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 extern unsigned long __initdata zholes_size[];
  86 /*
  87  * paging_init() sets up the page tables
  88  */
  89
  90 #ifndef CONFIG_64BIT
  91 void __init paging_init(void)
  92 {
  93         pgd_t * pg_dir;
  94         pte_t * pg_table;
  95         pte_t   pte;
  96         int     i;
  97         unsigned long tmp;
  98         unsigned long pfn = 0;
  99         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
 100         static const int ssm_mask = 0x04000000L;
 101         unsigned long ro_start_pfn, ro_end_pfn;
 102         unsigned long zones_size[MAX_NR_ZONES];
 103
 104         ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
 105         ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
 106
 107         memset(zones_size, 0, sizeof(zones_size));
 108         zones_size[ZONE_DMA] = max_low_pfn;
 109         free_area_init_node(0, &contig_page_data, zones_size,
 110                             __pa(PAGE_OFFSET) >> PAGE_SHIFT,
 111                             zholes_size);
 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         return;
 157 }
 158
 159 #else /* CONFIG_64BIT */
 160
 161 void __init paging_init(void)
 162 {
 163         pgd_t * pg_dir;
 164         pmd_t * pm_dir;
 165         pte_t * pt_dir;
 166         pte_t   pte;
 167         int     i,j,k;
 168         unsigned long pfn = 0;
 169         unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
 170           _KERN_REGION_TABLE;
 171         static const int ssm_mask = 0x04000000L;
 172         unsigned long zones_size[MAX_NR_ZONES];
 173         unsigned long dma_pfn, high_pfn;
 174         unsigned long ro_start_pfn, ro_end_pfn;
 175
 176         memset(zones_size, 0, sizeof(zones_size));
 177         dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
 178         high_pfn = max_low_pfn;
 179         ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
 180         ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
 181
 182         if (dma_pfn > high_pfn)
 183                 zones_size[ZONE_DMA] = high_pfn;
 184         else {
 185                 zones_size[ZONE_DMA] = dma_pfn;
 186                 zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
 187         }
 188
 189         /* Initialize mem_map[].  */
 190         free_area_init_node(0, &contig_page_data, zones_size,
 191                             __pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
 192
 193         /*
 194          * map whole physical memory to virtual memory (identity mapping)
 195          */
 196
 197         pg_dir = swapper_pg_dir;
 198
 199         for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
 200
 201                 if (pfn >= max_low_pfn) {
 202                         pgd_clear(pg_dir);
 203                         continue;
 204                 }
 205
 206                 pm_dir = (pmd_t *) alloc_bootmem_pages(PAGE_SIZE * 4);
 207                 pgd_populate(&init_mm, pg_dir, pm_dir);
 208
 209                 for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
 210                         if (pfn >= max_low_pfn) {
 211                                 pmd_clear(pm_dir);
 212                                 continue;
 213                         }
 214
 215                         pt_dir = (pte_t *) alloc_bootmem_pages(PAGE_SIZE);
 216                         pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
 217
 218                         for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
 219                                 if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
 220                                         pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
 221                                 else
 222                                         pte = pfn_pte(pfn, PAGE_KERNEL);
 223                                 if (pfn >= max_low_pfn)
 224                                         pte_val(pte) = _PAGE_TYPE_EMPTY;
 225                                 set_pte(pt_dir, pte);
 226                                 pfn++;
 227                         }
 228                 }
 229         }
 230
 231         S390_lowcore.kernel_asce = pgdir_k;
 232
 233         /* enable virtual mapping in kernel mode */
 234         __ctl_load(pgdir_k, 1, 1);
 235         __ctl_load(pgdir_k, 7, 7);
 236         __ctl_load(pgdir_k, 13, 13);
 237         __raw_local_irq_ssm(ssm_mask);
 238
 239         local_flush_tlb();
 240
 241         return;
 242 }
 243 #endif /* CONFIG_64BIT */
 244
 245 void __init mem_init(void)
 246 {
 247         unsigned long codesize, reservedpages, datasize, initsize;
 248
 249         max_mapnr = num_physpages = max_low_pfn;
 250         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 251
 252         /* clear the zero-page */
 253         memset(empty_zero_page, 0, PAGE_SIZE);
 254
 255         /* this will put all low memory onto the freelists */
 256         totalram_pages += free_all_bootmem();
 257
 258         reservedpages = 0;
 259
 260         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 261         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 262         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 263         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 264                 (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 265                 max_mapnr << (PAGE_SHIFT-10),
 266                 codesize >> 10,
 267                 reservedpages << (PAGE_SHIFT-10),
 268                 datasize >>10,
 269                 initsize >> 10);
 270         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 271                (unsigned long)&__start_rodata,
 272                PFN_ALIGN((unsigned long)&__end_rodata) - 1);
 273 }
 274
 275 void free_initmem(void)
 276 {
 277         unsigned long addr;
 278
 279         addr = (unsigned long)(&__init_begin);
 280         for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 281                 ClearPageReserved(virt_to_page(addr));
 282                 init_page_count(virt_to_page(addr));
 283                 free_page(addr);
 284                 totalram_pages++;
 285         }
 286         printk ("Freeing unused kernel memory: %ldk freed\n",
 287                 ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 288 }
 289
 290 #ifdef CONFIG_BLK_DEV_INITRD
 291 void free_initrd_mem(unsigned long start, unsigned long end)
 292 {
 293         if (start < end)
 294                 printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 295         for (; start < end; start += PAGE_SIZE) {
 296                 ClearPageReserved(virt_to_page(start));
 297                 init_page_count(virt_to_page(start));
 298                 free_page(start);
 299                 totalram_pages++;
 300         }
 301 }
 302 #endif