[Intel-gfx] [PATCH] drm/i915/selftests: Refactor sibling selection

[Chris Wilson]

Tvrtko spotted that some selftests were using 'break' not 'continue',
which will fail for discontiguous engine layouts such as on Icelake
(which may have vcs0 and vcs2).

Reported-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 drivers/gpu/drm/i915/gt/selftest_lrc.c | 68 ++++++++++----------------
 1 file changed, 27 insertions(+), 41 deletions(-)

diff --git a/drivers/gpu/drm/i915/gt/selftest_lrc.c b/drivers/gpu/drm/i915/gt/selftest_lrc.c
index 824f99c4cc7c..94854a467e66 100644
--- a/drivers/gpu/drm/i915/gt/selftest_lrc.c
+++ b/drivers/gpu/drm/i915/gt/selftest_lrc.c
@@ -3600,13 +3600,30 @@ static int nop_virtual_engine(struct intel_gt *gt,
 	return err;
 }
 
+static unsigned int select_siblings(struct intel_gt *gt,
+				    unsigned int class,
+				    struct intel_engine_cs **siblings)
+{
+	unsigned int n = 0;
+	unsigned int inst;
+
+	for (inst = 0; inst <= MAX_ENGINE_INSTANCE; inst++) {
+		if (!gt->engine_class[class][inst])
+			continue;
+
+		siblings[n++] = gt->engine_class[class][inst];
+	}
+
+	return n;
+}
+
 static int live_virtual_engine(void *arg)
 {
 	struct intel_gt *gt = arg;
 	struct intel_engine_cs *siblings[MAX_ENGINE_INSTANCE + 1];
 	struct intel_engine_cs *engine;
 	enum intel_engine_id id;
-	unsigned int class, inst;
+	unsigned int class;
 	int err;
 
 	if (intel_uc_uses_guc_submission(&gt->uc))
@@ -3624,13 +3641,7 @@ static int live_virtual_engine(void *arg)
 	for (class = 0; class <= MAX_ENGINE_CLASS; class++) {
 		int nsibling, n;
 
-		nsibling = 0;
-		for (inst = 0; inst <= MAX_ENGINE_INSTANCE; inst++) {
-			if (!gt->engine_class[class][inst])
-				continue;
-
-			siblings[nsibling++] = gt->engine_class[class][inst];
-		}
+		nsibling = select_siblings(gt, class, siblings);
 		if (nsibling < 2)
 			continue;
 
@@ -3739,7 +3750,7 @@ static int live_virtual_mask(void *arg)
 {
 	struct intel_gt *gt = arg;
 	struct intel_engine_cs *siblings[MAX_ENGINE_INSTANCE + 1];
-	unsigned int class, inst;
+	unsigned int class;
 	int err;
 
 	if (intel_uc_uses_guc_submission(&gt->uc))
@@ -3748,13 +3759,7 @@ static int live_virtual_mask(void *arg)
 	for (class = 0; class <= MAX_ENGINE_CLASS; class++) {
 		unsigned int nsibling;
 
-		nsibling = 0;
-		for (inst = 0; inst <= MAX_ENGINE_INSTANCE; inst++) {
-			if (!gt->engine_class[class][inst])
-				break;
-
-			siblings[nsibling++] = gt->engine_class[class][inst];
-		}
+		nsibling = select_siblings(gt, class, siblings);
 		if (nsibling < 2)
 			continue;
 
@@ -3876,7 +3881,7 @@ static int live_virtual_preserved(void *arg)
 {
 	struct intel_gt *gt = arg;
 	struct intel_engine_cs *siblings[MAX_ENGINE_INSTANCE + 1];
-	unsigned int class, inst;
+	unsigned int class;
 
 	/*
 	 * Check that the context image retains non-privileged (user) registers
@@ -3894,13 +3899,7 @@ static int live_virtual_preserved(void *arg)
 	for (class = 0; class <= MAX_ENGINE_CLASS; class++) {
 		int nsibling, err;
 
-		nsibling = 0;
-		for (inst = 0; inst <= MAX_ENGINE_INSTANCE; inst++) {
-			if (!gt->engine_class[class][inst])
-				continue;
-
-			siblings[nsibling++] = gt->engine_class[class][inst];
-		}
+		nsibling = select_siblings(gt, class, siblings);
 		if (nsibling < 2)
 			continue;
 
@@ -4111,7 +4110,7 @@ static int live_virtual_bond(void *arg)
 	};
 	struct intel_gt *gt = arg;
 	struct intel_engine_cs *siblings[MAX_ENGINE_INSTANCE + 1];
-	unsigned int class, inst;
+	unsigned int class;
 	int err;
 
 	if (intel_uc_uses_guc_submission(&gt->uc))
@@ -4121,14 +4120,7 @@ static int live_virtual_bond(void *arg)
 		const struct phase *p;
 		int nsibling;
 
-		nsibling = 0;
-		for (inst = 0; inst <= MAX_ENGINE_INSTANCE; inst++) {
-			if (!gt->engine_class[class][inst])
-				break;
-
-			GEM_BUG_ON(nsibling == ARRAY_SIZE(siblings));
-			siblings[nsibling++] = gt->engine_class[class][inst];
-		}
+		nsibling = select_siblings(gt, class, siblings);
 		if (nsibling < 2)
 			continue;
 
@@ -4266,7 +4258,7 @@ static int live_virtual_reset(void *arg)
 {
 	struct intel_gt *gt = arg;
 	struct intel_engine_cs *siblings[MAX_ENGINE_INSTANCE + 1];
-	unsigned int class, inst;
+	unsigned int class;
 
 	/*
 	 * Check that we handle a reset event within a virtual engine.
@@ -4284,13 +4276,7 @@ static int live_virtual_reset(void *arg)
 	for (class = 0; class <= MAX_ENGINE_CLASS; class++) {
 		int nsibling, err;
 
-		nsibling = 0;
-		for (inst = 0; inst <= MAX_ENGINE_INSTANCE; inst++) {
-			if (!gt->engine_class[class][inst])
-				continue;
-
-			siblings[nsibling++] = gt->engine_class[class][inst];
-		}
+		nsibling = select_siblings(gt, class, siblings);
 		if (nsibling < 2)
 			continue;
 
-- 
2.20.1