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   Frees one or more 4KB pages that were previously allocated with one of the page allocation
 135   functions in the Memory Allocation Library.
 136
 137   Frees the number of 4KB pages specified by Pages from the buffer specified by Buffer.  Buffer
 138   must have been allocated on a previous call to the page allocation services of the Memory
 139   Allocation Library.  If it is not possible to free allocated pages, then this function will
 140   perform no actions.
 141
 142   If Buffer was not allocated with a page allocation function in the Memory Allocation Library,
 143   then ASSERT().
 144   If Pages is zero, then ASSERT().
 145
 146   @param  Buffer                Pointer to the buffer of pages to free.
 147   @param  Pages                 The number of 4 KB pages to free.
 148
 149 **/
 150 VOID
 151 EFIAPI
 152 FreePages (
 153   IN VOID   *Buffer,
 154   IN UINTN  Pages
 155   )
 156 {
 157   // For now, we do not support the ability to free pages in the PrePei Memory Allocator.
 158   // The allocated memory is lost.
 159 }
 160
 161 /**
 162   Allocates a buffer of type EfiBootServicesData.
 163
 164   Allocates the number bytes specified by AllocationSize of type EfiBootServicesData and returns a
 165   pointer to the allocated buffer.  If AllocationSize is 0, then a valid buffer of 0 size is
 166   returned.  If there is not enough memory remaining to satisfy the request, then NULL is returned.
 167
 168   @param  AllocationSize        The number of bytes to allocate.
 169
 170   @return A pointer to the allocated buffer or NULL if allocation fails.
 171
 172 **/
 173 VOID *
 174 EFIAPI
 175 AllocatePool (
 176   IN UINTN  AllocationSize
 177   )
 178 {
 179   EFI_HOB_MEMORY_POOL      *Hob;
 180
 181   Hob = GetHobList ();
 182
 183
 184   //
 185   // Verify that there is sufficient memory to satisfy the allocation
 186   //
 187   if (AllocationSize > 0x10000) {
 188     // Please call AllcoatePages for big allocations
 189     return 0;
 190   } else {
 191
 192     Hob = (EFI_HOB_MEMORY_POOL *)CreateHob (EFI_HOB_TYPE_MEMORY_POOL, (UINT16)(sizeof (EFI_HOB_TYPE_MEMORY_POOL) + AllocationSize));
 193     return (VOID *)(Hob + 1);
 194   }
 195 }
 196
 197 /**
 198   Frees a buffer that was previously allocated with one of the pool allocation functions in the
 199   Memory Allocation Library.
 200
 201   Frees the buffer specified by Buffer.  Buffer must have been allocated on a previous call to the
 202   pool allocation services of the Memory Allocation Library.  If it is not possible to free pool
 203   resources, then this function will perform no actions.
 204
 205   If Buffer was not allocated with a pool allocation function in the Memory Allocation Library,
 206   then ASSERT().
 207
 208   @param  Buffer                Pointer to the buffer to free.
 209
 210 **/
 211 VOID
 212 EFIAPI
 213 FreePool (
 214   IN VOID   *Buffer
 215   )
 216 {
 217   // Not implemented yet
 218 }