diff --git a/lib/drmtest.c b/lib/drmtest.c
index 6ee602cd..40f3ac58 100644
--- a/lib/drmtest.c
+++ b/lib/drmtest.c
@@ -32,10 +32,12 @@
 #include <string.h>
 #include <sys/mman.h>
 #include <signal.h>
+#include <pciaccess.h>
 
 #include "drmtest.h"
 #include "i915_drm.h"
 #include "intel_chipset.h"
+#include "intel_gpu_tools.h"
 
 /* This file contains a bunch of wrapper functions to directly use gem ioctls.
  * Mostly useful to write kernel tests. */
@@ -58,7 +60,6 @@ is_intel(int fd)
 /* Ensure the gpu is idle by launching a nop execbuf and stalling for it. */
 void gem_quiescent_gpu(int fd)
 {
-#define MI_BATCH_BUFFER_END	(0xA<<23)
 	uint32_t batch[2] = {MI_BATCH_BUFFER_END, 0};
 	uint32_t handle;
 	struct drm_i915_gem_execbuffer2 execbuf;
@@ -274,6 +275,20 @@ uint64_t gem_aperture_size(int fd)
 	return aperture.aper_size;
 }
 
+uint64_t gem_mappable_aperture_size(void)
+{
+	struct pci_device *pci_dev;
+	int bar;
+	pci_dev = intel_get_pci_device();
+
+	if (intel_gen(pci_dev->device_id) < 3)
+		bar = 0;
+	else
+		bar = 2;
+
+	return pci_dev->regions[bar].size;
+}
+
 static pid_t signal_helper = -1;
 long long int sig_stat;
 static void signal_helper_process(pid_t pid)
diff --git a/lib/drmtest.h b/lib/drmtest.h
index 9b0e6483..dc69b430 100644
--- a/lib/drmtest.h
+++ b/lib/drmtest.h
@@ -48,6 +48,7 @@ void gem_sync(int fd, uint32_t handle);
 uint32_t gem_create(int fd, int size);
 void *gem_mmap(int fd, uint32_t handle, int size, int prot);
 uint64_t gem_aperture_size(int fd);
+uint64_t gem_mappable_aperture_size(void);
 
 void drmtest_fork_signal_helper(void);
 void drmtest_stop_signal_helper(void);