diff options
Diffstat (limited to 'MdePkg/Library/BaseIoLibIntrinsic/Ia32/IoFifoSev.nasm')
| -rw-r--r-- | MdePkg/Library/BaseIoLibIntrinsic/Ia32/IoFifoSev.nasm | 293 |
1 files changed, 293 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseIoLibIntrinsic/Ia32/IoFifoSev.nasm b/MdePkg/Library/BaseIoLibIntrinsic/Ia32/IoFifoSev.nasm new file mode 100644 index 000000000000..3a7a25bb2716 --- /dev/null +++ b/MdePkg/Library/BaseIoLibIntrinsic/Ia32/IoFifoSev.nasm @@ -0,0 +1,293 @@ +;------------------------------------------------------------------------------ +; +; Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR> +; Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR> +; +; SPDX-License-Identifier: BSD-2-Clause-Patent +; +;------------------------------------------------------------------------------ + + SECTION .text + +;------------------------------------------------------------------------------ +; Check whether we need to unroll the String I/O under SEV guest +; +; Return // eax (1 - unroll, 0 - no unroll) +;------------------------------------------------------------------------------ +global ASM_PFX(SevNoRepIo) +ASM_PFX(SevNoRepIo): + + ; CPUID clobbers ebx, ecx and edx + push ebx + push ecx + push edx + + ; Check if we are running under hypervisor + ; CPUID(1).ECX Bit 31 + mov eax, 1 + cpuid + bt ecx, 31 + jnc @UseRepIo + + ; Check if we have Memory encryption CPUID leaf + mov eax, 0x80000000 + cpuid + cmp eax, 0x8000001f + jl @UseRepIo + + ; Check for memory encryption feature: + ; CPUID Fn8000_001F[EAX] - Bit 1 + ; + mov eax, 0x8000001f + cpuid + bt eax, 1 + jnc @UseRepIo + + ; Check if memory encryption is enabled + ; MSR_0xC0010131 - Bit 0 (SEV enabled) + ; MSR_0xC0010131 - Bit 1 (SEV-ES enabled) + mov ecx, 0xc0010131 + rdmsr + + ; Check for (SevEsEnabled == 0 && SevEnabled == 1) + and eax, 3 + cmp eax, 1 + je @SevNoRepIo_Done + +@UseRepIo: + xor eax, eax + +@SevNoRepIo_Done: + pop edx + pop ecx + pop ebx + ret + +;------------------------------------------------------------------------------ +; VOID +; EFIAPI +; IoReadFifo8 ( +; IN UINTN Port, +; IN UINTN Size, +; OUT VOID *Buffer +; ); +;------------------------------------------------------------------------------ +global ASM_PFX(IoReadFifo8) +ASM_PFX(IoReadFifo8): + push edi + mov dx, [esp + 8] + mov ecx, [esp + 12] + mov edi, [esp + 16] + + ; Check if we need to unroll String I/O + call ASM_PFX(SevNoRepIo) + test eax, eax + jnz @IoReadFifo8_NoRep + + cld + rep insb + jmp @IoReadFifo8_Done + +@IoReadFifo8_NoRep: + jecxz @IoReadFifo8_Done + +@IoReadFifo8_Loop: + in al, dx + mov byte [edi], al + inc edi + loop @IoReadFifo8_Loop + +@IoReadFifo8_Done: + pop edi + ret + +;------------------------------------------------------------------------------ +; VOID +; EFIAPI +; IoReadFifo16 ( +; IN UINTN Port, +; IN UINTN Size, +; OUT VOID *Buffer +; ); +;------------------------------------------------------------------------------ +global ASM_PFX(IoReadFifo16) +ASM_PFX(IoReadFifo16): + push edi + mov dx, [esp + 8] + mov ecx, [esp + 12] + mov edi, [esp + 16] + + ; Check if we need to unroll String I/O + call ASM_PFX(SevNoRepIo) + test eax, eax + jnz @IoReadFifo16_NoRep + + cld + rep insw + jmp @IoReadFifo16_Done + +@IoReadFifo16_NoRep: + jecxz @IoReadFifo16_Done + +@IoReadFifo16_Loop: + in ax, dx + mov word [edi], ax + add edi, 2 + loop @IoReadFifo16_Loop + +@IoReadFifo16_Done: + pop edi + ret + +;------------------------------------------------------------------------------ +; VOID +; EFIAPI +; IoReadFifo32 ( +; IN UINTN Port, +; IN UINTN Size, +; OUT VOID *Buffer +; ); +;------------------------------------------------------------------------------ +global ASM_PFX(IoReadFifo32) +ASM_PFX(IoReadFifo32): + push edi + mov dx, [esp + 8] + mov ecx, [esp + 12] + mov edi, [esp + 16] + + ; Check if we need to unroll String I/O + call ASM_PFX(SevNoRepIo) + test eax, eax + jnz @IoReadFifo32_NoRep + + cld + rep insd + jmp @IoReadFifo32_Done + +@IoReadFifo32_NoRep: + jecxz @IoReadFifo32_Done + +@IoReadFifo32_Loop: + in eax, dx + mov dword [edi], eax + add edi, 4 + loop @IoReadFifo32_Loop + +@IoReadFifo32_Done: + pop edi + ret + +;------------------------------------------------------------------------------ +; VOID +; EFIAPI +; IoWriteFifo8 ( +; IN UINTN Port, +; IN UINTN Size, +; IN VOID *Buffer +; ); +;------------------------------------------------------------------------------ +global ASM_PFX(IoWriteFifo8) +ASM_PFX(IoWriteFifo8): + push esi + mov dx, [esp + 8] + mov ecx, [esp + 12] + mov esi, [esp + 16] + + ; Check if we need to unroll String I/O + call ASM_PFX(SevNoRepIo) + test eax, eax + jnz @IoWriteFifo8_NoRep + + cld + rep outsb + jmp @IoWriteFifo8_Done + +@IoWriteFifo8_NoRep: + jecxz @IoWriteFifo8_Done + +@IoWriteFifo8_Loop: + mov al, byte [esi] + out dx, al + inc esi + loop @IoWriteFifo8_Loop + +@IoWriteFifo8_Done: + pop esi + ret + +;------------------------------------------------------------------------------ +; VOID +; EFIAPI +; IoWriteFifo16 ( +; IN UINTN Port, +; IN UINTN Size, +; IN VOID *Buffer +; ); +;------------------------------------------------------------------------------ +global ASM_PFX(IoWriteFifo16) +ASM_PFX(IoWriteFifo16): + push esi + mov dx, [esp + 8] + mov ecx, [esp + 12] + mov esi, [esp + 16] + + ; Check if we need to unroll String I/O + call ASM_PFX(SevNoRepIo) + test eax, eax + jnz @IoWriteFifo16_NoRep + + cld + rep outsw + jmp @IoWriteFifo16_Done + +@IoWriteFifo16_NoRep: + jecxz @IoWriteFifo16_Done + +@IoWriteFifo16_Loop: + mov ax, word [esi] + out dx, ax + add esi, 2 + loop @IoWriteFifo16_Loop + +@IoWriteFifo16_Done: + pop esi + ret + +;------------------------------------------------------------------------------ +; VOID +; EFIAPI +; IoWriteFifo32 ( +; IN UINTN Port, +; IN UINTN Size, +; IN VOID *Buffer +; ); +;------------------------------------------------------------------------------ +global ASM_PFX(IoWriteFifo32) +ASM_PFX(IoWriteFifo32): + push esi + mov dx, [esp + 8] + mov ecx, [esp + 12] + mov esi, [esp + 16] + + ; Check if we need to unroll String I/O + call ASM_PFX(SevNoRepIo) + test eax, eax + jnz @IoWriteFifo32_NoRep + + cld + rep outsd + jmp @IoWriteFifo32_Done + +@IoWriteFifo32_NoRep: + jecxz @IoWriteFifo32_Done + +@IoWriteFifo32_Loop: + mov eax, dword [esi] + out dx, eax + add esi, 4 + loop @IoWriteFifo32_Loop + +@IoWriteFifo32_Done: + pop esi + ret + |