igt: Add basic exercise of vGEM

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/lib/igt_vgem.c b/lib/igt_vgem.c
new file mode 100644
index 0000000..4fe166a
--- /dev/null
+++ b/lib/igt_vgem.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright © 2016 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.
+ */
+
+#define _GNU_SOURCE
+
+#include "igt.h"
+#include "igt_vgem.h"
+
+#include <sys/mman.h>
+
+int __vgem_create(int fd, struct vgem_bo *bo)
+{
+	struct drm_mode_create_dumb arg;
+
+	memset(&arg, 0, sizeof(arg));
+	arg.width = bo->width;
+	arg.height = bo->height;
+	arg.bpp = bo->bpp;
+
+	if (drmIoctl(fd, DRM_IOCTL_MODE_CREATE_DUMB, &arg))
+		return -errno;
+
+	bo->handle = arg.handle;
+	bo->pitch = arg.pitch;
+	bo->size = arg.size;
+
+	return 0;
+}
+
+void vgem_create(int fd, struct vgem_bo *bo)
+{
+	igt_assert_eq(__vgem_create(fd, bo), 0);
+}
+
+void *__vgem_mmap(int fd, struct vgem_bo *bo, unsigned prot)
+{
+	struct drm_mode_map_dumb arg;
+	void *ptr;
+
+	memset(&arg, 0, sizeof(arg));
+	arg.handle = bo->handle;
+	if (drmIoctl(fd, DRM_IOCTL_MODE_MAP_DUMB, &arg))
+		return NULL;
+
+	ptr = mmap64(0, bo->size, prot, MAP_SHARED, fd, arg.offset);
+	if (ptr == MAP_FAILED)
+		return NULL;
+
+	return ptr;
+}
+
+void *vgem_mmap(int fd, struct vgem_bo *bo, unsigned prot)
+{
+	void *ptr;
+
+	igt_assert_f((ptr = __vgem_mmap(fd, bo, prot)),
+		     "vgem_map(fd=%d, bo->handle=%d, prot=%x)\n",
+		     fd, bo->handle, prot);
+
+	return ptr;
+}
+