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