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