lib: Restore gem_available_aperture_size()

Missed an error whilst rebasing and trying to modify the previous patch
to keep this function intact... Instead, I now have to add this patch to
restore gem_available_aperture_size() and its one usage.

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

lib/ioctl_wrappers.c

@@ -1226,6 +1226,25 @@ bool gem_has_bsd2(int fd)
 		has_bsd2 = gem_has_enable_ring(fd,LOCAL_I915_PARAM_HAS_BSD2);
 	return has_bsd2;
 }
+/**
+ * gem_available_aperture_size:
+ * @fd: open i915 drm file descriptor
+ *
+ * Feature test macro to query the kernel for the available gpu aperture size
+ * usable in a batchbuffer.
+ *
+ * Returns: The available gtt address space size.
+ */
+uint64_t gem_available_aperture_size(int fd)
+{
+	struct drm_i915_gem_get_aperture aperture;
+
+	memset(&aperture, 0, sizeof(aperture));
+	aperture.aper_size = 256*1024*1024;
+	do_ioctl(fd, DRM_IOCTL_I915_GEM_GET_APERTURE, &aperture);
+
+	return aperture.aper_available_size;
+}
 
 /**
  * gem_aperture_size:

lib/ioctl_wrappers.h

@@ -143,6 +143,7 @@ int gem_gtt_type(int fd);
 bool gem_uses_ppgtt(int fd);
 bool gem_uses_full_ppgtt(int fd);
 int gem_available_fences(int fd);
+uint64_t gem_available_aperture_size(int fd);
 uint64_t gem_aperture_size(int fd);
 uint64_t gem_global_aperture_size(int fd);
 uint64_t gem_mappable_aperture_size(void);

tests/kms_rotation_crc.c

@@ -418,7 +418,7 @@ static void test_plane_rotation_exhaust_fences(data_t *data, enum igt_plane plan
 	 * for creating (MAX_FENCES+1) framebuffers.
 	 */
 	total_fbs_size = size * (MAX_FENCES + 1);
-	total_aperture_size = gem_global_aperture_size(fd);
+	total_aperture_size = gem_available_aperture_size(fd);
 	igt_require(total_fbs_size < total_aperture_size * 0.9);
 
 	igt_plane_set_fb(plane, NULL);