drm/i915/perf: Validate OA sseu config outside switch

Once OA supports media engine class:instance, the engine can only be
validated outside the switch since class and instance parameters are
separate entities. Since OA sseu config depends on engine
class:instance, validate OA sseu config outside the switch.

v2: (Ashutosh)
- Clarify commit message
- Use drm_dbg instead of DRM_DEBUG
- Reorder stack variables
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230323225901.3743681-4-umesh.nerlige.ramappa@intel.com

drivers/gpu/drm/i915/i915_perf.c

@@ -3940,7 +3940,9 @@ static int read_properties_unlocked(struct i915_perf *perf,
 				    u32 n_props,
 				    struct perf_open_properties *props)
 {
+	struct drm_i915_gem_context_param_sseu user_sseu;
 	u64 __user *uprop = uprops;
+	bool config_sseu = false;
 	u32 i;
 	int ret;
 
@@ -4069,8 +4071,6 @@ static int read_properties_unlocked(struct i915_perf *perf,
 			props->hold_preemption = !!value;
 			break;
 		case DRM_I915_PERF_PROP_GLOBAL_SSEU: {
-			struct drm_i915_gem_context_param_sseu user_sseu;
-
 			if (GRAPHICS_VER_FULL(perf->i915) >= IP_VER(12, 50)) {
 				drm_dbg(&perf->i915->drm,
 					"SSEU config not supported on gfx %x\n",
@@ -4085,14 +4085,7 @@ static int read_properties_unlocked(struct i915_perf *perf,
 					"Unable to copy global sseu parameter\n");
 				return -EFAULT;
 			}
-
-			ret = get_sseu_config(&props->sseu, props->engine, &user_sseu);
-			if (ret) {
-				drm_dbg(&perf->i915->drm,
-					"Invalid SSEU configuration\n");
-				return ret;
-			}
-			props->has_sseu = true;
+			config_sseu = true;
 			break;
 		}
 		case DRM_I915_PERF_PROP_POLL_OA_PERIOD:
@@ -4112,6 +4105,16 @@ static int read_properties_unlocked(struct i915_perf *perf,
 		uprop += 2;
 	}
 
+	if (config_sseu) {
+		ret = get_sseu_config(&props->sseu, props->engine, &user_sseu);
+		if (ret) {
+			drm_dbg(&perf->i915->drm,
+				"Invalid SSEU configuration\n");
+			return ret;
+		}
+		props->has_sseu = true;
+	}
+
 	return 0;
 }