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