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 */ 27 struct 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 37 int virtqueue_add_outbuf(struct virtqueue *vq, 38 struct scatterlist sg[], unsigned int num, 39 void *data, 40 gfp_t gfp); 41 42 int virtqueue_add_inbuf(struct virtqueue *vq, 43 struct scatterlist sg[], unsigned int num, 44 void *data, 45 gfp_t gfp); 46 47 int 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 54 void virtqueue_kick(struct virtqueue *vq); 55 56 bool virtqueue_kick_prepare(struct virtqueue *vq); 57 58 void virtqueue_notify(struct virtqueue *vq); 59 60 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); 61 62 void virtqueue_disable_cb(struct virtqueue *vq); 63 64 bool virtqueue_enable_cb(struct virtqueue *vq); 65 66 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq); 67 68 bool virtqueue_poll(struct virtqueue *vq, unsigned); 69 70 bool virtqueue_enable_cb_delayed(struct virtqueue *vq); 71 72 void *virtqueue_detach_unused_buf(struct virtqueue *vq); 73 74 unsigned int virtqueue_get_vring_size(struct virtqueue *vq); 75 76 /** 77 * virtio_device - representation of a device using virtio 78 * @index: unique position on the virtio bus 79 * @dev: underlying device. 80 * @id: the device type identification (used to match it with a driver). 81 * @config: the configuration ops for this device. 82 * @vringh_config: configuration ops for host vrings. 83 * @vqs: the list of virtqueues for this device. 84 * @features: the features supported by both driver and device. 85 * @priv: private pointer for the driver's use. 86 */ 87 struct virtio_device { 88 int index; 89 struct device dev; 90 struct virtio_device_id id; 91 const struct virtio_config_ops *config; 92 const struct vringh_config_ops *vringh_config; 93 struct list_head vqs; 94 /* Note that this is a Linux set_bit-style bitmap. */ 95 unsigned long features[1]; 96 void *priv; 97 }; 98 99 static inline struct virtio_device *dev_to_virtio(struct device *_dev) 100 { 101 return container_of(_dev, struct virtio_device, dev); 102 } 103 104 int register_virtio_device(struct virtio_device *dev); 105 void unregister_virtio_device(struct virtio_device *dev); 106 107 /** 108 * virtio_driver - operations for a virtio I/O driver 109 * @driver: underlying device driver (populate name and owner). 110 * @id_table: the ids serviced by this driver. 111 * @feature_table: an array of feature numbers supported by this driver. 112 * @feature_table_size: number of entries in the feature table array. 113 * @probe: the function to call when a device is found. Returns 0 or -errno. 114 * @remove: the function to call when a device is removed. 115 * @config_changed: optional function to call when the device configuration 116 * changes; may be called in interrupt context. 117 */ 118 struct virtio_driver { 119 struct device_driver driver; 120 const struct virtio_device_id *id_table; 121 const unsigned int *feature_table; 122 unsigned int feature_table_size; 123 int (*probe)(struct virtio_device *dev); 124 void (*scan)(struct virtio_device *dev); 125 void (*remove)(struct virtio_device *dev); 126 void (*config_changed)(struct virtio_device *dev); 127 #ifdef CONFIG_PM 128 int (*freeze)(struct virtio_device *dev); 129 int (*restore)(struct virtio_device *dev); 130 #endif 131 }; 132 133 static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv) 134 { 135 return container_of(drv, struct virtio_driver, driver); 136 } 137 138 int register_virtio_driver(struct virtio_driver *drv); 139 void unregister_virtio_driver(struct virtio_driver *drv); 140 141 /* module_virtio_driver() - Helper macro for drivers that don't do 142 * anything special in module init/exit. This eliminates a lot of 143 * boilerplate. Each module may only use this macro once, and 144 * calling it replaces module_init() and module_exit() 145 */ 146 #define module_virtio_driver(__virtio_driver) \ 147 module_driver(__virtio_driver, register_virtio_driver, \ 148 unregister_virtio_driver) 149 #endif /* _LINUX_VIRTIO_H */ 150