LXR linux/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#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
  78/**
  79 * virtio_device - representation of a device using virtio
  80 * @index: unique position on the virtio bus
  81 * @dev: underlying device.
  82 * @id: the device type identification (used to match it with a driver).
  83 * @config: the configuration ops for this device.
  84 * @vringh_config: configuration ops for host vrings.
  85 * @vqs: the list of virtqueues for this device.
  86 * @features: the features supported by both driver and device.
  87 * @priv: private pointer for the driver's use.
  88 */
  89struct virtio_device {
  90        int index;
  91        struct device dev;
  92        struct virtio_device_id id;
  93        const struct virtio_config_ops *config;
  94        const struct vringh_config_ops *vringh_config;
  95        struct list_head vqs;
  96        /* Note that this is a Linux set_bit-style bitmap. */
  97        unsigned long features[1];
  98        void *priv;
  99};
 100
 101static inline struct virtio_device *dev_to_virtio(struct device *_dev)
 102{
 103        return container_of(_dev, struct virtio_device, dev);
 104}
 105
 106int register_virtio_device(struct virtio_device *dev);
 107void unregister_virtio_device(struct virtio_device *dev);
 108
 109void virtio_break_device(struct virtio_device *dev);
 110
 111/**
 112 * virtio_driver - operations for a virtio I/O driver
 113 * @driver: underlying device driver (populate name and owner).
 114 * @id_table: the ids serviced by this driver.
 115 * @feature_table: an array of feature numbers supported by this driver.
 116 * @feature_table_size: number of entries in the feature table array.
 117 * @probe: the function to call when a device is found.  Returns 0 or -errno.
 118 * @remove: the function to call when a device is removed.
 119 * @config_changed: optional function to call when the device configuration
 120 *    changes; may be called in interrupt context.
 121 */
 122struct virtio_driver {
 123        struct device_driver driver;
 124        const struct virtio_device_id *id_table;
 125        const unsigned int *feature_table;
 126        unsigned int feature_table_size;
 127        int (*probe)(struct virtio_device *dev);
 128        void (*scan)(struct virtio_device *dev);
 129        void (*remove)(struct virtio_device *dev);
 130        void (*config_changed)(struct virtio_device *dev);
 131#ifdef CONFIG_PM
 132        int (*freeze)(struct virtio_device *dev);
 133        int (*restore)(struct virtio_device *dev);
 134#endif
 135};
 136
 137static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
 138{
 139        return container_of(drv, struct virtio_driver, driver);
 140}
 141
 142int register_virtio_driver(struct virtio_driver *drv);
 143void unregister_virtio_driver(struct virtio_driver *drv);
 144
 145/* module_virtio_driver() - Helper macro for drivers that don't do
 146 * anything special in module init/exit.  This eliminates a lot of
 147 * boilerplate.  Each module may only use this macro once, and
 148 * calling it replaces module_init() and module_exit()
 149 */
 150#define module_virtio_driver(__virtio_driver) \
 151        module_driver(__virtio_driver, register_virtio_driver, \
 152                        unregister_virtio_driver)
 153#endif /* _LINUX_VIRTIO_H */
 154