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 extern unsigned long __initdata zholes_size[];
 105 /*
 106  * paging_init() sets up the page tables
 107  */
 108
 109 #ifndef CONFIG_ARCH_S390X
 110 void __init paging_init(void)
 111 {
 112         pgd_t * pg_dir;
 113         pte_t * pg_table;
 114         pte_t   pte;
 115         int     i;
 116         unsigned long tmp;
 117         unsigned long pfn = 0;
 118         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
 119         static const int ssm_mask = 0x04000000L;
 120
 121         /* unmap whole virtual address space */
 122
 123         pg_dir = swapper_pg_dir;
 124
 125         for (i=0;i<KERNEL_PGD_PTRS;i++)
 126                 pmd_clear((pmd_t*)pg_dir++);
 127
 128         /*
 129          * map whole physical memory to virtual memory (identity mapping)
 130          */
 131
 132         pg_dir = swapper_pg_dir;
 133
 134         while (pfn < max_low_pfn) {
 135                 /*
 136                  * pg_table is physical at this point
 137                  */
 138                 pg_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 139
 140                 pg_dir->pgd0 =  (_PAGE_TABLE | __pa(pg_table));
 141                 pg_dir->pgd1 =  (_PAGE_TABLE | (__pa(pg_table)+1024));
 142                 pg_dir->pgd2 =  (_PAGE_TABLE | (__pa(pg_table)+2048));
 143                 pg_dir->pgd3 =  (_PAGE_TABLE | (__pa(pg_table)+3072));
 144                 pg_dir++;
 145
 146                 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
 147                         pte = pfn_pte(pfn, PAGE_KERNEL);
 148                         if (pfn >= max_low_pfn)
 149                                 pte_clear(&init_mm, 0, &pte);
 150                         set_pte(pg_table, pte);
 151                         pfn++;
 152                 }
 153         }
 154
 155         S390_lowcore.kernel_asce = pgdir_k;
 156
 157         /* enable virtual mapping in kernel mode */
 158         __asm__ __volatile__("    LCTL  1,1,%0\n"
 159                              "    LCTL  7,7,%0\n"
 160                              "    LCTL  13,13,%0\n"
 161                              "    SSM   %1"
 162                              : : "m" (pgdir_k), "m" (ssm_mask));
 163
 164         local_flush_tlb();
 165
 166         {
 167                 unsigned long zones_size[MAX_NR_ZONES];
 168
 169                 memset(zones_size, 0, sizeof(zones_size));
 170                 zones_size[ZONE_DMA] = max_low_pfn;
 171                 free_area_init_node(0, &contig_page_data, zones_size,
 172                                     __pa(PAGE_OFFSET) >> PAGE_SHIFT,
 173                                     zholes_size);
 174         }
 175         return;
 176 }
 177
 178 #else /* CONFIG_ARCH_S390X */
 179 void __init paging_init(void)
 180 {
 181         pgd_t * pg_dir;
 182         pmd_t * pm_dir;
 183         pte_t * pt_dir;
 184         pte_t   pte;
 185         int     i,j,k;
 186         unsigned long pfn = 0;
 187         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
 188           _KERN_REGION_TABLE;
 189         static const int ssm_mask = 0x04000000L;
 190
 191         unsigned long zones_size[MAX_NR_ZONES];
 192         unsigned long dma_pfn, high_pfn;
 193
 194         memset(zones_size, 0, sizeof(zones_size));
 195         dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
 196         high_pfn = max_low_pfn;
 197
 198         if (dma_pfn > high_pfn)
 199                 zones_size[ZONE_DMA] = high_pfn;
 200         else {
 201                 zones_size[ZONE_DMA] = dma_pfn;
 202                 zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
 203         }
 204
 205         /* Initialize mem_map[].  */
 206         free_area_init_node(0, &contig_page_data, zones_size,
 207                             __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
 208
 209         /*
 210          * map whole physical memory to virtual memory (identity mapping)
 211          */
 212
 213         pg_dir = swapper_pg_dir;
 214
 215         for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
 216
 217                 if (pfn >= max_low_pfn) {
 218                         pgd_clear(pg_dir);
 219                         continue;
 220                 }
 221
 222                 pm_dir = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE*4);
 223                 pgd_populate(&init_mm, pg_dir, pm_dir);
 224
 225                 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
 226                         if (pfn >= max_low_pfn) {
 227                                 pmd_clear(pm_dir);
 228                                 continue;
 229                         }
 230
 231                         pt_dir = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
 232                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
 233
 234                         for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
 235                                 pte = pfn_pte(pfn, PAGE_KERNEL);
 236                                 if (pfn >= max_low_pfn) {
 237                                         pte_clear(&init_mm, 0, &pte);
 238                                         continue;
 239                                 }
 240                                 set_pte(pt_dir, pte);
 241                                 pfn++;
 242                         }
 243                 }
 244         }
 245
 246         S390_lowcore.kernel_asce = pgdir_k;
 247
 248         /* enable virtual mapping in kernel mode */
 249         __asm__ __volatile__("lctlg 1,1,%0\n\t"
 250                              "lctlg 7,7,%0\n\t"
 251                              "lctlg 13,13,%0\n\t"
 252                              "ssm   %1"
 253                              : :"m" (pgdir_k), "m" (ssm_mask));
 254
 255         local_flush_tlb();
 256
 257         return;
 258 }
 259 #endif /* CONFIG_ARCH_S390X */
 260
 261 void __init mem_init(void)
 262 {
 263         unsigned long codesize, reservedpages, datasize, initsize;
 264
 265         max_mapnr = num_physpages = max_low_pfn;
 266         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 267
 268         /* clear the zero-page */
 269         memset(empty_zero_page, 0, PAGE_SIZE);
 270
 271         /* this will put all low memory onto the freelists */
 272         totalram_pages += free_all_bootmem();
 273
 274         reservedpages = 0;
 275
 276         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 277         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 278         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 279         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 280                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 281                 max_mapnr << (PAGE_SHIFT-10),
 282                 codesize >> 10,
 283                 reservedpages << (PAGE_SHIFT-10),
 284                 datasize >>10,
 285                 initsize >> 10);
 286 }
 287
 288 void free_initmem(void)
 289 {
 290         unsigned long addr;
 291
 292         addr = (unsigned long)(&__init_begin);
 293         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 294                 ClearPageReserved(virt_to_page(addr));
 295                 set_page_count(virt_to_page(addr), 1);
 296                 free_page(addr);
 297                 totalram_pages++;
 298         }
 299         printk ("Freeing unused kernel memory: %ldk freed\n",
 300                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 301 }
 302
 303 #ifdef CONFIG_BLK_DEV_INITRD
 304 void free_initrd_mem(unsigned long start, unsigned long end)
 305 {
 306         if (start < end)
 307                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 308         for (; start < end; start += PAGE_SIZE) {
 309                 ClearPageReserved(virt_to_page(start));
 310                 set_page_count(virt_to_page(start), 1);
 311                 free_page(start);
 312                 totalram_pages++;
 313         }
 314 }
 315 #endif