On 8/11/21 5:31 AM, Mike Rapoport wrote:
+/*
+ * For ARC, pgtable_t is not struct page *, but pte_t * (to avoid
+ * extraneous page_address() calculations) hence can't use
+ * use asm-generic/pgalloc.h which assumes it being struct page *
+ */
Another reason to leave ARC without asm-generic/pgalloc.h was
__get_order_pte() that other arches don't have.
So this and pgtable_t aliased to pte_t * seemed to me too much to bother
then, but probably it's worth reconsidering with addition of 3rd and 4th
levels.
I agree that savings of not havign page_address() might not be huge.
However asm-generic/pgalloc.h only has pte allocation routines and all
other allocation levels come from arch file
Also for ARCv2, given the arbitrary address split and ensuing paging
levels (as well as support for different page sizes) we will need to
make sure that one page is enough to hold any level's paging using say
BUILD_BUG_ON. In fact that should also be done for 3rd and 4th levels
for sanity.
-Vineet
