210 lines
7.3 KiB
C
210 lines
7.3 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _LINUX_VIRTIO_H
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#define _LINUX_VIRTIO_H
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/* Everything a virtio driver needs to work with any particular virtio
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* implementation. */
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#include <linux/types.h>
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#include <linux/scatterlist.h>
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#include <linux/spinlock.h>
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#include <linux/device.h>
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#include <linux/mod_devicetable.h>
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#include <linux/gfp.h>
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/**
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* struct virtqueue - a queue to register buffers for sending or receiving.
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* @list: the chain of virtqueues for this device
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* @callback: the function to call when buffers are consumed (can be NULL).
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* @name: the name of this virtqueue (mainly for debugging)
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* @vdev: the virtio device this queue was created for.
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* @priv: a pointer for the virtqueue implementation to use.
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* @index: the zero-based ordinal number for this queue.
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* @num_free: number of elements we expect to be able to fit.
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* @num_max: the maximum number of elements supported by the device.
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* @reset: vq is in reset state or not.
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*
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* A note on @num_free: with indirect buffers, each buffer needs one
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* element in the queue, otherwise a buffer will need one element per
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* sg element.
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*/
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struct virtqueue {
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struct list_head list;
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void (*callback)(struct virtqueue *vq);
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const char *name;
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struct virtio_device *vdev;
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unsigned int index;
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unsigned int num_free;
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unsigned int num_max;
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bool reset;
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void *priv;
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};
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int virtqueue_add_outbuf(struct virtqueue *vq,
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struct scatterlist sg[], unsigned int num,
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void *data,
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gfp_t gfp);
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int virtqueue_add_inbuf(struct virtqueue *vq,
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struct scatterlist sg[], unsigned int num,
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void *data,
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gfp_t gfp);
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int virtqueue_add_inbuf_ctx(struct virtqueue *vq,
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struct scatterlist sg[], unsigned int num,
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void *data,
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void *ctx,
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gfp_t gfp);
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int virtqueue_add_sgs(struct virtqueue *vq,
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struct scatterlist *sgs[],
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unsigned int out_sgs,
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unsigned int in_sgs,
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void *data,
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gfp_t gfp);
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bool virtqueue_kick(struct virtqueue *vq);
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bool virtqueue_kick_prepare(struct virtqueue *vq);
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bool virtqueue_notify(struct virtqueue *vq);
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void *virtqueue_get_buf(struct virtqueue *vq, unsigned int *len);
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void *virtqueue_get_buf_ctx(struct virtqueue *vq, unsigned int *len,
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void **ctx);
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void virtqueue_disable_cb(struct virtqueue *vq);
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bool virtqueue_enable_cb(struct virtqueue *vq);
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unsigned virtqueue_enable_cb_prepare(struct virtqueue *vq);
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bool virtqueue_poll(struct virtqueue *vq, unsigned);
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bool virtqueue_enable_cb_delayed(struct virtqueue *vq);
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void *virtqueue_detach_unused_buf(struct virtqueue *vq);
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unsigned int virtqueue_get_vring_size(const struct virtqueue *vq);
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bool virtqueue_is_broken(const struct virtqueue *vq);
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const struct vring *virtqueue_get_vring(const struct virtqueue *vq);
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dma_addr_t virtqueue_get_desc_addr(const struct virtqueue *vq);
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dma_addr_t virtqueue_get_avail_addr(const struct virtqueue *vq);
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dma_addr_t virtqueue_get_used_addr(const struct virtqueue *vq);
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int virtqueue_resize(struct virtqueue *vq, u32 num,
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void (*recycle)(struct virtqueue *vq, void *buf));
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/**
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* struct virtio_device - representation of a device using virtio
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* @index: unique position on the virtio bus
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* @failed: saved value for VIRTIO_CONFIG_S_FAILED bit (for restore)
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* @config_enabled: configuration change reporting enabled
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* @config_change_pending: configuration change reported while disabled
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* @config_lock: protects configuration change reporting
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* @vqs_list_lock: protects @vqs.
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* @dev: underlying device.
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* @id: the device type identification (used to match it with a driver).
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* @config: the configuration ops for this device.
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* @vringh_config: configuration ops for host vrings.
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* @vqs: the list of virtqueues for this device.
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* @features: the features supported by both driver and device.
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* @priv: private pointer for the driver's use.
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*/
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struct virtio_device {
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int index;
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bool failed;
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bool config_enabled;
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bool config_change_pending;
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spinlock_t config_lock;
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spinlock_t vqs_list_lock;
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struct device dev;
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struct virtio_device_id id;
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const struct virtio_config_ops *config;
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const struct vringh_config_ops *vringh_config;
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struct list_head vqs;
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u64 features;
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void *priv;
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};
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#define dev_to_virtio(_dev) container_of_const(_dev, struct virtio_device, dev)
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void virtio_add_status(struct virtio_device *dev, unsigned int status);
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int register_virtio_device(struct virtio_device *dev);
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void unregister_virtio_device(struct virtio_device *dev);
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bool is_virtio_device(struct device *dev);
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void virtio_break_device(struct virtio_device *dev);
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void __virtio_unbreak_device(struct virtio_device *dev);
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void __virtqueue_break(struct virtqueue *_vq);
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void __virtqueue_unbreak(struct virtqueue *_vq);
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void virtio_config_changed(struct virtio_device *dev);
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#ifdef CONFIG_PM_SLEEP
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int virtio_device_freeze(struct virtio_device *dev);
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int virtio_device_restore(struct virtio_device *dev);
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#endif
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void virtio_reset_device(struct virtio_device *dev);
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size_t virtio_max_dma_size(const struct virtio_device *vdev);
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#define virtio_device_for_each_vq(vdev, vq) \
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list_for_each_entry(vq, &vdev->vqs, list)
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/**
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* struct virtio_driver - operations for a virtio I/O driver
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* @driver: underlying device driver (populate name and owner).
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* @id_table: the ids serviced by this driver.
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* @feature_table: an array of feature numbers supported by this driver.
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* @feature_table_size: number of entries in the feature table array.
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* @feature_table_legacy: same as feature_table but when working in legacy mode.
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* @feature_table_size_legacy: number of entries in feature table legacy array.
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* @validate: the function to call to validate features and config space.
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* Returns 0 or -errno.
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* @probe: the function to call when a device is found. Returns 0 or -errno.
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* @scan: optional function to call after successful probe; intended
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* for virtio-scsi to invoke a scan.
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* @remove: the function to call when a device is removed.
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* @config_changed: optional function to call when the device configuration
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* changes; may be called in interrupt context.
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* @freeze: optional function to call during suspend/hibernation.
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* @restore: optional function to call on resume.
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*/
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struct virtio_driver {
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struct device_driver driver;
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const struct virtio_device_id *id_table;
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const unsigned int *feature_table;
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unsigned int feature_table_size;
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const unsigned int *feature_table_legacy;
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unsigned int feature_table_size_legacy;
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int (*validate)(struct virtio_device *dev);
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int (*probe)(struct virtio_device *dev);
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void (*scan)(struct virtio_device *dev);
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void (*remove)(struct virtio_device *dev);
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void (*config_changed)(struct virtio_device *dev);
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#ifdef CONFIG_PM
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int (*freeze)(struct virtio_device *dev);
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int (*restore)(struct virtio_device *dev);
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#endif
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};
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static inline struct virtio_driver *drv_to_virtio(struct device_driver *drv)
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{
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return container_of(drv, struct virtio_driver, driver);
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}
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int register_virtio_driver(struct virtio_driver *drv);
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void unregister_virtio_driver(struct virtio_driver *drv);
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/* module_virtio_driver() - Helper macro for drivers that don't do
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* anything special in module init/exit. This eliminates a lot of
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* boilerplate. Each module may only use this macro once, and
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* calling it replaces module_init() and module_exit()
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*/
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#define module_virtio_driver(__virtio_driver) \
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module_driver(__virtio_driver, register_virtio_driver, \
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unregister_virtio_driver)
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#endif /* _LINUX_VIRTIO_H */
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