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         unsigned long i, total = 0, reserved = 0;
  48         unsigned long shared = 0, cached = 0;
  49         unsigned long flags;
  50         struct page *page;
  51         pg_data_t *pgdat;
  52
  53         printk("Mem-info:\n");
  54         show_free_areas();
  55         for_each_online_pgdat(pgdat) {
  56                 pgdat_resize_lock(pgdat, &flags);
  57                 for (i = 0; i < pgdat->node_spanned_pages; i++) {
  58                         if (!pfn_valid(pgdat->node_start_pfn + i))
  59                                 continue;
  60                         page = pfn_to_page(pgdat->node_start_pfn + i);
  61                         total++;
  62                         if (PageReserved(page))
  63                                 reserved++;
  64                         else if (PageSwapCache(page))
  65                                 cached++;
  66                         else if (page_count(page))
  67                                 shared += page_count(page) - 1;
  68                 }
  69                 pgdat_resize_unlock(pgdat, &flags);
  70         }
  71         printk("%ld pages of RAM\n", total);
  72         printk("%ld reserved pages\n", reserved);
  73         printk("%ld pages shared\n", shared);
  74         printk("%ld pages swap cached\n", cached);
  75 }
  76
  77 /*
  78  * paging_init() sets up the page tables
  79  */
  80 void __init paging_init(void)
  81 {
  82         static const int ssm_mask = 0x04000000L;
  83         unsigned long max_zone_pfns[MAX_NR_ZONES];
  84         unsigned long pgd_type;
  85
  86         init_mm.pgd = swapper_pg_dir;
  87         S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
  88 #ifdef CONFIG_64BIT
  89         /* A three level page table (4TB) is enough for the kernel space. */
  90         S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
  91         pgd_type = _REGION3_ENTRY_EMPTY;
  92 #else
  93         S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
  94         pgd_type = _SEGMENT_ENTRY_EMPTY;
  95 #endif
  96         clear_table((unsigned long *) init_mm.pgd, pgd_type,
  97                     sizeof(unsigned long)*2048);
  98         vmem_map_init();
  99
 100         /* enable virtual mapping in kernel mode */
 101         __ctl_load(S390_lowcore.kernel_asce, 1, 1);
 102         __ctl_load(S390_lowcore.kernel_asce, 7, 7);
 103         __ctl_load(S390_lowcore.kernel_asce, 13, 13);
 104         __raw_local_irq_ssm(ssm_mask);
 105
 106         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 107         sparse_init();
 108         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 109 #ifdef CONFIG_ZONE_DMA
 110         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 111 #endif
 112         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 113         free_area_init_nodes(max_zone_pfns);
 114 }
 115
 116 void __init mem_init(void)
 117 {
 118         unsigned long codesize, reservedpages, datasize, initsize;
 119
 120         max_mapnr = num_physpages = max_low_pfn;
 121         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 122
 123         /* clear the zero-page */
 124         memset(empty_zero_page, 0, PAGE_SIZE);
 125
 126         /* Setup guest page hinting */
 127         cmma_init();
 128
 129         /* this will put all low memory onto the freelists */
 130         totalram_pages += free_all_bootmem();
 131
 132         reservedpages = 0;
 133
 134         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 135         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 136         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 137         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 138                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 139                 max_mapnr << (PAGE_SHIFT-10),
 140                 codesize >> 10,
 141                 reservedpages << (PAGE_SHIFT-10),
 142                 datasize >>10,
 143                 initsize >> 10);
 144         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 145                (unsigned long)&_stext,
 146                PFN_ALIGN((unsigned long)&_eshared) - 1);
 147 }
 148
 149 #ifdef CONFIG_DEBUG_PAGEALLOC
 150 void kernel_map_pages(struct page *page, int numpages, int enable)
 151 {
 152         pgd_t *pgd;
 153         pud_t *pud;
 154         pmd_t *pmd;
 155         pte_t *pte;
 156         unsigned long address;
 157         int i;
 158
 159         for (i = 0; i < numpages; i++) {
 160                 address = page_to_phys(page + i);
 161                 pgd = pgd_offset_k(address);
 162                 pud = pud_offset(pgd, address);
 163                 pmd = pmd_offset(pud, address);
 164                 pte = pte_offset_kernel(pmd, address);
 165                 if (!enable) {
 166                         ptep_invalidate(&init_mm, address, pte);
 167                         continue;
 168                 }
 169                 *pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
 170                 /* Flush cpu write queue. */
 171                 mb();
 172         }
 173 }
 174 #endif
 175
 176 void free_initmem(void)
 177 {
 178         unsigned long addr;
 179
 180         addr = (unsigned long)(&__init_begin);
 181         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 182                 ClearPageReserved(virt_to_page(addr));
 183                 init_page_count(virt_to_page(addr));
 184                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
 185                 free_page(addr);
 186                 totalram_pages++;
 187         }
 188         printk ("Freeing unused kernel memory: %ldk freed\n",
 189                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 190 }
 191
 192 #ifdef CONFIG_BLK_DEV_INITRD
 193 void free_initrd_mem(unsigned long start, unsigned long end)
 194 {
 195         if (start < end)
 196                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 197         for (; start < end; start += PAGE_SIZE) {
 198                 ClearPageReserved(virt_to_page(start));
 199                 init_page_count(virt_to_page(start));
 200                 free_page(start);
 201                 totalram_pages++;
 202         }
 203 }
 204 #endif