MdePkg/Library/BaseIoLibIntrinsic/Ia32/IoFifoSev.nasm

   1 ;------------------------------------------------------------------------------
   2 ;
   3 ; Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
   4 ; Copyright (c) 2017, AMD Incorporated. All rights reserved.<BR>
   5 ;
   6 ; This program and the accompanying materials are licensed and made available
   7 ; under the terms and conditions of the BSD License which accompanies this
   8 ; distribution.  The full text of the license may be found at
   9 ; http://opensource.org/licenses/bsd-license.php.
  10 ;
  11 ; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  12 ; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  13 ;
  14 ;------------------------------------------------------------------------------
  15
  16     SECTION .text
  17
  18 ;------------------------------------------------------------------------------
  19 ; Check whether we need to unroll the String I/O under SEV guest
  20 ;
  21 ; Return // eax   (1 - unroll, 0 - no unroll)
  22 ;------------------------------------------------------------------------------
  23 global ASM_PFX(SevNoRepIo)
  24 ASM_PFX(SevNoRepIo):
  25
  26   ; CPUID clobbers ebx, ecx and edx
  27   push      ebx
  28   push      ecx
  29   push      edx
  30
  31   ; Check if we are running under hypervisor
  32   ; CPUID(1).ECX Bit 31
  33   mov       eax, 1
  34   cpuid
  35   bt        ecx, 31
  36   jnc       @UseRepIo
  37
  38   ; Check if we have Memory encryption CPUID leaf
  39   mov       eax, 0x80000000
  40   cpuid
  41   cmp       eax, 0x8000001f
  42   jl        @UseRepIo
  43
  44   ; Check for memory encryption feature:
  45   ;  CPUID  Fn8000_001F[EAX] - Bit 1
  46   ;
  47   mov       eax,  0x8000001f
  48   cpuid
  49   bt        eax, 1
  50   jnc       @UseRepIo
  51
  52   ; Check if memory encryption is enabled
  53   ;  MSR_0xC0010131 - Bit 0 (SEV enabled)
  54   ;  MSR_0xC0010131 - Bit 1 (SEV-ES enabled)
  55   mov       ecx, 0xc0010131
  56   rdmsr
  57
  58   ; Check for (SevEsEnabled == 0 && SevEnabled == 1)
  59   and       eax, 3
  60   cmp       eax, 1
  61   je        @SevNoRepIo_Done
  62
  63 @UseRepIo:
  64   xor       eax, eax
  65
  66 @SevNoRepIo_Done:
  67   pop       edx
  68   pop       ecx
  69   pop       ebx
  70   ret
  71
  72 ;------------------------------------------------------------------------------
  73 ;  VOID
  74 ;  EFIAPI
  75 ;  IoReadFifo8 (
  76 ;    IN  UINTN                 Port,
  77 ;    IN  UINTN                 Size,
  78 ;    OUT VOID                  *Buffer
  79 ;    );
  80 ;------------------------------------------------------------------------------
  81 global ASM_PFX(IoReadFifo8)
  82 ASM_PFX(IoReadFifo8):
  83     push    edi
  84     mov     dx, [esp + 8]
  85     mov     ecx, [esp + 12]
  86     mov     edi, [esp + 16]
  87
  88     ; Check if we need to unroll String I/O
  89     call    ASM_PFX(SevNoRepIo)
  90     test    eax, eax
  91     jnz     @IoReadFifo8_NoRep
  92
  93     cld
  94     rep     insb
  95     jmp     @IoReadFifo8_Done
  96
  97 @IoReadFifo8_NoRep:
  98     jecxz   @IoReadFifo8_Done
  99
 100 @IoReadFifo8_Loop:
 101     in      al, dx
 102     mov     byte [edi], al
 103     inc     edi
 104     loop    @IoReadFifo8_Loop
 105
 106 @IoReadFifo8_Done:
 107     pop     edi
 108     ret
 109
 110 ;------------------------------------------------------------------------------
 111 ;  VOID
 112 ;  EFIAPI
 113 ;  IoReadFifo16 (
 114 ;    IN  UINTN                 Port,
 115 ;    IN  UINTN                 Size,
 116 ;    OUT VOID                  *Buffer
 117 ;    );
 118 ;------------------------------------------------------------------------------
 119 global ASM_PFX(IoReadFifo16)
 120 ASM_PFX(IoReadFifo16):
 121     push    edi
 122     mov     dx, [esp + 8]
 123     mov     ecx, [esp + 12]
 124     mov     edi, [esp + 16]
 125
 126     ; Check if we need to unroll String I/O
 127     call    ASM_PFX(SevNoRepIo)
 128     test    eax, eax
 129     jnz     @IoReadFifo16_NoRep
 130
 131     cld
 132     rep     insw
 133     jmp     @IoReadFifo16_Done
 134
 135 @IoReadFifo16_NoRep:
 136     jecxz   @IoReadFifo16_Done
 137
 138 @IoReadFifo16_Loop:
 139     in      ax, dx
 140     mov     word [edi], ax
 141     add     edi, 2
 142     loop    @IoReadFifo16_Loop
 143
 144 @IoReadFifo16_Done:
 145     pop     edi
 146     ret
 147
 148 ;------------------------------------------------------------------------------
 149 ;  VOID
 150 ;  EFIAPI
 151 ;  IoReadFifo32 (
 152 ;    IN  UINTN                 Port,
 153 ;    IN  UINTN                 Size,
 154 ;    OUT VOID                  *Buffer
 155 ;    );
 156 ;------------------------------------------------------------------------------
 157 global ASM_PFX(IoReadFifo32)
 158 ASM_PFX(IoReadFifo32):
 159     push    edi
 160     mov     dx, [esp + 8]
 161     mov     ecx, [esp + 12]
 162     mov     edi, [esp + 16]
 163
 164     ; Check if we need to unroll String I/O
 165     call    ASM_PFX(SevNoRepIo)
 166     test    eax, eax
 167     jnz     @IoReadFifo32_NoRep
 168
 169     cld
 170     rep     insd
 171     jmp     @IoReadFifo32_Done
 172
 173 @IoReadFifo32_NoRep:
 174     jecxz   @IoReadFifo32_Done
 175
 176 @IoReadFifo32_Loop:
 177     in      eax, dx
 178     mov     dword [edi], eax
 179     add     edi, 4
 180     loop    @IoReadFifo32_Loop
 181
 182 @IoReadFifo32_Done:
 183     pop     edi
 184     ret
 185
 186 ;------------------------------------------------------------------------------
 187 ;  VOID
 188 ;  EFIAPI
 189 ;  IoWriteFifo8 (
 190 ;    IN UINTN                  Port,
 191 ;    IN UINTN                  Size,
 192 ;    IN VOID                   *Buffer
 193 ;    );
 194 ;------------------------------------------------------------------------------
 195 global ASM_PFX(IoWriteFifo8)
 196 ASM_PFX(IoWriteFifo8):
 197     push    esi
 198     mov     dx, [esp + 8]
 199     mov     ecx, [esp + 12]
 200     mov     esi, [esp + 16]
 201
 202     ; Check if we need to unroll String I/O
 203     call    ASM_PFX(SevNoRepIo)
 204     test    eax, eax
 205     jnz     @IoWriteFifo8_NoRep
 206
 207     cld
 208     rep     outsb
 209     jmp     @IoWriteFifo8_Done
 210
 211 @IoWriteFifo8_NoRep:
 212     jecxz   @IoWriteFifo8_Done
 213
 214 @IoWriteFifo8_Loop:
 215     mov     byte [esi], al
 216     out     dx, al
 217     inc     esi
 218     loop    @IoWriteFifo8_Loop
 219
 220 @IoWriteFifo8_Done:
 221     pop     esi
 222     ret
 223
 224 ;------------------------------------------------------------------------------
 225 ;  VOID
 226 ;  EFIAPI
 227 ;  IoWriteFifo16 (
 228 ;    IN UINTN                  Port,
 229 ;    IN UINTN                  Size,
 230 ;    IN VOID                   *Buffer
 231 ;    );
 232 ;------------------------------------------------------------------------------
 233 global ASM_PFX(IoWriteFifo16)
 234 ASM_PFX(IoWriteFifo16):
 235     push    esi
 236     mov     dx, [esp + 8]
 237     mov     ecx, [esp + 12]
 238     mov     esi, [esp + 16]
 239
 240     ; Check if we need to unroll String I/O
 241     call    ASM_PFX(SevNoRepIo)
 242     test    eax, eax
 243     jnz     @IoWriteFifo16_NoRep
 244
 245     cld
 246     rep     outsw
 247     jmp     @IoWriteFifo16_Done
 248
 249 @IoWriteFifo16_NoRep:
 250     jecxz   @IoWriteFifo16_Done
 251
 252 @IoWriteFifo16_Loop:
 253     mov     word [esi], ax
 254     out     dx, ax
 255     add     esi, 2
 256     loop    @IoWriteFifo16_Loop
 257
 258 @IoWriteFifo16_Done:
 259     pop     esi
 260     ret
 261
 262 ;------------------------------------------------------------------------------
 263 ;  VOID
 264 ;  EFIAPI
 265 ;  IoWriteFifo32 (
 266 ;    IN UINTN                  Port,
 267 ;    IN UINTN                  Size,
 268 ;    IN VOID                   *Buffer
 269 ;    );
 270 ;------------------------------------------------------------------------------
 271 global ASM_PFX(IoWriteFifo32)
 272 ASM_PFX(IoWriteFifo32):
 273     push    esi
 274     mov     dx, [esp + 8]
 275     mov     ecx, [esp + 12]
 276     mov     esi, [esp + 16]
 277
 278     ; Check if we need to unroll String I/O
 279     call    ASM_PFX(SevNoRepIo)
 280     test    eax, eax
 281     jnz     @IoWriteFifo32_NoRep
 282
 283     cld
 284     rep     outsd
 285     jmp     @IoWriteFifo32_Done
 286
 287 @IoWriteFifo32_NoRep:
 288     jecxz   @IoWriteFifo32_Done
 289
 290 @IoWriteFifo32_Loop:
 291     mov     dword [esi], eax
 292     out     dx, eax
 293     add     esi, 4
 294     loop    @IoWriteFifo32_Loop
 295
 296 @IoWriteFifo32_Done:
 297     pop     esi
 298     ret
 299