arch/x86/mm/pgtable_32.c

   1 #include <linux/sched.h>
   2 #include <linux/kernel.h>
   3 #include <linux/errno.h>
   4 #include <linux/mm.h>
   5 #include <linux/nmi.h>
   6 #include <linux/swap.h>
   7 #include <linux/smp.h>
   8 #include <linux/highmem.h>
   9 #include <linux/slab.h>
  10 #include <linux/pagemap.h>
  11 #include <linux/spinlock.h>
  12 #include <linux/module.h>
  13 #include <linux/quicklist.h>
  14
  15 #include <asm/system.h>
  16 #include <asm/pgtable.h>
  17 #include <asm/pgalloc.h>
  18 #include <asm/fixmap.h>
  19 #include <asm/e820.h>
  20 #include <asm/tlb.h>
  21 #include <asm/tlbflush.h>
  22
  23 void show_mem(void)
  24 {
  25         int total = 0, reserved = 0;
  26         int shared = 0, cached = 0;
  27         int highmem = 0;
  28         struct page *page;
  29         pg_data_t *pgdat;
  30         unsigned long i;
  31         unsigned long flags;
  32
  33         printk(KERN_INFO "Mem-info:\n");
  34         show_free_areas();
  35         for_each_online_pgdat(pgdat) {
  36                 pgdat_resize_lock(pgdat, &flags);
  37                 for (i = 0; i < pgdat->node_spanned_pages; ++i) {
  38                         if (unlikely(i % MAX_ORDER_NR_PAGES == 0))
  39                                 touch_nmi_watchdog();
  40                         page = pgdat_page_nr(pgdat, i);
  41                         total++;
  42                         if (PageHighMem(page))
  43                                 highmem++;
  44                         if (PageReserved(page))
  45                                 reserved++;
  46                         else if (PageSwapCache(page))
  47                                 cached++;
  48                         else if (page_count(page))
  49                                 shared += page_count(page) - 1;
  50                 }
  51                 pgdat_resize_unlock(pgdat, &flags);
  52         }
  53         printk(KERN_INFO "%d pages of RAM\n", total);
  54         printk(KERN_INFO "%d pages of HIGHMEM\n", highmem);
  55         printk(KERN_INFO "%d reserved pages\n", reserved);
  56         printk(KERN_INFO "%d pages shared\n", shared);
  57         printk(KERN_INFO "%d pages swap cached\n", cached);
  58
  59         printk(KERN_INFO "%lu pages dirty\n", global_page_state(NR_FILE_DIRTY));
  60         printk(KERN_INFO "%lu pages writeback\n",
  61                                         global_page_state(NR_WRITEBACK));
  62         printk(KERN_INFO "%lu pages mapped\n", global_page_state(NR_FILE_MAPPED));
  63         printk(KERN_INFO "%lu pages slab\n",
  64                 global_page_state(NR_SLAB_RECLAIMABLE) +
  65                 global_page_state(NR_SLAB_UNRECLAIMABLE));
  66         printk(KERN_INFO "%lu pages pagetables\n",
  67                                         global_page_state(NR_PAGETABLE));
  68 }
  69
  70 /*
  71  * Associate a virtual page frame with a given physical page frame
  72  * and protection flags for that frame.
  73  */
  74 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
  75 {
  76         pgd_t *pgd;
  77         pud_t *pud;
  78         pmd_t *pmd;
  79         pte_t *pte;
  80
  81         pgd = swapper_pg_dir + pgd_index(vaddr);
  82         if (pgd_none(*pgd)) {
  83                 BUG();
  84                 return;
  85         }
  86         pud = pud_offset(pgd, vaddr);
  87         if (pud_none(*pud)) {
  88                 BUG();
  89                 return;
  90         }
  91         pmd = pmd_offset(pud, vaddr);
  92         if (pmd_none(*pmd)) {
  93                 BUG();
  94                 return;
  95         }
  96         pte = pte_offset_kernel(pmd, vaddr);
  97         if (pte_val(pteval))
  98                 set_pte_present(&init_mm, vaddr, pte, pteval);
  99         else
 100                 pte_clear(&init_mm, vaddr, pte);
 101
 102         /*
 103          * It's enough to flush this one mapping.
 104          * (PGE mappings get flushed as well)
 105          */
 106         __flush_tlb_one(vaddr);
 107 }
 108
 109 /*
 110  * Associate a large virtual page frame with a given physical page frame
 111  * and protection flags for that frame. pfn is for the base of the page,
 112  * vaddr is what the page gets mapped to - both must be properly aligned.
 113  * The pmd must already be instantiated. Assumes PAE mode.
 114  */
 115 void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
 116 {
 117         pgd_t *pgd;
 118         pud_t *pud;
 119         pmd_t *pmd;
 120
 121         if (vaddr & (PMD_SIZE-1)) {             /* vaddr is misaligned */
 122                 printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
 123                 return; /* BUG(); */
 124         }
 125         if (pfn & (PTRS_PER_PTE-1)) {           /* pfn is misaligned */
 126                 printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
 127                 return; /* BUG(); */
 128         }
 129         pgd = swapper_pg_dir + pgd_index(vaddr);
 130         if (pgd_none(*pgd)) {
 131                 printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
 132                 return; /* BUG(); */
 133         }
 134         pud = pud_offset(pgd, vaddr);
 135         pmd = pmd_offset(pud, vaddr);
 136         set_pmd(pmd, pfn_pmd(pfn, flags));
 137         /*
 138          * It's enough to flush this one mapping.
 139          * (PGE mappings get flushed as well)
 140          */
 141         __flush_tlb_one(vaddr);
 142 }
 143
 144 unsigned long __FIXADDR_TOP = 0xfffff000;
 145 EXPORT_SYMBOL(__FIXADDR_TOP);
 146
 147 /**
 148  * reserve_top_address - reserves a hole in the top of kernel address space
 149  * @reserve - size of hole to reserve
 150  *
 151  * Can be used to relocate the fixmap area and poke a hole in the top
 152  * of kernel address space to make room for a hypervisor.
 153  */
 154 void __init reserve_top_address(unsigned long reserve)
 155 {
 156         BUG_ON(fixmaps_set > 0);
 157         printk(KERN_INFO "Reserving virtual address space above 0x%08x\n",
 158                (int)-reserve);
 159         __FIXADDR_TOP = -reserve - PAGE_SIZE;
 160         __VMALLOC_RESERVE += reserve;
 161 }
 162
 163 /*
 164  * vmalloc=size forces the vmalloc area to be exactly 'size'
 165  * bytes. This can be used to increase (or decrease) the
 166  * vmalloc area - the default is 128m.
 167  */
 168 static int __init parse_vmalloc(char *arg)
 169 {
 170         if (!arg)
 171                 return -EINVAL;
 172
 173         __VMALLOC_RESERVE = memparse(arg, &arg);
 174         return 0;
 175 }
 176 early_param("vmalloc", parse_vmalloc);
 177
 178 /*
 179  * reservetop=size reserves a hole at the top of the kernel address space which
 180  * a hypervisor can load into later.  Needed for dynamically loaded hypervisors,
 181  * so relocating the fixmap can be done before paging initialization.
 182  */
 183 static int __init parse_reservetop(char *arg)
 184 {
 185         unsigned long address;
 186
 187         if (!arg)
 188                 return -EINVAL;
 189
 190         address = memparse(arg, &arg);
 191         reserve_top_address(address);
 192         return 0;
 193 }
 194 early_param("reservetop", parse_reservetop);