linux/arch/s390/mm/init.c
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   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 <asm/processor.h>
  30#include <asm/system.h>
  31#include <asm/uaccess.h>
  32#include <asm/pgtable.h>
  33#include <asm/pgalloc.h>
  34#include <asm/dma.h>
  35#include <asm/lowcore.h>
  36#include <asm/tlb.h>
  37#include <asm/tlbflush.h>
  38#include <asm/sections.h>
  39
  40DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  41
  42pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  43char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
  44
  45/*
  46 * paging_init() sets up the page tables
  47 */
  48void __init paging_init(void)
  49{
  50        static const int ssm_mask = 0x04000000L;
  51        unsigned long max_zone_pfns[MAX_NR_ZONES];
  52        unsigned long pgd_type;
  53
  54        init_mm.pgd = swapper_pg_dir;
  55        S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
  56#ifdef CONFIG_64BIT
  57        /* A three level page table (4TB) is enough for the kernel space. */
  58        S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
  59        pgd_type = _REGION3_ENTRY_EMPTY;
  60#else
  61        S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
  62        pgd_type = _SEGMENT_ENTRY_EMPTY;
  63#endif
  64        clear_table((unsigned long *) init_mm.pgd, pgd_type,
  65                    sizeof(unsigned long)*2048);
  66        vmem_map_init();
  67
  68        /* enable virtual mapping in kernel mode */
  69        __ctl_load(S390_lowcore.kernel_asce, 1, 1);
  70        __ctl_load(S390_lowcore.kernel_asce, 7, 7);
  71        __ctl_load(S390_lowcore.kernel_asce, 13, 13);
  72        __raw_local_irq_ssm(ssm_mask);
  73
  74        sparse_memory_present_with_active_regions(MAX_NUMNODES);
  75        sparse_init();
  76        memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
  77#ifdef CONFIG_ZONE_DMA
  78        max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
  79#endif
  80        max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
  81        free_area_init_nodes(max_zone_pfns);
  82}
  83
  84void __init mem_init(void)
  85{
  86        unsigned long codesize, reservedpages, datasize, initsize;
  87
  88        max_mapnr = num_physpages = max_low_pfn;
  89        high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
  90
  91        /* clear the zero-page */
  92        memset(empty_zero_page, 0, PAGE_SIZE);
  93
  94        /* Setup guest page hinting */
  95        cmma_init();
  96
  97        /* this will put all low memory onto the freelists */
  98        totalram_pages += free_all_bootmem();
  99
 100        reservedpages = 0;
 101
 102        codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 103        datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 104        initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 105        printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 106                (unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 107                max_mapnr << (PAGE_SHIFT-10),
 108                codesize >> 10,
 109                reservedpages << (PAGE_SHIFT-10),
 110                datasize >>10,
 111                initsize >> 10);
 112        printk("Write protected kernel read-only data: %#lx - %#lx\n",
 113               (unsigned long)&_stext,
 114               PFN_ALIGN((unsigned long)&_eshared) - 1);
 115}
 116
 117#ifdef CONFIG_DEBUG_PAGEALLOC
 118void kernel_map_pages(struct page *page, int numpages, int enable)
 119{
 120        pgd_t *pgd;
 121        pud_t *pud;
 122        pmd_t *pmd;
 123        pte_t *pte;
 124        unsigned long address;
 125        int i;
 126
 127        for (i = 0; i < numpages; i++) {
 128                address = page_to_phys(page + i);
 129                pgd = pgd_offset_k(address);
 130                pud = pud_offset(pgd, address);
 131                pmd = pmd_offset(pud, address);
 132                pte = pte_offset_kernel(pmd, address);
 133                if (!enable) {
 134                        ptep_invalidate(&init_mm, address, pte);
 135                        continue;
 136                }
 137                *pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
 138                /* Flush cpu write queue. */
 139                mb();
 140        }
 141}
 142#endif
 143
 144void free_initmem(void)
 145{
 146        unsigned long addr;
 147
 148        addr = (unsigned long)(&__init_begin);
 149        for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
 150                ClearPageReserved(virt_to_page(addr));
 151                init_page_count(virt_to_page(addr));
 152                memset((void *)addr, POISON_FREE_INITMEM, PAGE_SIZE);
 153                free_page(addr);
 154                totalram_pages++;
 155        }
 156        printk ("Freeing unused kernel memory: %ldk freed\n",
 157                ((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
 158}
 159
 160#ifdef CONFIG_BLK_DEV_INITRD
 161void free_initrd_mem(unsigned long start, unsigned long end)
 162{
 163        if (start < end)
 164                printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
 165        for (; start < end; start += PAGE_SIZE) {
 166                ClearPageReserved(virt_to_page(start));
 167                init_page_count(virt_to_page(start));
 168                free_page(start);
 169                totalram_pages++;
 170        }
 171}
 172#endif
 173
 174#ifdef CONFIG_MEMORY_HOTPLUG
 175int arch_add_memory(int nid, u64 start, u64 size)
 176{
 177        struct pglist_data *pgdat;
 178        struct zone *zone;
 179        int rc;
 180
 181        pgdat = NODE_DATA(nid);
 182        zone = pgdat->node_zones + ZONE_MOVABLE;
 183        rc = vmem_add_mapping(start, size);
 184        if (rc)
 185                return rc;
 186        rc = __add_pages(zone, PFN_DOWN(start), PFN_DOWN(size));
 187        if (rc)
 188                vmem_remove_mapping(start, size);
 189        return rc;
 190}
 191#endif /* CONFIG_MEMORY_HOTPLUG */
 192
 193#ifdef CONFIG_MEMORY_HOTREMOVE
 194int remove_memory(u64 start, u64 size)
 195{
 196        unsigned long start_pfn, end_pfn;
 197
 198        start_pfn = PFN_DOWN(start);
 199        end_pfn = start_pfn + PFN_DOWN(size);
 200        return offline_pages(start_pfn, end_pfn, 120 * HZ);
 201}
 202#endif /* CONFIG_MEMORY_HOTREMOVE */
 203