[S390] refactor page table functions for better pgste support
Rework the architecture page table functions to access the bits in the
page table extension array (pgste). There are a number of changes:
1) Fix missing pgste update if the attach_count for the mm is <= 1.
2) For every operation that affects the invalid bit in the pte or the
rcp byte in the pgste the pcl lock needs to be acquired. The function
pgste_get_lock gets the pcl lock and returns the current pgste value
for a pte pointer. The function pgste_set_unlock stores the pgste
and releases the lock. Between these two calls the bits in the pgste
can be shuffled.
3) Define two software bits in the pte _PAGE_SWR and _PAGE_SWC to avoid
calling SetPageDirty and SetPageReferenced from pgtable.h. If the
host reference backup bit or the host change backup bit has been
set the dirty/referenced state is transfered to the pte. The common
code will pick up the state from the pte.
4) Add ptep_modify_prot_start and ptep_modify_prot_commit for mprotect.
5) Remove pgd_populate_kernel, pud_populate_kernel, pmd_populate_kernel
pgd_clear_kernel, pud_clear_kernel, pmd_clear_kernel and ptep_invalidate.
6) Rename kvm_s390_test_and_clear_page_dirty to
ptep_test_and_clear_user_dirty and add ptep_test_and_clear_user_young.
7) Define mm_exclusive() and mm_has_pgste() helper to improve readability.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
index 739ff9e..f6314af 100644
--- a/arch/s390/include/asm/pgalloc.h
+++ b/arch/s390/include/asm/pgalloc.h
@@ -65,10 +65,7 @@
#define pmd_free(mm, x) do { } while (0)
#define pgd_populate(mm, pgd, pud) BUG()
-#define pgd_populate_kernel(mm, pgd, pud) BUG()
-
#define pud_populate(mm, pud, pmd) BUG()
-#define pud_populate_kernel(mm, pud, pmd) BUG()
#else /* __s390x__ */
@@ -102,26 +99,14 @@
}
#define pmd_free(mm, pmd) crst_table_free(mm, (unsigned long *) pmd)
-static inline void pgd_populate_kernel(struct mm_struct *mm,
- pgd_t *pgd, pud_t *pud)
+static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
{
pgd_val(*pgd) = _REGION2_ENTRY | __pa(pud);
}
-static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
-{
- pgd_populate_kernel(mm, pgd, pud);
-}
-
-static inline void pud_populate_kernel(struct mm_struct *mm,
- pud_t *pud, pmd_t *pmd)
-{
- pud_val(*pud) = _REGION3_ENTRY | __pa(pmd);
-}
-
static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
{
- pud_populate_kernel(mm, pud, pmd);
+ pud_val(*pud) = _REGION3_ENTRY | __pa(pmd);
}
#endif /* __s390x__ */
@@ -134,17 +119,13 @@
}
#define pgd_free(mm, pgd) crst_table_free(mm, (unsigned long *) pgd)
-static inline void pmd_populate_kernel(struct mm_struct *mm,
- pmd_t *pmd, pte_t *pte)
+static inline void pmd_populate(struct mm_struct *mm,
+ pmd_t *pmd, pgtable_t pte)
{
pmd_val(*pmd) = _SEGMENT_ENTRY + __pa(pte);
}
-static inline void pmd_populate(struct mm_struct *mm,
- pmd_t *pmd, pgtable_t pte)
-{
- pmd_populate_kernel(mm, pmd, pte);
-}
+#define pmd_populate_kernel(mm, pmd, pte) pmd_populate(mm, pmd, pte)
#define pmd_pgtable(pmd) \
(pgtable_t)(pmd_val(pmd) & -sizeof(pte_t)*PTRS_PER_PTE)