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 13 /** 14 * struct virtqueue - a queue to register buffers for sending or receiving. 15 * @list: the chain of virtqueues for this device 16 * @callback: the function to call when buffers are consumed (can be NULL). 17 * @name: the name of this virtqueue (mainly for debugging) 18 * @vdev: the virtio device this queue was created for. 19 * @priv: a pointer for the virtqueue implementation to use. 20 * @index: the zero-based ordinal number for this queue. 21 * @num_free: number of elements we expect to be able to fit. 22 * @num_max: the maximum number of elements supported by the device. 23 * @reset: vq is in reset state or not. 24 * 25 * A note on @num_free: with indirect buffers, each buffer needs one 26 * element in the queue, otherwise a buffer will need one element per 27 * sg element. 28 */ 29 struct virtqueue { 30 struct list_head list; 31 void (*callback)(struct virtqueue *vq); 32 const char *name; 33 struct virtio_device *vdev; 34 unsigned int index; 35 unsigned int num_free; 36 unsigned int num_max; 37 bool reset; 38 void *priv; 39 }; 40 41 int virtqueue_add_outbuf(struct virtqueue *vq, 42 struct scatterlist sg[], unsigned int num, 43 void *data, 44 gfp_t gfp); 45 46 int virtqueue_add_inbuf(struct virtqueue *vq, 47 struct scatterlist sg[], unsigned int num, 48 void *data, 49 gfp_t gfp); 50 51 int virtqueue_add_inbuf_ctx(struct virtqueue *vq, 52 struct scatterlist sg[], unsigned int num, 53 void *data, 54 void *ctx, 55 gfp_t gfp); 56 57 int virtqueue_add_sgs(struct virtqueue *vq, 58 struct scatterlist *sgs[], 59 unsigned int out_sgs, 60 unsigned int in_sgs, 61 void *data, 62 gfp_t gfp); 63 64 struct device *virtqueue_dma_dev(struct virtqueue *vq); 65 66 bool virtqueue_kick(struct virtqueue *vq); 67 68 bool virtqueue_kick_prepare(struct virtqueue *vq); 69 70 bool virtqueue_notify(struct virtqueue *vq); 71 72 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); 73 74 void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len, 75 void **ctx); 76 77 void virtqueue_disable_cb(struct virtqueue *vq); 78 79 bool virtqueue_enable_cb(struct virtqueue *vq); 80 81 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq); 82 83 int virtqueue_set_dma_premapped(struct virtqueue *_vq); 84 85 bool virtqueue_poll(struct virtqueue *vq, unsigned); 86 87 bool virtqueue_enable_cb_delayed(struct virtqueue *vq); 88 89 void *virtqueue_detach_unused_buf(struct virtqueue *vq); 90 91 unsigned int virtqueue_get_vring_size(const struct virtqueue *vq); 92 93 bool virtqueue_is_broken(const struct virtqueue *vq); 94 95 const struct vring *virtqueue_get_vring(const struct virtqueue *vq); 96 dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq); 97 dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq); 98 dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq); 99 100 int virtqueue_resize(struct virtqueue *vq, u32 num, 101 void (*recycle)(struct virtqueue *vq, void *buf)); 102 103 /** 104 * struct virtio_device - representation of a device using virtio 105 * @index: unique position on the virtio bus 106 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore) 107 * @config_enabled: configuration change reporting enabled 108 * @config_change_pending: configuration change reported while disabled 109 * @config_lock: protects configuration change reporting 110 * @vqs_list_lock: protects @vqs. 111 * @dev: underlying device. 112 * @id: the device type identification (used to match it with a driver). 113 * @config: the configuration ops for this device. 114 * @vringh_config: configuration ops for host vrings. 115 * @vqs: the list of virtqueues for this device. 116 * @features: the features supported by both driver and device. 117 * @priv: private pointer for the driver's use. 118 */ 119 struct virtio_device { 120 int index; 121 bool failed; 122 bool config_enabled; 123 bool config_change_pending; 124 spinlock_t config_lock; 125 spinlock_t vqs_list_lock; 126 struct device dev; 127 struct virtio_device_id id; 128 const struct virtio_config_ops *config; 129 const struct vringh_config_ops *vringh_config; 130 struct list_head vqs; 131 u64 features; 132 void *priv; 133 }; 134 135 #define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev) 136 137 void virtio_add_status(struct virtio_device *dev, unsigned int status); 138 int register_virtio_device(struct virtio_device *dev); 139 void unregister_virtio_device(struct virtio_device *dev); 140 bool is_virtio_device(struct device *dev); 141 142 void virtio_break_device(struct virtio_device *dev); 143 void __virtio_unbreak_device(struct virtio_device *dev); 144 145 void __virtqueue_break(struct virtqueue *_vq); 146 void __virtqueue_unbreak(struct virtqueue *_vq); 147 148 void virtio_config_changed(struct virtio_device *dev); 149 #ifdef CONFIG_PM_SLEEP 150 int virtio_device_freeze(struct virtio_device *dev); 151 int virtio_device_restore(struct virtio_device *dev); 152 #endif 153 void virtio_reset_device(struct virtio_device *dev); 154 155 size_t virtio_max_dma_size(const struct virtio_device *vdev); 156 157 #define virtio_device_for_each_vq(vdev, vq) \ 158 list_for_each_entry(vq, &vdev->vqs, list) 159 160 /** 161 * struct virtio_driver - operations for a virtio I/O driver 162 * @driver: underlying device driver (populate name and owner). 163 * @id_table: the ids serviced by this driver. 164 * @feature_table: an array of feature numbers supported by this driver. 165 * @feature_table_size: number of entries in the feature table array. 166 * @feature_table_legacy: same as feature_table but when working in legacy mode. 167 * @feature_table_size_legacy: number of entries in feature table legacy array. 168 * @validate: the function to call to validate features and config space. 169 * Returns 0 or -errno. 170 * @probe: the function to call when a device is found. Returns 0 or -errno. 171 * @scan: optional function to call after successful probe; intended 172 * for virtio-scsi to invoke a scan. 173 * @remove: the function to call when a device is removed. 174 * @config_changed: optional function to call when the device configuration 175 * changes; may be called in interrupt context. 176 * @freeze: optional function to call during suspend/hibernation. 177 * @restore: optional function to call on resume. 178 */ 179 struct virtio_driver { 180 struct device_driver driver; 181 const struct virtio_device_id *id_table; 182 const unsigned int *feature_table; 183 unsigned int feature_table_size; 184 const unsigned int *feature_table_legacy; 185 unsigned int feature_table_size_legacy; 186 int (*validate)(struct virtio_device *dev); 187 int (*probe)(struct virtio_device *dev); 188 void (*scan)(struct virtio_device *dev); 189 void (*remove)(struct virtio_device *dev); 190 void (*config_changed)(struct virtio_device *dev); 191 #ifdef CONFIG_PM 192 int (*freeze)(struct virtio_device *dev); 193 int (*restore)(struct virtio_device *dev); 194 #endif 195 }; 196 197 static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv) 198 { 199 return container_of(drv, struct virtio_driver, driver); 200 } 201 202 int register_virtio_driver(struct virtio_driver *drv); 203 void unregister_virtio_driver(struct virtio_driver *drv); 204 205 /* module_virtio_driver() - Helper macro for drivers that don't do 206 * anything special in module init/exit. This eliminates a lot of 207 * boilerplate. Each module may only use this macro once, and 208 * calling it replaces module_init() and module_exit() 209 */ 210 #define module_virtio_driver(__virtio_driver) \ 211 module_driver(__virtio_driver, register_virtio_driver, \ 212 unregister_virtio_driver) 213 #endif /* _LINUX_VIRTIO_H */ 214