drm/amd/amdgpu: Code comments for the amdgpu_ttm.c driver. (v2) (50da5174) · Commits · e / devices / android_kernel_fairphone_FP4

drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c

+341 −7

Original line number	Diff line number	Diff line
		@@ -63,16 +63,44 @@ static void amdgpu_ttm_debugfs_fini(struct amdgpu_device *adev);
		/*
		* Global memory.
		*/

		/**
		* amdgpu_ttm_mem_global_init - Initialize and acquire reference to
		* memory object
		*
		* @ref: Object for initialization.
		*
		* This is called by drm_global_item_ref() when an object is being
		* initialized.
		*/
		static int amdgpu_ttm_mem_global_init(struct drm_global_reference *ref)
		{
		return ttm_mem_global_init(ref->object);
		}

		/**
		* amdgpu_ttm_mem_global_release - Drop reference to a memory object
		*
		* @ref: Object being removed
		*
		* This is called by drm_global_item_unref() when an object is being
		* released.
		*/
		static void amdgpu_ttm_mem_global_release(struct drm_global_reference *ref)
		{
		ttm_mem_global_release(ref->object);
		}

		/**
		* amdgpu_ttm_global_init - Initialize global TTM memory reference
		* structures.
		*
		* @adev: AMDGPU device for which the global structures need to be
		* registered.
		*
		* This is called as part of the AMDGPU ttm init from amdgpu_ttm_init()
		* during bring up.
		*/
		static int amdgpu_ttm_global_init(struct amdgpu_device *adev)
		{
		struct drm_global_reference *global_ref;
		@@ -80,7 +108,9 @@ static int amdgpu_ttm_global_init(struct amdgpu_device *adev)
		struct drm_sched_rq *rq;
		int r;

		/* ensure reference is false in case init fails */
		adev->mman.mem_global_referenced = false;

		global_ref = &adev->mman.mem_global_ref;
		global_ref->global_type = DRM_GLOBAL_TTM_MEM;
		global_ref->size = sizeof(struct ttm_mem_global);
		@@ -146,6 +176,18 @@ static int amdgpu_invalidate_caches(struct ttm_bo_device *bdev, uint32_t flags)
		return 0;
		}

		/**
		* amdgpu_init_mem_type - Initialize a memory manager for a specific
		* type of memory request.
		*
		* @bdev: The TTM BO device object (contains a reference to
		* amdgpu_device)
		* @type: The type of memory requested
		* @man:
		*
		* This is called by ttm_bo_init_mm() when a buffer object is being
		* initialized.
		*/
		static int amdgpu_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
		struct ttm_mem_type_manager *man)
		{
		@@ -161,6 +203,7 @@ static int amdgpu_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
		man->default_caching = TTM_PL_FLAG_CACHED;
		break;
		case TTM_PL_TT:
		/* GTT memory */
		man->func = &amdgpu_gtt_mgr_func;
		man->gpu_offset = adev->gmc.gart_start;
		man->available_caching = TTM_PL_MASK_CACHING;
		@@ -193,6 +236,14 @@ static int amdgpu_init_mem_type(struct ttm_bo_device *bdev, uint32_t type,
		return 0;
		}

		/**
		* 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)
		{
		@@ -204,12 +255,14 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo,
		.flags = TTM_PL_MASK_CACHING \| TTM_PL_FLAG_SYSTEM
		};

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

		/* Object isn't an AMDGPU object so ignore */
		if (!amdgpu_ttm_bo_is_amdgpu_bo(bo)) {
		placement->placement = &placements;
		placement->busy_placement = &placements;
		@@ -217,10 +270,12 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo,
		placement->num_busy_placement = 1;
		return;
		}

		abo = ttm_to_amdgpu_bo(bo);
		switch (bo->mem.mem_type) {
		case TTM_PL_VRAM:
		if (!adev->mman.buffer_funcs_enabled) {
		/* Move to system memory */
		amdgpu_ttm_placement_from_domain(abo, AMDGPU_GEM_DOMAIN_CPU);
		} else if (adev->gmc.visible_vram_size < adev->gmc.real_vram_size &&
		!(abo->flags & AMDGPU_GEM_CREATE_CPU_ACCESS_REQUIRED) &&
		@@ -238,6 +293,7 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo,
		abo->placement.busy_placement = &abo->placements[1];
		abo->placement.num_busy_placement = 1;
		} else {
		/* Move to GTT memory */
		amdgpu_ttm_placement_from_domain(abo, AMDGPU_GEM_DOMAIN_GTT);
		}
		break;
		@@ -248,6 +304,15 @@ static void amdgpu_evict_flags(struct ttm_buffer_object *bo,
		*placement = abo->placement;
		}

		/**
		* amdgpu_verify_access - Verify access for a mmap call
		*
		* @bo: The buffer object to map
		* @filp: The file pointer from the process performing the mmap
		*
		* This is called by ttm_bo_mmap() to verify whether a process
		* has the right to mmap a BO to their process space.
		*/
		static int amdgpu_verify_access(struct ttm_buffer_object bo, struct file filp)
		{
		struct amdgpu_bo *abo = ttm_to_amdgpu_bo(bo);
		@@ -265,6 +330,15 @@ static int amdgpu_verify_access(struct ttm_buffer_object bo, struct file filp)
		filp->private_data);
		}

		/**
		* amdgpu_move_null - Register memory for a buffer object
		*
		* @bo: The bo to assign the memory to
		* @new_mem: The memory to be assigned.
		*
		* Assign the memory from new_mem to the memory of the buffer object
		* bo.
		*/
		static void amdgpu_move_null(struct ttm_buffer_object *bo,
		struct ttm_mem_reg *new_mem)
		{
		@@ -275,6 +349,10 @@ static void amdgpu_move_null(struct ttm_buffer_object *bo,
		new_mem->mm_node = NULL;
		}

		/**
		* amdgpu_mm_node_addr - Compute the GPU relative offset of a GTT
		* buffer.
		*/
		static uint64_t amdgpu_mm_node_addr(struct ttm_buffer_object *bo,
		struct drm_mm_node *mm_node,
		struct ttm_mem_reg *mem)
		@@ -290,8 +368,9 @@ static uint64_t amdgpu_mm_node_addr(struct ttm_buffer_object *bo,

		/**
		* amdgpu_find_mm_node - Helper function finds the drm_mm_node
		* corresponding to @offset. It also modifies the offset to be
		* within the drm_mm_node returned
		* corresponding to @offset. It also modifies
		* the offset to be within the drm_mm_node
		* returned
		*/
		static struct drm_mm_node amdgpu_find_mm_node(struct ttm_mem_reg mem,
		unsigned long *offset)
		@@ -430,7 +509,12 @@ int amdgpu_ttm_copy_mem_to_mem(struct amdgpu_device *adev,
		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, bool no_wait_gpu,
		struct ttm_mem_reg *new_mem,
		@@ -465,6 +549,11 @@ static int amdgpu_move_blit(struct ttm_buffer_object *bo,
		return r;
		}

		/**
		* amdgpu_move_vram_ram - Copy VRAM buffer to RAM buffer
		*
		* Called by amdgpu_bo_move().
		*/
		static int amdgpu_move_vram_ram(struct ttm_buffer_object *bo, bool evict,
		struct ttm_operation_ctx *ctx,
		struct ttm_mem_reg *new_mem)
		@@ -477,6 +566,8 @@ static int amdgpu_move_vram_ram(struct ttm_buffer_object *bo, bool evict,
		int r;

		adev = amdgpu_ttm_adev(bo->bdev);

		/* create space/pages for new_mem in GTT space */
		tmp_mem = *new_mem;
		tmp_mem.mm_node = NULL;
		placement.num_placement = 1;
		@@ -491,25 +582,36 @@ static int amdgpu_move_vram_ram(struct ttm_buffer_object *bo, bool evict,
		return r;
		}

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

		/* Bind the memory to the GTT space */
		r = ttm_tt_bind(bo->ttm, &tmp_mem, ctx);
		if (unlikely(r)) {
		goto out_cleanup;
		}

		/* blit VRAM to GTT */
		r = amdgpu_move_blit(bo, true, ctx->no_wait_gpu, &tmp_mem, old_mem);
		if (unlikely(r)) {
		goto out_cleanup;
		}

		/* move BO (in tmp_mem) to new_mem */
		r = ttm_bo_move_ttm(bo, ctx, new_mem);
		out_cleanup:
		ttm_bo_mem_put(bo, &tmp_mem);
		return r;
		}

		/**
		* amdgpu_move_ram_vram - Copy buffer from RAM to VRAM
		*
		* Called by amdgpu_bo_move().
		*/
		static int amdgpu_move_ram_vram(struct ttm_buffer_object *bo, bool evict,
		struct ttm_operation_ctx *ctx,
		struct ttm_mem_reg *new_mem)
		@@ -522,6 +624,8 @@ static int amdgpu_move_ram_vram(struct ttm_buffer_object *bo, bool evict,
		int r;

		adev = amdgpu_ttm_adev(bo->bdev);

		/* make space in GTT for old_mem buffer */
		tmp_mem = *new_mem;
		tmp_mem.mm_node = NULL;
		placement.num_placement = 1;
		@@ -535,10 +639,14 @@ static int amdgpu_move_ram_vram(struct ttm_buffer_object *bo, bool evict,
		if (unlikely(r)) {
		return r;
		}

		/* move/bind old memory to GTT space */
		r = ttm_bo_move_ttm(bo, ctx, &tmp_mem);
		if (unlikely(r)) {
		goto out_cleanup;
		}

		/* copy to VRAM */
		r = amdgpu_move_blit(bo, true, ctx->no_wait_gpu, new_mem, old_mem);
		if (unlikely(r)) {
		goto out_cleanup;
		@@ -548,6 +656,11 @@ static int amdgpu_move_ram_vram(struct ttm_buffer_object *bo, bool evict,
		return r;
		}

		/**
		* 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_mem_reg *new_mem)
		@@ -613,6 +726,11 @@ static int amdgpu_bo_move(struct ttm_buffer_object *bo, bool evict,
		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_bo_device bdev, struct ttm_mem_reg mem)
		{
		struct ttm_mem_type_manager *man = &bdev->man[mem->mem_type];
		@@ -690,6 +808,14 @@ struct amdgpu_ttm_tt {
		uint32_t last_set_pages;
		};

		/**
		* amdgpu_ttm_tt_get_user_pages - Pin pages of memory pointed to
		* by a USERPTR pointer to memory
		*
		* Called by amdgpu_gem_userptr_ioctl() and amdgpu_cs_parser_bos().
		* This provides a wrapper around the get_user_pages() call to provide
		* device accessible pages that back user memory.
		*/
		int amdgpu_ttm_tt_get_user_pages(struct ttm_tt ttm, struct page *pages)
		{
		struct amdgpu_ttm_tt gtt = (void )ttm;
		@@ -719,6 +845,7 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt ttm, struct page *pages)
		}
		}

		/* loop enough times using contiguous pages of memory */
		do {
		unsigned num_pages = ttm->num_pages - pinned;
		uint64_t userptr = gtt->userptr + pinned * PAGE_SIZE;
		@@ -757,6 +884,14 @@ int amdgpu_ttm_tt_get_user_pages(struct ttm_tt ttm, struct page *pages)
		return r;
		}

		/**
		* 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 page *pages)
		{
		struct amdgpu_ttm_tt gtt = (void )ttm;
		@@ -771,6 +906,11 @@ void amdgpu_ttm_tt_set_user_pages(struct ttm_tt ttm, struct page *pages)
		}
		}

		/**
		* amdgpu_ttm_tt_mark_user_page - Mark pages as dirty
		*
		* Called while unpinning userptr pages
		*/
		void amdgpu_ttm_tt_mark_user_pages(struct ttm_tt *ttm)
		{
		struct amdgpu_ttm_tt gtt = (void )ttm;
		@@ -789,7 +929,12 @@ void amdgpu_ttm_tt_mark_user_pages(struct ttm_tt *ttm)
		}
		}

		/* prepare the sg table with the user pages */
		/**
		* 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_tt *ttm)
		{
		struct amdgpu_device *adev = amdgpu_ttm_adev(ttm->bdev);
		@@ -801,17 +946,20 @@ static int amdgpu_ttm_tt_pin_userptr(struct ttm_tt *ttm)
		enum dma_data_direction direction = write ?
		DMA_BIDIRECTIONAL : DMA_TO_DEVICE;

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

		/* Map SG to device */
		r = -ENOMEM;
		nents = dma_map_sg(adev->dev, ttm->sg->sgl, ttm->sg->nents, direction);
		if (nents != ttm->sg->nents)
		goto release_sg;

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

		@@ -822,6 +970,9 @@ static int amdgpu_ttm_tt_pin_userptr(struct ttm_tt *ttm)
		return r;
		}

		/**
		* amdgpu_ttm_tt_unpin_userptr - Unpin and unmap userptr pages
		*/
		static void amdgpu_ttm_tt_unpin_userptr(struct ttm_tt *ttm)
		{
		struct amdgpu_device *adev = amdgpu_ttm_adev(ttm->bdev);
		@@ -835,9 +986,10 @@ static void amdgpu_ttm_tt_unpin_userptr(struct ttm_tt *ttm)
		if (!ttm->sg->sgl)
		return;

		/* free the sg table and pages again */
		/* unmap the pages mapped to the device */
		dma_unmap_sg(adev->dev, ttm->sg->sgl, ttm->sg->nents, direction);

		/* mark the pages as dirty */
		amdgpu_ttm_tt_mark_user_pages(ttm);

		sg_free_table(ttm->sg);
		@@ -882,6 +1034,12 @@ int amdgpu_ttm_gart_bind(struct amdgpu_device *adev,
		return r;
		}

		/**
		* 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_tt *ttm,
		struct ttm_mem_reg *bo_mem)
		{
		@@ -912,7 +1070,10 @@ static int amdgpu_ttm_backend_bind(struct ttm_tt *ttm,
		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;
		r = amdgpu_gart_bind(adev, gtt->offset, ttm->num_pages,
		ttm->pages, gtt->ttm.dma_address, flags);
		@@ -923,6 +1084,9 @@ static int amdgpu_ttm_backend_bind(struct ttm_tt *ttm,
		return r;
		}

		/**
		* amdgpu_ttm_alloc_gart - Allocate GART memory for buffer object
		*/
		int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
		{
		struct amdgpu_device *adev = amdgpu_ttm_adev(bo->bdev);
		@@ -938,6 +1102,7 @@ int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
		amdgpu_gtt_mgr_has_gart_addr(&bo->mem))
		return 0;

		/* allocate GTT space */
		tmp = bo->mem;
		tmp.mm_node = NULL;
		placement.num_placement = 1;
		@@ -953,7 +1118,10 @@ int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
		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;
		r = amdgpu_ttm_gart_bind(adev, bo, flags);
		if (unlikely(r)) {
		@@ -969,6 +1137,12 @@ int amdgpu_ttm_alloc_gart(struct ttm_buffer_object *bo)
		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.
		*/
		int amdgpu_ttm_recover_gart(struct ttm_buffer_object *tbo)
		{
		struct amdgpu_device *adev = amdgpu_ttm_adev(tbo->bdev);
		@@ -984,12 +1158,19 @@ int amdgpu_ttm_recover_gart(struct ttm_buffer_object *tbo)
		return r;
		}

		/**
		* 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 int amdgpu_ttm_backend_unbind(struct ttm_tt *ttm)
		{
		struct amdgpu_device *adev = amdgpu_ttm_adev(ttm->bdev);
		struct amdgpu_ttm_tt gtt = (void )ttm;
		int r;

		/* if the pages have userptr pinning then clear that first */
		if (gtt->userptr)
		amdgpu_ttm_tt_unpin_userptr(ttm);

		@@ -1021,6 +1202,13 @@ static struct ttm_backend_func amdgpu_backend_func = {
		.destroy = &amdgpu_ttm_backend_destroy,
		};

		/**
		* 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
		*
		* Called by ttm_tt_create().
		*/
		static struct ttm_tt amdgpu_ttm_tt_create(struct ttm_buffer_object bo,
		uint32_t page_flags)
		{
		@@ -1034,6 +1222,8 @@ static struct ttm_tt amdgpu_ttm_tt_create(struct ttm_buffer_object bo,
		return NULL;
		}
		gtt->ttm.ttm.func = &amdgpu_backend_func;

		/* allocate space for the uninitialized page entries */
		if (ttm_sg_tt_init(&gtt->ttm, bo, page_flags)) {
		kfree(gtt);
		return NULL;
		@@ -1041,6 +1231,12 @@ static struct ttm_tt amdgpu_ttm_tt_create(struct ttm_buffer_object bo,
		return &gtt->ttm.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_tt *ttm,
		struct ttm_operation_ctx *ctx)
		{
		@@ -1048,6 +1244,7 @@ static int amdgpu_ttm_tt_populate(struct ttm_tt *ttm,
		struct amdgpu_ttm_tt gtt = (void )ttm;
		bool slave = !!(ttm->page_flags & TTM_PAGE_FLAG_SG);

		/* user pages are bound by amdgpu_ttm_tt_pin_userptr() */
		if (gtt && gtt->userptr) {
		ttm->sg = kzalloc(sizeof(struct sg_table), GFP_KERNEL);
		if (!ttm->sg)
		@@ -1072,9 +1269,17 @@ static int amdgpu_ttm_tt_populate(struct ttm_tt *ttm,
		}
		#endif

		/* fall back to generic helper to populate the page array
		* and map them to the device */
		return ttm_populate_and_map_pages(adev->dev, &gtt->ttm, ctx);
		}

		/**
		* 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_tt *ttm)
		{
		struct amdgpu_device *adev;
		@@ -1100,9 +1305,21 @@ static void amdgpu_ttm_tt_unpopulate(struct ttm_tt *ttm)
		}
		#endif

		/* fall back to generic helper to unmap and unpopulate array */
		ttm_unmap_and_unpopulate_pages(adev->dev, &gtt->ttm);
		}

		/**
		* amdgpu_ttm_tt_set_userptr - Initialize userptr GTT ttm_tt
		* for the current task
		*
		* @ttm: The ttm_tt object to bind this userptr object to
		* @addr: The address in the current tasks VM space to use
		* @flags: Requirements of userptr object.
		*
		* Called by amdgpu_gem_userptr_ioctl() to bind userptr pages
		* to current task
		*/
		int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
		uint32_t flags)
		{
		@@ -1127,6 +1344,9 @@ int amdgpu_ttm_tt_set_userptr(struct ttm_tt *ttm, uint64_t addr,
		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 = (void )ttm;
		@@ -1140,6 +1360,12 @@ struct mm_struct amdgpu_ttm_tt_get_usermm(struct ttm_tt ttm)
		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)
		{
		@@ -1150,10 +1376,16 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
		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.ttm.num_pages * PAGE_SIZE;
		if (gtt->userptr > end \|\| gtt->userptr + size <= start)
		return false;

		/* Search the lists of tasks that hold this mapping and see
		* if current is one of them. If it is return false.
		*/
		spin_lock(&gtt->guptasklock);
		list_for_each_entry(entry, &gtt->guptasks, list) {
		if (entry->task == current) {
		@@ -1168,6 +1400,10 @@ bool amdgpu_ttm_tt_affect_userptr(struct ttm_tt *ttm, unsigned long start,
		return true;
		}

		/**
		* amdgpu_ttm_tt_userptr_invalidated - Has the ttm_tt object been
		* invalidated?
		*/
		bool amdgpu_ttm_tt_userptr_invalidated(struct ttm_tt *ttm,
		int *last_invalidated)
		{
		@@ -1178,6 +1414,12 @@ bool amdgpu_ttm_tt_userptr_invalidated(struct ttm_tt *ttm,
		return prev_invalidated != *last_invalidated;
		}

		/**
		* amdgpu_ttm_tt_userptr_needs_pages - Have the pages backing this
		* ttm_tt object been invalidated
		* since the last time they've
		* been set?
		*/
		bool amdgpu_ttm_tt_userptr_needs_pages(struct ttm_tt *ttm)
		{
		struct amdgpu_ttm_tt gtt = (void )ttm;
		@@ -1188,6 +1430,9 @@ bool amdgpu_ttm_tt_userptr_needs_pages(struct ttm_tt *ttm)
		return atomic_read(&gtt->mmu_invalidations) != gtt->last_set_pages;
		}

		/**
		* 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 = (void )ttm;
		@@ -1198,6 +1443,12 @@ bool amdgpu_ttm_tt_is_readonly(struct ttm_tt *ttm)
		return !!(gtt->userflags & AMDGPU_GEM_USERPTR_READONLY);
		}

		/**
		* amdgpu_ttm_tt_pte_flags - Compute PTE flags for ttm_tt object
		*
		* @ttm: The ttm_tt object to compute the flags for
		* @mem: The memory registry backing this ttm_tt object
		*/
		uint64_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device adev, struct ttm_tt ttm,
		struct ttm_mem_reg *mem)
		{
		@@ -1222,6 +1473,16 @@ uint64_t amdgpu_ttm_tt_pte_flags(struct amdgpu_device adev, struct ttm_tt ttm,
		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)
		{
		@@ -1268,6 +1529,19 @@ static bool amdgpu_ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
		return ttm_bo_eviction_valuable(bo, place);
		}

		/**
		* 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)
		@@ -1444,13 +1718,22 @@ static int amdgpu_ttm_fw_reserve_vram_init(struct amdgpu_device *adev)
		adev->fw_vram_usage.reserved_bo = NULL;
		return r;
		}

		/**
		* 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;
		u64 vis_vram_limit;

		/* initialize global references for vram/gtt */
		r = amdgpu_ttm_global_init(adev);
		if (r) {
		return r;
		@@ -1471,6 +1754,7 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
		/* We opt to avoid OOM on system pages allocations */
		adev->mman.bdev.no_retry = true;

		/* Initialize VRAM pool with all of VRAM divided into pages */
		r = ttm_bo_init_mm(&adev->mman.bdev, TTM_PL_VRAM,
		adev->gmc.real_vram_size >> PAGE_SHIFT);
		if (r) {
		@@ -1500,6 +1784,10 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
		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.stolen_size) {
		r = amdgpu_bo_create_kernel(adev, adev->gmc.stolen_size, PAGE_SIZE,
		AMDGPU_GEM_DOMAIN_VRAM,
		@@ -1511,6 +1799,8 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
		DRM_INFO("amdgpu: %uM of VRAM memory ready\n",
		(unsigned) (adev->gmc.real_vram_size / (1024 * 1024)));

		/* Compute GTT size, either bsaed on 3/4th the size of RAM size
		* or whatever the user passed on module init */
		if (amdgpu_gtt_size == -1) {
		struct sysinfo si;

		@@ -1521,6 +1811,8 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
		}
		else
		gtt_size = (uint64_t)amdgpu_gtt_size << 20;

		/* Initialize GTT memory pool */
		r = ttm_bo_init_mm(&adev->mman.bdev, TTM_PL_TT, gtt_size >> PAGE_SHIFT);
		if (r) {
		DRM_ERROR("Failed initializing GTT heap.\n");
		@@ -1529,6 +1821,7 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
		DRM_INFO("amdgpu: %uM of GTT memory ready.\n",
		(unsigned)(gtt_size / (1024 * 1024)));

		/* Initialize various on-chip memory pools */
		adev->gds.mem.total_size = adev->gds.mem.total_size << AMDGPU_GDS_SHIFT;
		adev->gds.mem.gfx_partition_size = adev->gds.mem.gfx_partition_size << AMDGPU_GDS_SHIFT;
		adev->gds.mem.cs_partition_size = adev->gds.mem.cs_partition_size << AMDGPU_GDS_SHIFT;
		@@ -1568,6 +1861,7 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
		}
		}

		/* Register debugfs entries for amdgpu_ttm */
		r = amdgpu_ttm_debugfs_init(adev);
		if (r) {
		DRM_ERROR("Failed to init debugfs\n");
		@@ -1576,11 +1870,19 @@ int amdgpu_ttm_init(struct amdgpu_device *adev)
		return 0;
		}

		/**
		* amdgpu_ttm_late_init - Handle any late initialization for
		* amdgpu_ttm
		*/
		void amdgpu_ttm_late_init(struct amdgpu_device *adev)
		{
		/* return the VGA stolen memory (if any) back to VRAM */
		amdgpu_bo_free_kernel(&adev->stolen_vga_memory, NULL, NULL);
		}

		/**
		* amdgpu_ttm_fini - De-initialize the TTM memory pools
		*/
		void amdgpu_ttm_fini(struct amdgpu_device *adev)
		{
		if (!adev->mman.initialized)
		@@ -1908,6 +2210,11 @@ static const struct drm_info_list amdgpu_ttm_debugfs_list[] = {
		#endif
		};

		/**
		* 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)
		{
		@@ -1947,6 +2254,11 @@ static ssize_t amdgpu_ttm_vram_read(struct file f, char __user buf,
		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)
		{
		@@ -1995,6 +2307,9 @@ static const struct file_operations amdgpu_ttm_vram_fops = {

		#ifdef CONFIG_DRM_AMDGPU_GART_DEBUGFS

		/**
		* amdgpu_ttm_gtt_read - Linear read access to GTT memory
		*/
		static ssize_t amdgpu_ttm_gtt_read(struct file f, char __user buf,
		size_t size, loff_t *pos)
		{
		@@ -2042,6 +2357,13 @@ static const struct file_operations amdgpu_ttm_gtt_fops = {

		#endif

		/**
		* 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)
		{
		@@ -2050,6 +2372,7 @@ static ssize_t amdgpu_iomem_read(struct file f, char __user buf,
		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) {
		@@ -2062,6 +2385,10 @@ static ssize_t amdgpu_iomem_read(struct file f, char __user buf,

		bytes = bytes < size ? 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;
		@@ -2086,6 +2413,13 @@ static ssize_t amdgpu_iomem_read(struct file f, char __user buf,
		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)
		{