EmbeddedPkg/PrePiMemoryAllocationLib: Add reserved memory allocations

PrePiMemoryAllocationLib does not implement functions to allocate
EfiMemoryReservedType. These are implemented in other instances of
MemoryAllocationLib (Dxe, Uefi, PiSmmCore, SmmMemory).

Add AllocateReservedPages() and AllocateAlignedReservedPages()
functions to make it consistent with other MemoryAllocationLib
intstances.

Signed-off-by: Vishal Oliyil Kunnil <vishalo@qti.qualcomm.com>

EmbeddedPkg/Library/PrePiMemoryAllocationLib/MemoryAllocationLib.c

@@ -98,6 +98,28 @@ AllocateRuntimePages (
   return InternalAllocatePages (Pages, EfiRuntimeServicesData);
 }
 
+/**
+  Allocates one or more 4KB pages of type EfiReservedMemoryType.
+
+  Allocates the number of 4KB pages of type EfiReservedMemoryTypes and returns a pointer to the
+  allocated buffer.  The buffer returned is aligned on a 4KB boundary.  If Pages is 0, then NULL
+  is returned.  If there is not enough memory remaining to satisfy the request, then NULL is
+  returned.
+
+  @param  Pages                 The number of 4 KB pages to allocate.
+
+  @return A pointer to the allocated buffer or NULL if allocation fails.
+
+**/
+VOID *
+EFIAPI
+AllocateReservedPages (
+  IN UINTN  Pages
+  )
+{
+  return InternalAllocatePages (Pages, EfiReservedMemoryType);
+}
+
 /**
   Allocates one or more 4KB pages of type EfiBootServicesData at a specified alignment.
 
@@ -150,6 +172,58 @@ AllocateAlignedPages (
   return (VOID *)(UINTN)(((UINTN)Memory + AlignmentMask) & ~AlignmentMask);
 }
 
+/**
+  Allocates one or more 4KB pages of type EfiReservedMemoryType at a specified alignment.
+
+  Allocates the number of 4KB pages specified by Pages of type EfiReservedMemoryType with an
+  alignment specified by Alignment.  The allocated buffer is returned.  If Pages is 0, then NULL is
+  returned.  If there is not enough memory at the specified alignment remaining to satisfy the
+  request, then NULL is returned.
+  If Alignment is not a power of two and Alignment is not zero, then ASSERT().
+
+  @param  Pages                 The number of 4 KB pages to allocate.
+  @param  Alignment             The requested alignment of the allocation.  Must be a power of two.
+                                If Alignment is zero, then byte alignment is used.
+
+  @return A pointer to the allocated buffer or NULL if allocation fails.
+
+**/
+VOID *
+EFIAPI
+AllocateAlignedReservedPages (
+  IN UINTN  Pages,
+  IN UINTN  Alignment
+  )
+{
+  VOID   *Memory;
+  UINTN  AlignmentMask;
+
+  //
+  // Alignment must be a power of two or zero.
+  //
+  ASSERT ((Alignment & (Alignment - 1)) == 0);
+
+  if (Pages == 0) {
+    return NULL;
+  }
+
+  //
+  // Make sure that Pages plus EFI_SIZE_TO_PAGES (Alignment) does not overflow.
+  //
+  ASSERT (Pages <= (MAX_ADDRESS - EFI_SIZE_TO_PAGES (Alignment)));
+  //
+  // We would rather waste some memory to save PEI code size.
+  //
+  Memory = (VOID *)(UINTN)AllocateReservedPages (Pages + EFI_SIZE_TO_PAGES (Alignment));
+  if (Alignment == 0) {
+    AlignmentMask = Alignment;
+  } else {
+    AlignmentMask = Alignment - 1;
+  }
+
+  return (VOID *)(UINTN)(((UINTN)Memory + AlignmentMask) & ~AlignmentMask);
+}
+
 /**
   Frees one or more 4KB pages that were previously allocated with one of the page allocation
   functions in the Memory Allocation Library.