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
  28 #include <asm/processor.h>
  29 #include <asm/system.h>
  30 #include <asm/uaccess.h>
  31 #include <asm/pgtable.h>
  32 #include <asm/pgalloc.h>
  33 #include <asm/dma.h>
  34 #include <asm/lowcore.h>
  35 #include <asm/tlb.h>
  36 #include <asm/tlbflush.h>
  37 #include <asm/sections.h>
  38
  39 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  40
  41 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  42 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
  43
  44 void diag10(unsigned long addr)
  45 {
  46         if (addr >= 0x7ff00000)
  47                 return;
  48         asm volatile(
  49 #ifdef CONFIG_64BIT
  50                 "       sam31\n"
  51                 "       diag    %0,%0,0x10\n"
  52                 "0:     sam64\n"
  53 #else
  54                 "       diag    %0,%0,0x10\n"
  55                 "0:\n"
  56 #endif
  57                 EX_TABLE(0b,0b)
  58                 : : "a" (addr));
  59 }
  60
  61 void show_mem(void)
  62 {
  63         int i, total = 0, reserved = 0;
  64         int shared = 0, cached = 0;
  65         struct page *page;
  66
  67         printk("Mem-info:\n");
  68         show_free_areas();
  69         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  70         i = max_mapnr;
  71         while (i-- > 0) {
  72                 if (!pfn_valid(i))
  73                         continue;
  74                 page = pfn_to_page(i);
  75                 total++;
  76                 if (PageReserved(page))
  77                         reserved++;
  78                 else if (PageSwapCache(page))
  79                         cached++;
  80                 else if (page_count(page))
  81                         shared += page_count(page) - 1;
  82         }
  83         printk("%d pages of RAM\n",total);
  84         printk("%d reserved pages\n",reserved);
  85         printk("%d pages shared\n",shared);
  86         printk("%d pages swap cached\n",cached);
  87 }
  88
  89 static void __init setup_ro_region(void)
  90 {
  91         pgd_t *pgd;
  92         pmd_t *pmd;
  93         pte_t *pte;
  94         pte_t new_pte;
  95         unsigned long address, end;
  96
  97         address = ((unsigned long)&__start_rodata) & PAGE_MASK;
  98         end = PFN_ALIGN((unsigned long)&__end_rodata);
  99
 100         for (; address < end; address += PAGE_SIZE) {
 101                 pgd = pgd_offset_k(address);
 102                 pmd = pmd_offset(pgd, address);
 103                 pte = pte_offset_kernel(pmd, address);
 104                 new_pte = mk_pte_phys(address, __pgprot(_PAGE_RO));
 105                 set_pte(pte, new_pte);
 106         }
 107 }
 108
 109 extern unsigned long __initdata zholes_size[];
 110 extern void vmem_map_init(void);
 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 zones_size[MAX_NR_ZONES];
 121         unsigned long dma_pfn, high_pfn;
 122
 123         pg_dir = swapper_pg_dir;
 124
 125 #ifdef CONFIG_64BIT
 126         pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERN_REGION_TABLE;
 127         for (i = 0; i < PTRS_PER_PGD; i++)
 128                 pgd_clear(pg_dir + i);
 129 #else
 130         pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
 131         for (i = 0; i < PTRS_PER_PGD; i++)
 132                 pmd_clear((pmd_t *)(pg_dir + i));
 133 #endif
 134         vmem_map_init();
 135         setup_ro_region();
 136
 137         S390_lowcore.kernel_asce = pgdir_k;
 138
 139         /* enable virtual mapping in kernel mode */
 140         __ctl_load(pgdir_k, 1, 1);
 141         __ctl_load(pgdir_k, 7, 7);
 142         __ctl_load(pgdir_k, 13, 13);
 143         __raw_local_irq_ssm(ssm_mask);
 144
 145         memset(zones_size, 0, sizeof(zones_size));
 146         dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
 147         high_pfn = max_low_pfn;
 148
 149         if (dma_pfn > high_pfn)
 150                 zones_size[ZONE_DMA] = high_pfn;
 151         else {
 152                 zones_size[ZONE_DMA] = dma_pfn;
 153                 zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
 154         }
 155
 156         /* Initialize mem_map[].  */
 157         free_area_init_node(0, &contig_page_data, zones_size,
 158                             __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
 159 }
 160
 161 void __init mem_init(void)
 162 {
 163         unsigned long codesize, reservedpages, datasize, initsize;
 164
 165         max_mapnr = num_physpages = max_low_pfn;
 166         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 167
 168         /* clear the zero-page */
 169         memset(empty_zero_page, 0, PAGE_SIZE);
 170
 171         /* this will put all low memory onto the freelists */
 172         totalram_pages += free_all_bootmem();
 173
 174         reservedpages = 0;
 175
 176         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 177         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 178         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 179         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 180                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 181                 max_mapnr << (PAGE_SHIFT-10),
 182                 codesize >> 10,
 183                 reservedpages << (PAGE_SHIFT-10),
 184                 datasize >>10,
 185                 initsize >> 10);
 186         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 187                (unsigned long)&__start_rodata,
 188                PFN_ALIGN((unsigned long)&__end_rodata) - 1);
 189         printk("Virtual memmap size: %ldk\n",
 190                (max_pfn * sizeof(struct page)) >> 10);
 191 }
 192
 193 void free_initmem(void)
 194 {
 195         unsigned long addr;
 196
 197         addr = (unsigned long)(&__init_begin);
 198         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 199                 ClearPageReserved(virt_to_page(addr));
 200                 init_page_count(virt_to_page(addr));
 201                 free_page(addr);
 202                 totalram_pages++;
 203         }
 204         printk ("Freeing unused kernel memory: %ldk freed\n",
 205                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 206 }
 207
 208 #ifdef CONFIG_BLK_DEV_INITRD
 209 void free_initrd_mem(unsigned long start, unsigned long end)
 210 {
 211         if (start < end)
 212                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 213         for (; start < end; start += PAGE_SIZE) {
 214                 ClearPageReserved(virt_to_page(start));
 215                 init_page_count(virt_to_page(start));
 216                 free_page(start);
 217                 totalram_pages++;
 218         }
 219 }
 220 #endif