/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * MMU-based software IOTLB.
 *
 * Copyright (C) 2020-2021 Bytedance Inc. and/or its affiliates. All rights reserved.
 *
 * Author: Xie Yongji <xieyongji@bytedance.com>
 *
 */

#ifndef _VDUSE_IOVA_DOMAIN_H
#define _VDUSE_IOVA_DOMAIN_H

#include <linux/iova.h>
#include <linux/dma-mapping.h>
#include <linux/vhost_iotlb.h>

#define IOVA_START_PFN 1

#define BOUNCE_MAP_SHIFT        12
#define BOUNCE_MAP_SIZE (1 << BOUNCE_MAP_SHIFT)
#define BOUNCE_MAP_MASK (~(BOUNCE_MAP_SIZE - 1))
#define BOUNCE_MAP_ALIGN(addr)  (((addr) + BOUNCE_MAP_SIZE - 1) & ~(BOUNCE_MAP_SIZE - 1))

struct vduse_bounce_map {
        struct page *bounce_page;
        struct page *user_bounce_page;
        u64 orig_phys;
};

struct vduse_iova_domain {
        struct iova_domain stream_iovad;
        struct iova_domain consistent_iovad;
        struct vduse_bounce_map *bounce_maps;
        size_t bounce_size;
        unsigned long iova_limit;
        int bounce_map;
        struct vhost_iotlb *iotlb;
        spinlock_t iotlb_lock;
        struct file *file;
        bool user_bounce_pages;
        rwlock_t bounce_lock;
};

int vduse_domain_set_map(struct vduse_iova_domain *domain,
                         struct vhost_iotlb *iotlb);

void vduse_domain_clear_map(struct vduse_iova_domain *domain,
                            struct vhost_iotlb *iotlb);

void vduse_domain_sync_single_for_device(struct vduse_iova_domain *domain,
                                      dma_addr_t dma_addr, size_t size,
                                      enum dma_data_direction dir);

void vduse_domain_sync_single_for_cpu(struct vduse_iova_domain *domain,
                                      dma_addr_t dma_addr, size_t size,
                                      enum dma_data_direction dir);

dma_addr_t vduse_domain_map_page(struct vduse_iova_domain *domain,
                                 struct page *page, unsigned long offset,
                                 size_t size, enum dma_data_direction dir,
                                 unsigned long attrs);

void vduse_domain_unmap_page(struct vduse_iova_domain *domain,
                             dma_addr_t dma_addr, size_t size,
                             enum dma_data_direction dir, unsigned long attrs);

dma_addr_t vduse_domain_alloc_coherent(struct vduse_iova_domain *domain,
                                       size_t size, void *orig);

void vduse_domain_free_coherent(struct vduse_iova_domain *domain, size_t size,
                                dma_addr_t dma_addr, unsigned long attrs);

void vduse_domain_reset_bounce_map(struct vduse_iova_domain *domain);

int vduse_domain_add_user_bounce_pages(struct vduse_iova_domain *domain,
                                       struct page **pages, int count);

void vduse_domain_remove_user_bounce_pages(struct vduse_iova_domain *domain);

void vduse_domain_destroy(struct vduse_iova_domain *domain);

struct vduse_iova_domain *vduse_domain_create(unsigned long iova_limit,
                                              size_t bounce_size);

int vduse_domain_init(void);

void vduse_domain_exit(void);

#endif /* _VDUSE_IOVA_DOMAIN_H */