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/pagemap.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/module.h>
  12
  13 #include <asm/system.h>
  14 #include <asm/pgtable.h>
  15 #include <asm/pgalloc.h>
  16 #include <asm/fixmap.h>
  17 #include <asm/e820.h>
  18 #include <asm/tlb.h>
  19 #include <asm/tlbflush.h>
  20 #include <asm/io.h>
  21
  22 unsigned int __VMALLOC_RESERVE = 128 << 20;
  23
  24 /*
  25  * Associate a virtual page frame with a given physical page frame
  26  * and protection flags for that frame.
  27  */
  28 void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
  29 {
  30         pgd_t *pgd;
  31         pud_t *pud;
  32         pmd_t *pmd;
  33         pte_t *pte;
  34
  35         pgd = swapper_pg_dir + pgd_index(vaddr);
  36         if (pgd_none(*pgd)) {
  37                 BUG();
  38                 return;
  39         }
  40         pud = pud_offset(pgd, vaddr);
  41         if (pud_none(*pud)) {
  42                 BUG();
  43                 return;
  44         }
  45         pmd = pmd_offset(pud, vaddr);
  46         if (pmd_none(*pmd)) {
  47                 BUG();
  48                 return;
  49         }
  50         pte = pte_offset_kernel(pmd, vaddr);
  51         if (pte_val(pteval))
  52                 set_pte_at(&init_mm, vaddr, pte, pteval);
  53         else
  54                 pte_clear(&init_mm, vaddr, pte);
  55
  56         /*
  57          * It's enough to flush this one mapping.
  58          * (PGE mappings get flushed as well)
  59          */
  60         __flush_tlb_one(vaddr);
  61 }
  62
  63 /*
  64  * Associate a large virtual page frame with a given physical page frame
  65  * and protection flags for that frame. pfn is for the base of the page,
  66  * vaddr is what the page gets mapped to - both must be properly aligned.
  67  * The pmd must already be instantiated. Assumes PAE mode.
  68  */
  69 void set_pmd_pfn(unsigned long vaddr, unsigned long pfn, pgprot_t flags)
  70 {
  71         pgd_t *pgd;
  72         pud_t *pud;
  73         pmd_t *pmd;
  74
  75         if (vaddr & (PMD_SIZE-1)) {             /* vaddr is misaligned */
  76                 printk(KERN_WARNING "set_pmd_pfn: vaddr misaligned\n");
  77                 return; /* BUG(); */
  78         }
  79         if (pfn & (PTRS_PER_PTE-1)) {           /* pfn is misaligned */
  80                 printk(KERN_WARNING "set_pmd_pfn: pfn misaligned\n");
  81                 return; /* BUG(); */
  82         }
  83         pgd = swapper_pg_dir + pgd_index(vaddr);
  84         if (pgd_none(*pgd)) {
  85                 printk(KERN_WARNING "set_pmd_pfn: pgd_none\n");
  86                 return; /* BUG(); */
  87         }
  88         pud = pud_offset(pgd, vaddr);
  89         pmd = pmd_offset(pud, vaddr);
  90         set_pmd(pmd, pfn_pmd(pfn, flags));
  91         /*
  92          * It's enough to flush this one mapping.
  93          * (PGE mappings get flushed as well)
  94          */
  95         __flush_tlb_one(vaddr);
  96 }
  97
  98 unsigned long __FIXADDR_TOP = 0xfffff000;
  99 EXPORT_SYMBOL(__FIXADDR_TOP);
 100
 101 /*
 102  * vmalloc=size forces the vmalloc area to be exactly 'size'
 103  * bytes. This can be used to increase (or decrease) the
 104  * vmalloc area - the default is 128m.
 105  */
 106 static int __init parse_vmalloc(char *arg)
 107 {
 108         if (!arg)
 109                 return -EINVAL;
 110
 111         /* Add VMALLOC_OFFSET to the parsed value due to vm area guard hole*/
 112         __VMALLOC_RESERVE = memparse(arg, &arg) + VMALLOC_OFFSET;
 113         return 0;
 114 }
 115 early_param("vmalloc", parse_vmalloc);
 116
 117 /*
 118  * reservetop=size reserves a hole at the top of the kernel address space which
 119  * a hypervisor can load into later.  Needed for dynamically loaded hypervisors,
 120  * so relocating the fixmap can be done before paging initialization.
 121  */
 122 static int __init parse_reservetop(char *arg)
 123 {
 124         unsigned long address;
 125
 126         if (!arg)
 127                 return -EINVAL;
 128
 129         address = memparse(arg, &arg);
 130         reserve_top_address(address);
 131         fixup_early_ioremap();
 132         return 0;
 133 }
 134 early_param("reservetop", parse_reservetop);