of virtqueues for this device.
111 * @features: the features supported by both driver and device.
112 * @priv: private pointer for the driver's use.
113 */
114 struct virtio_device {
115 int index;
116 bool failed;
117 bool config_enabled;
118 bool config_change_pending;
119 spinlock_t config_lock;
120 spinlock_t vqs_list_lock; /* Protects VQs list access */
121 struct device dev;
122 struct virtio_device_id id;
123 const struct virtio_config_ops *config;
124 const struct vringh_config_ops *vringh_config;
125 struct list_head vqs;
126 u64 features;
127 void *priv;
128 };
129
dev_to_virtio(struct device * _dev)130 static inline struct virtio_device *dev_to_virtio(struct device *_dev)
131 {
132 return container_of(_dev, struct virtio_device, dev);
133 }
134
135 void virtio_add_status(struct virtio_device *dev, unsigned int status);
136 int register_virtio_device(struct virtio_device *dev);
137 void unregister_virtio_device(struct virtio_device *dev);
138 bool is_virtio_device(struct device *dev);
139
140 void virtio_break_device(struct virtio_device *dev);
141 void __virtio_unbreak_device(struct virtio_device *dev);
142
143 void __virtqueue_break(struct virtqueue *_vq);
144 void __virtqueue_unbreak(struct virtqueue *_vq);
145
146 void virtio_config_changed(struct virtio_device *dev);
147 #ifdef CONFIG_PM_SLEEP
148 int virtio_device_freeze(struct virtio_device *dev);
149 int virtio_device_restore(struct virtio_device *dev);
150 #endif
151 void virtio_reset_device(struct virtio_device *dev);
152
153 size_t virtio_max_dma_size(struct virtio_device *vdev);
154
155 #define virtio_device_for_each_vq(vdev, vq) \
156 list_for_each_entry(vq, &vdev->vqs, list)
157
158 /**
159 * struct virtio_driver - operations for a virtio I/O driver
160 * @driver: underlying device driver (populate name and owner).
161 * @id_table: the ids serviced by this driver.
162 * @feature_table: an array of feature numbers supported by this driver.
163 * @feature_table_size: number of entries in the feature table array.
164 * @feature_table_legacy: same as feature_table but when working in legacy mode.
165 * @feature_table_size_legacy: number of entries in feature table legacy array.
166 * @probe: the function to call when a device is found. Returns 0 or -errno.
167 * @scan: optional function to call after successful probe; intended
168 * for virtio-scsi to invoke a scan.
169 * @remove: the function to call when a device is removed.
170 * @config_changed: optional function to call when the device configuration
171 * changes; may be called in interrupt context.
172 * @freeze: optional function to call during suspend/hibernation.
173 * @restore: optional function to call on resume.
174 */
175 struct virtio_driver {
176 struct device_driver driver;
177 const struct virtio_device_id *id_table;
178 const unsigned int *feature_table;
179 unsigned int feature_table_size;
180 const unsigned int *feature_table_legacy;
181 unsigned int feature_table_size_legacy;
182 int (*validate)(struct virtio_device *dev);
183 int (*probe)(struct virtio_device *dev);
184 void (*scan)(struct virtio_device *dev);
185 void (*remove)(struct virtio_device *dev);
186 void (*config_changed)(struct virtio_device *dev);
187 #ifdef CONFIG_PM
188 int (*freeze)(struct virtio_device *dev);
189 int (*restore)(struct virtio_device *dev);
190 #endif
191 };
192
drv_to_virtio(struct device_driver * drv)193 static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
194 {
195 return container_of(drv, struct virtio_driver, driver);
196 }
197
198 int register_virtio_driver(struct virtio_driver *drv);
199 void unregister_virtio_driver(struct virtio_driver *drv);
200
201 /* module_virtio_driver() - Helper macro for drivers that don't do
202 * anything special in module init/exit. This eliminates a lot of
203 * boilerplate. Each module may only use this macro once, and
204 * calling it replaces module_init() and module_exit()
205 */
206 #define module_virtio_driver(__virtio_driver) \
207 module_driver(__virtio_driver, register_virtio_driver, \
208 unregister_virtio_driver)
209 #endif /* _LINUX_VIRTIO_H */
210