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 <linux/memblock.h>
  31 #include <asm/processor.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 #include <asm/ctl_reg.h>
  41 #include <asm/sclp.h>
  42
  43 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  44
  45 unsigned long empty_zero_page, zero_page_mask;
  46 EXPORT_SYMBOL(empty_zero_page);
  47 EXPORT_SYMBOL(zero_page_mask);
  48
  49 static void __init setup_zero_pages(void)
  50 {
  51         struct cpuid cpu_id;
  52         unsigned int order;
  53         struct page *page;
  54         int i;
  55
  56         get_cpu_id(&cpu_id);
  57         switch (cpu_id.machine) {
  58         case 0x9672:    /* g5 */
  59         case 0x2064:    /* z900 */
  60         case 0x2066:    /* z900 */
  61         case 0x2084:    /* z990 */
  62         case 0x2086:    /* z990 */
  63         case 0x2094:    /* z9-109 */
  64         case 0x2096:    /* z9-109 */
  65                 order = 0;
  66                 break;
  67         case 0x2097:    /* z10 */
  68         case 0x2098:    /* z10 */
  69         case 0x2817:    /* z196 */
  70         case 0x2818:    /* z196 */
  71                 order = 2;
  72                 break;
  73         case 0x2827:    /* zEC12 */
  74         case 0x2828:    /* zEC12 */
  75                 order = 5;
  76                 break;
  77         case 0x2964:    /* z13 */
  78         default:
  79                 order = 7;
  80                 break;
  81         }
  82         /* Limit number of empty zero pages for small memory sizes */
  83         while (order > 2 && (totalram_pages >> 10) < (1UL << order))
  84                 order--;
  85
  86         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  87         if (!empty_zero_page)
  88                 panic("Out of memory in setup_zero_pages");
  89
  90         page = virt_to_page((void *) empty_zero_page);
  91         split_page(page, order);
  92         for (i = 1 << order; i > 0; i--) {
  93                 mark_page_reserved(page);
  94                 page++;
  95         }
  96
  97         zero_page_mask = ((PAGE_SIZE << order) - 1) & PAGE_MASK;
  98 }
  99
 100 /*
 101  * paging_init() sets up the page tables
 102  */
 103 void __init paging_init(void)
 104 {
 105         unsigned long max_zone_pfns[MAX_NR_ZONES];
 106         unsigned long pgd_type, asce_bits;
 107
 108         init_mm.pgd = swapper_pg_dir;
 109         if (VMALLOC_END > (1UL << 42)) {
 110                 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
 111                 pgd_type = _REGION2_ENTRY_EMPTY;
 112         } else {
 113                 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
 114                 pgd_type = _REGION3_ENTRY_EMPTY;
 115         }
 116         S390_lowcore.kernel_asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
 117         clear_table((unsigned long *) init_mm.pgd, pgd_type,
 118                     sizeof(unsigned long)*2048);
 119         vmem_map_init();
 120
 121         /* enable virtual mapping in kernel mode */
 122         __ctl_load(S390_lowcore.kernel_asce, 1, 1);
 123         __ctl_load(S390_lowcore.kernel_asce, 7, 7);
 124         __ctl_load(S390_lowcore.kernel_asce, 13, 13);
 125         arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));
 126
 127         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 128         sparse_init();
 129         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 130         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 131         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 132         free_area_init_nodes(max_zone_pfns);
 133 }
 134
 135 void __init mem_init(void)
 136 {
 137         if (MACHINE_HAS_TLB_LC)
 138                 cpumask_set_cpu(0, &init_mm.context.cpu_attach_mask);
 139         cpumask_set_cpu(0, mm_cpumask(&init_mm));
 140         atomic_set(&init_mm.context.attach_count, 1);
 141
 142         set_max_mapnr(max_low_pfn);
 143         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 144
 145         /* Setup guest page hinting */
 146         cmma_init();
 147
 148         /* this will put all low memory onto the freelists */
 149         free_all_bootmem();
 150         setup_zero_pages();     /* Setup zeroed pages. */
 151
 152         mem_init_print_info(NULL);
 153         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 154                (unsigned long)&_stext,
 155                PFN_ALIGN((unsigned long)&_eshared) - 1);
 156 }
 157
 158 void free_initmem(void)
 159 {
 160         free_initmem_default(POISON_FREE_INITMEM);
 161 }
 162
 163 #ifdef CONFIG_BLK_DEV_INITRD
 164 void __init free_initrd_mem(unsigned long start, unsigned long end)
 165 {
 166         free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 167                            "initrd");
 168 }
 169 #endif
 170
 171 #ifdef CONFIG_MEMORY_HOTPLUG
 172 int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
 173 {
 174         unsigned long normal_end_pfn = PFN_DOWN(memblock_end_of_DRAM());
 175         unsigned long dma_end_pfn = PFN_DOWN(MAX_DMA_ADDRESS);
 176         unsigned long start_pfn = PFN_DOWN(start);
 177         unsigned long size_pages = PFN_DOWN(size);
 178         unsigned long nr_pages;
 179         int rc, zone_enum;
 180
 181         rc = vmem_add_mapping(start, size);
 182         if (rc)
 183                 return rc;
 184
 185         while (size_pages > 0) {
 186                 if (start_pfn < dma_end_pfn) {
 187                         nr_pages = (start_pfn + size_pages > dma_end_pfn) ?
 188                                    dma_end_pfn - start_pfn : size_pages;
 189                         zone_enum = ZONE_DMA;
 190                 } else if (start_pfn < normal_end_pfn) {
 191                         nr_pages = (start_pfn + size_pages > normal_end_pfn) ?
 192                                    normal_end_pfn - start_pfn : size_pages;
 193                         zone_enum = ZONE_NORMAL;
 194                 } else {
 195                         nr_pages = size_pages;
 196                         zone_enum = ZONE_MOVABLE;
 197                 }
 198                 rc = __add_pages(nid, NODE_DATA(nid)->node_zones + zone_enum,
 199                                  start_pfn, size_pages);
 200                 if (rc)
 201                         break;
 202                 start_pfn += nr_pages;
 203                 size_pages -= nr_pages;
 204         }
 205         if (rc)
 206                 vmem_remove_mapping(start, size);
 207         return rc;
 208 }
 209
 210 unsigned long memory_block_size_bytes(void)
 211 {
 212         /*
 213          * Make sure the memory block size is always greater
 214          * or equal than the memory increment size.
 215          */
 216         return max_t(unsigned long, MIN_MEMORY_BLOCK_SIZE, sclp.rzm);
 217 }
 218
 219 #ifdef CONFIG_MEMORY_HOTREMOVE
 220 int arch_remove_memory(u64 start, u64 size)
 221 {
 222         /*
 223          * There is no hardware or firmware interface which could trigger a
 224          * hot memory remove on s390. So there is nothing that needs to be
 225          * implemented.
 226          */
 227         return -EBUSY;
 228 }
 229 #endif
 230 #endif /* CONFIG_MEMORY_HOTPLUG */