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         pud_t *pud;
  85         pmd_t *pmd;
  86         pte_t *pte;
  87         pte_t new_pte;
  88         unsigned long address, end;
  89
  90         address = ((unsigned long)&_stext) & PAGE_MASK;
  91         end = PFN_ALIGN((unsigned long)&_eshared);
  92
  93         for (; address < end; address += PAGE_SIZE) {
  94                 pgd = pgd_offset_k(address);
  95                 pud = pud_offset(pgd, address);
  96                 pmd = pmd_offset(pud, address);
  97                 pte = pte_offset_kernel(pmd, address);
  98                 new_pte = mk_pte_phys(address, __pgprot(_PAGE_RO));
  99                 *pte = new_pte;
 100         }
 101 }
 102
 103 /*
 104  * paging_init() sets up the page tables
 105  */
 106 void __init paging_init(void)
 107 {
 108         static const int ssm_mask = 0x04000000L;
 109         unsigned long max_zone_pfns[MAX_NR_ZONES];
 110         unsigned long pgd_type;
 111
 112         init_mm.pgd = swapper_pg_dir;
 113         S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
 114 #ifdef CONFIG_64BIT
 115         /* A three level page table (4TB) is enough for the kernel space. */
 116         S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
 117         pgd_type = _REGION3_ENTRY_EMPTY;
 118 #else
 119         S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
 120         pgd_type = _SEGMENT_ENTRY_EMPTY;
 121 #endif
 122         clear_table((unsigned long *) init_mm.pgd, pgd_type,
 123                     sizeof(unsigned long)*2048);
 124         vmem_map_init();
 125         setup_ro_region();
 126
 127         /* enable virtual mapping in kernel mode */
 128         __ctl_load(S390_lowcore.kernel_asce, 1, 1);
 129         __ctl_load(S390_lowcore.kernel_asce, 7, 7);
 130         __ctl_load(S390_lowcore.kernel_asce, 13, 13);
 131         __raw_local_irq_ssm(ssm_mask);
 132
 133         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 134 #ifdef CONFIG_ZONE_DMA
 135         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 136 #endif
 137         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 138         free_area_init_nodes(max_zone_pfns);
 139 }
 140
 141 void __init mem_init(void)
 142 {
 143         unsigned long codesize, reservedpages, datasize, initsize;
 144
 145         max_mapnr = num_physpages = max_low_pfn;
 146         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 147
 148         /* clear the zero-page */
 149         memset(empty_zero_page, 0, PAGE_SIZE);
 150
 151         /* this will put all low memory onto the freelists */
 152         totalram_pages += free_all_bootmem();
 153
 154         reservedpages = 0;
 155
 156         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 157         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 158         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 159         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 160                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 161                 max_mapnr << (PAGE_SHIFT-10),
 162                 codesize >> 10,
 163                 reservedpages << (PAGE_SHIFT-10),
 164                 datasize >>10,
 165                 initsize >> 10);
 166         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 167                (unsigned long)&_stext,
 168                PFN_ALIGN((unsigned long)&_eshared) - 1);
 169 }
 170
 171 #ifdef CONFIG_DEBUG_PAGEALLOC
 172 void kernel_map_pages(struct page *page, int numpages, int enable)
 173 {
 174         pgd_t *pgd;
 175         pud_t *pud;
 176         pmd_t *pmd;
 177         pte_t *pte;
 178         unsigned long address;
 179         int i;
 180
 181         for (i = 0; i < numpages; i++) {
 182                 address = page_to_phys(page + i);
 183                 pgd = pgd_offset_k(address);
 184                 pud = pud_offset(pgd, address);
 185                 pmd = pmd_offset(pud, address);
 186                 pte = pte_offset_kernel(pmd, address);
 187                 if (!enable) {
 188                         ptep_invalidate(&init_mm, address, pte);
 189                         continue;
 190                 }
 191                 *pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
 192                 /* Flush cpu write queue. */
 193                 mb();
 194         }
 195 }
 196 #endif
 197
 198 void free_initmem(void)
 199 {
 200         unsigned long addr;
 201
 202         addr = (unsigned long)(&__init_begin);
 203         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 204                 ClearPageReserved(virt_to_page(addr));
 205                 init_page_count(virt_to_page(addr));
 206                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
 207                 free_page(addr);
 208                 totalram_pages++;
 209         }
 210         printk ("Freeing unused kernel memory: %ldk freed\n",
 211                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 212 }
 213
 214 #ifdef CONFIG_BLK_DEV_INITRD
 215 void free_initrd_mem(unsigned long start, unsigned long end)
 216 {
 217         if (start < end)
 218                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 219         for (; start < end; start += PAGE_SIZE) {
 220                 ClearPageReserved(virt_to_page(start));
 221                 init_page_count(virt_to_page(start));
 222                 free_page(start);
 223                 totalram_pages++;
 224         }
 225 }
 226 #endif