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 /* FIXME: Obsolete accessor, but required for virtio_net merge. */ 62 static inline unsigned int virtqueue_get_queue_index(struct virtqueue *vq) 63 { 64 return vq->index; 65 } 66 67 /** 68 * virtio_device - representation of a device using virtio 69 * @index: unique position on the virtio bus 70 * @dev: underlying device. 71 * @id: the device type identification (used to match it with a driver). 72 * @config: the configuration ops for this device. 73 * @vqs: the list of virtqueues for this device. 74 * @features: the features supported by both driver and device. 75 * @priv: private pointer for the driver's use. 76 */ 77 struct virtio_device { 78 int index; 79 struct device dev; 80 struct virtio_device_id id; 81 struct virtio_config_ops *config; 82 struct list_head vqs; 83 /* Note that this is a Linux set_bit-style bitmap. */ 84 unsigned long features[1]; 85 void *priv; 86 }; 87 88 static inline struct virtio_device *dev_to_virtio(struct device *_dev) 89 { 90 return container_of(_dev, struct virtio_device, dev); 91 } 92 93 int register_virtio_device(struct virtio_device *dev); 94 void unregister_virtio_device(struct virtio_device *dev); 95 96 /** 97 * virtio_driver - operations for a virtio I/O driver 98 * @driver: underlying device driver (populate name and owner). 99 * @id_table: the ids serviced by this driver. 100 * @feature_table: an array of feature numbers supported by this driver. 101 * @feature_table_size: number of entries in the feature table array. 102 * @probe: the function to call when a device is found. Returns 0 or -errno. 103 * @remove: the function to call when a device is removed. 104 * @config_changed: optional function to call when the device configuration 105 * changes; may be called in interrupt context. 106 */ 107 struct virtio_driver { 108 struct device_driver driver; 109 const struct virtio_device_id *id_table; 110 const unsigned int *feature_table; 111 unsigned int feature_table_size; 112 int (*probe)(struct virtio_device *dev); 113 void (*scan)(struct virtio_device *dev); 114 void (*remove)(struct virtio_device *dev); 115 void (*config_changed)(struct virtio_device *dev); 116 #ifdef CONFIG_PM 117 int (*freeze)(struct virtio_device *dev); 118 int (*restore)(struct virtio_device *dev); 119 #endif 120 }; 121 122 static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv) 123 { 124 return container_of(drv, struct virtio_driver, driver); 125 } 126 127 int register_virtio_driver(struct virtio_driver *drv); 128 void unregister_virtio_driver(struct virtio_driver *drv); 129 #endif /* _LINUX_VIRTIO_H */ 130