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 diag10(unsigned long addr)
  46 {
  47         if (addr >= 0x7ff00000)
  48                 return;
  49         asm volatile(
  50 #ifdef CONFIG_64BIT
  51                 "       sam31\n"
  52                 "       diag    %0,%0,0x10\n"
  53                 "0:     sam64\n"
  54 #else
  55                 "       diag    %0,%0,0x10\n"
  56                 "0:\n"
  57 #endif
  58                 EX_TABLE(0b,0b)
  59                 : : "a" (addr));
  60 }
  61
  62 void show_mem(void)
  63 {
  64         int i, total = 0, reserved = 0;
  65         int shared = 0, cached = 0;
  66         struct page *page;
  67
  68         printk("Mem-info:\n");
  69         show_free_areas();
  70         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  71         i = max_mapnr;
  72         while (i-- > 0) {
  73                 if (!pfn_valid(i))
  74                         continue;
  75                 page = pfn_to_page(i);
  76                 total++;
  77                 if (PageReserved(page))
  78                         reserved++;
  79                 else if (PageSwapCache(page))
  80                         cached++;
  81                 else if (page_count(page))
  82                         shared += page_count(page) - 1;
  83         }
  84         printk("%d pages of RAM\n",total);
  85         printk("%d reserved pages\n",reserved);
  86         printk("%d pages shared\n",shared);
  87         printk("%d pages swap cached\n",cached);
  88 }
  89
  90 static void __init setup_ro_region(void)
  91 {
  92         pgd_t *pgd;
  93         pmd_t *pmd;
  94         pte_t *pte;
  95         pte_t new_pte;
  96         unsigned long address, end;
  97
  98         address = ((unsigned long)&_stext) & PAGE_MASK;
  99         end = PFN_ALIGN((unsigned long)&_eshared);
 100
 101         for (; address < end; address += PAGE_SIZE) {
 102                 pgd = pgd_offset_k(address);
 103                 pmd = pmd_offset(pgd, address);
 104                 pte = pte_offset_kernel(pmd, address);
 105                 new_pte = mk_pte_phys(address, __pgprot(_PAGE_RO));
 106                 *pte = new_pte;
 107         }
 108 }
 109
 110 /*
 111  * paging_init() sets up the page tables
 112  */
 113 void __init paging_init(void)
 114 {
 115         pgd_t *pg_dir;
 116         int i;
 117         unsigned long pgdir_k;
 118         static const int ssm_mask = 0x04000000L;
 119         unsigned long max_zone_pfns[MAX_NR_ZONES];
 120
 121         pg_dir = swapper_pg_dir;
 122
 123 #ifdef CONFIG_64BIT
 124         pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERN_REGION_TABLE;
 125         for (i = 0; i < PTRS_PER_PGD; i++)
 126                 pgd_clear_kernel(pg_dir + i);
 127 #else
 128         pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
 129         for (i = 0; i < PTRS_PER_PGD; i++)
 130                 pmd_clear_kernel((pmd_t *)(pg_dir + i));
 131 #endif
 132         vmem_map_init();
 133         setup_ro_region();
 134
 135         S390_lowcore.kernel_asce = pgdir_k;
 136
 137         /* enable virtual mapping in kernel mode */
 138         __ctl_load(pgdir_k, 1, 1);
 139         __ctl_load(pgdir_k, 7, 7);
 140         __ctl_load(pgdir_k, 13, 13);
 141         __raw_local_irq_ssm(ssm_mask);
 142
 143         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 144 #ifdef CONFIG_ZONE_DMA
 145         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 146 #endif
 147         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 148         free_area_init_nodes(max_zone_pfns);
 149 }
 150
 151 void __init mem_init(void)
 152 {
 153         unsigned long codesize, reservedpages, datasize, initsize;
 154
 155         max_mapnr = num_physpages = max_low_pfn;
 156         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 157
 158         /* clear the zero-page */
 159         memset(empty_zero_page, 0, PAGE_SIZE);
 160
 161         /* this will put all low memory onto the freelists */
 162         totalram_pages += free_all_bootmem();
 163
 164         reservedpages = 0;
 165
 166         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 167         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 168         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 169         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 170                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 171                 max_mapnr << (PAGE_SHIFT-10),
 172                 codesize >> 10,
 173                 reservedpages << (PAGE_SHIFT-10),
 174                 datasize >>10,
 175                 initsize >> 10);
 176         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 177                (unsigned long)&_stext,
 178                PFN_ALIGN((unsigned long)&_eshared) - 1);
 179 }
 180
 181 void free_initmem(void)
 182 {
 183         unsigned long addr;
 184
 185         addr = (unsigned long)(&__init_begin);
 186         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 187                 ClearPageReserved(virt_to_page(addr));
 188                 init_page_count(virt_to_page(addr));
 189                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
 190                 free_page(addr);
 191                 totalram_pages++;
 192         }
 193         printk ("Freeing unused kernel memory: %ldk freed\n",
 194                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 195 }
 196
 197 #ifdef CONFIG_BLK_DEV_INITRD
 198 void free_initrd_mem(unsigned long start, unsigned long end)
 199 {
 200         if (start < end)
 201                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 202         for (; start < end; start += PAGE_SIZE) {
 203                 ClearPageReserved(virt_to_page(start));
 204                 init_page_count(virt_to_page(start));
 205                 free_page(start);
 206                 totalram_pages++;
 207         }
 208 }
 209 #endif