[PATCH i-g-t] tests/dumb_buffer: Add subtests for mixing dumb buffers with prime

[Zack Rusin <zack.rusin@broadcom.com>]

New versions of KWin are extensively using dumb buffers with prime. Add
some basic tests to verify that mixing the dumb buffer interface
with prime ends up with a well formed buffer.

Signed-off-by: Zack Rusin <zack.rusin@broadcom.com>
---
 tests/dumb_buffer.c | 94 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 94 insertions(+)

diff --git a/tests/dumb_buffer.c b/tests/dumb_buffer.c
index 8e243459c..62e9b419d 100644
--- a/tests/dumb_buffer.c
+++ b/tests/dumb_buffer.c
@@ -69,6 +69,18 @@
  * SUBTEST: map-uaf
  *
  * SUBTEST: map-valid
+ *
+ * SUBTEST: dmabuf-read
+ * Description: Make a dumb buffer, map it using the dumb buffer interface,
+ *              export it via prime, mmap the prime buffer and check
+ *              that its contents matches what we wrote to the dumb
+ *              buffer.
+ *
+ * SUBTEST: dmabuf-write
+ * Description: Make a dumb buffer, map and write to it using the prime
+ *              interface, than map it using the dumb buffer interface
+ *              and check whether its contents matches what we wrote using
+ * 		the prime interface.
  */
 
 IGT_TEST_DESCRIPTION("This is a test for the generic dumb buffer interface.");
@@ -388,6 +400,82 @@ static void always_clear(int fd, int timeout)
 	igt_info("Checked %'lu page allocations\n", checked);
 }
 
+static const uint32_t pattern[] = {
+	0xff000000, 0x00ff0000, 0x0000ff00, 0x000000ff,
+	0x000000ff, 0x0000ff00, 0x00ff0000, 0xff000000,
+	0x00ffff00, 0xff0000ff, 0x00ff00ff, 0xff00ff00,
+	0xff0000ff, 0x00ff00ff, 0x00ffff00, 0xff00ff00
+};
+
+static void dmabuf_read(int fd)
+{
+	struct drm_mode_create_dumb create = {
+		.width = 64,
+		.height = 64,
+		.bpp = 32,
+	};
+	int dma_buf_fd;
+	uint32_t *ptr;
+
+	dumb_create(fd, &create);
+	ptr = dumb_map(fd, create.handle, create.size, PROT_WRITE);
+	igt_assert(ptr != MAP_FAILED);
+	igt_assert(ptr != NULL);
+	igt_assert(create.size > sizeof(pattern));
+	memcpy(ptr, pattern, sizeof(pattern));
+	munmap(ptr, create.size);
+
+	dma_buf_fd = prime_handle_to_fd_for_mmap(fd, create.handle);
+
+	/* Skip if DRM_RDWR is not supported */
+	igt_skip_on(errno == EINVAL);
+
+	ptr = mmap(NULL, create.size, PROT_READ | PROT_WRITE, MAP_SHARED, dma_buf_fd, 0);
+	igt_assert(ptr != MAP_FAILED);
+
+	/* Check pattern correctness */
+	igt_assert(memcmp(ptr, pattern, sizeof(pattern)) == 0);
+
+	munmap(ptr, create.size);
+	close(dma_buf_fd);
+
+	dumb_destroy(fd, create.handle);
+}
+
+static void dmabuf_write(int fd)
+{
+	struct drm_mode_create_dumb create = {
+		.width = 64,
+		.height = 64,
+		.bpp = 32,
+	};
+	int dma_buf_fd;
+	uint32_t *ptr;
+
+	dumb_create(fd, &create);
+
+	dma_buf_fd = prime_handle_to_fd_for_mmap(fd, create.handle);
+	/* Skip if DRM_RDWR is not supported */
+	igt_skip_on(errno == EINVAL);
+
+	ptr = mmap(NULL, create.size, PROT_READ | PROT_WRITE, MAP_SHARED, dma_buf_fd, 0);
+	igt_assert(ptr != MAP_FAILED);
+	memcpy(ptr, pattern, sizeof(pattern));
+	munmap(ptr, create.size);
+
+
+	ptr = dumb_map(fd, create.handle, create.size, PROT_READ);
+	igt_assert(ptr != MAP_FAILED);
+	igt_assert(ptr != NULL);
+	igt_assert(create.size > sizeof(pattern));
+	igt_assert(memcmp(ptr, pattern, sizeof(pattern)) == 0);
+	munmap(ptr, create.size);
+
+	close(dma_buf_fd);
+
+	dumb_destroy(fd, create.handle);
+}
+
 igt_main
 {
 	int fd = -1;
@@ -414,6 +502,12 @@ igt_main
 	igt_subtest("create-clear")
 		always_clear(fd, 30);
 
+	igt_subtest("dmabuf-read")
+		dmabuf_read(fd);
+
+	igt_subtest("dmabuf-write")
+		dmabuf_write(fd);
+
 	igt_fixture {
 		drm_close_driver(fd);
 	}
-- 
2.40.1