arch/s390/mm/init.c

   1 /*
   2  *  S390 version
   3  *    Copyright IBM Corp. 1999
   4  *    Author(s): Hartmut Penner (hp@de.ibm.com)
   5  *
   6  *  Derived from "arch/i386/mm/init.c"
   7  *    Copyright (C) 1995  Linus Torvalds
   8  */
   9
  10 #include <linux/signal.h>
  11 #include <linux/sched.h>
  12 #include <linux/kernel.h>
  13 #include <linux/errno.h>
  14 #include <linux/string.h>
  15 #include <linux/types.h>
  16 #include <linux/ptrace.h>
  17 #include <linux/mman.h>
  18 #include <linux/mm.h>
  19 #include <linux/swap.h>
  20 #include <linux/smp.h>
  21 #include <linux/init.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/bootmem.h>
  24 #include <linux/memory.h>
  25 #include <linux/pfn.h>
  26 #include <linux/poison.h>
  27 #include <linux/initrd.h>
  28 #include <linux/export.h>
  29 #include <linux/gfp.h>
  30 #include <asm/processor.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 #include <asm/ctl_reg.h>
  40 #include <asm/sclp.h>
  41
  42 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  43
  44 unsigned long empty_zero_page, zero_page_mask;
  45 EXPORT_SYMBOL(empty_zero_page);
  46
  47 static void __init setup_zero_pages(void)
  48 {
  49         struct cpuid cpu_id;
  50         unsigned int order;
  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         case 0x2817:    /* z196 */
  68         case 0x2818:    /* z196 */
  69                 order = 2;
  70                 break;
  71         case 0x2827:    /* zEC12 */
  72         default:
  73                 order = 5;
  74                 break;
  75         }
  76         /* Limit number of empty zero pages for small memory sizes */
  77         if (order > 2 && totalram_pages <= 16384)
  78                 order = 2;
  79
  80         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  81         if (!empty_zero_page)
  82                 panic("Out of memory in setup_zero_pages");
  83
  84         page = virt_to_page((void *) empty_zero_page);
  85         split_page(page, order);
  86         for (i = 1 << order; i > 0; i--) {
  87                 mark_page_reserved(page);
  88                 page++;
  89         }
  90
  91         zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
  92 }
  93
  94 /*
  95  * paging_init() sets up the page tables
  96  */
  97 void __init paging_init(void)
  98 {
  99         unsigned long max_zone_pfns[MAX_NR_ZONES];
 100         unsigned long pgd_type, asce_bits;
 101
 102         init_mm.pgd = swapper_pg_dir;
 103 #ifdef CONFIG_64BIT
 104         if (VMALLOC_END > (1UL << 42)) {
 105                 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
 106                 pgd_type = _REGION2_ENTRY_EMPTY;
 107         } else {
 108                 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
 109                 pgd_type = _REGION3_ENTRY_EMPTY;
 110         }
 111 #else
 112         asce_bits = _ASCE_TABLE_LENGTH;
 113         pgd_type = _SEGMENT_ENTRY_EMPTY;
 114 #endif
 115         S390_lowcore.kernel_asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
 116         clear_table((unsigned long *) init_mm.pgd, pgd_type,
 117                     sizeof(unsigned long)*2048);
 118         vmem_map_init();
 119
 120         /* enable virtual mapping in kernel mode */
 121         __ctl_load(S390_lowcore.kernel_asce, 1, 1);
 122         __ctl_load(S390_lowcore.kernel_asce, 7, 7);
 123         __ctl_load(S390_lowcore.kernel_asce, 13, 13);
 124         arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));
 125
 126         atomic_set(&init_mm.context.attach_count, 1);
 127
 128         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 129         sparse_init();
 130         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 131         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 132         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 133         free_area_init_nodes(max_zone_pfns);
 134 }
 135
 136 void __init mem_init(void)
 137 {
 138         max_mapnr = max_low_pfn;
 139         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 140
 141         /* Setup guest page hinting */
 142         cmma_init();
 143
 144         /* this will put all low memory onto the freelists */
 145         free_all_bootmem();
 146         setup_zero_pages();     /* Setup zeroed pages. */
 147
 148         mem_init_print_info(NULL);
 149         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 150                (unsigned long)&_stext,
 151                PFN_ALIGN((unsigned long)&_eshared) - 1);
 152 }
 153
 154 void free_initmem(void)
 155 {
 156         free_initmem_default(POISON_FREE_INITMEM);
 157 }
 158
 159 #ifdef CONFIG_BLK_DEV_INITRD
 160 void __init free_initrd_mem(unsigned long start, unsigned long end)
 161 {
 162         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 163                            "initrd");
 164 }
 165 #endif
 166
 167 #ifdef CONFIG_MEMORY_HOTPLUG
 168 int arch_add_memory(int nid, u64 start, u64 size)
 169 {
 170         unsigned long zone_start_pfn, zone_end_pfn, nr_pages;
 171         unsigned long start_pfn = PFN_DOWN(start);
 172         unsigned long size_pages = PFN_DOWN(size);
 173         struct zone *zone;
 174         int rc;
 175
 176         rc = vmem_add_mapping(start, size);
 177         if (rc)
 178                 return rc;
 179         for_each_zone(zone) {
 180                 if (zone_idx(zone) != ZONE_MOVABLE) {
 181                         /* Add range within existing zone limits */
 182                         zone_start_pfn = zone->zone_start_pfn;
 183                         zone_end_pfn = zone->zone_start_pfn +
 184                                        zone->spanned_pages;
 185                 } else {
 186                         /* Add remaining range to ZONE_MOVABLE */
 187                         zone_start_pfn = start_pfn;
 188                         zone_end_pfn = start_pfn + size_pages;
 189                 }
 190                 if (start_pfn < zone_start_pfn || start_pfn >= zone_end_pfn)
 191                         continue;
 192                 nr_pages = (start_pfn + size_pages > zone_end_pfn) ?
 193                            zone_end_pfn - start_pfn : size_pages;
 194                 rc = __add_pages(nid, zone, start_pfn, nr_pages);
 195                 if (rc)
 196                         break;
 197                 start_pfn += nr_pages;
 198                 size_pages -= nr_pages;
 199                 if (!size_pages)
 200                         break;
 201         }
 202         if (rc)
 203                 vmem_remove_mapping(start, size);
 204         return rc;
 205 }
 206
 207 unsigned long memory_block_size_bytes(void)
 208 {
 209         /*
 210          * Make sure the memory block size is always greater
 211          * or equal than the memory increment size.
 212          */
 213         return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp_get_rzm());
 214 }
 215
 216 #ifdef CONFIG_MEMORY_HOTREMOVE
 217 int arch_remove_memory(u64 start, u64 size)
 218 {
 219         /*
 220          * There is no hardware or firmware interface which could trigger a
 221          * hot memory remove on s390. So there is nothing that needs to be
 222          * implemented.
 223          */
 224         return -EBUSY;
 225 }
 226 #endif
 227 #endif /* CONFIG_MEMORY_HOTPLUG */