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 #include <linux/virtio_features.h> 15 16 /** 17 * struct virtqueue - a queue to register buffers for sending or receiving. 18 * @list: the chain of virtqueues for this device 19 * @callback: the function to call when buffers are consumed (can be NULL). 20 * @name: the name of this virtqueue (mainly for debugging) 21 * @vdev: the virtio device this queue was created for. 22 * @priv: a pointer for the virtqueue implementation to use. 23 * @index: the zero-based ordinal number for this queue. 24 * @num_free: number of elements we expect to be able to fit. 25 * @num_max: the maximum number of elements supported by the device. 26 * @reset: vq is in reset state or not. 27 * 28 * A note on @num_free: with indirect buffers, each buffer needs one 29 * element in the queue, otherwise a buffer will need one element per 30 * sg element. 31 */ 32 struct virtqueue { 33 struct list_head list; 34 void (*callback)(struct virtqueue *vq); 35 const char *name; 36 struct virtio_device *vdev; 37 unsigned int index; 38 unsigned int num_free; 39 unsigned int num_max; 40 bool reset; 41 void *priv; 42 }; 43 44 struct vduse_iova_domain; 45 46 union virtio_map { 47 /* Device that performs DMA */ 48 struct device *dma_dev; 49 /* VDUSE specific mapping data */ 50 struct vduse_iova_domain *iova_domain; 51 }; 52 53 int virtqueue_add_outbuf(struct virtqueue *vq, 54 struct scatterlist sg[], unsigned int num, 55 void *data, 56 gfp_t gfp); 57 58 int virtqueue_add_inbuf(struct virtqueue *vq, 59 struct scatterlist sg[], unsigned int num, 60 void *data, 61 gfp_t gfp); 62 63 int virtqueue_add_inbuf_ctx(struct virtqueue *vq, 64 struct scatterlist sg[], unsigned int num, 65 void *data, 66 void *ctx, 67 gfp_t gfp); 68 69 int virtqueue_add_inbuf_premapped(struct virtqueue *vq, 70 struct scatterlist *sg, unsigned int num, 71 void *data, 72 void *ctx, 73 gfp_t gfp); 74 75 int virtqueue_add_outbuf_premapped(struct virtqueue *vq, 76 struct scatterlist *sg, unsigned int num, 77 void *data, 78 gfp_t gfp); 79 80 int virtqueue_add_sgs(struct virtqueue *vq, 81 struct scatterlist *sgs[], 82 unsigned int out_sgs, 83 unsigned int in_sgs, 84 void *data, 85 gfp_t gfp); 86 87 struct device *virtqueue_dma_dev(struct virtqueue *vq); 88 89 bool virtqueue_kick(struct virtqueue *vq); 90 91 bool virtqueue_kick_prepare(struct virtqueue *vq); 92 93 bool virtqueue_notify(struct virtqueue *vq); 94 95 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); 96 97 void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len, 98 void **ctx); 99 100 void virtqueue_disable_cb(struct virtqueue *vq); 101 102 bool virtqueue_enable_cb(struct virtqueue *vq); 103 104 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq); 105 106 bool virtqueue_poll(struct virtqueue *vq, unsigned); 107 108 bool virtqueue_enable_cb_delayed(struct virtqueue *vq); 109 110 void *virtqueue_detach_unused_buf(struct virtqueue *vq); 111 112 unsigned int virtqueue_get_vring_size(const struct virtqueue *vq); 113 114 bool virtqueue_is_broken(const struct virtqueue *vq); 115 116 const struct vring *virtqueue_get_vring(const struct virtqueue *vq); 117 dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq); 118 dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq); 119 dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq); 120 121 int virtqueue_resize(struct virtqueue *vq, u32 num, 122 void (*recycle)(struct virtqueue *vq, void *buf), 123 void (*recycle_done)(struct virtqueue *vq)); 124 int virtqueue_reset(struct virtqueue *vq, 125 void (*recycle)(struct virtqueue *vq, void *buf), 126 void (*recycle_done)(struct virtqueue *vq)); 127 128 struct virtio_admin_cmd { 129 __le16 opcode; 130 __le16 group_type; 131 __le64 group_member_id; 132 struct scatterlist *data_sg; 133 struct scatterlist *result_sg; 134 struct completion completion; 135 u32 result_sg_size; 136 int ret; 137 }; 138 139 /** 140 * struct virtio_device - representation of a device using virtio 141 * @index: unique position on the virtio bus 142 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore) 143 * @config_core_enabled: configuration change reporting enabled by core 144 * @config_driver_disabled: configuration change reporting disabled by 145 * a driver 146 * @config_change_pending: configuration change reported while disabled 147 * @config_lock: protects configuration change reporting 148 * @vqs_list_lock: protects @vqs. 149 * @dev: underlying device. 150 * @id: the device type identification (used to match it with a driver). 151 * @config: the configuration ops for this device. 152 * @vringh_config: configuration ops for host vrings. 153 * @vqs: the list of virtqueues for this device. 154 * @features: the 64 lower features supported by both driver and device. 155 * @features_array: the full features space supported by both driver and 156 * device. 157 * @priv: private pointer for the driver's use. 158 * @debugfs_dir: debugfs directory entry. 159 * @debugfs_filter_features: features to be filtered set by debugfs. 160 */ 161 struct virtio_device { 162 int index; 163 bool failed; 164 bool config_core_enabled; 165 bool config_driver_disabled; 166 bool config_change_pending; 167 spinlock_t config_lock; 168 spinlock_t vqs_list_lock; 169 struct device dev; 170 struct virtio_device_id id; 171 const struct virtio_config_ops *config; 172 const struct vringh_config_ops *vringh_config; 173 const struct virtio_map_ops *map; 174 struct list_head vqs; 175 VIRTIO_DECLARE_FEATURES(features); 176 void *priv; 177 union virtio_map vmap; 178 #ifdef CONFIG_VIRTIO_DEBUG 179 struct dentry *debugfs_dir; 180 u64 debugfs_filter_features[VIRTIO_FEATURES_DWORDS]; 181 #endif 182 }; 183 184 #define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev) 185 186 void virtio_add_status(struct virtio_device *dev, unsigned int status); 187 int register_virtio_device(struct virtio_device *dev); 188 void unregister_virtio_device(struct virtio_device *dev); 189 bool is_virtio_device(struct device *dev); 190 191 void virtio_break_device(struct virtio_device *dev); 192 void __virtio_unbreak_device(struct virtio_device *dev); 193 194 void __virtqueue_break(struct virtqueue *_vq); 195 void __virtqueue_unbreak(struct virtqueue *_vq); 196 197 void virtio_config_changed(struct virtio_device *dev); 198 199 void virtio_config_driver_disable(struct virtio_device *dev); 200 void virtio_config_driver_enable(struct virtio_device *dev); 201 202 #ifdef CONFIG_PM_SLEEP 203 int virtio_device_freeze(struct virtio_device *dev); 204 int virtio_device_restore(struct virtio_device *dev); 205 #endif 206 void virtio_reset_device(struct virtio_device *dev); 207 int virtio_device_reset_prepare(struct virtio_device *dev); 208 int virtio_device_reset_done(struct virtio_device *dev); 209 210 size_t virtio_max_dma_size(const struct virtio_device *vdev); 211 212 #define virtio_device_for_each_vq(vdev, vq) \ 213 list_for_each_entry(vq, &(vdev)->vqs, list) 214 215 /** 216 * struct virtio_driver - operations for a virtio I/O driver 217 * @driver: underlying device driver (populate name). 218 * @id_table: the ids serviced by this driver. 219 * @feature_table: an array of feature numbers supported by this driver. 220 * @feature_table_size: number of entries in the feature table array. 221 * @feature_table_legacy: same as feature_table but when working in legacy mode. 222 * @feature_table_size_legacy: number of entries in feature table legacy array. 223 * @validate: the function to call to validate features and config space. 224 * Returns 0 or -errno. 225 * @probe: the function to call when a device is found. Returns 0 or -errno. 226 * @scan: optional function to call after successful probe; intended 227 * for virtio-scsi to invoke a scan. 228 * @remove: the function to call when a device is removed. 229 * @config_changed: optional function to call when the device configuration 230 * changes; may be called in interrupt context. 231 * @freeze: optional function to call during suspend/hibernation. 232 * @restore: optional function to call on resume. 233 * @reset_prepare: optional function to call when a transport specific reset 234 * occurs. 235 * @reset_done: optional function to call after transport specific reset 236 * operation has finished. 237 * @shutdown: synchronize with the device on shutdown. If provided, replaces 238 * the virtio core implementation. 239 */ 240 struct virtio_driver { 241 struct device_driver driver; 242 const struct virtio_device_id *id_table; 243 const unsigned int *feature_table; 244 unsigned int feature_table_size; 245 const unsigned int *feature_table_legacy; 246 unsigned int feature_table_size_legacy; 247 int (*validate)(struct virtio_device *dev); 248 int (*probe)(struct virtio_device *dev); 249 void (*scan)(struct virtio_device *dev); 250 void (*remove)(struct virtio_device *dev); 251 void (*config_changed)(struct virtio_device *dev); 252 int (*freeze)(struct virtio_device *dev); 253 int (*restore)(struct virtio_device *dev); 254 int (*reset_prepare)(struct virtio_device *dev); 255 int (*reset_done)(struct virtio_device *dev); 256 void (*shutdown)(struct virtio_device *dev); 257 }; 258 259 #define drv_to_virtio(__drv) container_of_const(__drv, struct virtio_driver, driver) 260 261 /* use a macro to avoid include chaining to get THIS_MODULE */ 262 #define register_virtio_driver(drv) \ 263 __register_virtio_driver(drv, THIS_MODULE) 264 int __register_virtio_driver(struct virtio_driver *drv, struct module *owner); 265 void unregister_virtio_driver(struct virtio_driver *drv); 266 267 /* module_virtio_driver() - Helper macro for drivers that don't do 268 * anything special in module init/exit. This eliminates a lot of 269 * boilerplate. Each module may only use this macro once, and 270 * calling it replaces module_init() and module_exit() 271 */ 272 #define module_virtio_driver(__virtio_driver) \ 273 module_driver(__virtio_driver, register_virtio_driver, \ 274 unregister_virtio_driver) 275 276 277 void *virtqueue_map_alloc_coherent(struct virtio_device *vdev, 278 union virtio_map mapping_token, 279 size_t size, dma_addr_t *dma_handle, 280 gfp_t gfp); 281 282 void virtqueue_map_free_coherent(struct virtio_device *vdev, 283 union virtio_map mapping_token, 284 size_t size, void *vaddr, 285 dma_addr_t dma_handle); 286 287 dma_addr_t virtqueue_map_page_attrs(const struct virtqueue *_vq, 288 struct page *page, 289 unsigned long offset, 290 size_t size, 291 enum dma_data_direction dir, 292 unsigned long attrs); 293 294 void virtqueue_unmap_page_attrs(const struct virtqueue *_vq, 295 dma_addr_t dma_handle, 296 size_t size, enum dma_data_direction dir, 297 unsigned long attrs); 298 299 dma_addr_t virtqueue_map_single_attrs(const struct virtqueue *_vq, void *ptr, size_t size, 300 enum dma_data_direction dir, unsigned long attrs); 301 void virtqueue_unmap_single_attrs(const struct virtqueue *_vq, dma_addr_t addr, 302 size_t size, enum dma_data_direction dir, 303 unsigned long attrs); 304 int virtqueue_map_mapping_error(const struct virtqueue *_vq, dma_addr_t addr); 305 306 bool virtqueue_map_need_sync(const struct virtqueue *_vq, dma_addr_t addr); 307 void virtqueue_map_sync_single_range_for_cpu(const struct virtqueue *_vq, dma_addr_t addr, 308 unsigned long offset, size_t size, 309 enum dma_data_direction dir); 310 void virtqueue_map_sync_single_range_for_device(const struct virtqueue *_vq, dma_addr_t addr, 311 unsigned long offset, size_t size, 312 enum dma_data_direction dir); 313 314 #ifdef CONFIG_VIRTIO_DEBUG 315 void virtio_debug_device_init(struct virtio_device *dev); 316 void virtio_debug_device_exit(struct virtio_device *dev); 317 void virtio_debug_device_filter_features(struct virtio_device *dev); 318 void virtio_debug_init(void); 319 void virtio_debug_exit(void); 320 #else 321 static inline void virtio_debug_device_init(struct virtio_device *dev) 322 { 323 } 324 325 static inline void virtio_debug_device_exit(struct virtio_device *dev) 326 { 327 } 328 329 static inline void virtio_debug_device_filter_features(struct virtio_device *dev) 330 { 331 } 332 333 static inline void virtio_debug_init(void) 334 { 335 } 336 337 static inline void virtio_debug_exit(void) 338 { 339 } 340 #endif 341 342 #endif /* _LINUX_VIRTIO_H */ 343