;; @file
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; This file provides assembly 64-bit atomic reads/writes required for memory initialization.
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;
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; Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
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; SPDX-License-Identifier: BSD-2-Clause-Patent
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;
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;;
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SECTION .TEXT
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;-----------------------------------------------------------------------------
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;
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; Section: SaMmioRead64
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;
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; Description: Read 64 bits from the Memory Mapped I/O space.
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; Use MMX instruction for atomic access, because some MC registers have side effect.
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;
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; @param[in] Address - Memory mapped I/O address.
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;
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;-----------------------------------------------------------------------------
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;UINT64
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;SaMmioRead64 (
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; IN UINTN Address
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; )
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global ASM_PFX(SaMmioRead64)
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ASM_PFX(SaMmioRead64):
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sub esp, 16
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movq [esp], mm0 ;Save mm0 on stack
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mov edx, [esp + 20] ;edx = Address
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movq mm0, [edx] ;mm0 = [Address]
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movq [esp + 8], mm0 ;Store mm0 on Stack
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movq mm0, [esp] ;Restore mm0
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emms
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mov eax, [esp + 8] ;eax = [Address][31:0]
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mov edx, [esp + 12] ;edx = [Address][64:32]
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add esp, 16
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ret
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;-----------------------------------------------------------------------------
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;
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; Section: SaMmioWrite64
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;
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; Description: Write 64 bits to the Memory Mapped I/O space.
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; Use MMX instruction for atomic access, because some MC registers have side effect.
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;
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; @param[in] Address - Memory mapped I/O address.
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; @param[in] Value - The value to write.
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;
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;-----------------------------------------------------------------------------
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;UINT64
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;SaMmioWrite64 (
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; IN UINTN Address,
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; IN UINT64 Value
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; )
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global ASM_PFX(SaMmioWrite64)
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ASM_PFX(SaMmioWrite64):
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sub esp, 8
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movq [esp], mm0 ;Save mm0 on Stack
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mov edx, [esp + 12] ;edx = Address
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movq mm0, [esp + 16] ;mm0 = Value
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movq [edx], mm0 ;[Address] = Value
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movq mm0, [esp] ;Restore mm0
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emms
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mov eax, [esp + 16] ;eax = Value[31:0]
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mov edx, [esp + 20] ;edx = Value[64:32]
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add esp, 8
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ret
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