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
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>
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.
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
31 struct list_head list;
32 void (*callback)(struct virtqueue *vq);
34 struct virtio_device *vdev;
36 unsigned int num_free;
42 int virtqueue_add_outbuf(struct virtqueue *vq,
43 struct scatterlist sg[], unsigned int num,
47 int virtqueue_add_inbuf(struct virtqueue *vq,
48 struct scatterlist sg[], unsigned int num,
52 int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
53 struct scatterlist sg[], unsigned int num,
58 int virtqueue_add_sgs(struct virtqueue *vq,
59 struct scatterlist *sgs[],
65 struct device *virtqueue_dma_dev(struct virtqueue *vq);
67 bool virtqueue_kick(struct virtqueue *vq);
69 bool virtqueue_kick_prepare(struct virtqueue *vq);
71 bool virtqueue_notify(struct virtqueue *vq);
73 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
75 void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
78 void virtqueue_disable_cb(struct virtqueue *vq);
80 bool virtqueue_enable_cb(struct virtqueue *vq);
82 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
84 int virtqueue_set_dma_premapped(struct virtqueue *_vq);
86 bool virtqueue_poll(struct virtqueue *vq, unsigned);
88 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
90 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
92 unsigned int virtqueue_get_vring_size(const struct virtqueue *vq);
94 bool virtqueue_is_broken(const struct virtqueue *vq);
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);
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));
106 struct virtio_admin_cmd {
109 __le64 group_member_id;
110 struct scatterlist *data_sg;
111 struct scatterlist *result_sg;
115 * struct virtio_device - representation of a device using virtio
116 * @index: unique position on the virtio bus
117 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
118 * @config_enabled: configuration change reporting enabled
119 * @config_change_pending: configuration change reported while disabled
120 * @config_lock: protects configuration change reporting
121 * @vqs_list_lock: protects @vqs.
122 * @dev: underlying device.
123 * @id: the device type identification (used to match it with a driver).
124 * @config: the configuration ops for this device.
125 * @vringh_config: configuration ops for host vrings.
126 * @vqs: the list of virtqueues for this device.
127 * @features: the features supported by both driver and device.
128 * @priv: private pointer for the driver's use.
130 struct virtio_device {
134 bool config_change_pending;
135 spinlock_t config_lock;
136 spinlock_t vqs_list_lock;
138 struct virtio_device_id id;
139 const struct virtio_config_ops *config;
140 const struct vringh_config_ops *vringh_config;
141 struct list_head vqs;
146 #define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev)
148 void virtio_add_status(struct virtio_device *dev, unsigned int status);
149 int register_virtio_device(struct virtio_device *dev);
150 void unregister_virtio_device(struct virtio_device *dev);
151 bool is_virtio_device(struct device *dev);
153 void virtio_break_device(struct virtio_device *dev);
154 void __virtio_unbreak_device(struct virtio_device *dev);
156 void __virtqueue_break(struct virtqueue *_vq);
157 void __virtqueue_unbreak(struct virtqueue *_vq);
159 void virtio_config_changed(struct virtio_device *dev);
160 #ifdef CONFIG_PM_SLEEP
161 int virtio_device_freeze(struct virtio_device *dev);
162 int virtio_device_restore(struct virtio_device *dev);
164 void virtio_reset_device(struct virtio_device *dev);
166 size_t virtio_max_dma_size(const struct virtio_device *vdev);
168 #define virtio_device_for_each_vq(vdev, vq) \
169 list_for_each_entry(vq, &vdev->vqs, list)
172 * struct virtio_driver - operations for a virtio I/O driver
173 * @driver: underlying device driver (populate name and owner).
174 * @id_table: the ids serviced by this driver.
175 * @feature_table: an array of feature numbers supported by this driver.
176 * @feature_table_size: number of entries in the feature table array.
177 * @feature_table_legacy: same as feature_table but when working in legacy mode.
178 * @feature_table_size_legacy: number of entries in feature table legacy array.
179 * @validate: the function to call to validate features and config space.
180 * Returns 0 or -errno.
181 * @probe: the function to call when a device is found. Returns 0 or -errno.
182 * @scan: optional function to call after successful probe; intended
183 * for virtio-scsi to invoke a scan.
184 * @remove: the function to call when a device is removed.
185 * @config_changed: optional function to call when the device configuration
186 * changes; may be called in interrupt context.
187 * @freeze: optional function to call during suspend/hibernation.
188 * @restore: optional function to call on resume.
190 struct virtio_driver {
191 struct device_driver driver;
192 const struct virtio_device_id *id_table;
193 const unsigned int *feature_table;
194 unsigned int feature_table_size;
195 const unsigned int *feature_table_legacy;
196 unsigned int feature_table_size_legacy;
197 int (*validate)(struct virtio_device *dev);
198 int (*probe)(struct virtio_device *dev);
199 void (*scan)(struct virtio_device *dev);
200 void (*remove)(struct virtio_device *dev);
201 void (*config_changed)(struct virtio_device *dev);
202 int (*freeze)(struct virtio_device *dev);
203 int (*restore)(struct virtio_device *dev);
206 static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
208 return container_of(drv, struct virtio_driver, driver);
211 int register_virtio_driver(struct virtio_driver *drv);
212 void unregister_virtio_driver(struct virtio_driver *drv);
214 /* module_virtio_driver() - Helper macro for drivers that don't do
215 * anything special in module init/exit. This eliminates a lot of
216 * boilerplate. Each module may only use this macro once, and
217 * calling it replaces module_init() and module_exit()
219 #define module_virtio_driver(__virtio_driver) \
220 module_driver(__virtio_driver, register_virtio_driver, \
221 unregister_virtio_driver)
223 dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr, size_t size,
224 enum dma_data_direction dir, unsigned long attrs);
225 void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr,
226 size_t size, enum dma_data_direction dir,
227 unsigned long attrs);
228 int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr);
230 bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr);
231 void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, dma_addr_t addr,
232 unsigned long offset, size_t size,
233 enum dma_data_direction dir);
234 void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr,
235 unsigned long offset, size_t size,
236 enum dma_data_direction dir);
237 #endif /* _LINUX_VIRTIO_H */