+ /*
+ * Apparently some 32-bit boxes (ARM) will return highmem pages,
+ * which then need to be mapped. We could support that, but it'd
+ * complicate the code and slowdown the common cases quite a bit.
+ * So just error out, returning -EINVAL just like we did on kernels
+ * that didn't support mapped buffer rings.
+ */
+ for (i = 0; i < nr_pages; i++)
+ if (PageHighMem(pages[i]))
+ goto error_unpin;
+