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 #include <linux/dma-mapping.h>
  13 #include <linux/completion.h>
  14
  15 /**
  16  * struct virtqueue - a queue to register buffers for sending or receiving.
  17  * @list: the chain of virtqueues for this device
  18  * @callback: the function to call when buffers are consumed (can be NULL).
  19  * @name: the name of this virtqueue (mainly for debugging)
  20  * @vdev: the virtio device this queue was created for.
  21  * @priv: a pointer for the virtqueue implementation to use.
  22  * @index: the zero-based ordinal number for this queue.
  23  * @num_free: number of elements we expect to be able to fit.
  24  * @num_max: the maximum number of elements supported by the device.
  25  * @reset: vq is in reset state or not.
  26  *
  27  * A note on @num_free: with indirect buffers, each buffer needs one
  28  * element in the queue, otherwise a buffer will need one element per
  29  * sg element.
  30  */
  31 struct virtqueue {
  32         struct list_head list;
  33         void (*callback)(struct virtqueue *vq);
  34         const char *name;
  35         struct virtio_device *vdev;
  36         unsigned int index;
  37         unsigned int num_free;
  38         unsigned int num_max;
  39         bool reset;
  40         void *priv;
  41 };
  42
  43 int virtqueue_add_outbuf(struct virtqueue *vq,
  44                          struct scatterlist sg[], unsigned int num,
  45                          void *data,
  46                          gfp_t gfp);
  47
  48 int virtqueue_add_inbuf(struct virtqueue *vq,
  49                         struct scatterlist sg[], unsigned int num,
  50                         void *data,
  51                         gfp_t gfp);
  52
  53 int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
  54                             struct scatterlist sg[], unsigned int num,
  55                             void *data,
  56                             void *ctx,
  57                             gfp_t gfp);
  58
  59 int virtqueue_add_inbuf_premapped(struct virtqueue *vq,
  60                                   struct scatterlist *sg, unsigned int num,
  61                                   void *data,
  62                                   void *ctx,
  63                                   gfp_t gfp);
  64
  65 int virtqueue_add_outbuf_premapped(struct virtqueue *vq,
  66                                    struct scatterlist *sg, unsigned int num,
  67                                    void *data,
  68                                    gfp_t gfp);
  69
  70 int virtqueue_add_sgs(struct virtqueue *vq,
  71                       struct scatterlist *sgs[],
  72                       unsigned int out_sgs,
  73                       unsigned int in_sgs,
  74                       void *data,
  75                       gfp_t gfp);
  76
  77 struct device *virtqueue_dma_dev(struct virtqueue *vq);
  78
  79 bool virtqueue_kick(struct virtqueue *vq);
  80
  81 bool virtqueue_kick_prepare(struct virtqueue *vq);
  82
  83 bool virtqueue_notify(struct virtqueue *vq);
  84
  85 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
  86
  87 void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
  88                             void **ctx);
  89
  90 void virtqueue_disable_cb(struct virtqueue *vq);
  91
  92 bool virtqueue_enable_cb(struct virtqueue *vq);
  93
  94 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
  95
  96 bool virtqueue_poll(struct virtqueue *vq, unsigned);
  97
  98 bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
  99
 100 void *virtqueue_detach_unused_buf(struct virtqueue *vq);
 101
 102 unsigned int virtqueue_get_vring_size(const struct virtqueue *vq);
 103
 104 bool virtqueue_is_broken(const struct virtqueue *vq);
 105
 106 const struct vring *virtqueue_get_vring(const struct virtqueue *vq);
 107 dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq);
 108 dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq);
 109 dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq);
 110
 111 int virtqueue_resize(struct virtqueue *vq, u32 num,
 112                      void (*recycle)(struct virtqueue *vq, void *buf));
 113 int virtqueue_reset(struct virtqueue *vq,
 114                     void (*recycle)(struct virtqueue *vq, void *buf));
 115
 116 struct virtio_admin_cmd {
 117         __le16 opcode;
 118         __le16 group_type;
 119         __le64 group_member_id;
 120         struct scatterlist *data_sg;
 121         struct scatterlist *result_sg;
 122         struct completion completion;
 123         u32 result_sg_size;
 124         int ret;
 125 };
 126
 127 /**
 128  * struct virtio_device - representation of a device using virtio
 129  * @index: unique position on the virtio bus
 130  * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
 131  * @config_core_enabled: configuration change reporting enabled by core
 132  * @config_driver_disabled: configuration change reporting disabled by
 133  *                          a driver
 134  * @config_change_pending: configuration change reported while disabled
 135  * @config_lock: protects configuration change reporting
 136  * @vqs_list_lock: protects @vqs.
 137  * @dev: underlying device.
 138  * @id: the device type identification (used to match it with a driver).
 139  * @config: the configuration ops for this device.
 140  * @vringh_config: configuration ops for host vrings.
 141  * @vqs: the list of virtqueues for this device.
 142  * @features: the features supported by both driver and device.
 143  * @priv: private pointer for the driver's use.
 144  * @debugfs_dir: debugfs directory entry.
 145  * @debugfs_filter_features: features to be filtered set by debugfs.
 146  */
 147 struct virtio_device {
 148         int index;
 149         bool failed;
 150         bool config_core_enabled;
 151         bool config_driver_disabled;
 152         bool config_change_pending;
 153         spinlock_t config_lock;
 154         spinlock_t vqs_list_lock;
 155         struct device dev;
 156         struct virtio_device_id id;
 157         const struct virtio_config_ops *config;
 158         const struct vringh_config_ops *vringh_config;
 159         struct list_head vqs;
 160         u64 features;
 161         void *priv;
 162 #ifdef CONFIG_VIRTIO_DEBUG
 163         struct dentry *debugfs_dir;
 164         u64 debugfs_filter_features;
 165 #endif
 166 };
 167
 168 #define dev_to_virtio(_dev)     container_of_const(_dev, struct virtio_device, dev)
 169
 170 void virtio_add_status(struct virtio_device *dev, unsigned int status);
 171 int register_virtio_device(struct virtio_device *dev);
 172 void unregister_virtio_device(struct virtio_device *dev);
 173 bool is_virtio_device(struct device *dev);
 174
 175 void virtio_break_device(struct virtio_device *dev);
 176 void __virtio_unbreak_device(struct virtio_device *dev);
 177
 178 void __virtqueue_break(struct virtqueue *_vq);
 179 void __virtqueue_unbreak(struct virtqueue *_vq);
 180
 181 void virtio_config_changed(struct virtio_device *dev);
 182
 183 void virtio_config_driver_disable(struct virtio_device *dev);
 184 void virtio_config_driver_enable(struct virtio_device *dev);
 185
 186 #ifdef CONFIG_PM_SLEEP
 187 int virtio_device_freeze(struct virtio_device *dev);
 188 int virtio_device_restore(struct virtio_device *dev);
 189 #endif
 190 void virtio_reset_device(struct virtio_device *dev);
 191
 192 size_t virtio_max_dma_size(const struct virtio_device *vdev);
 193
 194 #define virtio_device_for_each_vq(vdev, vq) \
 195         list_for_each_entry(vq, &vdev->vqs, list)
 196
 197 /**
 198  * struct virtio_driver - operations for a virtio I/O driver
 199  * @driver: underlying device driver (populate name).
 200  * @id_table: the ids serviced by this driver.
 201  * @feature_table: an array of feature numbers supported by this driver.
 202  * @feature_table_size: number of entries in the feature table array.
 203  * @feature_table_legacy: same as feature_table but when working in legacy mode.
 204  * @feature_table_size_legacy: number of entries in feature table legacy array.
 205  * @validate: the function to call to validate features and config space.
 206  *            Returns 0 or -errno.
 207  * @probe: the function to call when a device is found.  Returns 0 or -errno.
 208  * @scan: optional function to call after successful probe; intended
 209  *    for virtio-scsi to invoke a scan.
 210  * @remove: the function to call when a device is removed.
 211  * @config_changed: optional function to call when the device configuration
 212  *    changes; may be called in interrupt context.
 213  * @freeze: optional function to call during suspend/hibernation.
 214  * @restore: optional function to call on resume.
 215  */
 216 struct virtio_driver {
 217         struct device_driver driver;
 218         const struct virtio_device_id *id_table;
 219         const unsigned int *feature_table;
 220         unsigned int feature_table_size;
 221         const unsigned int *feature_table_legacy;
 222         unsigned int feature_table_size_legacy;
 223         int (*validate)(struct virtio_device *dev);
 224         int (*probe)(struct virtio_device *dev);
 225         void (*scan)(struct virtio_device *dev);
 226         void (*remove)(struct virtio_device *dev);
 227         void (*config_changed)(struct virtio_device *dev);
 228         int (*freeze)(struct virtio_device *dev);
 229         int (*restore)(struct virtio_device *dev);
 230 };
 231
 232 #define drv_to_virtio(__drv)    container_of_const(__drv, struct virtio_driver, driver)
 233
 234 /* use a macro to avoid include chaining to get THIS_MODULE */
 235 #define register_virtio_driver(drv) \
 236         __register_virtio_driver(drv, THIS_MODULE)
 237 int __register_virtio_driver(struct virtio_driver *drv, struct module *owner);
 238 void unregister_virtio_driver(struct virtio_driver *drv);
 239
 240 /* module_virtio_driver() - Helper macro for drivers that don't do
 241  * anything special in module init/exit.  This eliminates a lot of
 242  * boilerplate.  Each module may only use this macro once, and
 243  * calling it replaces module_init() and module_exit()
 244  */
 245 #define module_virtio_driver(__virtio_driver) \
 246         module_driver(__virtio_driver, register_virtio_driver, \
 247                         unregister_virtio_driver)
 248
 249 dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr, size_t size,
 250                                           enum dma_data_direction dir, unsigned long attrs);
 251 void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr,
 252                                       size_t size, enum dma_data_direction dir,
 253                                       unsigned long attrs);
 254 int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr);
 255
 256 bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr);
 257 void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, dma_addr_t addr,
 258                                              unsigned long offset, size_t size,
 259                                              enum dma_data_direction dir);
 260 void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr,
 261                                                 unsigned long offset, size_t size,
 262                                                 enum dma_data_direction dir);
 263
 264 #ifdef CONFIG_VIRTIO_DEBUG
 265 void virtio_debug_device_init(struct virtio_device *dev);
 266 void virtio_debug_device_exit(struct virtio_device *dev);
 267 void virtio_debug_device_filter_features(struct virtio_device *dev);
 268 void virtio_debug_init(void);
 269 void virtio_debug_exit(void);
 270 #else
 271 static inline void virtio_debug_device_init(struct virtio_device *dev)
 272 {
 273 }
 274
 275 static inline void virtio_debug_device_exit(struct virtio_device *dev)
 276 {
 277 }
 278
 279 static inline void virtio_debug_device_filter_features(struct virtio_device *dev)
 280 {
 281 }
 282
 283 static inline void virtio_debug_init(void)
 284 {
 285 }
 286
 287 static inline void virtio_debug_exit(void)
 288 {
 289 }
 290 #endif
 291
 292 #endif /* _LINUX_VIRTIO_H */