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/vringh.h>
13
14 /**
15 * 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 *
24 * A note on @num_free: with indirect buffers, each buffer needs one
25 * element in the queue, otherwise a buffer will need one element per
26 * sg element.
27 */
28 struct virtqueue {
29 struct list_head list;
30 void (*callback)(struct virtqueue *vq);
31 const char *name;
32 struct virtio_device *vdev;
33 unsigned int index;
34 unsigned int num_free;
35 void *priv;
36 };
37
38 int virtqueue_add_outbuf(struct virtqueue *vq,
39 struct scatterlist sg[], unsigned int num,
40 void *data,
41 gfp_t gfp);
42
43 int virtqueue_add_inbuf(struct virtqueue *vq,
44 struct scatterlist sg[], unsigned int num,
45 void *data,
46 gfp_t gfp);
47
48 int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
49 struct scatterlist sg[], unsigned int num,
50 void *data,
51 void *ctx,
52 gfp_t gfp);
53
54 int virtqueue_add_sgs(struct virtqueue *vq,
55 struct scatterlist *sgs[],
56 unsigned int out_sgs,
57 unsigned int in_sgs,
58 void *data,
59 gfp_t gfp);
60
61 bool virtqueue_kick(struct virtqueue *vq);
62
63 bool virtqueue_kick_prepare(struct virtqueue *vq);
64
65 bool virtqueue_notify(struct virtqueue *vq);
66
67 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
68
69 void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
70 void **ctx);
71
72 void virtqueue_disable_cb(struct virtqueue *vq);
73
74 bool virtqueue_enable_cb(struct virtqueue *vq);
75
76 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
77
78 bool virtqueue_poll(struct virtqueue *vq, unsigned);
79
80 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
81
82 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
83
84 unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
85
86 bool virtqueue_is_broken(struct virtqueue *vq);
87
88 const struct vring *virtqueue_get_vring(struct virtqueue *vq);
89 dma_addr_t virtqueue_get_desc_addr(struct virtqueue *vq);
90 dma_addr_t virtqueue_get_avail_addr(struct virtqueue *vq);
91 dma_addr_t virtqueue_get_used_addr(struct virtqueue *vq);
92
93 /**
94 * virtio_device - representation of a device using virtio
95 * @index: unique position on the virtio bus
96 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
97 * @config_enabled: configuration change reporting enabled
98 * @config_change_pending: configuration change reported while disabled
99 * @config_lock: protects configuration change reporting
100 * @dev: underlying device.
101 * @id: the device type identification (used to match it with a driver).
102 * @config: the configuration ops for this device.
103 * @vringh_config: configuration ops for host vrings.
104 * @vqs: the list of virtqueues for this device.
105 * @features: the features supported by both driver and device.
106 * @priv: private pointer for the driver's use.
107 */
108 struct virtio_device {
109 int index;
110 bool failed;
111 bool config_enabled;
112 bool config_change_pending;
113 spinlock_t config_lock;
114 struct device dev;
115 struct virtio_device_id id;
116 const struct virtio_config_ops *config;
117 const struct vringh_config_ops *vringh_config;
118 struct list_head vqs;
119 u64 features;
120 void *priv;
121 };
122
dev_to_virtio(struct device * _dev)123 static inline struct virtio_device *dev_to_virtio(struct device *_dev)
124 {
125 return container_of(_dev, struct virtio_device, dev);
126 }
127
128 void virtio_add_status(struct virtio_device *dev, unsigned int status);
129 int register_virtio_device(struct virtio_device *dev);
130 void unregister_virtio_device(struct virtio_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
