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 INIT_FUNCTION
  20 Ki386EnableGlobalPage(IN volatile ULONG_PTR Context)
  21 {
  22     volatile PLONG Count = (PLONG)Context;
  23     ULONG Cr4, Cr3;
  24
  25     /* Disable interrupts */
  26     _disable();
  27
  28     /* Decrease CPU Count and loop until it's reached 0 */
  29     do {InterlockedDecrement(Count);} while (!*Count);
  30
  31     /* Now check if this is the Boot CPU */
  32     if (!KeGetPcr()->Number)
  33     {
  34         /* It is.FIXME: Patch KeFlushCurrentTb */
  35     }
  36
  37     /* Now get CR4 and make sure PGE is masked out */
  38     Cr4 = __readcr4();
  39     __writecr4(Cr4 & ~CR4_PGE);
  40
  41     /* Flush the TLB */
  42     Cr3 = __readcr3();
  43     __writecr3(Cr3);
  44
  45     /* Now enable PGE */
  46     DPRINT("Global page support detected but not yet taken advantage of\n");
  47     //__writecr4(Cr4 | CR4_PGE);
  48
  49     /* Restore interrupts */
  50     _enable();
  51     return 0;
  52 }
  53
  54 VOID
  55 NTAPI
  56 INIT_FUNCTION
  57 KiInitializePAT(VOID)
  58 {
  59     /* FIXME: Support this */
  60     DPRINT("PAT support detected but not yet taken advantage of\n");
  61 }