ntoskrnl/ke/i386/patpge.c

   1 /*
   2 * PROJECT:         ReactOS Kernel
   3 * LICENSE:         GPL - See COPYING in the top level directory
   4 * FILE:            ntoskrnl/ke/i386/patpge.c
   5 * PURPOSE:         Support for PAT and PGE (Large Pages)
   6 * PROGRAMMERS:     Alex Ionescu (alex.ionescu@reactos.org)
   7 */
   8
   9 /* INCLUDES ******************************************************************/
  10
  11 #include <ntoskrnl.h>
  12 #define NDEBUG
  13 #include <debug.h>
  14
  15 /* FUNCTIONS *****************************************************************/
  16
  17 ULONG_PTR
  18 NTAPI
  19 Ki386EnableGlobalPage(IN volatile ULONG_PTR Context)
  20 {
  21     volatile PLONG Count = (PLONG)Context;
  22     ULONG Cr4, Cr3;
  23
  24     /* Disable interrupts */
  25     _disable();
  26
  27     /* Decrease CPU Count and loop until it's reached 0 */
  28     do {InterlockedDecrement(Count);} while (!*Count);
  29
  30     /* Now check if this is the Boot CPU */
  31     if (!KeGetPcr()->Number)
  32     {
  33         /* It is.FIXME: Patch KeFlushCurrentTb */
  34     }
  35
  36     /* Now get CR4 and make sure PGE is masked out */
  37     Cr4 = __readcr4();
  38     __writecr4(Cr4 & ~CR4_PGE);
  39
  40     /* Flush the TLB */
  41     Cr3 = __readcr3();
  42     __writecr3(Cr3);
  43
  44     /* Now enable PGE */
  45     DPRINT1("Global page support detected but not yet taken advantage of\n");
  46     //__writecr4(Cr4 | CR4_PGE);
  47
  48     /* Restore interrupts */
  49     _enable();
  50     return 0;
  51 }
  52
  53 VOID
  54 NTAPI
  55 KiInitializePAT(VOID)
  56 {
  57     /* FIXME: Support this */
  58     DPRINT1("PAT support detected but not yet taken advantage of\n");
  59 }