igt/gem_mmap_gtt: Check coherency between GTT and CPU mmappings with LLC

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

3 files changed, 44 insertions, 0 deletions

diff --git a/lib/ioctl_wrappers.c b/lib/ioctl_wrappers.c
index c4e10808..39afc874 100644
--- a/lib/ioctl_wrappers.c
+++ b/lib/ioctl_wrappers.c
@@ -643,6 +643,22 @@ int gem_available_fences(int fd)
 	return val;
 }
 
+bool gem_has_llc(int fd)
+{
+	struct drm_i915_getparam gp;
+	int val = 0;
+
+	memset(&gp, 0, sizeof(gp));
+	gp.param = I915_PARAM_HAS_LLC;
+	gp.value = &val;
+
+	if (ioctl(fd, DRM_IOCTL_I915_GETPARAM, &gp, sizeof(gp)))
+		return 0;
+
+	errno = 0;
+	return val;
+}
+
 /**
  * gem_get_num_rings:
  * @fd: open i915 drm file descriptor
diff --git a/lib/ioctl_wrappers.h b/lib/ioctl_wrappers.h
index 310d82ea..b1deedf5 100644
--- a/lib/ioctl_wrappers.h
+++ b/lib/ioctl_wrappers.h
@@ -78,6 +78,7 @@ void gem_sw_finish(int fd, uint32_t handle);
 bool gem_bo_busy(int fd, uint32_t handle);
 
 /* feature test helpers */
+bool gem_has_llc(int fd);
 int gem_get_num_rings(int fd);
 bool gem_has_enable_ring(int fd,int param);
 bool gem_has_bsd(int fd);
diff --git a/tests/gem_mmap_gtt.c b/tests/gem_mmap_gtt.c
index 6fad80a3..35c856f4 100644
--- a/tests/gem_mmap_gtt.c
+++ b/tests/gem_mmap_gtt.c
@@ -273,6 +273,31 @@ test_read(int fd)
 	munmap(dst, OBJECT_SIZE);
 }
 
+static void
+test_write_cpu_read_gtt(int fd)
+{
+	uint32_t handle;
+	uint32_t *src, *dst;
+
+	igt_require(gem_has_llc(fd));
+
+	handle = gem_create(fd, OBJECT_SIZE);
+
+	dst = gem_mmap(fd, handle, OBJECT_SIZE, PROT_READ);
+	igt_assert(dst != (uint32_t *)MAP_FAILED);
+
+	src = gem_mmap__cpu(fd, handle, OBJECT_SIZE, PROT_WRITE);
+	igt_assert(src != (uint32_t *)MAP_FAILED);
+
+	gem_close(fd, handle);
+
+	memset(src, 0xaa, OBJECT_SIZE);
+	igt_assert(memcmp(dst, src, OBJECT_SIZE) == 0);
+
+	munmap(src, OBJECT_SIZE);
+	munmap(dst, OBJECT_SIZE);
+}
+
 struct thread_fault_concurrent {
 	pthread_t thread;
 	int id;
@@ -368,6 +393,8 @@ igt_main
 		run_without_prefault(fd, test_write);
 	igt_subtest("write-gtt-no-prefault")
 		run_without_prefault(fd, test_write_gtt);
+	igt_subtest("write-cpu-read-gtt")
+		test_write_cpu_read_gtt(fd);
 
 	igt_fixture
 		close(fd);