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       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                 :            : #include <linux/vringh.h>
      13                 :            : 
      14                 :            : /**
      15                 :            :  * virtqueue - a queue to register buffers for sending or receiving.
      16                 :            :  * @list: the chain of virtqueues for this device
      17                 :            :  * @callback: the function to call when buffers are consumed (can be NULL).
      18                 :            :  * @name: the name of this virtqueue (mainly for debugging)
      19                 :            :  * @vdev: the virtio device this queue was created for.
      20                 :            :  * @priv: a pointer for the virtqueue implementation to use.
      21                 :            :  * @index: the zero-based ordinal number for this queue.
      22                 :            :  * @num_free: number of elements we expect to be able to fit.
      23                 :            :  *
      24                 :            :  * A note on @num_free: with indirect buffers, each buffer needs one
      25                 :            :  * element in the queue, otherwise a buffer will need one element per
      26                 :            :  * sg element.
      27                 :            :  */
      28                 :            : struct virtqueue {
      29                 :            :         struct list_head list;
      30                 :            :         void (*callback)(struct virtqueue *vq);
      31                 :            :         const char *name;
      32                 :            :         struct virtio_device *vdev;
      33                 :            :         unsigned int index;
      34                 :            :         unsigned int num_free;
      35                 :            :         void *priv;
      36                 :            : };
      37                 :            : 
      38                 :            : int virtqueue_add_outbuf(struct virtqueue *vq,
      39                 :            :                          struct scatterlist sg[], unsigned int num,
      40                 :            :                          void *data,
      41                 :            :                          gfp_t gfp);
      42                 :            : 
      43                 :            : int virtqueue_add_inbuf(struct virtqueue *vq,
      44                 :            :                         struct scatterlist sg[], unsigned int num,
      45                 :            :                         void *data,
      46                 :            :                         gfp_t gfp);
      47                 :            : 
      48                 :            : int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
      49                 :            :                             struct scatterlist sg[], unsigned int num,
      50                 :            :                             void *data,
      51                 :            :                             void *ctx,
      52                 :            :                             gfp_t gfp);
      53                 :            : 
      54                 :            : int virtqueue_add_sgs(struct virtqueue *vq,
      55                 :            :                       struct scatterlist *sgs[],
      56                 :            :                       unsigned int out_sgs,
      57                 :            :                       unsigned int in_sgs,
      58                 :            :                       void *data,
      59                 :            :                       gfp_t gfp);
      60                 :            : 
      61                 :            : bool virtqueue_kick(struct virtqueue *vq);
      62                 :            : 
      63                 :            : bool virtqueue_kick_prepare(struct virtqueue *vq);
      64                 :            : 
      65                 :            : bool virtqueue_notify(struct virtqueue *vq);
      66                 :            : 
      67                 :            : void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
      68                 :            : 
      69                 :            : void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
      70                 :            :                             void **ctx);
      71                 :            : 
      72                 :            : void virtqueue_disable_cb(struct virtqueue *vq);
      73                 :            : 
      74                 :            : bool virtqueue_enable_cb(struct virtqueue *vq);
      75                 :            : 
      76                 :            : unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
      77                 :            : 
      78                 :            : bool virtqueue_poll(struct virtqueue *vq, unsigned);
      79                 :            : 
      80                 :            : bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
      81                 :            : 
      82                 :            : void *virtqueue_detach_unused_buf(struct virtqueue *vq);
      83                 :            : 
      84                 :            : unsigned int virtqueue_get_vring_size(struct virtqueue *vq);
      85                 :            : 
      86                 :            : bool virtqueue_is_broken(struct virtqueue *vq);
      87                 :            : 
      88                 :            : const struct vring *virtqueue_get_vring(struct virtqueue *vq);
      89                 :            : dma_addr_t virtqueue_get_desc_addr(struct virtqueue *vq);
      90                 :            : dma_addr_t virtqueue_get_avail_addr(struct virtqueue *vq);
      91                 :            : dma_addr_t virtqueue_get_used_addr(struct virtqueue *vq);
      92                 :            : 
      93                 :            : /**
      94                 :            :  * virtio_device - representation of a device using virtio
      95                 :            :  * @index: unique position on the virtio bus
      96                 :            :  * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
      97                 :            :  * @config_enabled: configuration change reporting enabled
      98                 :            :  * @config_change_pending: configuration change reported while disabled
      99                 :            :  * @config_lock: protects configuration change reporting
     100                 :            :  * @dev: underlying device.
     101                 :            :  * @id: the device type identification (used to match it with a driver).
     102                 :            :  * @config: the configuration ops for this device.
     103                 :            :  * @vringh_config: configuration ops for host vrings.
     104                 :            :  * @vqs: the list of virtqueues for this device.
     105                 :            :  * @features: the features supported by both driver and device.
     106                 :            :  * @priv: private pointer for the driver's use.
     107                 :            :  */
     108                 :            : struct virtio_device {
     109                 :            :         int index;
     110                 :            :         bool failed;
     111                 :            :         bool config_enabled;
     112                 :            :         bool config_change_pending;
     113                 :            :         spinlock_t config_lock;
     114                 :            :         struct device dev;
     115                 :            :         struct virtio_device_id id;
     116                 :            :         const struct virtio_config_ops *config;
     117                 :            :         const struct vringh_config_ops *vringh_config;
     118                 :            :         struct list_head vqs;
     119                 :            :         u64 features;
     120                 :            :         void *priv;
     121                 :            : };
     122                 :            : 
     123                 :          0 : static inline struct virtio_device *dev_to_virtio(struct device *_dev)
     124                 :            : {
     125                 :          0 :         return container_of(_dev, struct virtio_device, dev);
     126                 :            : }
     127                 :            : 
     128                 :            : void virtio_add_status(struct virtio_device *dev, unsigned int status);
     129                 :            : int register_virtio_device(struct virtio_device *dev);
     130                 :            : void unregister_virtio_device(struct virtio_device *dev);
     131                 :            : 
     132                 :            : void virtio_break_device(struct virtio_device *dev);
     133                 :            : 
     134                 :            : void virtio_config_changed(struct virtio_device *dev);
     135                 :            : void virtio_config_disable(struct virtio_device *dev);
     136                 :            : void virtio_config_enable(struct virtio_device *dev);
     137                 :            : int virtio_finalize_features(struct virtio_device *dev);
     138                 :            : #ifdef CONFIG_PM_SLEEP
     139                 :            : int virtio_device_freeze(struct virtio_device *dev);
     140                 :            : int virtio_device_restore(struct virtio_device *dev);
     141                 :            : #endif
     142                 :            : 
     143                 :            : size_t virtio_max_dma_size(struct virtio_device *vdev);
     144                 :            : 
     145                 :            : #define virtio_device_for_each_vq(vdev, vq) \
     146                 :            :         list_for_each_entry(vq, &vdev->vqs, list)
     147                 :            : 
     148                 :            : /**
     149                 :            :  * virtio_driver - operations for a virtio I/O driver
     150                 :            :  * @driver: underlying device driver (populate name and owner).
     151                 :            :  * @id_table: the ids serviced by this driver.
     152                 :            :  * @feature_table: an array of feature numbers supported by this driver.
     153                 :            :  * @feature_table_size: number of entries in the feature table array.
     154                 :            :  * @feature_table_legacy: same as feature_table but when working in legacy mode.
     155                 :            :  * @feature_table_size_legacy: number of entries in feature table legacy array.
     156                 :            :  * @probe: the function to call when a device is found.  Returns 0 or -errno.
     157                 :            :  * @scan: optional function to call after successful probe; intended
     158                 :            :  *    for virtio-scsi to invoke a scan.
     159                 :            :  * @remove: the function to call when a device is removed.
     160                 :            :  * @config_changed: optional function to call when the device configuration
     161                 :            :  *    changes; may be called in interrupt context.
     162                 :            :  * @freeze: optional function to call during suspend/hibernation.
     163                 :            :  * @restore: optional function to call on resume.
     164                 :            :  */
     165                 :            : struct virtio_driver {
     166                 :            :         struct device_driver driver;
     167                 :            :         const struct virtio_device_id *id_table;
     168                 :            :         const unsigned int *feature_table;
     169                 :            :         unsigned int feature_table_size;
     170                 :            :         const unsigned int *feature_table_legacy;
     171                 :            :         unsigned int feature_table_size_legacy;
     172                 :            :         int (*validate)(struct virtio_device *dev);
     173                 :            :         int (*probe)(struct virtio_device *dev);
     174                 :            :         void (*scan)(struct virtio_device *dev);
     175                 :            :         void (*remove)(struct virtio_device *dev);
     176                 :            :         void (*config_changed)(struct virtio_device *dev);
     177                 :            : #ifdef CONFIG_PM
     178                 :            :         int (*freeze)(struct virtio_device *dev);
     179                 :            :         int (*restore)(struct virtio_device *dev);
     180                 :            : #endif
     181                 :            : };
     182                 :            : 
     183                 :          0 : static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
     184                 :            : {
     185   [ #  #  #  # ]:          0 :         return container_of(drv, struct virtio_driver, driver);
     186                 :            : }
     187                 :            : 
     188                 :            : int register_virtio_driver(struct virtio_driver *drv);
     189                 :            : void unregister_virtio_driver(struct virtio_driver *drv);
     190                 :            : 
     191                 :            : /* module_virtio_driver() - Helper macro for drivers that don't do
     192                 :            :  * anything special in module init/exit.  This eliminates a lot of
     193                 :            :  * boilerplate.  Each module may only use this macro once, and
     194                 :            :  * calling it replaces module_init() and module_exit()
     195                 :            :  */
     196                 :            : #define module_virtio_driver(__virtio_driver) \
     197                 :            :         module_driver(__virtio_driver, register_virtio_driver, \
     198                 :            :                         unregister_virtio_driver)
     199                 :            : #endif /* _LINUX_VIRTIO_H */