drm/i915: Make GuC GGTT reservation work on ggtt

These functions operate on ggtt so make them take that directly as
parameter.

At the same time move the USES_GUC conditional down to
intel_guc_reserve_ggtt_top for symmetry with
intel_guc_reserved_gtt_size.

v2:
 * Rename and move functions to be static in i915_gem_gtt.c (Michal)

v3:
 * Add comment explaining reason for reservation, add assert and fix
   error message. (Michal)

v4:
 * Fix checkpatch error.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
Reviewed-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190611122350.15060-1-tvrtko.ursulin@linux.intel.com

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -2808,6 +2808,32 @@ static void fini_aliasing_ppgtt(struct drm_i915_private *i915)
 	ggtt->vm.vma_ops.unbind_vma = ggtt_unbind_vma;
 }
 
+static int ggtt_reserve_guc_top(struct i915_ggtt *ggtt)
+{
+	u64 size;
+	int ret;
+
+	if (!USES_GUC(ggtt->vm.i915))
+		return 0;
+
+	GEM_BUG_ON(ggtt->vm.total <= GUC_GGTT_TOP);
+	size = ggtt->vm.total - GUC_GGTT_TOP;
+
+	ret = i915_gem_gtt_reserve(&ggtt->vm, &ggtt->uc_fw, size,
+				   GUC_GGTT_TOP, I915_COLOR_UNEVICTABLE,
+				   PIN_NOEVICT);
+	if (ret)
+		DRM_DEBUG_DRIVER("Failed to reserve top of GGTT for GuC\n");
+
+	return ret;
+}
+
+static void ggtt_release_guc_top(struct i915_ggtt *ggtt)
+{
+	if (drm_mm_node_allocated(&ggtt->uc_fw))
+		drm_mm_remove_node(&ggtt->uc_fw);
+}
+
 int i915_gem_init_ggtt(struct drm_i915_private *dev_priv)
 {
 	/* Let GEM Manage all of the aperture.
@@ -2845,11 +2871,14 @@ int i915_gem_init_ggtt(struct drm_i915_private *dev_priv)
 	if (ret)
 		return ret;
 
-	if (USES_GUC(dev_priv)) {
-		ret = intel_guc_reserve_ggtt_top(&dev_priv->guc);
-		if (ret)
-			goto err_reserve;
-	}
+	/*
+	 * The upper portion of the GuC address space has a sizeable hole
+	 * (several MB) that is inaccessible by GuC. Reserve this range within
+	 * GGTT as it can comfortably hold GuC/HuC firmware images.
+	 */
+	ret = ggtt_reserve_guc_top(ggtt);
+	if (ret)
+		goto err_reserve;
 
 	/* Clear any non-preallocated blocks */
 	drm_mm_for_each_hole(entry, &ggtt->vm.mm, hole_start, hole_end) {
@@ -2871,7 +2900,7 @@ int i915_gem_init_ggtt(struct drm_i915_private *dev_priv)
 	return 0;
 
 err_appgtt:
-	intel_guc_release_ggtt_top(&dev_priv->guc);
+	ggtt_release_guc_top(ggtt);
 err_reserve:
 	drm_mm_remove_node(&ggtt->error_capture);
 	return ret;
@@ -2898,7 +2927,7 @@ void i915_ggtt_cleanup_hw(struct drm_i915_private *dev_priv)
 	if (drm_mm_node_allocated(&ggtt->error_capture))
 		drm_mm_remove_node(&ggtt->error_capture);
 
-	intel_guc_release_ggtt_top(&dev_priv->guc);
+	ggtt_release_guc_top(ggtt);
 
 	if (drm_mm_initialized(&ggtt->vm.mm)) {
 		intel_vgt_deballoon(dev_priv);

drivers/gpu/drm/i915/intel_guc.c

@@ -685,30 +685,3 @@ struct i915_vma *intel_guc_allocate_vma(struct intel_guc *guc, u32 size)
 	i915_gem_object_put(obj);
 	return vma;
 }
-
-int intel_guc_reserve_ggtt_top(struct intel_guc *guc)
-{
-	struct drm_i915_private *i915 = guc_to_i915(guc);
-	struct i915_ggtt *ggtt = &i915->ggtt;
-	u64 size;
-	int ret;
-
-	size = ggtt->vm.total - GUC_GGTT_TOP;
-
-	ret = i915_gem_gtt_reserve(&ggtt->vm, &ggtt->uc_fw, size,
-				   GUC_GGTT_TOP, I915_COLOR_UNEVICTABLE,
-				   PIN_NOEVICT);
-	if (ret)
-		DRM_DEBUG_DRIVER("GuC: failed to reserve top of ggtt\n");
-
-	return ret;
-}
-
-void intel_guc_release_ggtt_top(struct intel_guc *guc)
-{
-	struct drm_i915_private *i915 = guc_to_i915(guc);
-	struct i915_ggtt *ggtt = &i915->ggtt;
-
-	if (drm_mm_node_allocated(&ggtt->uc_fw))
-		drm_mm_remove_node(&ggtt->uc_fw);
-}

drivers/gpu/drm/i915/intel_guc.h

@@ -172,8 +172,6 @@ int intel_guc_auth_huc(struct intel_guc *guc, u32 rsa_offset);
 int intel_guc_suspend(struct intel_guc *guc);
 int intel_guc_resume(struct intel_guc *guc);
 struct i915_vma *intel_guc_allocate_vma(struct intel_guc *guc, u32 size);
-int intel_guc_reserve_ggtt_top(struct intel_guc *guc);
-void intel_guc_release_ggtt_top(struct intel_guc *guc);
 
 static inline bool intel_guc_is_loaded(struct intel_guc *guc)
 {