LXR linux/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#include <linux/poison.h>
  28#include <linux/initrd.h>
  29#include <linux/gfp.h>
  30#include <asm/processor.h>
  31#include <asm/system.h>
  32#include <asm/uaccess.h>
  33#include <asm/pgtable.h>
  34#include <asm/pgalloc.h>
  35#include <asm/dma.h>
  36#include <asm/lowcore.h>
  37#include <asm/tlb.h>
  38#include <asm/tlbflush.h>
  39#include <asm/sections.h>
  40
  41pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  42
  43unsigned long empty_zero_page, zero_page_mask;
  44EXPORT_SYMBOL(empty_zero_page);
  45
  46static unsigned long setup_zero_pages(void)
  47{
  48        struct cpuid cpu_id;
  49        unsigned int order;
  50        unsigned long size;
  51        struct page *page;
  52        int i;
  53
  54        get_cpu_id(&cpu_id);
  55        switch (cpu_id.machine) {
  56        case 0x9672:    /* g5 */
  57        case 0x2064:    /* z900 */
  58        case 0x2066:    /* z900 */
  59        case 0x2084:    /* z990 */
  60        case 0x2086:    /* z990 */
  61        case 0x2094:    /* z9-109 */
  62        case 0x2096:    /* z9-109 */
  63                order = 0;
  64                break;
  65        case 0x2097:    /* z10 */
  66        case 0x2098:    /* z10 */
  67        default:
  68                order = 2;
  69                break;
  70        }
  71
  72        empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  73        if (!empty_zero_page)
  74                panic("Out of memory in setup_zero_pages");
  75
  76        page = virt_to_page((void *) empty_zero_page);
  77        split_page(page, order);
  78        for (i = 1 << order; i > 0; i--) {
  79                SetPageReserved(page);
  80                page++;
  81        }
  82
  83        size = PAGE_SIZE << order;
  84        zero_page_mask = (size - 1) & PAGE_MASK;
  85
  86        return 1UL << order;
  87}
  88
  89/*
  90 * paging_init() sets up the page tables
  91 */
  92void __init paging_init(void)
  93{
  94        unsigned long max_zone_pfns[MAX_NR_ZONES];
  95        unsigned long pgd_type;
  96
  97        init_mm.pgd = swapper_pg_dir;
  98        S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
  99#ifdef CONFIG_64BIT
 100        /* A three level page table (4TB) is enough for the kernel space. */
 101        S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
 102        pgd_type = _REGION3_ENTRY_EMPTY;
 103#else
 104        S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
 105        pgd_type = _SEGMENT_ENTRY_EMPTY;
 106#endif
 107        clear_table((unsigned long *) init_mm.pgd, pgd_type,
 108                    sizeof(unsigned long)*2048);
 109        vmem_map_init();
 110
 111        /* enable virtual mapping in kernel mode */
 112        __ctl_load(S390_lowcore.kernel_asce, 1, 1);
 113        __ctl_load(S390_lowcore.kernel_asce, 7, 7);
 114        __ctl_load(S390_lowcore.kernel_asce, 13, 13);
 115        arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));
 116
 117        atomic_set(&init_mm.context.attach_count, 1);
 118
 119        sparse_memory_present_with_active_regions(MAX_NUMNODES);
 120        sparse_init();
 121        memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 122#ifdef CONFIG_ZONE_DMA
 123        max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 124#endif
 125        max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 126        free_area_init_nodes(max_zone_pfns);
 127        fault_init();
 128}
 129
 130void __init mem_init(void)
 131{
 132        unsigned long codesize, reservedpages, datasize, initsize;
 133
 134        max_mapnr = num_physpages = max_low_pfn;
 135        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 136
 137        /* Setup guest page hinting */
 138        cmma_init();
 139
 140        /* this will put all low memory onto the freelists */
 141        totalram_pages += free_all_bootmem();
 142        totalram_pages -= setup_zero_pages();   /* Setup zeroed pages. */
 143
 144        reservedpages = 0;
 145
 146        codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 147        datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 148        initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 149        printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 150                nr_free_pages() << (PAGE_SHIFT-10),
 151                max_mapnr << (PAGE_SHIFT-10),
 152                codesize >> 10,
 153                reservedpages << (PAGE_SHIFT-10),
 154                datasize >>10,
 155                initsize >> 10);
 156        printk("Write protected kernel read-only data: %#lx - %#lx\n",
 157               (unsigned long)&_stext,
 158               PFN_ALIGN((unsigned long)&_eshared) - 1);
 159}
 160
 161#ifdef CONFIG_DEBUG_PAGEALLOC
 162void kernel_map_pages(struct page *page, int numpages, int enable)
 163{
 164        pgd_t *pgd;
 165        pud_t *pud;
 166        pmd_t *pmd;
 167        pte_t *pte;
 168        unsigned long address;
 169        int i;
 170
 171        for (i = 0; i < numpages; i++) {
 172                address = page_to_phys(page + i);
 173                pgd = pgd_offset_k(address);
 174                pud = pud_offset(pgd, address);
 175                pmd = pmd_offset(pud, address);
 176                pte = pte_offset_kernel(pmd, address);
 177                if (!enable) {
 178                        ptep_invalidate(&init_mm, address, pte);
 179                        continue;
 180                }
 181                *pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
 182                /* Flush cpu write queue. */
 183                mb();
 184        }
 185}
 186#endif
 187
 188void free_init_pages(char *what, unsigned long begin, unsigned long end)
 189{
 190        unsigned long addr = begin;
 191
 192        if (begin >= end)
 193                return;
 194        for (; addr < end; addr += PAGE_SIZE) {
 195                ClearPageReserved(virt_to_page(addr));
 196                init_page_count(virt_to_page(addr));
 197                memset((void *)(addr & PAGE_MASK), POISON_FREE_INITMEM,
 198                       PAGE_SIZE);
 199                free_page(addr);
 200                totalram_pages++;
 201        }
 202        printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
 203}
 204
 205void free_initmem(void)
 206{
 207        free_init_pages("unused kernel memory",
 208                        (unsigned long)&__init_begin,
 209                        (unsigned long)&__init_end);
 210}
 211
 212#ifdef CONFIG_BLK_DEV_INITRD
 213void free_initrd_mem(unsigned long start, unsigned long end)
 214{
 215        free_init_pages("initrd memory", start, end);
 216}
 217#endif
 218
 219#ifdef CONFIG_MEMORY_HOTPLUG
 220int arch_add_memory(int nid, u64 start, u64 size)
 221{
 222        struct pglist_data *pgdat;
 223        struct zone *zone;
 224        int rc;
 225
 226        pgdat = NODE_DATA(nid);
 227        zone = pgdat->node_zones + ZONE_MOVABLE;
 228        rc = vmem_add_mapping(start, size);
 229        if (rc)
 230                return rc;
 231        rc = __add_pages(nid, zone, PFN_DOWN(start), PFN_DOWN(size));
 232        if (rc)
 233                vmem_remove_mapping(start, size);
 234        return rc;
 235}
 236#endif /* CONFIG_MEMORY_HOTPLUG */
 237