| 1 | #ifndef _LINUX_VIRTIO_H |
| 2 | #define _LINUX_VIRTIO_H |
| 3 | /* Everything a virtio driver needs to work with any particular virtio |
| 4 | * implementation. */ |
| 5 | #include <linux/types.h> |
| 6 | #include <linux/scatterlist.h> |
| 7 | #include <linux/spinlock.h> |
| 8 | #include <linux/device.h> |
| 9 | #include <linux/mod_devicetable.h> |
| 10 | #include <linux/gfp.h> |
| 11 | #include <linux/vringh.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_sgs(struct virtqueue *vq, |
| 48 | struct scatterlist *sgs[], |
| 49 | unsigned int out_sgs, |
| 50 | unsigned int in_sgs, |
| 51 | void *data, |
| 52 | gfp_t gfp); |
| 53 | |
| 54 | bool virtqueue_kick(struct virtqueue *vq); |
| 55 | |
| 56 | bool virtqueue_kick_prepare(struct virtqueue *vq); |
| 57 | |
| 58 | bool virtqueue_notify(struct virtqueue *vq); |
| 59 | |
| 60 | void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len); |
| 61 | |
| 62 | void virtqueue_disable_cb(struct virtqueue *vq); |
| 63 | |
| 64 | bool virtqueue_enable_cb(struct virtqueue *vq); |
| 65 | |
| 66 | unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq); |
| 67 | |
| 68 | bool virtqueue_poll(struct virtqueue *vq, unsigned); |
| 69 | |
| 70 | bool virtqueue_enable_cb_delayed(struct virtqueue *vq); |
| 71 | |
| 72 | void *virtqueue_detach_unused_buf(struct virtqueue *vq); |
| 73 | |
| 74 | unsigned int virtqueue_get_vring_size(struct virtqueue *vq); |
| 75 | |
| 76 | bool virtqueue_is_broken(struct virtqueue *vq); |
| 77 | |
| 78 | const struct vring *virtqueue_get_vring(struct virtqueue *vq); |
| 79 | dma_addr_t virtqueue_get_desc_addr(struct virtqueue *vq); |
| 80 | dma_addr_t virtqueue_get_avail_addr(struct virtqueue *vq); |
| 81 | dma_addr_t virtqueue_get_used_addr(struct virtqueue *vq); |
| 82 | |
| 83 | /* |
| 84 | * Legacy accessors -- in almost all cases, these are the wrong functions |
| 85 | * to use. |
| 86 | */ |
| 87 | static inline void *virtqueue_get_desc(struct virtqueue *vq) |
| 88 | { |
| 89 | return virtqueue_get_vring(vq)->desc; |
| 90 | } |
| 91 | static inline void *virtqueue_get_avail(struct virtqueue *vq) |
| 92 | { |
| 93 | return virtqueue_get_vring(vq)->avail; |
| 94 | } |
| 95 | static inline void *virtqueue_get_used(struct virtqueue *vq) |
| 96 | { |
| 97 | return virtqueue_get_vring(vq)->used; |
| 98 | } |
| 99 | |
| 100 | /** |
| 101 | * virtio_device - representation of a device using virtio |
| 102 | * @index: unique position on the virtio bus |
| 103 | * @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore) |
| 104 | * @config_enabled: configuration change reporting enabled |
| 105 | * @config_change_pending: configuration change reported while disabled |
| 106 | * @config_lock: protects configuration change reporting |
| 107 | * @dev: underlying device. |
| 108 | * @id: the device type identification (used to match it with a driver). |
| 109 | * @config: the configuration ops for this device. |
| 110 | * @vringh_config: configuration ops for host vrings. |
| 111 | * @vqs: the list of virtqueues for this device. |
| 112 | * @features: the features supported by both driver and device. |
| 113 | * @priv: private pointer for the driver's use. |
| 114 | */ |
| 115 | struct virtio_device { |
| 116 | int index; |
| 117 | bool failed; |
| 118 | bool config_enabled; |
| 119 | bool config_change_pending; |
| 120 | spinlock_t config_lock; |
| 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 | static inline struct virtio_device *dev_to_virtio(struct device *_dev) |
| 131 | { |
| 132 | return container_of(_dev, struct virtio_device, dev); |
| 133 | } |
| 134 | |
| 135 | int register_virtio_device(struct virtio_device *dev); |
| 136 | void unregister_virtio_device(struct virtio_device *dev); |
| 137 | |
| 138 | void virtio_break_device(struct virtio_device *dev); |
| 139 | |
| 140 | void virtio_config_changed(struct virtio_device *dev); |
| 141 | #ifdef CONFIG_PM_SLEEP |
| 142 | int virtio_device_freeze(struct virtio_device *dev); |
| 143 | int virtio_device_restore(struct virtio_device *dev); |
| 144 | #endif |
| 145 | |
| 146 | /** |
| 147 | * virtio_driver - operations for a virtio I/O driver |
| 148 | * @driver: underlying device driver (populate name and owner). |
| 149 | * @id_table: the ids serviced by this driver. |
| 150 | * @feature_table: an array of feature numbers supported by this driver. |
| 151 | * @feature_table_size: number of entries in the feature table array. |
| 152 | * @feature_table_legacy: same as feature_table but when working in legacy mode. |
| 153 | * @feature_table_size_legacy: number of entries in feature table legacy array. |
| 154 | * @probe: the function to call when a device is found. Returns 0 or -errno. |
| 155 | * @remove: the function to call when a device is removed. |
| 156 | * @config_changed: optional function to call when the device configuration |
| 157 | * changes; may be called in interrupt context. |
| 158 | */ |
| 159 | struct virtio_driver { |
| 160 | struct device_driver driver; |
| 161 | const struct virtio_device_id *id_table; |
| 162 | const unsigned int *feature_table; |
| 163 | unsigned int feature_table_size; |
| 164 | const unsigned int *feature_table_legacy; |
| 165 | unsigned int feature_table_size_legacy; |
| 166 | int (*probe)(struct virtio_device *dev); |
| 167 | void (*scan)(struct virtio_device *dev); |
| 168 | void (*remove)(struct virtio_device *dev); |
| 169 | void (*config_changed)(struct virtio_device *dev); |
| 170 | #ifdef CONFIG_PM |
| 171 | int (*freeze)(struct virtio_device *dev); |
| 172 | int (*restore)(struct virtio_device *dev); |
| 173 | #endif |
| 174 | }; |
| 175 | |
| 176 | static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv) |
| 177 | { |
| 178 | return container_of(drv, struct virtio_driver, driver); |
| 179 | } |
| 180 | |
| 181 | int register_virtio_driver(struct virtio_driver *drv); |
| 182 | void unregister_virtio_driver(struct virtio_driver *drv); |
| 183 | |
| 184 | /* module_virtio_driver() - Helper macro for drivers that don't do |
| 185 | * anything special in module init/exit. This eliminates a lot of |
| 186 | * boilerplate. Each module may only use this macro once, and |
| 187 | * calling it replaces module_init() and module_exit() |
| 188 | */ |
| 189 | #define module_virtio_driver(__virtio_driver) \ |
| 190 | module_driver(__virtio_driver, register_virtio_driver, \ |
| 191 | unregister_virtio_driver) |
| 192 | #endif /* _LINUX_VIRTIO_H */ |