LXR linux/arch/s390/mm/init.c

   1/*
   2 *  S390 version
   3 *    Copyright IBM Corp. 1999
   4 *    Author(s): Hartmut Penner (hp@de.ibm.com)
   5 *
   6 *  Derived from "arch/i386/mm/init.c"
   7 *    Copyright (C) 1995  Linus Torvalds
   8 */
   9
  10#include <linux/signal.h>
  11#include <linux/sched.h>
  12#include <linux/kernel.h>
  13#include <linux/errno.h>
  14#include <linux/string.h>
  15#include <linux/types.h>
  16#include <linux/ptrace.h>
  17#include <linux/mman.h>
  18#include <linux/mm.h>
  19#include <linux/swap.h>
  20#include <linux/smp.h>
  21#include <linux/init.h>
  22#include <linux/pagemap.h>
  23#include <linux/bootmem.h>
  24#include <linux/pfn.h>
  25#include <linux/poison.h>
  26#include <linux/initrd.h>
  27#include <linux/export.h>
  28#include <linux/gfp.h>
  29#include <asm/processor.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#include <asm/ctl_reg.h>
  39
  40pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  41
  42unsigned long empty_zero_page, zero_page_mask;
  43EXPORT_SYMBOL(empty_zero_page);
  44
  45static unsigned long __init setup_zero_pages(void)
  46{
  47        struct cpuid cpu_id;
  48        unsigned int order;
  49        unsigned long size;
  50        struct page *page;
  51        int i;
  52
  53        get_cpu_id(&cpu_id);
  54        switch (cpu_id.machine) {
  55        case 0x9672:    /* g5 */
  56        case 0x2064:    /* z900 */
  57        case 0x2066:    /* z900 */
  58        case 0x2084:    /* z990 */
  59        case 0x2086:    /* z990 */
  60        case 0x2094:    /* z9-109 */
  61        case 0x2096:    /* z9-109 */
  62                order = 0;
  63                break;
  64        case 0x2097:    /* z10 */
  65        case 0x2098:    /* z10 */
  66        default:
  67                order = 2;
  68                break;
  69        }
  70
  71        empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  72        if (!empty_zero_page)
  73                panic("Out of memory in setup_zero_pages");
  74
  75        page = virt_to_page((void *) empty_zero_page);
  76        split_page(page, order);
  77        for (i = 1 << order; i > 0; i--) {
  78                SetPageReserved(page);
  79                page++;
  80        }
  81
  82        size = PAGE_SIZE << order;
  83        zero_page_mask = (size - 1) & PAGE_MASK;
  84
  85        return 1UL << order;
  86}
  87
  88/*
  89 * paging_init() sets up the page tables
  90 */
  91void __init paging_init(void)
  92{
  93        unsigned long max_zone_pfns[MAX_NR_ZONES];
  94        unsigned long pgd_type, asce_bits;
  95
  96        init_mm.pgd = swapper_pg_dir;
  97#ifdef CONFIG_64BIT
  98        if (VMALLOC_END > (1UL << 42)) {
  99                asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
 100                pgd_type = _REGION2_ENTRY_EMPTY;
 101        } else {
 102                asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
 103                pgd_type = _REGION3_ENTRY_EMPTY;
 104        }
 105#else
 106        asce_bits = _ASCE_TABLE_LENGTH;
 107        pgd_type = _SEGMENT_ENTRY_EMPTY;
 108#endif
 109        S390_lowcore.kernel_asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
 110        clear_table((unsigned long *) init_mm.pgd, pgd_type,
 111                    sizeof(unsigned long)*2048);
 112        vmem_map_init();
 113
 114        /* enable virtual mapping in kernel mode */
 115        __ctl_load(S390_lowcore.kernel_asce, 1, 1);
 116        __ctl_load(S390_lowcore.kernel_asce, 7, 7);
 117        __ctl_load(S390_lowcore.kernel_asce, 13, 13);
 118        arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));
 119
 120        atomic_set(&init_mm.context.attach_count, 1);
 121
 122        sparse_memory_present_with_active_regions(MAX_NUMNODES);
 123        sparse_init();
 124        memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 125        max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 126        max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 127        free_area_init_nodes(max_zone_pfns);
 128        fault_init();
 129}
 130
 131void __init mem_init(void)
 132{
 133        unsigned long codesize, reservedpages, datasize, initsize;
 134
 135        max_mapnr = num_physpages = max_low_pfn;
 136        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 137
 138        /* Setup guest page hinting */
 139        cmma_init();
 140
 141        /* this will put all low memory onto the freelists */
 142        totalram_pages += free_all_bootmem();
 143        totalram_pages -= setup_zero_pages();   /* Setup zeroed pages. */
 144
 145        reservedpages = 0;
 146
 147        codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 148        datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 149        initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 150        printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 151                nr_free_pages() << (PAGE_SHIFT-10),
 152                max_mapnr << (PAGE_SHIFT-10),
 153                codesize >> 10,
 154                reservedpages << (PAGE_SHIFT-10),
 155                datasize >>10,
 156                initsize >> 10);
 157        printk("Write protected kernel read-only data: %#lx - %#lx\n",
 158               (unsigned long)&_stext,
 159               PFN_ALIGN((unsigned long)&_eshared) - 1);
 160}
 161
 162#ifdef CONFIG_DEBUG_PAGEALLOC
 163void kernel_map_pages(struct page *page, int numpages, int enable)
 164{
 165        pgd_t *pgd;
 166        pud_t *pud;
 167        pmd_t *pmd;
 168        pte_t *pte;
 169        unsigned long address;
 170        int i;
 171
 172        for (i = 0; i < numpages; i++) {
 173                address = page_to_phys(page + i);
 174                pgd = pgd_offset_k(address);
 175                pud = pud_offset(pgd, address);
 176                pmd = pmd_offset(pud, address);
 177                pte = pte_offset_kernel(pmd, address);
 178                if (!enable) {
 179                        __ptep_ipte(address, pte);
 180                        pte_val(*pte) = _PAGE_TYPE_EMPTY;
 181                        continue;
 182                }
 183                *pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
 184                /* Flush cpu write queue. */
 185                mb();
 186        }
 187}
 188#endif
 189
 190void free_init_pages(char *what, unsigned long begin, unsigned long end)
 191{
 192        unsigned long addr = begin;
 193
 194        if (begin >= end)
 195                return;
 196        for (; addr < end; addr += PAGE_SIZE) {
 197                ClearPageReserved(virt_to_page(addr));
 198                init_page_count(virt_to_page(addr));
 199                memset((void *)(addr & PAGE_MASK), POISON_FREE_INITMEM,
 200                       PAGE_SIZE);
 201                free_page(addr);
 202                totalram_pages++;
 203        }
 204        printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
 205}
 206
 207void free_initmem(void)
 208{
 209        free_init_pages("unused kernel memory",
 210                        (unsigned long)&__init_begin,
 211                        (unsigned long)&__init_end);
 212}
 213
 214#ifdef CONFIG_BLK_DEV_INITRD
 215void __init free_initrd_mem(unsigned long start, unsigned long end)
 216{
 217        free_init_pages("initrd memory", start, end);
 218}
 219#endif
 220
 221#ifdef CONFIG_MEMORY_HOTPLUG
 222int arch_add_memory(int nid, u64 start, u64 size)
 223{
 224        unsigned long zone_start_pfn, zone_end_pfn, nr_pages;
 225        unsigned long start_pfn = PFN_DOWN(start);
 226        unsigned long size_pages = PFN_DOWN(size);
 227        struct zone *zone;
 228        int rc;
 229
 230        rc = vmem_add_mapping(start, size);
 231        if (rc)
 232                return rc;
 233        for_each_zone(zone) {
 234                if (zone_idx(zone) != ZONE_MOVABLE) {
 235                        /* Add range within existing zone limits */
 236                        zone_start_pfn = zone->zone_start_pfn;
 237                        zone_end_pfn = zone->zone_start_pfn +
 238                                       zone->spanned_pages;
 239                } else {
 240                        /* Add remaining range to ZONE_MOVABLE */
 241                        zone_start_pfn = start_pfn;
 242                        zone_end_pfn = start_pfn + size_pages;
 243                }
 244                if (start_pfn < zone_start_pfn || start_pfn >= zone_end_pfn)
 245                        continue;
 246                nr_pages = (start_pfn + size_pages > zone_end_pfn) ?
 247                           zone_end_pfn - start_pfn : size_pages;
 248                rc = __add_pages(nid, zone, start_pfn, nr_pages);
 249                if (rc)
 250                        break;
 251                start_pfn += nr_pages;
 252                size_pages -= nr_pages;
 253                if (!size_pages)
 254                        break;
 255        }
 256        if (rc)
 257                vmem_remove_mapping(start, size);
 258        return rc;
 259}
 260#endif /* CONFIG_MEMORY_HOTPLUG */
 261