[PATCH igt] tests/kms_mmio_vs_cs_flip: Add a test case to exercise mmio vs. CS flip races

[ville.syrjala@linux.intel.com]

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

kms_mmio_vs_cs_flip has two subtests:
- setplane_vs_cs_flip tests the interaction between
  fullscreen sprites and CS flips
- setcrtc_vs_cs_flip tests the interaction between
  primary plane panning and CS flips

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
---
 tests/Makefile.sources      |   1 +
 tests/kms_mmio_vs_cs_flip.c | 519 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 520 insertions(+)
 create mode 100644 tests/kms_mmio_vs_cs_flip.c

diff --git a/tests/Makefile.sources b/tests/Makefile.sources
index c957ace..6ff0a35 100644
--- a/tests/Makefile.sources
+++ b/tests/Makefile.sources
@@ -60,6 +60,7 @@ TESTS_progs_M = \
 	kms_fbc_crc \
 	kms_flip \
 	kms_flip_tiling \
+	kms_mmio_vs_cs_flip \
 	kms_pipe_crc_basic \
 	kms_plane \
 	kms_render \
diff --git a/tests/kms_mmio_vs_cs_flip.c b/tests/kms_mmio_vs_cs_flip.c
new file mode 100644
index 0000000..9d9b02a
--- /dev/null
+++ b/tests/kms_mmio_vs_cs_flip.c
@@ -0,0 +1,519 @@
+/*
+ * 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 <stdbool.h>
+#include <stdio.h>
+#include <string.h>
+#include <time.h>
+
+#include "drmtest.h"
+#include "igt_debugfs.h"
+#include "igt_kms.h"
+#include "intel_chipset.h"
+#include "ioctl_wrappers.h"
+
+typedef struct {
+	int drm_fd;
+	igt_display_t display;
+	igt_pipe_crc_t *pipe_crc;
+	drm_intel_bufmgr *bufmgr;
+	drm_intel_bo *busy_bo;
+	uint32_t devid;
+	bool flip_done;
+} data_t;
+
+static void exec_nop(data_t *data, uint32_t handle, unsigned int ring)
+{
+	struct intel_batchbuffer *batch;
+	drm_intel_bo *bo;
+
+	batch = intel_batchbuffer_alloc(data->bufmgr, data->devid);
+	igt_assert(batch);
+
+	bo = gem_handle_to_libdrm_bo(data->bufmgr, data->drm_fd, "", handle);
+	igt_assert(bo);
+
+	/* add relocs to make sure the kernel will think we write to dst */
+	BEGIN_BATCH(4);
+	OUT_BATCH(MI_BATCH_BUFFER_END);
+	OUT_BATCH(MI_NOOP);
+	OUT_RELOC(bo, I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER, 0);
+	OUT_BATCH(MI_NOOP);
+	ADVANCE_BATCH();
+
+	intel_batchbuffer_flush_on_ring(batch, ring);
+	intel_batchbuffer_free(batch);
+}
+
+static void exec_blt(data_t *data)
+{
+	struct intel_batchbuffer *batch;
+	int w, h, pitch, i;
+
+	batch = intel_batchbuffer_alloc(data->bufmgr, data->devid);
+	igt_assert(batch);
+
+	w = 8192;
+	h = data->busy_bo->size / (8192 * 4);
+	pitch = w * 4;
+
+	for (i = 0; i < 20; i++) {
+		BLIT_COPY_BATCH_START(data->devid, 0);
+		OUT_BATCH((3 << 24) | /* 32 bits */
+			  (0xcc << 16) | /* copy ROP */
+			  pitch);
+		OUT_BATCH(0 << 16 | 0);
+		OUT_BATCH(h << 16 | w);
+		OUT_RELOC(data->busy_bo, I915_GEM_DOMAIN_RENDER, I915_GEM_DOMAIN_RENDER, 0);
+		BLIT_RELOC_UDW(data->devid);
+		OUT_BATCH(0 << 16 | 0);
+		OUT_BATCH(pitch);
+		OUT_RELOC(data->busy_bo, I915_GEM_DOMAIN_RENDER, 0, 0);
+		BLIT_RELOC_UDW(data->devid);
+		ADVANCE_BATCH();
+	}
+
+	intel_batchbuffer_flush(batch);
+	intel_batchbuffer_free(batch);
+}
+
+static void page_flip_handler(int fd, unsigned int frame, unsigned int sec,
+			      unsigned int usec, void *_data)
+{
+	data_t *data = _data;
+
+	data->flip_done = true;
+}
+
+static void wait_for_flip(data_t *data, uint32_t flip_handle)
+{
+	struct timeval timeout = {
+		.tv_sec = 3,
+		.tv_usec = 0,
+	};
+	drmEventContext evctx = {
+		.version = DRM_EVENT_CONTEXT_VERSION,
+		.page_flip_handler = page_flip_handler,
+	};
+	fd_set fds;
+
+	FD_ZERO(&fds);
+	FD_SET(data->drm_fd, &fds);
+
+	while (!data->flip_done) {
+		int ret = select(data->drm_fd + 1, &fds, NULL, NULL, &timeout);
+
+		if (ret < 0 && errno == EINTR)
+			continue;
+
+		igt_assert(ret >= 0);
+
+		do_or_die(drmHandleEvent(data->drm_fd, &evctx));
+	}
+
+	/*
+	 * The flip completion may have been signalled prematurely, so
+	 * also submit another nop batch and wait for it to make sure
+	 * the ring has really been drained.
+	 */
+	if (IS_GEN7(data->devid) || IS_GEN8(data->devid))
+		exec_nop(data, flip_handle, I915_EXEC_BLT);
+	else
+		exec_nop(data, flip_handle, I915_EXEC_RENDER);
+	gem_sync(data->drm_fd, flip_handle);
+}
+
+static void make_gpu_busy(data_t *data, uint32_t flip_handle)
+{
+	/*
+	 * Make sure flip_handle has been used on the blt ring.
+	 * This should make the flip use the same ring on gen7+.
+	 */
+	if (IS_GEN7(data->devid) || IS_GEN8(data->devid))
+		exec_nop(data, flip_handle, I915_EXEC_BLT);
+
+	/*
+	 * Add a pile commands to the ring.  The flip will be
+	 * stuck behing these commands and hence gets delayed
+	 * significantly.
+	 */
+	exec_blt(data);
+
+	/*
+	 * Make sure the render ring will block until the blt ring is clear.
+	 * This is in case the flip will execute on the render ring and the
+	 * blits were on the blt ring (this will be the case on gen6 at least).
+	 *
+	 * We can't add an explicit dependency between flip_handle and the
+	 * blits since that would cause the driver to block until the blits
+	 * have completed before it will perform a subsequent mmio flip,
+	 * and so the test would fail to exercise the mmio vs. CS flip race.
+	 */
+	if (HAS_BLT_RING(data->devid))
+		exec_nop(data, data->busy_bo->handle, I915_EXEC_RENDER);
+}
+
+/*
+ * 1. set primary plane to full red
+ * 2. grab a reference crc
+ * 3. set primary plane to full blue
+ * 4. queue lots of GPU activity to delay the subsequent page flip
+ * 5. queue a page flip to the same blue fb
+ * 6. toggle a fullscreen sprite (green) on and back off again
+ * 7. set primary plane to red fb
+ * 8. wait for GPU to finish
+ * 9. compare current crc with reference crc
+ *
+ * We expect the primary plane to display full red at the end.
+ * If the sprite operations have interfered with the page flip,
+ * the driver may have mistakenly completed the flip before
+ * it was executed by the CS, and hence the subsequent mmio
+ * flips may have overtaken it. So once we've finished everything
+ * the CS flip may have been the last thing to occur, which means
+ * the primary plane may be full blue instead of the red it's
+ * supposed to be.
+ */
+static void
+test_plane(data_t *data, igt_output_t *output, enum pipe pipe, enum igt_plane plane)
+{
+	struct igt_fb red_fb, green_fb, blue_fb;
+	drmModeModeInfo *mode;
+	igt_plane_t *primary, *sprite;
+	igt_crc_t ref_crc, crc;
+	int ret;
+
+	if (data->pipe_crc)
+		igt_pipe_crc_free(data->pipe_crc);
+	data->pipe_crc = igt_pipe_crc_new(pipe, INTEL_PIPE_CRC_SOURCE_AUTO);
+
+	igt_output_set_pipe(output, pipe);
+	primary = igt_output_get_plane(output, 0);
+	sprite = igt_output_get_plane(output, plane);
+	igt_display_commit(&data->display);
+
+	mode = igt_output_get_mode(output);
+	igt_create_color_fb(data->drm_fd, mode->hdisplay, mode->vdisplay,
+			    DRM_FORMAT_XRGB8888,
+			    false, /* tiled */
+			    1.0, 0.0, 0.0,
+			    &red_fb);
+	igt_create_color_fb(data->drm_fd, mode->hdisplay, mode->vdisplay,
+			    DRM_FORMAT_XRGB8888,
+			    false, /* tiled */
+			    0.0, 1.0, 0.0,
+			    &green_fb);
+	igt_create_color_fb(data->drm_fd, mode->hdisplay, mode->vdisplay,
+			    DRM_FORMAT_XRGB8888,
+			    false, /* tiled */
+			    0.0, 0.0, 1.0,
+			    &blue_fb);
+
+	/*
+	 * Make sure these buffers are suited for display use
+	 * because most of the modeset operations must be fast
+	 * later on.
+	 */
+	igt_plane_set_fb(primary, &blue_fb);
+	igt_display_commit(&data->display);
+	igt_plane_set_fb(sprite, &green_fb);
+	igt_display_commit(&data->display);
+	igt_plane_set_fb(sprite, NULL);
+	igt_display_commit(&data->display);
+
+	/* set red fb and grab reference crc */
+	igt_plane_set_fb(primary, &red_fb);
+	igt_display_commit(&data->display);
+	igt_pipe_crc_collect_crc(data->pipe_crc, &ref_crc);
+
+	ret = drmModeSetCrtc(data->drm_fd, output->config.crtc->crtc_id,
+			     blue_fb.fb_id, 0, 0, &output->id, 1,
+			     mode);
+	igt_assert(ret == 0);
+
+	make_gpu_busy(data, blue_fb.gem_handle);
+
+	data->flip_done = false;
+	ret = drmModePageFlip(data->drm_fd, output->config.crtc->crtc_id,
+			      blue_fb.fb_id, DRM_MODE_PAGE_FLIP_EVENT, data);
+	igt_assert(ret == 0);
+
+	/*
+	 * Toggle a fullscreen sprite on and back off. This will result
+	 * in the primary plane getting disabled and re-enbled, and that
+	 * leads to mmio flips. The driver may then mistake the flip done
+	 * interrupts from the mmio flips as the flip done interrupts for
+	 * the CS flip, and hence subsequent mmio flips won't wait for the
+	 * CS flips like they should.
+	 */
+	ret = drmModeSetPlane(data->drm_fd,
+			      sprite->drm_plane->plane_id,
+			      output->config.crtc->crtc_id,
+			      green_fb.fb_id, 0,
+			      0, 0, mode->hdisplay, mode->vdisplay,
+			      0, 0, mode->hdisplay << 16, mode->vdisplay << 16);
+	igt_assert(ret == 0);
+	ret = drmModeSetPlane(data->drm_fd,
+			      sprite->drm_plane->plane_id,
+			      output->config.crtc->crtc_id,
+			      0, 0,
+			      0, 0, 0, 0,
+			      0, 0, 0, 0);
+	igt_assert(ret == 0);
+
+	/*
+	 * Set primary plane to red fb. This should wait for the CS flip
+	 * to complete. But if the kernel mistook the flip done interrupt
+	 * from the mmio flip as the flip done from the CS flip, this will
+	 * not wait for anything. And hence the the CS flip will actually
+	 * occur after this mmio flip.
+	 */
+	ret = drmModeSetCrtc(data->drm_fd, output->config.crtc->crtc_id,
+			     red_fb.fb_id, 0, 0, &output->id, 1,
+			     mode);
+	igt_assert(ret == 0);
+
+	/* Make sure the flip has been executed */
+	wait_for_flip(data, blue_fb.gem_handle);
+
+	/* Grab crc and compare with the extected result */
+	igt_pipe_crc_collect_crc(data->pipe_crc, &crc);
+
+	igt_plane_set_fb(primary, NULL);
+	igt_display_commit(&data->display);
+
+	igt_remove_fb(data->drm_fd, &red_fb);
+	igt_remove_fb(data->drm_fd, &green_fb);
+	igt_remove_fb(data->drm_fd, &blue_fb);
+
+	igt_pipe_crc_free(data->pipe_crc);
+	data->pipe_crc = NULL;
+
+	igt_output_set_pipe(output, PIPE_ANY);
+	igt_display_commit(&data->display);
+
+	igt_assert(igt_crc_equal(&ref_crc, &crc));
+}
+
+/*
+ * 1. set primary plane to full red
+ * 2. grab a reference crc
+ * 3. set primary plane to full green
+ * 4. wait for vblank
+ * 5. pan primary plane a bit (to cause a mmio flip w/o vblank wait)
+ * 6. queue lots of GPU activity to delay the subsequent page flip
+ * 6. queue a page flip to a blue fb
+ * 7. set primary plane to red fb
+ * 8. wait for GPU to finish
+ * 9. compare current crc with reference crc
+ *
+ * We expect the primary plane to display full red at the end.
+ * If the previously schedule primary plane pan operation has interfered
+ * with the following page flip, the driver may have mistakenly completed
+ * the flip before it was executed by the CS, and hence the subsequent mmio
+ * flips may have overtaken it. So once we've finished everything
+ * the CS flip may have been the last thing to occur, which means
+ * the primary plane may be full blue instead of the red it's
+ * supposed to be.
+ */
+static void
+test_crtc(data_t *data, igt_output_t *output, enum pipe pipe)
+{
+	struct igt_fb red_fb, green_fb, blue_fb;
+	drmModeModeInfo *mode;
+	igt_plane_t *primary;
+	igt_crc_t ref_crc, crc;
+	int ret;
+
+	if (data->pipe_crc)
+		igt_pipe_crc_free(data->pipe_crc);
+	data->pipe_crc = igt_pipe_crc_new(pipe, INTEL_PIPE_CRC_SOURCE_AUTO);
+
+	igt_output_set_pipe(output, pipe);
+	primary = igt_output_get_plane(output, 0);
+
+	mode = igt_output_get_mode(output);
+	igt_create_color_fb(data->drm_fd, mode->hdisplay, mode->vdisplay+1,
+			    DRM_FORMAT_XRGB8888,
+			    false, /* tiled */
+			    1.0, 0.0, 0.0,
+			    &red_fb);
+	igt_create_color_fb(data->drm_fd, mode->hdisplay, mode->vdisplay+1,
+			    DRM_FORMAT_XRGB8888,
+			    false, /* tiled */
+			    0.0, 0.0, 1.0,
+			    &blue_fb);
+	igt_create_color_fb(data->drm_fd, mode->hdisplay, mode->vdisplay+1,
+			    DRM_FORMAT_XRGB8888,
+			    false, /* tiled */
+			    0.0, 1.0, 0.0,
+			    &green_fb);
+
+	/*
+	 * Make sure these buffers are suited for display use
+	 * because most of the modeset operations must be fast
+	 * later on.
+	 */
+	igt_plane_set_fb(primary, &green_fb);
+	igt_display_commit(&data->display);
+	igt_plane_set_fb(primary, &blue_fb);
+	igt_display_commit(&data->display);
+
+	/* set red fb and grab reference crc */
+	igt_plane_set_fb(primary, &red_fb);
+	igt_display_commit(&data->display);
+	igt_pipe_crc_collect_crc(data->pipe_crc, &ref_crc);
+
+	/*
+	 * Further down we need to issue an mmio flip w/o the kernel
+	 * waiting for vblank. The easiest way is to just pan within
+	 * the same FB. So pan away a bit here, and later we undo this
+	 * with another pan which will result in the desired mmio flip.
+	 */
+	ret = drmModeSetCrtc(data->drm_fd, output->config.crtc->crtc_id,
+			     green_fb.fb_id, 0, 1, &output->id, 1,
+			     mode);
+	igt_assert(ret == 0);
+
+	/*
+	 * Make it more likely that the CS flip has been submitted into the
+	 * ring by the time the mmio flip from the drmModeSetCrtc() below
+	 * completes. The driver will then mistake the flip done interrupt
+	 * from the mmio flip as the flip done interrupt from the CS flip.
+	 */
+	igt_wait_for_vblank(data->drm_fd, pipe);
+
+	/* now issue the mmio flip w/o vblank waits in the kernel, ie. pan a bit */
+	ret = drmModeSetCrtc(data->drm_fd, output->config.crtc->crtc_id,
+			     green_fb.fb_id, 0, 0, &output->id, 1,
+			     mode);
+	igt_assert(ret == 0);
+
+	make_gpu_busy(data, blue_fb.gem_handle);
+
+	/*
+	 * Submit the CS flip. The commands must be emitted into the ring
+	 * before the mmio flip from the panning operation completes.
+	 */
+	data->flip_done = false;
+	ret = drmModePageFlip(data->drm_fd, output->config.crtc->crtc_id,
+			      blue_fb.fb_id, DRM_MODE_PAGE_FLIP_EVENT, data);
+	igt_assert(ret == 0);
+
+	/*
+	 * Set primary plane to red fb. This should wait for the CS flip
+	 * to complete. But if the kernel mistook the flip done interrupt
+	 * from the mmio flip as the flip done from the CS flip, this will
+	 * not wait for anything. And hence the the CS flip will actually
+	 * occur after this mmio flip.
+	 */
+	ret = drmModeSetCrtc(data->drm_fd, output->config.crtc->crtc_id,
+			     red_fb.fb_id, 0, 0, &output->id, 1,
+			     mode);
+	igt_assert(ret == 0);
+
+	/* Make sure the flip has been executed */
+	wait_for_flip(data, blue_fb.gem_handle);
+
+	/* Grab crc and compare with the extected result */
+	igt_pipe_crc_collect_crc(data->pipe_crc, &crc);
+
+	igt_plane_set_fb(primary, NULL);
+	igt_display_commit(&data->display);
+
+	igt_remove_fb(data->drm_fd, &red_fb);
+	igt_remove_fb(data->drm_fd, &green_fb);
+	igt_remove_fb(data->drm_fd, &blue_fb);
+
+	igt_pipe_crc_free(data->pipe_crc);
+	data->pipe_crc = NULL;
+
+	igt_output_set_pipe(output, PIPE_ANY);
+	igt_display_commit(&data->display);
+
+	igt_assert(igt_crc_equal(&ref_crc, &crc));
+}
+
+static void
+run_plane_test_for_pipe(data_t *data, enum pipe pipe)
+{
+	igt_output_t *output;
+	enum igt_plane plane = 1; /* testing with one sprite is enough */
+
+	igt_skip_on(plane >= data->display.pipes[pipe].n_planes);
+
+	for_each_connected_output(&data->display, output)
+		test_plane(data, output, pipe, plane);
+}
+
+static void
+run_crtc_test_for_pipe(data_t *data, enum pipe pipe)
+{
+	igt_output_t *output;
+
+	for_each_connected_output(&data->display, output)
+		test_crtc(data, output, pipe);
+}
+
+static data_t data;
+
+igt_main
+{
+	int pipe;
+
+	igt_skip_on_simulation();
+
+	igt_fixture {
+		data.drm_fd = drm_open_any();
+
+		igt_set_vt_graphics_mode();
+
+		data.devid = intel_get_drm_devid(data.drm_fd);
+
+		igt_require_pipe_crc();
+		igt_display_init(&data.display, data.drm_fd);
+
+		data.bufmgr = drm_intel_bufmgr_gem_init(data.drm_fd, 4096);
+		igt_assert(data.bufmgr);
+		drm_intel_bufmgr_gem_enable_reuse(data.bufmgr);
+
+		data.busy_bo = drm_intel_bo_alloc(data.bufmgr, "bo",
+						  128*1024*1024, 4096);
+		gem_set_tiling(data.drm_fd, data.busy_bo->handle, 0, 4096);
+	}
+
+	igt_subtest_f("setplane_vs_cs_flip") {
+		for (pipe = 0; pipe < data.display.n_pipes; pipe++)
+			run_plane_test_for_pipe(&data, pipe);
+	}
+
+	igt_subtest_f("setcrtc_vs_cs_flip") {
+		for (pipe = 0; pipe < data.display.n_pipes; pipe++)
+			run_crtc_test_for_pipe(&data, pipe);
+	}
+
+	igt_fixture {
+		drm_intel_bufmgr_destroy(data.bufmgr);
+		igt_display_fini(&data.display);
+	}
+}
-- 
1.8.3.2

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