powerpc: New hugepage directory format
Change the hugepage directory format so that we can have leaf ptes directly
at page directory avoiding the allocation of hugepage directory.
With the new table format we have 3 cases for pgds and pmds:
(1) invalid (all zeroes)
(2) pointer to next table, as normal; bottom 6 bits == 0
(4) hugepd pointer, bottom two bits == 00, next 4 bits indicate size of table
Instead of storing shift value in hugepd pointer we use mmu_psize_def index
so that we can fit all the supported hugepage size in 4 bits
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/mm/hugetlbpage.c b/arch/powerpc/mm/hugetlbpage.c
index 5dc52d80..b4e2f24 100644
--- a/arch/powerpc/mm/hugetlbpage.c
+++ b/arch/powerpc/mm/hugetlbpage.c
@@ -48,23 +48,6 @@
static unsigned nr_gpages;
#endif
-static inline int shift_to_mmu_psize(unsigned int shift)
-{
- int psize;
-
- for (psize = 0; psize < MMU_PAGE_COUNT; ++psize)
- if (mmu_psize_defs[psize].shift == shift)
- return psize;
- return -1;
-}
-
-static inline unsigned int mmu_psize_to_shift(unsigned int mmu_psize)
-{
- if (mmu_psize_defs[mmu_psize].shift)
- return mmu_psize_defs[mmu_psize].shift;
- BUG();
-}
-
#define hugepd_none(hpd) ((hpd).pd == 0)
pte_t *find_linux_pte_or_hugepte(pgd_t *pgdir, unsigned long ea, unsigned *shift)
@@ -145,6 +128,7 @@
if (unlikely(!hugepd_none(*hpdp)))
break;
else
+ /* We use the old format for PPC_FSL_BOOK3E */
hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift;
}
/* If we bailed from the for loop early, an error occurred, clean up */
@@ -156,9 +140,15 @@
#else
if (!hugepd_none(*hpdp))
kmem_cache_free(cachep, new);
- else
+ else {
+#ifdef CONFIG_PPC_BOOK3S_64
+ hpdp->pd = (unsigned long)new |
+ (shift_to_mmu_psize(pshift) << 2);
+#else
hpdp->pd = ((unsigned long)new & ~PD_HUGE) | pshift;
#endif
+ }
+#endif
spin_unlock(&mm->page_table_lock);
return 0;
}
