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
  41 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  42
  43 unsigned long empty_zero_page, zero_page_mask;
  44 EXPORT_SYMBOL(empty_zero_page);
  45
  46 static 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  */
  92 void __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
 130 void __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
 162 void 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
 188 void 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
 205 void 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
 213 void 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
 220 int 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 */