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 void *priv; 38 bool reset; 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 bool virtqueue_kick(struct virtqueue *vq); 65 66 bool virtqueue_kick_prepare(struct virtqueue *vq); 67 68 bool virtqueue_notify(struct virtqueue *vq); 69 70 void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); 71 72 void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len, 73 void **ctx); 74 75 void virtqueue_disable_cb(struct virtqueue *vq); 76 77 bool virtqueue_enable_cb(struct virtqueue *vq); 78 79 unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq); 80 81 bool virtqueue_poll(struct virtqueue *vq, unsigned); 82 83 bool virtqueue_enable_cb_delayed(struct virtqueue *vq); 84 85 void *virtqueue_detach_unused_buf(struct virtqueue *vq); 86 87 unsigned int virtqueue_get_vring_size(struct virtqueue *vq); 88 89 bool virtqueue_is_broken(struct virtqueue *vq); 90 91 const struct vring *virtqueue_get_vring(struct virtqueue *vq); 92 dma_addr_t virtqueue_get_desc_addr(struct virtqueue *vq); 93 dma_addr_t virtqueue_get_avail_addr(struct virtqueue *vq); 94 dma_addr_t virtqueue_get_used_addr(struct virtqueue *vq); 95 96 int virtqueue_resize(struct virtqueue *vq, u32 num, 97 void (*recycle)(struct virtqueue *vq, void *buf)); 98 99 /** 100 * struct virtio_device - representation of a device using virtio 101 * @index: unique position on the virtio bus 102 * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore) 103 * @config_enabled: configuration change reporting enabled 104 * @config_change_pending: configuration change reported while disabled 105 * @config_lock: protects configuration change reporting 106 * @dev: underlying device. 107 * @id: the device type identification (used to match it with a driver). 108 * @config: the configuration ops for this device. 109 * @vringh_config: configuration ops for host vrings. 110 * @vqs: the list of virtqueues for this device. 111 * @features: the features supported by both driver and device. 112 * @priv: private pointer for the driver's use. 113 */ 114 struct virtio_device { 115 int index; 116 bool failed; 117 bool config_enabled; 118 bool config_change_pending; 119 spinlock_t config_lock; 120 spinlock_t vqs_list_lock; /* Protects VQs list access */ 121 struct device dev; 122 struct virtio_device_id id; 123 const struct virtio_config_ops *config; 124 const struct vringh_config_ops *vringh_config; 125 struct list_head vqs; 126 u64 features; 127 void *priv; 128 }; 129 130 #define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev) 131 132 void virtio_add_status(struct virtio_device *dev, unsigned int status); 133 int register_virtio_device(struct virtio_device *dev); 134 void unregister_virtio_device(struct virtio_device *dev); 135 bool is_virtio_device(struct device *dev); 136 137 void virtio_break_device(struct virtio_device *dev); 138 void __virtio_unbreak_device(struct virtio_device *dev); 139 140 void __virtqueue_break(struct virtqueue *_vq); 141 void __virtqueue_unbreak(struct virtqueue *_vq); 142 143 void virtio_config_changed(struct virtio_device *dev); 144 #ifdef CONFIG_PM_SLEEP 145 int virtio_device_freeze(struct virtio_device *dev); 146 int virtio_device_restore(struct virtio_device *dev); 147 #endif 148 void virtio_reset_device(struct virtio_device *dev); 149 150 size_t virtio_max_dma_size(struct virtio_device *vdev); 151 152 #define virtio_device_for_each_vq(vdev, vq) \ 153 list_for_each_entry(vq, &vdev->vqs, list) 154 155 /** 156 * struct virtio_driver - operations for a virtio I/O driver 157 * @driver: underlying device driver (populate name and owner). 158 * @id_table: the ids serviced by this driver. 159 * @feature_table: an array of feature numbers supported by this driver. 160 * @feature_table_size: number of entries in the feature table array. 161 * @feature_table_legacy: same as feature_table but when working in legacy mode. 162 * @feature_table_size_legacy: number of entries in feature table legacy array. 163 * @probe: the function to call when a device is found. Returns 0 or -errno. 164 * @scan: optional function to call after successful probe; intended 165 * for virtio-scsi to invoke a scan. 166 * @remove: the function to call when a device is removed. 167 * @config_changed: optional function to call when the device configuration 168 * changes; may be called in interrupt context. 169 * @freeze: optional function to call during suspend/hibernation. 170 * @restore: optional function to call on resume. 171 */ 172 struct virtio_driver { 173 struct device_driver driver; 174 const struct virtio_device_id *id_table; 175 const unsigned int *feature_table; 176 unsigned int feature_table_size; 177 const unsigned int *feature_table_legacy; 178 unsigned int feature_table_size_legacy; 179 int (*validate)(struct virtio_device *dev); 180 int (*probe)(struct virtio_device *dev); 181 void (*scan)(struct virtio_device *dev); 182 void (*remove)(struct virtio_device *dev); 183 void (*config_changed)(struct virtio_device *dev); 184 #ifdef CONFIG_PM 185 int (*freeze)(struct virtio_device *dev); 186 int (*restore)(struct virtio_device *dev); 187 #endif 188 }; 189 190 static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv) 191 { 192 return container_of(drv, struct virtio_driver, driver); 193 } 194 195 int register_virtio_driver(struct virtio_driver *drv); 196 void unregister_virtio_driver(struct virtio_driver *drv); 197 198 /* module_virtio_driver() - Helper macro for drivers that don't do 199 * anything special in module init/exit. This eliminates a lot of 200 * boilerplate. Each module may only use this macro once, and 201 * calling it replaces module_init() and module_exit() 202 */ 203 #define module_virtio_driver(__virtio_driver) \ 204 module_driver(__virtio_driver, register_virtio_driver, \ 205 unregister_virtio_driver) 206 #endif /* _LINUX_VIRTIO_H */ 207