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 unsigned int __VMALLOC_RESERVE = 128 << 20;
  24
  25 /*
  26  * Associate a virtual page frame with a given physical page frame
  27  * and protection flags for that frame.
  28  */
  29 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
  30 {
  31         pgd_t *pgd;
  32         pud_t *pud;
  33         pmd_t *pmd;
  34         pte_t *pte;
  35
  36         pgd = swapper_pg_dir + pgd_index(vaddr);
  37         if (pgd_none(*pgd)) {
  38                 BUG();
  39                 return;
  40         }
  41         pud = pud_offset(pgd, vaddr);
  42         if (pud_none(*pud)) {
  43                 BUG();
  44                 return;
  45         }
  46         pmd = pmd_offset(pud, vaddr);
  47         if (pmd_none(*pmd)) {
  48                 BUG();
  49                 return;
  50         }
  51         pte = pte_offset_kernel(pmd, vaddr);
  52         if (pte_val(pteval))
  53                 set_pte_at(&init_mm, vaddr, pte, pteval);
  54         else
  55                 pte_clear(&init_mm, vaddr, pte);
  56
  57         /*
  58          * It's enough to flush this one mapping.
  59          * (PGE mappings get flushed as well)
  60          */
  61         __flush_tlb_one(vaddr);
  62 }
  63
  64 /*
  65  * Associate a large virtual page frame with a given physical page frame
  66  * and protection flags for that frame. pfn is for the base of the page,
  67  * vaddr is what the page gets mapped to - both must be properly aligned.
  68  * The pmd must already be instantiated. Assumes PAE mode.
  69  */
  70 void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
  71 {
  72         pgd_t *pgd;
  73         pud_t *pud;
  74         pmd_t *pmd;
  75
  76         if (vaddr & (PMD_SIZE-1)) {             /* vaddr is misaligned */
  77                 printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
  78                 return; /* BUG(); */
  79         }
  80         if (pfn & (PTRS_PER_PTE-1)) {           /* pfn is misaligned */
  81                 printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
  82                 return; /* BUG(); */
  83         }
  84         pgd = swapper_pg_dir + pgd_index(vaddr);
  85         if (pgd_none(*pgd)) {
  86                 printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
  87                 return; /* BUG(); */
  88         }
  89         pud = pud_offset(pgd, vaddr);
  90         pmd = pmd_offset(pud, vaddr);
  91         set_pmd(pmd, pfn_pmd(pfn, flags));
  92         /*
  93          * It's enough to flush this one mapping.
  94          * (PGE mappings get flushed as well)
  95          */
  96         __flush_tlb_one(vaddr);
  97 }
  98
  99 unsigned long __FIXADDR_TOP = 0xfffff000;
 100 EXPORT_SYMBOL(__FIXADDR_TOP);
 101
 102 /*
 103  * vmalloc=size forces the vmalloc area to be exactly 'size'
 104  * bytes. This can be used to increase (or decrease) the
 105  * vmalloc area - the default is 128m.
 106  */
 107 static int __init parse_vmalloc(char *arg)
 108 {
 109         if (!arg)
 110                 return -EINVAL;
 111
 112         /* Add VMALLOC_OFFSET to the parsed value due to vm area guard hole*/
 113         __VMALLOC_RESERVE = memparse(arg, &arg) + VMALLOC_OFFSET;
 114         return 0;
 115 }
 116 early_param("vmalloc", parse_vmalloc);
 117
 118 /*
 119  * reservetop=size reserves a hole at the top of the kernel address space which
 120  * a hypervisor can load into later.  Needed for dynamically loaded hypervisors,
 121  * so relocating the fixmap can be done before paging initialization.
 122  */
 123 static int __init parse_reservetop(char *arg)
 124 {
 125         unsigned long address;
 126
 127         if (!arg)
 128                 return -EINVAL;
 129
 130         address = memparse(arg, &arg);
 131         reserve_top_address(address);
 132         return 0;
 133 }
 134 early_param("reservetop", parse_reservetop);