drm/xe: Unify the initialization of VRAM regions

Currently in the drivers we have defined VRAM regions per device and per
tile. Initialization of these regions is done in two completely different
ways. To simplify the logic of the code and make it easier to add new
regions in the future, let's unify the way we initialize VRAM regions.

v2:
- fix doc comments in struct xe_vram_region
- remove unnecessary includes (Jani)
v3:
- move code from xe_vram_init_regions_managers to xe_tile_init_noalloc
(Matthew)
- replace ioremap_wc to devm_ioremap_wc for mapping VRAM BAR
(Matthew)
- Replace the tile id parameter with vram region in the xe_pf_begin
function.
v4:
- remove tile back pointer from struct xe_vram_region
- add new back pointers: xe and migarte to xe_vram_region

Signed-off-by: Piotr Piórkowski <[e-mail]>
Cc: Stuart Summers <[e-mail]>
Cc: Matthew Auld <[e-mail]>
Cc: Jani Nikula <[e-mail]>
Reviewed-by: Matthew Auld <[e-mail]> # rev3
Acked-by: Matthew Brost <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Lucas De Marchi <[e-mail]>

drivers/gpu/drm/xe/xe_bo.h

···
 #include "xe_macros.h"
 #include "xe_vm_types.h"
 #include "xe_vm.h"
+#include "xe_vram_types.h"
 
 #define XE_DEFAULT_GTT_SIZE_MB          3072ULL /* 3GB by default */
 
···
 #define XE_BO_FLAG_VRAM_MASK		(XE_BO_FLAG_VRAM0 | XE_BO_FLAG_VRAM1)
 /* -- */
 #define XE_BO_FLAG_STOLEN		BIT(4)
+#define XE_BO_FLAG_VRAM(vram)		(XE_BO_FLAG_VRAM0 << ((vram)->id))
 #define XE_BO_FLAG_VRAM_IF_DGFX(tile)	(IS_DGFX(tile_to_xe(tile)) ? \
-					 XE_BO_FLAG_VRAM0 << (tile)->id : \
+					 XE_BO_FLAG_VRAM((tile)->mem.vram) : \
 					 XE_BO_FLAG_SYSTEM)
 #define XE_BO_FLAG_GGTT			BIT(5)
 #define XE_BO_FLAG_IGNORE_MIN_PAGE_SIZE BIT(6)

drivers/gpu/drm/xe/xe_gt_pagefault.c

···
 #include "xe_svm.h"
 #include "xe_trace_bo.h"
 #include "xe_vm.h"
+#include "xe_vram_types.h"
 
 struct pagefault {
 	u64 page_addr;
···
 }
 
 static int xe_pf_begin(struct drm_exec *exec, struct xe_vma *vma,
-		       bool atomic, unsigned int id)
+		       bool atomic, struct xe_vram_region *vram)
 {
 	struct xe_bo *bo = xe_vma_bo(vma);
 	struct xe_vm *vm = xe_vma_vm(vma);
···
 	if (err)
 		return err;
 
-	if (atomic && IS_DGFX(vm->xe)) {
+	if (atomic && vram) {
+		xe_assert(vm->xe, IS_DGFX(vm->xe));
+
 		if (xe_vma_is_userptr(vma)) {
 			err = -EACCES;
 			return err;
 		}
 
 		/* Migrate to VRAM, move should invalidate the VMA first */
-		err = xe_bo_migrate(bo, XE_PL_VRAM0 + id);
+		err = xe_bo_migrate(bo, vram->placement);
 		if (err)
 			return err;
 	} else if (bo) {
···
 	/* Lock VM and BOs dma-resv */
 	drm_exec_init(&exec, 0, 0);
 	drm_exec_until_all_locked(&exec) {
-		err = xe_pf_begin(&exec, vma, atomic, tile->id);
+		err = xe_pf_begin(&exec, vma, atomic, tile->mem.vram);
 		drm_exec_retry_on_contention(&exec);
 		if (xe_vm_validate_should_retry(&exec, err, &end))
 			err = -EAGAIN;
···
 	/* Lock VM and BOs dma-resv */
 	drm_exec_init(&exec, 0, 0);
 	drm_exec_until_all_locked(&exec) {
-		ret = xe_pf_begin(&exec, vma, true, tile->id);
+		ret = xe_pf_begin(&exec, vma, true, tile->mem.vram);
 		drm_exec_retry_on_contention(&exec);
 		if (ret)
 			break;

drivers/gpu/drm/xe/xe_query.c

···
 #include "xe_oa.h"
 #include "xe_pxp.h"
 #include "xe_ttm_vram_mgr.h"
+#include "xe_vram_types.h"
 #include "xe_wa.h"
 
 static const u16 xe_to_user_engine_class[] = {
···
 			gt_list->gt_list[iter].near_mem_regions = 0x1;
 		else
 			gt_list->gt_list[iter].near_mem_regions =
-				BIT(gt_to_tile(gt)->id) << 1;
+				BIT(gt_to_tile(gt)->mem.vram->id) << 1;
 		gt_list->gt_list[iter].far_mem_regions = xe->info.mem_region_mask ^
 			gt_list->gt_list[iter].near_mem_regions;
 

drivers/gpu/drm/xe/xe_svm.c

···
 				      struct page *page)
 {
 	u64 dpa;
-	struct xe_tile *tile = vr->tile;
 	u64 pfn = page_to_pfn(page);
 	u64 offset;
 
-	xe_tile_assert(tile, is_device_private_page(page));
-	xe_tile_assert(tile, (pfn << PAGE_SHIFT) >= vr->hpa_base);
+	xe_assert(vr->xe, is_device_private_page(page));
+	xe_assert(vr->xe, (pfn << PAGE_SHIFT) >= vr->hpa_base);
 
 	offset = (pfn << PAGE_SHIFT) - vr->hpa_base;
 	dpa = vr->dpa_base + offset;
···
 		       unsigned long npages, const enum xe_svm_copy_dir dir)
 {
 	struct xe_vram_region *vr = NULL;
-	struct xe_tile *tile;
+	struct xe_device *xe;
 	struct dma_fence *fence = NULL;
 	unsigned long i;
 #define XE_VRAM_ADDR_INVALID	~0x0ull
···
 
 		if (!vr && spage) {
 			vr = page_to_vr(spage);
-			tile = vr->tile;
+			xe = vr->xe;
 		}
 		XE_WARN_ON(spage && page_to_vr(spage) != vr);
 
···
 
 			if (vram_addr != XE_VRAM_ADDR_INVALID) {
 				if (sram) {
-					vm_dbg(&tile->xe->drm,
+					vm_dbg(&xe->drm,
 					       "COPY TO SRAM - 0x%016llx -> 0x%016llx, NPAGES=%ld",
 					       vram_addr, (u64)dma_addr[pos], i - pos + incr);
-					__fence = xe_migrate_from_vram(tile->migrate,
+					__fence = xe_migrate_from_vram(vr->migrate,
 								       i - pos + incr,
 								       vram_addr,
 								       dma_addr + pos);
 				} else {
-					vm_dbg(&tile->xe->drm,
+					vm_dbg(&xe->drm,
 					       "COPY TO VRAM - 0x%016llx -> 0x%016llx, NPAGES=%ld",
 					       (u64)dma_addr[pos], vram_addr, i - pos + incr);
-					__fence = xe_migrate_to_vram(tile->migrate,
+					__fence = xe_migrate_to_vram(vr->migrate,
 								     i - pos + incr,
 								     dma_addr + pos,
 								     vram_addr);
···
 			/* Extra mismatched device page, copy it */
 			if (!match && last && vram_addr != XE_VRAM_ADDR_INVALID) {
 				if (sram) {
-					vm_dbg(&tile->xe->drm,
+					vm_dbg(&xe->drm,
 					       "COPY TO SRAM - 0x%016llx -> 0x%016llx, NPAGES=%d",
 					       vram_addr, (u64)dma_addr[pos], 1);
-					__fence = xe_migrate_from_vram(tile->migrate, 1,
+					__fence = xe_migrate_from_vram(vr->migrate, 1,
 								       vram_addr,
 								       dma_addr + pos);
 				} else {
-					vm_dbg(&tile->xe->drm,
+					vm_dbg(&xe->drm,
 					       "COPY TO VRAM - 0x%016llx -> 0x%016llx, NPAGES=%d",
 					       (u64)dma_addr[pos], vram_addr, 1);
-					__fence = xe_migrate_to_vram(tile->migrate, 1,
+					__fence = xe_migrate_to_vram(vr->migrate, 1,
 								     dma_addr + pos,
 								     vram_addr);
 				}
···
 	return PHYS_PFN(offset + vr->hpa_base);
 }
 
-static struct drm_buddy *tile_to_buddy(struct xe_tile *tile)
+static struct drm_buddy *vram_to_buddy(struct xe_vram_region *vram)
 {
-	return &tile->mem.vram->ttm.mm;
+	return &vram->ttm.mm;
 }
 
 static int xe_svm_populate_devmem_pfn(struct drm_pagemap_devmem *devmem_allocation,
···
 
 	list_for_each_entry(block, blocks, link) {
 		struct xe_vram_region *vr = block->private;
-		struct xe_tile *tile = vr->tile;
-		struct drm_buddy *buddy = tile_to_buddy(tile);
+		struct drm_buddy *buddy = vram_to_buddy(vr);
 		u64 block_pfn = block_offset_to_pfn(vr, drm_buddy_block_offset(block));
 		int i;
 
···
 				      unsigned long timeslice_ms)
 {
 	struct xe_vram_region *vr = container_of(dpagemap, typeof(*vr), dpagemap);
-	struct xe_tile *tile = vr->tile;
-	struct xe_device *xe = tile_to_xe(tile);
+	struct xe_device *xe = vr->xe;
 	struct device *dev = xe->drm.dev;
 	struct drm_buddy_block *block;
 	struct list_head *blocks;
···
 	xe_pm_runtime_get(xe);
 
  retry:
-	bo = xe_bo_create_locked(tile_to_xe(tile), NULL, NULL, end - start,
+	bo = xe_bo_create_locked(vr->xe, NULL, NULL, end - start,
 				 ttm_bo_type_device,
-				 XE_BO_FLAG_VRAM_IF_DGFX(tile) |
+				 (IS_DGFX(xe) ? XE_BO_FLAG_VRAM(vr) : XE_BO_FLAG_SYSTEM) |
 				 XE_BO_FLAG_CPU_ADDR_MIRROR);
 	if (IS_ERR(bo)) {
 		err = PTR_ERR(bo);
···
 	}
 
 	drm_pagemap_devmem_init(&bo->devmem_allocation, dev, mm,
-				&dpagemap_devmem_ops,
-				&tile->mem.vram->dpagemap,
-				end - start);
+				&dpagemap_devmem_ops, dpagemap, end - start);
 
 	blocks = &to_xe_ttm_vram_mgr_resource(bo->ttm.resource)->blocks;
 	list_for_each_entry(block, blocks, link)

drivers/gpu/drm/xe/xe_tile.c

···
 
 #include <drm/drm_managed.h>
 
+#include "xe_bo.h"
 #include "xe_device.h"
 #include "xe_ggtt.h"
 #include "xe_gt.h"
···
 	if (!IS_DGFX(xe))
 		return 0;
 
-	vram = drmm_kzalloc(&xe->drm, sizeof(*vram), GFP_KERNEL);
-	if (!vram)
-		return -ENOMEM;
-
-	vram->tile = tile;
+	vram = xe_vram_region_alloc(xe, tile->id, XE_PL_VRAM0 + tile->id);
+	if (IS_ERR(vram))
+		return PTR_ERR(vram);
 	tile->mem.vram = vram;
 
 	return 0;
···
 }
 ALLOW_ERROR_INJECTION(xe_tile_init_early, ERRNO); /* See xe_pci_probe() */
 
-static int tile_ttm_mgr_init(struct xe_tile *tile)
-{
-	struct xe_device *xe = tile_to_xe(tile);
-	int err;
-
-	if (tile->mem.vram) {
-		err = xe_ttm_vram_mgr_init(tile, &tile->mem.vram->ttm);
-		if (err)
-			return err;
-		xe->info.mem_region_mask |= BIT(tile->id) << 1;
-	}
-
-	return 0;
-}
-
 /**
  * xe_tile_init_noalloc - Init tile up to the point where allocations can happen.
  * @tile: The tile to initialize.
···
 int xe_tile_init_noalloc(struct xe_tile *tile)
 {
 	struct xe_device *xe = tile_to_xe(tile);
-	int err;
-
-	err = tile_ttm_mgr_init(tile);
-	if (err)
-		return err;
 
 	xe_wa_apply_tile_workarounds(tile);
 
 	if (xe->info.has_usm && IS_DGFX(xe))
 		xe_devm_add(tile, tile->mem.vram);
+
+	if (IS_DGFX(xe) && !ttm_resource_manager_used(&tile->mem.vram->ttm.manager)) {
+		int err = xe_ttm_vram_mgr_init(xe, tile->mem.vram);
+
+		if (err)
+			return err;
+		xe->info.mem_region_mask |= BIT(tile->mem.vram->id) << 1;
+	}
 
 	return xe_tile_sysfs_init(tile);
 }

drivers/gpu/drm/xe/xe_ttm_vram_mgr.c

···
 	return drmm_add_action_or_reset(&xe->drm, ttm_vram_mgr_fini, mgr);
 }
 
-int xe_ttm_vram_mgr_init(struct xe_tile *tile, struct xe_ttm_vram_mgr *mgr)
+/**
+ * xe_ttm_vram_mgr_init - initialize TTM VRAM region
+ * @xe: pointer to Xe device
+ * @vram: pointer to xe_vram_region that contains the memory region attributes
+ *
+ * Initialize the Xe TTM for given @vram region using the given parameters.
+ *
+ * Returns 0 for success, negative error code otherwise.
+ */
+int xe_ttm_vram_mgr_init(struct xe_device *xe, struct xe_vram_region *vram)
 {
-	struct xe_device *xe = tile_to_xe(tile);
-	struct xe_vram_region *vram = tile->mem.vram;
-
-	return __xe_ttm_vram_mgr_init(xe, mgr, XE_PL_VRAM0 + tile->id,
+	return __xe_ttm_vram_mgr_init(xe, &vram->ttm, vram->placement,
 				      xe_vram_region_usable_size(vram),
 				      xe_vram_region_io_size(vram),
 				      PAGE_SIZE);

drivers/gpu/drm/xe/xe_ttm_vram_mgr.h

···
 enum dma_data_direction;
 struct xe_device;
 struct xe_tile;
+struct xe_vram_region;
 
 int __xe_ttm_vram_mgr_init(struct xe_device *xe, struct xe_ttm_vram_mgr *mgr,
 			   u32 mem_type, u64 size, u64 io_size,
 			   u64 default_page_size);
-int xe_ttm_vram_mgr_init(struct xe_tile *tile, struct xe_ttm_vram_mgr *mgr);
+int xe_ttm_vram_mgr_init(struct xe_device *xe, struct xe_vram_region *vram);
 int xe_ttm_vram_mgr_alloc_sgt(struct xe_device *xe,
 			      struct ttm_resource *res,
 			      u64 offset, u64 length,

drivers/gpu/drm/xe/xe_vram.c

···
 #include "xe_mmio.h"
 #include "xe_module.h"
 #include "xe_sriov.h"
+#include "xe_ttm_vram_mgr.h"
 #include "xe_vram.h"
 #include "xe_vram_types.h"
 
···
 	return true;
 }
 
-static int determine_lmem_bar_size(struct xe_device *xe)
+static int determine_lmem_bar_size(struct xe_device *xe, struct xe_vram_region *lmem_bar)
 {
 	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
 
···
 
 	resize_vram_bar(xe);
 
-	xe->mem.vram->io_start = pci_resource_start(pdev, LMEM_BAR);
-	xe->mem.vram->io_size = pci_resource_len(pdev, LMEM_BAR);
-	if (!xe->mem.vram->io_size)
+	lmem_bar->io_start = pci_resource_start(pdev, LMEM_BAR);
+	lmem_bar->io_size = pci_resource_len(pdev, LMEM_BAR);
+	if (!lmem_bar->io_size)
 		return -EIO;
 
 	/* XXX: Need to change when xe link code is ready */
-	xe->mem.vram->dpa_base = 0;
+	lmem_bar->dpa_base = 0;
 
 	/* set up a map to the total memory area. */
-	xe->mem.vram->mapping = devm_ioremap_wc(&pdev->dev, xe->mem.vram->io_start,
-						xe->mem.vram->io_size);
+	lmem_bar->mapping = devm_ioremap_wc(&pdev->dev, lmem_bar->io_start, lmem_bar->io_size);
 
 	return 0;
 }
···
 		tile->mem.vram->mapping = NULL;
 }
 
+struct xe_vram_region *xe_vram_region_alloc(struct xe_device *xe, u8 id, u32 placement)
+{
+	struct xe_vram_region *vram;
+	struct drm_device *drm = &xe->drm;
+
+	xe_assert(xe, id < xe->info.tile_count);
+
+	vram = drmm_kzalloc(drm, sizeof(*vram), GFP_KERNEL);
+	if (!vram)
+		return NULL;
+
+	vram->xe = xe;
+	vram->id = id;
+	vram->placement = placement;
+#if defined(CONFIG_DRM_XE_PAGEMAP)
+	vram->migrate = xe->tiles[id].migrate;
+#endif
+	return vram;
+}
+
+static void print_vram_region_info(struct xe_device *xe, struct xe_vram_region *vram)
+{
+	struct drm_device *drm = &xe->drm;
+
+	if (vram->io_size < vram->usable_size)
+		drm_info(drm, "Small BAR device\n");
+
+	drm_info(drm,
+		 "VRAM[%u]: Actual physical size %pa, usable size exclude stolen %pa, CPU accessible size %pa\n",
+		 vram->id, &vram->actual_physical_size, &vram->usable_size, &vram->io_size);
+	drm_info(drm, "VRAM[%u]: DPA range: [%pa-%llx], io range: [%pa-%llx]\n",
+		 vram->id, &vram->dpa_base, vram->dpa_base + (u64)vram->actual_physical_size,
+		 &vram->io_start, vram->io_start + (u64)vram->io_size);
+}
+
+static int vram_region_init(struct xe_device *xe, struct xe_vram_region *vram,
+			    struct xe_vram_region *lmem_bar, u64 offset, u64 usable_size,
+			    u64 region_size, resource_size_t remain_io_size)
+{
+	/* Check if VRAM region is already initialized */
+	if (vram->mapping)
+		return 0;
+
+	vram->actual_physical_size = region_size;
+	vram->io_start = lmem_bar->io_start + offset;
+	vram->io_size = min_t(u64, usable_size, remain_io_size);
+
+	if (!vram->io_size) {
+		drm_err(&xe->drm, "Tile without any CPU visible VRAM. Aborting.\n");
+		return -ENODEV;
+	}
+
+	vram->dpa_base = lmem_bar->dpa_base + offset;
+	vram->mapping = lmem_bar->mapping + offset;
+	vram->usable_size = usable_size;
+
+	print_vram_region_info(xe, vram);
+
+	return 0;
+}
+
 /**
  * xe_vram_probe() - Probe VRAM configuration
  * @xe: the &xe_device
···
 int xe_vram_probe(struct xe_device *xe)
 {
 	struct xe_tile *tile;
-	resource_size_t io_size;
+	struct xe_vram_region lmem_bar;
+	resource_size_t remain_io_size;
 	u64 available_size = 0;
 	u64 total_size = 0;
-	u64 tile_offset;
-	u64 tile_size;
-	u64 vram_size;
 	int err;
 	u8 id;
 
 	if (!IS_DGFX(xe))
 		return 0;
 
-	/* Get the size of the root tile's vram for later accessibility comparison */
-	tile = xe_device_get_root_tile(xe);
-	err = tile_vram_size(tile, &vram_size, &tile_size, &tile_offset);
+	err = determine_lmem_bar_size(xe, &lmem_bar);
 	if (err)
 		return err;
+	drm_info(&xe->drm, "VISIBLE VRAM: %pa, %pa\n", &lmem_bar.io_start, &lmem_bar.io_size);
 
-	err = determine_lmem_bar_size(xe);
-	if (err)
-		return err;
+	remain_io_size = lmem_bar.io_size;
 
-	drm_info(&xe->drm, "VISIBLE VRAM: %pa, %pa\n", &xe->mem.vram->io_start,
-		 &xe->mem.vram->io_size);
-
-	io_size = xe->mem.vram->io_size;
-
-	/* tile specific ranges */
 	for_each_tile(tile, xe, id) {
-		err = tile_vram_size(tile, &vram_size, &tile_size, &tile_offset);
+		u64 region_size;
+		u64 usable_size;
+		u64 tile_offset;
+
+		err = tile_vram_size(tile, &usable_size, &region_size, &tile_offset);
 		if (err)
 			return err;
 
-		tile->mem.vram->actual_physical_size = tile_size;
-		tile->mem.vram->io_start = xe->mem.vram->io_start + tile_offset;
-		tile->mem.vram->io_size = min_t(u64, vram_size, io_size);
+		total_size += region_size;
+		available_size += usable_size;
 
-		if (!tile->mem.vram->io_size) {
-			drm_err(&xe->drm, "Tile without any CPU visible VRAM. Aborting.\n");
-			return -ENODEV;
-		}
+		err = vram_region_init(xe, tile->mem.vram, &lmem_bar, tile_offset, usable_size,
+				       region_size, remain_io_size);
+		if (err)
+			return err;
 
-		tile->mem.vram->dpa_base = xe->mem.vram->dpa_base + tile_offset;
-		tile->mem.vram->usable_size = vram_size;
-		tile->mem.vram->mapping = xe->mem.vram->mapping + tile_offset;
-
-		if (tile->mem.vram->io_size < tile->mem.vram->usable_size)
-			drm_info(&xe->drm, "Small BAR device\n");
-		drm_info(&xe->drm,
-			 "VRAM[%u, %u]: Actual physical size %pa, usable size exclude stolen %pa, CPU accessible size %pa\n",
-			 id, tile->id, &tile->mem.vram->actual_physical_size,
-			 &tile->mem.vram->usable_size, &tile->mem.vram->io_size);
-		drm_info(&xe->drm, "VRAM[%u, %u]: DPA range: [%pa-%llx], io range: [%pa-%llx]\n",
-			 id, tile->id, &tile->mem.vram->dpa_base,
-			 tile->mem.vram->dpa_base + (u64)tile->mem.vram->actual_physical_size,
-			 &tile->mem.vram->io_start,
-			 tile->mem.vram->io_start + (u64)tile->mem.vram->io_size);
-
-		/* calculate total size using tile size to get the correct HW sizing */
-		total_size += tile_size;
-		available_size += vram_size;
-
-		if (total_size > xe->mem.vram->io_size) {
+		if (total_size > lmem_bar.io_size) {
 			drm_info(&xe->drm, "VRAM: %pa is larger than resource %pa\n",
-				 &total_size, &xe->mem.vram->io_size);
+				 &total_size, &lmem_bar.io_size);
 		}
 
-		io_size -= min_t(u64, tile_size, io_size);
+		remain_io_size -= min_t(u64, tile->mem.vram->actual_physical_size, remain_io_size);
 	}
 
-	xe->mem.vram->actual_physical_size = total_size;
-
-	drm_info(&xe->drm, "Total VRAM: %pa, %pa\n", &xe->mem.vram->io_start,
-		 &xe->mem.vram->actual_physical_size);
-	drm_info(&xe->drm, "Available VRAM: %pa, %pa\n", &xe->mem.vram->io_start,
-		 &available_size);
+	err = vram_region_init(xe, xe->mem.vram, &lmem_bar, 0, available_size, total_size,
+			       lmem_bar.io_size);
+	if (err)
+		return err;
 
 	return devm_add_action_or_reset(xe->drm.dev, vram_fini, xe);
 }

drivers/gpu/drm/xe/xe_vram.h

···
 
 int xe_vram_probe(struct xe_device *xe);
 
+struct xe_vram_region *xe_vram_region_alloc(struct xe_device *xe, u8 id, u32 placement);
+
 resource_size_t xe_vram_region_io_start(const struct xe_vram_region *vram);
 resource_size_t xe_vram_region_io_size(const struct xe_vram_region *vram);
 resource_size_t xe_vram_region_dpa_base(const struct xe_vram_region *vram);

drivers/gpu/drm/xe/xe_vram_types.h

···
 
 #include "xe_ttm_vram_mgr_types.h"
 
-struct xe_tile;
+struct xe_device;
+struct xe_migrate;
 
 /**
  * struct xe_vram_region - memory region structure
···
  * device, such as HBM memory or CXL extension memory.
  */
 struct xe_vram_region {
-	/** @tile: Back pointer to tile */
-	struct xe_tile *tile;
+	/** @xe: Back pointer to xe device */
+	struct xe_device *xe;
+	/**
+	 * @id: VRAM region instance id
+	 *
+	 * The value should be unique for VRAM region.
+	 */
+	u8 id;
 	/** @io_start: IO start address of this VRAM instance */
 	resource_size_t io_start;
 	/**
···
 	void __iomem *mapping;
 	/** @ttm: VRAM TTM manager */
 	struct xe_ttm_vram_mgr ttm;
+	/** @placement: TTM placement dedicated for this region */
+	u32 placement;
 #if IS_ENABLED(CONFIG_DRM_XE_PAGEMAP)
+	/** @migrate: Back pointer to migrate */
+	struct xe_migrate *migrate;
 	/** @pagemap: Used to remap device memory as ZONE_DEVICE */
 	struct dev_pagemap pagemap;
 	/**