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 #include <linux/pfn.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 #include <asm/sections.h>
  38
  39 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  40
  41 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  42 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
  43
  44 void diag10(unsigned long addr)
  45 {
  46         if (addr >= 0x7ff00000)
  47                 return;
  48 #ifdef CONFIG_64BIT
  49         asm volatile (
  50                 "   sam31\n"
  51                 "   diag %0,%0,0x10\n"
  52                 "0: sam64\n"
  53                 ".section __ex_table,\"a\"\n"
  54                 "   .align 8\n"
  55                 "   .quad 0b, 0b\n"
  56                 ".previous\n"
  57                 : : "a" (addr));
  58 #else
  59         asm volatile (
  60                 "   diag %0,%0,0x10\n"
  61                 "0:\n"
  62                 ".section __ex_table,\"a\"\n"
  63                 "   .align 4\n"
  64                 "   .long 0b, 0b\n"
  65                 ".previous\n"
  66                 : : "a" (addr));
  67 #endif
  68 }
  69
  70 void show_mem(void)
  71 {
  72         int i, total = 0, reserved = 0;
  73         int shared = 0, cached = 0;
  74
  75         printk("Mem-info:\n");
  76         show_free_areas();
  77         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  78         i = max_mapnr;
  79         while (i-- > 0) {
  80                 total++;
  81                 if (PageReserved(mem_map+i))
  82                         reserved++;
  83                 else if (PageSwapCache(mem_map+i))
  84                         cached++;
  85                 else if (page_count(mem_map+i))
  86                         shared += page_count(mem_map+i) - 1;
  87         }
  88         printk("%d pages of RAM\n",total);
  89         printk("%d reserved pages\n",reserved);
  90         printk("%d pages shared\n",shared);
  91         printk("%d pages swap cached\n",cached);
  92 }
  93
  94 extern unsigned long __initdata zholes_size[];
  95 /*
  96  * paging_init() sets up the page tables
  97  */
  98
  99 #ifndef CONFIG_64BIT
 100 void __init paging_init(void)
 101 {
 102         pgd_t * pg_dir;
 103         pte_t * pg_table;
 104         pte_t   pte;
 105         int     i;
 106         unsigned long tmp;
 107         unsigned long pfn = 0;
 108         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
 109         static const int ssm_mask = 0x04000000L;
 110         unsigned long ro_start_pfn, ro_end_pfn;
 111
 112         ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
 113         ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
 114
 115         /* unmap whole virtual address space */
 116
 117         pg_dir = swapper_pg_dir;
 118
 119         for (i=0;i<KERNEL_PGD_PTRS;i++)
 120                 pmd_clear((pmd_t*)pg_dir++);
 121
 122         /*
 123          * map whole physical memory to virtual memory (identity mapping)
 124          */
 125
 126         pg_dir = swapper_pg_dir;
 127
 128         while (pfn < max_low_pfn) {
 129                 /*
 130                  * pg_table is physical at this point
 131                  */
 132                 pg_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
 133
 134                 pg_dir->pgd0 =  (_PAGE_TABLE | __pa(pg_table));
 135                 pg_dir->pgd1 =  (_PAGE_TABLE | (__pa(pg_table)+1024));
 136                 pg_dir->pgd2 =  (_PAGE_TABLE | (__pa(pg_table)+2048));
 137                 pg_dir->pgd3 =  (_PAGE_TABLE | (__pa(pg_table)+3072));
 138                 pg_dir++;
 139
 140                 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
 141                         if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
 142                                 pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
 143                         else
 144                                 pte = pfn_pte(pfn, PAGE_KERNEL);
 145                         if (pfn >= max_low_pfn)
 146                                 pte_clear(&init_mm, 0, &pte);
 147                         set_pte(pg_table, pte);
 148                         pfn++;
 149                 }
 150         }
 151
 152         S390_lowcore.kernel_asce = pgdir_k;
 153
 154         /* enable virtual mapping in kernel mode */
 155         __asm__ __volatile__("    LCTL  1,1,%0\n"
 156                              "    LCTL  7,7,%0\n"
 157                              "    LCTL  13,13,%0\n"
 158                              "    SSM   %1"
 159                              : : "m" (pgdir_k), "m" (ssm_mask));
 160
 161         local_flush_tlb();
 162
 163         {
 164                 unsigned long zones_size[MAX_NR_ZONES];
 165
 166                 memset(zones_size, 0, sizeof(zones_size));
 167                 zones_size[ZONE_DMA] = max_low_pfn;
 168                 free_area_init_node(0, &contig_page_data, zones_size,
 169                                     __pa(PAGE_OFFSET) >> PAGE_SHIFT,
 170                                     zholes_size);
 171         }
 172         return;
 173 }
 174
 175 #else /* CONFIG_64BIT */
 176
 177 void __init paging_init(void)
 178 {
 179         pgd_t * pg_dir;
 180         pmd_t * pm_dir;
 181         pte_t * pt_dir;
 182         pte_t   pte;
 183         int     i,j,k;
 184         unsigned long pfn = 0;
 185         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
 186           _KERN_REGION_TABLE;
 187         static const int ssm_mask = 0x04000000L;
 188         unsigned long zones_size[MAX_NR_ZONES];
 189         unsigned long dma_pfn, high_pfn;
 190         unsigned long ro_start_pfn, ro_end_pfn;
 191
 192         memset(zones_size, 0, sizeof(zones_size));
 193         dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
 194         high_pfn = max_low_pfn;
 195         ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
 196         ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
 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_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_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                                 if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
 236                                         pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
 237                                 else
 238                                         pte = pfn_pte(pfn, PAGE_KERNEL);
 239                                 if (pfn >= max_low_pfn) {
 240                                         pte_clear(&init_mm, 0, &pte);
 241                                         continue;
 242                                 }
 243                                 set_pte(pt_dir, pte);
 244                                 pfn++;
 245                         }
 246                 }
 247         }
 248
 249         S390_lowcore.kernel_asce = pgdir_k;
 250
 251         /* enable virtual mapping in kernel mode */
 252         __asm__ __volatile__("lctlg 1,1,%0\n\t"
 253                              "lctlg 7,7,%0\n\t"
 254                              "lctlg 13,13,%0\n\t"
 255                              "ssm   %1"
 256                              : :"m" (pgdir_k), "m" (ssm_mask));
 257
 258         local_flush_tlb();
 259
 260         return;
 261 }
 262 #endif /* CONFIG_64BIT */
 263
 264 void __init mem_init(void)
 265 {
 266         unsigned long codesize, reservedpages, datasize, initsize;
 267
 268         max_mapnr = num_physpages = max_low_pfn;
 269         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 270
 271         /* clear the zero-page */
 272         memset(empty_zero_page, 0, PAGE_SIZE);
 273
 274         /* this will put all low memory onto the freelists */
 275         totalram_pages += free_all_bootmem();
 276
 277         reservedpages = 0;
 278
 279         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 280         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 281         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 282         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 283                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 284                 max_mapnr << (PAGE_SHIFT-10),
 285                 codesize >> 10,
 286                 reservedpages << (PAGE_SHIFT-10),
 287                 datasize >>10,
 288                 initsize >> 10);
 289         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 290                (unsigned long)&__start_rodata,
 291                PFN_ALIGN((unsigned long)&__end_rodata) - 1);
 292 }
 293
 294 void free_initmem(void)
 295 {
 296         unsigned long addr;
 297
 298         addr = (unsigned long)(&__init_begin);
 299         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 300                 ClearPageReserved(virt_to_page(addr));
 301                 init_page_count(virt_to_page(addr));
 302                 free_page(addr);
 303                 totalram_pages++;
 304         }
 305         printk ("Freeing unused kernel memory: %ldk freed\n",
 306                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 307 }
 308
 309 #ifdef CONFIG_BLK_DEV_INITRD
 310 void free_initrd_mem(unsigned long start, unsigned long end)
 311 {
 312         if (start < end)
 313                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 314         for (; start < end; start += PAGE_SIZE) {
 315                 ClearPageReserved(virt_to_page(start));
 316                 init_page_count(virt_to_page(start));
 317                 free_page(start);
 318                 totalram_pages++;
 319         }
 320 }
 321 #endif