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