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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 : 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(const struct virtqueue *vq); 88 : 89 : bool virtqueue_is_broken(const struct virtqueue *vq); 90 : 91 : const struct vring *virtqueue_get_vring(const struct virtqueue *vq); 92 : dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq); 93 : dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq); 94 : dma_addr_t virtqueue_get_used_addr(const 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(const 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 0 : 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 */
