s390/mm: introduce defines to reflect the hardware mmu

Add various defines like e.g. _REGION1_SHIFT to reflect the hardware
mmu. We have quite a bit code that does not make use of the Linux
memory management primitives but directly modifies page, segment and
region values.

Most of this is open-coded like e.g. "1UL << 53". In order to clean
this up introduce a couple of new defines. The existing Linux memory
management defines are changed, so the mapping to the hardware
implementation is reflected.
Reviewed-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: NHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/page.h

@@ -10,10 +10,14 @@
 #include <linux/const.h>
 #include <asm/types.h>
 
+#define _PAGE_SHIFT	12
+#define _PAGE_SIZE	(_AC(1, UL) << _PAGE_SHIFT)
+#define _PAGE_MASK	(~(_PAGE_SIZE - 1))
+
 /* PAGE_SHIFT determines the page size */
-#define PAGE_SHIFT      12
-#define PAGE_SIZE	(_AC(1,UL) << PAGE_SHIFT)
-#define PAGE_MASK       (~(PAGE_SIZE-1))
+#define PAGE_SHIFT	_PAGE_SHIFT
+#define PAGE_SIZE	_PAGE_SIZE
+#define PAGE_MASK	_PAGE_MASK
 #define PAGE_DEFAULT_ACC	0
 #define PAGE_DEFAULT_KEY	(PAGE_DEFAULT_ACC << 4)
 

arch/s390/include/asm/pgalloc.h

@@ -15,6 +15,8 @@
 #include <linux/gfp.h>
 #include <linux/mm.h>
 
+#define CRST_ALLOC_ORDER 2
+
 unsigned long *crst_table_alloc(struct mm_struct *);
 void crst_table_free(struct mm_struct *, unsigned long *);
 

arch/s390/include/asm/pgtable.h

@@ -65,26 +65,6 @@ extern unsigned long zero_page_mask;
 
 /* TODO: s390 cannot support io_remap_pfn_range... */
 
-#define PMD_SHIFT	20
-#define PUD_SHIFT	31
-#define P4D_SHIFT	42
-#define PGDIR_SHIFT	53
-
-#define PMD_SIZE        (1UL << PMD_SHIFT)
-#define PMD_MASK        (~(PMD_SIZE-1))
-#define PUD_SIZE	(1UL << PUD_SHIFT)
-#define PUD_MASK	(~(PUD_SIZE-1))
-#define P4D_SIZE	(1UL << P4D_SHIFT)
-#define P4D_MASK	(~(P4D_SIZE-1))
-#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
-#define PGDIR_MASK	(~(PGDIR_SIZE-1))
-
-#define PTRS_PER_PTE	256
-#define PTRS_PER_PMD	2048
-#define PTRS_PER_PUD	2048
-#define PTRS_PER_P4D	2048
-#define PTRS_PER_PGD	2048
-
 #define FIRST_USER_ADDRESS  0UL
 
 #define pte_ERROR(e) \
@@ -314,6 +294,54 @@ static inline int is_module_addr(void *addr)
 #define _SEGMENT_ENTRY_SOFT_DIRTY 0x0000 /* SW segment soft dirty bit */
 #endif
 
+#define _CRST_ENTRIES	2048	/* number of region/segment table entries */
+#define _PAGE_ENTRIES	256	/* number of page table entries	*/
+
+#define _CRST_TABLE_SIZE (_CRST_ENTRIES * 8)
+#define _PAGE_TABLE_SIZE (_PAGE_ENTRIES * 8)
+
+#define _REGION1_SHIFT	53
+#define _REGION2_SHIFT	42
+#define _REGION3_SHIFT	31
+#define _SEGMENT_SHIFT	20
+
+#define _REGION1_INDEX	(0x7ffUL << _REGION1_SHIFT)
+#define _REGION2_INDEX	(0x7ffUL << _REGION2_SHIFT)
+#define _REGION3_INDEX	(0x7ffUL << _REGION3_SHIFT)
+#define _SEGMENT_INDEX	(0x7ffUL << _SEGMENT_SHIFT)
+#define _PAGE_INDEX	(0xffUL  << _PAGE_SHIFT)
+
+#define _REGION1_SIZE	(1UL << _REGION1_SHIFT)
+#define _REGION2_SIZE	(1UL << _REGION2_SHIFT)
+#define _REGION3_SIZE	(1UL << _REGION3_SHIFT)
+#define _SEGMENT_SIZE	(1UL << _SEGMENT_SHIFT)
+
+#define _REGION1_MASK	(~(_REGION1_SIZE - 1))
+#define _REGION2_MASK	(~(_REGION2_SIZE - 1))
+#define _REGION3_MASK	(~(_REGION3_SIZE - 1))
+#define _SEGMENT_MASK	(~(_SEGMENT_SIZE - 1))
+
+#define PMD_SHIFT	_SEGMENT_SHIFT
+#define PUD_SHIFT	_REGION3_SHIFT
+#define P4D_SHIFT	_REGION2_SHIFT
+#define PGDIR_SHIFT	_REGION1_SHIFT
+
+#define PMD_SIZE	_SEGMENT_SIZE
+#define PUD_SIZE	_REGION3_SIZE
+#define P4D_SIZE	_REGION2_SIZE
+#define PGDIR_SIZE	_REGION1_SIZE
+
+#define PMD_MASK	_SEGMENT_MASK
+#define PUD_MASK	_REGION3_MASK
+#define P4D_MASK	_REGION2_MASK
+#define PGDIR_MASK	_REGION1_MASK
+
+#define PTRS_PER_PTE	_PAGE_ENTRIES
+#define PTRS_PER_PMD	_CRST_ENTRIES
+#define PTRS_PER_PUD	_CRST_ENTRIES
+#define PTRS_PER_P4D	_CRST_ENTRIES
+#define PTRS_PER_PGD	_CRST_ENTRIES
+
 /*
  * Segment table and region3 table entry encoding
  * (R = read-only, I = invalid, y = young bit):