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