[Intel-gfx] [PATCH i-g-t] tests/kms_pwrite_crc: Add pwrite vs display coherency test

[ville.syrjala at linux.intel.com]

From: Ville Syrjälä <ville.syrjala at linux.intel.com>

Add a test to verify that pwriting to a future scanout buffer works
correctly. The specific problem occurs when the buffer is already
UC/WT before the pwrite, not the current scanout buffer, and not
currently in the CPU write domain. With the buggy kernel no clflush
will be performed after the pwrite, and hence we end up with cache
dirt on the display.

The problem only affects LLC platforms (non-LLC would clflush anywway
after pwrite), but we can let th test run on all platforms.

Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
---
 tests/Makefile.sources |   3 +-
 tests/kms_pwrite_crc.c | 217 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 219 insertions(+), 1 deletion(-)
 create mode 100644 tests/kms_pwrite_crc.c

diff --git a/tests/Makefile.sources b/tests/Makefile.sources
index afbe597..2677bf7 100644
--- a/tests/Makefile.sources
+++ b/tests/Makefile.sources
@@ -145,9 +145,10 @@ TESTS_progs = \
 	gen3_render_tiledy_blits \
 	gen7_forcewake_mt \
 	kms_3d \
+	kms_fence_pin_leak \
 	kms_force_connector \
+	kms_pwrite_crc \
 	kms_sink_crc_basic \
-	kms_fence_pin_leak \
 	prime_udl \
 	$(NULL)
 
diff --git a/tests/kms_pwrite_crc.c b/tests/kms_pwrite_crc.c
new file mode 100644
index 0000000..9c5dabf
--- /dev/null
+++ b/tests/kms_pwrite_crc.c
@@ -0,0 +1,217 @@
+/*
+ * Copyright © 2014 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ *
+ */
+
+#include <errno.h>
+#include <limits.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "drmtest.h"
+#include "igt_debugfs.h"
+#include "igt_kms.h"
+#include "intel_chipset.h"
+#include "ioctl_wrappers.h"
+#include "igt_aux.h"
+
+IGT_TEST_DESCRIPTION(
+   "Use the display CRC support to validate pwrite to an already uncached future scanout buffer.");
+
+typedef struct {
+	int drm_fd;
+	igt_display_t display;
+	struct igt_fb fb[2];
+	igt_output_t *output;
+	igt_plane_t *primary;
+	enum pipe pipe;
+	igt_crc_t ref_crc;
+	igt_pipe_crc_t *pipe_crc;
+	uint32_t devid;
+} data_t;
+
+static void test(data_t *data)
+{
+	igt_display_t *display = &data->display;
+	igt_output_t *output = data->output;
+	struct igt_fb *fb = &data->fb[1];
+	drmModeModeInfo *mode;
+	cairo_t *cr;
+	uint32_t caching;
+	void *buf;
+	igt_crc_t crc;
+
+	mode = igt_output_get_mode(output);
+
+	/* create a non-white fb where we can pwrite later */
+	igt_create_fb(data->drm_fd, mode->hdisplay, mode->vdisplay,
+		      DRM_FORMAT_XRGB8888, I915_TILING_NONE, fb);
+
+	cr = igt_get_cairo_ctx(data->drm_fd, fb);
+	igt_paint_test_pattern(cr, fb->width, fb->height);
+	cairo_destroy(cr);
+
+	/* flip to it to make it UC/WC and fully flushed */
+	igt_plane_set_fb(data->primary, fb);
+	igt_display_commit(display);
+
+	/* sanity check to make sure crc changed */
+	igt_pipe_crc_collect_crc(data->pipe_crc, &crc);
+	igt_assert(!igt_crc_equal(&crc, &data->ref_crc));
+
+	/* flip back the original white buffer */
+	igt_plane_set_fb(data->primary, &data->fb[0]);
+	igt_display_commit(display);
+
+	/* make sure caching mode has become UC/WT */
+	caching = gem_get_caching(data->drm_fd, fb->gem_handle);
+	igt_assert(caching == I915_CACHING_NONE || caching == I915_CACHING_DISPLAY);
+
+	/* use pwrite to make the other fb all white too */
+	buf = malloc(fb->size);
+	igt_assert(buf != NULL);
+	memset(buf, 0xff, fb->size);
+	gem_write(data->drm_fd, fb->gem_handle, 0, buf, fb->size);
+	free(buf);
+
+	/* and flip to it */
+	igt_plane_set_fb(data->primary, fb);
+	igt_display_commit(display);
+
+	/* check that the crc is as expected, which requires that caches got flushed */
+	igt_pipe_crc_collect_crc(data->pipe_crc, &crc);
+	igt_assert(igt_crc_equal(&crc, &data->ref_crc));
+}
+
+static bool prepare_crtc(data_t *data)
+{
+	igt_display_t *display = &data->display;
+	igt_output_t *output = data->output;
+	drmModeModeInfo *mode;
+
+	/* select the pipe we want to use */
+	igt_output_set_pipe(output, data->pipe);
+	igt_display_commit(display);
+
+	if (!output->valid) {
+		igt_output_set_pipe(output, PIPE_ANY);
+		igt_display_commit(display);
+		return false;
+	}
+
+	mode = igt_output_get_mode(output);
+
+	/* create a white reference fb and flip to it */
+	igt_create_color_fb(data->drm_fd, mode->hdisplay, mode->vdisplay,
+			    DRM_FORMAT_XRGB8888, I915_TILING_NONE,
+			    1.0, 1.0, 1.0, &data->fb[0]);
+
+	data->primary = igt_output_get_plane(output, IGT_PLANE_PRIMARY);
+
+	igt_plane_set_fb(data->primary, &data->fb[0]);
+	igt_display_commit(display);
+
+	if (data->pipe_crc)
+		igt_pipe_crc_free(data->pipe_crc);
+
+	data->pipe_crc = igt_pipe_crc_new(data->pipe,
+					  INTEL_PIPE_CRC_SOURCE_AUTO);
+	if (!data->pipe_crc) {
+		igt_info("auto crc not supported on this connector with pipe %i\n",
+			 data->pipe);
+		return false;
+	}
+
+	/* get reference crc for the white fb */
+	igt_pipe_crc_collect_crc(data->pipe_crc, &data->ref_crc);
+
+	return true;
+}
+
+static void cleanup_crtc(data_t *data)
+{
+	igt_display_t *display = &data->display;
+	igt_output_t *output = data->output;
+
+	igt_pipe_crc_free(data->pipe_crc);
+	data->pipe_crc = NULL;
+
+	igt_plane_set_fb(data->primary, NULL);
+
+	igt_output_set_pipe(output, PIPE_ANY);
+	igt_display_commit(display);
+
+	igt_remove_fb(data->drm_fd, &data->fb[0]);
+	igt_remove_fb(data->drm_fd, &data->fb[1]);
+
+}
+
+static void run_test(data_t *data)
+{
+	igt_display_t *display = &data->display;
+	igt_output_t *output;
+	enum pipe pipe;
+
+	for_each_connected_output(display, output) {
+		data->output = output;
+		for_each_pipe(display, pipe) {
+			data->pipe = pipe;
+
+			if (!prepare_crtc(data))
+				continue;
+
+			test(data);
+			cleanup_crtc(data);
+
+			/* once is enough */
+			return;
+		}
+	}
+
+	igt_skip("no valid crtc/connector combinations found\n");
+}
+
+static data_t data;
+
+igt_simple_main
+{
+	igt_skip_on_simulation();
+
+	igt_fixture {
+		data.drm_fd = drm_open_any_master();
+
+		data.devid = intel_get_drm_devid(data.drm_fd);
+
+		kmstest_set_vt_graphics_mode();
+
+		igt_require_pipe_crc();
+
+		igt_display_init(&data.display, data.drm_fd);
+	}
+
+	run_test(&data);
+
+	igt_fixture {
+		igt_display_fini(&data.display);
+	}
+}
-- 
2.0.4