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a536e5d699
Replace traditional `#ifndef`/`#define`/`#endif` include guards with
`#pragma` once.
`#pragma once` is a widely supported preprocessor directive that
prevents header files from being included multiple times. It is
supported by all toolchains used to build edk2: GCC, Clang/LLVM, and
MSVC.
Note: Headers taken directly from external projects, such as those
in OvmfPkg/Include/IndustryStandard/Xen/ were not modified since they
may be periodically re-synced and do not follow other edk2 coding
stadards.
Compared to macro-based include guards, `#pragma once`:
- Eliminates the risk of macro name collisions or copy/paste errors
where two headers inadvertently use the same guard macro.
- Eliminate inconsistency in the way include guard macros are named
(e.g., some files use `__FILE_H__`, others use `FILE_H_`, etc.).
- Reduces boilerplate (three lines replaced by one).
- Avoids polluting the macro namespace with guard symbols.
- Can improve build times as the preprocessor can skip re-opening the
file entirely, rather than re-reading it to find the matching
`#endif` ("multiple-include optimization").
- Note that some compilers may already optimize traditional include
guards, by recognzining the idiomatic pattern.
This change is made acknowledging that overall portability of the
code will technically be reduced, as `#pragma once` is not part of the
C/C++ standards.
However, this is considered acceptable given:
1. edk2 already defines a subset of supported compilers in
BaseTools/Conf/tools_def.template, all of which have supported
`#pragma once` for over two decades.
2. There have been concerns raised to the project about inconsistent
include guard naming and potential macro collisions.
Approximate compiler support dates:
- MSVC: Supported since Visual C++ 4.2 (1996)
- GCC: Supported since 3.4 (2004)
(http://gnu.ist.utl.pt/software/gcc/gcc-3.4/changes.html)
- Clang (LLVM based): Since initial release in 2007
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
78 lines
2.7 KiB
C
78 lines
2.7 KiB
C
/** @file
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Define Memory Encrypted Virtualization base library helper function
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Copyright (c) 2020, Intel Corporation. All rights reserved.<BR>
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Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
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SPDX-License-Identifier: BSD-2-Clause-Patent
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**/
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#pragma once
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#include <Base.h>
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/**
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Returns boolean to indicate whether to indicate which, if any, memory encryption is enabled
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@param[in] Type Bitmask of encryption technologies to check is enabled
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@retval TRUE The encryption type(s) are enabled
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@retval FALSE The encryption type(s) are not enabled
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**/
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BOOLEAN
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EFIAPI
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MemEncryptTdxIsEnabled (
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VOID
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);
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/**
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This function clears memory encryption bit for the memory region specified by
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BaseAddress and NumPages from the current page table context.
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@param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
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current CR3)
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@param[in] BaseAddress The physical address that is the start
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address of a memory region.
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@param[in] NumPages The number of pages from start memory
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region.
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@retval RETURN_SUCCESS The attributes were cleared for the
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memory region.
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@retval RETURN_INVALID_PARAMETER Number of pages is zero.
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@retval RETURN_UNSUPPORTED Clearing the memory encryption attribute
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is not supported
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**/
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RETURN_STATUS
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EFIAPI
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MemEncryptTdxSetPageSharedBit (
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IN PHYSICAL_ADDRESS Cr3BaseAddress,
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IN PHYSICAL_ADDRESS BaseAddress,
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IN UINTN NumPages
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);
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/**
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This function sets memory encryption bit for the memory region specified by
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BaseAddress and NumPages from the current page table context.
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@param[in] Cr3BaseAddress Cr3 Base Address (if zero then use
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current CR3)
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@param[in] BaseAddress The physical address that is the start
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address of a memory region.
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@param[in] NumPages The number of pages from start memory
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region.
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@retval RETURN_SUCCESS The attributes were set for the memory
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region.
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@retval RETURN_INVALID_PARAMETER Number of pages is zero.
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@retval RETURN_UNSUPPORTED Setting the memory encryption attribute
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is not supported
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**/
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RETURN_STATUS
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EFIAPI
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MemEncryptTdxClearPageSharedBit (
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IN PHYSICAL_ADDRESS Cr3BaseAddress,
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IN PHYSICAL_ADDRESS BaseAddress,
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IN UINTN NumPages
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);
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