+enum test_read_write {
+ READ_BEFORE_WRITE,
+ READ_AFTER_WRITE,
+};
+
+static void
+test_read_write(int fd, enum test_read_write order)
+{
+ uint32_t handle;
+ void *ptr;
+ volatile uint32_t val = 0;
+
+ handle = gem_create(fd, OBJECT_SIZE);
+
+ ptr = gem_mmap(fd, handle, OBJECT_SIZE, PROT_READ | PROT_WRITE);
+ igt_assert(ptr != MAP_FAILED);
+
+ if (order == READ_BEFORE_WRITE) {
+ val = *(uint32_t *)ptr;
+ *(uint32_t *)ptr = val;
+ } else {
+ *(uint32_t *)ptr = val;
+ val = *(uint32_t *)ptr;
+ }
+
+ gem_close(fd, handle);
+ munmap(ptr, OBJECT_SIZE);
+}
+
+static void
+test_read_write2(int fd, enum test_read_write order)
+{
+ uint32_t handle;
+ void *r, *w;
+ volatile uint32_t val = 0;
+
+ handle = gem_create(fd, OBJECT_SIZE);
+
+ r = gem_mmap(fd, handle, OBJECT_SIZE, PROT_READ);
+ igt_assert(r != MAP_FAILED);
+
+ w = gem_mmap(fd, handle, OBJECT_SIZE, PROT_READ | PROT_WRITE);
+ igt_assert(w != MAP_FAILED);
+
+ if (order == READ_BEFORE_WRITE) {
+ val = *(uint32_t *)r;
+ *(uint32_t *)w = val;
+ } else {
+ *(uint32_t *)w = val;
+ val = *(uint32_t *)r;
+ }
+
+ gem_close(fd, handle);
+ munmap(r, OBJECT_SIZE);
+ munmap(w, OBJECT_SIZE);
+}
+