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/pfn.h>
  25 #include <linux/poison.h>
  26 #include <linux/initrd.h>
  27 #include <linux/export.h>
  28 #include <linux/gfp.h>
  29 #include <asm/processor.h>
  30 #include <asm/uaccess.h>
  31 #include <asm/pgtable.h>
  32 #include <asm/pgalloc.h>
  33 #include <asm/dma.h>
  34 #include <asm/lowcore.h>
  35 #include <asm/tlb.h>
  36 #include <asm/tlbflush.h>
  37 #include <asm/sections.h>
  38 #include <asm/ctl_reg.h>
  39
  40 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  41
  42 unsigned long empty_zero_page, zero_page_mask;
  43 EXPORT_SYMBOL(empty_zero_page);
  44
  45 static unsigned long setup_zero_pages(void)
  46 {
  47         struct cpuid cpu_id;
  48         unsigned int order;
  49         unsigned long size;
  50         struct page *page;
  51         int i;
  52
  53         get_cpu_id(&cpu_id);
  54         switch (cpu_id.machine) {
  55         case 0x9672:    /* g5 */
  56         case 0x2064:    /* z900 */
  57         case 0x2066:    /* z900 */
  58         case 0x2084:    /* z990 */
  59         case 0x2086:    /* z990 */
  60         case 0x2094:    /* z9-109 */
  61         case 0x2096:    /* z9-109 */
  62                 order = 0;
  63                 break;
  64         case 0x2097:    /* z10 */
  65         case 0x2098:    /* z10 */
  66         default:
  67                 order = 2;
  68                 break;
  69         }
  70
  71         empty_zero_page = __get_free_pages(GFP_KERNEL | __GFP_ZERO, order);
  72         if (!empty_zero_page)
  73                 panic("Out of memory in setup_zero_pages");
  74
  75         page = virt_to_page((void *) empty_zero_page);
  76         split_page(page, order);
  77         for (i = 1 << order; i > 0; i--) {
  78                 SetPageReserved(page);
  79                 page++;
  80         }
  81
  82         size = PAGE_SIZE << order;
  83         zero_page_mask = (size - 1) & PAGE_MASK;
  84
  85         return 1UL << order;
  86 }
  87
  88 /*
  89  * paging_init() sets up the page tables
  90  */
  91 void __init paging_init(void)
  92 {
  93         unsigned long max_zone_pfns[MAX_NR_ZONES];
  94         unsigned long pgd_type, asce_bits;
  95
  96         init_mm.pgd = swapper_pg_dir;
  97 #ifdef CONFIG_64BIT
  98         if (VMALLOC_END > (1UL << 42)) {
  99                 asce_bits = _ASCE_TYPE_REGION2 | _ASCE_TABLE_LENGTH;
 100                 pgd_type = _REGION2_ENTRY_EMPTY;
 101         } else {
 102                 asce_bits = _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
 103                 pgd_type = _REGION3_ENTRY_EMPTY;
 104         }
 105 #else
 106         asce_bits = _ASCE_TABLE_LENGTH;
 107         pgd_type = _SEGMENT_ENTRY_EMPTY;
 108 #endif
 109         S390_lowcore.kernel_asce = (__pa(init_mm.pgd) & PAGE_MASK) | asce_bits;
 110         clear_table((unsigned long *) init_mm.pgd, pgd_type,
 111                     sizeof(unsigned long)*2048);
 112         vmem_map_init();
 113
 114         /* enable virtual mapping in kernel mode */
 115         __ctl_load(S390_lowcore.kernel_asce, 1, 1);
 116         __ctl_load(S390_lowcore.kernel_asce, 7, 7);
 117         __ctl_load(S390_lowcore.kernel_asce, 13, 13);
 118         arch_local_irq_restore(4UL << (BITS_PER_LONG - 8));
 119
 120         atomic_set(&init_mm.context.attach_count, 1);
 121
 122         sparse_memory_present_with_active_regions(MAX_NUMNODES);
 123         sparse_init();
 124         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
 125         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
 126         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
 127         free_area_init_nodes(max_zone_pfns);
 128         fault_init();
 129 }
 130
 131 void __init mem_init(void)
 132 {
 133         unsigned long codesize, reservedpages, datasize, initsize;
 134
 135         max_mapnr = num_physpages = max_low_pfn;
 136         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
 137
 138         /* Setup guest page hinting */
 139         cmma_init();
 140
 141         /* this will put all low memory onto the freelists */
 142         totalram_pages += free_all_bootmem();
 143         totalram_pages -= setup_zero_pages();   /* Setup zeroed pages. */
 144
 145         reservedpages = 0;
 146
 147         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 148         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 149         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 150         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 151                 nr_free_pages() << (PAGE_SHIFT-10),
 152                 max_mapnr << (PAGE_SHIFT-10),
 153                 codesize >> 10,
 154                 reservedpages << (PAGE_SHIFT-10),
 155                 datasize >>10,
 156                 initsize >> 10);
 157         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 158                (unsigned long)&_stext,
 159                PFN_ALIGN((unsigned long)&_eshared) - 1);
 160 }
 161
 162 #ifdef CONFIG_DEBUG_PAGEALLOC
 163 void kernel_map_pages(struct page *page, int numpages, int enable)
 164 {
 165         pgd_t *pgd;
 166         pud_t *pud;
 167         pmd_t *pmd;
 168         pte_t *pte;
 169         unsigned long address;
 170         int i;
 171
 172         for (i = 0; i < numpages; i++) {
 173                 address = page_to_phys(page + i);
 174                 pgd = pgd_offset_k(address);
 175                 pud = pud_offset(pgd, address);
 176                 pmd = pmd_offset(pud, address);
 177                 pte = pte_offset_kernel(pmd, address);
 178                 if (!enable) {
 179                         __ptep_ipte(address, pte);
 180                         pte_val(*pte) = _PAGE_TYPE_EMPTY;
 181                         continue;
 182                 }
 183                 *pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
 184                 /* Flush cpu write queue. */
 185                 mb();
 186         }
 187 }
 188 #endif
 189
 190 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 191 {
 192         unsigned long addr = begin;
 193
 194         if (begin >= end)
 195                 return;
 196         for (; addr < end; addr += PAGE_SIZE) {
 197                 ClearPageReserved(virt_to_page(addr));
 198                 init_page_count(virt_to_page(addr));
 199                 memset((void *)(addr & PAGE_MASK), POISON_FREE_INITMEM,
 200                        PAGE_SIZE);
 201                 free_page(addr);
 202                 totalram_pages++;
 203         }
 204         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
 205 }
 206
 207 void free_initmem(void)
 208 {
 209         free_init_pages("unused kernel memory",
 210                         (unsigned long)&__init_begin,
 211                         (unsigned long)&__init_end);
 212 }
 213
 214 #ifdef CONFIG_BLK_DEV_INITRD
 215 void free_initrd_mem(unsigned long start, unsigned long end)
 216 {
 217         free_init_pages("initrd memory", start, end);
 218 }
 219 #endif
 220
 221 #ifdef CONFIG_MEMORY_HOTPLUG
 222 int arch_add_memory(int nid, u64 start, u64 size)
 223 {
 224         unsigned long zone_start_pfn, zone_end_pfn, nr_pages;
 225         unsigned long start_pfn = PFN_DOWN(start);
 226         unsigned long size_pages = PFN_DOWN(size);
 227         struct zone *zone;
 228         int rc;
 229
 230         rc = vmem_add_mapping(start, size);
 231         if (rc)
 232                 return rc;
 233         for_each_zone(zone) {
 234                 if (zone_idx(zone) != ZONE_MOVABLE) {
 235                         /* Add range within existing zone limits */
 236                         zone_start_pfn = zone->zone_start_pfn;
 237                         zone_end_pfn = zone->zone_start_pfn +
 238                                        zone->spanned_pages;
 239                 } else {
 240                         /* Add remaining range to ZONE_MOVABLE */
 241                         zone_start_pfn = start_pfn;
 242                         zone_end_pfn = start_pfn + size_pages;
 243                 }
 244                 if (start_pfn < zone_start_pfn || start_pfn >= zone_end_pfn)
 245                         continue;
 246                 nr_pages = (start_pfn + size_pages > zone_end_pfn) ?
 247                            zone_end_pfn - start_pfn : size_pages;
 248                 rc = __add_pages(nid, zone, start_pfn, nr_pages);
 249                 if (rc)
 250                         break;
 251                 start_pfn += nr_pages;
 252                 size_pages -= nr_pages;
 253                 if (!size_pages)
 254                         break;
 255         }
 256         if (rc)
 257                 vmem_remove_mapping(start, size);
 258         return rc;
 259 }
 260 #endif /* CONFIG_MEMORY_HOTPLUG */