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 int ret; 124 }; 125 126 /** 127 * struct virtio_device - representation of a device using virtio 128 * @index: unique position on the virtio bus 129 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore) 130 * @config_core_enabled: configuration change reporting enabled by core 131 * @config_driver_disabled: configuration change reporting disabled by 132 * a driver 133 * @config_change_pending: configuration change reported while disabled 134 * @config_lock: protects configuration change reporting 135 * @vqs_list_lock: protects @vqs. 136 * @dev: underlying device. 137 * @id: the device type identification (used to match it with a driver). 138 * @config: the configuration ops for this device. 139 * @vringh_config: configuration ops for host vrings. 140 * @vqs: the list of virtqueues for this device. 141 * @features: the features supported by both driver and device. 142 * @priv: private pointer for the driver's use. 143 * @debugfs_dir: debugfs directory entry. 144 * @debugfs_filter_features: features to be filtered set by debugfs. 145 */ 146 struct virtio_device { 147 int index; 148 bool failed; 149 bool config_core_enabled; 150 bool config_driver_disabled; 151 bool config_change_pending; 152 spinlock_t config_lock; 153 spinlock_t vqs_list_lock; 154 struct device dev; 155 struct virtio_device_id id; 156 const struct virtio_config_ops *config; 157 const struct vringh_config_ops *vringh_config; 158 struct list_head vqs; 159 u64 features; 160 void *priv; 161 #ifdef CONFIG_VIRTIO_DEBUG 162 struct dentry *debugfs_dir; 163 u64 debugfs_filter_features; 164 #endif 165 }; 166 167 #define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev) 168 169 void virtio_add_status(struct virtio_device *dev, unsigned int status); 170 int register_virtio_device(struct virtio_device *dev); 171 void unregister_virtio_device(struct virtio_device *dev); 172 bool is_virtio_device(struct device *dev); 173 174 void virtio_break_device(struct virtio_device *dev); 175 void __virtio_unbreak_device(struct virtio_device *dev); 176 177 void __virtqueue_break(struct virtqueue *_vq); 178 void __virtqueue_unbreak(struct virtqueue *_vq); 179 180 void virtio_config_changed(struct virtio_device *dev); 181 182 void virtio_config_driver_disable(struct virtio_device *dev); 183 void virtio_config_driver_enable(struct virtio_device *dev); 184 185 #ifdef CONFIG_PM_SLEEP 186 int virtio_device_freeze(struct virtio_device *dev); 187 int virtio_device_restore(struct virtio_device *dev); 188 #endif 189 void virtio_reset_device(struct virtio_device *dev); 190 191 size_t virtio_max_dma_size(const struct virtio_device *vdev); 192 193 #define virtio_device_for_each_vq(vdev, vq) \ 194 list_for_each_entry(vq, &vdev->vqs, list) 195 196 /** 197 * struct virtio_driver - operations for a virtio I/O driver 198 * @driver: underlying device driver (populate name). 199 * @id_table: the ids serviced by this driver. 200 * @feature_table: an array of feature numbers supported by this driver. 201 * @feature_table_size: number of entries in the feature table array. 202 * @feature_table_legacy: same as feature_table but when working in legacy mode. 203 * @feature_table_size_legacy: number of entries in feature table legacy array. 204 * @validate: the function to call to validate features and config space. 205 * Returns 0 or -errno. 206 * @probe: the function to call when a device is found. Returns 0 or -errno. 207 * @scan: optional function to call after successful probe; intended 208 * for virtio-scsi to invoke a scan. 209 * @remove: the function to call when a device is removed. 210 * @config_changed: optional function to call when the device configuration 211 * changes; may be called in interrupt context. 212 * @freeze: optional function to call during suspend/hibernation. 213 * @restore: optional function to call on resume. 214 */ 215 struct virtio_driver { 216 struct device_driver driver; 217 const struct virtio_device_id *id_table; 218 const unsigned int *feature_table; 219 unsigned int feature_table_size; 220 const unsigned int *feature_table_legacy; 221 unsigned int feature_table_size_legacy; 222 int (*validate)(struct virtio_device *dev); 223 int (*probe)(struct virtio_device *dev); 224 void (*scan)(struct virtio_device *dev); 225 void (*remove)(struct virtio_device *dev); 226 void (*config_changed)(struct virtio_device *dev); 227 int (*freeze)(struct virtio_device *dev); 228 int (*restore)(struct virtio_device *dev); 229 }; 230 231 #define drv_to_virtio(__drv) container_of_const(__drv, struct virtio_driver, driver) 232 233 /* use a macro to avoid include chaining to get THIS_MODULE */ 234 #define register_virtio_driver(drv) \ 235 __register_virtio_driver(drv, THIS_MODULE) 236 int __register_virtio_driver(struct virtio_driver *drv, struct module *owner); 237 void unregister_virtio_driver(struct virtio_driver *drv); 238 239 /* module_virtio_driver() - Helper macro for drivers that don't do 240 * anything special in module init/exit. This eliminates a lot of 241 * boilerplate. Each module may only use this macro once, and 242 * calling it replaces module_init() and module_exit() 243 */ 244 #define module_virtio_driver(__virtio_driver) \ 245 module_driver(__virtio_driver, register_virtio_driver, \ 246 unregister_virtio_driver) 247 248 dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr, size_t size, 249 enum dma_data_direction dir, unsigned long attrs); 250 void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr, 251 size_t size, enum dma_data_direction dir, 252 unsigned long attrs); 253 int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr); 254 255 bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr); 256 void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, dma_addr_t addr, 257 unsigned long offset, size_t size, 258 enum dma_data_direction dir); 259 void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr, 260 unsigned long offset, size_t size, 261 enum dma_data_direction dir); 262 263 #ifdef CONFIG_VIRTIO_DEBUG 264 void virtio_debug_device_init(struct virtio_device *dev); 265 void virtio_debug_device_exit(struct virtio_device *dev); 266 void virtio_debug_device_filter_features(struct virtio_device *dev); 267 void virtio_debug_init(void); 268 void virtio_debug_exit(void); 269 #else 270 static inline void virtio_debug_device_init(struct virtio_device *dev) 271 { 272 } 273 274 static inline void virtio_debug_device_exit(struct virtio_device *dev) 275 { 276 } 277 278 static inline void virtio_debug_device_filter_features(struct virtio_device *dev) 279 { 280 } 281 282 static inline void virtio_debug_init(void) 283 { 284 } 285 286 static inline void virtio_debug_exit(void) 287 { 288 } 289 #endif 290 291 #endif /* _LINUX_VIRTIO_H */ 292