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         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 extern unsigned long __initdata zholes_size[];
  88 /*
  89  * paging_init() sets up the page tables
  90  */
  91
  92 #ifndef CONFIG_64BIT
  93 void __init paging_init(void)
  94 {
  95         pgd_t * pg_dir;
  96         pte_t * pg_table;
  97         pte_t   pte;
  98         int     i;
  99         unsigned long tmp;
 100         unsigned long pfn = 0;
 101         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
 102         static const int ssm_mask = 0x04000000L;
 103         unsigned long ro_start_pfn, ro_end_pfn;
 104         unsigned long zones_size[MAX_NR_ZONES];
 105
 106         ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
 107         ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
 108
 109         memset(zones_size, 0, sizeof(zones_size));
 110         zones_size[ZONE_DMA] = max_low_pfn;
 111         free_area_init_node(0, &contig_page_data, zones_size,
 112                             __pa(PAGE_OFFSET) >> PAGE_SHIFT,
 113                             zholes_size);
 114
 115         /* unmap whole virtual address space */
 116
 117         pg_dir = swapper_pg_dir;
 118
 119         for (i = 0; i < PTRS_PER_PGD; 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                 pmd_populate_kernel(&init_mm, (pmd_t *) pg_dir, pg_table);
 135                 pg_dir++;
 136
 137                 for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
 138                         if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
 139                                 pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
 140                         else
 141                                 pte = pfn_pte(pfn, PAGE_KERNEL);
 142                         if (pfn >= max_low_pfn)
 143                                 pte_val(pte) = _PAGE_TYPE_EMPTY;
 144                         set_pte(pg_table, pte);
 145                         pfn++;
 146                 }
 147         }
 148
 149         S390_lowcore.kernel_asce = pgdir_k;
 150
 151         /* enable virtual mapping in kernel mode */
 152         __ctl_load(pgdir_k, 1, 1);
 153         __ctl_load(pgdir_k, 7, 7);
 154         __ctl_load(pgdir_k, 13, 13);
 155         __raw_local_irq_ssm(ssm_mask);
 156
 157         local_flush_tlb();
 158 }
 159
 160 #else /* CONFIG_64BIT */
 161
 162 void __init paging_init(void)
 163 {
 164         pgd_t * pg_dir;
 165         pmd_t * pm_dir;
 166         pte_t * pt_dir;
 167         pte_t   pte;
 168         int     i,j,k;
 169         unsigned long pfn = 0;
 170         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
 171           _KERN_REGION_TABLE;
 172         static const int ssm_mask = 0x04000000L;
 173         unsigned long zones_size[MAX_NR_ZONES];
 174         unsigned long dma_pfn, high_pfn;
 175         unsigned long ro_start_pfn, ro_end_pfn;
 176
 177         memset(zones_size, 0, sizeof(zones_size));
 178         dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
 179         high_pfn = max_low_pfn;
 180         ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
 181         ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
 182
 183         if (dma_pfn > high_pfn)
 184                 zones_size[ZONE_DMA] = high_pfn;
 185         else {
 186                 zones_size[ZONE_DMA] = dma_pfn;
 187                 zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
 188         }
 189
 190         /* Initialize mem_map[].  */
 191         free_area_init_node(0, &contig_page_data, zones_size,
 192                             __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
 193
 194         /*
 195          * map whole physical memory to virtual memory (identity mapping)
 196          */
 197
 198         pg_dir = swapper_pg_dir;
 199
 200         for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
 201
 202                 if (pfn >= max_low_pfn) {
 203                         pgd_clear(pg_dir);
 204                         continue;
 205                 }
 206
 207                 pm_dir = (pmd_t *) alloc_bootmem_pages(PAGE_SIZE * 4);
 208                 pgd_populate(&init_mm, pg_dir, pm_dir);
 209
 210                 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
 211                         if (pfn >= max_low_pfn) {
 212                                 pmd_clear(pm_dir);
 213                                 continue;
 214                         }
 215
 216                         pt_dir = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
 217                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
 218
 219                         for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
 220                                 if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
 221                                         pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
 222                                 else
 223                                         pte = pfn_pte(pfn, PAGE_KERNEL);
 224                                 if (pfn >= max_low_pfn)
 225                                         pte_val(pte) = _PAGE_TYPE_EMPTY;
 226                                 set_pte(pt_dir, pte);
 227                                 pfn++;
 228                         }
 229                 }
 230         }
 231
 232         S390_lowcore.kernel_asce = pgdir_k;
 233
 234         /* enable virtual mapping in kernel mode */
 235         __ctl_load(pgdir_k, 1, 1);
 236         __ctl_load(pgdir_k, 7, 7);
 237         __ctl_load(pgdir_k, 13, 13);
 238         __raw_local_irq_ssm(ssm_mask);
 239
 240         local_flush_tlb();
 241 }
 242 #endif /* CONFIG_64BIT */
 243
 244 void __init mem_init(void)
 245 {
 246         unsigned long codesize, reservedpages, datasize, initsize;
 247
 248         max_mapnr = num_physpages = max_low_pfn;
 249         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 250
 251         /* clear the zero-page */
 252         memset(empty_zero_page, 0, PAGE_SIZE);
 253
 254         /* this will put all low memory onto the freelists */
 255         totalram_pages += free_all_bootmem();
 256
 257         reservedpages = 0;
 258
 259         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 260         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 261         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 262         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 263                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 264                 max_mapnr << (PAGE_SHIFT-10),
 265                 codesize >> 10,
 266                 reservedpages << (PAGE_SHIFT-10),
 267                 datasize >>10,
 268                 initsize >> 10);
 269         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 270                (unsigned long)&__start_rodata,
 271                PFN_ALIGN((unsigned long)&__end_rodata) - 1);
 272 }
 273
 274 void free_initmem(void)
 275 {
 276         unsigned long addr;
 277
 278         addr = (unsigned long)(&__init_begin);
 279         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 280                 ClearPageReserved(virt_to_page(addr));
 281                 init_page_count(virt_to_page(addr));
 282                 free_page(addr);
 283                 totalram_pages++;
 284         }
 285         printk ("Freeing unused kernel memory: %ldk freed\n",
 286                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 287 }
 288
 289 #ifdef CONFIG_BLK_DEV_INITRD
 290 void free_initrd_mem(unsigned long start, unsigned long end)
 291 {
 292         if (start < end)
 293                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 294         for (; start < end; start += PAGE_SIZE) {
 295                 ClearPageReserved(virt_to_page(start));
 296                 init_page_count(virt_to_page(start));
 297                 free_page(start);
 298                 totalram_pages++;
 299         }
 300 }
 301 #endif