[S390] Cleanup in page table related code.

[linux-2.6-omap-h63xx.git] / arch / s390 / mm / init.c

diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c
index a055894f3bd89a59f4e843c1c113ef5ce80547aa..cfd9b8f7a5239b11b7c81272f65474ab80423a02 100644 (file)
--- a/arch/s390/mm/init.c
+++ b/arch/s390/mm/init.c
@@ -9,7 +9,6 @@
  *    Copyright (C) 1995  Linus Torvalds
  */
 
-#include <linux/config.h>
 #include <linux/signal.h>
 #include <linux/sched.h>
 #include <linux/kernel.h>
@@ -24,6 +23,7 @@
 #include <linux/init.h>
 #include <linux/pagemap.h>
 #include <linux/bootmem.h>
+#include <linux/pfn.h>
 
 #include <asm/processor.h>
 #include <asm/system.h>
@@ -34,6 +34,7 @@
 #include <asm/lowcore.h>
 #include <asm/tlb.h>
 #include <asm/tlbflush.h>
+#include <asm/sections.h>
 
 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
 
@@ -90,17 +91,6 @@ void show_mem(void)
         printk("%d pages swap cached\n",cached);
 }
 
-/* References to section boundaries */
-
-extern unsigned long _text;
-extern unsigned long _etext;
-extern unsigned long _edata;
-extern unsigned long __bss_start;
-extern unsigned long _end;
-
-extern unsigned long __init_begin;
-extern unsigned long __init_end;
-
 extern unsigned long __initdata zholes_size[];
 /*
  * paging_init() sets up the page tables
@@ -117,13 +107,24 @@ void __init paging_init(void)
         unsigned long pfn = 0;
         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
         static const int ssm_mask = 0x04000000L;
+       unsigned long ro_start_pfn, ro_end_pfn;
+       unsigned long zones_size[MAX_NR_ZONES];
+
+       ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
+       ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
+
+       memset(zones_size, 0, sizeof(zones_size));
+       zones_size[ZONE_DMA] = max_low_pfn;
+       free_area_init_node(0, &contig_page_data, zones_size,
+                           __pa(PAGE_OFFSET) >> PAGE_SHIFT,
+                           zholes_size);
 
        /* unmap whole virtual address space */
        
         pg_dir = swapper_pg_dir;
 
-       for (i=0;i<KERNEL_PGD_PTRS;i++) 
-               pmd_clear((pmd_t*)pg_dir++);
+       for (i = 0; i < PTRS_PER_PGD; i++)
+               pmd_clear((pmd_t *) pg_dir++);
                
        /*
         * map whole physical memory to virtual memory (identity mapping) 
@@ -135,19 +136,19 @@ void __init paging_init(void)
                 /*
                  * pg_table is physical at this point
                  */
-               pg_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+               pg_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
 
-                pg_dir->pgd0 =  (_PAGE_TABLE | __pa(pg_table));
-                pg_dir->pgd1 =  (_PAGE_TABLE | (__pa(pg_table)+1024));
-                pg_dir->pgd2 =  (_PAGE_TABLE | (__pa(pg_table)+2048));
-                pg_dir->pgd3 =  (_PAGE_TABLE | (__pa(pg_table)+3072));
+               pmd_populate_kernel(&init_mm, (pmd_t *) pg_dir, pg_table);
                 pg_dir++;
 
                 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
-                        pte = pfn_pte(pfn, PAGE_KERNEL);
+                       if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
+                               pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
+                       else
+                               pte = pfn_pte(pfn, PAGE_KERNEL);
                         if (pfn >= max_low_pfn)
-                                pte_clear(&init_mm, 0, &pte);
-                        set_pte(pg_table, pte);
+                               pte_val(pte) = _PAGE_TYPE_EMPTY;
+                       set_pte(pg_table, pte);
                         pfn++;
                 }
         }
@@ -162,20 +163,11 @@ void __init paging_init(void)
                             : : "m" (pgdir_k), "m" (ssm_mask));
 
         local_flush_tlb();
-
-       {
-               unsigned long zones_size[MAX_NR_ZONES];
-
-               memset(zones_size, 0, sizeof(zones_size));
-               zones_size[ZONE_DMA] = max_low_pfn;
-               free_area_init_node(0, &contig_page_data, zones_size,
-                                   __pa(PAGE_OFFSET) >> PAGE_SHIFT,
-                                   zholes_size);
-       }
         return;
 }
 
 #else /* CONFIG_64BIT */
+
 void __init paging_init(void)
 {
         pgd_t * pg_dir;
@@ -187,13 +179,15 @@ void __init paging_init(void)
         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
           _KERN_REGION_TABLE;
        static const int ssm_mask = 0x04000000L;
-
        unsigned long zones_size[MAX_NR_ZONES];
        unsigned long dma_pfn, high_pfn;
+       unsigned long ro_start_pfn, ro_end_pfn;
 
        memset(zones_size, 0, sizeof(zones_size));
        dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
        high_pfn = max_low_pfn;
+       ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
+       ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
 
        if (dma_pfn > high_pfn)
                zones_size[ZONE_DMA] = high_pfn;
@@ -219,7 +213,7 @@ void __init paging_init(void)
                         continue;
                 }          
         
-               pm_dir = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE*4);
+               pm_dir = (pmd_t *) alloc_bootmem_pages(PAGE_SIZE * 4);
                 pgd_populate(&init_mm, pg_dir, pm_dir);
 
                 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
@@ -228,15 +222,16 @@ void __init paging_init(void)
                                 continue; 
                         }          
                         
-                        pt_dir = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
+                       pt_dir = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
        
                         for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
-                                pte = pfn_pte(pfn, PAGE_KERNEL);
-                                if (pfn >= max_low_pfn) {
-                                        pte_clear(&init_mm, 0, &pte); 
-                                        continue;
-                                }
+                               if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
+                                       pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
+                               else
+                                       pte = pfn_pte(pfn, PAGE_KERNEL);
+                               if (pfn >= max_low_pfn)
+                                       pte_val(pte) = _PAGE_TYPE_EMPTY;
                                 set_pte(pt_dir, pte);
                                 pfn++;
                         }
@@ -283,6 +278,9 @@ void __init mem_init(void)
                 reservedpages << (PAGE_SHIFT-10),
                 datasize >>10,
                 initsize >> 10);
+       printk("Write protected kernel read-only data: %#lx - %#lx\n",
+              (unsigned long)&__start_rodata,
+              PFN_ALIGN((unsigned long)&__end_rodata) - 1);
 }
 
 void free_initmem(void)