[PATCH 2/6] drm/i915/selftests: Confirm that ctx_wa are applied to context saved regs

[Chris Wilson]

The idea behind setting ctx_wa are that they need to be stored in the
context, and to be sure that they will be saved we apply them to a live
context. Any registers not stored in the context should not need to be
applied in this fashion and can use regular mmio.

Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
---
 .../gpu/drm/i915/gt/selftest_workarounds.c    | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/selftest_workarounds.c b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
index ac1921854cbf..336cfd19dd4e 100644
--- a/drivers/gpu/drm/i915/gt/selftest_workarounds.c
+++ b/drivers/gpu/drm/i915/gt/selftest_workarounds.c
@@ -691,6 +691,61 @@ static int check_dirty_whitelist(struct intel_context *ce)
 	return err;
 }
 
+static bool find_register_in_context_image(const u32 *state, u32 offset)
+{
+	int i;
+
+	/* Brute force search of the first page */
+	for (i = 0; i < PAGE_SIZE / sizeof(u32); i++)
+		if (state[i] == offset)
+			return true;
+
+	return false;
+}
+
+static int live_context_whitelist(void *arg)
+{
+	struct intel_gt *gt = arg;
+	struct intel_engine_cs *engine;
+	enum intel_engine_id id;
+	int err = 0;
+
+	for_each_engine(engine, gt, id) {
+		struct i915_wa_list ctx_wa;
+		const void *state;
+		int i;
+
+		if (!engine->default_state)
+			continue;
+
+		__intel_engine_init_ctx_wa(engine, &ctx_wa, "CTX_REF");
+		if (!ctx_wa.count)
+			continue;
+
+		state = i915_gem_object_pin_map(engine->default_state,
+						I915_MAP_WB);
+		if (IS_ERR(state))
+			return PTR_ERR(state);
+
+		if (HAS_EXECLISTS(engine->i915))
+			state += PAGE_SIZE; /* skip ppHWSP */
+
+		for (i = 0; i < ctx_wa.count; i++) {
+			u32 reg = i915_mmio_reg_offset(ctx_wa.list[i].reg);
+
+			if (!find_register_in_context_image(state, reg)) {
+				pr_err("%s ctx_wa reg:%04x is not context saved!\n",
+				       engine->name, reg);
+				err = -EINVAL;
+			}
+		}
+
+		i915_gem_object_unpin_map(engine->default_state);
+	}
+
+	return err;
+}
+
 static int live_dirty_whitelist(void *arg)
 {
 	struct intel_gt *gt = arg;
@@ -1257,6 +1312,7 @@ live_engine_reset_workarounds(void *arg)
 int intel_workarounds_live_selftests(struct drm_i915_private *i915)
 {
 	static const struct i915_subtest tests[] = {
+		SUBTEST(live_context_whitelist),
 		SUBTEST(live_dirty_whitelist),
 		SUBTEST(live_reset_whitelist),
 		SUBTEST(live_isolated_whitelist),
-- 
2.25.0