/*
 * Copyright 2016 Advanced Micro Devices, Inc.
 *
 * 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, sublicense,
 * 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 above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * 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 NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
 *
 * Authors: Christian König
 */

#include <linux/dma-mapping.h>
#include <drm/ttm/ttm_range_manager.h>

#include "amdgpu.h"
#include "amdgpu_vm.h"
#include "amdgpu_res_cursor.h"
#include "amdgpu_atomfirmware.h"
#include "atom.h"

struct amdgpu_vram_reservation {
        struct list_head node;
        struct drm_mm_node mm_node;
};

static inline struct amdgpu_vram_mgr *
to_vram_mgr(struct ttm_resource_manager *man)
{
        return container_of(man, struct amdgpu_vram_mgr, manager);
}

static inline struct amdgpu_device *
to_amdgpu_device(struct amdgpu_vram_mgr *mgr)
{
        return container_of(mgr, struct amdgpu_device, mman.vram_mgr);
}

/**
 * DOC: mem_info_vram_total
 *
 * The amdgpu driver provides a sysfs API for reporting current total VRAM
 * available on the device
 * The file mem_info_vram_total is used for this and returns the total
 * amount of VRAM in bytes
 */
static ssize_t amdgpu_mem_info_vram_total_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct drm_device *ddev = dev_get_drvdata(dev);
        struct amdgpu_device *adev = drm_to_adev(ddev);

        return sysfs_emit(buf, "%llu\n", adev->gmc.real_vram_size);
}

/**
 * DOC: mem_info_vis_vram_total
 *
 * The amdgpu driver provides a sysfs API for reporting current total
 * visible VRAM available on the device
 * The file mem_info_vis_vram_total is used for this and returns the total
 * amount of visible VRAM in bytes
 */
static ssize_t amdgpu_mem_info_vis_vram_total_show(struct device *dev,
                struct device_attribute *attr, char *buf)
{
        struct drm_device *ddev = dev_get_drvdata(dev);
        struct amdgpu_device *adev = drm_to_adev(ddev);

        return sysfs_emit(buf, "%llu\n", adev->gmc.visible_vram_size);
}

/**
 * DOC: mem_info_vram_used
 *
 * The amdgpu driver provides a sysfs API for reporting current total VRAM
 * available on the device
 * The file mem_info_vram_used is used for this and returns the total
 * amount of currently used VRAM in bytes
 */
static ssize_t amdgpu_mem_info_vram_used_show(struct device *dev,
                                              struct device_attribute *attr,
                                              char *buf)
{
        struct drm_device *ddev = dev_get_drvdata(dev);
        struct amdgpu_device *adev = drm_to_adev(ddev);
        struct ttm_resource_manager *man;

        man = ttm_manager_type(&adev->mman.bdev, TTM_PL_VRAM);
        return sysfs_emit(buf, "%llu\n", amdgpu_vram_mgr_usage(man));
}

/**
 * DOC: mem_info_vis_vram_used
 *
 * The amdgpu driver provides a sysfs API for reporting current total of
 * used visible VRAM
 * The file mem_info_vis_vram_used is used for this and returns the total
 * amount of currently used visible VRAM in bytes
 */
static ssize_t amdgpu_mem_info_vis_vram_used_show(struct device *dev,
                                                  struct device_attribute *attr,
                                                  char *buf)
{
        struct drm_device *ddev = dev_get_drvdata(dev);
        struct amdgpu_device *adev = drm_to_adev(ddev);
        struct ttm_resource_manager *man;

        man = ttm_manager_type(&adev->mman.bdev, TTM_PL_VRAM);
        return sysfs_emit(buf, "%llu\n", amdgpu_vram_mgr_vis_usage(man));
}

/**
 * DOC: mem_info_vram_vendor
 *
 * The amdgpu driver provides a sysfs API for reporting the vendor of the
 * installed VRAM
 * The file mem_info_vram_vendor is used for this and returns the name of the
 * vendor.
 */
static ssize_t amdgpu_mem_info_vram_vendor(struct device *dev,
                                           struct device_attribute *attr,
                                           char *buf)
{
        struct drm_device *ddev = dev_get_drvdata(dev);
        struct amdgpu_device *adev = drm_to_adev(ddev);

        switch (adev->gmc.vram_vendor) {
        case SAMSUNG:
                return sysfs_emit(buf, "samsung\n");
        case INFINEON:
                return sysfs_emit(buf, "infineon\n");
        case ELPIDA:
                return sysfs_emit(buf, "elpida\n");
        case ETRON:
                return sysfs_emit(buf, "etron\n");
        case NANYA:
                return sysfs_emit(buf, "nanya\n");
        case HYNIX:
                return sysfs_emit(buf, "hynix\n");
        case MOSEL:
                return sysfs_emit(buf, "mosel\n");
        case WINBOND:
                return sysfs_emit(buf, "winbond\n");
        case ESMT:
                return sysfs_emit(buf, "esmt\n");
        case MICRON:
                return sysfs_emit(buf, "micron\n");
        default:
                return sysfs_emit(buf, "unknown\n");
        }
}

static DEVICE_ATTR(mem_info_vram_total, S_IRUGO,
                   amdgpu_mem_info_vram_total_show, NULL);
static DEVICE_ATTR(mem_info_vis_vram_total, S_IRUGO,
                   amdgpu_mem_info_vis_vram_total_show,NULL);
static DEVICE_ATTR(mem_info_vram_used, S_IRUGO,
                   amdgpu_mem_info_vram_used_show, NULL);
static DEVICE_ATTR(mem_info_vis_vram_used, S_IRUGO,
                   amdgpu_mem_info_vis_vram_used_show, NULL);
static DEVICE_ATTR(mem_info_vram_vendor, S_IRUGO,
                   amdgpu_mem_info_vram_vendor, NULL);

static struct attribute *amdgpu_vram_mgr_attributes[] = {
        &dev_attr_mem_info_vram_total.attr,
        &dev_attr_mem_info_vis_vram_total.attr,
        &dev_attr_mem_info_vram_used.attr,
        &dev_attr_mem_info_vis_vram_used.attr,
        &dev_attr_mem_info_vram_vendor.attr,
        NULL
};

const struct attribute_group amdgpu_vram_mgr_attr_group = {
        .attrs = amdgpu_vram_mgr_attributes
};

/**
 * amdgpu_vram_mgr_vis_size - Calculate visible node size
 *
 * @adev: amdgpu_device pointer
 * @node: MM node structure
 *
 * Calculate how many bytes of the MM node are inside visible VRAM
 */
static u64 amdgpu_vram_mgr_vis_size(struct amdgpu_device *adev,
                                    struct drm_mm_node *node)
{
        uint64_t start = node->start << PAGE_SHIFT;
        uint64_t end = (node->size + node->start) << PAGE_SHIFT;

        if (start >= adev->gmc.visible_vram_size)
                return 0;

        return (end > adev->gmc.visible_vram_size ?
                adev->gmc.visible_vram_size : end) - start;
}

/**
 * amdgpu_vram_mgr_bo_visible_size - CPU visible BO size
 *
 * @bo: &amdgpu_bo buffer object (must be in VRAM)
 *
 * Returns:
 * How much of the given &amdgpu_bo buffer object lies in CPU visible VRAM.
 */
u64 amdgpu_vram_mgr_bo_visible_size(struct amdgpu_bo *bo)
{
        struct amdgpu_device *adev = amdgpu_ttm_adev(bo->tbo.bdev);
        struct ttm_resource *res = bo->tbo.resource;
        unsigned pages = res->num_pages;
        struct drm_mm_node *mm;
        u64 usage;

        if (amdgpu_gmc_vram_full_visible(&adev->gmc))
                return amdgpu_bo_size(bo);

        if (res->start >= adev->gmc.visible_vram_size >> PAGE_SHIFT)
                return 0;

        mm = &container_of(res, struct ttm_range_mgr_node, base)->mm_nodes[0];
        for (usage = 0; pages; pages -= mm->size, mm++)
                usage += amdgpu_vram_mgr_vis_size(adev, mm);

        return usage;
}

/* Commit the reservation of VRAM pages */
static void amdgpu_vram_mgr_do_reserve(struct ttm_resource_manager *man)
{
        struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
        struct amdgpu_device *adev = to_amdgpu_device(mgr);
        struct drm_mm *mm = &mgr->mm;
        struct amdgpu_vram_reservation *rsv, *temp;
        uint64_t vis_usage;

        list_for_each_entry_safe(rsv, temp, &mgr->reservations_pending, node) {
                if (drm_mm_reserve_node(mm, &rsv->mm_node))
                        continue;

                dev_dbg(adev->dev, "Reservation 0x%llx - %lld, Succeeded\n",
                        rsv->mm_node.start, rsv->mm_node.size);

                vis_usage = amdgpu_vram_mgr_vis_size(adev, &rsv->mm_node);
                atomic64_add(vis_usage, &mgr->vis_usage);
                atomic64_add(rsv->mm_node.size << PAGE_SHIFT, &mgr->usage);
                list_move(&rsv->node, &mgr->reserved_pages);
        }
}

/**
 * amdgpu_vram_mgr_reserve_range - Reserve a range from VRAM
 *
 * @man: TTM memory type manager
 * @start: start address of the range in VRAM
 * @size: size of the range
 *
 * Reserve memory from start addess with the specified size in VRAM
 */
int amdgpu_vram_mgr_reserve_range(struct ttm_resource_manager *man,
                                  uint64_t start, uint64_t size)
{
        struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
        struct amdgpu_vram_reservation *rsv;

        rsv = kzalloc(sizeof(*rsv), GFP_KERNEL);
        if (!rsv)
                return -ENOMEM;

        INIT_LIST_HEAD(&rsv->node);
        rsv->mm_node.start = start >> PAGE_SHIFT;
        rsv->mm_node.size = size >> PAGE_SHIFT;

        spin_lock(&mgr->lock);
        list_add_tail(&mgr->reservations_pending, &rsv->node);
        amdgpu_vram_mgr_do_reserve(man);
        spin_unlock(&mgr->lock);

        return 0;
}

/**
 * amdgpu_vram_mgr_query_page_status - query the reservation status
 *
 * @man: TTM memory type manager
 * @start: start address of a page in VRAM
 *
 * Returns:
 *      -EBUSY: the page is still hold and in pending list
 *      0: the page has been reserved
 *      -ENOENT: the input page is not a reservation
 */
int amdgpu_vram_mgr_query_page_status(struct ttm_resource_manager *man,
                                      uint64_t start)
{
        struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
        struct amdgpu_vram_reservation *rsv;
        int ret;

        spin_lock(&mgr->lock);

        list_for_each_entry(rsv, &mgr->reservations_pending, node) {
                if ((rsv->mm_node.start <= start) &&
                    (start < (rsv->mm_node.start + rsv->mm_node.size))) {
                        ret = -EBUSY;
                        goto out;
                }
        }

        list_for_each_entry(rsv, &mgr->reserved_pages, node) {
                if ((rsv->mm_node.start <= start) &&
                    (start < (rsv->mm_node.start + rsv->mm_node.size))) {
                        ret = 0;
                        goto out;
                }
        }

        ret = -ENOENT;
out:
        spin_unlock(&mgr->lock);
        return ret;
}

/**
 * amdgpu_vram_mgr_virt_start - update virtual start address
 *
 * @mem: ttm_resource to update
 * @node: just allocated node
 *
 * Calculate a virtual BO start address to easily check if everything is CPU
 * accessible.
 */
static void amdgpu_vram_mgr_virt_start(struct ttm_resource *mem,
                                       struct drm_mm_node *node)
{
        unsigned long start;

        start = node->start + node->size;
        if (start > mem->num_pages)
                start -= mem->num_pages;
        else
                start = 0;
        mem->start = max(mem->start, start);
}

/**
 * amdgpu_vram_mgr_new - allocate new ranges
 *
 * @man: TTM memory type manager
 * @tbo: TTM BO we need this range for
 * @place: placement flags and restrictions
 * @res: the resulting mem object
 *
 * Allocate VRAM for the given BO.
 */
static int amdgpu_vram_mgr_new(struct ttm_resource_manager *man,
                               struct ttm_buffer_object *tbo,
                               const struct ttm_place *place,
                               struct ttm_resource **res)
{
        unsigned long lpfn, num_nodes, pages_per_node, pages_left, pages;
        struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
        struct amdgpu_device *adev = to_amdgpu_device(mgr);
        uint64_t vis_usage = 0, mem_bytes, max_bytes;
        struct ttm_range_mgr_node *node;
        struct drm_mm *mm = &mgr->mm;
        enum drm_mm_insert_mode mode;
        unsigned i;
        int r;

        lpfn = place->lpfn;
        if (!lpfn)
                lpfn = man->size;

        max_bytes = adev->gmc.mc_vram_size;
        if (tbo->type != ttm_bo_type_kernel)
                max_bytes -= AMDGPU_VM_RESERVED_VRAM;

        /* bail out quickly if there's likely not enough VRAM for this BO */
        mem_bytes = tbo->base.size;
        if (atomic64_add_return(mem_bytes, &mgr->usage) > max_bytes) {
                r = -ENOSPC;
                goto error_sub;
        }

        if (place->flags & TTM_PL_FLAG_CONTIGUOUS) {
                pages_per_node = ~0ul;
                num_nodes = 1;
        } else {
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
                pages_per_node = HPAGE_PMD_NR;
#else
                /* default to 2MB */
                pages_per_node = 2UL << (20UL - PAGE_SHIFT);
#endif
                pages_per_node = max_t(uint32_t, pages_per_node,
                                       tbo->page_alignment);
                num_nodes = DIV_ROUND_UP_ULL(PFN_UP(mem_bytes), pages_per_node);
        }

        node = kvmalloc(struct_size(node, mm_nodes, num_nodes),
                        GFP_KERNEL | __GFP_ZERO);
        if (!node) {
                r = -ENOMEM;
                goto error_sub;
        }

        ttm_resource_init(tbo, place, &node->base);

        mode = DRM_MM_INSERT_BEST;
        if (place->flags & TTM_PL_FLAG_TOPDOWN)
                mode = DRM_MM_INSERT_HIGH;

        pages_left = node->base.num_pages;

        /* Limit maximum size to 2GB due to SG table limitations */
        pages = min(pages_left, 2UL << (30 - PAGE_SHIFT));

        i = 0;
        spin_lock(&mgr->lock);
        while (pages_left) {
                uint32_t alignment = tbo->page_alignment;

                if (pages >= pages_per_node)
                        alignment = pages_per_node;

                r = drm_mm_insert_node_in_range(mm, &node->mm_nodes[i], pages,
                                                alignment, 0, place->fpfn,
                                                lpfn, mode);
                if (unlikely(r)) {
                        if (pages > pages_per_node) {
                                if (is_power_of_2(pages))
                                        pages = pages / 2;
                                else
                                        pages = rounddown_pow_of_two(pages);
                                continue;
                        }
                        goto error_free;
                }

                vis_usage += amdgpu_vram_mgr_vis_size(adev, &node->mm_nodes[i]);
                amdgpu_vram_mgr_virt_start(&node->base, &node->mm_nodes[i]);
                pages_left -= pages;
                ++i;

                if (pages > pages_left)
                        pages = pages_left;
        }
        spin_unlock(&mgr->lock);

        if (i == 1)
                node->base.placement |= TTM_PL_FLAG_CONTIGUOUS;

        if (adev->gmc.xgmi.connected_to_cpu)
                node->base.bus.caching = ttm_cached;
        else
                node->base.bus.caching = ttm_write_combined;

        atomic64_add(vis_usage, &mgr->vis_usage);
        *res = &node->base;
        return 0;

error_free:
        while (i--)
                drm_mm_remove_node(&node->mm_nodes[i]);
        spin_unlock(&mgr->lock);
        kvfree(node);

error_sub:
        atomic64_sub(mem_bytes, &mgr->usage);
        return r;
}

/**
 * amdgpu_vram_mgr_del - free ranges
 *
 * @man: TTM memory type manager
 * @res: TTM memory object
 *
 * Free the allocated VRAM again.
 */
static void amdgpu_vram_mgr_del(struct ttm_resource_manager *man,
                                struct ttm_resource *res)
{
        struct ttm_range_mgr_node *node = to_ttm_range_mgr_node(res);
        struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);
        struct amdgpu_device *adev = to_amdgpu_device(mgr);
        uint64_t usage = 0, vis_usage = 0;
        unsigned i, pages;

        spin_lock(&mgr->lock);
        for (i = 0, pages = res->num_pages; pages;
             pages -= node->mm_nodes[i].size, ++i) {
                struct drm_mm_node *mm = &node->mm_nodes[i];

                drm_mm_remove_node(mm);
                usage += mm->size << PAGE_SHIFT;
                vis_usage += amdgpu_vram_mgr_vis_size(adev, mm);
        }
        amdgpu_vram_mgr_do_reserve(man);
        spin_unlock(&mgr->lock);

        atomic64_sub(usage, &mgr->usage);
        atomic64_sub(vis_usage, &mgr->vis_usage);

        kvfree(node);
}

/**
 * amdgpu_vram_mgr_alloc_sgt - allocate and fill a sg table
 *
 * @adev: amdgpu device pointer
 * @res: TTM memory object
 * @offset: byte offset from the base of VRAM BO
 * @length: number of bytes to export in sg_table
 * @dev: the other device
 * @dir: dma direction
 * @sgt: resulting sg table
 *
 * Allocate and fill a sg table from a VRAM allocation.
 */
int amdgpu_vram_mgr_alloc_sgt(struct amdgpu_device *adev,
                              struct ttm_resource *res,
                              u64 offset, u64 length,
                              struct device *dev,
                              enum dma_data_direction dir,
                              struct sg_table **sgt)
{
        struct amdgpu_res_cursor cursor;
        struct scatterlist *sg;
        int num_entries = 0;
        int i, r;

        *sgt = kmalloc(sizeof(**sgt), GFP_KERNEL);
        if (!*sgt)
                return -ENOMEM;

        /* Determine the number of DRM_MM nodes to export */
        amdgpu_res_first(res, offset, length, &cursor);
        while (cursor.remaining) {
                num_entries++;
                amdgpu_res_next(&cursor, cursor.size);
        }

        r = sg_alloc_table(*sgt, num_entries, GFP_KERNEL);
        if (r)
                goto error_free;

        /* Initialize scatterlist nodes of sg_table */
        for_each_sgtable_sg((*sgt), sg, i)
                sg->length = 0;

        /*
         * Walk down DRM_MM nodes to populate scatterlist nodes
         * @note: Use iterator api to get first the DRM_MM node
         * and the number of bytes from it. Access the following
         * DRM_MM node(s) if more buffer needs to exported
         */
        amdgpu_res_first(res, offset, length, &cursor);
        for_each_sgtable_sg((*sgt), sg, i) {
                phys_addr_t phys = cursor.start + adev->gmc.aper_base;
                size_t size = cursor.size;
                dma_addr_t addr;

                addr = dma_map_resource(dev, phys, size, dir,
                                        DMA_ATTR_SKIP_CPU_SYNC);
                r = dma_mapping_error(dev, addr);
                if (r)
                        goto error_unmap;

                sg_set_page(sg, NULL, size, 0);
                sg_dma_address(sg) = addr;
                sg_dma_len(sg) = size;

                amdgpu_res_next(&cursor, cursor.size);
        }

        return 0;

error_unmap:
        for_each_sgtable_sg((*sgt), sg, i) {
                if (!sg->length)
                        continue;

                dma_unmap_resource(dev, sg->dma_address,
                                   sg->length, dir,
                                   DMA_ATTR_SKIP_CPU_SYNC);
        }
        sg_free_table(*sgt);

error_free:
        kfree(*sgt);
        return r;
}

/**
 * amdgpu_vram_mgr_free_sgt - allocate and fill a sg table
 *
 * @dev: device pointer
 * @dir: data direction of resource to unmap
 * @sgt: sg table to free
 *
 * Free a previously allocate sg table.
 */
void amdgpu_vram_mgr_free_sgt(struct device *dev,
                              enum dma_data_direction dir,
                              struct sg_table *sgt)
{
        struct scatterlist *sg;
        int i;

        for_each_sgtable_sg(sgt, sg, i)
                dma_unmap_resource(dev, sg->dma_address,
                                   sg->length, dir,
                                   DMA_ATTR_SKIP_CPU_SYNC);
        sg_free_table(sgt);
        kfree(sgt);
}

/**
 * amdgpu_vram_mgr_usage - how many bytes are used in this domain
 *
 * @man: TTM memory type manager
 *
 * Returns how many bytes are used in this domain.
 */
uint64_t amdgpu_vram_mgr_usage(struct ttm_resource_manager *man)
{
        struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);

        return atomic64_read(&mgr->usage);
}

/**
 * amdgpu_vram_mgr_vis_usage - how many bytes are used in the visible part
 *
 * @man: TTM memory type manager
 *
 * Returns how many bytes are used in the visible part of VRAM
 */
uint64_t amdgpu_vram_mgr_vis_usage(struct ttm_resource_manager *man)
{
        struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);

        return atomic64_read(&mgr->vis_usage);
}

/**
 * amdgpu_vram_mgr_debug - dump VRAM table
 *
 * @man: TTM memory type manager
 * @printer: DRM printer to use
 *
 * Dump the table content using printk.
 */
static void amdgpu_vram_mgr_debug(struct ttm_resource_manager *man,
                                  struct drm_printer *printer)
{
        struct amdgpu_vram_mgr *mgr = to_vram_mgr(man);

        spin_lock(&mgr->lock);
        drm_mm_print(&mgr->mm, printer);
        spin_unlock(&mgr->lock);

        drm_printf(printer, "man size:%llu pages, ram usage:%lluMB, vis usage:%lluMB\n",
                   man->size, amdgpu_vram_mgr_usage(man) >> 20,
                   amdgpu_vram_mgr_vis_usage(man) >> 20);
}

static const struct ttm_resource_manager_func amdgpu_vram_mgr_func = {
        .alloc  = amdgpu_vram_mgr_new,
        .free   = amdgpu_vram_mgr_del,
        .debug  = amdgpu_vram_mgr_debug
};

/**
 * amdgpu_vram_mgr_init - init VRAM manager and DRM MM
 *
 * @adev: amdgpu_device pointer
 *
 * Allocate and initialize the VRAM manager.
 */
int amdgpu_vram_mgr_init(struct amdgpu_device *adev)
{
        struct amdgpu_vram_mgr *mgr = &adev->mman.vram_mgr;
        struct ttm_resource_manager *man = &mgr->manager;

        ttm_resource_manager_init(man, adev->gmc.real_vram_size >> PAGE_SHIFT);

        man->func = &amdgpu_vram_mgr_func;

        drm_mm_init(&mgr->mm, 0, man->size);
        spin_lock_init(&mgr->lock);
        INIT_LIST_HEAD(&mgr->reservations_pending);
        INIT_LIST_HEAD(&mgr->reserved_pages);

        ttm_set_driver_manager(&adev->mman.bdev, TTM_PL_VRAM, &mgr->manager);
        ttm_resource_manager_set_used(man, true);
        return 0;
}

/**
 * amdgpu_vram_mgr_fini - free and destroy VRAM manager
 *
 * @adev: amdgpu_device pointer
 *
 * Destroy and free the VRAM manager, returns -EBUSY if ranges are still
 * allocated inside it.
 */
void amdgpu_vram_mgr_fini(struct amdgpu_device *adev)
{
        struct amdgpu_vram_mgr *mgr = &adev->mman.vram_mgr;
        struct ttm_resource_manager *man = &mgr->manager;
        int ret;
        struct amdgpu_vram_reservation *rsv, *temp;

        ttm_resource_manager_set_used(man, false);

        ret = ttm_resource_manager_evict_all(&adev->mman.bdev, man);
        if (ret)
                return;

        spin_lock(&mgr->lock);
        list_for_each_entry_safe(rsv, temp, &mgr->reservations_pending, node)
                kfree(rsv);

        list_for_each_entry_safe(rsv, temp, &mgr->reserved_pages, node) {
                drm_mm_remove_node(&rsv->mm_node);
                kfree(rsv);
        }
        drm_mm_takedown(&mgr->mm);
        spin_unlock(&mgr->lock);

        ttm_resource_manager_cleanup(man);
        ttm_set_driver_manager(&adev->mman.bdev, TTM_PL_VRAM, NULL);
}