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 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
  44
  45 /*
  46  * paging_init() sets up the page tables
  47  */
  48 void __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
  84 void __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
 118 void 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
 144 void 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
 161 void 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
 175 int 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
 194 int 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 */