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 (
  49                 "   sam31\n"
  50                 "   diag %0,%0,0x10\n"
  51                 "0: sam64\n"
  52                 ".section __ex_table,\"a\"\n"
  53                 "   .align 8\n"
  54                 "   .quad 0b, 0b\n"
  55                 ".previous\n"
  56                 : : "a" (addr));
  57 #else
  58         asm volatile (
  59                 "   diag %0,%0,0x10\n"
  60                 "0:\n"
  61                 ".section __ex_table,\"a\"\n"
  62                 "   .align 4\n"
  63                 "   .long 0b, 0b\n"
  64                 ".previous\n"
  65                 : : "a" (addr));
  66 #endif
  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:       %6ldkB\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 += page_count(mem_map+i) - 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 }
  92
  93 /* References to section boundaries */
  94
  95 extern unsigned long _text;
  96 extern unsigned long _etext;
  97 extern unsigned long _edata;
  98 extern unsigned long __bss_start;
  99 extern unsigned long _end;
 100
 101 extern unsigned long __init_begin;
 102 extern unsigned long __init_end;
 103
 104 /*
 105  * paging_init() sets up the page tables
 106  */
 107
 108 #ifndef CONFIG_ARCH_S390X
 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] = { 0, 0, 0};
 167
 168                 zones_size[ZONE_DMA] = max_low_pfn;
 169                 free_area_init(zones_size);
 170         }
 171         return;
 172 }
 173
 174 #else /* CONFIG_ARCH_S390X */
 175 void __init paging_init(void)
 176 {
 177         pgd_t * pg_dir;
 178         pmd_t * pm_dir;
 179         pte_t * pt_dir;
 180         pte_t   pte;
 181         int     i,j,k;
 182         unsigned long pfn = 0;
 183         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
 184           _KERN_REGION_TABLE;
 185         static const int ssm_mask = 0x04000000L;
 186
 187         unsigned long zones_size[MAX_NR_ZONES] = {0, 0, 0};
 188         unsigned long dma_pfn, high_pfn;
 189
 190         dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
 191         high_pfn = max_low_pfn;
 192
 193         if (dma_pfn > high_pfn)
 194                 zones_size[ZONE_DMA] = high_pfn;
 195         else {
 196                 zones_size[ZONE_DMA] = dma_pfn;
 197                 zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
 198         }
 199
 200         /* Initialize mem_map[].  */
 201         free_area_init(zones_size);
 202
 203
 204         /*
 205          * map whole physical memory to virtual memory (identity mapping)
 206          */
 207
 208         pg_dir = swapper_pg_dir;
 209
 210         for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
 211
 212                 if (pfn >= max_low_pfn) {
 213                         pgd_clear(pg_dir);
 214                         continue;
 215                 }
 216
 217                 pm_dir = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE*4);
 218                 pgd_populate(&init_mm, pg_dir, pm_dir);
 219
 220                 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
 221                         if (pfn >= max_low_pfn) {
 222                                 pmd_clear(pm_dir);
 223                                 continue;
 224                         }
 225
 226                         pt_dir = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 227                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
 228
 229                         for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
 230                                 pte = pfn_pte(pfn, PAGE_KERNEL);
 231                                 if (pfn >= max_low_pfn) {
 232                                         pte_clear(&init_mm, 0, &pte);
 233                                         continue;
 234                                 }
 235                                 set_pte(pt_dir, pte);
 236                                 pfn++;
 237                         }
 238                 }
 239         }
 240
 241         S390_lowcore.kernel_asce = pgdir_k;
 242
 243         /* enable virtual mapping in kernel mode */
 244         __asm__ __volatile__("lctlg 1,1,%0\n\t"
 245                              "lctlg 7,7,%0\n\t"
 246                              "lctlg 13,13,%0\n\t"
 247                              "ssm   %1"
 248                              : :"m" (pgdir_k), "m" (ssm_mask));
 249
 250         local_flush_tlb();
 251
 252         return;
 253 }
 254 #endif /* CONFIG_ARCH_S390X */
 255
 256 void __init mem_init(void)
 257 {
 258         unsigned long codesize, reservedpages, datasize, initsize;
 259
 260         max_mapnr = num_physpages = max_low_pfn;
 261         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 262
 263         /* clear the zero-page */
 264         memset(empty_zero_page, 0, PAGE_SIZE);
 265
 266         /* this will put all low memory onto the freelists */
 267         totalram_pages += free_all_bootmem();
 268
 269         reservedpages = 0;
 270
 271         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 272         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 273         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 274         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 275                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 276                 max_mapnr << (PAGE_SHIFT-10),
 277                 codesize >> 10,
 278                 reservedpages << (PAGE_SHIFT-10),
 279                 datasize >>10,
 280                 initsize >> 10);
 281 }
 282
 283 void free_initmem(void)
 284 {
 285         unsigned long addr;
 286
 287         addr = (unsigned long)(&__init_begin);
 288         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 289                 ClearPageReserved(virt_to_page(addr));
 290                 set_page_count(virt_to_page(addr), 1);
 291                 free_page(addr);
 292                 totalram_pages++;
 293         }
 294         printk ("Freeing unused kernel memory: %ldk freed\n",
 295                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 296 }
 297
 298 #ifdef CONFIG_BLK_DEV_INITRD
 299 void free_initrd_mem(unsigned long start, unsigned long end)
 300 {
 301         if (start < end)
 302                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 303         for (; start < end; start += PAGE_SIZE) {
 304                 ClearPageReserved(virt_to_page(start));
 305                 set_page_count(virt_to_page(start), 1);
 306                 free_page(start);
 307                 totalram_pages++;
 308         }
 309 }
 310 #endif