OvmfPkg/CpuHotplugSmm: introduce Post-SMM Pen for hot-added CPUs

[mirror_edk2.git] / OvmfPkg / CpuHotplugSmm / Smbase.c

/** @file\r
  SMBASE relocation for hot-plugged CPUs.\r
\r
  Copyright (c) 2020, Red Hat, Inc.\r
\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
**/\r
\r
#include <Base.h>                             // BASE_1MB\r
#include <Library/BaseMemoryLib.h>            // CopyMem()\r
#include <Library/DebugLib.h>                 // DEBUG()\r
\r
#include "Smbase.h"\r
\r
extern CONST UINT8 mPostSmmPen[];\r
extern CONST UINT16 mPostSmmPenSize;\r
\r
/**\r
  Allocate a non-SMRAM reserved memory page for the Post-SMM Pen for hot-added\r
  CPUs.\r
\r
  This function may only be called from the entry point function of the driver.\r
\r
  @param[out] PenAddress   The address of the allocated (normal RAM) reserved\r
                           page.\r
\r
  @param[in] BootServices  Pointer to the UEFI boot services table. Used for\r
                           allocating the normal RAM (not SMRAM) reserved page.\r
\r
  @retval EFI_SUCCESS          Allocation successful.\r
\r
  @retval EFI_BAD_BUFFER_SIZE  The Post-SMM Pen template is not smaller than\r
                               EFI_PAGE_SIZE.\r
\r
  @return                      Error codes propagated from underlying services.\r
                               DEBUG_ERROR messages have been logged. No\r
                               resources have been allocated.\r
**/\r
EFI_STATUS\r
SmbaseAllocatePostSmmPen (\r
  OUT UINT32                  *PenAddress,\r
  IN  CONST EFI_BOOT_SERVICES *BootServices\r
  )\r
{\r
  EFI_STATUS           Status;\r
  EFI_PHYSICAL_ADDRESS Address;\r
\r
  //\r
  // The pen code must fit in one page, and the last byte must remain free for\r
  // signaling the SMM Monarch.\r
  //\r
  if (mPostSmmPenSize >= EFI_PAGE_SIZE) {\r
    Status = EFI_BAD_BUFFER_SIZE;\r
    DEBUG ((DEBUG_ERROR, "%a: mPostSmmPenSize=%u: %r\n", __FUNCTION__,\r
      mPostSmmPenSize, Status));\r
    return Status;\r
  }\r
\r
  Address = BASE_1MB - 1;\r
  Status = BootServices->AllocatePages (AllocateMaxAddress,\r
                           EfiReservedMemoryType, 1, &Address);\r
  if (EFI_ERROR (Status)) {\r
    DEBUG ((DEBUG_ERROR, "%a: AllocatePages(): %r\n", __FUNCTION__, Status));\r
    return Status;\r
  }\r
\r
  DEBUG ((DEBUG_INFO, "%a: Post-SMM Pen at 0x%Lx\n", __FUNCTION__, Address));\r
  *PenAddress = (UINT32)Address;\r
  return EFI_SUCCESS;\r
}\r
\r
/**\r
  Copy the Post-SMM Pen template code into the reserved page allocated with\r
  SmbaseAllocatePostSmmPen().\r
\r
  Note that this effects an "SMRAM to normal RAM" copy.\r
\r
  The SMM Monarch is supposed to call this function from the root MMI handler.\r
\r
  @param[in] PenAddress  The allocation address returned by\r
                         SmbaseAllocatePostSmmPen().\r
**/\r
VOID\r
SmbaseReinstallPostSmmPen (\r
  IN UINT32 PenAddress\r
  )\r
{\r
  CopyMem ((VOID *)(UINTN)PenAddress, mPostSmmPen, mPostSmmPenSize);\r
}\r
\r
/**\r
  Release the reserved page allocated with SmbaseAllocatePostSmmPen().\r
\r
  This function may only be called from the entry point function of the driver,\r
  on the error path.\r
\r
  @param[in] PenAddress    The allocation address returned by\r
                           SmbaseAllocatePostSmmPen().\r
\r
  @param[in] BootServices  Pointer to the UEFI boot services table. Used for\r
                           releasing the normal RAM (not SMRAM) reserved page.\r
**/\r
VOID\r
SmbaseReleasePostSmmPen (\r
  IN UINT32                  PenAddress,\r
  IN CONST EFI_BOOT_SERVICES *BootServices\r
  )\r
{\r
  BootServices->FreePages (PenAddress, 1);\r
}\r