[PATCH 1/3] drm/xe/bo: Forward the decision to evict local objects during validation

[Thomas Hellström]

Currently we refuse evicting the VM's local objects. However that
is necessary for some objects. Most notably completely unbound objects.
Forward this decision to be per-object based in the TTM
eviction_valuable() callback.

Fixes: 24f947d58fe5 ("drm/xe: Use DRM GPUVM helpers for external- and evicted objects")
Cc: Thomas Hellström <thomas.hellstrom at linux.intel.com>
Cc: Rodrigo Vivi <rodrigo.vivi at intel.com>
Cc: Matthew Brost <matthew.brost at intel.com>
Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Cc: Oded Gabbay <ogabbay at kernel.org>
Signed-off-by: Thomas Hellström <thomas.hellstrom at linux.intel.com>
---
 drivers/gpu/drm/xe/xe_bo.c       | 17 ++++++++++++++++-
 drivers/gpu/drm/xe/xe_exec.c     |  2 ++
 drivers/gpu/drm/xe/xe_vm.c       |  8 ++++++--
 drivers/gpu/drm/xe/xe_vm_types.h | 10 ++++++++++
 4 files changed, 34 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_bo.c b/drivers/gpu/drm/xe/xe_bo.c
index 76dfaf1cd200..143d93632253 100644
--- a/drivers/gpu/drm/xe/xe_bo.c
+++ b/drivers/gpu/drm/xe/xe_bo.c
@@ -1049,6 +1049,21 @@ static void xe_ttm_bo_delete_mem_notify(struct ttm_buffer_object *ttm_bo)
 	}
 }
 
+static bool xe_bo_eviction_valuable(struct ttm_buffer_object *ttm_bo,
+				    const struct ttm_place *place)
+{
+	if (xe_bo_is_xe_bo(ttm_bo)) {
+		struct xe_bo *xe_bo = ttm_to_xe_bo(ttm_bo);
+		struct xe_vm *vm = xe_bo->vm;
+
+		if (vm && !drm_gpuvm_is_extobj(&vm->gpuvm, &ttm_bo->base) &&
+		    vm->is_validating)
+			return false;
+	}
+
+	return ttm_bo_eviction_valuable(ttm_bo, place);
+}
+
 const struct ttm_device_funcs xe_ttm_funcs = {
 	.ttm_tt_create = xe_ttm_tt_create,
 	.ttm_tt_populate = xe_ttm_tt_populate,
@@ -1059,7 +1074,7 @@ const struct ttm_device_funcs xe_ttm_funcs = {
 	.io_mem_reserve = xe_ttm_io_mem_reserve,
 	.io_mem_pfn = xe_ttm_io_mem_pfn,
 	.release_notify = xe_ttm_bo_release_notify,
-	.eviction_valuable = ttm_bo_eviction_valuable,
+	.eviction_valuable = xe_bo_eviction_valuable,
 	.delete_mem_notify = xe_ttm_bo_delete_mem_notify,
 };
 
diff --git a/drivers/gpu/drm/xe/xe_exec.c b/drivers/gpu/drm/xe/xe_exec.c
index 952496c6260d..e8eb09993485 100644
--- a/drivers/gpu/drm/xe/xe_exec.c
+++ b/drivers/gpu/drm/xe/xe_exec.c
@@ -102,7 +102,9 @@ static int xe_exec_fn(struct drm_gpuvm_exec *vm_exec)
 	int num_fences;
 	int ret;
 
+	vm->is_validating = true;
 	ret = drm_gpuvm_validate(vm_exec->vm, &vm_exec->exec);
+	vm->is_validating = false;
 	if (ret)
 		return ret;
 
diff --git a/drivers/gpu/drm/xe/xe_vm.c b/drivers/gpu/drm/xe/xe_vm.c
index e3bde897f6e8..07b0cda12d52 100644
--- a/drivers/gpu/drm/xe/xe_vm.c
+++ b/drivers/gpu/drm/xe/xe_vm.c
@@ -474,7 +474,7 @@ static int xe_gpuvm_validate(struct drm_gpuvm_bo *vm_bo, struct drm_exec *exec)
 		list_move_tail(&gpuva_to_vma(gpuva)->combined_links.rebind,
 			       &vm->rebind_list);
 
-	ret = xe_bo_validate(gem_to_xe_bo(vm_bo->obj), vm, false);
+	ret = xe_bo_validate(gem_to_xe_bo(vm_bo->obj), vm, true);
 	if (ret)
 		return ret;
 
@@ -515,7 +515,11 @@ static int xe_preempt_work_begin(struct drm_exec *exec, struct xe_vm *vm,
 	if (err)
 		return err;
 
-	return drm_gpuvm_validate(&vm->gpuvm, exec);
+	vm->is_validating = true;
+	err = drm_gpuvm_validate(&vm->gpuvm, exec);
+	vm->is_validating = false;
+
+	return err;
 }
 
 static void preempt_rebind_work_func(struct work_struct *w)
diff --git a/drivers/gpu/drm/xe/xe_vm_types.h b/drivers/gpu/drm/xe/xe_vm_types.h
index 7d4f810f9c04..76c49fba9cd3 100644
--- a/drivers/gpu/drm/xe/xe_vm_types.h
+++ b/drivers/gpu/drm/xe/xe_vm_types.h
@@ -286,6 +286,16 @@ struct xe_vm {
 
 	/** @batch_invalidate_tlb: Always invalidate TLB before batch start */
 	bool batch_invalidate_tlb;
+
+	/**
+	 * @is_validaing: Whether we are validating the vm's local objects.
+	 * This field is protected by the vm's resv. Note that this
+	 * is needed only since TTM doesn't forward the ttm_operation_ctx to the
+	 * eviction_valuable() callback, so if / when that is in place, this
+	 * should be removed.
+	 */
+	bool is_validating;
+
 	/** @xef: XE file handle for tracking this VM's drm client */
 	struct xe_file *xef;
 };
-- 
2.43.0