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 #include <linux/pagemap.h>
  26 #include <linux/bootmem.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
  38 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  39
  40 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  41 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
  42
  43 void diag10(unsigned long addr)
  44 {
  45         if (addr >= 0x7ff00000)
  46                 return;
  47 #ifdef __s390x__
  48         asm volatile ("sam31\n\t"
  49                       "diag %0,%0,0x10\n\t"
  50                       "sam64" : : "a" (addr) );
  51 #else
  52         asm volatile ("diag %0,%0,0x10" : : "a" (addr) );
  53 #endif
  54 }
  55
  56 void show_mem(void)
  57 {
  58         int i, total = 0, reserved = 0;
  59         int shared = 0, cached = 0;
  60
  61         printk("Mem-info:\n");
  62         show_free_areas();
  63         printk("Free swap:       %6dkB\n",nr_swap_pages<<(PAGE_SHIFT-10));
  64         i = max_mapnr;
  65         while (i-- > 0) {
  66                 total++;
  67                 if (PageReserved(mem_map+i))
  68                         reserved++;
  69                 else if (PageSwapCache(mem_map+i))
  70                         cached++;
  71                 else if (page_count(mem_map+i))
  72                         shared += page_count(mem_map+i) - 1;
  73         }
  74         printk("%d pages of RAM\n",total);
  75         printk("%d reserved pages\n",reserved);
  76         printk("%d pages shared\n",shared);
  77         printk("%d pages swap cached\n",cached);
  78 }
  79
  80 /* References to section boundaries */
  81
  82 extern unsigned long _text;
  83 extern unsigned long _etext;
  84 extern unsigned long _edata;
  85 extern unsigned long __bss_start;
  86 extern unsigned long _end;
  87
  88 extern unsigned long __init_begin;
  89 extern unsigned long __init_end;
  90
  91 /*
  92  * paging_init() sets up the page tables
  93  */
  94
  95 #ifndef CONFIG_ARCH_S390X
  96 void __init paging_init(void)
  97 {
  98         pgd_t * pg_dir;
  99         pte_t * pg_table;
 100         pte_t   pte;
 101         int     i;
 102         unsigned long tmp;
 103         unsigned long pfn = 0;
 104         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
 105         static const int ssm_mask = 0x04000000L;
 106
 107         /* unmap whole virtual address space */
 108
 109         pg_dir = swapper_pg_dir;
 110
 111         for (i=0;i<KERNEL_PGD_PTRS;i++)
 112                 pmd_clear((pmd_t*)pg_dir++);
 113
 114         /*
 115          * map whole physical memory to virtual memory (identity mapping)
 116          */
 117
 118         pg_dir = swapper_pg_dir;
 119
 120         while (pfn < max_low_pfn) {
 121                 /*
 122                  * pg_table is physical at this point
 123                  */
 124                 pg_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 125
 126                 pg_dir->pgd0 =  (_PAGE_TABLE | __pa(pg_table));
 127                 pg_dir->pgd1 =  (_PAGE_TABLE | (__pa(pg_table)+1024));
 128                 pg_dir->pgd2 =  (_PAGE_TABLE | (__pa(pg_table)+2048));
 129                 pg_dir->pgd3 =  (_PAGE_TABLE | (__pa(pg_table)+3072));
 130                 pg_dir++;
 131
 132                 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
 133                         pte = pfn_pte(pfn, PAGE_KERNEL);
 134                         if (pfn >= max_low_pfn)
 135                                 pte_clear(&pte);
 136                         set_pte(pg_table, pte);
 137                         pfn++;
 138                 }
 139         }
 140
 141         S390_lowcore.kernel_asce = pgdir_k;
 142
 143         /* enable virtual mapping in kernel mode */
 144         __asm__ __volatile__("    LCTL  1,1,%0\n"
 145                              "    LCTL  7,7,%0\n"
 146                              "    LCTL  13,13,%0\n"
 147                              "    SSM   %1"
 148                              : : "m" (pgdir_k), "m" (ssm_mask));
 149
 150         local_flush_tlb();
 151
 152         {
 153                 unsigned long zones_size[MAX_NR_ZONES] = { 0, 0, 0};
 154
 155                 zones_size[ZONE_DMA] = max_low_pfn;
 156                 free_area_init(zones_size);
 157         }
 158         return;
 159 }
 160
 161 #else /* CONFIG_ARCH_S390X */
 162 void __init paging_init(void)
 163 {
 164         pgd_t * pg_dir;
 165         pmd_t * pm_dir;
 166         pte_t * pt_dir;
 167         pte_t   pte;
 168         int     i,j,k;
 169         unsigned long pfn = 0;
 170         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
 171           _KERN_REGION_TABLE;
 172         static const int ssm_mask = 0x04000000L;
 173
 174         unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
 175         unsigned long dma_pfn, high_pfn;
 176
 177         dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
 178         high_pfn = max_low_pfn;
 179
 180         if (dma_pfn > high_pfn)
 181                 zones_size[ZONE_DMA] = high_pfn;
 182         else {
 183                 zones_size[ZONE_DMA] = dma_pfn;
 184                 zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
 185         }
 186
 187         /* Initialize mem_map[].  */
 188         free_area_init(zones_size);
 189
 190
 191         /*
 192          * map whole physical memory to virtual memory (identity mapping)
 193          */
 194
 195         pg_dir = swapper_pg_dir;
 196
 197         for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
 198
 199                 if (pfn >= max_low_pfn) {
 200                         pgd_clear(pg_dir);
 201                         continue;
 202                 }
 203
 204                 pm_dir = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE*4);
 205                 pgd_populate(&init_mm, pg_dir, pm_dir);
 206
 207                 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
 208                         if (pfn >= max_low_pfn) {
 209                                 pmd_clear(pm_dir);
 210                                 continue;
 211                         }
 212
 213                         pt_dir = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 214                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
 215
 216                         for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
 217                                 pte = pfn_pte(pfn, PAGE_KERNEL);
 218                                 if (pfn >= max_low_pfn) {
 219                                         pte_clear(&pte);
 220                                         continue;
 221                                 }
 222                                 set_pte(pt_dir, pte);
 223                                 pfn++;
 224                         }
 225                 }
 226         }
 227
 228         S390_lowcore.kernel_asce = pgdir_k;
 229
 230         /* enable virtual mapping in kernel mode */
 231         __asm__ __volatile__("lctlg 1,1,%0\n\t"
 232                              "lctlg 7,7,%0\n\t"
 233                              "lctlg 13,13,%0\n\t"
 234                              "ssm   %1"
 235                              : :"m" (pgdir_k), "m" (ssm_mask));
 236
 237         local_flush_tlb();
 238
 239         return;
 240 }
 241 #endif /* CONFIG_ARCH_S390X */
 242
 243 void __init mem_init(void)
 244 {
 245         unsigned long codesize, reservedpages, datasize, initsize;
 246
 247         max_mapnr = num_physpages = max_low_pfn;
 248         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 249
 250         /* clear the zero-page */
 251         memset(empty_zero_page, 0, PAGE_SIZE);
 252
 253         /* this will put all low memory onto the freelists */
 254         totalram_pages += free_all_bootmem();
 255
 256         reservedpages = 0;
 257
 258         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 259         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 260         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 261         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 262                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 263                 max_mapnr << (PAGE_SHIFT-10),
 264                 codesize >> 10,
 265                 reservedpages << (PAGE_SHIFT-10),
 266                 datasize >>10,
 267                 initsize >> 10);
 268 }
 269
 270 void free_initmem(void)
 271 {
 272         unsigned long addr;
 273
 274         addr = (unsigned long)(&__init_begin);
 275         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 276                 ClearPageReserved(virt_to_page(addr));
 277                 set_page_count(virt_to_page(addr), 1);
 278                 free_page(addr);
 279                 totalram_pages++;
 280         }
 281         printk ("Freeing unused kernel memory: %ldk freed\n",
 282                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 283 }
 284
 285 #ifdef CONFIG_BLK_DEV_INITRD
 286 void free_initrd_mem(unsigned long start, unsigned long end)
 287 {
 288         if (start < end)
 289                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 290         for (; start < end; start += PAGE_SIZE) {
 291                 ClearPageReserved(virt_to_page(start));
 292                 set_page_count(virt_to_page(start), 1);
 293                 free_page(start);
 294                 totalram_pages++;
 295         }
 296 }
 297 #endif