LXR linux/arch/x86/mm/pgtable

   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/pgtable.h>
  14#include <asm/pgalloc.h>
  15#include <asm/fixmap.h>
  16#include <asm/e820.h>
  17#include <asm/tlb.h>
  18#include <asm/tlbflush.h>
  19#include <asm/io.h>
  20
  21unsigned int __VMALLOC_RESERVE = 128 << 20;
  22
  23/*
  24 * Associate a virtual page frame with a given physical page frame 
  25 * and protection flags for that frame.
  26 */ 
  27void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
  28{
  29        pgd_t *pgd;
  30        pud_t *pud;
  31        pmd_t *pmd;
  32        pte_t *pte;
  33
  34        pgd = swapper_pg_dir + pgd_index(vaddr);
  35        if (pgd_none(*pgd)) {
  36                BUG();
  37                return;
  38        }
  39        pud = pud_offset(pgd, vaddr);
  40        if (pud_none(*pud)) {
  41                BUG();
  42                return;
  43        }
  44        pmd = pmd_offset(pud, vaddr);
  45        if (pmd_none(*pmd)) {
  46                BUG();
  47                return;
  48        }
  49        pte = pte_offset_kernel(pmd, vaddr);
  50        if (pte_val(pteval))
  51                set_pte_at(&init_mm, vaddr, pte, pteval);
  52        else
  53                pte_clear(&init_mm, vaddr, pte);
  54
  55        /*
  56         * It's enough to flush this one mapping.
  57         * (PGE mappings get flushed as well)
  58         */
  59        __flush_tlb_one(vaddr);
  60}
  61
  62unsigned long __FIXADDR_TOP = 0xfffff000;
  63EXPORT_SYMBOL(__FIXADDR_TOP);
  64
  65/*
  66 * vmalloc=size forces the vmalloc area to be exactly 'size'
  67 * bytes. This can be used to increase (or decrease) the
  68 * vmalloc area - the default is 128m.
  69 */
  70static int __init parse_vmalloc(char *arg)
  71{
  72        if (!arg)
  73                return -EINVAL;
  74
  75        /* Add VMALLOC_OFFSET to the parsed value due to vm area guard hole*/
  76        __VMALLOC_RESERVE = memparse(arg, &arg) + VMALLOC_OFFSET;
  77        return 0;
  78}
  79early_param("vmalloc", parse_vmalloc);
  80
  81/*
  82 * reservetop=size reserves a hole at the top of the kernel address space which
  83 * a hypervisor can load into later.  Needed for dynamically loaded hypervisors,
  84 * so relocating the fixmap can be done before paging initialization.
  85 */
  86static int __init parse_reservetop(char *arg)
  87{
  88        unsigned long address;
  89
  90        if (!arg)
  91                return -EINVAL;
  92
  93        address = memparse(arg, &arg);
  94        reserve_top_address(address);
  95        early_ioremap_init();
  96        return 0;
  97}
  98early_param("reservetop", parse_reservetop);
  99