LXR linux/include/linux/virtio.h

   1/* SPDX-License-Identifier: GPL-2.0 */
   2#ifndef _LINUX_VIRTIO_H
   3#define _LINUX_VIRTIO_H
   4/* Everything a virtio driver needs to work with any particular virtio
   5 * implementation. */
   6#include <linux/types.h>
   7#include <linux/scatterlist.h>
   8#include <linux/spinlock.h>
   9#include <linux/device.h>
  10#include <linux/mod_devicetable.h>
  11#include <linux/gfp.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_inbuf_ctx(struct virtqueue *vq,
  48                            struct scatterlist sg[], unsigned int num,
  49                            void *data,
  50                            void *ctx,
  51                            gfp_t gfp);
  52
  53int virtqueue_add_sgs(struct virtqueue *vq,
  54                      struct scatterlist *sgs[],
  55                      unsigned int out_sgs,
  56                      unsigned int in_sgs,
  57                      void *data,
  58                      gfp_t gfp);
  59
  60bool virtqueue_kick(struct virtqueue *vq);
  61
  62bool virtqueue_kick_prepare(struct virtqueue *vq);
  63
  64bool virtqueue_notify(struct virtqueue *vq);
  65
  66void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
  67
  68void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
  69                            void **ctx);
  70
  71void virtqueue_disable_cb(struct virtqueue *vq);
  72
  73bool virtqueue_enable_cb(struct virtqueue *vq);
  74
  75unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
  76
  77bool virtqueue_poll(struct virtqueue *vq, unsigned);
  78
  79bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
  80
  81void *virtqueue_detach_unused_buf(struct virtqueue *vq);
  82
  83unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
  84
  85bool virtqueue_is_broken(struct virtqueue *vq);
  86
  87const struct vring *virtqueue_get_vring(struct virtqueue *vq);
  88dma_addr_t virtqueue_get_desc_addr(struct virtqueue *vq);
  89dma_addr_t virtqueue_get_avail_addr(struct virtqueue *vq);
  90dma_addr_t virtqueue_get_used_addr(struct virtqueue *vq);
  91
  92/**
  93 * virtio_device - representation of a device using virtio
  94 * @index: unique position on the virtio bus
  95 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
  96 * @config_enabled: configuration change reporting enabled
  97 * @config_change_pending: configuration change reported while disabled
  98 * @config_lock: protects configuration change reporting
  99 * @dev: underlying device.
 100 * @id: the device type identification (used to match it with a driver).
 101 * @config: the configuration ops for this device.
 102 * @vringh_config: configuration ops for host vrings.
 103 * @vqs: the list of virtqueues for this device.
 104 * @features: the features supported by both driver and device.
 105 * @priv: private pointer for the driver's use.
 106 */
 107struct virtio_device {
 108        int index;
 109        bool failed;
 110        bool config_enabled;
 111        bool config_change_pending;
 112        spinlock_t config_lock;
 113        struct device dev;
 114        struct virtio_device_id id;
 115        const struct virtio_config_ops *config;
 116        const struct vringh_config_ops *vringh_config;
 117        struct list_head vqs;
 118        u64 features;
 119        void *priv;
 120};
 121
 122static inline struct virtio_device *dev_to_virtio(struct device *_dev)
 123{
 124        return container_of(_dev, struct virtio_device, dev);
 125}
 126
 127void virtio_add_status(struct virtio_device *dev, unsigned int status);
 128int register_virtio_device(struct virtio_device *dev);
 129void unregister_virtio_device(struct virtio_device *dev);
 130bool is_virtio_device(struct device *dev);
 131
 132void virtio_break_device(struct virtio_device *dev);
 133
 134void virtio_config_changed(struct virtio_device *dev);
 135int virtio_finalize_features(struct virtio_device *dev);
 136#ifdef CONFIG_PM_SLEEP
 137int virtio_device_freeze(struct virtio_device *dev);
 138int virtio_device_restore(struct virtio_device *dev);
 139#endif
 140
 141size_t virtio_max_dma_size(struct virtio_device *vdev);
 142
 143#define virtio_device_for_each_vq(vdev, vq) \
 144        list_for_each_entry(vq, &vdev->vqs, list)
 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 * @scan: optional function to call after successful probe; intended
 156 *    for virtio-scsi to invoke a scan.
 157 * @remove: the function to call when a device is removed.
 158 * @config_changed: optional function to call when the device configuration
 159 *    changes; may be called in interrupt context.
 160 * @freeze: optional function to call during suspend/hibernation.
 161 * @restore: optional function to call on resume.
 162 */
 163struct virtio_driver {
 164        struct device_driver driver;
 165        const struct virtio_device_id *id_table;
 166        const unsigned int *feature_table;
 167        unsigned int feature_table_size;
 168        const unsigned int *feature_table_legacy;
 169        unsigned int feature_table_size_legacy;
 170        int (*validate)(struct virtio_device *dev);
 171        int (*probe)(struct virtio_device *dev);
 172        void (*scan)(struct virtio_device *dev);
 173        void (*remove)(struct virtio_device *dev);
 174        void (*config_changed)(struct virtio_device *dev);
 175#ifdef CONFIG_PM
 176        int (*freeze)(struct virtio_device *dev);
 177        int (*restore)(struct virtio_device *dev);
 178#endif
 179};
 180
 181static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
 182{
 183        return container_of(drv, struct virtio_driver, driver);
 184}
 185
 186int register_virtio_driver(struct virtio_driver *drv);
 187void unregister_virtio_driver(struct virtio_driver *drv);
 188
 189/* module_virtio_driver() - Helper macro for drivers that don't do
 190 * anything special in module init/exit.  This eliminates a lot of
 191 * boilerplate.  Each module may only use this macro once, and
 192 * calling it replaces module_init() and module_exit()
 193 */
 194#define module_virtio_driver(__virtio_driver) \
 195        module_driver(__virtio_driver, register_virtio_driver, \
 196                        unregister_virtio_driver)
 197#endif /* _LINUX_VIRTIO_H */
 198