diff --git a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
index c34065fe2ecc..0e57a6d81534 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_stolen.c
@@ -77,22 +77,26 @@ void i915_gem_stolen_remove_node(struct drm_i915_private *i915,
 	mutex_unlock(&i915->mm.stolen_lock);
 }
 
-static int i915_adjust_stolen(struct drm_i915_private *i915,
-			      struct resource *dsm)
+static bool valid_stolen_size(struct resource *dsm)
+{
+	return dsm->start != 0 && dsm->end > dsm->start;
+}
+
+static int adjust_stolen(struct drm_i915_private *i915,
+			 struct resource *dsm)
 {
 	struct i915_ggtt *ggtt = to_gt(i915)->ggtt;
 	struct intel_uncore *uncore = ggtt->vm.gt->uncore;
-	struct resource *r;
 
-	if (dsm->start == 0 || dsm->end <= dsm->start)
+	if (!valid_stolen_size(dsm))
 		return -EINVAL;
 
 	/*
+	 * Make sure we don't clobber the GTT if it's within stolen memory
+	 *
 	 * TODO: We have yet too encounter the case where the GTT wasn't at the
 	 * end of stolen. With that assumption we could simplify this.
 	 */
-
-	/* Make sure we don't clobber the GTT if it's within stolen memory */
 	if (GRAPHICS_VER(i915) <= 4 &&
 	    !IS_G33(i915) && !IS_PINEVIEW(i915) && !IS_G4X(i915)) {
 		struct resource stolen[2] = {*dsm, *dsm};
@@ -131,10 +135,20 @@ static int i915_adjust_stolen(struct drm_i915_private *i915,
 		}
 	}
 
+	if (!valid_stolen_size(dsm))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int request_smem_stolen(struct drm_i915_private *i915,
+			       struct resource *dsm)
+{
+	struct resource *r;
+
 	/*
-	 * With stolen lmem, we don't need to check if the address range
-	 * overlaps with the non-stolen system memory range, since lmem is local
-	 * to the gpu.
+	 * With stolen lmem, we don't need to request if the address range
+	 * since lmem is local to the gpu.
 	 */
 	if (HAS_LMEM(i915))
 		return 0;
@@ -392,39 +406,22 @@ static void icl_get_stolen_reserved(struct drm_i915_private *i915,
 	}
 }
 
-static int i915_gem_init_stolen(struct intel_memory_region *mem)
+/*
+ * Initialize i915->dsm_reserved to contain the reserved space within the Data
+ * Stolen Memory. This is a range on the top of DSM that is reserved, not to
+ * be used by driver, so must be excluded from the region passed to the
+ * allocator later. In the spec this is also called as WOPCM.
+ *
+ * Our expectation is that the reserved space is at the top of the stolen
+ * region, as it has been the case for every platform, and *never* at the
+ * bottom, so the calculation here can be simplified.
+ */
+static int init_reserved_stolen(struct drm_i915_private *i915)
 {
-	struct drm_i915_private *i915 = mem->i915;
 	struct intel_uncore *uncore = &i915->uncore;
 	resource_size_t reserved_base, stolen_top;
-	resource_size_t reserved_total, reserved_size;
-
-	mutex_init(&i915->mm.stolen_lock);
-
-	if (intel_vgpu_active(i915)) {
-		drm_notice(&i915->drm,
-			   "%s, disabling use of stolen memory\n",
-			   "iGVT-g active");
-		return 0;
-	}
-
-	if (i915_vtd_active(i915) && GRAPHICS_VER(i915) < 8) {
-		drm_notice(&i915->drm,
-			   "%s, disabling use of stolen memory\n",
-			   "DMAR active");
-		return 0;
-	}
-
-	if (resource_size(&mem->region) == 0)
-		return 0;
-
-	if (i915_adjust_stolen(i915, &mem->region))
-		return 0;
-
-	GEM_BUG_ON(i915->dsm.start == 0);
-	GEM_BUG_ON(i915->dsm.end <= i915->dsm.start);
-
-	i915->dsm = mem->region;
+	resource_size_t reserved_size;
+	int ret = 0;
 
 	stolen_top = i915->dsm.end + 1;
 	reserved_base = stolen_top;
@@ -453,19 +450,17 @@ static int i915_gem_init_stolen(struct intel_memory_region *mem)
 	} else if (GRAPHICS_VER(i915) >= 5 || IS_G4X(i915)) {
 		g4x_get_stolen_reserved(i915, uncore,
 					&reserved_base, &reserved_size);
+	} else {
+		/* No reserved region */
+		goto bail_out;
 	}
 
-	/*
-	 * Our expectation is that the reserved space is at the top of the
-	 * stolen region and *never* at the bottom. If we see !reserved_base,
-	 * it likely means we failed to read the registers correctly.
-	 */
-	if (!reserved_base) {
+	if (!reserved_base || reserved_base == stolen_top) {
 		drm_err(&i915->drm,
 			"inconsistent reservation %pa + %pa; ignoring\n",
 			&reserved_base, &reserved_size);
-		reserved_base = stolen_top;
-		reserved_size = 0;
+		ret = -EINVAL;
+		goto bail_out;
 	}
 
 	i915->dsm_reserved =
@@ -475,19 +470,55 @@ static int i915_gem_init_stolen(struct intel_memory_region *mem)
 		drm_err(&i915->drm,
 			"Stolen reserved area %pR outside stolen memory %pR\n",
 			&i915->dsm_reserved, &i915->dsm);
+		ret = -EINVAL;
+		goto bail_out;
+	}
+
+	return 0;
+
+bail_out:
+	i915->dsm_reserved =
+		(struct resource)DEFINE_RES_MEM(reserved_base, 0);
+
+	return ret;
+}
+
+static int i915_gem_init_stolen(struct intel_memory_region *mem)
+{
+	struct drm_i915_private *i915 = mem->i915;
+
+	mutex_init(&i915->mm.stolen_lock);
+
+	if (intel_vgpu_active(i915)) {
+		drm_notice(&i915->drm,
+			   "%s, disabling use of stolen memory\n",
+			   "iGVT-g active");
+		return 0;
+	}
+
+	if (i915_vtd_active(i915) && GRAPHICS_VER(i915) < 8) {
+		drm_notice(&i915->drm,
+			   "%s, disabling use of stolen memory\n",
+			   "DMAR active");
 		return 0;
 	}
 
+	if (adjust_stolen(i915, &mem->region))
+		return 0;
+
+	if (request_smem_stolen(i915, &mem->region))
+		return 0;
+
+	i915->dsm = mem->region;
+
+	if (init_reserved_stolen(i915))
+		return 0;
+
 	/* Exclude the reserved region from driver use */
-	mem->region.end = reserved_base - 1;
+	mem->region.end = i915->dsm_reserved.start - 1;
 	mem->io_size = min(mem->io_size, resource_size(&mem->region));
 
-	/* It is possible for the reserved area to end before the end of stolen
-	 * memory, so just consider the start. */
-	reserved_total = stolen_top - reserved_base;
-
-	i915->stolen_usable_size =
-		resource_size(&i915->dsm) - reserved_total;
+	i915->stolen_usable_size = resource_size(&mem->region);
 
 	drm_dbg(&i915->drm,
 		"Memory reserved for graphics device: %lluK, usable: %lluK\n",
@@ -759,11 +790,6 @@ static int init_stolen_lmem(struct intel_memory_region *mem)
 	if (GEM_WARN_ON(resource_size(&mem->region) == 0))
 		return -ENODEV;
 
-	/*
-	 * TODO: For stolen lmem we mostly just care about populating the dsm
-	 * related bits and setting up the drm_mm allocator for the range.
-	 * Perhaps split up i915_gem_init_stolen() for this.
-	 */
 	err = i915_gem_init_stolen(mem);
 	if (err)
 		return err;
