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 12 /** 13 * virtqueue - a queue to register buffers for sending or receiving. 14 * @list: the chain of virtqueues for this device 15 * @callback: the function to call when buffers are consumed (can be NULL). 16 * @name: the name of this virtqueue (mainly for debugging) 17 * @vdev: the virtio device this queue was created for. 18 * @priv: a pointer for the virtqueue implementation to use. 19 * @index: the zero-based ordinal number for this queue. 20 * @num_free: number of elements we expect to be able to fit. 21 * 22 * A note on @num_free: with indirect buffers, each buffer needs one 23 * element in the queue, otherwise a buffer will need one element per 24 * sg element. 25 */ 26 struct virtqueue { 27 struct list_head list; 28 void (*callback)(struct virtqueue *vq); 29 const char *name; 30 struct virtio_device *vdev; 31 unsigned int index; 32 unsigned int num_free; 33 void *priv; 34 }; 35 36 int virtqueue_add_buf(struct virtqueue *vq, 37 struct scatterlist sg[], 38 unsigned int out_num, 39 unsigned int in_num, 40 void *data, 41 gfp_t gfp); 42 43 void virtqueue_kick(struct virtqueue *vq); 44 45 bool virtqueue_kick_prepare(struct virtqueue *vq); 46 47 void virtqueue_notify(struct virtqueue *vq); 48 49 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); 50 51 void virtqueue_disable_cb(struct virtqueue *vq); 52 53 bool virtqueue_enable_cb(struct virtqueue *vq); 54 55 bool virtqueue_enable_cb_delayed(struct virtqueue *vq); 56 57 void *virtqueue_detach_unused_buf(struct virtqueue *vq); 58 59 unsigned int virtqueue_get_vring_size(struct virtqueue *vq); 60 61 /** 62 * virtio_device - representation of a device using virtio 63 * @index: unique position on the virtio bus 64 * @dev: underlying device. 65 * @id: the device type identification (used to match it with a driver). 66 * @config: the configuration ops for this device. 67 * @vqs: the list of virtqueues for this device. 68 * @features: the features supported by both driver and device. 69 * @priv: private pointer for the driver's use. 70 */ 71 struct virtio_device { 72 int index; 73 struct device dev; 74 struct virtio_device_id id; 75 const struct virtio_config_ops *config; 76 struct list_head vqs; 77 /* Note that this is a Linux set_bit-style bitmap. */ 78 unsigned long features[1]; 79 void *priv; 80 }; 81 82 static inline struct virtio_device *dev_to_virtio(struct device *_dev) 83 { 84 return container_of(_dev, struct virtio_device, dev); 85 } 86 87 int register_virtio_device(struct virtio_device *dev); 88 void unregister_virtio_device(struct virtio_device *dev); 89 90 /** 91 * virtio_driver - operations for a virtio I/O driver 92 * @driver: underlying device driver (populate name and owner). 93 * @id_table: the ids serviced by this driver. 94 * @feature_table: an array of feature numbers supported by this driver. 95 * @feature_table_size: number of entries in the feature table array. 96 * @probe: the function to call when a device is found. Returns 0 or -errno. 97 * @remove: the function to call when a device is removed. 98 * @config_changed: optional function to call when the device configuration 99 * changes; may be called in interrupt context. 100 */ 101 struct virtio_driver { 102 struct device_driver driver; 103 const struct virtio_device_id *id_table; 104 const unsigned int *feature_table; 105 unsigned int feature_table_size; 106 int (*probe)(struct virtio_device *dev); 107 void (*scan)(struct virtio_device *dev); 108 void (*remove)(struct virtio_device *dev); 109 void (*config_changed)(struct virtio_device *dev); 110 #ifdef CONFIG_PM 111 int (*freeze)(struct virtio_device *dev); 112 int (*restore)(struct virtio_device *dev); 113 #endif 114 }; 115 116 static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv) 117 { 118 return container_of(drv, struct virtio_driver, driver); 119 } 120 121 int register_virtio_driver(struct virtio_driver *drv); 122 void unregister_virtio_driver(struct virtio_driver *drv); 123 124 /* module_virtio_driver() - Helper macro for drivers that don't do 125 * anything special in module init/exit. This eliminates a lot of 126 * boilerplate. Each module may only use this macro once, and 127 * calling it replaces module_init() and module_exit() 128 */ 129 #define module_virtio_driver(__virtio_driver) \ 130 module_driver(__virtio_driver, register_virtio_driver, \ 131 unregister_virtio_driver) 132 #endif /* _LINUX_VIRTIO_H */ 133