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