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/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
  23unsigned 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 */ 
  29void 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 */ 
  70void 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
  99unsigned long __FIXADDR_TOP = 0xfffff000;
 100EXPORT_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 */
 107static 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}
 116early_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 */
 123static 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}
 134early_param("reservetop", parse_reservetop);
 135