[RFC 23/29] drm/xe/madvise: Update migration policy based on preferred location

[Himal Prasad Ghimiray]

When the user sets the valid devmem_fd as a preferred location, GPU fault
will trigger migration to tile of device associated with devmem_fd.

If the user sets an invalid devmem_fd the preferred location is current
placement only.

Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
---
 drivers/gpu/drm/xe/xe_svm.c        | 14 ++++++++++----
 drivers/gpu/drm/xe/xe_vm.h         |  3 +++
 drivers/gpu/drm/xe/xe_vm_madvise.c | 20 +++++++++++++++++++-
 3 files changed, 32 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_svm.c b/drivers/gpu/drm/xe/xe_svm.c
index cb876000411f..ed7f0cfbb546 100644
--- a/drivers/gpu/drm/xe/xe_svm.c
+++ b/drivers/gpu/drm/xe/xe_svm.c
@@ -745,6 +745,12 @@ bool xe_svm_range_needs_migrate_to_vram(struct xe_svm_range *range, struct xe_vm
 	return needs_migrate;
 }
 
+static const u32 region_to_mem_type[] = {
+	XE_PL_TT,
+	XE_PL_VRAM0,
+	XE_PL_VRAM1,
+};
+
 /**
  * xe_svm_handle_pagefault() - SVM handle page fault
  * @vm: The VM.
@@ -796,13 +802,13 @@ int xe_svm_handle_pagefault(struct xe_vm *vm, struct xe_vma *vma,
 
 	range_debug(range, "PAGE FAULT");
 
-	/* for gpu pagefault always migrate to local vram unless
-	 * preferred location provided by madvise
-	 */
-	region = 1;
+	region = vma->attr.preferred_loc.devmem_fd;
 
 	if (xe_svm_range_needs_migrate_to_vram(range, vma, region)) {
 		migrate_try_count--;
+		region = region ? region : 1;
+		/* Need rework for multigpu */
+		tile = &vm->xe->tiles[region_to_mem_type[region] - XE_PL_VRAM0];
 
 		err = xe_svm_alloc_vram(vm, tile, range, &ctx);
 		if (err) {
diff --git a/drivers/gpu/drm/xe/xe_vm.h b/drivers/gpu/drm/xe/xe_vm.h
index 4e45230b7205..377f62f859b7 100644
--- a/drivers/gpu/drm/xe/xe_vm.h
+++ b/drivers/gpu/drm/xe/xe_vm.h
@@ -220,6 +220,9 @@ int __xe_vm_userptr_needs_repin(struct xe_vm *vm);
 
 int xe_vm_userptr_check_repin(struct xe_vm *vm);
 
+bool xe_vma_has_preferred_mem_loc(struct xe_vma *vma,
+				  u32 *mem_region, u32 *devmem_fd);
+
 int xe_vm_rebind(struct xe_vm *vm, bool rebind_worker);
 struct dma_fence *xe_vma_rebind(struct xe_vm *vm, struct xe_vma *vma,
 				u8 tile_mask);
diff --git a/drivers/gpu/drm/xe/xe_vm_madvise.c b/drivers/gpu/drm/xe/xe_vm_madvise.c
index 7e1a95106cb9..f870e8642190 100644
--- a/drivers/gpu/drm/xe/xe_vm_madvise.c
+++ b/drivers/gpu/drm/xe/xe_vm_madvise.c
@@ -61,7 +61,25 @@ static int madvise_preferred_mem_loc(struct xe_device *xe, struct xe_vm *vm,
 				     struct xe_vma **vmas, int num_vmas,
 				     struct drm_xe_madvise_ops ops)
 {
-	/* Implementation pending */
+	s32 devmem_fd;
+	u32 migration_policy;
+	int i;
+
+	xe_assert(vm->xe, ops.type == DRM_XE_VMA_ATTR_PREFERRED_LOC);
+	vm_dbg(&xe->drm, "migration policy = %d, devmem_fd = %d\n",
+	       ops.preferred_mem_loc.migration_policy,
+	       ops.preferred_mem_loc.devmem_fd);
+
+	devmem_fd = (s32)ops.preferred_mem_loc.devmem_fd;
+	devmem_fd = (devmem_fd < 0) ? 0 : devmem_fd;
+
+	migration_policy = ops.preferred_mem_loc.migration_policy;
+
+	for (i = 0; i < num_vmas; i++) {
+		vmas[i]->attr.preferred_loc.devmem_fd = devmem_fd;
+		vmas[i]->attr.preferred_loc.migration_policy = migration_policy;
+	}
+
 	return 0;
 }
 
-- 
2.34.1