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   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         asm volatile(
  49 #ifdef CONFIG_64BIT
  50                 "       sam31\n"
  51                 "       diag    %0,%0,0x10\n"
  52                 "0:     sam64\n"
  53 #else
  54                 "       diag    %0,%0,0x10\n"
  55                 "0:\n"
  56 #endif
  57                 EX_TABLE(0b,0b)
  58                 : : "a" (addr));
  59 }
  60
  61 void show_mem(void)
  62 {
  63         int i, total = 0, reserved = 0;
  64         int shared = 0, cached = 0;
  65         struct page *page;
  66
  67         printk("Mem-info:\n");
  68         show_free_areas();
  69         printk("Free swap:       %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
  70         i = max_mapnr;
  71         while (i-- > 0) {
  72                 page = pfn_to_page(i);
  73                 total++;
  74                 if (PageReserved(page))
  75                         reserved++;
  76                 else if (PageSwapCache(page))
  77                         cached++;
  78                 else if (page_count(page))
  79                         shared += page_count(page) - 1;
  80         }
  81         printk("%d pages of RAM\n",total);
  82         printk("%d reserved pages\n",reserved);
  83         printk("%d pages shared\n",shared);
  84         printk("%d pages swap cached\n",cached);
  85 }
  86
  87 /*
  88  * paging_init() sets up the page tables
  89  */
  90
  91 #ifndef CONFIG_64BIT
  92 void __init paging_init(void)
  93 {
  94         pgd_t * pg_dir;
  95         pte_t * pg_table;
  96         pte_t   pte;
  97         int     i;
  98         unsigned long tmp;
  99         unsigned long pfn = 0;
 100         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
 101         static const int ssm_mask = 0x04000000L;
 102         unsigned long ro_start_pfn, ro_end_pfn;
 103         unsigned long max_zone_pfns[MAX_NR_ZONES];
 104
 105         ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
 106         ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
 107
 108         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 109         max_zone_pfns[ZONE_DMA] = max_low_pfn;
 110         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 111         free_area_init_nodes(max_zone_pfns);
 112
 113         /* unmap whole virtual address space */
 114
 115         pg_dir = swapper_pg_dir;
 116
 117         for (i = 0; i < PTRS_PER_PGD; i++)
 118                 pmd_clear((pmd_t *) pg_dir++);
 119
 120         /*
 121          * map whole physical memory to virtual memory (identity mapping)
 122          */
 123
 124         pg_dir = swapper_pg_dir;
 125
 126         while (pfn < max_low_pfn) {
 127                 /*
 128                  * pg_table is physical at this point
 129                  */
 130                 pg_table = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
 131
 132                 pmd_populate_kernel(&init_mm, (pmd_t *) pg_dir, pg_table);
 133                 pg_dir++;
 134
 135                 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
 136                         if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
 137                                 pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
 138                         else
 139                                 pte = pfn_pte(pfn, PAGE_KERNEL);
 140                         if (pfn >= max_low_pfn)
 141                                 pte_val(pte) = _PAGE_TYPE_EMPTY;
 142                         set_pte(pg_table, pte);
 143                         pfn++;
 144                 }
 145         }
 146
 147         S390_lowcore.kernel_asce = pgdir_k;
 148
 149         /* enable virtual mapping in kernel mode */
 150         __ctl_load(pgdir_k, 1, 1);
 151         __ctl_load(pgdir_k, 7, 7);
 152         __ctl_load(pgdir_k, 13, 13);
 153         __raw_local_irq_ssm(ssm_mask);
 154
 155         local_flush_tlb();
 156 }
 157
 158 #else /* CONFIG_64BIT */
 159
 160 void __init paging_init(void)
 161 {
 162         pgd_t * pg_dir;
 163         pmd_t * pm_dir;
 164         pte_t * pt_dir;
 165         pte_t   pte;
 166         int     i,j,k;
 167         unsigned long pfn = 0;
 168         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
 169           _KERN_REGION_TABLE;
 170         static const int ssm_mask = 0x04000000L;
 171         unsigned long ro_start_pfn, ro_end_pfn;
 172         unsigned long max_zone_pfns[MAX_NR_ZONES];
 173
 174         ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
 175         ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
 176
 177         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 178         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 179         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 180         free_area_init_nodes(max_zone_pfns);
 181
 182         /*
 183          * map whole physical memory to virtual memory (identity mapping)
 184          */
 185
 186         pg_dir = swapper_pg_dir;
 187
 188         for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
 189
 190                 if (pfn >= max_low_pfn) {
 191                         pgd_clear(pg_dir);
 192                         continue;
 193                 }
 194
 195                 pm_dir = (pmd_t *) alloc_bootmem_pages(PAGE_SIZE * 4);
 196                 pgd_populate(&init_mm, pg_dir, pm_dir);
 197
 198                 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
 199                         if (pfn >= max_low_pfn) {
 200                                 pmd_clear(pm_dir);
 201                                 continue;
 202                         }
 203
 204                         pt_dir = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
 205                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
 206
 207                         for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
 208                                 if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
 209                                         pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
 210                                 else
 211                                         pte = pfn_pte(pfn, PAGE_KERNEL);
 212                                 if (pfn >= max_low_pfn)
 213                                         pte_val(pte) = _PAGE_TYPE_EMPTY;
 214                                 set_pte(pt_dir, pte);
 215                                 pfn++;
 216                         }
 217                 }
 218         }
 219
 220         S390_lowcore.kernel_asce = pgdir_k;
 221
 222         /* enable virtual mapping in kernel mode */
 223         __ctl_load(pgdir_k, 1, 1);
 224         __ctl_load(pgdir_k, 7, 7);
 225         __ctl_load(pgdir_k, 13, 13);
 226         __raw_local_irq_ssm(ssm_mask);
 227
 228         local_flush_tlb();
 229 }
 230 #endif /* CONFIG_64BIT */
 231
 232 void __init mem_init(void)
 233 {
 234         unsigned long codesize, reservedpages, datasize, initsize;
 235
 236         max_mapnr = num_physpages = max_low_pfn;
 237         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 238
 239         /* clear the zero-page */
 240         memset(empty_zero_page, 0, PAGE_SIZE);
 241
 242         /* this will put all low memory onto the freelists */
 243         totalram_pages += free_all_bootmem();
 244
 245         reservedpages = 0;
 246
 247         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 248         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 249         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 250         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 251                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 252                 max_mapnr << (PAGE_SHIFT-10),
 253                 codesize >> 10,
 254                 reservedpages << (PAGE_SHIFT-10),
 255                 datasize >>10,
 256                 initsize >> 10);
 257         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 258                (unsigned long)&__start_rodata,
 259                PFN_ALIGN((unsigned long)&__end_rodata) - 1);
 260 }
 261
 262 void free_initmem(void)
 263 {
 264         unsigned long addr;
 265
 266         addr = (unsigned long)(&__init_begin);
 267         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 268                 ClearPageReserved(virt_to_page(addr));
 269                 init_page_count(virt_to_page(addr));
 270                 free_page(addr);
 271                 totalram_pages++;
 272         }
 273         printk ("Freeing unused kernel memory: %ldk freed\n",
 274                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 275 }
 276
 277 #ifdef CONFIG_BLK_DEV_INITRD
 278 void free_initrd_mem(unsigned long start, unsigned long end)
 279 {
 280         if (start < end)
 281                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 282         for (; start < end; start += PAGE_SIZE) {
 283                 ClearPageReserved(virt_to_page(start));
 284                 init_page_count(virt_to_page(start));
 285                 free_page(start);
 286                 totalram_pages++;
 287         }
 288 }
 289 #endif