/*
 * Copyright 2009 Jerome Glisse.
 * All Rights Reserved.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sub license, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE.
 *
 * The above copyright notice and this permission notice (including the
 * next paragraph) shall be included in all copies or substantial portions
 * of the Software.
 *
 */
/*
 * Authors:
 *    Jerome Glisse <glisse@freedesktop.org>
 *    Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
 *    Dave Airlie
 */
#include <drm/ttm/ttm_bo_api.h>
#include <drm/ttm/ttm_bo_driver.h>
#include <drm/ttm/ttm_placement.h>
#include <drm/ttm/ttm_module.h>
#include <drm/ttm/ttm_page_alloc.h>
#include <drm/drmP.h>
#include <drm/radeon_drm.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/swiotlb.h>
#include <linux/swap.h>
#include <linux/pagemap.h>
#include <linux/debugfs.h>
#include "radeon_reg.h"
#include "radeon.h"

#define DRM_FILE_PAGE_OFFSET (0x100000000ULL >> PAGE_SHIFT)

static int radeon_ttm_debugfs_init(struct radeon_device *rdev);
static void radeon_ttm_debugfs_fini(struct radeon_device *rdev);

static struct radeon_device *radeon_get_rdev(struct ttm_bo_device *bdev)
{
        struct radeon_mman *mman;
        struct radeon_device *rdev;

        mman = container_of(bdev, struct radeon_mman, bdev);
        rdev = container_of(mman, struct radeon_device, mman);
        return rdev;
}


/*
 * Global memory.
 */
static int radeon_ttm_mem_global_init(struct drm_global_reference *ref)
{
        return ttm_mem_global_init(ref->object);
}

static void radeon_ttm_mem_global_release(struct drm_global_reference *ref)
{
        ttm_mem_global_release(ref->object);
}

static int radeon_ttm_global_init(struct radeon_device *rdev)
{
        struct drm_global_reference *global_ref;
        int r;

        rdev->mman.mem_global_referenced = false;
        global_ref = &rdev->mman.mem_global_ref;
        global_ref->global_type = DRM_GLOBAL_TTM_MEM;
        global_ref->size = sizeof(struct ttm_mem_global);
        global_ref->init = &radeon_ttm_mem_global_init;
        global_ref->release = &radeon_ttm_mem_global_release;
        r = drm_global_item_ref(global_ref);
        if (r != 0) {
                DRM_ERROR("Failed setting up TTM memory accounting "
                          "subsystem.\n");
                return r;
        }

        rdev->mman.bo_global_ref.mem_glob =
                rdev->mman.mem_global_ref.object;
        global_ref = &rdev->mman.bo_global_ref.ref;
        global_ref->global_type = DRM_GLOBAL_TTM_BO;
        global_ref->size = sizeof(struct ttm_bo_global);
        global_ref->init = &ttm_bo_global_init;
        global_ref->release = &ttm_bo_global_release;
        r = drm_global_item_ref(global_ref);
        if (r != 0) {
                DRM_ERROR("Failed setting up TTM BO subsystem.\n");
                drm_global_item_unref(&rdev->mman.mem_global_ref);
                return r;
        }

        rdev->mman.mem_global_referenced = true;
        return 0;
}

static void radeon_ttm_global_fini(struct radeon_device *rdev)
{
        if (rdev->mman.mem_global_referenced) {
                drm_global_item_unref(&rdev->mman.bo_global_ref.ref);
                drm_global_item_unref(&rdev->mman.mem_global_ref);
                rdev->mman.mem_global_referenced = false;
        }
}

static int radeon_invalidate_caches(struct ttm_bo_device *bdev, uint32_t flags)
{
        return 0;
}

static int radeon_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
                                struct ttm_mem_type_manager *man)
{
        struct radeon_device *rdev;

        rdev = radeon_get_rdev(bdev);

        switch (type) {
        case TTM_PL_SYSTEM:
                /* System memory */
                man->flags = TTM_MEMTYPE_FLAG_MAPPABLE;
                man->available_caching = TTM_PL_MASK_CACHING;
                man->default_caching = TTM_PL_FLAG_CACHED;
                break;
        case TTM_PL_TT:
                man->func = &ttm_bo_manager_func;
                man->gpu_offset = rdev->mc.gtt_start;
                man->available_caching = TTM_PL_MASK_CACHING;
                man->default_caching = TTM_PL_FLAG_CACHED;
                man->flags = TTM_MEMTYPE_FLAG_MAPPABLE | TTM_MEMTYPE_FLAG_CMA;
#if IS_ENABLED(CONFIG_AGP)
                if (rdev->flags & RADEON_IS_AGP) {
                        if (!rdev->ddev->agp) {
                                DRM_ERROR("AGP is not enabled for memory type %u\n",
                                          (unsigned)type);
                                return -EINVAL;
                        }
                        if (!rdev->ddev->agp->cant_use_aperture)
                                man->flags = TTM_MEMTYPE_FLAG_MAPPABLE;
                        man->available_caching = TTM_PL_FLAG_UNCACHED |
                                                 TTM_PL_FLAG_WC;
                        man->default_caching = TTM_PL_FLAG_WC;
                }
#endif
                break;
        case TTM_PL_VRAM:
                /* "On-card" video ram */
                man->func = &ttm_bo_manager_func;
                man->gpu_offset = rdev->mc.vram_start;
                man->flags = TTM_MEMTYPE_FLAG_FIXED |
                             TTM_MEMTYPE_FLAG_MAPPABLE;
                man->available_caching = TTM_PL_FLAG_UNCACHED | TTM_PL_FLAG_WC;
                man->default_caching = TTM_PL_FLAG_WC;
                break;
        default:
                DRM_ERROR("Unsupported memory type %u\n", (unsigned)type);
                return -EINVAL;
        }
        return 0;
}

static void radeon_evict_flags(struct ttm_buffer_object *bo,
                                struct ttm_placement *placement)
{
        static const struct ttm_place placements = {
                .fpfn = 0,
                .lpfn = 0,
                .flags = TTM_PL_MASK_CACHING | TTM_PL_FLAG_SYSTEM
        };

        struct radeon_bo *rbo;

        if (!radeon_ttm_bo_is_radeon_bo(bo)) {
                placement->placement = &placements;
                placement->busy_placement = &placements;
                placement->num_placement = 1;
                placement->num_busy_placement = 1;
                return;
        }
        rbo = container_of(bo, struct radeon_bo, tbo);
        switch (bo->mem.mem_type) {
        case TTM_PL_VRAM:
                if (rbo->rdev->ring[radeon_copy_ring_index(rbo->rdev)].ready == false)
                        radeon_ttm_placement_from_domain(rbo, RADEON_GEM_DOMAIN_CPU);
                else if (rbo->rdev->mc.visible_vram_size < rbo->rdev->mc.real_vram_size &&
                         bo->mem.start < (rbo->rdev->mc.visible_vram_size >> PAGE_SHIFT)) {
                        unsigned fpfn = rbo->rdev->mc.visible_vram_size >> PAGE_SHIFT;
                        int i;

                        /* Try evicting to the CPU inaccessible part of VRAM
                         * first, but only set GTT as busy placement, so this
                         * BO will be evicted to GTT rather than causing other
                         * BOs to be evicted from VRAM
                         */
                        radeon_ttm_placement_from_domain(rbo, RADEON_GEM_DOMAIN_VRAM |
                                                         RADEON_GEM_DOMAIN_GTT);
                        rbo->placement.num_busy_placement = 0;
                        for (i = 0; i < rbo->placement.num_placement; i++) {
                                if (rbo->placements[i].flags & TTM_PL_FLAG_VRAM) {
                                        if (rbo->placements[i].fpfn < fpfn)
                                                rbo->placements[i].fpfn = fpfn;
                                } else {
                                        rbo->placement.busy_placement =
                                                &rbo->placements[i];
                                        rbo->placement.num_busy_placement = 1;
                                }
                        }
                } else
                        radeon_ttm_placement_from_domain(rbo, RADEON_GEM_DOMAIN_GTT);
                break;
        case TTM_PL_TT:
        default:
                radeon_ttm_placement_from_domain(rbo, RADEON_GEM_DOMAIN_CPU);
        }
        *placement = rbo->placement;
}

static int radeon_verify_access(struct ttm_buffer_object *bo, struct file *filp)
{
        struct radeon_bo *rbo = container_of(bo, struct radeon_bo, tbo);

        if (radeon_ttm_tt_has_userptr(bo->ttm))
                return -EPERM;
        return drm_vma_node_verify_access(&rbo->gem_base.vma_node,
                                          filp->private_data);
}

static void radeon_move_null(struct ttm_buffer_object *bo,
                             struct ttm_mem_reg *new_mem)
{
        struct ttm_mem_reg *old_mem = &bo->mem;

        BUG_ON(old_mem->mm_node != NULL);
        *old_mem = *new_mem;
        new_mem->mm_node = NULL;
}

static int radeon_move_blit(struct ttm_buffer_object *bo,
                        bool evict, bool no_wait_gpu,
                        struct ttm_mem_reg *new_mem,
                        struct ttm_mem_reg *old_mem)
{
        struct radeon_device *rdev;
        uint64_t old_start, new_start;
        struct radeon_fence *fence;
        unsigned num_pages;
        int r, ridx;

        rdev = radeon_get_rdev(bo->bdev);
        ridx = radeon_copy_ring_index(rdev);
        old_start = (u64)old_mem->start << PAGE_SHIFT;
        new_start = (u64)new_mem->start << PAGE_SHIFT;

        switch (old_mem->mem_type) {
        case TTM_PL_VRAM:
                old_start += rdev->mc.vram_start;
                break;
        case TTM_PL_TT:
                old_start += rdev->mc.gtt_start;
                break;
        default:
                DRM_ERROR("Unknown placement %d\n", old_mem->mem_type);
                return -EINVAL;
        }
        switch (new_mem->mem_type) {
        case TTM_PL_VRAM:
                new_start += rdev->mc.vram_start;
                break;
        case TTM_PL_TT:
                new_start += rdev->mc.gtt_start;
                break;
        default:
                DRM_ERROR("Unknown placement %d\n", old_mem->mem_type);
                return -EINVAL;
        }
        if (!rdev->ring[ridx].ready) {
                DRM_ERROR("Trying to move memory with ring turned off.\n");
                return -EINVAL;
        }

        BUILD_BUG_ON((PAGE_SIZE % RADEON_GPU_PAGE_SIZE) != 0);

        num_pages = new_mem->num_pages * (PAGE_SIZE / RADEON_GPU_PAGE_SIZE);
        fence = radeon_copy(rdev, old_start, new_start, num_pages, bo->resv);
        if (IS_ERR(fence))
                return PTR_ERR(fence);

        r = ttm_bo_move_accel_cleanup(bo, &fence->base, evict, new_mem);
        radeon_fence_unref(&fence);
        return r;
}

static int radeon_move_vram_ram(struct ttm_buffer_object *bo,
                                bool evict, bool interruptible,
                                bool no_wait_gpu,
                                struct ttm_mem_reg *new_mem)
{
        struct radeon_device *rdev;
        struct ttm_mem_reg *old_mem = &bo->mem;
        struct ttm_mem_reg tmp_mem;
        struct ttm_place placements;
        struct ttm_placement placement;
        int r;

        rdev = radeon_get_rdev(bo->bdev);
        tmp_mem = *new_mem;
        tmp_mem.mm_node = NULL;
        placement.num_placement = 1;
        placement.placement = &placements;
        placement.num_busy_placement = 1;
        placement.busy_placement = &placements;
        placements.fpfn = 0;
        placements.lpfn = 0;
        placements.flags = TTM_PL_MASK_CACHING | TTM_PL_FLAG_TT;
        r = ttm_bo_mem_space(bo, &placement, &tmp_mem,
                             interruptible, no_wait_gpu);
        if (unlikely(r)) {
                return r;
        }

        r = ttm_tt_set_placement_caching(bo->ttm, tmp_mem.placement);
        if (unlikely(r)) {
                goto out_cleanup;
        }

        r = ttm_tt_bind(bo->ttm, &tmp_mem);
        if (unlikely(r)) {
                goto out_cleanup;
        }
        r = radeon_move_blit(bo, true, no_wait_gpu, &tmp_mem, old_mem);
        if (unlikely(r)) {
                goto out_cleanup;
        }
        r = ttm_bo_move_ttm(bo, interruptible, no_wait_gpu, new_mem);
out_cleanup:
        ttm_bo_mem_put(bo, &tmp_mem);
        return r;
}

static int radeon_move_ram_vram(struct ttm_buffer_object *bo,
                                bool evict, bool interruptible,
                                bool no_wait_gpu,
                                struct ttm_mem_reg *new_mem)
{
        struct radeon_device *rdev;
        struct ttm_mem_reg *old_mem = &bo->mem;
        struct ttm_mem_reg tmp_mem;
        struct ttm_placement placement;
        struct ttm_place placements;
        int r;

        rdev = radeon_get_rdev(bo->bdev);
        tmp_mem = *new_mem;
        tmp_mem.mm_node = NULL;
        placement.num_placement = 1;
        placement.placement = &placements;
        placement.num_busy_placement = 1;
        placement.busy_placement = &placements;
        placements.fpfn = 0;
        placements.lpfn = 0;
        placements.flags = TTM_PL_MASK_CACHING | TTM_PL_FLAG_TT;
        r = ttm_bo_mem_space(bo, &placement, &tmp_mem,
                             interruptible, no_wait_gpu);
        if (unlikely(r)) {
                return r;
        }
        r = ttm_bo_move_ttm(bo, interruptible, no_wait_gpu, &tmp_mem);
        if (unlikely(r)) {
                goto out_cleanup;
        }
        r = radeon_move_blit(bo, true, no_wait_gpu, new_mem, old_mem);
        if (unlikely(r)) {
                goto out_cleanup;
        }
out_cleanup:
        ttm_bo_mem_put(bo, &tmp_mem);
        return r;
}

static int radeon_bo_move(struct ttm_buffer_object *bo,
                        bool evict, bool interruptible,
                        bool no_wait_gpu,
                        struct ttm_mem_reg *new_mem)
{
        struct radeon_device *rdev;
        struct radeon_bo *rbo;
        struct ttm_mem_reg *old_mem = &bo->mem;
        int r;

        r = ttm_bo_wait(bo, interruptible, no_wait_gpu);
        if (r)
                return r;

        /* Can't move a pinned BO */
        rbo = container_of(bo, struct radeon_bo, tbo);
        if (WARN_ON_ONCE(rbo->pin_count > 0))
                return -EINVAL;

        rdev = radeon_get_rdev(bo->bdev);
        if (old_mem->mem_type == TTM_PL_SYSTEM && bo->ttm == NULL) {
                radeon_move_null(bo, new_mem);
                return 0;
        }
        if ((old_mem->mem_type == TTM_PL_TT &&
             new_mem->mem_type == TTM_PL_SYSTEM) ||
            (old_mem->mem_type == TTM_PL_SYSTEM &&
             new_mem->mem_type == TTM_PL_TT)) {
                /* bind is enough */
                radeon_move_null(bo, new_mem);
                return 0;
        }
        if (!rdev->ring[radeon_copy_ring_index(rdev)].ready ||
            rdev->asic->copy.copy == NULL) {
                /* use memcpy */
                goto memcpy;
        }

        if (old_mem->mem_type == TTM_PL_VRAM &&
            new_mem->mem_type == TTM_PL_SYSTEM) {
                r = radeon_move_vram_ram(bo, evict, interruptible,
                                        no_wait_gpu, new_mem);
        } else if (old_mem->mem_type == TTM_PL_SYSTEM &&
                   new_mem->mem_type == TTM_PL_VRAM) {
                r = radeon_move_ram_vram(bo, evict, interruptible,
                                            no_wait_gpu, new_mem);
        } else {
                r = radeon_move_blit(bo, evict, no_wait_gpu, new_mem, old_mem);
        }

        if (r) {
memcpy:
                r = ttm_bo_move_memcpy(bo, interruptible, no_wait_gpu, new_mem);
                if (r) {
                        return r;
                }
        }

        /* update statistics */
        atomic64_add((u64)bo->num_pages << PAGE_SHIFT, &rdev->num_bytes_moved);
        return 0;
}

static int radeon_ttm_io_mem_reserve(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem)
{
        struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
        struct radeon_device *rdev = radeon_get_rdev(bdev);

        mem->bus.addr = NULL;
        mem->bus.offset = 0;
        mem->bus.size = mem->num_pages << PAGE_SHIFT;
        mem->bus.base = 0;
        mem->bus.is_iomem = false;
        if (!(man->flags & TTM_MEMTYPE_FLAG_MAPPABLE))
                return -EINVAL;
        switch (mem->mem_type) {
        case TTM_PL_SYSTEM:
                /* system memory */
                return 0;
        case TTM_PL_TT:
#if IS_ENABLED(CONFIG_AGP)
                if (rdev->flags & RADEON_IS_AGP) {
                        /* RADEON_IS_AGP is set only if AGP is active */
                        mem->bus.offset = mem->start << PAGE_SHIFT;
                        mem->bus.base = rdev->mc.agp_base;
                        mem->bus.is_iomem = !rdev->ddev->agp->cant_use_aperture;
                }
#endif
                break;
        case TTM_PL_VRAM:
                mem->bus.offset = mem->start << PAGE_SHIFT;
                /* check if it's visible */
                if ((mem->bus.offset + mem->bus.size) > rdev->mc.visible_vram_size)
                        return -EINVAL;
                mem->bus.base = rdev->mc.aper_base;
                mem->bus.is_iomem = true;
#ifdef __alpha__
                /*
                 * Alpha: use bus.addr to hold the ioremap() return,
                 * so we can modify bus.base below.
                 */
                if (mem->placement & TTM_PL_FLAG_WC)
                        mem->bus.addr =
                                ioremap_wc(mem->bus.base + mem->bus.offset,
                                           mem->bus.size);
                else
                        mem->bus.addr =
                                ioremap_nocache(mem->bus.base + mem->bus.offset,
                                                mem->bus.size);
                if (!mem->bus.addr)
                        return -ENOMEM;

                /*
                 * Alpha: Use just the bus offset plus
                 * the hose/domain memory base for bus.base.
                 * It then can be used to build PTEs for VRAM
                 * access, as done in ttm_bo_vm_fault().
                 */
                mem->bus.base = (mem->bus.base & 0x0ffffffffUL) +
                        rdev->ddev->hose->dense_mem_base;
#endif
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

static void radeon_ttm_io_mem_free(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem)
{
}

/*
 * TTM backend functions.
 */
struct radeon_ttm_tt {
        struct ttm_dma_tt               ttm;
        struct radeon_device            *rdev;
        u64                             offset;

        uint64_t                        userptr;
        struct mm_struct                *usermm;
        uint32_t                        userflags;
};

/* prepare the sg table with the user pages */
static int radeon_ttm_tt_pin_userptr(struct ttm_tt *ttm)
{
        struct radeon_device *rdev = radeon_get_rdev(ttm->bdev);
        struct radeon_ttm_tt *gtt = (void *)ttm;
        unsigned pinned = 0, nents;
        int r;

        int write = !(gtt->userflags & RADEON_GEM_USERPTR_READONLY);
        enum dma_data_direction direction = write ?
                DMA_BIDIRECTIONAL : DMA_TO_DEVICE;

        if (current->mm != gtt->usermm)
                return -EPERM;

        if (gtt->userflags & RADEON_GEM_USERPTR_ANONONLY) {
                /* check that we only pin down anonymous memory
                   to prevent problems with writeback */
                unsigned long end = gtt->userptr + ttm->num_pages * PAGE_SIZE;
                struct vm_area_struct *vma;
                vma = find_vma(gtt->usermm, gtt->userptr);
                if (!vma || vma->vm_file || vma->vm_end < end)
                        return -EPERM;
        }

        do {
                unsigned num_pages = ttm->num_pages - pinned;
                uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE;
                struct page **pages = ttm->pages + pinned;

                r = get_user_pages(userptr, num_pages, write ? FOLL_WRITE : 0,
                                   pages, NULL);
                if (r < 0)
                        goto release_pages;

                pinned += r;

        } while (pinned < ttm->num_pages);

        r = sg_alloc_table_from_pages(ttm->sg, ttm->pages, ttm->num_pages, 0,
                                      ttm->num_pages << PAGE_SHIFT,
                                      GFP_KERNEL);
        if (r)
                goto release_sg;

        r = -ENOMEM;
        nents = dma_map_sg(rdev->dev, ttm->sg->sgl, ttm->sg->nents, direction);
        if (nents != ttm->sg->nents)
                goto release_sg;

        drm_prime_sg_to_page_addr_arrays(ttm->sg, ttm->pages,
                                         gtt->ttm.dma_address, ttm->num_pages);

        return 0;

release_sg:
        kfree(ttm->sg);

release_pages:
        release_pages(ttm->pages, pinned);
        return r;
}

static void radeon_ttm_tt_unpin_userptr(struct ttm_tt *ttm)
{
        struct radeon_device *rdev = radeon_get_rdev(ttm->bdev);
        struct radeon_ttm_tt *gtt = (void *)ttm;
        struct sg_page_iter sg_iter;

        int write = !(gtt->userflags & RADEON_GEM_USERPTR_READONLY);
        enum dma_data_direction direction = write ?
                DMA_BIDIRECTIONAL : DMA_TO_DEVICE;

        /* double check that we don't free the table twice */
        if (!ttm->sg->sgl)
                return;

        /* free the sg table and pages again */
        dma_unmap_sg(rdev->dev, ttm->sg->sgl, ttm->sg->nents, direction);

        for_each_sg_page(ttm->sg->sgl, &sg_iter, ttm->sg->nents, 0) {
                struct page *page = sg_page_iter_page(&sg_iter);
                if (!(gtt->userflags & RADEON_GEM_USERPTR_READONLY))
                        set_page_dirty(page);

                mark_page_accessed(page);
                put_page(page);
        }

        sg_free_table(ttm->sg);
}

static int radeon_ttm_backend_bind(struct ttm_tt *ttm,
                                   struct ttm_mem_reg *bo_mem)
{
        struct radeon_ttm_tt *gtt = (void*)ttm;
        uint32_t flags = RADEON_GART_PAGE_VALID | RADEON_GART_PAGE_READ |
                RADEON_GART_PAGE_WRITE;
        int r;

        if (gtt->userptr) {
                radeon_ttm_tt_pin_userptr(ttm);
                flags &= ~RADEON_GART_PAGE_WRITE;
        }

        gtt->offset = (unsigned long)(bo_mem->start << PAGE_SHIFT);
        if (!ttm->num_pages) {
                WARN(1, "nothing to bind %lu pages for mreg %p back %p!\n",
                     ttm->num_pages, bo_mem, ttm);
        }
        if (ttm->caching_state == tt_cached)
                flags |= RADEON_GART_PAGE_SNOOP;
        r = radeon_gart_bind(gtt->rdev, gtt->offset, ttm->num_pages,
                             ttm->pages, gtt->ttm.dma_address, flags);
        if (r) {
                DRM_ERROR("failed to bind %lu pages at 0x%08X\n",
                          ttm->num_pages, (unsigned)gtt->offset);
                return r;
        }
        return 0;
}

static int radeon_ttm_backend_unbind(struct ttm_tt *ttm)
{
        struct radeon_ttm_tt *gtt = (void *)ttm;

        radeon_gart_unbind(gtt->rdev, gtt->offset, ttm->num_pages);

        if (gtt->userptr)
                radeon_ttm_tt_unpin_userptr(ttm);

        return 0;
}

static void radeon_ttm_backend_destroy(struct ttm_tt *ttm)
{
        struct radeon_ttm_tt *gtt = (void *)ttm;

        ttm_dma_tt_fini(&gtt->ttm);
        kfree(gtt);
}

static struct ttm_backend_func radeon_backend_func = {
        .bind = &radeon_ttm_backend_bind,
        .unbind = &radeon_ttm_backend_unbind,
        .destroy = &radeon_ttm_backend_destroy,
};

static struct ttm_tt *radeon_ttm_tt_create(struct ttm_bo_device *bdev,
                                    unsigned long size, uint32_t page_flags,
                                    struct page *dummy_read_page)
{
        struct radeon_device *rdev;
        struct radeon_ttm_tt *gtt;

        rdev = radeon_get_rdev(bdev);
#if IS_ENABLED(CONFIG_AGP)
        if (rdev->flags & RADEON_IS_AGP) {
                return ttm_agp_tt_create(bdev, rdev->ddev->agp->bridge,
                                         size, page_flags, dummy_read_page);
        }
#endif

        gtt = kzalloc(sizeof(struct radeon_ttm_tt), GFP_KERNEL);
        if (gtt == NULL) {
                return NULL;
        }
        gtt->ttm.ttm.func = &radeon_backend_func;
        gtt->rdev = rdev;
        if (ttm_dma_tt_init(&gtt->ttm, bdev, size, page_flags, dummy_read_page)) {
                kfree(gtt);
                return NULL;
        }
        return &gtt->ttm.ttm;
}

static struct radeon_ttm_tt *radeon_ttm_tt_to_gtt(struct ttm_tt *ttm)
{
        if (!ttm || ttm->func != &radeon_backend_func)
                return NULL;
        return (struct radeon_ttm_tt *)ttm;
}

static int radeon_ttm_tt_populate(struct ttm_tt *ttm)
{
        struct radeon_ttm_tt *gtt = radeon_ttm_tt_to_gtt(ttm);
        struct radeon_device *rdev;
        bool slave = !!(ttm->page_flags & TTM_PAGE_FLAG_SG);

        if (ttm->state != tt_unpopulated)
                return 0;

        if (gtt && gtt->userptr) {
                ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
                if (!ttm->sg)
                        return -ENOMEM;

                ttm->page_flags |= TTM_PAGE_FLAG_SG;
                ttm->state = tt_unbound;
                return 0;
        }

        if (slave && ttm->sg) {
                drm_prime_sg_to_page_addr_arrays(ttm->sg, ttm->pages,
                                                 gtt->ttm.dma_address, ttm->num_pages);
                ttm->state = tt_unbound;
                return 0;
        }

        rdev = radeon_get_rdev(ttm->bdev);
#if IS_ENABLED(CONFIG_AGP)
        if (rdev->flags & RADEON_IS_AGP) {
                return ttm_agp_tt_populate(ttm);
        }
#endif

#ifdef CONFIG_SWIOTLB
        if (swiotlb_nr_tbl()) {
                return ttm_dma_populate(&gtt->ttm, rdev->dev);
        }
#endif

        return ttm_populate_and_map_pages(rdev->dev, &gtt->ttm);
}

static void radeon_ttm_tt_unpopulate(struct ttm_tt *ttm)
{
        struct radeon_device *rdev;
        struct radeon_ttm_tt *gtt = radeon_ttm_tt_to_gtt(ttm);
        bool slave = !!(ttm->page_flags & TTM_PAGE_FLAG_SG);

        if (gtt && gtt->userptr) {
                kfree(ttm->sg);
                ttm->page_flags &= ~TTM_PAGE_FLAG_SG;
                return;
        }

        if (slave)
                return;

        rdev = radeon_get_rdev(ttm->bdev);
#if IS_ENABLED(CONFIG_AGP)
        if (rdev->flags & RADEON_IS_AGP) {
                ttm_agp_tt_unpopulate(ttm);
                return;
        }
#endif

#ifdef CONFIG_SWIOTLB
        if (swiotlb_nr_tbl()) {
                ttm_dma_unpopulate(&gtt->ttm, rdev->dev);
                return;
        }
#endif

        ttm_unmap_and_unpopulate_pages(rdev->dev, &gtt->ttm);
}

int radeon_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
                              uint32_t flags)
{
        struct radeon_ttm_tt *gtt = radeon_ttm_tt_to_gtt(ttm);

        if (gtt == NULL)
                return -EINVAL;

        gtt->userptr = addr;
        gtt->usermm = current->mm;
        gtt->userflags = flags;
        return 0;
}

bool radeon_ttm_tt_has_userptr(struct ttm_tt *ttm)
{
        struct radeon_ttm_tt *gtt = radeon_ttm_tt_to_gtt(ttm);

        if (gtt == NULL)
                return false;

        return !!gtt->userptr;
}

bool radeon_ttm_tt_is_readonly(struct ttm_tt *ttm)
{
        struct radeon_ttm_tt *gtt = radeon_ttm_tt_to_gtt(ttm);

        if (gtt == NULL)
                return false;

        return !!(gtt->userflags & RADEON_GEM_USERPTR_READONLY);
}

static struct ttm_bo_driver radeon_bo_driver = {
        .ttm_tt_create = &radeon_ttm_tt_create,
        .ttm_tt_populate = &radeon_ttm_tt_populate,
        .ttm_tt_unpopulate = &radeon_ttm_tt_unpopulate,
        .invalidate_caches = &radeon_invalidate_caches,
        .init_mem_type = &radeon_init_mem_type,
        .eviction_valuable = ttm_bo_eviction_valuable,
        .evict_flags = &radeon_evict_flags,
        .move = &radeon_bo_move,
        .verify_access = &radeon_verify_access,
        .move_notify = &radeon_bo_move_notify,
        .fault_reserve_notify = &radeon_bo_fault_reserve_notify,
        .io_mem_reserve = &radeon_ttm_io_mem_reserve,
        .io_mem_free = &radeon_ttm_io_mem_free,
        .io_mem_pfn = ttm_bo_default_io_mem_pfn,
};

int radeon_ttm_init(struct radeon_device *rdev)
{
        int r;

        r = radeon_ttm_global_init(rdev);
        if (r) {
                return r;
        }
        /* No others user of address space so set it to 0 */
        r = ttm_bo_device_init(&rdev->mman.bdev,
                               rdev->mman.bo_global_ref.ref.object,
                               &radeon_bo_driver,
                               rdev->ddev->anon_inode->i_mapping,
                               DRM_FILE_PAGE_OFFSET,
                               rdev->need_dma32);
        if (r) {
                DRM_ERROR("failed initializing buffer object driver(%d).\n", r);
                return r;
        }
        rdev->mman.initialized = true;
        r = ttm_bo_init_mm(&rdev->mman.bdev, TTM_PL_VRAM,
                                rdev->mc.real_vram_size >> PAGE_SHIFT);
        if (r) {
                DRM_ERROR("Failed initializing VRAM heap.\n");
                return r;
        }
        /* Change the size here instead of the init above so only lpfn is affected */
        radeon_ttm_set_active_vram_size(rdev, rdev->mc.visible_vram_size);

        r = radeon_bo_create(rdev, 256 * 1024, PAGE_SIZE, true,
                             RADEON_GEM_DOMAIN_VRAM, 0, NULL,
                             NULL, &rdev->stolen_vga_memory);
        if (r) {
                return r;
        }
        r = radeon_bo_reserve(rdev->stolen_vga_memory, false);
        if (r)
                return r;
        r = radeon_bo_pin(rdev->stolen_vga_memory, RADEON_GEM_DOMAIN_VRAM, NULL);
        radeon_bo_unreserve(rdev->stolen_vga_memory);
        if (r) {
                radeon_bo_unref(&rdev->stolen_vga_memory);
                return r;
        }
        DRM_INFO("radeon: %uM of VRAM memory ready\n",
                 (unsigned) (rdev->mc.real_vram_size / (1024 * 1024)));
        r = ttm_bo_init_mm(&rdev->mman.bdev, TTM_PL_TT,
                                rdev->mc.gtt_size >> PAGE_SHIFT);
        if (r) {
                DRM_ERROR("Failed initializing GTT heap.\n");
                return r;
        }
        DRM_INFO("radeon: %uM of GTT memory ready.\n",
                 (unsigned)(rdev->mc.gtt_size / (1024 * 1024)));

        r = radeon_ttm_debugfs_init(rdev);
        if (r) {
                DRM_ERROR("Failed to init debugfs\n");
                return r;
        }
        return 0;
}

void radeon_ttm_fini(struct radeon_device *rdev)
{
        int r;

        if (!rdev->mman.initialized)
                return;
        radeon_ttm_debugfs_fini(rdev);
        if (rdev->stolen_vga_memory) {
                r = radeon_bo_reserve(rdev->stolen_vga_memory, false);
                if (r == 0) {
                        radeon_bo_unpin(rdev->stolen_vga_memory);
                        radeon_bo_unreserve(rdev->stolen_vga_memory);
                }
                radeon_bo_unref(&rdev->stolen_vga_memory);
        }
        ttm_bo_clean_mm(&rdev->mman.bdev, TTM_PL_VRAM);
        ttm_bo_clean_mm(&rdev->mman.bdev, TTM_PL_TT);
        ttm_bo_device_release(&rdev->mman.bdev);
        radeon_gart_fini(rdev);
        radeon_ttm_global_fini(rdev);
        rdev->mman.initialized = false;
        DRM_INFO("radeon: ttm finalized\n");
}

/* this should only be called at bootup or when userspace
 * isn't running */
void radeon_ttm_set_active_vram_size(struct radeon_device *rdev, u64 size)
{
        struct ttm_mem_type_manager *man;

        if (!rdev->mman.initialized)
                return;

        man = &rdev->mman.bdev.man[TTM_PL_VRAM];
        /* this just adjusts TTM size idea, which sets lpfn to the correct value */
        man->size = size >> PAGE_SHIFT;
}

static struct vm_operations_struct radeon_ttm_vm_ops;
static const struct vm_operations_struct *ttm_vm_ops = NULL;

static int radeon_ttm_fault(struct vm_fault *vmf)
{
        struct ttm_buffer_object *bo;
        struct radeon_device *rdev;
        int r;

        bo = (struct ttm_buffer_object *)vmf->vma->vm_private_data;
        if (bo == NULL) {
                return VM_FAULT_NOPAGE;
        }
        rdev = radeon_get_rdev(bo->bdev);
        down_read(&rdev->pm.mclk_lock);
        r = ttm_vm_ops->fault(vmf);
        up_read(&rdev->pm.mclk_lock);
        return r;
}

int radeon_mmap(struct file *filp, struct vm_area_struct *vma)
{
        struct drm_file *file_priv;
        struct radeon_device *rdev;
        int r;

        if (unlikely(vma->vm_pgoff < DRM_FILE_PAGE_OFFSET)) {
                return -EINVAL;
        }

        file_priv = filp->private_data;
        rdev = file_priv->minor->dev->dev_private;
        if (rdev == NULL) {
                return -EINVAL;
        }
        r = ttm_bo_mmap(filp, vma, &rdev->mman.bdev);
        if (unlikely(r != 0)) {
                return r;
        }
        if (unlikely(ttm_vm_ops == NULL)) {
                ttm_vm_ops = vma->vm_ops;
                radeon_ttm_vm_ops = *ttm_vm_ops;
                radeon_ttm_vm_ops.fault = &radeon_ttm_fault;
        }
        vma->vm_ops = &radeon_ttm_vm_ops;
        return 0;
}

#if defined(CONFIG_DEBUG_FS)

static int radeon_mm_dump_table(struct seq_file *m, void *data)
{
        struct drm_info_node *node = (struct drm_info_node *)m->private;
        unsigned ttm_pl = *(int*)node->info_ent->data;
        struct drm_device *dev = node->minor->dev;
        struct radeon_device *rdev = dev->dev_private;
        struct ttm_mem_type_manager *man = &rdev->mman.bdev.man[ttm_pl];
        struct drm_printer p = drm_seq_file_printer(m);

        man->func->debug(man, &p);
        return 0;
}


static int ttm_pl_vram = TTM_PL_VRAM;
static int ttm_pl_tt = TTM_PL_TT;

static struct drm_info_list radeon_ttm_debugfs_list[] = {
        {"radeon_vram_mm", radeon_mm_dump_table, 0, &ttm_pl_vram},
        {"radeon_gtt_mm", radeon_mm_dump_table, 0, &ttm_pl_tt},
        {"ttm_page_pool", ttm_page_alloc_debugfs, 0, NULL},
#ifdef CONFIG_SWIOTLB
        {"ttm_dma_page_pool", ttm_dma_page_alloc_debugfs, 0, NULL}
#endif
};

static int radeon_ttm_vram_open(struct inode *inode, struct file *filep)
{
        struct radeon_device *rdev = inode->i_private;
        i_size_write(inode, rdev->mc.mc_vram_size);
        filep->private_data = inode->i_private;
        return 0;
}

static ssize_t radeon_ttm_vram_read(struct file *f, char __user *buf,
                                    size_t size, loff_t *pos)
{
        struct radeon_device *rdev = f->private_data;
        ssize_t result = 0;
        int r;

        if (size & 0x3 || *pos & 0x3)
                return -EINVAL;

        while (size) {
                unsigned long flags;
                uint32_t value;

                if (*pos >= rdev->mc.mc_vram_size)
                        return result;

                spin_lock_irqsave(&rdev->mmio_idx_lock, flags);
                WREG32(RADEON_MM_INDEX, ((uint32_t)*pos) | 0x80000000);
                if (rdev->family >= CHIP_CEDAR)
                        WREG32(EVERGREEN_MM_INDEX_HI, *pos >> 31);
                value = RREG32(RADEON_MM_DATA);
                spin_unlock_irqrestore(&rdev->mmio_idx_lock, flags);

                r = put_user(value, (uint32_t *)buf);
                if (r)
                        return r;

                result += 4;
                buf += 4;
                *pos += 4;
                size -= 4;
        }

        return result;
}

static const struct file_operations radeon_ttm_vram_fops = {
        .owner = THIS_MODULE,
        .open = radeon_ttm_vram_open,
        .read = radeon_ttm_vram_read,
        .llseek = default_llseek
};

static int radeon_ttm_gtt_open(struct inode *inode, struct file *filep)
{
        struct radeon_device *rdev = inode->i_private;
        i_size_write(inode, rdev->mc.gtt_size);
        filep->private_data = inode->i_private;
        return 0;
}

static ssize_t radeon_ttm_gtt_read(struct file *f, char __user *buf,
                                   size_t size, loff_t *pos)
{
        struct radeon_device *rdev = f->private_data;
        ssize_t result = 0;
        int r;

        while (size) {
                loff_t p = *pos / PAGE_SIZE;
                unsigned off = *pos & ~PAGE_MASK;
                size_t cur_size = min_t(size_t, size, PAGE_SIZE - off);
                struct page *page;
                void *ptr;

                if (p >= rdev->gart.num_cpu_pages)
                        return result;

                page = rdev->gart.pages[p];
                if (page) {
                        ptr = kmap(page);
                        ptr += off;

                        r = copy_to_user(buf, ptr, cur_size);
                        kunmap(rdev->gart.pages[p]);
                } else
                        r = clear_user(buf, cur_size);

                if (r)
                        return -EFAULT;

                result += cur_size;
                buf += cur_size;
                *pos += cur_size;
                size -= cur_size;
        }

        return result;
}

static const struct file_operations radeon_ttm_gtt_fops = {
        .owner = THIS_MODULE,
        .open = radeon_ttm_gtt_open,
        .read = radeon_ttm_gtt_read,
        .llseek = default_llseek
};

#endif

static int radeon_ttm_debugfs_init(struct radeon_device *rdev)
{
#if defined(CONFIG_DEBUG_FS)
        unsigned count;

        struct drm_minor *minor = rdev->ddev->primary;
        struct dentry *ent, *root = minor->debugfs_root;

        ent = debugfs_create_file("radeon_vram", S_IFREG | S_IRUGO, root,
                                  rdev, &radeon_ttm_vram_fops);
        if (IS_ERR(ent))
                return PTR_ERR(ent);
        rdev->mman.vram = ent;

        ent = debugfs_create_file("radeon_gtt", S_IFREG | S_IRUGO, root,
                                  rdev, &radeon_ttm_gtt_fops);
        if (IS_ERR(ent))
                return PTR_ERR(ent);
        rdev->mman.gtt = ent;

        count = ARRAY_SIZE(radeon_ttm_debugfs_list);

#ifdef CONFIG_SWIOTLB
        if (!swiotlb_nr_tbl())
                --count;
#endif

        return radeon_debugfs_add_files(rdev, radeon_ttm_debugfs_list, count);
#else

        return 0;
#endif
}

static void radeon_ttm_debugfs_fini(struct radeon_device *rdev)
{
#if defined(CONFIG_DEBUG_FS)

        debugfs_remove(rdev->mman.vram);
        rdev->mman.vram = NULL;

        debugfs_remove(rdev->mman.gtt);
        rdev->mman.gtt = NULL;
#endif
}