1#ifndef _LINUX_VIRTIO_H 2#define _LINUX_VIRTIO_H 3/* Everything a virtio driver needs to work with any particular virtio 4 * implementation. */ 5#include <linux/types.h> 6#include <linux/scatterlist.h> 7#include <linux/spinlock.h> 8#include <linux/device.h> 9#include <linux/mod_devicetable.h> 10#include <linux/gfp.h> 11#include <linux/vringh.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 */ 27struct 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 37int virtqueue_add_outbuf(struct virtqueue *vq, 38 struct scatterlist sg[], unsigned int num, 39 void *data, 40 gfp_t gfp); 41 42int virtqueue_add_inbuf(struct virtqueue *vq, 43 struct scatterlist sg[], unsigned int num, 44 void *data, 45 gfp_t gfp); 46 47int virtqueue_add_sgs(struct virtqueue *vq, 48 struct scatterlist *sgs[], 49 unsigned int out_sgs, 50 unsigned int in_sgs, 51 void *data, 52 gfp_t gfp); 53 54bool virtqueue_kick(struct virtqueue *vq); 55 56bool virtqueue_kick_prepare(struct virtqueue *vq); 57 58bool virtqueue_notify(struct virtqueue *vq); 59 60void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); 61 62void virtqueue_disable_cb(struct virtqueue *vq); 63 64bool virtqueue_enable_cb(struct virtqueue *vq); 65 66unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq); 67 68bool virtqueue_poll(struct virtqueue *vq, unsigned); 69 70bool virtqueue_enable_cb_delayed(struct virtqueue *vq); 71 72void *virtqueue_detach_unused_buf(struct virtqueue *vq); 73 74unsigned int virtqueue_get_vring_size(struct virtqueue *vq); 75 76bool virtqueue_is_broken(struct virtqueue *vq); 77 78void *virtqueue_get_avail(struct virtqueue *vq); 79void *virtqueue_get_used(struct virtqueue *vq); 80 81/** 82 * virtio_device - representation of a device using virtio 83 * @index: unique position on the virtio bus 84 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore) 85 * @config_enabled: configuration change reporting enabled 86 * @config_change_pending: configuration change reported while disabled 87 * @config_lock: protects configuration change reporting 88 * @dev: underlying device. 89 * @id: the device type identification (used to match it with a driver). 90 * @config: the configuration ops for this device. 91 * @vringh_config: configuration ops for host vrings. 92 * @vqs: the list of virtqueues for this device. 93 * @features: the features supported by both driver and device. 94 * @priv: private pointer for the driver's use. 95 */ 96struct virtio_device { 97 int index; 98 bool failed; 99 bool config_enabled; 100 bool config_change_pending; 101 spinlock_t config_lock; 102 struct device dev; 103 struct virtio_device_id id; 104 const struct virtio_config_ops *config; 105 const struct vringh_config_ops *vringh_config; 106 struct list_head vqs; 107 u64 features; 108 void *priv; 109}; 110 111static inline struct virtio_device *dev_to_virtio(struct device *_dev) 112{ 113 return container_of(_dev, struct virtio_device, dev); 114} 115 116int register_virtio_device(struct virtio_device *dev); 117void unregister_virtio_device(struct virtio_device *dev); 118 119void virtio_break_device(struct virtio_device *dev); 120 121void virtio_config_changed(struct virtio_device *dev); 122#ifdef CONFIG_PM_SLEEP 123int virtio_device_freeze(struct virtio_device *dev); 124int virtio_device_restore(struct virtio_device *dev); 125#endif 126 127/** 128 * virtio_driver - operations for a virtio I/O driver 129 * @driver: underlying device driver (populate name and owner). 130 * @id_table: the ids serviced by this driver. 131 * @feature_table: an array of feature numbers supported by this driver. 132 * @feature_table_size: number of entries in the feature table array. 133 * @feature_table_legacy: same as feature_table but when working in legacy mode. 134 * @feature_table_size_legacy: number of entries in feature table legacy array. 135 * @probe: the function to call when a device is found. Returns 0 or -errno. 136 * @remove: the function to call when a device is removed. 137 * @config_changed: optional function to call when the device configuration 138 * changes; may be called in interrupt context. 139 */ 140struct virtio_driver { 141 struct device_driver driver; 142 const struct virtio_device_id *id_table; 143 const unsigned int *feature_table; 144 unsigned int feature_table_size; 145 const unsigned int *feature_table_legacy; 146 unsigned int feature_table_size_legacy; 147 int (*probe)(struct virtio_device *dev); 148 void (*scan)(struct virtio_device *dev); 149 void (*remove)(struct virtio_device *dev); 150 void (*config_changed)(struct virtio_device *dev); 151#ifdef CONFIG_PM 152 int (*freeze)(struct virtio_device *dev); 153 int (*restore)(struct virtio_device *dev); 154#endif 155}; 156 157static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv) 158{ 159 return container_of(drv, struct virtio_driver, driver); 160} 161 162int register_virtio_driver(struct virtio_driver *drv); 163void unregister_virtio_driver(struct virtio_driver *drv); 164 165/* module_virtio_driver() - Helper macro for drivers that don't do 166 * anything special in module init/exit. This eliminates a lot of 167 * boilerplate. Each module may only use this macro once, and 168 * calling it replaces module_init() and module_exit() 169 */ 170#define module_virtio_driver(__virtio_driver) \ 171 module_driver(__virtio_driver, register_virtio_driver, \ 172 unregister_virtio_driver) 173#endif /* _LINUX_VIRTIO_H */ 174