[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/page.h b/arch/s390/include/asm/page.h
index 81ee277..accb372 100644
--- a/arch/s390/include/asm/page.h
+++ b/arch/s390/include/asm/page.h
@@ -90,6 +90,7 @@
*/
typedef struct { unsigned long pgprot; } pgprot_t;
+typedef struct { unsigned long pgste; } pgste_t;
typedef struct { unsigned long pte; } pte_t;
typedef struct { unsigned long pmd; } pmd_t;
typedef struct { unsigned long pud; } pud_t;
@@ -97,13 +98,16 @@
typedef pte_t *pgtable_t;
#define pgprot_val(x) ((x).pgprot)
+#define pgste_val(x) ((x).pgste)
#define pte_val(x) ((x).pte)
#define pmd_val(x) ((x).pmd)
#define pud_val(x) ((x).pud)
#define pgd_val(x) ((x).pgd)
+#define __pgste(x) ((pgste_t) { (x) } )
#define __pte(x) ((pte_t) { (x) } )
#define __pmd(x) ((pmd_t) { (x) } )
+#define __pud(x) ((pud_t) { (x) } )
#define __pgd(x) ((pgd_t) { (x) } )
#define __pgprot(x) ((pgprot_t) { (x) } )