EmbeddedPkg/Library/PrePiMemoryAllocationLib/MemoryAllocationLib.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.<BR>
   5
   6   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 <PiPei.h>
  17
  18 #include <Library/BaseLib.h>
  19 #include <Library/PrePiLib.h>
  20 #include <Library/DebugLib.h>
  21
  22
  23
  24 /**
  25   Allocates one or more 4KB pages of type EfiBootServicesData.
  26
  27   Allocates the number of 4KB pages of MemoryType and returns a pointer to the
  28   allocated buffer.  The buffer returned is aligned on a 4KB boundary.  If Pages is 0, then NULL
  29   is returned.  If there is not enough memory remaining to satisfy the request, then NULL is
  30   returned.
  31
  32   @param  Pages                 The number of 4 KB pages to allocate.
  33
  34   @return A pointer to the allocated buffer or NULL if allocation fails.
  35
  36 **/
  37 VOID *
  38 EFIAPI
  39 AllocatePages (
  40   IN UINTN            Pages
  41   )
  42 {
  43   EFI_PEI_HOB_POINTERS                    Hob;
  44   EFI_PHYSICAL_ADDRESS                    Offset;
  45
  46   Hob.Raw = GetHobList ();
  47
  48   // Check to see if on 4k boundary
  49   Offset = Hob.HandoffInformationTable->EfiFreeMemoryTop & 0xFFF;
  50   if (Offset != 0) {
  51     // If not aligned, make the allocation aligned.
  52     Hob.HandoffInformationTable->EfiFreeMemoryTop -= Offset;
  53   }
  54
  55   //
  56   // Verify that there is sufficient memory to satisfy the allocation
  57   //
  58   if (Hob.HandoffInformationTable->EfiFreeMemoryTop - ((Pages * EFI_PAGE_SIZE) + sizeof (EFI_HOB_MEMORY_ALLOCATION)) < Hob.HandoffInformationTable->EfiFreeMemoryBottom) {
  59     return 0;
  60   } else {
  61     //
  62     // Update the PHIT to reflect the memory usage
  63     //
  64     Hob.HandoffInformationTable->EfiFreeMemoryTop -= Pages * EFI_PAGE_SIZE;
  65
  66     // This routine used to create a memory allocation HOB a la PEI, but that's not
  67     // necessary for us.
  68
  69     //
  70     // Create a memory allocation HOB.
  71     //
  72     BuildMemoryAllocationHob (
  73         Hob.HandoffInformationTable->EfiFreeMemoryTop,
  74         Pages * EFI_PAGE_SIZE,
  75         EfiBootServicesData
  76         );
  77     return (VOID *)(UINTN)Hob.HandoffInformationTable->EfiFreeMemoryTop;
  78   }
  79 }
  80
  81
  82 /**
  83   Allocates one or more 4KB pages of type EfiBootServicesData at a specified alignment.
  84
  85   Allocates the number of 4KB pages specified by Pages of type EfiBootServicesData with an
  86   alignment specified by Alignment.  The allocated buffer is returned.  If Pages is 0, then NULL is
  87   returned.  If there is not enough memory at the specified alignment remaining to satisfy the
  88   request, then NULL is returned.
  89   If Alignment is not a power of two and Alignment is not zero, then ASSERT().
  90
  91   @param  Pages                 The number of 4 KB pages to allocate.
  92   @param  Alignment             The requested alignment of the allocation.  Must be a power of two.
  93                                 If Alignment is zero, then byte alignment is used.
  94
  95   @return A pointer to the allocated buffer or NULL if allocation fails.
  96
  97 **/
  98 VOID *
  99 EFIAPI
 100 AllocateAlignedPages (
 101   IN UINTN  Pages,
 102   IN UINTN  Alignment
 103   )
 104 {
 105   VOID    *Memory;
 106   UINTN   AlignmentMask;
 107
 108   //
 109   // Alignment must be a power of two or zero.
 110   //
 111   ASSERT ((Alignment & (Alignment - 1)) == 0);
 112
 113   if (Pages == 0) {
 114     return NULL;
 115   }
 116   //
 117   // Make sure that Pages plus EFI_SIZE_TO_PAGES (Alignment) does not overflow.
 118   //
 119   ASSERT (Pages <= (MAX_ADDRESS - EFI_SIZE_TO_PAGES (Alignment)));
 120   //
 121   // We would rather waste some memory to save PEI code size.
 122   //
 123   Memory = (VOID *)(UINTN)AllocatePages (Pages + EFI_SIZE_TO_PAGES (Alignment));
 124   if (Alignment == 0) {
 125     AlignmentMask = Alignment;
 126   } else {
 127     AlignmentMask = Alignment - 1;
 128   }
 129   return (VOID *) (UINTN) (((UINTN) Memory + AlignmentMask) & ~AlignmentMask);
 130 }
 131
 132
 133
 134
 135 /**
 136   Allocates a buffer of type EfiBootServicesData.
 137
 138   Allocates the number bytes specified by AllocationSize of type EfiBootServicesData and returns a
 139   pointer to the allocated buffer.  If AllocationSize is 0, then a valid buffer of 0 size is
 140   returned.  If there is not enough memory remaining to satisfy the request, then NULL is returned.
 141
 142   @param  AllocationSize        The number of bytes to allocate.
 143
 144   @return A pointer to the allocated buffer or NULL if allocation fails.
 145
 146 **/
 147 VOID *
 148 EFIAPI
 149 AllocatePool (
 150   IN UINTN  AllocationSize
 151   )
 152 {
 153   EFI_HOB_MEMORY_POOL      *Hob;
 154
 155   Hob = GetHobList ();
 156
 157
 158   //
 159   // Verify that there is sufficient memory to satisfy the allocation
 160   //
 161   if (AllocationSize > 0x10000) {
 162     // Please call AllcoatePages for big allocations
 163     return 0;
 164   } else {
 165
 166     Hob = (EFI_HOB_MEMORY_POOL *)CreateHob (EFI_HOB_TYPE_MEMORY_POOL, (UINT16)(sizeof (EFI_HOB_TYPE_MEMORY_POOL) + AllocationSize));
 167     return (VOID *)(Hob + 1);
 168   }
 169 }
 170
 171 /**
 172   Frees a buffer that was previously allocated with one of the pool allocation functions in the
 173   Memory Allocation Library.
 174
 175   Frees the buffer specified by Buffer.  Buffer must have been allocated on a previous call to the
 176   pool allocation services of the Memory Allocation Library.  If it is not possible to free pool
 177   resources, then this function will perform no actions.
 178
 179   If Buffer was not allocated with a pool allocation function in the Memory Allocation Library,
 180   then ASSERT().
 181
 182   @param  Buffer                Pointer to the buffer to free.
 183
 184 **/
 185 VOID
 186 EFIAPI
 187 FreePool (
 188   IN VOID   *Buffer
 189   )
 190 {
 191   // Not implemented yet
 192 }