EmbeddedPkg/Library/PrePiLib/Memory.c

   1 /** @file
   2   Implementation of the 6 PEI Ffs (FV) APIs in library form.
   3
   4   Copyright (c) 2008-2009, Apple Inc. All rights reserved.
   5
   6   All rights reserved. This program and the accompanying materials
   7   are licensed and made available under the terms and conditions of the BSD License
   8   which accompanies this distribution.  The full text of the license may be found at
   9   http://opensource.org/licenses/bsd-license.php
  10
  11   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13
  14 **/
  15
  16 #include <PrePi.h>
  17
  18
  19
  20 /**
  21   Allocates one or more 4KB pages of type EfiBootServicesData.
  22
  23   Allocates the number of 4KB pages of MemoryType and returns a pointer to the
  24   allocated buffer.  The buffer returned is aligned on a 4KB boundary.  If Pages is 0, then NULL
  25   is returned.  If there is not enough memory remaining to satisfy the request, then NULL is
  26   returned.
  27
  28   @param  Pages                 The number of 4 KB pages to allocate.
  29
  30   @return A pointer to the allocated buffer or NULL if allocation fails.
  31
  32 **/
  33 VOID *
  34 EFIAPI
  35 AllocatePages (
  36   IN UINTN            Pages
  37   )
  38 {
  39   EFI_PEI_HOB_POINTERS                    Hob;
  40   EFI_PHYSICAL_ADDRESS                    Offset;
  41
  42   Hob.Raw = GetHobList ();
  43
  44   // Check to see if on 4k boundary
  45   Offset = Hob.HandoffInformationTable->EfiFreeMemoryTop & 0xFFF;
  46   if (Offset != 0) {
  47     // If not aligned, make the allocation aligned.
  48     Hob.HandoffInformationTable->EfiFreeMemoryTop -= Offset;
  49   }
  50
  51   //
  52   // Verify that there is sufficient memory to satisfy the allocation
  53   //
  54   if (Hob.HandoffInformationTable->EfiFreeMemoryTop - ((Pages * EFI_PAGE_SIZE) + sizeof (EFI_HOB_MEMORY_ALLOCATION)) < Hob.HandoffInformationTable->EfiFreeMemoryBottom) {
  55     return 0;
  56   } else {
  57     //
  58     // Update the PHIT to reflect the memory usage
  59     //
  60     Hob.HandoffInformationTable->EfiFreeMemoryTop -= Pages * EFI_PAGE_SIZE;
  61
  62     // This routine used to create a memory allocation HOB a la PEI, but that's not
  63     // necessary for us.
  64
  65     return (VOID *)(UINTN)Hob.HandoffInformationTable->EfiFreeMemoryTop;
  66   }
  67 }
  68
  69
  70 /**
  71   Allocates one or more 4KB pages of type EfiBootServicesData at a specified alignment.
  72
  73   Allocates the number of 4KB pages specified by Pages of type EfiBootServicesData with an
  74   alignment specified by Alignment.  The allocated buffer is returned.  If Pages is 0, then NULL is
  75   returned.  If there is not enough memory at the specified alignment remaining to satisfy the
  76   request, then NULL is returned.
  77   If Alignment is not a power of two and Alignment is not zero, then ASSERT().
  78
  79   @param  Pages                 The number of 4 KB pages to allocate.
  80   @param  Alignment             The requested alignment of the allocation.  Must be a power of two.
  81                                 If Alignment is zero, then byte alignment is used.
  82
  83   @return A pointer to the allocated buffer or NULL if allocation fails.
  84
  85 **/
  86 VOID *
  87 EFIAPI
  88 AllocateAlignedPages (
  89   IN UINTN  Pages,
  90   IN UINTN  Alignment
  91   )
  92 {
  93   VOID    *Memory;
  94   UINTN   AlignmentMask;
  95
  96   //
  97   // Alignment must be a power of two or zero.
  98   //
  99   ASSERT ((Alignment & (Alignment - 1)) == 0);
 100
 101   if (Pages == 0) {
 102     return NULL;
 103   }
 104   //
 105   // Make sure that Pages plus EFI_SIZE_TO_PAGES (Alignment) does not overflow.
 106   //
 107   ASSERT (Pages <= (MAX_ADDRESS - EFI_SIZE_TO_PAGES (Alignment)));
 108   //
 109   // We would rather waste some memory to save PEI code size.
 110   //
 111   Memory = (VOID *)(UINTN)AllocatePages (Pages + EFI_SIZE_TO_PAGES (Alignment));
 112   if (Alignment == 0) {
 113     AlignmentMask = Alignment;
 114   } else {
 115     AlignmentMask = Alignment - 1;
 116   }
 117   return (VOID *) (UINTN) (((UINTN) Memory + AlignmentMask) & ~AlignmentMask);
 118 }
 119
 120
 121
 122
 123 /**
 124   Allocates a buffer of type EfiBootServicesData.
 125
 126   Allocates the number bytes specified by AllocationSize of type EfiBootServicesData and returns a
 127   pointer to the allocated buffer.  If AllocationSize is 0, then a valid buffer of 0 size is
 128   returned.  If there is not enough memory remaining to satisfy the request, then NULL is returned.
 129
 130   @param  AllocationSize        The number of bytes to allocate.
 131
 132   @return A pointer to the allocated buffer or NULL if allocation fails.
 133
 134 **/
 135 VOID *
 136 EFIAPI
 137 AllocatePool (
 138   IN UINTN  AllocationSize
 139   )
 140 {
 141   EFI_HOB_MEMORY_POOL      *Hob;
 142
 143   Hob = GetHobList ();
 144
 145
 146   //
 147   // Verify that there is sufficient memory to satisfy the allocation
 148   //
 149   if (AllocationSize > 0x10000) {
 150     // Please call AllcoatePages for big allocations
 151     return 0;
 152   } else {
 153
 154     Hob = (EFI_HOB_MEMORY_POOL *)CreateHob (EFI_HOB_TYPE_MEMORY_POOL, (UINT16)(sizeof (EFI_HOB_TYPE_MEMORY_POOL) + AllocationSize));
 155     return (VOID *)(Hob + 1);
 156   }
 157 }
 158
 159
 160