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
  27 #include <asm/processor.h>
  28 #include <asm/system.h>
  29 #include <asm/uaccess.h>
  30 #include <asm/pgtable.h>
  31 #include <asm/pgalloc.h>
  32 #include <asm/dma.h>
  33 #include <asm/lowcore.h>
  34 #include <asm/tlb.h>
  35 #include <asm/tlbflush.h>
  36
  37 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  38
  39 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  40 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
  41
  42 void diag10(unsigned long addr)
  43 {
  44         if (addr >= 0x7ff00000)
  45                 return;
  46 #ifdef CONFIG_64BIT
  47         asm volatile (
  48                 "   sam31\n"
  49                 "   diag %0,%0,0x10\n"
  50                 "0: sam64\n"
  51                 ".section __ex_table,\"a\"\n"
  52                 "   .align 8\n"
  53                 "   .quad 0b, 0b\n"
  54                 ".previous\n"
  55                 : : "a" (addr));
  56 #else
  57         asm volatile (
  58                 "   diag %0,%0,0x10\n"
  59                 "0:\n"
  60                 ".section __ex_table,\"a\"\n"
  61                 "   .align 4\n"
  62                 "   .long 0b, 0b\n"
  63                 ".previous\n"
  64                 : : "a" (addr));
  65 #endif
  66 }
  67
  68 void show_mem(void)
  69 {
  70         int i, total = 0, reserved = 0;
  71         int shared = 0, cached = 0;
  72
  73         printk("Mem-info:\n");
  74         show_free_areas();
  75         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  76         i = max_mapnr;
  77         while (i-- > 0) {
  78                 total++;
  79                 if (PageReserved(mem_map+i))
  80                         reserved++;
  81                 else if (PageSwapCache(mem_map+i))
  82                         cached++;
  83                 else if (page_count(mem_map+i))
  84                         shared += page_count(mem_map+i) - 1;
  85         }
  86         printk("%d pages of RAM\n",total);
  87         printk("%d reserved pages\n",reserved);
  88         printk("%d pages shared\n",shared);
  89         printk("%d pages swap cached\n",cached);
  90 }
  91
  92 /* References to section boundaries */
  93
  94 extern unsigned long _text;
  95 extern unsigned long _etext;
  96 extern unsigned long _edata;
  97 extern unsigned long __bss_start;
  98 extern unsigned long _end;
  99
 100 extern unsigned long __init_begin;
 101 extern unsigned long __init_end;
 102
 103 extern unsigned long __initdata zholes_size[];
 104 /*
 105  * paging_init() sets up the page tables
 106  */
 107
 108 #ifndef CONFIG_64BIT
 109 void __init paging_init(void)
 110 {
 111         pgd_t * pg_dir;
 112         pte_t * pg_table;
 113         pte_t   pte;
 114         int     i;
 115         unsigned long tmp;
 116         unsigned long pfn = 0;
 117         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
 118         static const int ssm_mask = 0x04000000L;
 119
 120         /* unmap whole virtual address space */
 121
 122         pg_dir = swapper_pg_dir;
 123
 124         for (i=0;i<KERNEL_PGD_PTRS;i++)
 125                 pmd_clear((pmd_t*)pg_dir++);
 126
 127         /*
 128          * map whole physical memory to virtual memory (identity mapping)
 129          */
 130
 131         pg_dir = swapper_pg_dir;
 132
 133         while (pfn < max_low_pfn) {
 134                 /*
 135                  * pg_table is physical at this point
 136                  */
 137                 pg_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 138
 139                 pg_dir->pgd0 =  (_PAGE_TABLE | __pa(pg_table));
 140                 pg_dir->pgd1 =  (_PAGE_TABLE | (__pa(pg_table)+1024));
 141                 pg_dir->pgd2 =  (_PAGE_TABLE | (__pa(pg_table)+2048));
 142                 pg_dir->pgd3 =  (_PAGE_TABLE | (__pa(pg_table)+3072));
 143                 pg_dir++;
 144
 145                 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
 146                         pte = pfn_pte(pfn, PAGE_KERNEL);
 147                         if (pfn >= max_low_pfn)
 148                                 pte_clear(&init_mm, 0, &pte);
 149                         set_pte(pg_table, pte);
 150                         pfn++;
 151                 }
 152         }
 153
 154         S390_lowcore.kernel_asce = pgdir_k;
 155
 156         /* enable virtual mapping in kernel mode */
 157         __asm__ __volatile__("    LCTL  1,1,%0\n"
 158                              "    LCTL  7,7,%0\n"
 159                              "    LCTL  13,13,%0\n"
 160                              "    SSM   %1"
 161                              : : "m" (pgdir_k), "m" (ssm_mask));
 162
 163         local_flush_tlb();
 164
 165         {
 166                 unsigned long zones_size[MAX_NR_ZONES];
 167
 168                 memset(zones_size, 0, sizeof(zones_size));
 169                 zones_size[ZONE_DMA] = max_low_pfn;
 170                 free_area_init_node(0, &contig_page_data, zones_size,
 171                                     __pa(PAGE_OFFSET) >> PAGE_SHIFT,
 172                                     zholes_size);
 173         }
 174         return;
 175 }
 176
 177 #else /* CONFIG_64BIT */
 178 void __init paging_init(void)
 179 {
 180         pgd_t * pg_dir;
 181         pmd_t * pm_dir;
 182         pte_t * pt_dir;
 183         pte_t   pte;
 184         int     i,j,k;
 185         unsigned long pfn = 0;
 186         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
 187           _KERN_REGION_TABLE;
 188         static const int ssm_mask = 0x04000000L;
 189
 190         unsigned long zones_size[MAX_NR_ZONES];
 191         unsigned long dma_pfn, high_pfn;
 192
 193         memset(zones_size, 0, sizeof(zones_size));
 194         dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
 195         high_pfn = max_low_pfn;
 196
 197         if (dma_pfn > high_pfn)
 198                 zones_size[ZONE_DMA] = high_pfn;
 199         else {
 200                 zones_size[ZONE_DMA] = dma_pfn;
 201                 zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
 202         }
 203
 204         /* Initialize mem_map[].  */
 205         free_area_init_node(0, &contig_page_data, zones_size,
 206                             __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
 207
 208         /*
 209          * map whole physical memory to virtual memory (identity mapping)
 210          */
 211
 212         pg_dir = swapper_pg_dir;
 213
 214         for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
 215
 216                 if (pfn >= max_low_pfn) {
 217                         pgd_clear(pg_dir);
 218                         continue;
 219                 }
 220
 221                 pm_dir = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE*4);
 222                 pgd_populate(&init_mm, pg_dir, pm_dir);
 223
 224                 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
 225                         if (pfn >= max_low_pfn) {
 226                                 pmd_clear(pm_dir);
 227                                 continue;
 228                         }
 229
 230                         pt_dir = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 231                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
 232
 233                         for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
 234                                 pte = pfn_pte(pfn, PAGE_KERNEL);
 235                                 if (pfn >= max_low_pfn) {
 236                                         pte_clear(&init_mm, 0, &pte);
 237                                         continue;
 238                                 }
 239                                 set_pte(pt_dir, pte);
 240                                 pfn++;
 241                         }
 242                 }
 243         }
 244
 245         S390_lowcore.kernel_asce = pgdir_k;
 246
 247         /* enable virtual mapping in kernel mode */
 248         __asm__ __volatile__("lctlg 1,1,%0\n\t"
 249                              "lctlg 7,7,%0\n\t"
 250                              "lctlg 13,13,%0\n\t"
 251                              "ssm   %1"
 252                              : :"m" (pgdir_k), "m" (ssm_mask));
 253
 254         local_flush_tlb();
 255
 256         return;
 257 }
 258 #endif /* CONFIG_64BIT */
 259
 260 void __init mem_init(void)
 261 {
 262         unsigned long codesize, reservedpages, datasize, initsize;
 263
 264         max_mapnr = num_physpages = max_low_pfn;
 265         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 266
 267         /* clear the zero-page */
 268         memset(empty_zero_page, 0, PAGE_SIZE);
 269
 270         /* this will put all low memory onto the freelists */
 271         totalram_pages += free_all_bootmem();
 272
 273         reservedpages = 0;
 274
 275         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 276         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 277         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 278         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 279                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 280                 max_mapnr << (PAGE_SHIFT-10),
 281                 codesize >> 10,
 282                 reservedpages << (PAGE_SHIFT-10),
 283                 datasize >>10,
 284                 initsize >> 10);
 285 }
 286
 287 void free_initmem(void)
 288 {
 289         unsigned long addr;
 290
 291         addr = (unsigned long)(&__init_begin);
 292         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 293                 ClearPageReserved(virt_to_page(addr));
 294                 init_page_count(virt_to_page(addr));
 295                 free_page(addr);
 296                 totalram_pages++;
 297         }
 298         printk ("Freeing unused kernel memory: %ldk freed\n",
 299                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 300 }
 301
 302 #ifdef CONFIG_BLK_DEV_INITRD
 303 void free_initrd_mem(unsigned long start, unsigned long end)
 304 {
 305         if (start < end)
 306                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 307         for (; start < end; start += PAGE_SIZE) {
 308                 ClearPageReserved(virt_to_page(start));
 309                 init_page_count(virt_to_page(start));
 310                 free_page(start);
 311                 totalram_pages++;
 312         }
 313 }
 314 #endif