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