arch/s390/mm/init.c

   1 /*
   2  *  arch/s390/mm/init.c
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Hartmut Penner (hp@de.ibm.com)
   7  *
   8  *  Derived from "arch/i386/mm/init.c"
   9  *    Copyright (C) 1995  Linus Torvalds
  10  */
  11
  12 #include <linux/signal.h>
  13 #include <linux/sched.h>
  14 #include <linux/kernel.h>
  15 #include <linux/errno.h>
  16 #include <linux/string.h>
  17 #include <linux/types.h>
  18 #include <linux/ptrace.h>
  19 #include <linux/mman.h>
  20 #include <linux/mm.h>
  21 #include <linux/swap.h>
  22 #include <linux/smp.h>
  23 #include <linux/init.h>
  24 #include <linux/pagemap.h>
  25 #include <linux/bootmem.h>
  26 #include <linux/pfn.h>
  27 #include <linux/poison.h>
  28 #include <linux/initrd.h>
  29 #include <asm/processor.h>
  30 #include <asm/system.h>
  31 #include <asm/uaccess.h>
  32 #include <asm/pgtable.h>
  33 #include <asm/pgalloc.h>
  34 #include <asm/dma.h>
  35 #include <asm/lowcore.h>
  36 #include <asm/tlb.h>
  37 #include <asm/tlbflush.h>
  38 #include <asm/sections.h>
  39
  40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  41
  42 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  43 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
  44
  45 void show_mem(void)
  46 {
  47         int i, total = 0, reserved = 0;
  48         int shared = 0, cached = 0;
  49         struct page *page;
  50
  51         printk("Mem-info:\n");
  52         show_free_areas();
  53         printk("Free swap:       %6ldkB\n", nr_swap_pages << (PAGE_SHIFT - 10));
  54         i = max_mapnr;
  55         while (i-- > 0) {
  56                 if (!pfn_valid(i))
  57                         continue;
  58                 page = pfn_to_page(i);
  59                 total++;
  60                 if (PageReserved(page))
  61                         reserved++;
  62                 else if (PageSwapCache(page))
  63                         cached++;
  64                 else if (page_count(page))
  65                         shared += page_count(page) - 1;
  66         }
  67         printk("%d pages of RAM\n", total);
  68         printk("%d reserved pages\n", reserved);
  69         printk("%d pages shared\n", shared);
  70         printk("%d pages swap cached\n", cached);
  71
  72         printk("%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
  73         printk("%lu pages writeback\n", global_page_state(NR_WRITEBACK));
  74         printk("%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
  75         printk("%lu pages slab\n",
  76                global_page_state(NR_SLAB_RECLAIMABLE) +
  77                global_page_state(NR_SLAB_UNRECLAIMABLE));
  78         printk("%lu pages pagetables\n", global_page_state(NR_PAGETABLE));
  79 }
  80
  81 static void __init setup_ro_region(void)
  82 {
  83         pgd_t *pgd;
  84         pmd_t *pmd;
  85         pte_t *pte;
  86         pte_t new_pte;
  87         unsigned long address, end;
  88
  89         address = ((unsigned long)&_stext) & PAGE_MASK;
  90         end = PFN_ALIGN((unsigned long)&_eshared);
  91
  92         for (; address < end; address += PAGE_SIZE) {
  93                 pgd = pgd_offset_k(address);
  94                 pmd = pmd_offset(pgd, address);
  95                 pte = pte_offset_kernel(pmd, address);
  96                 new_pte = mk_pte_phys(address, __pgprot(_PAGE_RO));
  97                 *pte = new_pte;
  98         }
  99 }
 100
 101 /*
 102  * paging_init() sets up the page tables
 103  */
 104 void __init paging_init(void)
 105 {
 106         static const int ssm_mask = 0x04000000L;
 107         unsigned long max_zone_pfns[MAX_NR_ZONES];
 108         unsigned long pgd_type;
 109
 110         init_mm.pgd = swapper_pg_dir;
 111         S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
 112 #ifdef CONFIG_64BIT
 113         S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
 114         pgd_type = _REGION3_ENTRY_EMPTY;
 115 #else
 116         S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
 117         pgd_type = _SEGMENT_ENTRY_EMPTY;
 118 #endif
 119         clear_table((unsigned long *) init_mm.pgd, pgd_type,
 120                     sizeof(unsigned long)*2048);
 121         vmem_map_init();
 122         setup_ro_region();
 123
 124         /* enable virtual mapping in kernel mode */
 125         __ctl_load(S390_lowcore.kernel_asce, 1, 1);
 126         __ctl_load(S390_lowcore.kernel_asce, 7, 7);
 127         __ctl_load(S390_lowcore.kernel_asce, 13, 13);
 128         __raw_local_irq_ssm(ssm_mask);
 129
 130         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 131 #ifdef CONFIG_ZONE_DMA
 132         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 133 #endif
 134         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 135         free_area_init_nodes(max_zone_pfns);
 136 }
 137
 138 void __init mem_init(void)
 139 {
 140         unsigned long codesize, reservedpages, datasize, initsize;
 141
 142         max_mapnr = num_physpages = max_low_pfn;
 143         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 144
 145         /* clear the zero-page */
 146         memset(empty_zero_page, 0, PAGE_SIZE);
 147
 148         /* this will put all low memory onto the freelists */
 149         totalram_pages += free_all_bootmem();
 150
 151         reservedpages = 0;
 152
 153         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 154         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 155         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 156         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 157                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 158                 max_mapnr << (PAGE_SHIFT-10),
 159                 codesize >> 10,
 160                 reservedpages << (PAGE_SHIFT-10),
 161                 datasize >>10,
 162                 initsize >> 10);
 163         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 164                (unsigned long)&_stext,
 165                PFN_ALIGN((unsigned long)&_eshared) - 1);
 166 }
 167
 168 void free_initmem(void)
 169 {
 170         unsigned long addr;
 171
 172         addr = (unsigned long)(&__init_begin);
 173         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 174                 ClearPageReserved(virt_to_page(addr));
 175                 init_page_count(virt_to_page(addr));
 176                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
 177                 free_page(addr);
 178                 totalram_pages++;
 179         }
 180         printk ("Freeing unused kernel memory: %ldk freed\n",
 181                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 182 }
 183
 184 #ifdef CONFIG_BLK_DEV_INITRD
 185 void free_initrd_mem(unsigned long start, unsigned long end)
 186 {
 187         if (start < end)
 188                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 189         for (; start < end; start += PAGE_SIZE) {
 190                 ClearPageReserved(virt_to_page(start));
 191                 init_page_count(virt_to_page(start));
 192                 free_page(start);
 193                 totalram_pages++;
 194         }
 195 }
 196 #endif