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/config.h>
  13 #include <linux/signal.h>
  14 #include <linux/sched.h>
  15 #include <linux/kernel.h>
  16 #include <linux/errno.h>
  17 #include <linux/string.h>
  18 #include <linux/types.h>
  19 #include <linux/ptrace.h>
  20 #include <linux/mman.h>
  21 #include <linux/mm.h>
  22 #include <linux/swap.h>
  23 #include <linux/smp.h>
  24 #include <linux/init.h>
  25 #ifdef CONFIG_BLK_DEV_INITRD
  26 #include <linux/blk.h>
  27 #endif
  28 #include <linux/pagemap.h>
  29 #include <linux/bootmem.h>
  30
  31 #include <asm/processor.h>
  32 #include <asm/system.h>
  33 #include <asm/uaccess.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/pgalloc.h>
  36 #include <asm/dma.h>
  37 #include <asm/lowcore.h>
  38 #include <asm/tlb.h>
  39
  40 mmu_gather_t mmu_gathers[NR_CPUS];
  41
  42 static unsigned long totalram_pages;
  43
  44 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  45 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
  46
  47 int do_check_pgt_cache(int low, int high)
  48 {
  49         int freed = 0;
  50         if(pgtable_cache_size > high) {
  51                 do {
  52                         if(pgd_quicklist) {
  53                                 free_pgd_slow(get_pgd_fast());
  54                                 freed += 2;
  55                         }
  56                         if(pmd_quicklist) {
  57                                 pmd_free_slow(pmd_alloc_one_fast(NULL, 0));
  58                                 freed++;
  59                         }
  60                         if(pte_quicklist) {
  61                                 pte_free_slow(pte_alloc_one_fast(NULL, 0));
  62                                 freed++;
  63                         }
  64                 } while(pgtable_cache_size > low);
  65         }
  66         return freed;
  67 }
  68
  69 void show_mem(void)
  70 {
  71         int i, total = 0, reserved = 0;
  72         int shared = 0, cached = 0;
  73
  74         printk("Mem-info:\n");
  75         show_free_areas();
  76         printk("Free swap:       %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
  77         i = max_mapnr;
  78         while (i-- > 0) {
  79                 total++;
  80                 if (PageReserved(mem_map+i))
  81                         reserved++;
  82                 else if (PageSwapCache(mem_map+i))
  83                         cached++;
  84                 else if (page_count(mem_map+i))
  85                         shared += atomic_read(&mem_map[i].count) - 1;
  86         }
  87         printk("%d pages of RAM\n",total);
  88         printk("%d reserved pages\n",reserved);
  89         printk("%d pages shared\n",shared);
  90         printk("%d pages swap cached\n",cached);
  91         printk("%ld pages in page table cache\n",pgtable_cache_size);
  92         show_buffers();
  93 }
  94
  95 /* References to section boundaries */
  96
  97 extern unsigned long _text;
  98 extern unsigned long _etext;
  99 extern unsigned long _edata;
 100 extern unsigned long __bss_start;
 101 extern unsigned long _end;
 102
 103 extern unsigned long __init_begin;
 104 extern unsigned long __init_end;
 105
 106 /*
 107  * paging_init() sets up the page tables - note that the first 4MB are
 108  * already mapped by head.S.
 109  * paging_init will erase this initial mapping
 110  */
 111
 112 unsigned long last_valid_pfn;
 113
 114 void __init paging_init(void)
 115 {
 116         pgd_t * pg_dir;
 117         pte_t * pg_table;
 118         pte_t   pte;
 119         int     i;
 120         unsigned long tmp;
 121         unsigned long address=0;
 122         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
 123         unsigned long end_mem = (unsigned long) __va(max_low_pfn*PAGE_SIZE);
 124         static const int ssm_mask = 0x04000000L;
 125
 126         /* unmap whole virtual address space */
 127
 128         pg_dir = swapper_pg_dir;
 129
 130         for (i=0;i<KERNEL_PGD_PTRS;i++)
 131                 pmd_clear((pmd_t*)pg_dir++);
 132
 133         /*
 134          * map whole physical memory to virtual memory (identity mapping)
 135          */
 136
 137         pg_dir = swapper_pg_dir;
 138
 139         while (address < end_mem) {
 140                 /*
 141                  * pg_table is physical at this point
 142                  */
 143                 pg_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 144
 145                 pg_dir->pgd0 =  (_PAGE_TABLE | __pa(pg_table));
 146                 pg_dir->pgd1 =  (_PAGE_TABLE | (__pa(pg_table)+1024));
 147                 pg_dir->pgd2 =  (_PAGE_TABLE | (__pa(pg_table)+2048));
 148                 pg_dir->pgd3 =  (_PAGE_TABLE | (__pa(pg_table)+3072));
 149                 pg_dir++;
 150
 151                 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
 152                         pte = mk_pte_phys(address, PAGE_KERNEL);
 153                         if (address >= end_mem)
 154                                 pte_clear(&pte);
 155                         set_pte(pg_table, pte);
 156                         address += PAGE_SIZE;
 157                 }
 158         }
 159
 160         /* enable virtual mapping in kernel mode */
 161         __asm__ __volatile__("    LCTL  1,1,%0\n"
 162                              "    LCTL  7,7,%0\n"
 163                              "    LCTL  13,13,%0\n"
 164                              "    SSM   %1"
 165                              : : "m" (pgdir_k), "m" (ssm_mask));
 166
 167         local_flush_tlb();
 168
 169         {
 170                 unsigned long zones_size[MAX_NR_ZONES] = { 0, 0, 0};
 171
 172                 zones_size[ZONE_DMA] = max_low_pfn;
 173                 free_area_init(zones_size);
 174         }
 175
 176         return;
 177 }
 178
 179 void __init mem_init(void)
 180 {
 181         int codesize, reservedpages, datasize, initsize;
 182
 183         max_mapnr = num_physpages = max_low_pfn;
 184         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 185
 186         /* clear the zero-page */
 187         memset(empty_zero_page, 0, PAGE_SIZE);
 188
 189         /* this will put all low memory onto the freelists */
 190         totalram_pages += free_all_bootmem();
 191
 192         reservedpages = 0;
 193
 194         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 195         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 196         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 197         printk("Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init)\n",
 198                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 199                 max_mapnr << (PAGE_SHIFT-10),
 200                 codesize >> 10,
 201                 reservedpages << (PAGE_SHIFT-10),
 202                 datasize >>10,
 203                 initsize >> 10);
 204 }
 205
 206 void free_initmem(void)
 207 {
 208         unsigned long addr;
 209
 210         addr = (unsigned long)(&__init_begin);
 211         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 212                 ClearPageReserved(virt_to_page(addr));
 213                 set_page_count(virt_to_page(addr), 1);
 214                 free_page(addr);
 215                 totalram_pages++;
 216         }
 217         printk (KERN_INFO "Freeing unused kernel memory: %dk freed\n",
 218                 (&__init_end - &__init_begin) >> 10);
 219 }
 220
 221 #ifdef CONFIG_BLK_DEV_INITRD
 222 void free_initrd_mem(unsigned long start, unsigned long end)
 223 {
 224         if (start < end)
 225                 printk (KERN_INFO "Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 226         for (; start < end; start += PAGE_SIZE) {
 227                 ClearPageReserved(virt_to_page(start));
 228                 set_page_count(virt_to_page(start), 1);
 229                 free_page(start);
 230                 totalram_pages++;
 231         }
 232 }
 233 #endif
 234
 235 void si_meminfo(struct sysinfo *val)
 236 {
 237         val->totalram = totalram_pages;
 238         val->sharedram = 0;
 239         val->freeram = nr_free_pages();
 240         val->bufferram = atomic_read(&buffermem_pages);
 241         val->totalhigh = 0;
 242         val->freehigh = 0;
 243         val->mem_unit = PAGE_SIZE;
 244 }