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
  30 #include <asm/processor.h>
  31 #include <asm/system.h>
  32 #include <asm/uaccess.h>
  33 #include <asm/pgtable.h>
  34 #include <asm/pgalloc.h>
  35 #include <asm/dma.h>
  36 #include <asm/lowcore.h>
  37 #include <asm/tlb.h>
  38 #include <asm/tlbflush.h>
  39 #include <asm/sections.h>
  40
  41 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  42
  43 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  44 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
  45
  46 void diag10(unsigned long addr)
  47 {
  48         if (addr >= 0x7ff00000)
  49                 return;
  50         asm volatile(
  51 #ifdef CONFIG_64BIT
  52                 "       sam31\n"
  53                 "       diag    %0,%0,0x10\n"
  54                 "0:     sam64\n"
  55 #else
  56                 "       diag    %0,%0,0x10\n"
  57                 "0:\n"
  58 #endif
  59                 EX_TABLE(0b,0b)
  60                 : : "a" (addr));
  61 }
  62
  63 void show_mem(void)
  64 {
  65         int i, total = 0, reserved = 0;
  66         int shared = 0, cached = 0;
  67         struct page *page;
  68
  69         printk("Mem-info:\n");
  70         show_free_areas();
  71         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  72         i = max_mapnr;
  73         while (i-- > 0) {
  74                 if (!pfn_valid(i))
  75                         continue;
  76                 page = pfn_to_page(i);
  77                 total++;
  78                 if (PageReserved(page))
  79                         reserved++;
  80                 else if (PageSwapCache(page))
  81                         cached++;
  82                 else if (page_count(page))
  83                         shared += page_count(page) - 1;
  84         }
  85         printk("%d pages of RAM\n",total);
  86         printk("%d reserved pages\n",reserved);
  87         printk("%d pages shared\n",shared);
  88         printk("%d pages swap cached\n",cached);
  89 }
  90
  91 static void __init setup_ro_region(void)
  92 {
  93         pgd_t *pgd;
  94         pmd_t *pmd;
  95         pte_t *pte;
  96         pte_t new_pte;
  97         unsigned long address, end;
  98
  99         address = ((unsigned long)&__start_rodata) & PAGE_MASK;
 100         end = PFN_ALIGN((unsigned long)&__end_rodata);
 101
 102         for (; address < end; address += PAGE_SIZE) {
 103                 pgd = pgd_offset_k(address);
 104                 pmd = pmd_offset(pgd, address);
 105                 pte = pte_offset_kernel(pmd, address);
 106                 new_pte = mk_pte_phys(address, __pgprot(_PAGE_RO));
 107                 *pte = new_pte;
 108         }
 109 }
 110
 111 /*
 112  * paging_init() sets up the page tables
 113  */
 114 void __init paging_init(void)
 115 {
 116         pgd_t *pg_dir;
 117         int i;
 118         unsigned long pgdir_k;
 119         static const int ssm_mask = 0x04000000L;
 120         unsigned long max_zone_pfns[MAX_NR_ZONES];
 121
 122         pg_dir = swapper_pg_dir;
 123
 124 #ifdef CONFIG_64BIT
 125         pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERN_REGION_TABLE;
 126         for (i = 0; i < PTRS_PER_PGD; i++)
 127                 pgd_clear_kernel(pg_dir + i);
 128 #else
 129         pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
 130         for (i = 0; i < PTRS_PER_PGD; i++)
 131                 pmd_clear_kernel((pmd_t *)(pg_dir + i));
 132 #endif
 133         vmem_map_init();
 134         setup_ro_region();
 135
 136         S390_lowcore.kernel_asce = pgdir_k;
 137
 138         /* enable virtual mapping in kernel mode */
 139         __ctl_load(pgdir_k, 1, 1);
 140         __ctl_load(pgdir_k, 7, 7);
 141         __ctl_load(pgdir_k, 13, 13);
 142         __raw_local_irq_ssm(ssm_mask);
 143
 144         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 145         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 146         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 147         free_area_init_nodes(max_zone_pfns);
 148 }
 149
 150 void __init mem_init(void)
 151 {
 152         unsigned long codesize, reservedpages, datasize, initsize;
 153
 154         max_mapnr = num_physpages = max_low_pfn;
 155         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 156
 157         /* clear the zero-page */
 158         memset(empty_zero_page, 0, PAGE_SIZE);
 159
 160         /* this will put all low memory onto the freelists */
 161         totalram_pages += free_all_bootmem();
 162
 163         reservedpages = 0;
 164
 165         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 166         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 167         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 168         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 169                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 170                 max_mapnr << (PAGE_SHIFT-10),
 171                 codesize >> 10,
 172                 reservedpages << (PAGE_SHIFT-10),
 173                 datasize >>10,
 174                 initsize >> 10);
 175         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 176                (unsigned long)&__start_rodata,
 177                PFN_ALIGN((unsigned long)&__end_rodata) - 1);
 178 }
 179
 180 void free_initmem(void)
 181 {
 182         unsigned long addr;
 183
 184         addr = (unsigned long)(&__init_begin);
 185         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 186                 ClearPageReserved(virt_to_page(addr));
 187                 init_page_count(virt_to_page(addr));
 188                 memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
 189                 free_page(addr);
 190                 totalram_pages++;
 191         }
 192         printk ("Freeing unused kernel memory: %ldk freed\n",
 193                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 194 }
 195
 196 #ifdef CONFIG_BLK_DEV_INITRD
 197 void free_initrd_mem(unsigned long start, unsigned long end)
 198 {
 199         if (start < end)
 200                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 201         for (; start < end; start += PAGE_SIZE) {
 202                 ClearPageReserved(virt_to_page(start));
 203                 init_page_count(virt_to_page(start));
 204                 free_page(start);
 205                 totalram_pages++;
 206         }
 207 }
 208 #endif