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
  12#include <asm/pgtable.h>
  13#include <asm/pgalloc.h>
  14#include <asm/fixmap.h>
  15#include <asm/e820/api.h>
  16#include <asm/tlb.h>
  17#include <asm/tlbflush.h>
  18#include <asm/io.h>
  19
  20unsigned int __VMALLOC_RESERVE = 128 << 20;
  21
  22/*
  23 * Associate a virtual page frame with a given physical page frame 
  24 * and protection flags for that frame.
  25 */ 
  26void set_pte_vaddr(unsigned long vaddr, pte_t pteval)
  27{
  28        pgd_t *pgd;
  29        p4d_t *p4d;
  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        p4d = p4d_offset(pgd, vaddr);
  40        if (p4d_none(*p4d)) {
  41                BUG();
  42                return;
  43        }
  44        pud = pud_offset(p4d, vaddr);
  45        if (pud_none(*pud)) {
  46                BUG();
  47                return;
  48        }
  49        pmd = pmd_offset(pud, vaddr);
  50        if (pmd_none(*pmd)) {
  51                BUG();
  52                return;
  53        }
  54        pte = pte_offset_kernel(pmd, vaddr);
  55        if (!pte_none(pteval))
  56                set_pte_at(&init_mm, vaddr, pte, pteval);
  57        else
  58                pte_clear(&init_mm, vaddr, pte);
  59
  60        /*
  61         * It's enough to flush this one mapping.
  62         * (PGE mappings get flushed as well)
  63         */
  64        __flush_tlb_one(vaddr);
  65}
  66
  67unsigned long __FIXADDR_TOP = 0xfffff000;
  68EXPORT_SYMBOL(__FIXADDR_TOP);
  69
  70/*
  71 * vmalloc=size forces the vmalloc area to be exactly 'size'
  72 * bytes. This can be used to increase (or decrease) the
  73 * vmalloc area - the default is 128m.
  74 */
  75static int __init parse_vmalloc(char *arg)
  76{
  77        if (!arg)
  78                return -EINVAL;
  79
  80        /* Add VMALLOC_OFFSET to the parsed value due to vm area guard hole*/
  81        __VMALLOC_RESERVE = memparse(arg, &arg) + VMALLOC_OFFSET;
  82        return 0;
  83}
  84early_param("vmalloc", parse_vmalloc);
  85
  86/*
  87 * reservetop=size reserves a hole at the top of the kernel address space which
  88 * a hypervisor can load into later.  Needed for dynamically loaded hypervisors,
  89 * so relocating the fixmap can be done before paging initialization.
  90 */
  91static int __init parse_reservetop(char *arg)
  92{
  93        unsigned long address;
  94
  95        if (!arg)
  96                return -EINVAL;
  97
  98        address = memparse(arg, &arg);
  99        reserve_top_address(address);
 100        early_ioremap_init();
 101        return 0;
 102}
 103early_param("reservetop", parse_reservetop);
 104