[S390] Cleanup page table definitions.

- De-confuse the defines for the address-space-control-elements
  and the segment/region table entries.
- Create out of line functions for page table allocation / freeing.
- Simplify get_shadow_xxx functions.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 12 insertions, 16 deletions

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index 3a25bbf2eb0a..90ec058aa7db 100644
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -103,32 +103,28 @@ static void __init setup_ro_region(void)
  */
 void __init paging_init(void)
 {
-        pgd_t *pg_dir;
-        int i;
-        unsigned long pgdir_k;
         static const int ssm_mask = 0x04000000L;
         unsigned long max_zone_pfns[MAX_NR_ZONES];
+        unsigned long pgd_type;
 
-        pg_dir = swapper_pg_dir;
-        
+        init_mm.pgd = swapper_pg_dir;
+        S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
 #ifdef CONFIG_64BIT
-        pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERN_REGION_TABLE;
-        for (i = 0; i < PTRS_PER_PGD; i++)
-                pgd_clear_kernel(pg_dir + i);
+        S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
+        pgd_type = _REGION3_ENTRY_EMPTY;
 #else
-        pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
-        for (i = 0; i < PTRS_PER_PGD; i++)
-                pmd_clear_kernel((pmd_t *)(pg_dir + i));
+        S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
+        pgd_type = _SEGMENT_ENTRY_EMPTY;
 #endif
+        clear_table((unsigned long *) init_mm.pgd, pgd_type,
+                    sizeof(unsigned long)*2048);
         vmem_map_init();
         setup_ro_region();
 
-        S390_lowcore.kernel_asce = pgdir_k;
-
         /* enable virtual mapping in kernel mode */
-        __ctl_load(pgdir_k, 1, 1);
-        __ctl_load(pgdir_k, 7, 7);
-        __ctl_load(pgdir_k, 13, 13);
+        __ctl_load(S390_lowcore.kernel_asce, 1, 1);
+        __ctl_load(S390_lowcore.kernel_asce, 7, 7);
+        __ctl_load(S390_lowcore.kernel_asce, 13, 13);
         __raw_local_irq_ssm(ssm_mask);
 
         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));