text: /**************************************************************************
   *
   * Copyright (c) 2007-2009 VMware, Inc., Palo Alto, CA., USA
   * 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 above copyright notice and this permission notice (including the
   * next paragraph) 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 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.
   *
   **************************************************************************/
  /*
   * Authors: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
   */
  
  #include <drm/ttm/ttm_bo_driver.h>
  #include <drm/ttm/ttm_placement.h>
  #include <linux/io.h>
  #include <linux/highmem.h>
  #include <linux/wait.h>
  #include <linux/slab.h>
  #include <linux/vmalloc.h>
  #include <linux/module.h>
  
  void ttm_bo_free_old_node(struct ttm_buffer_object *bo)
  {
  	ttm_bo_mem_put(bo, &bo->mem);
  }
  
  int ttm_bo_move_ttm(struct ttm_buffer_object *bo,
  		    bool evict,
  		    bool no_wait_gpu, struct ttm_mem_reg *new_mem)
  {
  	struct ttm_tt *ttm = bo->ttm;
  	struct ttm_mem_reg *old_mem = &bo->mem;
  	int ret;
  
  	if (old_mem->mem_type != TTM_PL_SYSTEM) {
  		ttm_tt_unbind(ttm);
  		ttm_bo_free_old_node(bo);
  		ttm_flag_masked(&old_mem->placement, TTM_PL_FLAG_SYSTEM,
  				TTM_PL_MASK_MEM);
  		old_mem->mem_type = TTM_PL_SYSTEM;
  	}
  
  	ret = ttm_tt_set_placement_caching(ttm, new_mem->placement);
  	if (unlikely(ret != 0))
  		return ret;
  
  	if (new_mem->mem_type != TTM_PL_SYSTEM) {
  		ret = ttm_tt_bind(ttm, new_mem);
  		if (unlikely(ret != 0))
  			return ret;
  	}
  
  	*old_mem = *new_mem;
  	new_mem->mm_node = NULL;
  
  	return 0;
  }
  EXPORT_SYMBOL(ttm_bo_move_ttm);
  
  int ttm_mem_io_lock(struct ttm_mem_type_manager *man, bool interruptible)
  {
  	if (likely(man->io_reserve_fastpath))
  		return 0;
  
  	if (interruptible)
  		return mutex_lock_interruptible(&man->io_reserve_mutex);
  
  	mutex_lock(&man->io_reserve_mutex);
  	return 0;
  }
  EXPORT_SYMBOL(ttm_mem_io_lock);
  
  void ttm_mem_io_unlock(struct ttm_mem_type_manager *man)
  {
  	if (likely(man->io_reserve_fastpath))
  		return;
  
  	mutex_unlock(&man->io_reserve_mutex);
  }
  EXPORT_SYMBOL(ttm_mem_io_unlock);
  
  static int ttm_mem_io_evict(struct ttm_mem_type_manager *man)
  {
  	struct ttm_buffer_object *bo;
  
  	if (!man->use_io_reserve_lru || list_empty(&man->io_reserve_lru))
  		return -EAGAIN;
  
  	bo = list_first_entry(&man->io_reserve_lru,
  			      struct ttm_buffer_object,
  			      io_reserve_lru);
  	list_del_init(&bo->io_reserve_lru);
  	ttm_bo_unmap_virtual_locked(bo);
  
  	return 0;
  }
  
  
  int ttm_mem_io_reserve(struct ttm_bo_device *bdev,
  		       struct ttm_mem_reg *mem)
  {
  	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
  	int ret = 0;
  
  	if (!bdev->driver->io_mem_reserve)
  		return 0;
  	if (likely(man->io_reserve_fastpath))
  		return bdev->driver->io_mem_reserve(bdev, mem);
  
  	if (bdev->driver->io_mem_reserve &&
  	    mem->bus.io_reserved_count++ == 0) {
  retry:
  		ret = bdev->driver->io_mem_reserve(bdev, mem);
  		if (ret == -EAGAIN) {
  			ret = ttm_mem_io_evict(man);
  			if (ret == 0)
  				goto retry;
  		}
  	}
  	return ret;
  }
  EXPORT_SYMBOL(ttm_mem_io_reserve);
  
  void ttm_mem_io_free(struct ttm_bo_device *bdev,
  		     struct ttm_mem_reg *mem)
  {
  	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
  
  	if (likely(man->io_reserve_fastpath))
  		return;
  
  	if (bdev->driver->io_mem_reserve &&
  	    --mem->bus.io_reserved_count == 0 &&
  	    bdev->driver->io_mem_free)
  		bdev->driver->io_mem_free(bdev, mem);
  
  }
  EXPORT_SYMBOL(ttm_mem_io_free);
  
  int ttm_mem_io_reserve_vm(struct ttm_buffer_object *bo)
  {
  	struct ttm_mem_reg *mem = &bo->mem;
  	int ret;
  
  	if (!mem->bus.io_reserved_vm) {
  		struct ttm_mem_type_manager *man =
  			&bo->bdev->man[mem->mem_type];
  
  		ret = ttm_mem_io_reserve(bo->bdev, mem);
  		if (unlikely(ret != 0))
  			return ret;
  		mem->bus.io_reserved_vm = true;
  		if (man->use_io_reserve_lru)
  			list_add_tail(&bo->io_reserve_lru,
  				      &man->io_reserve_lru);
  	}
  	return 0;
  }
  
  void ttm_mem_io_free_vm(struct ttm_buffer_object *bo)
  {
  	struct ttm_mem_reg *mem = &bo->mem;
  
  	if (mem->bus.io_reserved_vm) {
  		mem->bus.io_reserved_vm = false;
  		list_del_init(&bo->io_reserve_lru);
  		ttm_mem_io_free(bo->bdev, mem);
  	}
  }
  
  int ttm_mem_reg_ioremap(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem,
  			void **virtual)
  {
  	struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
  	int ret;
  	void *addr;
  
  	*virtual = NULL;
  	(void) ttm_mem_io_lock(man, false);
  	ret = ttm_mem_io_reserve(bdev, mem);
  	ttm_mem_io_unlock(man);
  	if (ret || !mem->bus.is_iomem)
  		return ret;
  
  	if (mem->bus.addr) {
  		addr = mem->bus.addr;
  	} else {
  		if (mem->placement & TTM_PL_FLAG_WC)
  			addr = ioremap_wc(mem->bus.base + mem->bus.offset, mem->bus.size);
  		else
  			addr = ioremap_nocache(mem->bus.base + mem->bus.offset, mem->bus.size);
  		if (!addr) {
  			(void) ttm_mem_io_lock(man, false);
  			ttm_mem_io_free(bdev, mem);
  			ttm_mem_io_unlock(man);
  			return -ENOMEM;
  		}
  	}
  	*virtual = addr;
  	return 0;
  }
  
  void ttm_mem_reg_iounmap(struct ttm_bo_device *bdev, struct ttm_mem_reg *mem,
  			 void *virtual)
  {
  	struct ttm_mem_type_manager *man;
  
  	man = &bdev->man[mem->mem_type];
  
  	if (virtual && mem->bus.addr == NULL)
  		iounmap(virtual);
  	(void) ttm_mem_io_lock(man, false);
  	ttm_mem_io_free(bdev, mem);
  	ttm_mem_io_unlock(man);
  }
  
  static int ttm_copy_io_page(void *dst, void *src, unsigned long page)
  {
  	uint32_t *dstP =
  	    (uint32_t *) ((unsigned long)dst + (page << PAGE_SHIFT));
  	uint32_t *srcP =
  	    (uint32_t *) ((unsigned long)src + (page << PAGE_SHIFT));
  
  	int i;
  	for (i = 0; i < PAGE_SIZE / sizeof(uint32_t); ++i)
  		iowrite32(ioread32(srcP++), dstP++);
  	return 0;
  }
  
  static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
  				unsigned long page,
  				pgprot_t prot)
  {
  	struct page *d = ttm->pages[page];
  	void *dst;
  
  	if (!d)
  		return -ENOMEM;
  
  	src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
  
  #ifdef CONFIG_X86
  	dst = kmap_atomic_prot(d, prot);
  #else
  	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
  		dst = vmap(&d, 1, 0, prot);
  	else
  		dst = kmap(d);
  #endif
  	if (!dst)
  		return -ENOMEM;
  
  	memcpy_fromio(dst, src, PAGE_SIZE);
  
  #ifdef CONFIG_X86
  	kunmap_atomic(dst);
  #else
  	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
  		vunmap(dst);
  	else
  		kunmap(d);
  #endif
  
  	return 0;
  }
  
  static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
  				unsigned long page,
  				pgprot_t prot)
  {
  	struct page *s = ttm->pages[page];
  	void *src;
  
  	if (!s)
  		return -ENOMEM;
  
  	dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
  #ifdef CONFIG_X86
  	src = kmap_atomic_prot(s, prot);
  #else
  	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
  		src = vmap(&s, 1, 0, prot);
  	else
  		src = kmap(s);
  #endif
  	if (!src)
  		return -ENOMEM;
  
  	memcpy_toio(dst, src, PAGE_SIZE);
  
  #ifdef CONFIG_X86
  	kunmap_atomic(src);
  #else
  	if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL))
  		vunmap(src);
  	else
  		kunmap(s);
  #endif
  
  	return 0;
  }
  
  int ttm_bo_move_memcpy(struct ttm_buffer_object *bo,
  		       bool evict, bool no_wait_gpu,
  		       struct ttm_mem_reg *new_mem)
  {
  	struct ttm_bo_device *bdev = bo->bdev;
  	struct ttm_mem_type_manager *man = &bdev->man[new_mem->mem_type];
  	struct ttm_tt *ttm = bo->ttm;
  	struct ttm_mem_reg *old_mem = &bo->mem;
  	struct ttm_mem_reg old_copy = *old_mem;
  	void *old_iomap;
  	void *new_iomap;
  	int ret;
  	unsigned long i;
  	unsigned long page;
  	unsigned long add = 0;
  	int dir;
  
  	ret = ttm_mem_reg_ioremap(bdev, old_mem, &old_iomap);
  	if (ret)
  		return ret;
  	ret = ttm_mem_reg_ioremap(bdev, new_mem, &new_iomap);
  	if (ret)
  		goto out;
  
  	/*
  	 * Single TTM move. NOP.
  	 */
  	if (old_iomap == NULL && new_iomap == NULL)
  		goto out2;
  
  	/*
  	 * Move nonexistent data. NOP.
  	 */
  	if (old_iomap == NULL && ttm == NULL)
  		goto out2;
  
  	/*
  	 * TTM might be null for moves within the same region.
  	 */
  	if (ttm && ttm->state == tt_unpopulated) {
  		ret = ttm->bdev->driver->ttm_tt_populate(ttm);
  		if (ret)
  			goto out1;
  	}
  
  	add = 0;
  	dir = 1;
  
  	if ((old_mem->mem_type == new_mem->mem_type) &&
  	    (new_mem->start < old_mem->start + old_mem->size)) {
  		dir = -1;
  		add = new_mem->num_pages - 1;
  	}
  
  	for (i = 0; i < new_mem->num_pages; ++i) {
  		page = i * dir + add;
  		if (old_iomap == NULL) {
  			pgprot_t prot = ttm_io_prot(old_mem->placement,
  						    PAGE_KERNEL);
  			ret = ttm_copy_ttm_io_page(ttm, new_iomap, page,
  						   prot);
  		} else if (new_iomap == NULL) {
  			pgprot_t prot = ttm_io_prot(new_mem->placement,
  						    PAGE_KERNEL);
  			ret = ttm_copy_io_ttm_page(ttm, old_iomap, page,
  						   prot);
  		} else
  			ret = ttm_copy_io_page(new_iomap, old_iomap, page);
  		if (ret)
  			goto out1;
  	}
  	mb();
  out2:
  	old_copy = *old_mem;
  	*old_mem = *new_mem;
  	new_mem->mm_node = NULL;
  
  	if ((man->flags & TTM_MEMTYPE_FLAG_FIXED) && (ttm != NULL)) {
  		ttm_tt_unbind(ttm);
  		ttm_tt_destroy(ttm);
  		bo->ttm = NULL;
  	}
  
  out1:
  	ttm_mem_reg_iounmap(bdev, old_mem, new_iomap);
  out:
  	ttm_mem_reg_iounmap(bdev, &old_copy, old_iomap);
  
  	/*
  	 * On error, keep the mm node!
  	 */
  	if (!ret)
  		ttm_bo_mem_put(bo, &old_copy);
  	return ret;
  }
  EXPORT_SYMBOL(ttm_bo_move_memcpy);
  
  static void ttm_transfered_destroy(struct ttm_buffer_object *bo)
  {
  	kfree(bo);
  }
  
  /**
   * ttm_buffer_object_transfer
   *
   * @bo: A pointer to a struct ttm_buffer_object.
   * @new_obj: A pointer to a pointer to a newly created ttm_buffer_object,
   * holding the data of @bo with the old placement.
   *
   * This is a utility function that may be called after an accelerated move
   * has been scheduled. A new buffer object is created as a placeholder for
   * the old data while it's being copied. When that buffer object is idle,
   * it can be destroyed, releasing the space of the old placement.
   * Returns:
   * !0: Failure.
   */
  
  static int ttm_buffer_object_transfer(struct ttm_buffer_object *bo,
  				      struct ttm_buffer_object **new_obj)
  {
  	struct ttm_buffer_object *fbo;
  	struct ttm_bo_device *bdev = bo->bdev;
  	struct ttm_bo_driver *driver = bdev->driver;
  
  	fbo = kmalloc(sizeof(*fbo), GFP_KERNEL);
  	if (!fbo)
  		return -ENOMEM;
  
  	*fbo = *bo;
  
  	/**
  	 * Fix up members that we shouldn't copy directly:
  	 * TODO: Explicit member copy would probably be better here.
  	 */
  
  	init_waitqueue_head(&fbo->event_queue);
  	INIT_LIST_HEAD(&fbo->ddestroy);
  	INIT_LIST_HEAD(&fbo->lru);
  	INIT_LIST_HEAD(&fbo->swap);
  	INIT_LIST_HEAD(&fbo->io_reserve_lru);
  	fbo->vm_node = NULL;
  	atomic_set(&fbo->cpu_writers, 0);
  
  	spin_lock(&bdev->fence_lock);
  	if (bo->sync_obj)
  		fbo->sync_obj = driver->sync_obj_ref(bo->sync_obj);
  	else
  		fbo->sync_obj = NULL;
  	spin_unlock(&bdev->fence_lock);
  	kref_init(&fbo->list_kref);
  	kref_init(&fbo->kref);
  	fbo->destroy = &ttm_transfered_destroy;
  	fbo->acc_size = 0;
  
  	*new_obj = fbo;
  	return 0;
  }
  
  pgprot_t ttm_io_prot(uint32_t caching_flags, pgprot_t tmp)
  {
  #if defined(__i386__) || defined(__x86_64__)
  	if (caching_flags & TTM_PL_FLAG_WC)
  		tmp = pgprot_writecombine(tmp);
  	else if (boot_cpu_data.x86 > 3)
  		tmp = pgprot_noncached(tmp);
  
  #elif defined(__powerpc__)
  	if (!(caching_flags & TTM_PL_FLAG_CACHED)) {
  		pgprot_val(tmp) |= _PAGE_NO_CACHE;
  		if (caching_flags & TTM_PL_FLAG_UNCACHED)
  			pgprot_val(tmp) |= _PAGE_GUARDED;
  	}
  #endif
  #if defined(__ia64__)
  	if (caching_flags & TTM_PL_FLAG_WC)
  		tmp = pgprot_writecombine(tmp);
  	else
  		tmp = pgprot_noncached(tmp);
  #endif
  #if defined(__sparc__) || defined(__mips__)
  	if (!(caching_flags & TTM_PL_FLAG_CACHED))
  		tmp = pgprot_noncached(tmp);
  #endif
  	return tmp;
  }
  EXPORT_SYMBOL(ttm_io_prot);
  
  static int ttm_bo_ioremap(struct ttm_buffer_object *bo,
  			  unsigned long offset,
  			  unsigned long size,
  			  struct ttm_bo_kmap_obj *map)
  {
  	struct ttm_mem_reg *mem = &bo->mem;
  
  	if (bo->mem.bus.addr) {
  		map->bo_kmap_type = ttm_bo_map_premapped;
  		map->virtual = (void *)(((u8 *)bo->mem.bus.addr) + offset);
  	} else {
  		map->bo_kmap_type = ttm_bo_map_iomap;
  		if (mem->placement & TTM_PL_FLAG_WC)
  			map->virtual = ioremap_wc(bo->mem.bus.base + bo->mem.bus.offset + offset,
  						  size);
  		else
  			map->virtual = ioremap_nocache(bo->mem.bus.base + bo->mem.bus.offset + offset,
  						       size);
  	}
  	return (!map->virtual) ? -ENOMEM : 0;
  }
  
  static int ttm_bo_kmap_ttm(struct ttm_buffer_object *bo,
  			   unsigned long start_page,
  			   unsigned long num_pages,
  			   struct ttm_bo_kmap_obj *map)
  {
  	struct ttm_mem_reg *mem = &bo->mem; pgprot_t prot;
  	struct ttm_tt *ttm = bo->ttm;
  	int ret;
  
  	BUG_ON(!ttm);
  
  	if (ttm->state == tt_unpopulated) {
  		ret = ttm->bdev->driver->ttm_tt_populate(ttm);
  		if (ret)
  			return ret;
  	}
  
  	if (num_pages == 1 && (mem->placement & TTM_PL_FLAG_CACHED)) {
  		/*
  		 * We're mapping a single page, and the desired
  		 * page protection is consistent with the bo.
  		 */
  
  		map->bo_kmap_type = ttm_bo_map_kmap;
  		map->page = ttm->pages[start_page];
  		map->virtual = kmap(map->page);
  	} else {
  		/*
  		 * We need to use vmap to get the desired page protection
  		 * or to make the buffer object look contiguous.
  		 */
  		prot = (mem->placement & TTM_PL_FLAG_CACHED) ?
  			PAGE_KERNEL :
  			ttm_io_prot(mem->placement, PAGE_KERNEL);
  		map->bo_kmap_type = ttm_bo_map_vmap;
  		map->virtual = vmap(ttm->pages + start_page, num_pages,
  				    0, prot);
  	}
  	return (!map->virtual) ? -ENOMEM : 0;
  }
  
  int ttm_bo_kmap(struct ttm_buffer_object *bo,
  		unsigned long start_page, unsigned long num_pages,
  		struct ttm_bo_kmap_obj *map)
  {
  	struct ttm_mem_type_manager *man =
  		&bo->bdev->man[bo->mem.mem_type];
  	unsigned long offset, size;
  	int ret;
  
  	BUG_ON(!list_empty(&bo->swap));
  	map->virtual = NULL;
  	map->bo = bo;
  	if (num_pages > bo->num_pages)
  		return -EINVAL;
  	if (start_page > bo->num_pages)
  		return -EINVAL;
  #if 0
  	if (num_pages > 1 && !DRM_SUSER(DRM_CURPROC))
  		return -EPERM;
  #endif
  	(void) ttm_mem_io_lock(man, false);
  	ret = ttm_mem_io_reserve(bo->bdev, &bo->mem);
  	ttm_mem_io_unlock(man);
  	if (ret)
  		return ret;
  	if (!bo->mem.bus.is_iomem) {
  		return ttm_bo_kmap_ttm(bo, start_page, num_pages, map);
  	} else {
  		offset = start_page << PAGE_SHIFT;
  		size = num_pages << PAGE_SHIFT;
  		return ttm_bo_ioremap(bo, offset, size, map);
  	}
  }
  EXPORT_SYMBOL(ttm_bo_kmap);
  
  void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
  {
  	struct ttm_buffer_object *bo = map->bo;
  	struct ttm_mem_type_manager *man =
  		&bo->bdev->man[bo->mem.mem_type];
  
  	if (!map->virtual)
  		return;
  	switch (map->bo_kmap_type) {
  	case ttm_bo_map_iomap:
  		iounmap(map->virtual);
  		break;
  	case ttm_bo_map_vmap:
  		vunmap(map->virtual);
  		break;
  	case ttm_bo_map_kmap:
  		kunmap(map->page);
  		break;
  	case ttm_bo_map_premapped:
  		break;
  	default:
  		BUG();
  	}
  	(void) ttm_mem_io_lock(man, false);
  	ttm_mem_io_free(map->bo->bdev, &map->bo->mem);
  	ttm_mem_io_unlock(man);
  	map->virtual = NULL;
  	map->page = NULL;
  }
  EXPORT_SYMBOL(ttm_bo_kunmap);
  
  int ttm_bo_move_accel_cleanup(struct ttm_buffer_object *bo,
  			      void *sync_obj,
  			      bool evict,
  			      bool no_wait_gpu,
  			      struct ttm_mem_reg *new_mem)
  {
  	struct ttm_bo_device *bdev = bo->bdev;
  	struct ttm_bo_driver *driver = bdev->driver;
  	struct ttm_mem_type_manager *man = &bdev->man[new_mem->mem_type];
  	struct ttm_mem_reg *old_mem = &bo->mem;
  	int ret;
  	struct ttm_buffer_object *ghost_obj;
  	void *tmp_obj = NULL;
  
  	spin_lock(&bdev->fence_lock);
  	if (bo->sync_obj) {
  		tmp_obj = bo->sync_obj;
  		bo->sync_obj = NULL;
  	}
  	bo->sync_obj = driver->sync_obj_ref(sync_obj);
  	if (evict) {
  		ret = ttm_bo_wait(bo, false, false, false);
  		spin_unlock(&bdev->fence_lock);
  		if (tmp_obj)
  			driver->sync_obj_unref(&tmp_obj);
  		if (ret)
  			return ret;
  
  		if ((man->flags & TTM_MEMTYPE_FLAG_FIXED) &&
  		    (bo->ttm != NULL)) {
  			ttm_tt_unbind(bo->ttm);
  			ttm_tt_destroy(bo->ttm);
  			bo->ttm = NULL;
  		}
  		ttm_bo_free_old_node(bo);
  	} else {
  		/**
  		 * This should help pipeline ordinary buffer moves.
  		 *
  		 * Hang old buffer memory on a new buffer object,
  		 * and leave it to be released when the GPU
  		 * operation has completed.
  		 */
  
  		set_bit(TTM_BO_PRIV_FLAG_MOVING, &bo->priv_flags);
  		spin_unlock(&bdev->fence_lock);
  		if (tmp_obj)
  			driver->sync_obj_unref(&tmp_obj);
  
  		ret = ttm_buffer_object_transfer(bo, &ghost_obj);
  		if (ret)
  			return ret;
  
  		/**
  		 * If we're not moving to fixed memory, the TTM object
  		 * needs to stay alive. Otherwhise hang it on the ghost
  		 * bo to be unbound and destroyed.
  		 */
  
  		if (!(man->flags & TTM_MEMTYPE_FLAG_FIXED))
  			ghost_obj->ttm = NULL;
  		else
  			bo->ttm = NULL;
  
  		ttm_bo_unreserve(ghost_obj);
  		ttm_bo_unref(&ghost_obj);
  	}
  
  	*old_mem = *new_mem;
  	new_mem->mm_node = NULL;
  
  	return 0;
  }
  EXPORT_SYMBOL(ttm_bo_move_accel_cleanup);
  