audk/MdeModulePkg/Core/PiSmmCore/Page.c

/** @file
  SMM Memory page management functions.

  Copyright (c) 2009 - 2010, Intel Corporation. All rights reserved.<BR>
  This program and the accompanying materials are licensed and made available 
  under the terms and conditions of the BSD License which accompanies this 
  distribution.  The full text of the license may be found at        
  http://opensource.org/licenses/bsd-license.php                                            

  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,                     
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.             

**/

#include "PiSmmCore.h"

#define TRUNCATE_TO_PAGES(a)  ((a) >> EFI_PAGE_SHIFT)

typedef struct {
  LIST_ENTRY  Link;
  UINTN       NumberOfPages;
} FREE_PAGE_LIST;

LIST_ENTRY  mSmmMemoryMap = INITIALIZE_LIST_HEAD_VARIABLE (mSmmMemoryMap);

/**
  Internal Function. Allocate n pages from given free page node.

  @param  Pages                  The free page node.
  @param  NumberOfPages          Number of pages to be allocated.
  @param  MaxAddress             Request to allocate memory below this address.

  @return Memory address of allocated pages.

**/
UINTN
InternalAllocPagesOnOneNode (
  IN OUT FREE_PAGE_LIST  *Pages,
  IN     UINTN           NumberOfPages,
  IN     UINTN           MaxAddress
  )
{
  UINTN           Top;
  UINTN           Bottom;
  FREE_PAGE_LIST  *Node;

  Top = TRUNCATE_TO_PAGES (MaxAddress + 1 - (UINTN)Pages);
  if (Top > Pages->NumberOfPages) {
    Top = Pages->NumberOfPages;
  }
  Bottom = Top - NumberOfPages;

  if (Top < Pages->NumberOfPages) {
    Node = (FREE_PAGE_LIST*)((UINTN)Pages + EFI_PAGES_TO_SIZE (Top));
    Node->NumberOfPages = Pages->NumberOfPages - Top;
    InsertHeadList (&Pages->Link, &Node->Link);
  }

  if (Bottom > 0) {
    Pages->NumberOfPages = Bottom;
  } else {
    RemoveEntryList (&Pages->Link);
  }

  return (UINTN)Pages + EFI_PAGES_TO_SIZE (Bottom);
}

/**
  Internal Function. Allocate n pages from free page list below MaxAddress.

  @param  FreePageList           The free page node.
  @param  NumberOfPages          Number of pages to be allocated.
  @param  MaxAddress             Request to allocate memory below this address.

  @return Memory address of allocated pages.

**/
UINTN
InternalAllocMaxAddress (
  IN OUT LIST_ENTRY  *FreePageList,
  IN     UINTN       NumberOfPages,
  IN     UINTN       MaxAddress
  )
{
  LIST_ENTRY      *Node;
  FREE_PAGE_LIST  *Pages;

  for (Node = FreePageList->BackLink; Node != FreePageList; Node = Node->BackLink) {
    Pages = BASE_CR (Node, FREE_PAGE_LIST, Link);
    if (Pages->NumberOfPages >= NumberOfPages &&
        (UINTN)Pages + EFI_PAGES_TO_SIZE (NumberOfPages) - 1 <= MaxAddress) {
      return InternalAllocPagesOnOneNode (Pages, NumberOfPages, MaxAddress);
    }
  }
  return (UINTN)(-1);
}

/**
  Internal Function. Allocate n pages from free page list at given address.

  @param  FreePageList           The free page node.
  @param  NumberOfPages          Number of pages to be allocated.
  @param  MaxAddress             Request to allocate memory below this address.

  @return Memory address of allocated pages.

**/
UINTN
InternalAllocAddress (
  IN OUT LIST_ENTRY  *FreePageList,
  IN     UINTN       NumberOfPages,
  IN     UINTN       Address
  )
{
  UINTN           EndAddress;
  LIST_ENTRY      *Node;
  FREE_PAGE_LIST  *Pages;

  if ((Address & EFI_PAGE_MASK) != 0) {
    return ~Address;
  }

  EndAddress = Address + EFI_PAGES_TO_SIZE (NumberOfPages);
  for (Node = FreePageList->BackLink; Node!= FreePageList; Node = Node->BackLink) {
    Pages = BASE_CR (Node, FREE_PAGE_LIST, Link);
    if ((UINTN)Pages <= Address) {
      if ((UINTN)Pages + EFI_PAGES_TO_SIZE (Pages->NumberOfPages) < EndAddress) {
        break;
      }
      return InternalAllocPagesOnOneNode (Pages, NumberOfPages, EndAddress);
    }
  }
  return ~Address;
}

/**
  Allocates pages from the memory map.

  @param  Type                   The type of allocation to perform.
  @param  MemoryType             The type of memory to turn the allocated pages
                                 into.
  @param  NumberOfPages          The number of pages to allocate.
  @param  Memory                 A pointer to receive the base allocated memory
                                 address.

  @retval EFI_INVALID_PARAMETER  Parameters violate checking rules defined in spec.
  @retval EFI_NOT_FOUND          Could not allocate pages match the requirement.
  @retval EFI_OUT_OF_RESOURCES   No enough pages to allocate.
  @retval EFI_SUCCESS            Pages successfully allocated.

**/
EFI_STATUS
EFIAPI
SmmAllocatePages (
  IN  EFI_ALLOCATE_TYPE     Type,
  IN  EFI_MEMORY_TYPE       MemoryType,
  IN  UINTN                 NumberOfPages,
  OUT EFI_PHYSICAL_ADDRESS  *Memory
  )
{
  UINTN  RequestedAddress;

  if (MemoryType != EfiRuntimeServicesCode &&
      MemoryType != EfiRuntimeServicesData) {
    return EFI_INVALID_PARAMETER;
  }

  if (NumberOfPages > TRUNCATE_TO_PAGES ((UINTN)-1) + 1) {
    return EFI_OUT_OF_RESOURCES;
  }

  //
  // We don't track memory type in SMM
  //
  RequestedAddress = (UINTN)*Memory;
  switch (Type) {
    case AllocateAnyPages:
      RequestedAddress = (UINTN)(-1);
    case AllocateMaxAddress:
      *Memory = InternalAllocMaxAddress (
                  &mSmmMemoryMap,
                  NumberOfPages,
                  RequestedAddress
                  );
      if (*Memory == (UINTN)-1) {
        return EFI_OUT_OF_RESOURCES;
      } 
      break;
    case AllocateAddress:
      *Memory = InternalAllocAddress (
                  &mSmmMemoryMap,
                  NumberOfPages,
                  RequestedAddress
                  );
      if (*Memory != RequestedAddress) {
        return EFI_NOT_FOUND;
      }
      break;
    default:
      return EFI_INVALID_PARAMETER;
  }
  return EFI_SUCCESS;
}

/**
  Internal Function. Merge two adjacent nodes.

  @param  First             The first of two nodes to merge.

  @return Pointer to node after merge (if success) or pointer to next node (if fail).

**/
FREE_PAGE_LIST *
InternalMergeNodes (
  IN FREE_PAGE_LIST  *First
  )
{
  FREE_PAGE_LIST  *Next;

  Next = BASE_CR (First->Link.ForwardLink, FREE_PAGE_LIST, Link);
  ASSERT (
    TRUNCATE_TO_PAGES ((UINTN)Next - (UINTN)First) >= First->NumberOfPages);

  if (TRUNCATE_TO_PAGES ((UINTN)Next - (UINTN)First) == First->NumberOfPages) {
    First->NumberOfPages += Next->NumberOfPages;
    RemoveEntryList (&Next->Link);
    Next = First;
  }
  return Next;
}

/**
  Frees previous allocated pages.

  @param  Memory                 Base address of memory being freed.
  @param  NumberOfPages          The number of pages to free.

  @retval EFI_NOT_FOUND          Could not find the entry that covers the range.
  @retval EFI_INVALID_PARAMETER  Address not aligned.
  @return EFI_SUCCESS            Pages successfully freed.

**/
EFI_STATUS
EFIAPI
SmmFreePages (
  IN EFI_PHYSICAL_ADDRESS  Memory,
  IN UINTN                 NumberOfPages
  )
{
  LIST_ENTRY      *Node;
  FREE_PAGE_LIST  *Pages;

  if ((Memory & EFI_PAGE_MASK) != 0) {
    return EFI_INVALID_PARAMETER;
  }

  Pages = NULL;
  Node = mSmmMemoryMap.ForwardLink;
  while (Node != &mSmmMemoryMap) {
    Pages = BASE_CR (Node, FREE_PAGE_LIST, Link);
    if (Memory < (UINTN)Pages) {
      break;
    }
    Node = Node->ForwardLink;
  }

  if (Node != &mSmmMemoryMap &&
      Memory + EFI_PAGES_TO_SIZE (NumberOfPages) > (UINTN)Pages) {
    return EFI_INVALID_PARAMETER;
  }

  if (Node->BackLink != &mSmmMemoryMap) {
    Pages = BASE_CR (Node->BackLink, FREE_PAGE_LIST, Link);
    if ((UINTN)Pages + EFI_PAGES_TO_SIZE (Pages->NumberOfPages) > Memory) {
      return EFI_INVALID_PARAMETER;
    }
  }

  Pages = (FREE_PAGE_LIST*)(UINTN)Memory;
  Pages->NumberOfPages = NumberOfPages;
  InsertTailList (Node, &Pages->Link);

  if (Pages->Link.BackLink != &mSmmMemoryMap) {
    Pages = InternalMergeNodes (
              BASE_CR (Pages->Link.BackLink, FREE_PAGE_LIST, Link)
              );
  }

  if (Node != &mSmmMemoryMap) {
    InternalMergeNodes (Pages);
  }

  return EFI_SUCCESS;
}

/**
  Add free SMRAM region for use by memory service.

  @param  MemBase                Base address of memory region.
  @param  MemLength              Length of the memory region.
  @param  Type                   Memory type.
  @param  Attributes             Memory region state.

**/
VOID
SmmAddMemoryRegion (
  IN  EFI_PHYSICAL_ADDRESS  MemBase,
  IN  UINT64                MemLength,
  IN  EFI_MEMORY_TYPE       Type,
  IN  UINT64                Attributes
  )
{
  UINTN  AlignedMemBase;

  //
  // Do not add memory regions that is already allocated, needs testing, or needs ECC initialization
  //
  if ((Attributes & (EFI_ALLOCATED | EFI_NEEDS_TESTING | EFI_NEEDS_ECC_INITIALIZATION)) != 0) {
    return;
  }
  
  //
  // Align range on an EFI_PAGE_SIZE boundary
  //  
  AlignedMemBase = (UINTN)(MemBase + EFI_PAGE_MASK) & ~EFI_PAGE_MASK;
  MemLength -= AlignedMemBase - MemBase;
  SmmFreePages (AlignedMemBase, TRUNCATE_TO_PAGES ((UINTN)MemLength));
}