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         unsigned long zones_size[MAX_NR_ZONES];
 112
 113         ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
 114         ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
 115
 116         memset(zones_size, 0, sizeof(zones_size));
 117         zones_size[ZONE_DMA] = max_low_pfn;
 118         free_area_init_node(0, &contig_page_data, zones_size,
 119                             __pa(PAGE_OFFSET) >> PAGE_SHIFT,
 120                             zholes_size);
 121
 122         /* unmap whole virtual address space */
 123
 124         pg_dir = swapper_pg_dir;
 125
 126         for (i = 0; i < PTRS_PER_PGD; i++)
 127                 pmd_clear((pmd_t *) pg_dir++);
 128
 129         /*
 130          * map whole physical memory to virtual memory (identity mapping)
 131          */
 132
 133         pg_dir = swapper_pg_dir;
 134
 135         while (pfn < max_low_pfn) {
 136                 /*
 137                  * pg_table is physical at this point
 138                  */
 139                 pg_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
 140
 141                 pmd_populate_kernel(&init_mm, (pmd_t *) pg_dir, pg_table);
 142                 pg_dir++;
 143
 144                 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
 145                         if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
 146                                 pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
 147                         else
 148                                 pte = pfn_pte(pfn, PAGE_KERNEL);
 149                         if (pfn >= max_low_pfn)
 150                                 pte_val(pte) = _PAGE_TYPE_EMPTY;
 151                         set_pte(pg_table, pte);
 152                         pfn++;
 153                 }
 154         }
 155
 156         S390_lowcore.kernel_asce = pgdir_k;
 157
 158         /* enable virtual mapping in kernel mode */
 159         __asm__ __volatile__("    LCTL  1,1,%0\n"
 160                              "    LCTL  7,7,%0\n"
 161                              "    LCTL  13,13,%0\n"
 162                              "    SSM   %1"
 163                              : : "m" (pgdir_k), "m" (ssm_mask));
 164
 165         local_flush_tlb();
 166         return;
 167 }
 168
 169 #else /* CONFIG_64BIT */
 170
 171 void __init paging_init(void)
 172 {
 173         pgd_t * pg_dir;
 174         pmd_t * pm_dir;
 175         pte_t * pt_dir;
 176         pte_t   pte;
 177         int     i,j,k;
 178         unsigned long pfn = 0;
 179         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
 180           _KERN_REGION_TABLE;
 181         static const int ssm_mask = 0x04000000L;
 182         unsigned long zones_size[MAX_NR_ZONES];
 183         unsigned long dma_pfn, high_pfn;
 184         unsigned long ro_start_pfn, ro_end_pfn;
 185
 186         memset(zones_size, 0, sizeof(zones_size));
 187         dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
 188         high_pfn = max_low_pfn;
 189         ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
 190         ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
 191
 192         if (dma_pfn > high_pfn)
 193                 zones_size[ZONE_DMA] = high_pfn;
 194         else {
 195                 zones_size[ZONE_DMA] = dma_pfn;
 196                 zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
 197         }
 198
 199         /* Initialize mem_map[].  */
 200         free_area_init_node(0, &contig_page_data, zones_size,
 201                             __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
 202
 203         /*
 204          * map whole physical memory to virtual memory (identity mapping)
 205          */
 206
 207         pg_dir = swapper_pg_dir;
 208
 209         for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
 210
 211                 if (pfn >= max_low_pfn) {
 212                         pgd_clear(pg_dir);
 213                         continue;
 214                 }
 215
 216                 pm_dir = (pmd_t *) alloc_bootmem_pages(PAGE_SIZE * 4);
 217                 pgd_populate(&init_mm, pg_dir, pm_dir);
 218
 219                 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
 220                         if (pfn >= max_low_pfn) {
 221                                 pmd_clear(pm_dir);
 222                                 continue;
 223                         }
 224
 225                         pt_dir = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
 226                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
 227
 228                         for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
 229                                 if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
 230                                         pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
 231                                 else
 232                                         pte = pfn_pte(pfn, PAGE_KERNEL);
 233                                 if (pfn >= max_low_pfn)
 234                                         pte_val(pte) = _PAGE_TYPE_EMPTY;
 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_64BIT */
 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         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 282                (unsigned long)&__start_rodata,
 283                PFN_ALIGN((unsigned long)&__end_rodata) - 1);
 284 }
 285
 286 void free_initmem(void)
 287 {
 288         unsigned long addr;
 289
 290         addr = (unsigned long)(&__init_begin);
 291         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 292                 ClearPageReserved(virt_to_page(addr));
 293                 init_page_count(virt_to_page(addr));
 294                 free_page(addr);
 295                 totalram_pages++;
 296         }
 297         printk ("Freeing unused kernel memory: %ldk freed\n",
 298                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 299 }
 300
 301 #ifdef CONFIG_BLK_DEV_INITRD
 302 void free_initrd_mem(unsigned long start, unsigned long end)
 303 {
 304         if (start < end)
 305                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 306         for (; start < end; start += PAGE_SIZE) {
 307                 ClearPageReserved(virt_to_page(start));
 308                 init_page_count(virt_to_page(start));
 309                 free_page(start);
 310                 totalram_pages++;
 311         }
 312 }
 313 #endif