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ArmPkg/ArmSmcLib: Fixed SMC helper functions

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The SMC helper functions were buggy as they were assuming that
the values in x1-x7 registers were preserved across an SMC call,
which is not the case.  This patch fixes this issue.

It also simplifies the code by providing only 1 version of the SMC
helper function.  We used to have 4 versions depending on the number
of arguments.  The problem with this approach was that the number of
arguments also dictated the number of return values, which is
completely unrelated.  E.g. you can have an SMC call that takes
1 argument but returns 4 values.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15748 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
Olivier Martin
2014-08-04 14:18:13 +00:00
committed by oliviermartin
parent 9a9dd4e839
commit b4e53e389d
7 changed files with 102 additions and 221 deletions
Download Patch File Download Diff File Expand all files Collapse all files

48
ArmPkg/Include/Library/ArmSmcLib.h
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@ -1,6 +1,6 @@
/** @file
*
* Copyright (c) 2012, ARM Limited. All rights reserved.
* Copyright (c) 2012-2014, ARM Limited. All rights reserved.
*
* This program and the accompanying materials
* are licensed and made available under the terms and conditions of the BSD License
@ -15,30 +15,32 @@
#ifndef __ARM_SMC_LIB__
#define __ARM_SMC_LIB__
/**
* The size of the SMC arguments are different between AArch64 and AArch32.
* The native size is used for the arguments.
*/
typedef struct {
UINTN Arg0;
UINTN Arg1;
UINTN Arg2;
UINTN Arg3;
UINTN Arg4;
UINTN Arg5;
UINTN Arg6;
UINTN Arg7;
} ARM_SMC_ARGS;
/**
Trigger an SMC call
SMC calls can take up to 7 arguments and return up to 4 return values.
Therefore, the 4 first fields in the ARM_SMC_ARGS structure are used
for both input and output values.
**/
VOID
ArmCallSmc (
IN OUT UINTN *Rx
);
VOID
ArmCallSmcArg1 (
IN OUT UINTN *Rx,
IN OUT UINTN *Arg1
);
VOID
ArmCallSmcArg2 (
IN OUT UINTN *Rx,
IN OUT UINTN *Arg1,
IN OUT UINTN *Arg2
);
VOID
ArmCallSmcArg3 (
IN OUT UINTN *Rx,
IN OUT UINTN *Arg1,
IN OUT UINTN *Arg2,
IN OUT UINTN *Arg3
IN OUT ARM_SMC_ARGS *Args
);
#endif