/*
 * 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 <linux/dma-mapping.h>
#include <linux/iommu.h>
#include <linux/pagemap.h>
#include <linux/sched/task.h>
#include <linux/sched/mm.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/dma-buf.h>
#include <linux/sizes.h>
#include <linux/module.h>

#include <drm/drm_drv.h>
#include <drm/ttm/ttm_bo.h>
#include <drm/ttm/ttm_placement.h>
#include <drm/ttm/ttm_range_manager.h>
#include <drm/ttm/ttm_tt.h>

#include <drm/amdgpu_drm.h>

#include "amdgpu.h"
#include "amdgpu_object.h"
#include "amdgpu_trace.h"
#include "amdgpu_amdkfd.h"
#include "amdgpu_sdma.h"
#include "amdgpu_ras.h"
#include "amdgpu_hmm.h"
#include "amdgpu_atomfirmware.h"
#include "amdgpu_res_cursor.h"
#include "bif/bif_4_1_d.h"

MODULE_IMPORT_NS("DMA_BUF");

#define AMDGPU_TTM_VRAM_MAX_DW_READ     ((size_t)128)

static int amdgpu_ttm_backend_bind(struct ttm_device *bdev,
                                   struct ttm_tt *ttm,
                                   struct ttm_resource *bo_mem);
static void amdgpu_ttm_backend_unbind(struct ttm_device *bdev,
                                      struct ttm_tt *ttm);

static int amdgpu_ttm_init_on_chip(struct amdgpu_device *adev,
                                    unsigned int type,
                                    uint64_t size_in_page)
{
        return ttm_range_man_init(&adev->mman.bdev, type,
                                  false, size_in_page);
}

/**
 * amdgpu_evict_flags - Compute placement flags
 *
 * @bo: The buffer object to evict
 * @placement: Possible destination(s) for evicted BO
 *
 * Fill in placement data when ttm_bo_evict() is called
 */
static void amdgpu_evict_flags(struct ttm_buffer_object *bo,
                                struct ttm_placement *placement)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
        struct amdgpu_bo *abo;
        static const struct ttm_place placements = {
                .fpfn = 0,
                .lpfn = 0,
                .mem_type = TTM_PL_SYSTEM,
                .flags = 0
        };

        /* Don't handle scatter gather BOs */
        if (bo->type == ttm_bo_type_sg) {
                placement->num_placement = 0;
                return;
        }

        /* Object isn't an AMDGPU object so ignore */
        if (!amdgpu_bo_is_amdgpu_bo(bo)) {
                placement->placement = &placements;
                placement->num_placement = 1;
                return;
        }

        abo = ttm_to_amdgpu_bo(bo);
        if (abo->flags & AMDGPU_GEM_CREATE_DISCARDABLE) {
                placement->num_placement = 0;
                return;
        }

        switch (bo->resource->mem_type) {
        case AMDGPU_PL_GDS:
        case AMDGPU_PL_GWS:
        case AMDGPU_PL_OA:
        case AMDGPU_PL_DOORBELL:
        case AMDGPU_PL_MMIO_REMAP:
                placement->num_placement = 0;
                return;

        case TTM_PL_VRAM:
                if (!adev->mman.buffer_funcs_enabled) {
                        /* Move to system memory */
                        amdgpu_bo_placement_from_domain(abo, AMDGPU_GEM_DOMAIN_CPU);

                } else if (!amdgpu_gmc_vram_full_visible(&adev->gmc) &&
                           !(abo->flags & AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED) &&
                           amdgpu_res_cpu_visible(adev, bo->resource)) {

                        /* 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
                         */
                        amdgpu_bo_placement_from_domain(abo, AMDGPU_GEM_DOMAIN_VRAM |
                                                        AMDGPU_GEM_DOMAIN_GTT |
                                                        AMDGPU_GEM_DOMAIN_CPU);
                        abo->placements[0].fpfn = adev->gmc.visible_vram_size >> PAGE_SHIFT;
                        abo->placements[0].lpfn = 0;
                        abo->placements[0].flags |= TTM_PL_FLAG_DESIRED;
                } else {
                        /* Move to GTT memory */
                        amdgpu_bo_placement_from_domain(abo, AMDGPU_GEM_DOMAIN_GTT |
                                                        AMDGPU_GEM_DOMAIN_CPU);
                }
                break;
        case TTM_PL_TT:
        case AMDGPU_PL_PREEMPT:
        default:
                amdgpu_bo_placement_from_domain(abo, AMDGPU_GEM_DOMAIN_CPU);
                break;
        }
        *placement = abo->placement;
}

static struct dma_fence *
amdgpu_ttm_job_submit(struct amdgpu_device *adev, struct amdgpu_job *job, u32 num_dw)
{
        struct amdgpu_ring *ring;

        ring = adev->mman.buffer_funcs_ring;
        amdgpu_ring_pad_ib(ring, &job->ibs[0]);
        WARN_ON(job->ibs[0].length_dw > num_dw);

        return amdgpu_job_submit(job);
}

/**
 * amdgpu_ttm_map_buffer - Map memory into the GART windows
 * @entity: entity to run the window setup job
 * @bo: buffer object to map
 * @mem: memory object to map
 * @mm_cur: range to map
 * @window: which GART window to use
 * @tmz: if we should setup a TMZ enabled mapping
 * @size: in number of bytes to map, out number of bytes mapped
 * @addr: resulting address inside the MC address space
 *
 * Setup one of the GART windows to access a specific piece of memory or return
 * the physical address for local memory.
 */
static int amdgpu_ttm_map_buffer(struct amdgpu_ttm_buffer_entity *entity,
                                 struct ttm_buffer_object *bo,
                                 struct ttm_resource *mem,
                                 struct amdgpu_res_cursor *mm_cur,
                                 unsigned int window,
                                 bool tmz, uint64_t *size, uint64_t *addr)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
        unsigned int offset, num_pages, num_dw, num_bytes;
        uint64_t src_addr, dst_addr;
        struct amdgpu_job *job;
        void *cpu_addr;
        uint64_t flags;
        int r;

        BUG_ON(adev->mman.buffer_funcs->copy_max_bytes <
               AMDGPU_GTT_MAX_TRANSFER_SIZE * 8);

        if (WARN_ON(mem->mem_type == AMDGPU_PL_PREEMPT))
                return -EINVAL;

        /* Map only what can't be accessed directly */
        if (!tmz && mem->start != AMDGPU_BO_INVALID_OFFSET) {
                *addr = amdgpu_ttm_domain_start(adev, mem->mem_type) +
                        mm_cur->start;
                return 0;
        }


        /*
         * If start begins at an offset inside the page, then adjust the size
         * and addr accordingly
         */
        offset = mm_cur->start & ~PAGE_MASK;

        num_pages = PFN_UP(*size + offset);
        num_pages = min_t(uint32_t, num_pages, AMDGPU_GTT_MAX_TRANSFER_SIZE);

        *size = min(*size, (uint64_t)num_pages * PAGE_SIZE - offset);

        *addr = adev->gmc.gart_start;
        *addr += (u64)window * AMDGPU_GTT_MAX_TRANSFER_SIZE *
                AMDGPU_GPU_PAGE_SIZE;
        *addr += offset;

        num_dw = ALIGN(adev->mman.buffer_funcs->copy_num_dw, 8);
        num_bytes = num_pages * 8 * AMDGPU_GPU_PAGES_IN_CPU_PAGE;

        r = amdgpu_job_alloc_with_ib(adev, &entity->base,
                                     AMDGPU_FENCE_OWNER_UNDEFINED,
                                     num_dw * 4 + num_bytes,
                                     AMDGPU_IB_POOL_DELAYED, &job,
                                     AMDGPU_KERNEL_JOB_ID_TTM_MAP_BUFFER);
        if (r)
                return r;

        src_addr = num_dw * 4;
        src_addr += job->ibs[0].gpu_addr;

        dst_addr = amdgpu_bo_gpu_offset(adev->gart.bo);
        dst_addr += window * AMDGPU_GTT_MAX_TRANSFER_SIZE * 8;
        amdgpu_emit_copy_buffer(adev, &job->ibs[0], src_addr,
                                dst_addr, num_bytes, 0);

        flags = amdgpu_ttm_tt_pte_flags(adev, bo->ttm, mem);
        if (tmz)
                flags |= AMDGPU_PTE_TMZ;

        cpu_addr = &job->ibs[0].ptr[num_dw];

        if (mem->mem_type == TTM_PL_TT) {
                dma_addr_t *dma_addr;

                dma_addr = &bo->ttm->dma_address[mm_cur->start >> PAGE_SHIFT];
                amdgpu_gart_map(adev, 0, num_pages, dma_addr, flags, cpu_addr);
        } else {
                u64 pa = mm_cur->start + adev->vm_manager.vram_base_offset;

                amdgpu_gart_map_vram_range(adev, pa, 0, num_pages, flags, cpu_addr);
        }

        dma_fence_put(amdgpu_ttm_job_submit(adev, job, num_dw));
        return 0;
}

/**
 * amdgpu_ttm_copy_mem_to_mem - Helper function for copy
 * @adev: amdgpu device
 * @entity: entity to run the jobs
 * @src: buffer/address where to read from
 * @dst: buffer/address where to write to
 * @size: number of bytes to copy
 * @tmz: if a secure copy should be used
 * @resv: resv object to sync to
 * @f: Returns the last fence if multiple jobs are submitted.
 *
 * The function copies @size bytes from {src->mem + src->offset} to
 * {dst->mem + dst->offset}. src->bo and dst->bo could be same BO for a
 * move and different for a BO to BO copy.
 *
 */
__attribute__((nonnull))
static int amdgpu_ttm_copy_mem_to_mem(struct amdgpu_device *adev,
                                      struct amdgpu_ttm_buffer_entity *entity,
                                      const struct amdgpu_copy_mem *src,
                                      const struct amdgpu_copy_mem *dst,
                                      uint64_t size, bool tmz,
                                      struct dma_resv *resv,
                                      struct dma_fence **f)
{
        struct amdgpu_res_cursor src_mm, dst_mm;
        struct dma_fence *fence = NULL;
        int r = 0;
        uint32_t copy_flags = 0;
        struct amdgpu_bo *abo_src, *abo_dst;

        if (!adev->mman.buffer_funcs_enabled) {
                dev_err(adev->dev,
                        "Trying to move memory with ring turned off.\n");
                return -EINVAL;
        }

        amdgpu_res_first(src->mem, src->offset, size, &src_mm);
        amdgpu_res_first(dst->mem, dst->offset, size, &dst_mm);

        mutex_lock(&adev->mman.gtt_window_lock);
        while (src_mm.remaining) {
                uint64_t from, to, cur_size, tiling_flags;
                uint32_t num_type, data_format, max_com, write_compress_disable;
                struct dma_fence *next;

                /* Never copy more than 256MiB at once to avoid a timeout */
                cur_size = min3(src_mm.size, dst_mm.size, 256ULL << 20);

                /* Map src to window 0 and dst to window 1. */
                r = amdgpu_ttm_map_buffer(entity, src->bo, src->mem, &src_mm,
                                          0, tmz, &cur_size, &from);
                if (r)
                        goto error;

                r = amdgpu_ttm_map_buffer(entity, dst->bo, dst->mem, &dst_mm,
                                          1, tmz, &cur_size, &to);
                if (r)
                        goto error;

                abo_src = ttm_to_amdgpu_bo(src->bo);
                abo_dst = ttm_to_amdgpu_bo(dst->bo);
                if (tmz)
                        copy_flags |= AMDGPU_COPY_FLAGS_TMZ;
                if ((abo_src->flags & AMDGPU_GEM_CREATE_GFX12_DCC) &&
                    (abo_src->tbo.resource->mem_type == TTM_PL_VRAM))
                        copy_flags |= AMDGPU_COPY_FLAGS_READ_DECOMPRESSED;
                if ((abo_dst->flags & AMDGPU_GEM_CREATE_GFX12_DCC) &&
                    (dst->mem->mem_type == TTM_PL_VRAM)) {
                        copy_flags |= AMDGPU_COPY_FLAGS_WRITE_COMPRESSED;
                        amdgpu_bo_get_tiling_flags(abo_dst, &tiling_flags);
                        max_com = AMDGPU_TILING_GET(tiling_flags, GFX12_DCC_MAX_COMPRESSED_BLOCK);
                        num_type = AMDGPU_TILING_GET(tiling_flags, GFX12_DCC_NUMBER_TYPE);
                        data_format = AMDGPU_TILING_GET(tiling_flags, GFX12_DCC_DATA_FORMAT);
                        write_compress_disable =
                                AMDGPU_TILING_GET(tiling_flags, GFX12_DCC_WRITE_COMPRESS_DISABLE);
                        copy_flags |= (AMDGPU_COPY_FLAGS_SET(MAX_COMPRESSED, max_com) |
                                       AMDGPU_COPY_FLAGS_SET(NUMBER_TYPE, num_type) |
                                       AMDGPU_COPY_FLAGS_SET(DATA_FORMAT, data_format) |
                                       AMDGPU_COPY_FLAGS_SET(WRITE_COMPRESS_DISABLE,
                                                             write_compress_disable));
                }

                r = amdgpu_copy_buffer(adev, entity, from, to, cur_size, resv,
                                       &next, true, copy_flags);
                if (r)
                        goto error;

                dma_fence_put(fence);
                fence = next;

                amdgpu_res_next(&src_mm, cur_size);
                amdgpu_res_next(&dst_mm, cur_size);
        }
error:
        mutex_unlock(&adev->mman.gtt_window_lock);
        *f = fence;
        return r;
}

/*
 * amdgpu_move_blit - Copy an entire buffer to another buffer
 *
 * This is a helper called by amdgpu_bo_move() and amdgpu_move_vram_ram() to
 * help move buffers to and from VRAM.
 */
static int amdgpu_move_blit(struct ttm_buffer_object *bo,
                            bool evict,
                            struct ttm_resource *new_mem,
                            struct ttm_resource *old_mem)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
        struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
        struct amdgpu_copy_mem src, dst;
        struct dma_fence *fence = NULL;
        int r;

        src.bo = bo;
        dst.bo = bo;
        src.mem = old_mem;
        dst.mem = new_mem;
        src.offset = 0;
        dst.offset = 0;

        r = amdgpu_ttm_copy_mem_to_mem(adev,
                                       &adev->mman.move_entity,
                                       &src, &dst,
                                       new_mem->size,
                                       amdgpu_bo_encrypted(abo),
                                       bo->base.resv, &fence);
        if (r)
                goto error;

        /* clear the space being freed */
        if (old_mem->mem_type == TTM_PL_VRAM &&
            (abo->flags & AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE)) {
                struct dma_fence *wipe_fence = NULL;

                r = amdgpu_fill_buffer(&adev->mman.move_entity,
                                       abo, 0, NULL, &wipe_fence,
                                       AMDGPU_KERNEL_JOB_ID_MOVE_BLIT);
                if (r) {
                        goto error;
                } else if (wipe_fence) {
                        amdgpu_vram_mgr_set_cleared(bo->resource);
                        dma_fence_put(fence);
                        fence = wipe_fence;
                }
        }

        /* Always block for VM page tables before committing the new location */
        if (bo->type == ttm_bo_type_kernel)
                r = ttm_bo_move_accel_cleanup(bo, fence, true, false, new_mem);
        else
                r = ttm_bo_move_accel_cleanup(bo, fence, evict, true, new_mem);
        dma_fence_put(fence);
        return r;

error:
        if (fence)
                dma_fence_wait(fence, false);
        dma_fence_put(fence);
        return r;
}

/**
 * amdgpu_res_cpu_visible - Check that resource can be accessed by CPU
 * @adev: amdgpu device
 * @res: the resource to check
 *
 * Returns: true if the full resource is CPU visible, false otherwise.
 */
bool amdgpu_res_cpu_visible(struct amdgpu_device *adev,
                            struct ttm_resource *res)
{
        struct amdgpu_res_cursor cursor;

        if (!res)
                return false;

        if (res->mem_type == TTM_PL_SYSTEM || res->mem_type == TTM_PL_TT ||
            res->mem_type == AMDGPU_PL_PREEMPT || res->mem_type == AMDGPU_PL_DOORBELL ||
            res->mem_type == AMDGPU_PL_MMIO_REMAP)
                return true;

        if (res->mem_type != TTM_PL_VRAM)
                return false;

        amdgpu_res_first(res, 0, res->size, &cursor);
        while (cursor.remaining) {
                if ((cursor.start + cursor.size) > adev->gmc.visible_vram_size)
                        return false;
                amdgpu_res_next(&cursor, cursor.size);
        }

        return true;
}

/*
 * amdgpu_res_copyable - Check that memory can be accessed by ttm_bo_move_memcpy
 *
 * Called by amdgpu_bo_move()
 */
static bool amdgpu_res_copyable(struct amdgpu_device *adev,
                                struct ttm_resource *mem)
{
        if (!amdgpu_res_cpu_visible(adev, mem))
                return false;

        /* ttm_resource_ioremap only supports contiguous memory */
        if (mem->mem_type == TTM_PL_VRAM &&
            !(mem->placement & TTM_PL_FLAG_CONTIGUOUS))
                return false;

        return true;
}

/*
 * amdgpu_bo_move - Move a buffer object to a new memory location
 *
 * Called by ttm_bo_handle_move_mem()
 */
static int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
                          struct ttm_operation_ctx *ctx,
                          struct ttm_resource *new_mem,
                          struct ttm_place *hop)
{
        struct amdgpu_device *adev;
        struct amdgpu_bo *abo;
        struct ttm_resource *old_mem = bo->resource;
        int r;

        if (new_mem->mem_type == TTM_PL_TT ||
            new_mem->mem_type == AMDGPU_PL_PREEMPT) {
                r = amdgpu_ttm_backend_bind(bo->bdev, bo->ttm, new_mem);
                if (r)
                        return r;
        }

        abo = ttm_to_amdgpu_bo(bo);
        adev = amdgpu_ttm_adev(bo->bdev);

        if (!old_mem || (old_mem->mem_type == TTM_PL_SYSTEM &&
                         bo->ttm == NULL)) {
                amdgpu_bo_move_notify(bo, evict, new_mem);
                ttm_bo_move_null(bo, new_mem);
                return 0;
        }
        if (old_mem->mem_type == TTM_PL_SYSTEM &&
            (new_mem->mem_type == TTM_PL_TT ||
             new_mem->mem_type == AMDGPU_PL_PREEMPT)) {
                amdgpu_bo_move_notify(bo, evict, new_mem);
                ttm_bo_move_null(bo, new_mem);
                return 0;
        }
        if ((old_mem->mem_type == TTM_PL_TT ||
             old_mem->mem_type == AMDGPU_PL_PREEMPT) &&
            new_mem->mem_type == TTM_PL_SYSTEM) {
                r = ttm_bo_wait_ctx(bo, ctx);
                if (r)
                        return r;

                amdgpu_ttm_backend_unbind(bo->bdev, bo->ttm);
                amdgpu_bo_move_notify(bo, evict, new_mem);
                ttm_resource_free(bo, &bo->resource);
                ttm_bo_assign_mem(bo, new_mem);
                return 0;
        }

        if (old_mem->mem_type == AMDGPU_PL_GDS ||
            old_mem->mem_type == AMDGPU_PL_GWS ||
            old_mem->mem_type == AMDGPU_PL_OA ||
            old_mem->mem_type == AMDGPU_PL_DOORBELL ||
            old_mem->mem_type == AMDGPU_PL_MMIO_REMAP ||
            new_mem->mem_type == AMDGPU_PL_GDS ||
            new_mem->mem_type == AMDGPU_PL_GWS ||
            new_mem->mem_type == AMDGPU_PL_OA ||
            new_mem->mem_type == AMDGPU_PL_DOORBELL ||
            new_mem->mem_type == AMDGPU_PL_MMIO_REMAP) {
                /* Nothing to save here */
                amdgpu_bo_move_notify(bo, evict, new_mem);
                ttm_bo_move_null(bo, new_mem);
                return 0;
        }

        if (bo->type == ttm_bo_type_device &&
            new_mem->mem_type == TTM_PL_VRAM &&
            old_mem->mem_type != TTM_PL_VRAM) {
                /* amdgpu_bo_fault_reserve_notify will re-set this if the CPU
                 * accesses the BO after it's moved.
                 */
                abo->flags &= ~AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED;
        }

        if (adev->mman.buffer_funcs_enabled &&
            ((old_mem->mem_type == TTM_PL_SYSTEM &&
              new_mem->mem_type == TTM_PL_VRAM) ||
             (old_mem->mem_type == TTM_PL_VRAM &&
              new_mem->mem_type == TTM_PL_SYSTEM))) {
                hop->fpfn = 0;
                hop->lpfn = 0;
                hop->mem_type = TTM_PL_TT;
                hop->flags = TTM_PL_FLAG_TEMPORARY;
                return -EMULTIHOP;
        }

        amdgpu_bo_move_notify(bo, evict, new_mem);
        if (adev->mman.buffer_funcs_enabled)
                r = amdgpu_move_blit(bo, evict, new_mem, old_mem);
        else
                r = -ENODEV;

        if (r) {
                /* Check that all memory is CPU accessible */
                if (!amdgpu_res_copyable(adev, old_mem) ||
                    !amdgpu_res_copyable(adev, new_mem)) {
                        pr_err("Move buffer fallback to memcpy unavailable\n");
                        return r;
                }

                r = ttm_bo_move_memcpy(bo, ctx, new_mem);
                if (r)
                        return r;
        }

        /* update statistics after the move */
        if (evict)
                atomic64_inc(&adev->num_evictions);
        atomic64_add(bo->base.size, &adev->num_bytes_moved);
        return 0;
}

/*
 * amdgpu_ttm_io_mem_reserve - Reserve a block of memory during a fault
 *
 * Called by ttm_mem_io_reserve() ultimately via ttm_bo_vm_fault()
 */
static int amdgpu_ttm_io_mem_reserve(struct ttm_device *bdev,
                                     struct ttm_resource *mem)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);

        switch (mem->mem_type) {
        case TTM_PL_SYSTEM:
                /* system memory */
                return 0;
        case TTM_PL_TT:
        case AMDGPU_PL_PREEMPT:
                break;
        case TTM_PL_VRAM:
                mem->bus.offset = mem->start << PAGE_SHIFT;

                if (adev->mman.aper_base_kaddr &&
                    mem->placement & TTM_PL_FLAG_CONTIGUOUS)
                        mem->bus.addr = (u8 *)adev->mman.aper_base_kaddr +
                                        mem->bus.offset;

                mem->bus.offset += adev->gmc.aper_base;
                mem->bus.is_iomem = true;
                break;
        case AMDGPU_PL_DOORBELL:
                mem->bus.offset = mem->start << PAGE_SHIFT;
                mem->bus.offset += adev->doorbell.base;
                mem->bus.is_iomem = true;
                mem->bus.caching = ttm_uncached;
                break;
        case AMDGPU_PL_MMIO_REMAP:
                mem->bus.offset = mem->start << PAGE_SHIFT;
                mem->bus.offset += adev->rmmio_remap.bus_addr;
                mem->bus.is_iomem = true;
                mem->bus.caching = ttm_uncached;
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

static unsigned long amdgpu_ttm_io_mem_pfn(struct ttm_buffer_object *bo,
                                           unsigned long page_offset)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
        struct amdgpu_res_cursor cursor;

        amdgpu_res_first(bo->resource, (u64)page_offset << PAGE_SHIFT, 0,
                         &cursor);

        if (bo->resource->mem_type == AMDGPU_PL_DOORBELL)
                return ((uint64_t)(adev->doorbell.base + cursor.start)) >> PAGE_SHIFT;
        else if (bo->resource->mem_type == AMDGPU_PL_MMIO_REMAP)
                return ((uint64_t)(adev->rmmio_remap.bus_addr + cursor.start)) >> PAGE_SHIFT;

        return (adev->gmc.aper_base + cursor.start) >> PAGE_SHIFT;
}

/**
 * amdgpu_ttm_domain_start - Returns GPU start address
 * @adev: amdgpu device object
 * @type: type of the memory
 *
 * Returns:
 * GPU start address of a memory domain
 */

uint64_t amdgpu_ttm_domain_start(struct amdgpu_device *adev, uint32_t type)
{
        switch (type) {
        case TTM_PL_TT:
                return adev->gmc.gart_start;
        case TTM_PL_VRAM:
                return adev->gmc.vram_start;
        }

        return 0;
}

/*
 * TTM backend functions.
 */
struct amdgpu_ttm_tt {
        struct ttm_tt   ttm;
        struct drm_gem_object   *gobj;
        u64                     offset;
        uint64_t                userptr;
        struct task_struct      *usertask;
        uint32_t                userflags;
        bool                    bound;
        int32_t                 pool_id;
};

#define ttm_to_amdgpu_ttm_tt(ptr)       container_of(ptr, struct amdgpu_ttm_tt, ttm)

#ifdef CONFIG_DRM_AMDGPU_USERPTR
/*
 * amdgpu_ttm_tt_get_user_pages - get device accessible pages that back user
 * memory and start HMM tracking CPU page table update
 *
 * Calling function must call amdgpu_ttm_tt_userptr_range_done() once and only
 * once afterwards to stop HMM tracking. Its the caller responsibility to ensure
 * that range is a valid memory and it is freed too.
 */
int amdgpu_ttm_tt_get_user_pages(struct amdgpu_bo *bo,
                                 struct amdgpu_hmm_range *range)
{
        struct ttm_tt *ttm = bo->tbo.ttm;
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);
        unsigned long start = gtt->userptr;
        struct vm_area_struct *vma;
        struct mm_struct *mm;
        bool readonly;
        int r = 0;

        mm = bo->notifier.mm;
        if (unlikely(!mm)) {
                DRM_DEBUG_DRIVER("BO is not registered?\n");
                return -EFAULT;
        }

        if (!mmget_not_zero(mm)) /* Happens during process shutdown */
                return -ESRCH;

        mmap_read_lock(mm);
        vma = vma_lookup(mm, start);
        if (unlikely(!vma)) {
                r = -EFAULT;
                goto out_unlock;
        }
        if (unlikely((gtt->userflags & AMDGPU_GEM_USERPTR_ANONONLY) &&
                vma->vm_file)) {
                r = -EPERM;
                goto out_unlock;
        }

        readonly = amdgpu_ttm_tt_is_readonly(ttm);
        r = amdgpu_hmm_range_get_pages(&bo->notifier, start, ttm->num_pages,
                                       readonly, NULL, range);
out_unlock:
        mmap_read_unlock(mm);
        if (r)
                pr_debug("failed %d to get user pages 0x%lx\n", r, start);

        mmput(mm);

        return r;
}

#endif

/*
 * amdgpu_ttm_tt_set_user_pages - Copy pages in, putting old pages as necessary.
 *
 * Called by amdgpu_cs_list_validate(). This creates the page list
 * that backs user memory and will ultimately be mapped into the device
 * address space.
 */
void amdgpu_ttm_tt_set_user_pages(struct ttm_tt *ttm, struct amdgpu_hmm_range *range)
{
        unsigned long i;

        for (i = 0; i < ttm->num_pages; ++i)
                ttm->pages[i] = range ? hmm_pfn_to_page(range->hmm_range.hmm_pfns[i]) : NULL;
}

/*
 * amdgpu_ttm_tt_pin_userptr - prepare the sg table with the user pages
 *
 * Called by amdgpu_ttm_backend_bind()
 **/
static int amdgpu_ttm_tt_pin_userptr(struct ttm_device *bdev,
                                     struct ttm_tt *ttm)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);
        int write = !(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY);
        enum dma_data_direction direction = write ?
                DMA_BIDIRECTIONAL : DMA_TO_DEVICE;
        int r;

        /* Allocate an SG array and squash pages into it */
        r = sg_alloc_table_from_pages(ttm->sg, ttm->pages, ttm->num_pages, 0,
                                      (u64)ttm->num_pages << PAGE_SHIFT,
                                      GFP_KERNEL);
        if (r)
                goto release_sg;

        /* Map SG to device */
        r = dma_map_sgtable(adev->dev, ttm->sg, direction, 0);
        if (r)
                goto release_sg_table;

        /* convert SG to linear array of pages and dma addresses */
        drm_prime_sg_to_dma_addr_array(ttm->sg, gtt->ttm.dma_address,
                                       ttm->num_pages);

        return 0;

release_sg_table:
        sg_free_table(ttm->sg);
release_sg:
        kfree(ttm->sg);
        ttm->sg = NULL;
        return r;
}

/*
 * amdgpu_ttm_tt_unpin_userptr - Unpin and unmap userptr pages
 */
static void amdgpu_ttm_tt_unpin_userptr(struct ttm_device *bdev,
                                        struct ttm_tt *ttm)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);
        int write = !(gtt->userflags & AMDGPU_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 || !ttm->sg->sgl)
                return;

        /* unmap the pages mapped to the device */
        dma_unmap_sgtable(adev->dev, ttm->sg, direction, 0);
        sg_free_table(ttm->sg);
}

/*
 * total_pages is constructed as MQD0+CtrlStack0 + MQD1+CtrlStack1 + ...
 * MQDn+CtrlStackn where n is the number of XCCs per partition.
 * pages_per_xcc is the size of one MQD+CtrlStack. The first page is MQD
 * and uses memory type default, UC. The rest of pages_per_xcc are
 * Ctrl stack and modify their memory type to NC.
 */
static void amdgpu_ttm_gart_bind_gfx9_mqd(struct amdgpu_device *adev,
                                struct ttm_tt *ttm, uint64_t flags)
{
        struct amdgpu_ttm_tt *gtt = (void *)ttm;
        uint64_t total_pages = ttm->num_pages;
        int num_xcc = max(1U, adev->gfx.num_xcc_per_xcp);
        uint64_t page_idx, pages_per_xcc;
        int i;

        pages_per_xcc = total_pages;
        do_div(pages_per_xcc, num_xcc);

        for (i = 0, page_idx = 0; i < num_xcc; i++, page_idx += pages_per_xcc) {
                amdgpu_gart_map_gfx9_mqd(adev,
                                gtt->offset + (page_idx << PAGE_SHIFT),
                                pages_per_xcc, &gtt->ttm.dma_address[page_idx],
                                flags);
        }
}

static void amdgpu_ttm_gart_bind(struct amdgpu_device *adev,
                                 struct ttm_buffer_object *tbo,
                                 uint64_t flags)
{
        struct amdgpu_bo *abo = ttm_to_amdgpu_bo(tbo);
        struct ttm_tt *ttm = tbo->ttm;
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);

        if (amdgpu_bo_encrypted(abo))
                flags |= AMDGPU_PTE_TMZ;

        if (abo->flags & AMDGPU_GEM_CREATE_CP_MQD_GFX9) {
                amdgpu_ttm_gart_bind_gfx9_mqd(adev, ttm, flags);
        } else {
                amdgpu_gart_bind(adev, gtt->offset, ttm->num_pages,
                                 gtt->ttm.dma_address, flags);
        }
        gtt->bound = true;
}

/*
 * amdgpu_ttm_backend_bind - Bind GTT memory
 *
 * Called by ttm_tt_bind() on behalf of ttm_bo_handle_move_mem().
 * This handles binding GTT memory to the device address space.
 */
static int amdgpu_ttm_backend_bind(struct ttm_device *bdev,
                                   struct ttm_tt *ttm,
                                   struct ttm_resource *bo_mem)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);
        uint64_t flags;
        int r;

        if (!bo_mem)
                return -EINVAL;

        if (gtt->bound)
                return 0;

        if (gtt->userptr) {
                r = amdgpu_ttm_tt_pin_userptr(bdev, ttm);
                if (r) {
                        dev_err(adev->dev, "failed to pin userptr\n");
                        return r;
                }
        } else if (ttm->page_flags & TTM_TT_FLAG_EXTERNAL) {
                if (!ttm->sg) {
                        struct dma_buf_attachment *attach;
                        struct sg_table *sgt;

                        attach = gtt->gobj->import_attach;
                        sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
                        if (IS_ERR(sgt))
                                return PTR_ERR(sgt);

                        ttm->sg = sgt;
                }

                drm_prime_sg_to_dma_addr_array(ttm->sg, gtt->ttm.dma_address,
                                               ttm->num_pages);
        }

        if (!ttm->num_pages) {
                WARN(1, "nothing to bind %u pages for mreg %p back %p!\n",
                     ttm->num_pages, bo_mem, ttm);
        }

        if (bo_mem->mem_type != TTM_PL_TT ||
            !amdgpu_gtt_mgr_has_gart_addr(bo_mem)) {
                gtt->offset = AMDGPU_BO_INVALID_OFFSET;
                return 0;
        }

        /* compute PTE flags relevant to this BO memory */
        flags = amdgpu_ttm_tt_pte_flags(adev, ttm, bo_mem);

        /* bind pages into GART page tables */
        gtt->offset = (u64)bo_mem->start << PAGE_SHIFT;
        amdgpu_gart_bind(adev, gtt->offset, ttm->num_pages,
                         gtt->ttm.dma_address, flags);
        gtt->bound = true;
        return 0;
}

/*
 * amdgpu_ttm_alloc_gart - Make sure buffer object is accessible either
 * through AGP or GART aperture.
 *
 * If bo is accessible through AGP aperture, then use AGP aperture
 * to access bo; otherwise allocate logical space in GART aperture
 * and map bo to GART aperture.
 */
int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
        struct ttm_operation_ctx ctx = { false, false };
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(bo->ttm);
        struct ttm_placement placement;
        struct ttm_place placements;
        struct ttm_resource *tmp;
        uint64_t addr, flags;
        int r;

        if (bo->resource->start != AMDGPU_BO_INVALID_OFFSET)
                return 0;

        addr = amdgpu_gmc_agp_addr(bo);
        if (addr != AMDGPU_BO_INVALID_OFFSET)
                return 0;

        /* allocate GART space */
        placement.num_placement = 1;
        placement.placement = &placements;
        placements.fpfn = 0;
        placements.lpfn = adev->gmc.gart_size >> PAGE_SHIFT;
        placements.mem_type = TTM_PL_TT;
        placements.flags = bo->resource->placement;

        r = ttm_bo_mem_space(bo, &placement, &tmp, &ctx);
        if (unlikely(r))
                return r;

        /* compute PTE flags for this buffer object */
        flags = amdgpu_ttm_tt_pte_flags(adev, bo->ttm, tmp);

        /* Bind pages */
        gtt->offset = (u64)tmp->start << PAGE_SHIFT;
        amdgpu_ttm_gart_bind(adev, bo, flags);
        amdgpu_gart_invalidate_tlb(adev);
        ttm_resource_free(bo, &bo->resource);
        ttm_bo_assign_mem(bo, tmp);

        return 0;
}

/*
 * amdgpu_ttm_recover_gart - Rebind GTT pages
 *
 * Called by amdgpu_gtt_mgr_recover() from amdgpu_device_reset() to
 * rebind GTT pages during a GPU reset.
 */
void amdgpu_ttm_recover_gart(struct ttm_buffer_object *tbo)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(tbo->bdev);
        uint64_t flags;

        if (!tbo->ttm)
                return;

        flags = amdgpu_ttm_tt_pte_flags(adev, tbo->ttm, tbo->resource);
        amdgpu_ttm_gart_bind(adev, tbo, flags);
}

/*
 * amdgpu_ttm_backend_unbind - Unbind GTT mapped pages
 *
 * Called by ttm_tt_unbind() on behalf of ttm_bo_move_ttm() and
 * ttm_tt_destroy().
 */
static void amdgpu_ttm_backend_unbind(struct ttm_device *bdev,
                                      struct ttm_tt *ttm)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);

        /* if the pages have userptr pinning then clear that first */
        if (gtt->userptr) {
                amdgpu_ttm_tt_unpin_userptr(bdev, ttm);
        } else if (ttm->sg && drm_gem_is_imported(gtt->gobj)) {
                struct dma_buf_attachment *attach;

                attach = gtt->gobj->import_attach;
                dma_buf_unmap_attachment(attach, ttm->sg, DMA_BIDIRECTIONAL);
                ttm->sg = NULL;
        }

        if (!gtt->bound)
                return;

        if (gtt->offset == AMDGPU_BO_INVALID_OFFSET)
                return;

        /* unbind shouldn't be done for GDS/GWS/OA in ttm_bo_clean_mm */
        amdgpu_gart_unbind(adev, gtt->offset, ttm->num_pages);
        gtt->bound = false;
}

static void amdgpu_ttm_backend_destroy(struct ttm_device *bdev,
                                       struct ttm_tt *ttm)
{
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);

        if (gtt->usertask)
                put_task_struct(gtt->usertask);

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

/**
 * amdgpu_ttm_mmio_remap_alloc_sgt - build an sg_table for MMIO_REMAP I/O aperture
 * @adev: amdgpu device providing the remap BAR base (adev->rmmio_remap.bus_addr)
 * @res:  TTM resource of the BO to export; expected to live in AMDGPU_PL_MMIO_REMAP
 * @dev:  importing device to map for (typically @attach->dev in dma-buf paths)
 * @dir:  DMA data direction for the importer (passed to dma_map_resource())
 * @sgt:  output; on success, set to a newly allocated sg_table describing the I/O span
 *
 * The HDP flush page (AMDGPU_PL_MMIO_REMAP) is a fixed hardware I/O window in a PCI
 * BAR—there are no struct pages to back it. Importers still need a DMA address list,
 * so we synthesize a minimal sg_table and populate it from dma_map_resource(), not
 * from pages. Using the common amdgpu_res_cursor walker keeps the offset/size math
 * consistent with other TTM/manager users.
 *
 * - @res is assumed to be a small, contiguous I/O region (typically a single 4 KiB
 *   page) in AMDGPU_PL_MMIO_REMAP. Callers should validate placement before calling.
 * - The sg entry is created with sg_set_page(sg, NULL, …) to reflect I/O space.
 * - The mapping uses DMA_ATTR_SKIP_CPU_SYNC because this is MMIO, not cacheable RAM.
 * - Peer reachability / p2pdma policy checks must be done by the caller.
 *
 * Return:
 * * 0 on success, with *@sgt set to a valid table that must be freed via
 *   amdgpu_ttm_mmio_remap_free_sgt().
 * * -ENOMEM if allocation of the sg_table fails.
 * * -EIO if dma_map_resource() fails.
 *
 */
int amdgpu_ttm_mmio_remap_alloc_sgt(struct amdgpu_device *adev,
                                    struct ttm_resource *res,
                                    struct device *dev,
                                    enum dma_data_direction dir,
                                    struct sg_table **sgt)
{
        struct amdgpu_res_cursor cur;
        dma_addr_t dma;
        resource_size_t phys;
        struct scatterlist *sg;
        int r;

        /* Walk the resource once; MMIO_REMAP is expected to be contiguous+small. */
        amdgpu_res_first(res, 0, res->size, &cur);

        /* Translate byte offset in the remap window into a host physical BAR address. */
        phys = adev->rmmio_remap.bus_addr + cur.start;

        /* Build a single-entry sg_table mapped as I/O (no struct page backing). */
        *sgt = kzalloc_obj(**sgt);
        if (!*sgt)
                return -ENOMEM;
        r = sg_alloc_table(*sgt, 1, GFP_KERNEL);
        if (r) {
                kfree(*sgt);
                return r;
        }
        sg = (*sgt)->sgl;
        sg_set_page(sg, NULL, cur.size, 0);  /* WHY: I/O space → no pages */

        dma = dma_map_resource(dev, phys, cur.size, dir, DMA_ATTR_SKIP_CPU_SYNC);
        if (dma_mapping_error(dev, dma)) {
                sg_free_table(*sgt);
                kfree(*sgt);
                return -EIO;
        }
        sg_dma_address(sg) = dma;
        sg_dma_len(sg) = cur.size;
        return 0;
}

void amdgpu_ttm_mmio_remap_free_sgt(struct device *dev,
                                    enum dma_data_direction dir,
                                    struct sg_table *sgt)
{
        struct scatterlist *sg = sgt->sgl;

        dma_unmap_resource(dev, sg_dma_address(sg), sg_dma_len(sg),
                           dir, DMA_ATTR_SKIP_CPU_SYNC);
        sg_free_table(sgt);
        kfree(sgt);
}

/**
 * amdgpu_ttm_tt_create - Create a ttm_tt object for a given BO
 *
 * @bo: The buffer object to create a GTT ttm_tt object around
 * @page_flags: Page flags to be added to the ttm_tt object
 *
 * Called by ttm_tt_create().
 */
static struct ttm_tt *amdgpu_ttm_tt_create(struct ttm_buffer_object *bo,
                                           uint32_t page_flags)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
        struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
        struct amdgpu_ttm_tt *gtt;
        enum ttm_caching caching;

        gtt = kzalloc_obj(struct amdgpu_ttm_tt);
        if (!gtt)
                return NULL;

        gtt->gobj = &bo->base;
        if (adev->gmc.mem_partitions && abo->xcp_id >= 0)
                gtt->pool_id = KFD_XCP_MEM_ID(adev, abo->xcp_id);
        else
                gtt->pool_id = abo->xcp_id;

        if (abo->flags & AMDGPU_GEM_CREATE_CPU_GTT_USWC)
                caching = ttm_write_combined;
        else
                caching = ttm_cached;

        /* allocate space for the uninitialized page entries */
        if (ttm_sg_tt_init(&gtt->ttm, bo, page_flags, caching)) {
                kfree(gtt);
                return NULL;
        }
        return &gtt->ttm;
}

/*
 * amdgpu_ttm_tt_populate - Map GTT pages visible to the device
 *
 * Map the pages of a ttm_tt object to an address space visible
 * to the underlying device.
 */
static int amdgpu_ttm_tt_populate(struct ttm_device *bdev,
                                  struct ttm_tt *ttm,
                                  struct ttm_operation_ctx *ctx)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bdev);
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);
        struct ttm_pool *pool;
        pgoff_t i;
        int ret;

        /* user pages are bound by amdgpu_ttm_tt_pin_userptr() */
        if (gtt->userptr) {
                ttm->sg = kzalloc_obj(struct sg_table);
                if (!ttm->sg)
                        return -ENOMEM;
                return 0;
        }

        if (ttm->page_flags & TTM_TT_FLAG_EXTERNAL)
                return 0;

        if (adev->mman.ttm_pools && gtt->pool_id >= 0)
                pool = &adev->mman.ttm_pools[gtt->pool_id];
        else
                pool = &adev->mman.bdev.pool;
        ret = ttm_pool_alloc(pool, ttm, ctx);
        if (ret)
                return ret;

        for (i = 0; i < ttm->num_pages; ++i)
                ttm->pages[i]->mapping = bdev->dev_mapping;

        return 0;
}

/*
 * amdgpu_ttm_tt_unpopulate - unmap GTT pages and unpopulate page arrays
 *
 * Unmaps pages of a ttm_tt object from the device address space and
 * unpopulates the page array backing it.
 */
static void amdgpu_ttm_tt_unpopulate(struct ttm_device *bdev,
                                     struct ttm_tt *ttm)
{
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);
        struct amdgpu_device *adev;
        struct ttm_pool *pool;
        pgoff_t i;

        amdgpu_ttm_backend_unbind(bdev, ttm);

        if (gtt->userptr) {
                amdgpu_ttm_tt_set_user_pages(ttm, NULL);
                kfree(ttm->sg);
                ttm->sg = NULL;
                return;
        }

        if (ttm->page_flags & TTM_TT_FLAG_EXTERNAL)
                return;

        for (i = 0; i < ttm->num_pages; ++i)
                ttm->pages[i]->mapping = NULL;

        adev = amdgpu_ttm_adev(bdev);

        if (adev->mman.ttm_pools && gtt->pool_id >= 0)
                pool = &adev->mman.ttm_pools[gtt->pool_id];
        else
                pool = &adev->mman.bdev.pool;

        return ttm_pool_free(pool, ttm);
}

/**
 * amdgpu_ttm_tt_get_userptr - Return the userptr GTT ttm_tt for the current
 * task
 *
 * @tbo: The ttm_buffer_object that contains the userptr
 * @user_addr:  The returned value
 */
int amdgpu_ttm_tt_get_userptr(const struct ttm_buffer_object *tbo,
                              uint64_t *user_addr)
{
        struct amdgpu_ttm_tt *gtt;

        if (!tbo->ttm)
                return -EINVAL;

        gtt = (void *)tbo->ttm;
        *user_addr = gtt->userptr;
        return 0;
}

/**
 * amdgpu_ttm_tt_set_userptr - Initialize userptr GTT ttm_tt for the current
 * task
 *
 * @bo: The ttm_buffer_object to bind this userptr to
 * @addr:  The address in the current tasks VM space to use
 * @flags: Requirements of userptr object.
 *
 * Called by amdgpu_gem_userptr_ioctl() and kfd_ioctl_alloc_memory_of_gpu() to
 * bind userptr pages to current task and by kfd_ioctl_acquire_vm() to
 * initialize GPU VM for a KFD process.
 */
int amdgpu_ttm_tt_set_userptr(struct ttm_buffer_object *bo,
                              uint64_t addr, uint32_t flags)
{
        struct amdgpu_ttm_tt *gtt;

        if (!bo->ttm) {
                /* TODO: We want a separate TTM object type for userptrs */
                bo->ttm = amdgpu_ttm_tt_create(bo, 0);
                if (bo->ttm == NULL)
                        return -ENOMEM;
        }

        /* Set TTM_TT_FLAG_EXTERNAL before populate but after create. */
        bo->ttm->page_flags |= TTM_TT_FLAG_EXTERNAL;

        gtt = ttm_to_amdgpu_ttm_tt(bo->ttm);
        gtt->userptr = addr;
        gtt->userflags = flags;

        if (gtt->usertask)
                put_task_struct(gtt->usertask);
        gtt->usertask = current->group_leader;
        get_task_struct(gtt->usertask);

        return 0;
}

/*
 * amdgpu_ttm_tt_get_usermm - Return memory manager for ttm_tt object
 */
struct mm_struct *amdgpu_ttm_tt_get_usermm(struct ttm_tt *ttm)
{
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);

        if (gtt == NULL)
                return NULL;

        if (gtt->usertask == NULL)
                return NULL;

        return gtt->usertask->mm;
}

/*
 * amdgpu_ttm_tt_affect_userptr - Determine if a ttm_tt object lays inside an
 * address range for the current task.
 *
 */
bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
                                  unsigned long end, unsigned long *userptr)
{
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);
        unsigned long size;

        if (gtt == NULL || !gtt->userptr)
                return false;

        /* Return false if no part of the ttm_tt object lies within
         * the range
         */
        size = (unsigned long)gtt->ttm.num_pages * PAGE_SIZE;
        if (gtt->userptr > end || gtt->userptr + size <= start)
                return false;

        if (userptr)
                *userptr = gtt->userptr;
        return true;
}

/*
 * amdgpu_ttm_tt_is_userptr - Have the pages backing by userptr?
 */
bool amdgpu_ttm_tt_is_userptr(struct ttm_tt *ttm)
{
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);

        if (gtt == NULL || !gtt->userptr)
                return false;

        return true;
}

/*
 * amdgpu_ttm_tt_is_readonly - Is the ttm_tt object read only?
 */
bool amdgpu_ttm_tt_is_readonly(struct ttm_tt *ttm)
{
        struct amdgpu_ttm_tt *gtt = ttm_to_amdgpu_ttm_tt(ttm);

        if (gtt == NULL)
                return false;

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

/**
 * amdgpu_ttm_tt_pde_flags - Compute PDE flags for ttm_tt object
 *
 * @ttm: The ttm_tt object to compute the flags for
 * @mem: The memory registry backing this ttm_tt object
 *
 * Figure out the flags to use for a VM PDE (Page Directory Entry).
 */
uint64_t amdgpu_ttm_tt_pde_flags(struct ttm_tt *ttm, struct ttm_resource *mem)
{
        uint64_t flags = 0;

        if (mem && mem->mem_type != TTM_PL_SYSTEM)
                flags |= AMDGPU_PTE_VALID;

        if (mem && (mem->mem_type == TTM_PL_TT ||
                    mem->mem_type == AMDGPU_PL_DOORBELL ||
                    mem->mem_type == AMDGPU_PL_PREEMPT ||
                    mem->mem_type == AMDGPU_PL_MMIO_REMAP)) {
                flags |= AMDGPU_PTE_SYSTEM;

                if (ttm && ttm->caching == ttm_cached)
                        flags |= AMDGPU_PTE_SNOOPED;
        }

        if (mem && mem->mem_type == TTM_PL_VRAM &&
                        mem->bus.caching == ttm_cached)
                flags |= AMDGPU_PTE_SNOOPED;

        return flags;
}

/**
 * amdgpu_ttm_tt_pte_flags - Compute PTE flags for ttm_tt object
 *
 * @adev: amdgpu_device pointer
 * @ttm: The ttm_tt object to compute the flags for
 * @mem: The memory registry backing this ttm_tt object
 *
 * Figure out the flags to use for a VM PTE (Page Table Entry).
 */
uint64_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device *adev, struct ttm_tt *ttm,
                                 struct ttm_resource *mem)
{
        uint64_t flags = amdgpu_ttm_tt_pde_flags(ttm, mem);

        flags |= adev->gart.gart_pte_flags;
        flags |= AMDGPU_PTE_READABLE;

        if (!amdgpu_ttm_tt_is_readonly(ttm))
                flags |= AMDGPU_PTE_WRITEABLE;

        return flags;
}

/*
 * amdgpu_ttm_bo_eviction_valuable - Check to see if we can evict a buffer
 * object.
 *
 * Return true if eviction is sensible. Called by ttm_mem_evict_first() on
 * behalf of ttm_bo_mem_force_space() which tries to evict buffer objects until
 * it can find space for a new object and by ttm_bo_force_list_clean() which is
 * used to clean out a memory space.
 */
static bool amdgpu_ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
                                            const struct ttm_place *place)
{
        struct dma_resv_iter resv_cursor;
        struct dma_fence *f;

        if (!amdgpu_bo_is_amdgpu_bo(bo))
                return ttm_bo_eviction_valuable(bo, place);

        /* Swapout? */
        if (bo->resource->mem_type == TTM_PL_SYSTEM)
                return true;

        if (bo->type == ttm_bo_type_kernel &&
            !amdgpu_vm_evictable(ttm_to_amdgpu_bo(bo)))
                return false;

        /* If bo is a KFD BO, check if the bo belongs to the current process.
         * If true, then return false as any KFD process needs all its BOs to
         * be resident to run successfully
         */
        dma_resv_for_each_fence(&resv_cursor, bo->base.resv,
                                DMA_RESV_USAGE_BOOKKEEP, f) {
                if (amdkfd_fence_check_mm(f, current->mm) &&
                    !(place->flags & TTM_PL_FLAG_CONTIGUOUS))
                        return false;
        }

        /* Preemptible BOs don't own system resources managed by the
         * driver (pages, VRAM, GART space). They point to resources
         * owned by someone else (e.g. pageable memory in user mode
         * or a DMABuf). They are used in a preemptible context so we
         * can guarantee no deadlocks and good QoS in case of MMU
         * notifiers or DMABuf move notifiers from the resource owner.
         */
        if (bo->resource->mem_type == AMDGPU_PL_PREEMPT)
                return false;

        if (bo->resource->mem_type == TTM_PL_TT &&
            amdgpu_bo_encrypted(ttm_to_amdgpu_bo(bo)))
                return false;

        return ttm_bo_eviction_valuable(bo, place);
}

static void amdgpu_ttm_vram_mm_access(struct amdgpu_device *adev, loff_t pos,
                                      void *buf, size_t size, bool write)
{
        while (size) {
                uint64_t aligned_pos = ALIGN_DOWN(pos, 4);
                uint64_t bytes = 4 - (pos & 0x3);
                uint32_t shift = (pos & 0x3) * 8;
                uint32_t mask = 0xffffffff << shift;
                uint32_t value = 0;

                if (size < bytes) {
                        mask &= 0xffffffff >> (bytes - size) * 8;
                        bytes = size;
                }

                if (mask != 0xffffffff) {
                        amdgpu_device_mm_access(adev, aligned_pos, &value, 4, false);
                        if (write) {
                                value &= ~mask;
                                value |= (*(uint32_t *)buf << shift) & mask;
                                amdgpu_device_mm_access(adev, aligned_pos, &value, 4, true);
                        } else {
                                value = (value & mask) >> shift;
                                memcpy(buf, &value, bytes);
                        }
                } else {
                        amdgpu_device_mm_access(adev, aligned_pos, buf, 4, write);
                }

                pos += bytes;
                buf += bytes;
                size -= bytes;
        }
}

static int amdgpu_ttm_access_memory_sdma(struct ttm_buffer_object *bo,
                                        unsigned long offset, void *buf,
                                        int len, int write)
{
        struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
        struct amdgpu_device *adev = amdgpu_ttm_adev(abo->tbo.bdev);
        struct amdgpu_res_cursor src_mm;
        struct amdgpu_job *job;
        struct dma_fence *fence;
        uint64_t src_addr, dst_addr;
        unsigned int num_dw;
        int r, idx;

        if (len != PAGE_SIZE)
                return -EINVAL;

        if (!adev->mman.sdma_access_ptr)
                return -EACCES;

        if (!drm_dev_enter(adev_to_drm(adev), &idx))
                return -ENODEV;

        if (write)
                memcpy(adev->mman.sdma_access_ptr, buf, len);

        num_dw = ALIGN(adev->mman.buffer_funcs->copy_num_dw, 8);
        r = amdgpu_job_alloc_with_ib(adev, &adev->mman.default_entity.base,
                                     AMDGPU_FENCE_OWNER_UNDEFINED,
                                     num_dw * 4, AMDGPU_IB_POOL_DELAYED,
                                     &job,
                                     AMDGPU_KERNEL_JOB_ID_TTM_ACCESS_MEMORY_SDMA);
        if (r)
                goto out;

        mutex_lock(&adev->mman.gtt_window_lock);
        amdgpu_res_first(abo->tbo.resource, offset, len, &src_mm);
        src_addr = amdgpu_ttm_domain_start(adev, bo->resource->mem_type) +
                src_mm.start;
        dst_addr = amdgpu_bo_gpu_offset(adev->mman.sdma_access_bo);
        if (write)
                swap(src_addr, dst_addr);

        amdgpu_emit_copy_buffer(adev, &job->ibs[0], src_addr, dst_addr,
                                PAGE_SIZE, 0);

        fence = amdgpu_ttm_job_submit(adev, job, num_dw);
        mutex_unlock(&adev->mman.gtt_window_lock);

        if (!dma_fence_wait_timeout(fence, false, adev->sdma_timeout))
                r = -ETIMEDOUT;
        dma_fence_put(fence);

        if (!(r || write))
                memcpy(buf, adev->mman.sdma_access_ptr, len);
out:
        drm_dev_exit(idx);
        return r;
}

/**
 * amdgpu_ttm_access_memory - Read or Write memory that backs a buffer object.
 *
 * @bo:  The buffer object to read/write
 * @offset:  Offset into buffer object
 * @buf:  Secondary buffer to write/read from
 * @len: Length in bytes of access
 * @write:  true if writing
 *
 * This is used to access VRAM that backs a buffer object via MMIO
 * access for debugging purposes.
 */
static int amdgpu_ttm_access_memory(struct ttm_buffer_object *bo,
                                    unsigned long offset, void *buf, int len,
                                    int write)
{
        struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
        struct amdgpu_device *adev = amdgpu_ttm_adev(abo->tbo.bdev);
        struct amdgpu_res_cursor cursor;
        int ret = 0;

        if (bo->resource->mem_type != TTM_PL_VRAM)
                return -EIO;

        if (amdgpu_device_has_timeouts_enabled(adev) &&
                        !amdgpu_ttm_access_memory_sdma(bo, offset, buf, len, write))
                return len;

        amdgpu_res_first(bo->resource, offset, len, &cursor);
        while (cursor.remaining) {
                size_t count, size = cursor.size;
                loff_t pos = cursor.start;

                count = amdgpu_device_aper_access(adev, pos, buf, size, write);
                size -= count;
                if (size) {
                        /* using MM to access rest vram and handle un-aligned address */
                        pos += count;
                        buf += count;
                        amdgpu_ttm_vram_mm_access(adev, pos, buf, size, write);
                }

                ret += cursor.size;
                buf += cursor.size;
                amdgpu_res_next(&cursor, cursor.size);
        }

        return ret;
}

static void
amdgpu_bo_delete_mem_notify(struct ttm_buffer_object *bo)
{
        amdgpu_bo_move_notify(bo, false, NULL);
}

static struct ttm_device_funcs amdgpu_bo_driver = {
        .ttm_tt_create = &amdgpu_ttm_tt_create,
        .ttm_tt_populate = &amdgpu_ttm_tt_populate,
        .ttm_tt_unpopulate = &amdgpu_ttm_tt_unpopulate,
        .ttm_tt_destroy = &amdgpu_ttm_backend_destroy,
        .eviction_valuable = amdgpu_ttm_bo_eviction_valuable,
        .evict_flags = &amdgpu_evict_flags,
        .move = &amdgpu_bo_move,
        .delete_mem_notify = &amdgpu_bo_delete_mem_notify,
        .release_notify = &amdgpu_bo_release_notify,
        .io_mem_reserve = &amdgpu_ttm_io_mem_reserve,
        .io_mem_pfn = amdgpu_ttm_io_mem_pfn,
        .access_memory = &amdgpu_ttm_access_memory,
};

/*
 * Firmware Reservation functions
 */
/**
 * amdgpu_ttm_fw_reserve_vram_fini - free fw reserved vram
 *
 * @adev: amdgpu_device pointer
 *
 * free fw reserved vram if it has been reserved.
 */
static void amdgpu_ttm_fw_reserve_vram_fini(struct amdgpu_device *adev)
{
        amdgpu_bo_free_kernel(&adev->mman.fw_vram_usage_reserved_bo,
                NULL, &adev->mman.fw_vram_usage_va);
}

/*
 * Driver Reservation functions
 */
/**
 * amdgpu_ttm_drv_reserve_vram_fini - free drv reserved vram
 *
 * @adev: amdgpu_device pointer
 *
 * free drv reserved vram if it has been reserved.
 */
static void amdgpu_ttm_drv_reserve_vram_fini(struct amdgpu_device *adev)
{
        amdgpu_bo_free_kernel(&adev->mman.drv_vram_usage_reserved_bo,
                                                  NULL,
                                                  &adev->mman.drv_vram_usage_va);
}

/**
 * amdgpu_ttm_fw_reserve_vram_init - create bo vram reservation from fw
 *
 * @adev: amdgpu_device pointer
 *
 * create bo vram reservation from fw.
 */
static int amdgpu_ttm_fw_reserve_vram_init(struct amdgpu_device *adev)
{
        uint64_t vram_size = adev->gmc.visible_vram_size;

        adev->mman.fw_vram_usage_va = NULL;
        adev->mman.fw_vram_usage_reserved_bo = NULL;

        if (adev->mman.fw_vram_usage_size == 0 ||
            adev->mman.fw_vram_usage_size > vram_size)
                return 0;

        return amdgpu_bo_create_kernel_at(adev,
                                          adev->mman.fw_vram_usage_start_offset,
                                          adev->mman.fw_vram_usage_size,
                                          &adev->mman.fw_vram_usage_reserved_bo,
                                          &adev->mman.fw_vram_usage_va);
}

/**
 * amdgpu_ttm_drv_reserve_vram_init - create bo vram reservation from driver
 *
 * @adev: amdgpu_device pointer
 *
 * create bo vram reservation from drv.
 */
static int amdgpu_ttm_drv_reserve_vram_init(struct amdgpu_device *adev)
{
        u64 vram_size = adev->gmc.visible_vram_size;

        adev->mman.drv_vram_usage_va = NULL;
        adev->mman.drv_vram_usage_reserved_bo = NULL;

        if (adev->mman.drv_vram_usage_size == 0 ||
            adev->mman.drv_vram_usage_size > vram_size)
                return 0;

        return amdgpu_bo_create_kernel_at(adev,
                                          adev->mman.drv_vram_usage_start_offset,
                                          adev->mman.drv_vram_usage_size,
                                          &adev->mman.drv_vram_usage_reserved_bo,
                                          &adev->mman.drv_vram_usage_va);
}

/*
 * Memoy training reservation functions
 */

/**
 * amdgpu_ttm_training_reserve_vram_fini - free memory training reserved vram
 *
 * @adev: amdgpu_device pointer
 *
 * free memory training reserved vram if it has been reserved.
 */
static int amdgpu_ttm_training_reserve_vram_fini(struct amdgpu_device *adev)
{
        struct psp_memory_training_context *ctx = &adev->psp.mem_train_ctx;

        ctx->init = PSP_MEM_TRAIN_NOT_SUPPORT;
        amdgpu_bo_free_kernel(&ctx->c2p_bo, NULL, NULL);
        ctx->c2p_bo = NULL;

        return 0;
}

static void amdgpu_ttm_training_data_block_init(struct amdgpu_device *adev,
                                                uint32_t reserve_size)
{
        struct psp_memory_training_context *ctx = &adev->psp.mem_train_ctx;

        memset(ctx, 0, sizeof(*ctx));

        ctx->c2p_train_data_offset =
                ALIGN((adev->gmc.mc_vram_size - reserve_size - SZ_1M), SZ_1M);
        ctx->p2c_train_data_offset =
                (adev->gmc.mc_vram_size - GDDR6_MEM_TRAINING_OFFSET);
        ctx->train_data_size =
                GDDR6_MEM_TRAINING_DATA_SIZE_IN_BYTES;

        DRM_DEBUG("train_data_size:%llx,p2c_train_data_offset:%llx,c2p_train_data_offset:%llx.\n",
                        ctx->train_data_size,
                        ctx->p2c_train_data_offset,
                        ctx->c2p_train_data_offset);
}

/*
 * reserve TMR memory at the top of VRAM which holds
 * IP Discovery data and is protected by PSP.
 */
static int amdgpu_ttm_reserve_tmr(struct amdgpu_device *adev)
{
        struct psp_memory_training_context *ctx = &adev->psp.mem_train_ctx;
        bool mem_train_support = false;
        uint32_t reserve_size = 0;
        int ret;

        if (adev->bios && !amdgpu_sriov_vf(adev)) {
                if (amdgpu_atomfirmware_mem_training_supported(adev))
                        mem_train_support = true;
                else
                        DRM_DEBUG("memory training does not support!\n");
        }

        /*
         * Query reserved tmr size through atom firmwareinfo for Sienna_Cichlid and onwards for all
         * the use cases (IP discovery/G6 memory training/profiling/diagnostic data.etc)
         *
         * Otherwise, fallback to legacy approach to check and reserve tmr block for ip
         * discovery data and G6 memory training data respectively
         */
        if (adev->bios)
                reserve_size =
                        amdgpu_atomfirmware_get_fw_reserved_fb_size(adev);

        if (!adev->bios &&
            (amdgpu_ip_version(adev, GC_HWIP, 0) == IP_VERSION(9, 4, 3) ||
             amdgpu_ip_version(adev, GC_HWIP, 0) == IP_VERSION(9, 4, 4) ||
             amdgpu_ip_version(adev, GC_HWIP, 0) == IP_VERSION(9, 5, 0)))
                reserve_size = max(reserve_size, (uint32_t)280 << 20);
        else if (!adev->bios && 
                 amdgpu_ip_version(adev, GC_HWIP, 0) == IP_VERSION(12, 1, 0)) {
                if (hweight32(adev->aid_mask) == 1)
                        reserve_size = max(reserve_size, (uint32_t)128 << 20);
                else
                        reserve_size = max(reserve_size, (uint32_t)144 << 20);
        } else if (!reserve_size)
                reserve_size = DISCOVERY_TMR_OFFSET;

        if (mem_train_support) {
                /* reserve vram for mem train according to TMR location */
                amdgpu_ttm_training_data_block_init(adev, reserve_size);
                ret = amdgpu_bo_create_kernel_at(adev,
                                                 ctx->c2p_train_data_offset,
                                                 ctx->train_data_size,
                                                 &ctx->c2p_bo,
                                                 NULL);
                if (ret) {
                        dev_err(adev->dev, "alloc c2p_bo failed(%d)!\n", ret);
                        amdgpu_ttm_training_reserve_vram_fini(adev);
                        return ret;
                }
                ctx->init = PSP_MEM_TRAIN_RESERVE_SUCCESS;
        }

        ret = amdgpu_bo_create_kernel_at(
                adev, adev->gmc.real_vram_size - reserve_size, reserve_size,
                &adev->mman.fw_reserved_memory, NULL);
        if (ret) {
                dev_err(adev->dev, "alloc tmr failed(%d)!\n", ret);
                amdgpu_bo_free_kernel(&adev->mman.fw_reserved_memory, NULL,
                                      NULL);
                return ret;
        }

        return 0;
}

static int amdgpu_ttm_pools_init(struct amdgpu_device *adev)
{
        int i;

        if (!adev->gmc.is_app_apu || !adev->gmc.num_mem_partitions)
                return 0;

        adev->mman.ttm_pools = kzalloc_objs(*adev->mman.ttm_pools,
                                            adev->gmc.num_mem_partitions);
        if (!adev->mman.ttm_pools)
                return -ENOMEM;

        for (i = 0; i < adev->gmc.num_mem_partitions; i++) {
                ttm_pool_init(&adev->mman.ttm_pools[i], adev->dev,
                              adev->gmc.mem_partitions[i].numa.node,
                              TTM_ALLOCATION_POOL_BENEFICIAL_ORDER(get_order(SZ_2M)));
        }
        return 0;
}

static void amdgpu_ttm_pools_fini(struct amdgpu_device *adev)
{
        int i;

        if (!adev->gmc.is_app_apu || !adev->mman.ttm_pools)
                return;

        for (i = 0; i < adev->gmc.num_mem_partitions; i++)
                ttm_pool_fini(&adev->mman.ttm_pools[i]);

        kfree(adev->mman.ttm_pools);
        adev->mman.ttm_pools = NULL;
}

/**
 * amdgpu_ttm_mmio_remap_bo_init - Allocate the singleton MMIO_REMAP BO
 * @adev: amdgpu device
 *
 * Allocates a global BO with backing AMDGPU_PL_MMIO_REMAP when the
 * hardware exposes a remap base (adev->rmmio_remap.bus_addr) and the host
 * PAGE_SIZE is <= AMDGPU_GPU_PAGE_SIZE (4K). The BO is created as a regular
 * GEM object (amdgpu_bo_create).
 *
 * Return:
 *  * 0 on success or intentional skip (feature not present/unsupported)
 *  * negative errno on allocation failure
 */
static int amdgpu_ttm_alloc_mmio_remap_bo(struct amdgpu_device *adev)
{
        struct ttm_operation_ctx ctx = { false, false };
        struct ttm_placement placement;
        struct ttm_buffer_object *tbo;
        struct ttm_place placements;
        struct amdgpu_bo_param bp;
        struct ttm_resource *tmp;
        int r;

        /* Skip if HW doesn't expose remap, or if PAGE_SIZE > AMDGPU_GPU_PAGE_SIZE (4K). */
        if (!adev->rmmio_remap.bus_addr || PAGE_SIZE > AMDGPU_GPU_PAGE_SIZE)
                return 0;

        /*
         * Allocate a BO first and then move it to AMDGPU_PL_MMIO_REMAP.
         * The initial TTM resource assigned by amdgpu_bo_create() is
         * replaced below with a fixed MMIO_REMAP placement.
         */
        memset(&bp, 0, sizeof(bp));
        bp.type        = ttm_bo_type_device;
        bp.size        = AMDGPU_GPU_PAGE_SIZE;
        bp.byte_align  = AMDGPU_GPU_PAGE_SIZE;
        bp.domain      = 0;
        bp.flags       = 0;
        bp.resv        = NULL;
        bp.bo_ptr_size = sizeof(struct amdgpu_bo);
        r = amdgpu_bo_create(adev, &bp, &adev->rmmio_remap.bo);
        if (r)
                return r;

        r = amdgpu_bo_reserve(adev->rmmio_remap.bo, true);
        if (r)
                goto err_unref;

        tbo = &adev->rmmio_remap.bo->tbo;

        /*
         * MMIO_REMAP is a fixed I/O placement (AMDGPU_PL_MMIO_REMAP).
         */
        placement.num_placement = 1;
        placement.placement = &placements;
        placements.fpfn = 0;
        placements.lpfn = 0;
        placements.mem_type = AMDGPU_PL_MMIO_REMAP;
        placements.flags = 0;
        /* Force the BO into the fixed MMIO_REMAP placement */
        r = ttm_bo_mem_space(tbo, &placement, &tmp, &ctx);
        if (unlikely(r))
                goto err_unlock;

        ttm_resource_free(tbo, &tbo->resource);
        ttm_bo_assign_mem(tbo, tmp);
        ttm_bo_pin(tbo);

        amdgpu_bo_unreserve(adev->rmmio_remap.bo);
        return 0;

err_unlock:
        amdgpu_bo_unreserve(adev->rmmio_remap.bo);

err_unref:
        amdgpu_bo_unref(&adev->rmmio_remap.bo);
        adev->rmmio_remap.bo = NULL;
        return r;
}

/**
 * amdgpu_ttm_free_mmio_remap_bo - Free the singleton MMIO_REMAP BO
 * @adev: amdgpu device
 *
 * Frees the kernel-owned MMIO_REMAP BO if it was allocated by
 * amdgpu_ttm_mmio_remap_bo_init().
 */
static void amdgpu_ttm_free_mmio_remap_bo(struct amdgpu_device *adev)
{
        if (!adev->rmmio_remap.bo)
                return;

        if (!amdgpu_bo_reserve(adev->rmmio_remap.bo, true)) {
                ttm_bo_unpin(&adev->rmmio_remap.bo->tbo);
                amdgpu_bo_unreserve(adev->rmmio_remap.bo);
        }

    /*
     * At this point we rely on normal DRM teardown ordering:
     * no new user ioctls can access the global MMIO_REMAP BO
     * once TTM teardown begins.
     */
        amdgpu_bo_unref(&adev->rmmio_remap.bo);
        adev->rmmio_remap.bo = NULL;
}

/*
 * amdgpu_ttm_init - Init the memory management (ttm) as well as various
 * gtt/vram related fields.
 *
 * This initializes all of the memory space pools that the TTM layer
 * will need such as the GTT space (system memory mapped to the device),
 * VRAM (on-board memory), and on-chip memories (GDS, GWS, OA) which
 * can be mapped per VMID.
 */
int amdgpu_ttm_init(struct amdgpu_device *adev)
{
        uint64_t gtt_size;
        int r;

        mutex_init(&adev->mman.gtt_window_lock);

        dma_set_max_seg_size(adev->dev, UINT_MAX);
        /* No others user of address space so set it to 0 */
        r = ttm_device_init(&adev->mman.bdev, &amdgpu_bo_driver, adev->dev,
                               adev_to_drm(adev)->anon_inode->i_mapping,
                               adev_to_drm(adev)->vma_offset_manager,
                               (adev->need_swiotlb ?
                                TTM_ALLOCATION_POOL_USE_DMA_ALLOC : 0) |
                               (dma_addressing_limited(adev->dev) ?
                                TTM_ALLOCATION_POOL_USE_DMA32 : 0) |
                               TTM_ALLOCATION_POOL_BENEFICIAL_ORDER(get_order(SZ_2M)));
        if (r) {
                dev_err(adev->dev,
                        "failed initializing buffer object driver(%d).\n", r);
                return r;
        }

        r = amdgpu_ttm_pools_init(adev);
        if (r) {
                dev_err(adev->dev, "failed to init ttm pools(%d).\n", r);
                return r;
        }
        adev->mman.initialized = true;

        if (!adev->gmc.is_app_apu) {
                /* Initialize VRAM pool with all of VRAM divided into pages */
                r = amdgpu_vram_mgr_init(adev);
                if (r) {
                        dev_err(adev->dev, "Failed initializing VRAM heap.\n");
                        return r;
                }
        }

        /* Change the size here instead of the init above so only lpfn is affected */
        amdgpu_ttm_set_buffer_funcs_status(adev, false);
#ifdef CONFIG_64BIT
#ifdef CONFIG_X86
        if (adev->gmc.xgmi.connected_to_cpu)
                adev->mman.aper_base_kaddr = ioremap_cache(adev->gmc.aper_base,
                                adev->gmc.visible_vram_size);

        else if (adev->gmc.is_app_apu)
                DRM_DEBUG_DRIVER(
                        "No need to ioremap when real vram size is 0\n");
        else
#endif
                adev->mman.aper_base_kaddr = ioremap_wc(adev->gmc.aper_base,
                                adev->gmc.visible_vram_size);
#endif

        /*
         *The reserved vram for firmware must be pinned to the specified
         *place on the VRAM, so reserve it early.
         */
        r = amdgpu_ttm_fw_reserve_vram_init(adev);
        if (r)
                return r;

        /*
         * The reserved VRAM for the driver must be pinned to a specific
         * location in VRAM, so reserve it early.
         */
        r = amdgpu_ttm_drv_reserve_vram_init(adev);
        if (r)
                return r;

        /*
         * only NAVI10 and later ASICs support IP discovery.
         * If IP discovery is enabled, a block of memory should be
         * reserved for it.
         */
        if (adev->discovery.reserve_tmr) {
                r = amdgpu_ttm_reserve_tmr(adev);
                if (r)
                        return r;
        }

        /* allocate memory as required for VGA
         * This is used for VGA emulation and pre-OS scanout buffers to
         * avoid display artifacts while transitioning between pre-OS
         * and driver.
         */
        if (!adev->gmc.is_app_apu) {
                r = amdgpu_bo_create_kernel_at(adev, 0,
                                               adev->mman.stolen_vga_size,
                                               &adev->mman.stolen_vga_memory,
                                               NULL);
                if (r)
                        return r;

                r = amdgpu_bo_create_kernel_at(adev, adev->mman.stolen_vga_size,
                                               adev->mman.stolen_extended_size,
                                               &adev->mman.stolen_extended_memory,
                                               NULL);

                if (r)
                        return r;

                r = amdgpu_bo_create_kernel_at(adev,
                                               adev->mman.stolen_reserved_offset,
                                               adev->mman.stolen_reserved_size,
                                               &adev->mman.stolen_reserved_memory,
                                               NULL);
                if (r)
                        return r;
        } else {
                DRM_DEBUG_DRIVER("Skipped stolen memory reservation\n");
        }

        dev_info(adev->dev, " %uM of VRAM memory ready\n",
                 (unsigned int)(adev->gmc.real_vram_size / (1024 * 1024)));

        /* Compute GTT size, either based on TTM limit
         * or whatever the user passed on module init.
         */
        gtt_size = ttm_tt_pages_limit() << PAGE_SHIFT;
        if (amdgpu_gtt_size != -1) {
                uint64_t configured_size = (uint64_t)amdgpu_gtt_size << 20;

                drm_warn(&adev->ddev,
                        "Configuring gttsize via module parameter is deprecated, please use ttm.pages_limit\n");
                if (gtt_size != configured_size)
                        drm_warn(&adev->ddev,
                                "GTT size has been set as %llu but TTM size has been set as %llu, this is unusual\n",
                                configured_size, gtt_size);

                gtt_size = configured_size;
        }

        /* Initialize GTT memory pool */
        r = amdgpu_gtt_mgr_init(adev, gtt_size);
        if (r) {
                dev_err(adev->dev, "Failed initializing GTT heap.\n");
                return r;
        }
        dev_info(adev->dev, " %uM of GTT memory ready.\n",
                 (unsigned int)(gtt_size / (1024 * 1024)));

        if (adev->flags & AMD_IS_APU) {
                if (adev->gmc.real_vram_size < gtt_size)
                        adev->apu_prefer_gtt = true;
        }

        /* Initialize doorbell pool on PCI BAR */
        r = amdgpu_ttm_init_on_chip(adev, AMDGPU_PL_DOORBELL, adev->doorbell.size / PAGE_SIZE);
        if (r) {
                dev_err(adev->dev, "Failed initializing doorbell heap.\n");
                return r;
        }

        /* Create a boorbell page for kernel usages */
        r = amdgpu_doorbell_create_kernel_doorbells(adev);
        if (r) {
                dev_err(adev->dev, "Failed to initialize kernel doorbells.\n");
                return r;
        }

        /* Initialize MMIO-remap pool (single page 4K) */
        r = amdgpu_ttm_init_on_chip(adev, AMDGPU_PL_MMIO_REMAP, 1);
        if (r) {
                dev_err(adev->dev, "Failed initializing MMIO-remap heap.\n");
                return r;
        }

        /* Allocate the singleton MMIO_REMAP BO if supported */
        r = amdgpu_ttm_alloc_mmio_remap_bo(adev);
        if (r)
                return r;

        /* Initialize preemptible memory pool */
        r = amdgpu_preempt_mgr_init(adev);
        if (r) {
                dev_err(adev->dev, "Failed initializing PREEMPT heap.\n");
                return r;
        }

        /* Initialize various on-chip memory pools */
        r = amdgpu_ttm_init_on_chip(adev, AMDGPU_PL_GDS, adev->gds.gds_size);
        if (r) {
                dev_err(adev->dev, "Failed initializing GDS heap.\n");
                return r;
        }

        r = amdgpu_ttm_init_on_chip(adev, AMDGPU_PL_GWS, adev->gds.gws_size);
        if (r) {
                dev_err(adev->dev, "Failed initializing gws heap.\n");
                return r;
        }

        r = amdgpu_ttm_init_on_chip(adev, AMDGPU_PL_OA, adev->gds.oa_size);
        if (r) {
                dev_err(adev->dev, "Failed initializing oa heap.\n");
                return r;
        }
        if (amdgpu_bo_create_kernel(adev, PAGE_SIZE, PAGE_SIZE,
                                AMDGPU_GEM_DOMAIN_GTT,
                                &adev->mman.sdma_access_bo, NULL,
                                &adev->mman.sdma_access_ptr))
                drm_warn(adev_to_drm(adev),
                                "Debug VRAM access will use slowpath MM access\n");

        return 0;
}

/*
 * amdgpu_ttm_fini - De-initialize the TTM memory pools
 */
void amdgpu_ttm_fini(struct amdgpu_device *adev)
{
        int idx;

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

        amdgpu_ttm_pools_fini(adev);

        amdgpu_ttm_training_reserve_vram_fini(adev);
        /* return the stolen vga memory back to VRAM */
        if (!adev->gmc.is_app_apu) {
                amdgpu_bo_free_kernel(&adev->mman.stolen_vga_memory, NULL, NULL);
                amdgpu_bo_free_kernel(&adev->mman.stolen_extended_memory, NULL, NULL);
                /* return the FW reserved memory back to VRAM */
                amdgpu_bo_free_kernel(&adev->mman.fw_reserved_memory, NULL,
                                      NULL);
                amdgpu_bo_free_kernel(&adev->mman.fw_reserved_memory_extend, NULL,
                                      NULL);
                if (adev->mman.stolen_reserved_size)
                        amdgpu_bo_free_kernel(&adev->mman.stolen_reserved_memory,
                                              NULL, NULL);
        }
        amdgpu_bo_free_kernel(&adev->mman.sdma_access_bo, NULL,
                                        &adev->mman.sdma_access_ptr);

        amdgpu_ttm_free_mmio_remap_bo(adev);
        amdgpu_ttm_fw_reserve_vram_fini(adev);
        amdgpu_ttm_drv_reserve_vram_fini(adev);

        if (drm_dev_enter(adev_to_drm(adev), &idx)) {

                if (adev->mman.aper_base_kaddr)
                        iounmap(adev->mman.aper_base_kaddr);
                adev->mman.aper_base_kaddr = NULL;

                drm_dev_exit(idx);
        }

        if (!adev->gmc.is_app_apu)
                amdgpu_vram_mgr_fini(adev);
        amdgpu_gtt_mgr_fini(adev);
        amdgpu_preempt_mgr_fini(adev);
        amdgpu_doorbell_fini(adev);

        ttm_range_man_fini(&adev->mman.bdev, AMDGPU_PL_GDS);
        ttm_range_man_fini(&adev->mman.bdev, AMDGPU_PL_GWS);
        ttm_range_man_fini(&adev->mman.bdev, AMDGPU_PL_OA);
        ttm_range_man_fini(&adev->mman.bdev, AMDGPU_PL_DOORBELL);
        ttm_range_man_fini(&adev->mman.bdev, AMDGPU_PL_MMIO_REMAP);
        ttm_device_fini(&adev->mman.bdev);
        adev->mman.initialized = false;
        dev_info(adev->dev, " ttm finalized\n");
}

/**
 * amdgpu_ttm_set_buffer_funcs_status - enable/disable use of buffer functions
 *
 * @adev: amdgpu_device pointer
 * @enable: true when we can use buffer functions.
 *
 * Enable/disable use of buffer functions during suspend/resume. This should
 * only be called at bootup or when userspace isn't running.
 */
void amdgpu_ttm_set_buffer_funcs_status(struct amdgpu_device *adev, bool enable)
{
        struct ttm_resource_manager *man = ttm_manager_type(&adev->mman.bdev, TTM_PL_VRAM);
        uint64_t size;
        int r;

        if (!adev->mman.initialized || amdgpu_in_reset(adev) ||
            adev->mman.buffer_funcs_enabled == enable || adev->gmc.is_app_apu)
                return;

        if (enable) {
                struct amdgpu_ring *ring;
                struct drm_gpu_scheduler *sched;

                ring = adev->mman.buffer_funcs_ring;
                sched = &ring->sched;
                r = drm_sched_entity_init(&adev->mman.default_entity.base,
                                          DRM_SCHED_PRIORITY_KERNEL, &sched,
                                          1, NULL);
                if (r) {
                        dev_err(adev->dev,
                                "Failed setting up TTM BO move entity (%d)\n",
                                r);
                        return;
                }

                r = drm_sched_entity_init(&adev->mman.clear_entity.base,
                                          DRM_SCHED_PRIORITY_NORMAL, &sched,
                                          1, NULL);
                if (r) {
                        dev_err(adev->dev,
                                "Failed setting up TTM BO clear entity (%d)\n",
                                r);
                        goto error_free_entity;
                }

                r = drm_sched_entity_init(&adev->mman.move_entity.base,
                                          DRM_SCHED_PRIORITY_NORMAL, &sched,
                                          1, NULL);
                if (r) {
                        dev_err(adev->dev,
                                "Failed setting up TTM BO move entity (%d)\n",
                                r);
                        drm_sched_entity_destroy(&adev->mman.clear_entity.base);
                        goto error_free_entity;
                }
        } else {
                drm_sched_entity_destroy(&adev->mman.default_entity.base);
                drm_sched_entity_destroy(&adev->mman.clear_entity.base);
                drm_sched_entity_destroy(&adev->mman.move_entity.base);
                /* Drop all the old fences since re-creating the scheduler entities
                 * will allocate new contexts.
                 */
                ttm_resource_manager_cleanup(man);
        }

        /* this just adjusts TTM size idea, which sets lpfn to the correct value */
        if (enable)
                size = adev->gmc.real_vram_size;
        else
                size = adev->gmc.visible_vram_size;
        man->size = size;
        adev->mman.buffer_funcs_enabled = enable;

        return;

error_free_entity:
        drm_sched_entity_destroy(&adev->mman.default_entity.base);
}

static int amdgpu_ttm_prepare_job(struct amdgpu_device *adev,
                                  struct amdgpu_ttm_buffer_entity *entity,
                                  unsigned int num_dw,
                                  struct dma_resv *resv,
                                  bool vm_needs_flush,
                                  struct amdgpu_job **job,
                                  u64 k_job_id)
{
        enum amdgpu_ib_pool_type pool = AMDGPU_IB_POOL_DELAYED;
        int r;
        r = amdgpu_job_alloc_with_ib(adev, &entity->base,
                                     AMDGPU_FENCE_OWNER_UNDEFINED,
                                     num_dw * 4, pool, job, k_job_id);
        if (r)
                return r;

        if (vm_needs_flush) {
                (*job)->vm_pd_addr = amdgpu_gmc_pd_addr(adev->gmc.pdb0_bo ?
                                                        adev->gmc.pdb0_bo :
                                                        adev->gart.bo);
                (*job)->vm_needs_flush = true;
        }
        if (!resv)
                return 0;

        return drm_sched_job_add_resv_dependencies(&(*job)->base, resv,
                                                   DMA_RESV_USAGE_BOOKKEEP);
}

int amdgpu_copy_buffer(struct amdgpu_device *adev,
                       struct amdgpu_ttm_buffer_entity *entity,
                       uint64_t src_offset,
                       uint64_t dst_offset, uint32_t byte_count,
                       struct dma_resv *resv,
                       struct dma_fence **fence,
                       bool vm_needs_flush, uint32_t copy_flags)
{
        unsigned int num_loops, num_dw;
        struct amdgpu_ring *ring;
        struct amdgpu_job *job;
        uint32_t max_bytes;
        unsigned int i;
        int r;

        ring = adev->mman.buffer_funcs_ring;

        if (!ring->sched.ready) {
                dev_err(adev->dev,
                        "Trying to move memory with ring turned off.\n");
                return -EINVAL;
        }

        max_bytes = adev->mman.buffer_funcs->copy_max_bytes;
        num_loops = DIV_ROUND_UP(byte_count, max_bytes);
        num_dw = ALIGN(num_loops * adev->mman.buffer_funcs->copy_num_dw, 8);
        r = amdgpu_ttm_prepare_job(adev, entity, num_dw,
                                   resv, vm_needs_flush, &job,
                                   AMDGPU_KERNEL_JOB_ID_TTM_COPY_BUFFER);
        if (r)
                goto error_free;

        for (i = 0; i < num_loops; i++) {
                uint32_t cur_size_in_bytes = min(byte_count, max_bytes);

                amdgpu_emit_copy_buffer(adev, &job->ibs[0], src_offset,
                                        dst_offset, cur_size_in_bytes, copy_flags);
                src_offset += cur_size_in_bytes;
                dst_offset += cur_size_in_bytes;
                byte_count -= cur_size_in_bytes;
        }

        *fence = amdgpu_ttm_job_submit(adev, job, num_dw);

        return 0;

error_free:
        amdgpu_job_free(job);
        dev_err(adev->dev, "Error scheduling IBs (%d)\n", r);
        return r;
}

static int amdgpu_ttm_fill_mem(struct amdgpu_device *adev,
                               struct amdgpu_ttm_buffer_entity *entity,
                               uint32_t src_data,
                               uint64_t dst_addr, uint32_t byte_count,
                               struct dma_resv *resv,
                               struct dma_fence **fence,
                               bool vm_needs_flush,
                               u64 k_job_id)
{
        unsigned int num_loops, num_dw;
        struct amdgpu_job *job;
        uint32_t max_bytes;
        unsigned int i;
        int r;

        max_bytes = adev->mman.buffer_funcs->fill_max_bytes;
        num_loops = DIV_ROUND_UP_ULL(byte_count, max_bytes);
        num_dw = ALIGN(num_loops * adev->mman.buffer_funcs->fill_num_dw, 8);
        r = amdgpu_ttm_prepare_job(adev, entity, num_dw, resv,
                                   vm_needs_flush, &job, k_job_id);
        if (r)
                return r;

        for (i = 0; i < num_loops; i++) {
                uint32_t cur_size = min(byte_count, max_bytes);

                amdgpu_emit_fill_buffer(adev, &job->ibs[0], src_data, dst_addr,
                                        cur_size);

                dst_addr += cur_size;
                byte_count -= cur_size;
        }

        *fence = amdgpu_ttm_job_submit(adev, job, num_dw);
        return 0;
}

/**
 * amdgpu_ttm_clear_buffer - clear memory buffers
 * @bo: amdgpu buffer object
 * @resv: reservation object
 * @fence: dma_fence associated with the operation
 *
 * Clear the memory buffer resource.
 *
 * Returns:
 * 0 for success or a negative error code on failure.
 */
int amdgpu_ttm_clear_buffer(struct amdgpu_bo *bo,
                            struct dma_resv *resv,
                            struct dma_fence **fence)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
        struct amdgpu_res_cursor cursor;
        u64 addr;
        int r = 0;

        if (!adev->mman.buffer_funcs_enabled)
                return -EINVAL;

        if (!fence)
                return -EINVAL;

        *fence = dma_fence_get_stub();

        amdgpu_res_first(bo->tbo.resource, 0, amdgpu_bo_size(bo), &cursor);

        mutex_lock(&adev->mman.gtt_window_lock);
        while (cursor.remaining) {
                struct dma_fence *next = NULL;
                u64 size;

                if (amdgpu_res_cleared(&cursor)) {
                        amdgpu_res_next(&cursor, cursor.size);
                        continue;
                }

                /* Never clear more than 256MiB at once to avoid timeouts */
                size = min(cursor.size, 256ULL << 20);

                r = amdgpu_ttm_map_buffer(&adev->mman.clear_entity,
                                          &bo->tbo, bo->tbo.resource, &cursor,
                                          1, false, &size, &addr);
                if (r)
                        goto err;

                r = amdgpu_ttm_fill_mem(adev, &adev->mman.clear_entity, 0, addr, size, resv,
                                        &next, true,
                                        AMDGPU_KERNEL_JOB_ID_TTM_CLEAR_BUFFER);
                if (r)
                        goto err;

                dma_fence_put(*fence);
                *fence = next;

                amdgpu_res_next(&cursor, size);
        }
err:
        mutex_unlock(&adev->mman.gtt_window_lock);

        return r;
}

int amdgpu_fill_buffer(struct amdgpu_ttm_buffer_entity *entity,
                       struct amdgpu_bo *bo,
                       uint32_t src_data,
                       struct dma_resv *resv,
                       struct dma_fence **f,
                       u64 k_job_id)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
        struct dma_fence *fence = NULL;
        struct amdgpu_res_cursor dst;
        int r;

        if (!adev->mman.buffer_funcs_enabled) {
                dev_err(adev->dev,
                        "Trying to clear memory with ring turned off.\n");
                return -EINVAL;
        }

        amdgpu_res_first(bo->tbo.resource, 0, amdgpu_bo_size(bo), &dst);

        mutex_lock(&adev->mman.gtt_window_lock);
        while (dst.remaining) {
                struct dma_fence *next;
                uint64_t cur_size, to;

                /* Never fill more than 256MiB at once to avoid timeouts */
                cur_size = min(dst.size, 256ULL << 20);

                r = amdgpu_ttm_map_buffer(entity, &bo->tbo, bo->tbo.resource, &dst,
                                          1, false, &cur_size, &to);
                if (r)
                        goto error;

                r = amdgpu_ttm_fill_mem(adev, entity,
                                        src_data, to, cur_size, resv,
                                        &next, true, k_job_id);
                if (r)
                        goto error;

                dma_fence_put(fence);
                fence = next;

                amdgpu_res_next(&dst, cur_size);
        }
error:
        mutex_unlock(&adev->mman.gtt_window_lock);
        if (f)
                *f = dma_fence_get(fence);
        dma_fence_put(fence);
        return r;
}

/**
 * amdgpu_ttm_evict_resources - evict memory buffers
 * @adev: amdgpu device object
 * @mem_type: evicted BO's memory type
 *
 * Evicts all @mem_type buffers on the lru list of the memory type.
 *
 * Returns:
 * 0 for success or a negative error code on failure.
 */
int amdgpu_ttm_evict_resources(struct amdgpu_device *adev, int mem_type)
{
        struct ttm_resource_manager *man;

        switch (mem_type) {
        case TTM_PL_VRAM:
        case TTM_PL_TT:
        case AMDGPU_PL_GWS:
        case AMDGPU_PL_GDS:
        case AMDGPU_PL_OA:
                man = ttm_manager_type(&adev->mman.bdev, mem_type);
                break;
        default:
                dev_err(adev->dev, "Trying to evict invalid memory type\n");
                return -EINVAL;
        }

        return ttm_resource_manager_evict_all(&adev->mman.bdev, man);
}

#if defined(CONFIG_DEBUG_FS)

static int amdgpu_ttm_page_pool_show(struct seq_file *m, void *unused)
{
        struct amdgpu_device *adev = m->private;

        return ttm_pool_debugfs(&adev->mman.bdev.pool, m);
}

DEFINE_SHOW_ATTRIBUTE(amdgpu_ttm_page_pool);

/*
 * amdgpu_ttm_vram_read - Linear read access to VRAM
 *
 * Accesses VRAM via MMIO for debugging purposes.
 */
static ssize_t amdgpu_ttm_vram_read(struct file *f, char __user *buf,
                                    size_t size, loff_t *pos)
{
        struct amdgpu_device *adev = file_inode(f)->i_private;
        ssize_t result = 0;

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

        if (*pos >= adev->gmc.mc_vram_size)
                return -ENXIO;

        size = min(size, (size_t)(adev->gmc.mc_vram_size - *pos));
        while (size) {
                size_t bytes = min(size, AMDGPU_TTM_VRAM_MAX_DW_READ * 4);
                uint32_t value[AMDGPU_TTM_VRAM_MAX_DW_READ];

                amdgpu_device_vram_access(adev, *pos, value, bytes, false);
                if (copy_to_user(buf, value, bytes))
                        return -EFAULT;

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

        return result;
}

/*
 * amdgpu_ttm_vram_write - Linear write access to VRAM
 *
 * Accesses VRAM via MMIO for debugging purposes.
 */
static ssize_t amdgpu_ttm_vram_write(struct file *f, const char __user *buf,
                                    size_t size, loff_t *pos)
{
        struct amdgpu_device *adev = file_inode(f)->i_private;
        ssize_t result = 0;
        int r;

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

        if (*pos >= adev->gmc.mc_vram_size)
                return -ENXIO;

        while (size) {
                uint32_t value;

                if (*pos >= adev->gmc.mc_vram_size)
                        return result;

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

                amdgpu_device_mm_access(adev, *pos, &value, 4, true);

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

        return result;
}

static const struct file_operations amdgpu_ttm_vram_fops = {
        .owner = THIS_MODULE,
        .read = amdgpu_ttm_vram_read,
        .write = amdgpu_ttm_vram_write,
        .llseek = default_llseek,
};

/*
 * amdgpu_iomem_read - Virtual read access to GPU mapped memory
 *
 * This function is used to read memory that has been mapped to the
 * GPU and the known addresses are not physical addresses but instead
 * bus addresses (e.g., what you'd put in an IB or ring buffer).
 */
static ssize_t amdgpu_iomem_read(struct file *f, char __user *buf,
                                 size_t size, loff_t *pos)
{
        struct amdgpu_device *adev = file_inode(f)->i_private;
        struct iommu_domain *dom;
        ssize_t result = 0;
        int r;

        /* retrieve the IOMMU domain if any for this device */
        dom = iommu_get_domain_for_dev(adev->dev);

        while (size) {
                phys_addr_t addr = *pos & PAGE_MASK;
                loff_t off = *pos & ~PAGE_MASK;
                size_t bytes = PAGE_SIZE - off;
                unsigned long pfn;
                struct page *p;
                void *ptr;

                bytes = min(bytes, size);

                /* Translate the bus address to a physical address.  If
                 * the domain is NULL it means there is no IOMMU active
                 * and the address translation is the identity
                 */
                addr = dom ? iommu_iova_to_phys(dom, addr) : addr;

                pfn = addr >> PAGE_SHIFT;
                if (!pfn_valid(pfn))
                        return -EPERM;

                p = pfn_to_page(pfn);
                if (p->mapping != adev->mman.bdev.dev_mapping)
                        return -EPERM;

                ptr = kmap_local_page(p);
                r = copy_to_user(buf, ptr + off, bytes);
                kunmap_local(ptr);
                if (r)
                        return -EFAULT;

                size -= bytes;
                *pos += bytes;
                result += bytes;
        }

        return result;
}

/*
 * amdgpu_iomem_write - Virtual write access to GPU mapped memory
 *
 * This function is used to write memory that has been mapped to the
 * GPU and the known addresses are not physical addresses but instead
 * bus addresses (e.g., what you'd put in an IB or ring buffer).
 */
static ssize_t amdgpu_iomem_write(struct file *f, const char __user *buf,
                                 size_t size, loff_t *pos)
{
        struct amdgpu_device *adev = file_inode(f)->i_private;
        struct iommu_domain *dom;
        ssize_t result = 0;
        int r;

        dom = iommu_get_domain_for_dev(adev->dev);

        while (size) {
                phys_addr_t addr = *pos & PAGE_MASK;
                loff_t off = *pos & ~PAGE_MASK;
                size_t bytes = PAGE_SIZE - off;
                unsigned long pfn;
                struct page *p;
                void *ptr;

                bytes = min(bytes, size);

                addr = dom ? iommu_iova_to_phys(dom, addr) : addr;

                pfn = addr >> PAGE_SHIFT;
                if (!pfn_valid(pfn))
                        return -EPERM;

                p = pfn_to_page(pfn);
                if (p->mapping != adev->mman.bdev.dev_mapping)
                        return -EPERM;

                ptr = kmap_local_page(p);
                r = copy_from_user(ptr + off, buf, bytes);
                kunmap_local(ptr);
                if (r)
                        return -EFAULT;

                size -= bytes;
                *pos += bytes;
                result += bytes;
        }

        return result;
}

static const struct file_operations amdgpu_ttm_iomem_fops = {
        .owner = THIS_MODULE,
        .read = amdgpu_iomem_read,
        .write = amdgpu_iomem_write,
        .llseek = default_llseek
};

#endif

void amdgpu_ttm_debugfs_init(struct amdgpu_device *adev)
{
#if defined(CONFIG_DEBUG_FS)
        struct drm_minor *minor = adev_to_drm(adev)->primary;
        struct dentry *root = minor->debugfs_root;

        debugfs_create_file_size("amdgpu_vram", 0444, root, adev,
                                 &amdgpu_ttm_vram_fops, adev->gmc.mc_vram_size);
        debugfs_create_file("amdgpu_iomem", 0444, root, adev,
                            &amdgpu_ttm_iomem_fops);
        debugfs_create_file("ttm_page_pool", 0444, root, adev,
                            &amdgpu_ttm_page_pool_fops);
        ttm_resource_manager_create_debugfs(ttm_manager_type(&adev->mman.bdev,
                                                             TTM_PL_VRAM),
                                            root, "amdgpu_vram_mm");
        ttm_resource_manager_create_debugfs(ttm_manager_type(&adev->mman.bdev,
                                                             TTM_PL_TT),
                                            root, "amdgpu_gtt_mm");
        ttm_resource_manager_create_debugfs(ttm_manager_type(&adev->mman.bdev,
                                                             AMDGPU_PL_GDS),
                                            root, "amdgpu_gds_mm");
        ttm_resource_manager_create_debugfs(ttm_manager_type(&adev->mman.bdev,
                                                             AMDGPU_PL_GWS),
                                            root, "amdgpu_gws_mm");
        ttm_resource_manager_create_debugfs(ttm_manager_type(&adev->mman.bdev,
                                                             AMDGPU_PL_OA),
                                            root, "amdgpu_oa_mm");

#endif
}