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 /** 107 * struct virtio_device - representation of a device using virtio 108 * @index: unique position on the virtio bus 109 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore) 110 * @config_enabled: configuration change reporting enabled 111 * @config_change_pending: configuration change reported while disabled 112 * @config_lock: protects configuration change reporting 113 * @vqs_list_lock: protects @vqs. 114 * @dev: underlying device. 115 * @id: the device type identification (used to match it with a driver). 116 * @config: the configuration ops for this device. 117 * @vringh_config: configuration ops for host vrings. 118 * @vqs: the list of virtqueues for this device. 119 * @features: the features supported by both driver and device. 120 * @priv: private pointer for the driver's use. 121 */ 122 struct virtio_device { 123 int index; 124 bool failed; 125 bool config_enabled; 126 bool config_change_pending; 127 spinlock_t config_lock; 128 spinlock_t vqs_list_lock; 129 struct device dev; 130 struct virtio_device_id id; 131 const struct virtio_config_ops *config; 132 const struct vringh_config_ops *vringh_config; 133 struct list_head vqs; 134 u64 features; 135 void *priv; 136 }; 137 138 #define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev) 139 140 void virtio_add_status(struct virtio_device *dev, unsigned int status); 141 int register_virtio_device(struct virtio_device *dev); 142 void unregister_virtio_device(struct virtio_device *dev); 143 bool is_virtio_device(struct device *dev); 144 145 void virtio_break_device(struct virtio_device *dev); 146 void __virtio_unbreak_device(struct virtio_device *dev); 147 148 void __virtqueue_break(struct virtqueue *_vq); 149 void __virtqueue_unbreak(struct virtqueue *_vq); 150 151 void virtio_config_changed(struct virtio_device *dev); 152 #ifdef CONFIG_PM_SLEEP 153 int virtio_device_freeze(struct virtio_device *dev); 154 int virtio_device_restore(struct virtio_device *dev); 155 #endif 156 void virtio_reset_device(struct virtio_device *dev); 157 158 size_t virtio_max_dma_size(const struct virtio_device *vdev); 159 160 #define virtio_device_for_each_vq(vdev, vq) \ 161 list_for_each_entry(vq, &vdev->vqs, list) 162 163 /** 164 * struct virtio_driver - operations for a virtio I/O driver 165 * @driver: underlying device driver (populate name and owner). 166 * @id_table: the ids serviced by this driver. 167 * @feature_table: an array of feature numbers supported by this driver. 168 * @feature_table_size: number of entries in the feature table array. 169 * @feature_table_legacy: same as feature_table but when working in legacy mode. 170 * @feature_table_size_legacy: number of entries in feature table legacy array. 171 * @validate: the function to call to validate features and config space. 172 * Returns 0 or -errno. 173 * @probe: the function to call when a device is found. Returns 0 or -errno. 174 * @scan: optional function to call after successful probe; intended 175 * for virtio-scsi to invoke a scan. 176 * @remove: the function to call when a device is removed. 177 * @config_changed: optional function to call when the device configuration 178 * changes; may be called in interrupt context. 179 * @freeze: optional function to call during suspend/hibernation. 180 * @restore: optional function to call on resume. 181 */ 182 struct virtio_driver { 183 struct device_driver driver; 184 const struct virtio_device_id *id_table; 185 const unsigned int *feature_table; 186 unsigned int feature_table_size; 187 const unsigned int *feature_table_legacy; 188 unsigned int feature_table_size_legacy; 189 int (*validate)(struct virtio_device *dev); 190 int (*probe)(struct virtio_device *dev); 191 void (*scan)(struct virtio_device *dev); 192 void (*remove)(struct virtio_device *dev); 193 void (*config_changed)(struct virtio_device *dev); 194 int (*freeze)(struct virtio_device *dev); 195 int (*restore)(struct virtio_device *dev); 196 }; 197 198 static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv) 199 { 200 return container_of(drv, struct virtio_driver, driver); 201 } 202 203 int register_virtio_driver(struct virtio_driver *drv); 204 void unregister_virtio_driver(struct virtio_driver *drv); 205 206 /* module_virtio_driver() - Helper macro for drivers that don't do 207 * anything special in module init/exit. This eliminates a lot of 208 * boilerplate. Each module may only use this macro once, and 209 * calling it replaces module_init() and module_exit() 210 */ 211 #define module_virtio_driver(__virtio_driver) \ 212 module_driver(__virtio_driver, register_virtio_driver, \ 213 unregister_virtio_driver) 214 215 dma_addr_t virtqueue_dma_map_single_attrs(struct virtqueue *_vq, void *ptr, size_t size, 216 enum dma_data_direction dir, unsigned long attrs); 217 void virtqueue_dma_unmap_single_attrs(struct virtqueue *_vq, dma_addr_t addr, 218 size_t size, enum dma_data_direction dir, 219 unsigned long attrs); 220 int virtqueue_dma_mapping_error(struct virtqueue *_vq, dma_addr_t addr); 221 222 bool virtqueue_dma_need_sync(struct virtqueue *_vq, dma_addr_t addr); 223 void virtqueue_dma_sync_single_range_for_cpu(struct virtqueue *_vq, dma_addr_t addr, 224 unsigned long offset, size_t size, 225 enum dma_data_direction dir); 226 void virtqueue_dma_sync_single_range_for_device(struct virtqueue *_vq, dma_addr_t addr, 227 unsigned long offset, size_t size, 228 enum dma_data_direction dir); 229 #endif /* _LINUX_VIRTIO_H */ 230