include/linux/virtio.h

   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  */
  20 struct virtqueue {
  21         struct list_head list;
  22         void (*callback)(struct virtqueue *vq);
  23         const char *name;
  24         struct virtio_device *vdev;
  25         void *priv;
  26 };
  27
  28 int virtqueue_add_buf(struct virtqueue *vq,
  29                       struct scatterlist sg[],
  30                       unsigned int out_num,
  31                       unsigned int in_num,
  32                       void *data,
  33                       gfp_t gfp);
  34
  35 void virtqueue_kick(struct virtqueue *vq);
  36
  37 bool virtqueue_kick_prepare(struct virtqueue *vq);
  38
  39 void virtqueue_notify(struct virtqueue *vq);
  40
  41 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
  42
  43 void virtqueue_disable_cb(struct virtqueue *vq);
  44
  45 bool virtqueue_enable_cb(struct virtqueue *vq);
  46
  47 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
  48
  49 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
  50
  51 unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
  52
  53 /**
  54  * virtio_device - representation of a device using virtio
  55  * @index: unique position on the virtio bus
  56  * @dev: underlying device.
  57  * @id: the device type identification (used to match it with a driver).
  58  * @config: the configuration ops for this device.
  59  * @vqs: the list of virtqueues for this device.
  60  * @features: the features supported by both driver and device.
  61  * @priv: private pointer for the driver's use.
  62  */
  63 struct virtio_device {
  64         int index;
  65         struct device dev;
  66         struct virtio_device_id id;
  67         struct virtio_config_ops *config;
  68         struct list_head vqs;
  69         /* Note that this is a Linux set_bit-style bitmap. */
  70         unsigned long features[1];
  71         void *priv;
  72 };
  73
  74 #define dev_to_virtio(dev) container_of(dev, struct virtio_device, dev)
  75 int register_virtio_device(struct virtio_device *dev);
  76 void unregister_virtio_device(struct virtio_device *dev);
  77
  78 /**
  79  * virtio_driver - operations for a virtio I/O driver
  80  * @driver: underlying device driver (populate name and owner).
  81  * @id_table: the ids serviced by this driver.
  82  * @feature_table: an array of feature numbers supported by this driver.
  83  * @feature_table_size: number of entries in the feature table array.
  84  * @probe: the function to call when a device is found.  Returns 0 or -errno.
  85  * @remove: the function to call when a device is removed.
  86  * @config_changed: optional function to call when the device configuration
  87  *    changes; may be called in interrupt context.
  88  */
  89 struct virtio_driver {
  90         struct device_driver driver;
  91         const struct virtio_device_id *id_table;
  92         const unsigned int *feature_table;
  93         unsigned int feature_table_size;
  94         int (*probe)(struct virtio_device *dev);
  95         void (*remove)(struct virtio_device *dev);
  96         void (*config_changed)(struct virtio_device *dev);
  97 #ifdef CONFIG_PM
  98         int (*freeze)(struct virtio_device *dev);
  99         int (*thaw)(struct virtio_device *dev);
 100         int (*restore)(struct virtio_device *dev);
 101 #endif
 102 };
 103
 104 int register_virtio_driver(struct virtio_driver *drv);
 105 void unregister_virtio_driver(struct virtio_driver *drv);
 106 #endif /* _LINUX_VIRTIO_H */