MdePkg/Library/BaseIoLibIntrinsic/X64/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     DEFAULT REL
  17     SECTION .text
  18
  19 ;------------------------------------------------------------------------------
  20 ; Check whether we need to unroll the String I/O in SEV guest
  21 ;
  22 ; Return // eax   (1 - unroll, 0 - no unroll)
  23 ;------------------------------------------------------------------------------
  24 global ASM_PFX(SevNoRepIo)
  25 ASM_PFX(SevNoRepIo):
  26
  27   ; CPUID clobbers ebx, ecx and edx
  28   push      rbx
  29   push      rcx
  30   push      rdx
  31
  32   ; Check if we are runing under hypervisor
  33   ; CPUID(1).ECX Bit 31
  34   mov       eax, 1
  35   cpuid
  36   bt        ecx, 31
  37   jnc       @UseRepIo
  38
  39   ; Check if we have Memory encryption CPUID leaf
  40   mov       eax, 0x80000000
  41   cpuid
  42   cmp       eax, 0x8000001f
  43   jl        @UseRepIo
  44
  45   ; Check for memory encryption feature:
  46   ;  CPUID  Fn8000_001F[EAX] - Bit 1
  47   ;
  48   mov       eax,  0x8000001f
  49   cpuid
  50   bt        eax, 1
  51   jnc       @UseRepIo
  52
  53   ; Check if memory encryption is enabled
  54   ;  MSR_0xC0010131 - Bit 0 (SEV enabled)
  55   ;  MSR_0xC0010131 - Bit 1 (SEV-ES enabled)
  56   mov       ecx, 0xc0010131
  57   rdmsr
  58
  59   ; Check for (SevEsEnabled == 0 && SevEnabled == 1)
  60   and       eax, 3
  61   cmp       eax, 1
  62   je        @SevNoRepIo_Done
  63
  64 @UseRepIo:
  65   xor       eax, eax
  66
  67 @SevNoRepIo_Done:
  68   pop       rdx
  69   pop       rcx
  70   pop       rbx
  71   ret
  72
  73 ;------------------------------------------------------------------------------
  74 ;  VOID
  75 ;  EFIAPI
  76 ;  IoReadFifo8 (
  77 ;    IN  UINTN                 Port,              // rcx
  78 ;    IN  UINTN                 Size,              // rdx
  79 ;    OUT VOID                  *Buffer            // r8
  80 ;    );
  81 ;------------------------------------------------------------------------------
  82 global ASM_PFX(IoReadFifo8)
  83 ASM_PFX(IoReadFifo8):
  84     xchg    rcx, rdx
  85     xchg    rdi, r8             ; rdi: buffer address; r8: save rdi
  86
  87     ; Check if we need to unroll String I/O
  88     call    ASM_PFX(SevNoRepIo)
  89     test    eax, eax
  90     jnz     @IoReadFifo8_NoRep
  91
  92     cld
  93     rep     insb
  94     jmp     @IoReadFifo8_Done
  95
  96 @IoReadFifo8_NoRep:
  97     jrcxz   @IoReadFifo8_Done
  98
  99 @IoReadFifo8_Loop:
 100     in      al, dx
 101     mov     byte [rdi], al
 102     inc     rdi
 103     loop    @IoReadFifo8_Loop
 104
 105 @IoReadFifo8_Done:
 106     mov     rdi, r8             ; restore rdi
 107     ret
 108
 109 ;------------------------------------------------------------------------------
 110 ;  VOID
 111 ;  EFIAPI
 112 ;  IoReadFifo16 (
 113 ;    IN  UINTN                 Port,              // rcx
 114 ;    IN  UINTN                 Size,              // rdx
 115 ;    OUT VOID                  *Buffer            // r8
 116 ;    );
 117 ;------------------------------------------------------------------------------
 118 global ASM_PFX(IoReadFifo16)
 119 ASM_PFX(IoReadFifo16):
 120     xchg    rcx, rdx
 121     xchg    rdi, r8             ; rdi: buffer address; r8: save rdi
 122
 123     ; Check if we need to unroll String I/O
 124     call    ASM_PFX(SevNoRepIo)
 125     test    eax, eax
 126     jnz     @IoReadFifo16_NoRep
 127
 128     cld
 129     rep     insw
 130     jmp     @IoReadFifo16_Done
 131
 132 @IoReadFifo16_NoRep:
 133     jrcxz   @IoReadFifo16_Done
 134
 135 @IoReadFifo16_Loop:
 136     in      ax, dx
 137     mov     word [rdi], ax
 138     add     rdi, 2
 139     loop    @IoReadFifo16_Loop
 140
 141 @IoReadFifo16_Done:
 142     mov     rdi, r8             ; restore rdi
 143     ret
 144
 145 ;------------------------------------------------------------------------------
 146 ;  VOID
 147 ;  EFIAPI
 148 ;  IoReadFifo32 (
 149 ;    IN  UINTN                 Port,              // rcx
 150 ;    IN  UINTN                 Size,              // rdx
 151 ;    OUT VOID                  *Buffer            // r8
 152 ;    );
 153 ;------------------------------------------------------------------------------
 154 global ASM_PFX(IoReadFifo32)
 155 ASM_PFX(IoReadFifo32):
 156     xchg    rcx, rdx
 157     xchg    rdi, r8             ; rdi: buffer address; r8: save rdi
 158
 159     ; Check if we need to unroll String I/O
 160     call    ASM_PFX(SevNoRepIo)
 161     test    eax, eax
 162     jnz     @IoReadFifo32_NoRep
 163
 164     cld
 165     rep     insd
 166     jmp     @IoReadFifo32_Done
 167
 168 @IoReadFifo32_NoRep:
 169     jrcxz   @IoReadFifo32_Done
 170
 171 @IoReadFifo32_Loop:
 172     in      eax, dx
 173     mov     dword [rdi], eax
 174     add     rdi, 4
 175     loop    @IoReadFifo32_Loop
 176
 177 @IoReadFifo32_Done:
 178     mov     rdi, r8             ; restore rdi
 179     ret
 180
 181 ;------------------------------------------------------------------------------
 182 ;  VOID
 183 ;  EFIAPI
 184 ;  IoWriteFifo8 (
 185 ;    IN UINTN                  Port,              // rcx
 186 ;    IN UINTN                  Size,              // rdx
 187 ;    IN VOID                   *Buffer            // r8
 188 ;    );
 189 ;------------------------------------------------------------------------------
 190 global ASM_PFX(IoWriteFifo8)
 191 ASM_PFX(IoWriteFifo8):
 192     xchg    rcx, rdx
 193     xchg    rsi, r8             ; rsi: buffer address; r8: save rsi
 194
 195     ; Check if we need to unroll String I/O
 196     call    ASM_PFX(SevNoRepIo)
 197     test    eax, eax
 198     jnz     @IoWriteFifo8_NoRep
 199
 200     cld
 201     rep     outsb
 202     jmp     @IoWriteFifo8_Done
 203
 204 @IoWriteFifo8_NoRep:
 205     jrcxz   @IoWriteFifo8_Done
 206
 207 @IoWriteFifo8_Loop:
 208     mov     byte [rsi], al
 209     out     dx, al
 210     inc     rsi
 211     loop    @IoWriteFifo8_Loop
 212
 213 @IoWriteFifo8_Done:
 214     mov     rsi, r8             ; restore rsi
 215     ret
 216
 217 ;------------------------------------------------------------------------------
 218 ;  VOID
 219 ;  EFIAPI
 220 ;  IoWriteFifo16 (
 221 ;    IN UINTN                  Port,              // rcx
 222 ;    IN UINTN                  Size,              // rdx
 223 ;    IN VOID                   *Buffer            // r8
 224 ;    );
 225 ;------------------------------------------------------------------------------
 226 global ASM_PFX(IoWriteFifo16)
 227 ASM_PFX(IoWriteFifo16):
 228     xchg    rcx, rdx
 229     xchg    rsi, r8             ; rsi: buffer address; r8: save rsi
 230
 231     ; Check if we need to unroll String I/O
 232     call    ASM_PFX(SevNoRepIo)
 233     test    eax, eax
 234     jnz     @IoWriteFifo16_NoRep
 235
 236     cld
 237     rep     outsw
 238     jmp     @IoWriteFifo16_Done
 239
 240 @IoWriteFifo16_NoRep:
 241     jrcxz   @IoWriteFifo16_Done
 242
 243 @IoWriteFifo16_Loop:
 244     mov     word [rsi], ax
 245     out     dx, ax
 246     add     rsi, 2
 247     loop    @IoWriteFifo16_Loop
 248
 249 @IoWriteFifo16_Done:
 250     mov     rsi, r8             ; restore rsi
 251     ret
 252
 253 ;------------------------------------------------------------------------------
 254 ;  VOID
 255 ;  EFIAPI
 256 ;  IoWriteFifo32 (
 257 ;    IN UINTN                  Port,              // rcx
 258 ;    IN UINTN                  Size,              // rdx
 259 ;    IN VOID                   *Buffer            // r8
 260 ;    );
 261 ;------------------------------------------------------------------------------
 262 global ASM_PFX(IoWriteFifo32)
 263 ASM_PFX(IoWriteFifo32):
 264     xchg    rcx, rdx
 265     xchg    rsi, r8             ; rsi: buffer address; r8: save rsi
 266
 267     ; Check if we need to unroll String I/O
 268     call    ASM_PFX(SevNoRepIo)
 269     test    eax, eax
 270     jnz     @IoWriteFifo32_NoRep
 271
 272     cld
 273     rep     outsd
 274     jmp     @IoWriteFifo32_Done
 275
 276 @IoWriteFifo32_NoRep:
 277     jrcxz   @IoWriteFifo32_Done
 278
 279 @IoWriteFifo32_Loop:
 280     mov     dword [rsi], eax
 281     out     dx, eax
 282     add     rsi, 4
 283     loop    @IoWriteFifo32_Loop
 284
 285 @IoWriteFifo32_Done:
 286     mov     rsi, r8             ; restore rsi
 287     ret
 288