drm/xe/svm: Consult madvise preferred location in prefetch

When prefetch region is DRM_XE_CONSULT_MEM_ADVISE_PREF_LOC, prefetch svm
ranges to preferred location provided by madvise.

v2 (Matthew Brost)
- Fix region, devmem_fd usages
- consult madvise is applicable for other vma's too.

v3
- Fix atomic handling

v4
- Fix xe_svm_range_validate to check for
  DRM_XE_CONSULT_MEM_ADVISE_PREF_LOC too.

Cc: Matthew Brost <matthew.brost@intel.com>
Reviewed-by: Matthew Brost <matthew.brost@intel.com>
Link: https://lore.kernel.org/r/20250821173104.3030148-14-himal.prasad.ghimiray@intel.com
Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>

2 files changed, 35 insertions, 19 deletions

diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index 7bbf12742606..c765c96b9bde 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -38,6 +38,7 @@
 #include "xe_res_cursor.h"
 #include "xe_svm.h"
 #include "xe_sync.h"
+#include "xe_tile.h"
 #include "xe_trace_bo.h"
 #include "xe_wa.h"
 #include "xe_hmm.h"
@@ -2400,9 +2401,10 @@ vm_bind_ioctl_ops_create(struct xe_vm *vm, struct xe_vma_ops *vops,
 				__xe_vm_needs_clear_scratch_pages(vm, flags);
 		} else if (__op->op == DRM_GPUVA_OP_PREFETCH) {
 			struct xe_vma *vma = gpuva_to_vma(op->base.prefetch.va);
+			struct xe_tile *tile;
 			struct xe_svm_range *svm_range;
 			struct drm_gpusvm_ctx ctx = {};
-			struct xe_tile *tile;
+			struct drm_pagemap *dpagemap;
 			u8 id, tile_mask = 0;
 			u32 i;
 
@@ -2419,8 +2421,24 @@ vm_bind_ioctl_ops_create(struct xe_vm *vm, struct xe_vma_ops *vops,
 				tile_mask |= 0x1 << id;
 
 			xa_init_flags(&op->prefetch_range.range, XA_FLAGS_ALLOC);
-			op->prefetch_range.region = prefetch_region;
 			op->prefetch_range.ranges_count = 0;
+			tile = NULL;
+
+			if (prefetch_region == DRM_XE_CONSULT_MEM_ADVISE_PREF_LOC) {
+				dpagemap = xe_vma_resolve_pagemap(vma,
+								  xe_device_get_root_tile(vm->xe));
+				/*
+				 * TODO: Once multigpu support is enabled will need
+				 * something to dereference tile from dpagemap.
+				 */
+				if (dpagemap)
+					tile = xe_device_get_root_tile(vm->xe);
+			} else if (prefetch_region) {
+				tile = &vm->xe->tiles[region_to_mem_type[prefetch_region] -
+						      XE_PL_VRAM0];
+			}
+
+			op->prefetch_range.tile = tile;
 alloc_next_range:
 			svm_range = xe_svm_range_find_or_insert(vm, addr, vma, &ctx);
 
@@ -2439,7 +2457,7 @@ alloc_next_range:
 				goto unwind_prefetch_ops;
 			}
 
-			if (xe_svm_range_validate(vm, svm_range, tile_mask, !!prefetch_region)) {
+			if (xe_svm_range_validate(vm, svm_range, tile_mask, !!tile)) {
 				xe_svm_range_debug(svm_range, "PREFETCH - RANGE IS VALID");
 				goto check_next_range;
 			}
@@ -2935,30 +2953,26 @@ static int prefetch_ranges(struct xe_vm *vm, struct xe_vma_op *op)
 {
 	bool devmem_possible = IS_DGFX(vm->xe) && IS_ENABLED(CONFIG_DRM_XE_PAGEMAP);
 	struct xe_vma *vma = gpuva_to_vma(op->base.prefetch.va);
+	struct xe_tile *tile = op->prefetch_range.tile;
 	int err = 0;
 
 	struct xe_svm_range *svm_range;
 	struct drm_gpusvm_ctx ctx = {};
-	struct xe_tile *tile;
 	unsigned long i;
-	u32 region;
 
 	if (!xe_vma_is_cpu_addr_mirror(vma))
 		return 0;
 
-	region = op->prefetch_range.region;
-
 	ctx.read_only = xe_vma_read_only(vma);
 	ctx.devmem_possible = devmem_possible;
 	ctx.check_pages_threshold = devmem_possible ? SZ_64K : 0;
 
 	/* TODO: Threading the migration */
 	xa_for_each(&op->prefetch_range.range, i, svm_range) {
-		if (!region)
+		if (!tile)
 			xe_svm_range_migrate_to_smem(vm, svm_range);
 
-		if (xe_svm_range_needs_migrate_to_vram(svm_range, vma, region)) {
-			tile = &vm->xe->tiles[region_to_mem_type[region] - XE_PL_VRAM0];
+		if (xe_svm_range_needs_migrate_to_vram(svm_range, vma, !!tile)) {
 			err = xe_svm_alloc_vram(tile, svm_range, &ctx);
 			if (err) {
 				drm_dbg(&vm->xe->drm, "VRAM allocation failed, retry from userspace, asid=%u, gpusvm=%p, errno=%pe\n",
@@ -3021,12 +3035,11 @@ static int op_lock_and_prep(struct drm_exec *exec, struct xe_vm *vm,
 		struct xe_vma *vma = gpuva_to_vma(op->base.prefetch.va);
 		u32 region;
 
-		if (xe_vma_is_cpu_addr_mirror(vma))
-			region = op->prefetch_range.region;
-		else
+		if (!xe_vma_is_cpu_addr_mirror(vma)) {
 			region = op->prefetch.region;
-
-		xe_assert(vm->xe, region <= ARRAY_SIZE(region_to_mem_type));
+			xe_assert(vm->xe, region == DRM_XE_CONSULT_MEM_ADVISE_PREF_LOC ||
+				  region <= ARRAY_SIZE(region_to_mem_type));
+		}
 
 		err = vma_lock_and_validate(exec,
 					    gpuva_to_vma(op->base.prefetch.va),
@@ -3444,8 +3457,8 @@ static int vm_bind_ioctl_check_args(struct xe_device *xe, struct xe_vm *vm,
 				 op == DRM_XE_VM_BIND_OP_PREFETCH) ||
 		    XE_IOCTL_DBG(xe, prefetch_region &&
 				 op != DRM_XE_VM_BIND_OP_PREFETCH) ||
-		    XE_IOCTL_DBG(xe, !(BIT(prefetch_region) &
-				       xe->info.mem_region_mask)) ||
+		    XE_IOCTL_DBG(xe,  (prefetch_region != DRM_XE_CONSULT_MEM_ADVISE_PREF_LOC &&
+				       !(BIT(prefetch_region) & xe->info.mem_region_mask))) ||
 		    XE_IOCTL_DBG(xe, obj &&
 				 op == DRM_XE_VM_BIND_OP_UNMAP)) {
 			err = -EINVAL;
diff --git a/drivers/gpu/drm/xe/xe_vm_types.h b/drivers/gpu/drm/xe/xe_vm_types.h
index dde7218ceba6..5704f379c225 100644
--- a/drivers/gpu/drm/xe/xe_vm_types.h
+++ b/drivers/gpu/drm/xe/xe_vm_types.h
@@ -428,8 +428,11 @@ struct xe_vma_op_prefetch_range {
 	struct xarray range;
 	/** @ranges_count: number of svm ranges to map */
 	u32 ranges_count;
-	/** @region: memory region to prefetch to */
-	u32 region;
+	/**
+	 * @tile: Pointer to the tile structure containing memory to prefetch.
+	 *        NULL if prefetch requested region is smem
+	 */
+	struct xe_tile *tile;
 };
 
 /** enum xe_vma_op_flags - flags for VMA operation */