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