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 int ret; 115 }; 116 117 /** 118 * struct virtio_device - representation of a device using virtio 119 * @index: unique position on the virtio bus 120 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore) 121 * @config_enabled: configuration change reporting enabled 122 * @config_change_pending: configuration change reported while disabled 123 * @config_lock: protects configuration change reporting 124 * @vqs_list_lock: protects @vqs. 125 * @dev: underlying device. 126 * @id: the device type identification (used to match it with a driver). 127 * @config: the configuration ops for this device. 128 * @vringh_config: configuration ops for host vrings. 129 * @vqs: the list of virtqueues for this device. 130 * @features: the features supported by both driver and device. 131 * @priv: private pointer for the driver's use. 132 * @debugfs_dir: debugfs directory entry. 133 * @debugfs_filter_features: features to be filtered set by debugfs. 134 */ 135 struct virtio_device { 136 int index; 137 bool failed; 138 bool config_enabled; 139 bool config_change_pending; 140 spinlock_t config_lock; 141 spinlock_t vqs_list_lock; 142 struct device dev; 143 struct virtio_device_id id; 144 const struct virtio_config_ops *config; 145 const struct vringh_config_ops *vringh_config; 146 struct list_head vqs; 147 u64 features; 148 void *priv; 149 #ifdef CONFIG_VIRTIO_DEBUG 150 struct dentry *debugfs_dir; 151 u64 debugfs_filter_features; 152 #endif 153 }; 154 155 #define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev) 156 157 void virtio_add_status(struct virtio_device *dev, unsigned int status); 158 int register_virtio_device(struct virtio_device *dev); 159 void unregister_virtio_device(struct virtio_device *dev); 160 bool is_virtio_device(struct device *dev); 161 162 void virtio_break_device(struct virtio_device *dev); 163 void __virtio_unbreak_device(struct virtio_device *dev); 164 165 void __virtqueue_break(struct virtqueue *_vq); 166 void __virtqueue_unbreak(struct virtqueue *_vq); 167 168 void virtio_config_changed(struct virtio_device *dev); 169 #ifdef CONFIG_PM_SLEEP 170 int virtio_device_freeze(struct virtio_device *dev); 171 int virtio_device_restore(struct virtio_device *dev); 172 #endif 173 void virtio_reset_device(struct virtio_device *dev); 174 175 size_t virtio_max_dma_size(const struct virtio_device *vdev); 176 177 #define virtio_device_for_each_vq(vdev, vq) \ 178 list_for_each_entry(vq, &vdev->vqs, list) 179 180 /** 181 * struct virtio_driver - operations for a virtio I/O driver 182 * @driver: underlying device driver (populate name). 183 * @id_table: the ids serviced by this driver. 184 * @feature_table: an array of feature numbers supported by this driver. 185 * @feature_table_size: number of entries in the feature table array. 186 * @feature_table_legacy: same as feature_table but when working in legacy mode. 187 * @feature_table_size_legacy: number of entries in feature table legacy array. 188 * @validate: the function to call to validate features and config space. 189 * Returns 0 or -errno. 190 * @probe: the function to call when a device is found. Returns 0 or -errno. 191 * @scan: optional function to call after successful probe; intended 192 * for virtio-scsi to invoke a scan. 193 * @remove: the function to call when a device is removed. 194 * @config_changed: optional function to call when the device configuration 195 * changes; may be called in interrupt context. 196 * @freeze: optional function to call during suspend/hibernation. 197 * @restore: optional function to call on resume. 198 */ 199 struct virtio_driver { 200 struct device_driver driver; 201 const struct virtio_device_id *id_table; 202 const unsigned int *feature_table; 203 unsigned int feature_table_size; 204 const unsigned int *feature_table_legacy; 205 unsigned int feature_table_size_legacy; 206 int (*validate)(struct virtio_device *dev); 207 int (*probe)(struct virtio_device *dev); 208 void (*scan)(struct virtio_device *dev); 209 void (*remove)(struct virtio_device *dev); 210 void (*config_changed)(struct virtio_device *dev); 211 int (*freeze)(struct virtio_device *dev); 212 int (*restore)(struct virtio_device *dev); 213 }; 214 215 #define drv_to_virtio(__drv) container_of_const(__drv, struct virtio_driver, driver) 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