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/*

 * GART

 * The GART (Graphics Aperture Remapping Table) is an aperture

 * in the GPU's address space.  System pages can be mapped into

 * the aperture and look like contiguous pages from the GPU's

 * perspective.  A page table maps the pages in the aperture

 * to the actual backing pages in system memory.

 *

 * Radeon GPUs support both an internal GART, as described above,

 * and AGP.  AGP works similarly, but the GART table is configured

 * and maintained by the northbridge rather than the driver.

 * Radeon hw has a separate AGP aperture that is programmed to

 * point to the AGP aperture provided by the northbridge and the

 * requests are passed through to the northbridge aperture.

 * Both AGP and internal GART can be used at the same time, however

 * that is not currently supported by the driver.

 *

 * This file handles the common internal GART management.

 */

 */

/**

 * radeon_gart_table_ram_alloc - allocate system ram for gart page table

 *

 * @rdev: radeon_device pointer

 *

 * Allocate system memory for GART page table

 * (r1xx-r3xx, non-pcie r4xx, rs400).  These asics require the

 * gart table to be in system memory.

 * Returns 0 for success, -ENOMEM for failure.

/**

 * radeon_gart_table_ram_free - free system ram for gart page table

 *

 * @rdev: radeon_device pointer

 *

 * Free system memory for GART page table

 * (r1xx-r3xx, non-pcie r4xx, rs400).  These asics require the

 * gart table to be in system memory.

}

/**

 * radeon_gart_table_vram_alloc - allocate vram for gart page table

 *

 * @rdev: radeon_device pointer

 *

 * Allocate video memory for GART page table

 * (pcie r4xx, r5xx+).  These asics require the

 * gart table to be in video memory.

    }

	return 0;

}

/**

 * radeon_gart_table_vram_pin - pin gart page table in vram

 *

 * @rdev: radeon_device pointer

 *

 * Pin the GART page table in vram so it will not be moved

		radeon_bo_unpin(rdev->gart.robj);

	radeon_bo_unreserve(rdev->gart.robj);

	rdev->gart.table_addr = gpu_addr;

    return r;

}

/**

 * radeon_gart_table_vram_unpin - unpin gart page table in vram

		return;

	if (likely(r == 0)) {

		radeon_bo_kunmap(rdev->gart.robj);

		radeon_bo_unpin(rdev->gart.robj);

		radeon_bo_unreserve(rdev->gart.robj);

		rdev->gart.ptr = NULL;

	}

}

/**

 * radeon_gart_table_vram_free - free gart page table vram

 * @rdev: radeon_device pointer

 *

 * Free the video memory used for the GART page table

 * (pcie r4xx, r5xx+).  These asics require the gart table to

 * be in video memory.

		return;

	}

	radeon_gart_table_vram_unpin(rdev);

	radeon_bo_unref(&rdev->gart.robj);

}

/*

 * Common gart functions.

 */

/**

				if (rdev->gart.ptr) {

				}

/**

 * radeon_gart_bind - bind pages into the gart page table

 *

 * @rdev: radeon_device pointer

 * @offset: offset into the GPU's gart aperture

 * @pages: number of pages to bind

 * @pagelist: pages to bind

 * @dma_addr: DMA addresses of pages

 *

 * Binds the requested pages to the gart page table

 * (all asics).

 * Returns 0 for success, -EINVAL for failure.

    for (i = 0; i < pages; i++, p++) {

			page_base += RADEON_GPU_PAGE_SIZE;

    radeon_gart_tlb_flush(rdev);

    return 0;

}

/**

 * radeon_gart_restore - bind all pages in the gart page table

 *

 * @rdev: radeon_device pointer

void radeon_gart_restore(struct radeon_device *rdev)

{

	int i, j, t;

/**

 * radeon_gart_init - init the driver info for managing the gart

 *

 * @rdev: radeon_device pointer

 *

 * Allocate the dummy page and init the gart driver info (all asics).

 * Returns 0 for success, error for failure.

/**

 * radeon_gart_fini - tear down the driver info for managing the gart

 *

 * @rdev: radeon_device pointer

 *

 * Tear down the gart driver info and free the dummy page (all asics).

}

/*

 * GPUVM

 * GPUVM is similar to the legacy gart on older asics, however

 * rather than there being a single global gart table

 * for the entire GPU, there are multiple VM page tables active

 * at any given time.  The VM page tables can contain a mix

 * vram pages and system memory pages and system memory pages

 * can be mapped as snooped (cached system pages) or unsnooped

 * (uncached system pages).

 * Each VM has an ID associated with it and there is a page table

 * associated with each VMID.  When execting a command buffer,

 * the kernel tells the the ring what VMID to use for that command

 * buffer.  VMIDs are allocated dynamically as commands are submitted.

 * The userspace drivers maintain their own address space and the kernel

 * sets up their pages tables accordingly when they submit their

 * command buffers and a VMID is assigned.

 * Cayman/Trinity support up to 8 active VMs at any given time;

 * SI supports 16.

 */

/*

 * vm helpers

 *

 * TODO bind a default page at vm initialization for default address

 */

/**

 * radeon_vm_num_pde - return the number of page directory entries

 *

 * @rdev: radeon_device pointer

 *

 * Calculate the number of page directory entries (cayman+).

 */

static unsigned radeon_vm_num_pdes(struct radeon_device *rdev)

{

	return rdev->vm_manager.max_pfn >> RADEON_VM_BLOCK_SIZE;

}

/**

 * radeon_vm_directory_size - returns the size of the page directory in bytes

 *

 * @rdev: radeon_device pointer

 *

 * Calculate the size of the page directory in bytes (cayman+).

 */

static unsigned radeon_vm_directory_size(struct radeon_device *rdev)

{

	return RADEON_GPU_PAGE_ALIGN(radeon_vm_num_pdes(rdev) * 8);

}

/**

 * radeon_vm_manager_init - init the vm manager

 *

 * @rdev: radeon_device pointer

 *

 * Init the vm manager (cayman+).

 * Returns 0 for success, error for failure.

 */

int radeon_vm_manager_init(struct radeon_device *rdev)

{

	struct radeon_vm *vm;

	struct radeon_bo_va *bo_va;

	int r;

	unsigned size;

	if (!rdev->vm_manager.enabled) {

		/* allocate enough for 2 full VM pts */

		size = radeon_vm_directory_size(rdev);

		size += rdev->vm_manager.max_pfn * 8;

		size *= 2;

		r = radeon_sa_bo_manager_init(rdev, &rdev->vm_manager.sa_manager,

					      RADEON_GPU_PAGE_ALIGN(size),

					      RADEON_GEM_DOMAIN_VRAM);

		if (r) {

			dev_err(rdev->dev, "failed to allocate vm bo (%dKB)\n",

				(rdev->vm_manager.max_pfn * 8) >> 10);

			return r;

		}

		r = radeon_asic_vm_init(rdev);

		if (r)

			return r;

		rdev->vm_manager.enabled = true;

		r = radeon_sa_bo_manager_start(rdev, &rdev->vm_manager.sa_manager);

		if (r)

			return r;

	}

	/* restore page table */

	list_for_each_entry(vm, &rdev->vm_manager.lru_vm, list) {

		if (vm->page_directory == NULL)

			continue;

		list_for_each_entry(bo_va, &vm->va, vm_list) {

			bo_va->valid = false;

		}

	}

	return 0;

}

/**

 * radeon_vm_free_pt - free the page table for a specific vm

 *

 * @rdev: radeon_device pointer

 * @vm: vm to unbind

 *

 * Free the page table of a specific vm (cayman+).

 *

 * Global and local mutex must be lock!

 */

static void radeon_vm_free_pt(struct radeon_device *rdev,

				    struct radeon_vm *vm)

{

	struct radeon_bo_va *bo_va;

	int i;

	if (!vm->page_directory)

		return;

	list_del_init(&vm->list);

	radeon_sa_bo_free(rdev, &vm->page_directory, vm->fence);

	list_for_each_entry(bo_va, &vm->va, vm_list) {

		bo_va->valid = false;

	}

	if (vm->page_tables == NULL)

		return;

	for (i = 0; i < radeon_vm_num_pdes(rdev); i++)

		radeon_sa_bo_free(rdev, &vm->page_tables[i], vm->fence);

	kfree(vm->page_tables);

}

/**

 * radeon_vm_manager_fini - tear down the vm manager

 *

 * @rdev: radeon_device pointer

 *

 * Tear down the VM manager (cayman+).

 */

void radeon_vm_manager_fini(struct radeon_device *rdev)

{

	struct radeon_vm *vm, *tmp;

	int i;

	if (!rdev->vm_manager.enabled)

		return;

	mutex_lock(&rdev->vm_manager.lock);

	/* free all allocated page tables */

	list_for_each_entry_safe(vm, tmp, &rdev->vm_manager.lru_vm, list) {

		mutex_lock(&vm->mutex);

		radeon_vm_free_pt(rdev, vm);

		mutex_unlock(&vm->mutex);

	}

	for (i = 0; i < RADEON_NUM_VM; ++i) {

		radeon_fence_unref(&rdev->vm_manager.active[i]);

	}

	radeon_asic_vm_fini(rdev);

	mutex_unlock(&rdev->vm_manager.lock);

	radeon_sa_bo_manager_suspend(rdev, &rdev->vm_manager.sa_manager);

	radeon_sa_bo_manager_fini(rdev, &rdev->vm_manager.sa_manager);

	rdev->vm_manager.enabled = false;

}

/**

 * radeon_vm_evict - evict page table to make room for new one

 *

 * @rdev: radeon_device pointer

 * @vm: VM we want to allocate something for

 *

 * Evict a VM from the lru, making sure that it isn't @vm. (cayman+).

 * Returns 0 for success, -ENOMEM for failure.

 *

 * Global and local mutex must be locked!

 */

static int radeon_vm_evict(struct radeon_device *rdev, struct radeon_vm *vm)

{

	struct radeon_vm *vm_evict;

	if (list_empty(&rdev->vm_manager.lru_vm))

		return -ENOMEM;

	vm_evict = list_first_entry(&rdev->vm_manager.lru_vm,

				    struct radeon_vm, list);

	if (vm_evict == vm)

		return -ENOMEM;

	mutex_lock(&vm_evict->mutex);

	radeon_vm_free_pt(rdev, vm_evict);

	mutex_unlock(&vm_evict->mutex);

	return 0;

}

/**

 * radeon_vm_alloc_pt - allocates a page table for a VM

 *

 * @rdev: radeon_device pointer

 * @vm: vm to bind

 *

 * Allocate a page table for the requested vm (cayman+).

 * Returns 0 for success, error for failure.

 *

 * Global and local mutex must be locked!

 */

int radeon_vm_alloc_pt(struct radeon_device *rdev, struct radeon_vm *vm)

{

	unsigned pd_size, pts_size;

	u64 *pd_addr;

	int r;

	if (vm == NULL) {

		return -EINVAL;

	}

	if (vm->page_directory != NULL) {

		return 0;

	}

retry:

	pd_size = RADEON_GPU_PAGE_ALIGN(radeon_vm_directory_size(rdev));

	r = radeon_sa_bo_new(rdev, &rdev->vm_manager.sa_manager,

			     &vm->page_directory, pd_size,

			     RADEON_GPU_PAGE_SIZE, false);

	if (r == -ENOMEM) {

		r = radeon_vm_evict(rdev, vm);

		if (r)

			return r;

		goto retry;

	} else if (r) {

		return r;

	}

	vm->pd_gpu_addr = radeon_sa_bo_gpu_addr(vm->page_directory);

	/* Initially clear the page directory */

	pd_addr = radeon_sa_bo_cpu_addr(vm->page_directory);

	memset(pd_addr, 0, pd_size);

	pts_size = radeon_vm_num_pdes(rdev) * sizeof(struct radeon_sa_bo *);

	vm->page_tables = kzalloc(pts_size, GFP_KERNEL);

	if (vm->page_tables == NULL) {

		DRM_ERROR("Cannot allocate memory for page table array\n");

		radeon_sa_bo_free(rdev, &vm->page_directory, vm->fence);

		return -ENOMEM;

	}

	return 0;

}

/**

 * radeon_vm_add_to_lru - add VMs page table to LRU list

 *

 * @rdev: radeon_device pointer

 * @vm: vm to add to LRU

 *

 * Add the allocated page table to the LRU list (cayman+).

 *

 * Global mutex must be locked!

 */

void radeon_vm_add_to_lru(struct radeon_device *rdev, struct radeon_vm *vm)

{

	list_del_init(&vm->list);

	list_add_tail(&vm->list, &rdev->vm_manager.lru_vm);

}

/**

 * radeon_vm_grab_id - allocate the next free VMID

 *

 * @rdev: radeon_device pointer

 * @vm: vm to allocate id for

 * @ring: ring we want to submit job to

 *

 * Allocate an id for the vm (cayman+).

 * Returns the fence we need to sync to (if any).

 *

 * Global and local mutex must be locked!

 */

struct radeon_fence *radeon_vm_grab_id(struct radeon_device *rdev,

				       struct radeon_vm *vm, int ring)

{

	struct radeon_fence *best[RADEON_NUM_RINGS] = {};

	unsigned choices[2] = {};

	unsigned i;

	/* check if the id is still valid */

	if (vm->fence && vm->fence == rdev->vm_manager.active[vm->id])

		return NULL;

	/* we definately need to flush */

	radeon_fence_unref(&vm->last_flush);

	/* skip over VMID 0, since it is the system VM */

	for (i = 1; i < rdev->vm_manager.nvm; ++i) {

		struct radeon_fence *fence = rdev->vm_manager.active[i];

		if (fence == NULL) {

			/* found a free one */

			vm->id = i;

			return NULL;

		}

		if (radeon_fence_is_earlier(fence, best[fence->ring])) {

			best[fence->ring] = fence;

			choices[fence->ring == ring ? 0 : 1] = i;

		}

	}

	for (i = 0; i < 2; ++i) {

		if (choices[i]) {

			vm->id = choices[i];

			return rdev->vm_manager.active[choices[i]];

		}

	}

	/* should never happen */

	BUG();

	return NULL;

}

/**

 * radeon_vm_fence - remember fence for vm

 *

 * @rdev: radeon_device pointer

 * @vm: vm we want to fence

 * @fence: fence to remember

 *

 * Fence the vm (cayman+).

 * Set the fence used to protect page table and id.

 *

 * Global and local mutex must be locked!

 */

void radeon_vm_fence(struct radeon_device *rdev,

		     struct radeon_vm *vm,

		     struct radeon_fence *fence)

{

	radeon_fence_unref(&rdev->vm_manager.active[vm->id]);

	rdev->vm_manager.active[vm->id] = radeon_fence_ref(fence);

	radeon_fence_unref(&vm->fence);

	vm->fence = radeon_fence_ref(fence);

}

/**

 * radeon_vm_bo_find - find the bo_va for a specific vm & bo

 *

 * @vm: requested vm

 * @bo: requested buffer object

 *

 * Find @bo inside the requested vm (cayman+).

 * Search inside the @bos vm list for the requested vm

 * Returns the found bo_va or NULL if none is found

 *

 * Object has to be reserved!

 */

struct radeon_bo_va *radeon_vm_bo_find(struct radeon_vm *vm,

				       struct radeon_bo *bo)

{

	struct radeon_bo_va *bo_va;

	list_for_each_entry(bo_va, &bo->va, bo_list) {

		if (bo_va->vm == vm) {

			return bo_va;

		}

	}

	return NULL;

}

/**

 * radeon_vm_bo_add - add a bo to a specific vm

 *

 * @rdev: radeon_device pointer

 * @vm: requested vm

 * @bo: radeon buffer object

 *

 * Add @bo into the requested vm (cayman+).

 * Add @bo to the list of bos associated with the vm

 * Returns newly added bo_va or NULL for failure

 *

 * Object has to be reserved!

 */

struct radeon_bo_va *radeon_vm_bo_add(struct radeon_device *rdev,

				      struct radeon_vm *vm,

				      struct radeon_bo *bo)

{

	struct radeon_bo_va *bo_va;

	bo_va = kzalloc(sizeof(struct radeon_bo_va), GFP_KERNEL);

	if (bo_va == NULL) {

		return NULL;

	}

	bo_va->vm = vm;

	bo_va->bo = bo;

	bo_va->soffset = 0;

	bo_va->eoffset = 0;

	bo_va->flags = 0;

	bo_va->valid = false;

	bo_va->ref_count = 1;

	INIT_LIST_HEAD(&bo_va->bo_list);

	INIT_LIST_HEAD(&bo_va->vm_list);

	mutex_lock(&vm->mutex);

	list_add(&bo_va->vm_list, &vm->va);

	list_add_tail(&bo_va->bo_list, &bo->va);

	mutex_unlock(&vm->mutex);

	return bo_va;

}

/**

 * radeon_vm_bo_set_addr - set bos virtual address inside a vm

 *

 * @rdev: radeon_device pointer

 * @bo_va: bo_va to store the address

 * @soffset: requested offset of the buffer in the VM address space

 * @flags: attributes of pages (read/write/valid/etc.)

 *

 * Set offset of @bo_va (cayman+).

 * Validate and set the offset requested within the vm address space.

 * Returns 0 for success, error for failure.

 *

 * Object has to be reserved!

 */

int radeon_vm_bo_set_addr(struct radeon_device *rdev,

			  struct radeon_bo_va *bo_va,

			  uint64_t soffset,

			  uint32_t flags)

{

	uint64_t size = radeon_bo_size(bo_va->bo);

	uint64_t eoffset, last_offset = 0;

	struct radeon_vm *vm = bo_va->vm;

	struct radeon_bo_va *tmp;

	struct list_head *head;

	unsigned last_pfn;

	if (soffset) {

		/* make sure object fit at this offset */

		eoffset = soffset + size;

		if (soffset >= eoffset) {

			return -EINVAL;

		}

		last_pfn = eoffset / RADEON_GPU_PAGE_SIZE;

		if (last_pfn > rdev->vm_manager.max_pfn) {

			dev_err(rdev->dev, "va above limit (0x%08X > 0x%08X)\n",

				last_pfn, rdev->vm_manager.max_pfn);

			return -EINVAL;

		}

	} else {

		eoffset = last_pfn = 0;

	}

	mutex_lock(&vm->mutex);

	head = &vm->va;

	last_offset = 0;

	list_for_each_entry(tmp, &vm->va, vm_list) {

		if (bo_va == tmp) {

			/* skip over currently modified bo */

			continue;

		}

		if (soffset >= last_offset && eoffset <= tmp->soffset) {

			/* bo can be added before this one */

			break;

		}

		if (eoffset > tmp->soffset && soffset < tmp->eoffset) {

			/* bo and tmp overlap, invalid offset */

			dev_err(rdev->dev, "bo %p va 0x%08X conflict with (bo %p 0x%08X 0x%08X)\n",

				bo_va->bo, (unsigned)bo_va->soffset, tmp->bo,

				(unsigned)tmp->soffset, (unsigned)tmp->eoffset);

			mutex_unlock(&vm->mutex);

			return -EINVAL;

		}

		last_offset = tmp->eoffset;

		head = &tmp->vm_list;

	}

	bo_va->soffset = soffset;

	bo_va->eoffset = eoffset;

	bo_va->flags = flags;

	bo_va->valid = false;

	list_move(&bo_va->vm_list, head);

	mutex_unlock(&vm->mutex);

	return 0;

}

/**

 * radeon_vm_map_gart - get the physical address of a gart page

 *

 * @rdev: radeon_device pointer

 * @addr: the unmapped addr

 *

 * Look up the physical address of the page that the pte resolves

 * to (cayman+).

 * Returns the physical address of the page.

 */

uint64_t radeon_vm_map_gart(struct radeon_device *rdev, uint64_t addr)

{

	uint64_t result;

	/* page table offset */

	result = rdev->gart.pages_addr[addr >> PAGE_SHIFT];

	/* in case cpu page size != gpu page size*/

	result |= addr & (~PAGE_MASK);

	return result;

}

/**

 * radeon_vm_update_pdes - make sure that page directory is valid

 *

 * @rdev: radeon_device pointer

 * @vm: requested vm

 * @start: start of GPU address range

 * @end: end of GPU address range

 *

 * Allocates new page tables if necessary

 * and updates the page directory (cayman+).

 * Returns 0 for success, error for failure.

 *

 * Global and local mutex must be locked!

 */

static int radeon_vm_update_pdes(struct radeon_device *rdev,

				 struct radeon_vm *vm,

				 uint64_t start, uint64_t end)

{

	static const uint32_t incr = RADEON_VM_PTE_COUNT * 8;

	uint64_t last_pde = ~0, last_pt = ~0;

	unsigned count = 0;

	uint64_t pt_idx;

	int r;

	start = (start / RADEON_GPU_PAGE_SIZE) >> RADEON_VM_BLOCK_SIZE;

	end = (end / RADEON_GPU_PAGE_SIZE) >> RADEON_VM_BLOCK_SIZE;

	/* walk over the address space and update the page directory */

	for (pt_idx = start; pt_idx <= end; ++pt_idx) {

		uint64_t pde, pt;

		if (vm->page_tables[pt_idx])

			continue;

retry:

		r = radeon_sa_bo_new(rdev, &rdev->vm_manager.sa_manager,

				     &vm->page_tables[pt_idx],

				     RADEON_VM_PTE_COUNT * 8,

				     RADEON_GPU_PAGE_SIZE, false);

		if (r == -ENOMEM) {

			r = radeon_vm_evict(rdev, vm);

			if (r)

				return r;

			goto retry;

		} else if (r) {

			return r;

		}

		pde = vm->pd_gpu_addr + pt_idx * 8;

		pt = radeon_sa_bo_gpu_addr(vm->page_tables[pt_idx]);

		if (((last_pde + 8 * count) != pde) ||

		    ((last_pt + incr * count) != pt)) {

			if (count) {

				radeon_asic_vm_set_page(rdev, last_pde,

							last_pt, count, incr,

							RADEON_VM_PAGE_VALID);

			}

			count = 1;

			last_pde = pde;

			last_pt = pt;

		} else {

			++count;

		}

	}

	if (count) {

		radeon_asic_vm_set_page(rdev, last_pde, last_pt, count,

					incr, RADEON_VM_PAGE_VALID);

	}

	return 0;

}

/**

 * radeon_vm_update_ptes - make sure that page tables are valid

 *

 * @rdev: radeon_device pointer

 * @vm: requested vm

 * @start: start of GPU address range

 * @end: end of GPU address range

 * @dst: destination address to map to

 * @flags: mapping flags

 *

 * Update the page tables in the range @start - @end (cayman+).

 *

 * Global and local mutex must be locked!

 */

static void radeon_vm_update_ptes(struct radeon_device *rdev,

				  struct radeon_vm *vm,

				  uint64_t start, uint64_t end,

				  uint64_t dst, uint32_t flags)

{

	static const uint64_t mask = RADEON_VM_PTE_COUNT - 1;

	uint64_t last_pte = ~0, last_dst = ~0;

	unsigned count = 0;

	uint64_t addr;

	start = start / RADEON_GPU_PAGE_SIZE;

	end = end / RADEON_GPU_PAGE_SIZE;

	/* walk over the address space and update the page tables */

	for (addr = start; addr < end; ) {

		uint64_t pt_idx = addr >> RADEON_VM_BLOCK_SIZE;

		unsigned nptes;

		uint64_t pte;

		if ((addr & ~mask) == (end & ~mask))

			nptes = end - addr;

		else

			nptes = RADEON_VM_PTE_COUNT - (addr & mask);

		pte = radeon_sa_bo_gpu_addr(vm->page_tables[pt_idx]);

		pte += (addr & mask) * 8;

		if ((last_pte + 8 * count) != pte) {

			if (count) {

				radeon_asic_vm_set_page(rdev, last_pte,

							last_dst, count,

							RADEON_GPU_PAGE_SIZE,

							flags);

			}

			count = nptes;

			last_pte = pte;

			last_dst = dst;

		} else {

			count += nptes;

		}

		addr += nptes;

		dst += nptes * RADEON_GPU_PAGE_SIZE;

	}

	if (count) {

		radeon_asic_vm_set_page(rdev, last_pte,	last_dst, count,

					RADEON_GPU_PAGE_SIZE, flags);

	}

}

/**

 * radeon_vm_bo_update_pte - map a bo into the vm page table

 *

 * @rdev: radeon_device pointer

 * @vm: requested vm

 * @bo: radeon buffer object

 * @mem: ttm mem

 *

 * Fill in the page table entries for @bo (cayman+).

 * Returns 0 for success, -EINVAL for failure.

 *

 * Object have to be reserved & global and local mutex must be locked!

 */

int radeon_vm_bo_update_pte(struct radeon_device *rdev,

			    struct radeon_vm *vm,

			    struct radeon_bo *bo,

			    struct ttm_mem_reg *mem)

{

	unsigned ridx = rdev->asic->vm.pt_ring_index;

	struct radeon_ring *ring = &rdev->ring[ridx];

	struct radeon_semaphore *sem = NULL;

	struct radeon_bo_va *bo_va;

	unsigned nptes, npdes, ndw;

	uint64_t addr;

	int r;

	/* nothing to do if vm isn't bound */

	if (vm->page_directory == NULL)

		return 0;

	bo_va = radeon_vm_bo_find(vm, bo);

	if (bo_va == NULL) {

		dev_err(rdev->dev, "bo %p not in vm %p\n", bo, vm);

		return -EINVAL;

	}

	if (!bo_va->soffset) {

		dev_err(rdev->dev, "bo %p don't has a mapping in vm %p\n",

			bo, vm);

		return -EINVAL;

	}

	if ((bo_va->valid && mem) || (!bo_va->valid && mem == NULL))

		return 0;

	bo_va->flags &= ~RADEON_VM_PAGE_VALID;

	bo_va->flags &= ~RADEON_VM_PAGE_SYSTEM;

	if (mem) {

		addr = mem->start << PAGE_SHIFT;

		if (mem->mem_type != TTM_PL_SYSTEM) {

			bo_va->flags |= RADEON_VM_PAGE_VALID;

			bo_va->valid = true;

		}

		if (mem->mem_type == TTM_PL_TT) {

			bo_va->flags |= RADEON_VM_PAGE_SYSTEM;

		} else {

			addr += rdev->vm_manager.vram_base_offset;

		}

	} else {

		addr = 0;

		bo_va->valid = false;

	}

	if (vm->fence && radeon_fence_signaled(vm->fence)) {

		radeon_fence_unref(&vm->fence);

	}

	if (vm->fence && vm->fence->ring != ridx) {

		r = radeon_semaphore_create(rdev, &sem);

		if (r) {

			return r;

		}

	}

	nptes = radeon_bo_ngpu_pages(bo);

	/* assume two extra pdes in case the mapping overlaps the borders */

	npdes = (nptes >> RADEON_VM_BLOCK_SIZE) + 2;

	/* estimate number of dw needed */

	/* semaphore, fence and padding */

	ndw = 32;

	if (RADEON_VM_BLOCK_SIZE > 11)

		/* reserve space for one header for every 2k dwords */

		ndw += (nptes >> 11) * 4;

	else

		/* reserve space for one header for

		    every (1 << BLOCK_SIZE) entries */

		ndw += (nptes >> RADEON_VM_BLOCK_SIZE) * 4;

	/* reserve space for pte addresses */

	ndw += nptes * 2;

	/* reserve space for one header for every 2k dwords */

	ndw += (npdes >> 11) * 4;

	/* reserve space for pde addresses */

	ndw += npdes * 2;

	r = radeon_ring_lock(rdev, ring, ndw);