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 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  42
  43 pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
  44
  45 char  empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
  46 EXPORT_SYMBOL(empty_zero_page);
  47
  48 /*
  49  * paging_init() sets up the page tables
  50  */
  51 void __init paging_init(void)
  52 {
  53         static const int ssm_mask = 0x04000000L;
  54         unsigned long max_zone_pfns[MAX_NR_ZONES];
  55         unsigned long pgd_type;
  56
  57         init_mm.pgd = swapper_pg_dir;
  58         S390_lowcore.kernel_asce = __pa(init_mm.pgd) & PAGE_MASK;
  59 #ifdef CONFIG_64BIT
  60         /* A three level page table (4TB) is enough for the kernel space. */
  61         S390_lowcore.kernel_asce |= _ASCE_TYPE_REGION3 | _ASCE_TABLE_LENGTH;
  62         pgd_type = _REGION3_ENTRY_EMPTY;
  63 #else
  64         S390_lowcore.kernel_asce |= _ASCE_TABLE_LENGTH;
  65         pgd_type = _SEGMENT_ENTRY_EMPTY;
  66 #endif
  67         clear_table((unsigned long *) init_mm.pgd, pgd_type,
  68                     sizeof(unsigned long)*2048);
  69         vmem_map_init();
  70
  71         /* enable virtual mapping in kernel mode */
  72         __ctl_load(S390_lowcore.kernel_asce, 1, 1);
  73         __ctl_load(S390_lowcore.kernel_asce, 7, 7);
  74         __ctl_load(S390_lowcore.kernel_asce, 13, 13);
  75         __raw_local_irq_ssm(ssm_mask);
  76
  77         atomic_set(&init_mm.context.attach_count, 1);
  78
  79         sparse_memory_present_with_active_regions(MAX_NUMNODES);
  80         sparse_init();
  81         memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
  82 #ifdef CONFIG_ZONE_DMA
  83         max_zone_pfns[ZONE_DMA] = PFN_DOWN(MAX_DMA_ADDRESS);
  84 #endif
  85         max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
  86         free_area_init_nodes(max_zone_pfns);
  87 }
  88
  89 void __init mem_init(void)
  90 {
  91         unsigned long codesize, reservedpages, datasize, initsize;
  92
  93         max_mapnr = num_physpages = max_low_pfn;
  94         high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
  95
  96         /* clear the zero-page */
  97         memset(empty_zero_page, 0, PAGE_SIZE);
  98
  99         /* Setup guest page hinting */
 100         cmma_init();
 101
 102         /* this will put all low memory onto the freelists */
 103         totalram_pages += free_all_bootmem();
 104
 105         reservedpages = 0;
 106
 107         codesize =  (unsigned long) &_etext - (unsigned long) &_text;
 108         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 109         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 110         printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
 111                 nr_free_pages() << (PAGE_SHIFT-10),
 112                 max_mapnr << (PAGE_SHIFT-10),
 113                 codesize >> 10,
 114                 reservedpages << (PAGE_SHIFT-10),
 115                 datasize >>10,
 116                 initsize >> 10);
 117         printk("Write protected kernel read-only data: %#lx - %#lx\n",
 118                (unsigned long)&_stext,
 119                PFN_ALIGN((unsigned long)&_eshared) - 1);
 120 }
 121
 122 #ifdef CONFIG_DEBUG_PAGEALLOC
 123 void kernel_map_pages(struct page *page, int numpages, int enable)
 124 {
 125         pgd_t *pgd;
 126         pud_t *pud;
 127         pmd_t *pmd;
 128         pte_t *pte;
 129         unsigned long address;
 130         int i;
 131
 132         for (i = 0; i < numpages; i++) {
 133                 address = page_to_phys(page + i);
 134                 pgd = pgd_offset_k(address);
 135                 pud = pud_offset(pgd, address);
 136                 pmd = pmd_offset(pud, address);
 137                 pte = pte_offset_kernel(pmd, address);
 138                 if (!enable) {
 139                         ptep_invalidate(&init_mm, address, pte);
 140                         continue;
 141                 }
 142                 *pte = mk_pte_phys(address, __pgprot(_PAGE_TYPE_RW));
 143                 /* Flush cpu write queue. */
 144                 mb();
 145         }
 146 }
 147 #endif
 148
 149 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 150 {
 151         unsigned long addr = begin;
 152
 153         if (begin >= end)
 154                 return;
 155         for (; addr < end; addr += PAGE_SIZE) {
 156                 ClearPageReserved(virt_to_page(addr));
 157                 init_page_count(virt_to_page(addr));
 158                 memset((void *)(addr & PAGE_MASK), POISON_FREE_INITMEM,
 159                        PAGE_SIZE);
 160                 free_page(addr);
 161                 totalram_pages++;
 162         }
 163         printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
 164 }
 165
 166 void free_initmem(void)
 167 {
 168         free_init_pages("unused kernel memory",
 169                         (unsigned long)&__init_begin,
 170                         (unsigned long)&__init_end);
 171 }
 172
 173 #ifdef CONFIG_BLK_DEV_INITRD
 174 void free_initrd_mem(unsigned long start, unsigned long end)
 175 {
 176         free_init_pages("initrd memory", start, end);
 177 }
 178 #endif
 179
 180 #ifdef CONFIG_MEMORY_HOTPLUG
 181 int arch_add_memory(int nid, u64 start, u64 size)
 182 {
 183         struct pglist_data *pgdat;
 184         struct zone *zone;
 185         int rc;
 186
 187         pgdat = NODE_DATA(nid);
 188         zone = pgdat->node_zones + ZONE_MOVABLE;
 189         rc = vmem_add_mapping(start, size);
 190         if (rc)
 191                 return rc;
 192         rc = __add_pages(nid, zone, PFN_DOWN(start), PFN_DOWN(size));
 193         if (rc)
 194                 vmem_remove_mapping(start, size);
 195         return rc;
 196 }
 197 #endif /* CONFIG_MEMORY_HOTPLUG */