/* SPDX-License-Identifier: GPL-2.0 */

#ifndef VIRTIO_VFIO_COMMON_H
#define VIRTIO_VFIO_COMMON_H

#include <linux/kernel.h>
#include <linux/virtio.h>
#include <linux/vfio_pci_core.h>
#include <linux/virtio_pci.h>

enum virtiovf_migf_state {
        VIRTIOVF_MIGF_STATE_ERROR = 1,
        VIRTIOVF_MIGF_STATE_PRECOPY = 2,
        VIRTIOVF_MIGF_STATE_COMPLETE = 3,
};

enum virtiovf_load_state {
        VIRTIOVF_LOAD_STATE_READ_HEADER,
        VIRTIOVF_LOAD_STATE_PREP_HEADER_DATA,
        VIRTIOVF_LOAD_STATE_READ_HEADER_DATA,
        VIRTIOVF_LOAD_STATE_PREP_CHUNK,
        VIRTIOVF_LOAD_STATE_READ_CHUNK,
        VIRTIOVF_LOAD_STATE_LOAD_CHUNK,
};

struct virtiovf_data_buffer {
        struct sg_append_table table;
        loff_t start_pos;
        u64 length;
        u64 allocated_length;
        struct list_head buf_elm;
        u8 include_header_object:1;
        struct virtiovf_migration_file *migf;
        /* Optimize virtiovf_get_migration_page() for sequential access */
        struct scatterlist *last_offset_sg;
        unsigned int sg_last_entry;
        unsigned long last_offset;
};

enum virtiovf_migf_header_flags {
        VIRTIOVF_MIGF_HEADER_FLAGS_TAG_MANDATORY = 0,
        VIRTIOVF_MIGF_HEADER_FLAGS_TAG_OPTIONAL = 1 << 0,
};

enum virtiovf_migf_header_tag {
        VIRTIOVF_MIGF_HEADER_TAG_DEVICE_DATA = 0,
};

struct virtiovf_migration_header {
        __le64 record_size;
        /* For future use in case we may need to change the kernel protocol */
        __le32 flags; /* Use virtiovf_migf_header_flags */
        __le32 tag; /* Use virtiovf_migf_header_tag */
        __u8 data[]; /* Its size is given in the record_size */
};

struct virtiovf_migration_file {
        struct file *filp;
        /* synchronize access to the file state */
        struct mutex lock;
        loff_t max_pos;
        u64 pre_copy_initial_bytes;
        struct ratelimit_state pre_copy_rl_state;
        u64 record_size;
        u32 record_tag;
        u8 has_obj_id:1;
        u32 obj_id;
        enum virtiovf_migf_state state;
        enum virtiovf_load_state load_state;
        /* synchronize access to the lists */
        struct mutex list_lock;
        struct list_head buf_list;
        struct list_head avail_list;
        struct virtiovf_data_buffer *buf;
        struct virtiovf_data_buffer *buf_header;
        struct virtiovf_pci_core_device *virtvdev;
};

struct virtiovf_pci_core_device {
        struct vfio_pci_core_device core_device;
#ifdef CONFIG_VIRTIO_VFIO_PCI_ADMIN_LEGACY
        u8 *bar0_virtual_buf;
        /* synchronize access to the virtual buf */
        struct mutex bar_mutex;
        void __iomem *notify_addr;
        u64 notify_offset;
        __le32 pci_base_addr_0;
        __le16 pci_cmd;
        u8 bar0_virtual_buf_size;
        u8 notify_bar;
#endif

        /* LM related */
        u8 migrate_cap:1;
        u8 deferred_reset:1;
        /* protect migration state */
        struct mutex state_mutex;
        enum vfio_device_mig_state mig_state;
        /* protect the reset_done flow */
        spinlock_t reset_lock;
        struct virtiovf_migration_file *resuming_migf;
        struct virtiovf_migration_file *saving_migf;
};

void virtiovf_set_migratable(struct virtiovf_pci_core_device *virtvdev);
void virtiovf_open_migration(struct virtiovf_pci_core_device *virtvdev);
void virtiovf_close_migration(struct virtiovf_pci_core_device *virtvdev);
void virtiovf_migration_reset_done(struct pci_dev *pdev);

#ifdef CONFIG_VIRTIO_VFIO_PCI_ADMIN_LEGACY
int virtiovf_open_legacy_io(struct virtiovf_pci_core_device *virtvdev);
int virtiovf_pci_ioctl_get_region_info(struct vfio_device *core_vdev,
                                       struct vfio_region_info *info,
                                       struct vfio_info_cap *caps);
ssize_t virtiovf_pci_core_write(struct vfio_device *core_vdev,
                                const char __user *buf, size_t count,
                                loff_t *ppos);
ssize_t virtiovf_pci_core_read(struct vfio_device *core_vdev, char __user *buf,
                               size_t count, loff_t *ppos);
bool virtiovf_support_legacy_io(struct pci_dev *pdev);
int virtiovf_init_legacy_io(struct virtiovf_pci_core_device *virtvdev);
void virtiovf_release_legacy_io(struct virtiovf_pci_core_device *virtvdev);
void virtiovf_legacy_io_reset_done(struct pci_dev *pdev);
#endif

#endif /* VIRTIO_VFIO_COMMON_H */