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 */ 293