drivers/gpu/drm/vmwgfx/vmwgfx_msg.h

   1 /*
   2  * Copyright (C) 2016, VMware, Inc.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation; either version 2 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful, but
  10  * WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  12  * NON INFRINGEMENT.  See the GNU General Public License for more
  13  * details.
  14  *
  15  * Based on code from vmware.c and vmmouse.c.
  16  * Author:
  17  *   Sinclair Yeh <syeh@vmware.com>
  18  */
  19 #ifndef _VMWGFX_MSG_H
  20 #define _VMWGFX_MSG_H
  21
  22
  23 /**
  24  * Hypervisor-specific bi-directional communication channel.  Should never
  25  * execute on bare metal hardware.  The caller must make sure to check for
  26  * supported hypervisor before using these macros.
  27  *
  28  * The last two parameters are both input and output and must be initialized.
  29  *
  30  * @cmd: [IN] Message Cmd
  31  * @in_ebx: [IN] Message Len, through EBX
  32  * @in_si: [IN] Input argument through SI, set to 0 if not used
  33  * @in_di: [IN] Input argument through DI, set ot 0 if not used
  34  * @port_num: [IN] port number + [channel id]
  35  * @magic: [IN] hypervisor magic value
  36  * @eax: [OUT] value of EAX register
  37  * @ebx: [OUT] e.g. status from an HB message status command
  38  * @ecx: [OUT] e.g. status from a non-HB message status command
  39  * @edx: [OUT] e.g. channel id
  40  * @si:  [OUT]
  41  * @di:  [OUT]
  42  */
  43 #define VMW_PORT(cmd, in_ebx, in_si, in_di,     \
  44                  port_num, magic,               \
  45                  eax, ebx, ecx, edx, si, di)    \
  46 ({                                              \
  47         asm volatile ("inl %%dx, %%eax;" :      \
  48                 "=a"(eax),                      \
  49                 "=b"(ebx),                      \
  50                 "=c"(ecx),                      \
  51                 "=d"(edx),                      \
  52                 "=S"(si),                       \
  53                 "=D"(di) :                      \
  54                 "a"(magic),                     \
  55                 "b"(in_ebx),                    \
  56                 "c"(cmd),                       \
  57                 "d"(port_num),                  \
  58                 "S"(in_si),                     \
  59                 "D"(in_di) :                    \
  60                 "memory");                      \
  61 })
  62
  63
  64 /**
  65  * Hypervisor-specific bi-directional communication channel.  Should never
  66  * execute on bare metal hardware.  The caller must make sure to check for
  67  * supported hypervisor before using these macros.
  68  *
  69  * The last 3 parameters are both input and output and must be initialized.
  70  *
  71  * @cmd: [IN] Message Cmd
  72  * @in_ecx: [IN] Message Len, through ECX
  73  * @in_si: [IN] Input argument through SI, set to 0 if not used
  74  * @in_di: [IN] Input argument through DI, set to 0 if not used
  75  * @port_num: [IN] port number + [channel id]
  76  * @magic: [IN] hypervisor magic value
  77  * @bp:  [IN]
  78  * @eax: [OUT] value of EAX register
  79  * @ebx: [OUT] e.g. status from an HB message status command
  80  * @ecx: [OUT] e.g. status from a non-HB message status command
  81  * @edx: [OUT] e.g. channel id
  82  * @si:  [OUT]
  83  * @di:  [OUT]
  84  */
  85 #ifdef __x86_64__
  86
  87 #define VMW_PORT_HB_OUT(cmd, in_ecx, in_si, in_di,      \
  88                         port_num, magic, bp,            \
  89                         eax, ebx, ecx, edx, si, di)     \
  90 ({                                                      \
  91         asm volatile ("push %%rbp;"                     \
  92                 "mov %12, %%rbp;"                       \
  93                 "rep outsb;"                            \
  94                 "pop %%rbp;" :                          \
  95                 "=a"(eax),                              \
  96                 "=b"(ebx),                              \
  97                 "=c"(ecx),                              \
  98                 "=d"(edx),                              \
  99                 "=S"(si),                               \
 100                 "=D"(di) :                              \
 101                 "a"(magic),                             \
 102                 "b"(cmd),                               \
 103                 "c"(in_ecx),                            \
 104                 "d"(port_num),                          \
 105                 "S"(in_si),                             \
 106                 "D"(in_di),                             \
 107                 "r"(bp) :                               \
 108                 "memory", "cc");                        \
 109 })
 110
 111
 112 #define VMW_PORT_HB_IN(cmd, in_ecx, in_si, in_di,       \
 113                        port_num, magic, bp,             \
 114                        eax, ebx, ecx, edx, si, di)      \
 115 ({                                                      \
 116         asm volatile ("push %%rbp;"                     \
 117                 "mov %12, %%rbp;"                       \
 118                 "rep insb;"                             \
 119                 "pop %%rbp" :                           \
 120                 "=a"(eax),                              \
 121                 "=b"(ebx),                              \
 122                 "=c"(ecx),                              \
 123                 "=d"(edx),                              \
 124                 "=S"(si),                               \
 125                 "=D"(di) :                              \
 126                 "a"(magic),                             \
 127                 "b"(cmd),                               \
 128                 "c"(in_ecx),                            \
 129                 "d"(port_num),                          \
 130                 "S"(in_si),                             \
 131                 "D"(in_di),                             \
 132                 "r"(bp) :                               \
 133                 "memory", "cc");                        \
 134 })
 135
 136 #else
 137
 138 /*
 139  * In the 32-bit version of this macro, we store bp in a memory location
 140  * because we've ran out of registers.
 141  * Now we can't reference that memory location while we've modified
 142  * %esp or %ebp, so we first push it on the stack, just before we push
 143  * %ebp, and then when we need it we read it from the stack where we
 144  * just pushed it.
 145  */
 146 #define VMW_PORT_HB_OUT(cmd, in_ecx, in_si, in_di,      \
 147                         port_num, magic, bp,            \
 148                         eax, ebx, ecx, edx, si, di)     \
 149 ({                                                      \
 150         asm volatile ("push %12;"                       \
 151                 "push %%ebp;"                           \
 152                 "mov 0x04(%%esp), %%ebp;"               \
 153                 "rep outsb;"                            \
 154                 "pop %%ebp;"                            \
 155                 "add $0x04, %%esp;" :                   \
 156                 "=a"(eax),                              \
 157                 "=b"(ebx),                              \
 158                 "=c"(ecx),                              \
 159                 "=d"(edx),                              \
 160                 "=S"(si),                               \
 161                 "=D"(di) :                              \
 162                 "a"(magic),                             \
 163                 "b"(cmd),                               \
 164                 "c"(in_ecx),                            \
 165                 "d"(port_num),                          \
 166                 "S"(in_si),                             \
 167                 "D"(in_di),                             \
 168                 "m"(bp) :                               \
 169                 "memory", "cc");                        \
 170 })
 171
 172
 173 #define VMW_PORT_HB_IN(cmd, in_ecx, in_si, in_di,       \
 174                        port_num, magic, bp,             \
 175                        eax, ebx, ecx, edx, si, di)      \
 176 ({                                                      \
 177         asm volatile ("push %12;"                       \
 178                 "push %%ebp;"                           \
 179                 "mov 0x04(%%esp), %%ebp;"               \
 180                 "rep insb;"                             \
 181                 "pop %%ebp;"                            \
 182                 "add $0x04, %%esp;" :                   \
 183                 "=a"(eax),                              \
 184                 "=b"(ebx),                              \
 185                 "=c"(ecx),                              \
 186                 "=d"(edx),                              \
 187                 "=S"(si),                               \
 188                 "=D"(di) :                              \
 189                 "a"(magic),                             \
 190                 "b"(cmd),                               \
 191                 "c"(in_ecx),                            \
 192                 "d"(port_num),                          \
 193                 "S"(in_si),                             \
 194                 "D"(in_di),                             \
 195                 "m"(bp) :                               \
 196                 "memory", "cc");                        \
 197 })
 198 #endif /* #if __x86_64__ */
 199
 200 #endif