lib/drmtest: extract gem_write

Astonishing how many different function signatures are possible for
something that simple.

Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

lib/drmtest.c

@@ -142,3 +142,17 @@ void gem_close(int fd, uint32_t handle)
 	ret = drmIoctl(fd, DRM_IOCTL_GEM_CLOSE, &close_bo);
 	assert(ret == 0);
 }
+
+void gem_write(int fd, uint32_t handle, uint32_t offset, const void *buf, uint32_t size)
+{
+	struct drm_i915_gem_pwrite gem_pwrite;
+	int ret;
+
+	gem_pwrite.handle = handle;
+	gem_pwrite.offset = offset;
+	gem_pwrite.size = size;
+	gem_pwrite.data_ptr = (uintptr_t)buf;
+	ret = drmIoctl(fd, DRM_IOCTL_I915_GEM_PWRITE, &gem_pwrite);
+	assert(ret == 0);
+}
+

lib/drmtest.h

@@ -39,3 +39,4 @@ int drm_open_any_master(void);
 
 void gem_set_tiling(int fd, uint32_t handle, int tiling, int stride);
 void gem_close(int fd, uint32_t handle);
+void gem_write(int fd, uint32_t handle, uint32_t offset,  const void *buf, uint32_t size);