drm/i915: Refactor confusing __intel_gt_reset()

__intel_gt_reset() is really for resetting engines though
the name might suggest something else. So add a helper function
to remove confusions with no functional changes.

v2: Move intel_gt_reset_all_engines() next to
    intel_gt_reset_engine() to make diff simple(John)

Cc: John Harrison <john.c.harrison@intel.com>
Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
Reviewed-by: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240422201951.633-1-nirmoy.das@intel.com

drivers/gpu/drm/i915/gt/intel_engine_cs.c

@@ -679,7 +679,7 @@ void intel_engines_release(struct intel_gt *gt)
 	 */
 	GEM_BUG_ON(intel_gt_pm_is_awake(gt));
 	if (!INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
-		__intel_gt_reset(gt, ALL_ENGINES);
+		intel_gt_reset_all_engines(gt);
 
 	/* Decouple the backend; but keep the layout for late GPU resets */
 	for_each_engine(engine, gt, id) {

drivers/gpu/drm/i915/gt/intel_execlists_submission.c

@@ -2898,7 +2898,7 @@ static void enable_error_interrupt(struct intel_engine_cs *engine)
 		drm_err(&engine->i915->drm,
 			"engine '%s' resumed still in error: %08x\n",
 			engine->name, status);
-		__intel_gt_reset(engine->gt, engine->mask);
+		intel_gt_reset_engine(engine);
 	}
 
 	/*

drivers/gpu/drm/i915/gt/intel_gt.c

@@ -832,7 +832,7 @@ void intel_gt_driver_unregister(struct intel_gt *gt)
 
 	/* Scrub all HW state upon release */
 	with_intel_runtime_pm(gt->uncore->rpm, wakeref)
-		__intel_gt_reset(gt, ALL_ENGINES);
+		intel_gt_reset_all_engines(gt);
 }
 
 void intel_gt_driver_release(struct intel_gt *gt)

drivers/gpu/drm/i915/gt/intel_gt_pm.c

@@ -159,7 +159,7 @@ static bool reset_engines(struct intel_gt *gt)
 	if (INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
 		return false;
 
-	return __intel_gt_reset(gt, ALL_ENGINES) == 0;
+	return intel_gt_reset_all_engines(gt) == 0;
 }
 
 static void gt_sanitize(struct intel_gt *gt, bool force)

drivers/gpu/drm/i915/gt/intel_reset.c

@@ -764,7 +764,7 @@ wa_14015076503_end(struct intel_gt *gt, intel_engine_mask_t engine_mask)
 			 HECI_H_GS1_ER_PREP, 0);
 }
 
-int __intel_gt_reset(struct intel_gt *gt, intel_engine_mask_t engine_mask)
+static int __intel_gt_reset(struct intel_gt *gt, intel_engine_mask_t engine_mask)
 {
 	const int retries = engine_mask == ALL_ENGINES ? RESET_MAX_RETRIES : 1;
 	reset_func reset;
@@ -978,7 +978,7 @@ static void __intel_gt_set_wedged(struct intel_gt *gt)
 
 	/* Even if the GPU reset fails, it should still stop the engines */
 	if (!INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
-		__intel_gt_reset(gt, ALL_ENGINES);
+		intel_gt_reset_all_engines(gt);
 
 	for_each_engine(engine, gt, id)
 		engine->submit_request = nop_submit_request;
@@ -1088,7 +1088,7 @@ static bool __intel_gt_unset_wedged(struct intel_gt *gt)
 	/* We must reset pending GPU events before restoring our submission */
 	ok = !HAS_EXECLISTS(gt->i915); /* XXX better agnosticism desired */
 	if (!INTEL_INFO(gt->i915)->gpu_reset_clobbers_display)
-		ok = __intel_gt_reset(gt, ALL_ENGINES) == 0;
+		ok = intel_gt_reset_all_engines(gt) == 0;
 	if (!ok) {
 		/*
 		 * Warn CI about the unrecoverable wedged condition.
@@ -1132,10 +1132,10 @@ static int do_reset(struct intel_gt *gt, intel_engine_mask_t stalled_mask)
 {
 	int err, i;
 
-	err = __intel_gt_reset(gt, ALL_ENGINES);
+	err = intel_gt_reset_all_engines(gt);
 	for (i = 0; err && i < RESET_MAX_RETRIES; i++) {
 		msleep(10 * (i + 1));
-		err = __intel_gt_reset(gt, ALL_ENGINES);
+		err = intel_gt_reset_all_engines(gt);
 	}
 	if (err)
 		return err;
@@ -1269,7 +1269,30 @@ void intel_gt_reset(struct intel_gt *gt,
 	goto finish;
 }
 
-static int intel_gt_reset_engine(struct intel_engine_cs *engine)
+/**
+ * intel_gt_reset_all_engines() - Reset all engines in the given gt.
+ * @gt: the GT to reset all engines for.
+ *
+ * This function resets all engines within the given gt.
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int intel_gt_reset_all_engines(struct intel_gt *gt)
+{
+	return __intel_gt_reset(gt, ALL_ENGINES);
+}
+
+/**
+ * intel_gt_reset_engine() - Reset a specific engine within a gt.
+ * @engine: engine to be reset.
+ *
+ * This function resets the specified engine within a gt.
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+int intel_gt_reset_engine(struct intel_engine_cs *engine)
 {
 	return __intel_gt_reset(engine->gt, engine->mask);
 }

drivers/gpu/drm/i915/gt/intel_reset.h

@@ -54,7 +54,8 @@ int intel_gt_terminally_wedged(struct intel_gt *gt);
 void intel_gt_set_wedged_on_init(struct intel_gt *gt);
 void intel_gt_set_wedged_on_fini(struct intel_gt *gt);
 
-int __intel_gt_reset(struct intel_gt *gt, intel_engine_mask_t engine_mask);
+int intel_gt_reset_engine(struct intel_engine_cs *engine);
+int intel_gt_reset_all_engines(struct intel_gt *gt);
 
 int intel_reset_guc(struct intel_gt *gt);
 

drivers/gpu/drm/i915/gt/selftest_reset.c

@@ -281,7 +281,7 @@ static int igt_atomic_reset(void *arg)
 		awake = reset_prepare(gt);
 		p->critical_section_begin();
 
-		err = __intel_gt_reset(gt, ALL_ENGINES);
+		err = intel_gt_reset_all_engines(gt);
 
 		p->critical_section_end();
 		reset_finish(gt, awake);

drivers/gpu/drm/i915/i915_driver.c

@@ -202,7 +202,7 @@ static void sanitize_gpu(struct drm_i915_private *i915)
 		unsigned int i;
 
 		for_each_gt(gt, i915, i)
-			__intel_gt_reset(gt, ALL_ENGINES);
+			intel_gt_reset_all_engines(gt);
 	}
 }