arch/tile: allow building Linux with transparent huge pages enabled

The change adds some infrastructure for managing tile pmd's more generally,
using pte_pmd() and pmd_pte() methods to translate pmd values to and
from ptes, since on TILEPro a pmd is really just a nested structure
holding a pgd (aka pte).  Several existing pmd methods are moved into
this framework, and a whole raft of additional pmd accessors are defined
that are used by the transparent hugepage framework.

The tile PTE now has a "client2" bit.  The bit is used to indicate a
transparent huge page is in the process of being split into subpages.

This change also fixes a generic bug where the return value of the
generic pmdp_splitting_flush() was incorrect.

Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>

1 files changed, 7 insertions, 22 deletions

diff --git a/arch/tile/include/asm/pgtable_64.h b/arch/tile/include/asm/pgtable_64.h
index fd80328523b4..e105f3ada655 100644
--- a/arch/tile/include/asm/pgtable_64.h
+++ b/arch/tile/include/asm/pgtable_64.h
@@ -108,28 +108,6 @@ static inline unsigned long pud_index(unsigned long address)
 #define pmd_offset(pud, address) \
 	((pmd_t *)pud_page_vaddr(*(pud)) + pmd_index(address))
 
-static inline void __set_pmd(pmd_t *pmdp, pmd_t pmdval)
-{
-	set_pte(pmdp, pmdval);
-}
-
-/* Create a pmd from a PTFN and pgprot. */
-static inline pmd_t ptfn_pmd(unsigned long ptfn, pgprot_t prot)
-{
-	return hv_pte_set_ptfn(prot, ptfn);
-}
-
-/* Return the page-table frame number (ptfn) that a pmd_t points at. */
-static inline unsigned long pmd_ptfn(pmd_t pmd)
-{
-	return hv_pte_get_ptfn(pmd);
-}
-
-static inline void pmd_clear(pmd_t *pmdp)
-{
-	__pte_clear(pmdp);
-}
-
 /* Normalize an address to having the correct high bits set. */
 #define pgd_addr_normalize pgd_addr_normalize
 static inline unsigned long pgd_addr_normalize(unsigned long addr)
@@ -170,6 +148,13 @@ static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 	return hv_pte(__insn_exch(&ptep->val, 0UL));
 }
 
+/*
+ * pmds are the same as pgds and ptes, so converting is a no-op.
+ */
+#define pmd_pte(pmd) (pmd)
+#define pmdp_ptep(pmdp) (pmdp)
+#define pte_pmd(pte) (pte)
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_TILE_PGTABLE_64_H */