drm/i915/uc: Add ops to intel_uc

Instead of spreading multiple conditionals across the uC code
to find out current mode of uC operation, start using predefined
set of function pointers that reflect that mode.

Begin with pair of init_hw/fini_hw functions that are responsible
for uC hardware initialization and cleanup.

v2: drop ops_none, use macro to generate ops helpers
v3: reuse __uc_check_hw to avoid redundant comment
v4: forward declare ops struct vs functions
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20200110222723.14724-2-michal.wajdeczko@intel.com

drivers/gpu/drm/i915/gt/uc/intel_uc.c

@@ -12,6 +12,9 @@
 
 #include "i915_drv.h"
 
+static const struct intel_uc_ops uc_ops_off;
+static const struct intel_uc_ops uc_ops_on;
+
 /* Reset GuC providing us with fresh state for both GuC and HuC.
  */
 static int __intel_uc_reset_hw(struct intel_uc *uc)
@@ -89,6 +92,11 @@ void intel_uc_init_early(struct intel_uc *uc)
 	intel_huc_init_early(&uc->huc);
 
 	__confirm_options(uc);
+
+	if (intel_uc_uses_guc(uc))
+		uc->ops = &uc_ops_on;
+	else
+		uc->ops = &uc_ops_off;
 }
 
 void intel_uc_driver_late_release(struct intel_uc *uc)
@@ -380,13 +388,8 @@ static bool uc_is_wopcm_locked(struct intel_uc *uc)
 	       (intel_uncore_read(uncore, DMA_GUC_WOPCM_OFFSET) & GUC_WOPCM_OFFSET_VALID);
 }
 
-int intel_uc_init_hw(struct intel_uc *uc)
+static int __uc_check_hw(struct intel_uc *uc)
 {
-	struct drm_i915_private *i915 = uc_to_gt(uc)->i915;
-	struct intel_guc *guc = &uc->guc;
-	struct intel_huc *huc = &uc->huc;
-	int ret, attempts;
-
 	if (!intel_uc_supports_guc(uc))
 		return 0;
 
@@ -395,11 +398,24 @@ int intel_uc_init_hw(struct intel_uc *uc)
 	 * before on this system after reboot, otherwise we risk GPU hangs.
 	 * To check if GuC was loaded before we look at WOPCM registers.
 	 */
-	if (!intel_uc_uses_guc(uc) && !uc_is_wopcm_locked(uc))
+	if (uc_is_wopcm_locked(uc))
+		return -EIO;
+
 	return 0;
+}
+
+static int __uc_init_hw(struct intel_uc *uc)
+{
+	struct drm_i915_private *i915 = uc_to_gt(uc)->i915;
+	struct intel_guc *guc = &uc->guc;
+	struct intel_huc *huc = &uc->huc;
+	int ret, attempts;
+
+	GEM_BUG_ON(!intel_uc_supports_guc(uc));
+	GEM_BUG_ON(!intel_uc_uses_guc(uc));
 
 	if (!intel_uc_fw_is_available(&guc->fw)) {
-		ret = uc_is_wopcm_locked(uc) ||
+		ret = __uc_check_hw(uc) ||
 		      intel_uc_fw_is_overridden(&guc->fw) ||
 		      intel_uc_supports_guc_submission(uc) ?
 		      intel_uc_fw_status_to_error(guc->fw.status) : 0;
@@ -495,7 +511,7 @@ int intel_uc_init_hw(struct intel_uc *uc)
 	return -EIO;
 }
 
-void intel_uc_fini_hw(struct intel_uc *uc)
+static void __uc_fini_hw(struct intel_uc *uc)
 {
 	struct intel_guc *guc = &uc->guc;
 
@@ -595,3 +611,12 @@ int intel_uc_runtime_resume(struct intel_uc *uc)
 	 */
 	return __uc_resume(uc, true);
 }
+
+static const struct intel_uc_ops uc_ops_off = {
+	.init_hw = __uc_check_hw,
+};
+
+static const struct intel_uc_ops uc_ops_on = {
+	.init_hw = __uc_init_hw,
+	.fini_hw = __uc_fini_hw,
+};

drivers/gpu/drm/i915/gt/uc/intel_uc.h

@@ -10,7 +10,15 @@
 #include "intel_huc.h"
 #include "i915_params.h"
 
+struct intel_uc;
+
+struct intel_uc_ops {
+	int (*init_hw)(struct intel_uc *uc);
+	void (*fini_hw)(struct intel_uc *uc);
+};
+
 struct intel_uc {
+	struct intel_uc_ops const *ops;
 	struct intel_guc guc;
 	struct intel_huc huc;
 
@@ -25,8 +33,6 @@ void intel_uc_fetch_firmwares(struct intel_uc *uc);
 void intel_uc_cleanup_firmwares(struct intel_uc *uc);
 void intel_uc_sanitize(struct intel_uc *uc);
 void intel_uc_init(struct intel_uc *uc);
-int intel_uc_init_hw(struct intel_uc *uc);
-void intel_uc_fini_hw(struct intel_uc *uc);
 void intel_uc_fini(struct intel_uc *uc);
 void intel_uc_reset_prepare(struct intel_uc *uc);
 void intel_uc_suspend(struct intel_uc *uc);
@@ -64,4 +70,15 @@ static inline bool intel_uc_uses_huc(struct intel_uc *uc)
 	return intel_huc_is_enabled(&uc->huc);
 }
 
+#define intel_uc_ops_function(_NAME, _OPS, _TYPE, _RET) \
+static inline _TYPE intel_uc_##_NAME(struct intel_uc *uc) \
+{ \
+	if (uc->ops->_OPS) \
+		return uc->ops->_OPS(uc); \
+	return _RET; \
+}
+intel_uc_ops_function(init_hw, init_hw, int, 0);
+intel_uc_ops_function(fini_hw, fini_hw, void, );
+#undef intel_uc_ops_function
+
 #endif