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
  78const struct vring *virtqueue_get_vring(struct virtqueue *vq);
  79dma_addr_t virtqueue_get_desc_addr(struct virtqueue *vq);
  80dma_addr_t virtqueue_get_avail_addr(struct virtqueue *vq);
  81dma_addr_t virtqueue_get_used_addr(struct virtqueue *vq);
  82
  83/*
  84 * Legacy accessors -- in almost all cases, these are the wrong functions
  85 * to use.
  86 */
  87static inline void *virtqueue_get_desc(struct virtqueue *vq)
  88{
  89        return virtqueue_get_vring(vq)->desc;
  90}
  91static inline void *virtqueue_get_avail(struct virtqueue *vq)
  92{
  93        return virtqueue_get_vring(vq)->avail;
  94}
  95static inline void *virtqueue_get_used(struct virtqueue *vq)
  96{
  97        return virtqueue_get_vring(vq)->used;
  98}
  99
 100/**
 101 * virtio_device - representation of a device using virtio
 102 * @index: unique position on the virtio bus
 103 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
 104 * @config_enabled: configuration change reporting enabled
 105 * @config_change_pending: configuration change reported while disabled
 106 * @config_lock: protects configuration change reporting
 107 * @dev: underlying device.
 108 * @id: the device type identification (used to match it with a driver).
 109 * @config: the configuration ops for this device.
 110 * @vringh_config: configuration ops for host vrings.
 111 * @vqs: the list of virtqueues for this device.
 112 * @features: the features supported by both driver and device.
 113 * @priv: private pointer for the driver's use.
 114 */
 115struct virtio_device {
 116        int index;
 117        bool failed;
 118        bool config_enabled;
 119        bool config_change_pending;
 120        spinlock_t config_lock;
 121        struct device dev;
 122        struct virtio_device_id id;
 123        const struct virtio_config_ops *config;
 124        const struct vringh_config_ops *vringh_config;
 125        struct list_head vqs;
 126        u64 features;
 127        void *priv;
 128};
 129
 130static inline struct virtio_device *dev_to_virtio(struct device *_dev)
 131{
 132        return container_of(_dev, struct virtio_device, dev);
 133}
 134
 135int register_virtio_device(struct virtio_device *dev);
 136void unregister_virtio_device(struct virtio_device *dev);
 137
 138void virtio_break_device(struct virtio_device *dev);
 139
 140void virtio_config_changed(struct virtio_device *dev);
 141#ifdef CONFIG_PM_SLEEP
 142int virtio_device_freeze(struct virtio_device *dev);
 143int virtio_device_restore(struct virtio_device *dev);
 144#endif
 145
 146/**
 147 * virtio_driver - operations for a virtio I/O driver
 148 * @driver: underlying device driver (populate name and owner).
 149 * @id_table: the ids serviced by this driver.
 150 * @feature_table: an array of feature numbers supported by this driver.
 151 * @feature_table_size: number of entries in the feature table array.
 152 * @feature_table_legacy: same as feature_table but when working in legacy mode.
 153 * @feature_table_size_legacy: number of entries in feature table legacy array.
 154 * @probe: the function to call when a device is found.  Returns 0 or -errno.
 155 * @remove: the function to call when a device is removed.
 156 * @config_changed: optional function to call when the device configuration
 157 *    changes; may be called in interrupt context.
 158 */
 159struct virtio_driver {
 160        struct device_driver driver;
 161        const struct virtio_device_id *id_table;
 162        const unsigned int *feature_table;
 163        unsigned int feature_table_size;
 164        const unsigned int *feature_table_legacy;
 165        unsigned int feature_table_size_legacy;
 166        int (*probe)(struct virtio_device *dev);
 167        void (*scan)(struct virtio_device *dev);
 168        void (*remove)(struct virtio_device *dev);
 169        void (*config_changed)(struct virtio_device *dev);
 170#ifdef CONFIG_PM
 171        int (*freeze)(struct virtio_device *dev);
 172        int (*restore)(struct virtio_device *dev);
 173#endif
 174};
 175
 176static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
 177{
 178        return container_of(drv, struct virtio_driver, driver);
 179}
 180
 181int register_virtio_driver(struct virtio_driver *drv);
 182void unregister_virtio_driver(struct virtio_driver *drv);
 183
 184/* module_virtio_driver() - Helper macro for drivers that don't do
 185 * anything special in module init/exit.  This eliminates a lot of
 186 * boilerplate.  Each module may only use this macro once, and
 187 * calling it replaces module_init() and module_exit()
 188 */
 189#define module_virtio_driver(__virtio_driver) \
 190        module_driver(__virtio_driver, register_virtio_driver, \
 191                        unregister_virtio_driver)
 192#endif /* _LINUX_VIRTIO_H */
 193