Merge tag 'block-5.15-2021-10-01' of git://git.kernel.dk/linux-block

[mirror_ubuntu-jammy-kernel.git] / include / linux / vdpa.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_VDPA_H
#define _LINUX_VDPA_H

#include <linux/kernel.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/vhost_iotlb.h>

/**
 * struct vdpa_calllback - vDPA callback definition.
 * @callback: interrupt callback function
 * @private: the data passed to the callback function
 */
struct vdpa_callback {
        irqreturn_t (*callback)(void *data);
        void *private;
};

/**
 * struct vdpa_notification_area - vDPA notification area
 * @addr: base address of the notification area
 * @size: size of the notification area
 */
struct vdpa_notification_area {
        resource_size_t addr;
        resource_size_t size;
};

/**
 * struct vdpa_vq_state_split - vDPA split virtqueue state
 * @avail_index: available index
 */
struct vdpa_vq_state_split {
        u16     avail_index;
};

/**
 * struct vdpa_vq_state_packed - vDPA packed virtqueue state
 * @last_avail_counter: last driver ring wrap counter observed by device
 * @last_avail_idx: device available index
 * @last_used_counter: device ring wrap counter
 * @last_used_idx: used index
 */
struct vdpa_vq_state_packed {
        u16     last_avail_counter:1;
        u16     last_avail_idx:15;
        u16     last_used_counter:1;
        u16     last_used_idx:15;
};

struct vdpa_vq_state {
        union {
                struct vdpa_vq_state_split split;
                struct vdpa_vq_state_packed packed;
        };
};

struct vdpa_mgmt_dev;

/**
 * struct vdpa_device - representation of a vDPA device
 * @dev: underlying device
 * @dma_dev: the actual device that is performing DMA
 * @config: the configuration ops for this device.
 * @index: device index
 * @features_valid: were features initialized? for legacy guests
 * @use_va: indicate whether virtual address must be used by this device
 * @nvqs: maximum number of supported virtqueues
 * @mdev: management device pointer; caller must setup when registering device as part
 *        of dev_add() mgmtdev ops callback before invoking _vdpa_register_device().
 */
struct vdpa_device {
        struct device dev;
        struct device *dma_dev;
        const struct vdpa_config_ops *config;
        unsigned int index;
        bool features_valid;
        bool use_va;
        int nvqs;
        struct vdpa_mgmt_dev *mdev;
};

/**
 * struct vdpa_iova_range - the IOVA range support by the device
 * @first: start of the IOVA range
 * @last: end of the IOVA range
 */
struct vdpa_iova_range {
        u64 first;
        u64 last;
};

/**
 * Corresponding file area for device memory mapping
 * @file: vma->vm_file for the mapping
 * @offset: mapping offset in the vm_file
 */
struct vdpa_map_file {
        struct file *file;
        u64 offset;
};

/**
 * struct vdpa_config_ops - operations for configuring a vDPA device.
 * Note: vDPA device drivers are required to implement all of the
 * operations unless it is mentioned to be optional in the following
 * list.
 *
 * @set_vq_address:             Set the address of virtqueue
 *                              @vdev: vdpa device
 *                              @idx: virtqueue index
 *                              @desc_area: address of desc area
 *                              @driver_area: address of driver area
 *                              @device_area: address of device area
 *                              Returns integer: success (0) or error (< 0)
 * @set_vq_num:                 Set the size of virtqueue
 *                              @vdev: vdpa device
 *                              @idx: virtqueue index
 *                              @num: the size of virtqueue
 * @kick_vq:                    Kick the virtqueue
 *                              @vdev: vdpa device
 *                              @idx: virtqueue index
 * @set_vq_cb:                  Set the interrupt callback function for
 *                              a virtqueue
 *                              @vdev: vdpa device
 *                              @idx: virtqueue index
 *                              @cb: virtio-vdev interrupt callback structure
 * @set_vq_ready:               Set ready status for a virtqueue
 *                              @vdev: vdpa device
 *                              @idx: virtqueue index
 *                              @ready: ready (true) not ready(false)
 * @get_vq_ready:               Get ready status for a virtqueue
 *                              @vdev: vdpa device
 *                              @idx: virtqueue index
 *                              Returns boolean: ready (true) or not (false)
 * @set_vq_state:               Set the state for a virtqueue
 *                              @vdev: vdpa device
 *                              @idx: virtqueue index
 *                              @state: pointer to set virtqueue state (last_avail_idx)
 *                              Returns integer: success (0) or error (< 0)
 * @get_vq_state:               Get the state for a virtqueue
 *                              @vdev: vdpa device
 *                              @idx: virtqueue index
 *                              @state: pointer to returned state (last_avail_idx)
 * @get_vq_notification:        Get the notification area for a virtqueue
 *                              @vdev: vdpa device
 *                              @idx: virtqueue index
 *                              Returns the notifcation area
 * @get_vq_irq:                 Get the irq number of a virtqueue (optional,
 *                              but must implemented if require vq irq offloading)
 *                              @vdev: vdpa device
 *                              @idx: virtqueue index
 *                              Returns int: irq number of a virtqueue,
 *                              negative number if no irq assigned.
 * @get_vq_align:               Get the virtqueue align requirement
 *                              for the device
 *                              @vdev: vdpa device
 *                              Returns virtqueue algin requirement
 * @get_features:               Get virtio features supported by the device
 *                              @vdev: vdpa device
 *                              Returns the virtio features support by the
 *                              device
 * @set_features:               Set virtio features supported by the driver
 *                              @vdev: vdpa device
 *                              @features: feature support by the driver
 *                              Returns integer: success (0) or error (< 0)
 * @set_config_cb:              Set the config interrupt callback
 *                              @vdev: vdpa device
 *                              @cb: virtio-vdev interrupt callback structure
 * @get_vq_num_max:             Get the max size of virtqueue
 *                              @vdev: vdpa device
 *                              Returns u16: max size of virtqueue
 * @get_device_id:              Get virtio device id
 *                              @vdev: vdpa device
 *                              Returns u32: virtio device id
 * @get_vendor_id:              Get id for the vendor that provides this device
 *                              @vdev: vdpa device
 *                              Returns u32: virtio vendor id
 * @get_status:                 Get the device status
 *                              @vdev: vdpa device
 *                              Returns u8: virtio device status
 * @set_status:                 Set the device status
 *                              @vdev: vdpa device
 *                              @status: virtio device status
 * @reset:                      Reset device
 *                              @vdev: vdpa device
 *                              Returns integer: success (0) or error (< 0)
 * @get_config_size:            Get the size of the configuration space
 *                              @vdev: vdpa device
 *                              Returns size_t: configuration size
 * @get_config:                 Read from device specific configuration space
 *                              @vdev: vdpa device
 *                              @offset: offset from the beginning of
 *                              configuration space
 *                              @buf: buffer used to read to
 *                              @len: the length to read from
 *                              configuration space
 * @set_config:                 Write to device specific configuration space
 *                              @vdev: vdpa device
 *                              @offset: offset from the beginning of
 *                              configuration space
 *                              @buf: buffer used to write from
 *                              @len: the length to write to
 *                              configuration space
 * @get_generation:             Get device config generation (optional)
 *                              @vdev: vdpa device
 *                              Returns u32: device generation
 * @get_iova_range:             Get supported iova range (optional)
 *                              @vdev: vdpa device
 *                              Returns the iova range supported by
 *                              the device.
 * @set_map:                    Set device memory mapping (optional)
 *                              Needed for device that using device
 *                              specific DMA translation (on-chip IOMMU)
 *                              @vdev: vdpa device
 *                              @iotlb: vhost memory mapping to be
 *                              used by the vDPA
 *                              Returns integer: success (0) or error (< 0)
 * @dma_map:                    Map an area of PA to IOVA (optional)
 *                              Needed for device that using device
 *                              specific DMA translation (on-chip IOMMU)
 *                              and preferring incremental map.
 *                              @vdev: vdpa device
 *                              @iova: iova to be mapped
 *                              @size: size of the area
 *                              @pa: physical address for the map
 *                              @perm: device access permission (VHOST_MAP_XX)
 *                              Returns integer: success (0) or error (< 0)
 * @dma_unmap:                  Unmap an area of IOVA (optional but
 *                              must be implemented with dma_map)
 *                              Needed for device that using device
 *                              specific DMA translation (on-chip IOMMU)
 *                              and preferring incremental unmap.
 *                              @vdev: vdpa device
 *                              @iova: iova to be unmapped
 *                              @size: size of the area
 *                              Returns integer: success (0) or error (< 0)
 * @free:                       Free resources that belongs to vDPA (optional)
 *                              @vdev: vdpa device
 */
struct vdpa_config_ops {
        /* Virtqueue ops */
        int (*set_vq_address)(struct vdpa_device *vdev,
                              u16 idx, u64 desc_area, u64 driver_area,
                              u64 device_area);
        void (*set_vq_num)(struct vdpa_device *vdev, u16 idx, u32 num);
        void (*kick_vq)(struct vdpa_device *vdev, u16 idx);
        void (*set_vq_cb)(struct vdpa_device *vdev, u16 idx,
                          struct vdpa_callback *cb);
        void (*set_vq_ready)(struct vdpa_device *vdev, u16 idx, bool ready);
        bool (*get_vq_ready)(struct vdpa_device *vdev, u16 idx);
        int (*set_vq_state)(struct vdpa_device *vdev, u16 idx,
                            const struct vdpa_vq_state *state);
        int (*get_vq_state)(struct vdpa_device *vdev, u16 idx,
                            struct vdpa_vq_state *state);
        struct vdpa_notification_area
        (*get_vq_notification)(struct vdpa_device *vdev, u16 idx);
        /* vq irq is not expected to be changed once DRIVER_OK is set */
        int (*get_vq_irq)(struct vdpa_device *vdv, u16 idx);

        /* Device ops */
        u32 (*get_vq_align)(struct vdpa_device *vdev);
        u64 (*get_features)(struct vdpa_device *vdev);
        int (*set_features)(struct vdpa_device *vdev, u64 features);
        void (*set_config_cb)(struct vdpa_device *vdev,
                              struct vdpa_callback *cb);
        u16 (*get_vq_num_max)(struct vdpa_device *vdev);
        u32 (*get_device_id)(struct vdpa_device *vdev);
        u32 (*get_vendor_id)(struct vdpa_device *vdev);
        u8 (*get_status)(struct vdpa_device *vdev);
        void (*set_status)(struct vdpa_device *vdev, u8 status);
        int (*reset)(struct vdpa_device *vdev);
        size_t (*get_config_size)(struct vdpa_device *vdev);
        void (*get_config)(struct vdpa_device *vdev, unsigned int offset,
                           void *buf, unsigned int len);
        void (*set_config)(struct vdpa_device *vdev, unsigned int offset,
                           const void *buf, unsigned int len);
        u32 (*get_generation)(struct vdpa_device *vdev);
        struct vdpa_iova_range (*get_iova_range)(struct vdpa_device *vdev);

        /* DMA ops */
        int (*set_map)(struct vdpa_device *vdev, struct vhost_iotlb *iotlb);
        int (*dma_map)(struct vdpa_device *vdev, u64 iova, u64 size,
                       u64 pa, u32 perm, void *opaque);
        int (*dma_unmap)(struct vdpa_device *vdev, u64 iova, u64 size);

        /* Free device resources */
        void (*free)(struct vdpa_device *vdev);
};

struct vdpa_device *__vdpa_alloc_device(struct device *parent,
                                        const struct vdpa_config_ops *config,
                                        size_t size, const char *name,
                                        bool use_va);

/**
 * vdpa_alloc_device - allocate and initilaize a vDPA device
 *
 * @dev_struct: the type of the parent structure
 * @member: the name of struct vdpa_device within the @dev_struct
 * @parent: the parent device
 * @config: the bus operations that is supported by this device
 * @name: name of the vdpa device
 * @use_va: indicate whether virtual address must be used by this device
 *
 * Return allocated data structure or ERR_PTR upon error
 */
#define vdpa_alloc_device(dev_struct, member, parent, config, name, use_va)   \
                          container_of(__vdpa_alloc_device( \
                                       parent, config, \
                                       sizeof(dev_struct) + \
                                       BUILD_BUG_ON_ZERO(offsetof( \
                                       dev_struct, member)), name, use_va), \
                                       dev_struct, member)

int vdpa_register_device(struct vdpa_device *vdev, int nvqs);
void vdpa_unregister_device(struct vdpa_device *vdev);

int _vdpa_register_device(struct vdpa_device *vdev, int nvqs);
void _vdpa_unregister_device(struct vdpa_device *vdev);

/**
 * struct vdpa_driver - operations for a vDPA driver
 * @driver: underlying device driver
 * @probe: the function to call when a device is found.  Returns 0 or -errno.
 * @remove: the function to call when a device is removed.
 */
struct vdpa_driver {
        struct device_driver driver;
        int (*probe)(struct vdpa_device *vdev);
        void (*remove)(struct vdpa_device *vdev);
};

#define vdpa_register_driver(drv) \
        __vdpa_register_driver(drv, THIS_MODULE)
int __vdpa_register_driver(struct vdpa_driver *drv, struct module *owner);
void vdpa_unregister_driver(struct vdpa_driver *drv);

#define module_vdpa_driver(__vdpa_driver) \
        module_driver(__vdpa_driver, vdpa_register_driver,      \
                      vdpa_unregister_driver)

static inline struct vdpa_driver *drv_to_vdpa(struct device_driver *driver)
{
        return container_of(driver, struct vdpa_driver, driver);
}

static inline struct vdpa_device *dev_to_vdpa(struct device *_dev)
{
        return container_of(_dev, struct vdpa_device, dev);
}

static inline void *vdpa_get_drvdata(const struct vdpa_device *vdev)
{
        return dev_get_drvdata(&vdev->dev);
}

static inline void vdpa_set_drvdata(struct vdpa_device *vdev, void *data)
{
        dev_set_drvdata(&vdev->dev, data);
}

static inline struct device *vdpa_get_dma_dev(struct vdpa_device *vdev)
{
        return vdev->dma_dev;
}

static inline int vdpa_reset(struct vdpa_device *vdev)
{
        const struct vdpa_config_ops *ops = vdev->config;

        vdev->features_valid = false;
        return ops->reset(vdev);
}

static inline int vdpa_set_features(struct vdpa_device *vdev, u64 features)
{
        const struct vdpa_config_ops *ops = vdev->config;

        vdev->features_valid = true;
        return ops->set_features(vdev, features);
}

static inline void vdpa_get_config(struct vdpa_device *vdev,
                                   unsigned int offset, void *buf,
                                   unsigned int len)
{
        const struct vdpa_config_ops *ops = vdev->config;

        /*
         * Config accesses aren't supposed to trigger before features are set.
         * If it does happen we assume a legacy guest.
         */
        if (!vdev->features_valid)
                vdpa_set_features(vdev, 0);
        ops->get_config(vdev, offset, buf, len);
}

/**
 * struct vdpa_mgmtdev_ops - vdpa device ops
 * @dev_add: Add a vdpa device using alloc and register
 *           @mdev: parent device to use for device addition
 *           @name: name of the new vdpa device
 *           Driver need to add a new device using _vdpa_register_device()
 *           after fully initializing the vdpa device. Driver must return 0
 *           on success or appropriate error code.
 * @dev_del: Remove a vdpa device using unregister
 *           @mdev: parent device to use for device removal
 *           @dev: vdpa device to remove
 *           Driver need to remove the specified device by calling
 *           _vdpa_unregister_device().
 */
struct vdpa_mgmtdev_ops {
        int (*dev_add)(struct vdpa_mgmt_dev *mdev, const char *name);
        void (*dev_del)(struct vdpa_mgmt_dev *mdev, struct vdpa_device *dev);
};

struct vdpa_mgmt_dev {
        struct device *device;
        const struct vdpa_mgmtdev_ops *ops;
        const struct virtio_device_id *id_table; /* supported ids */
        struct list_head list;
};

int vdpa_mgmtdev_register(struct vdpa_mgmt_dev *mdev);
void vdpa_mgmtdev_unregister(struct vdpa_mgmt_dev *mdev);

#endif /* _LINUX_VDPA_H */