pc-bios/optionrom/optrom_fw_cfg.h

   1 /*
   2  * Common Option ROM Functions for fw_cfg
   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,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  16  *
  17  * Copyright (c) 2015-2019 Red Hat Inc.
  18  *   Authors:
  19  *     Marc Marí <marc.mari.barcelo@gmail.com>
  20  *     Richard W.M. Jones <rjones@redhat.com>
  21  *     Stefano Garzarella <sgarzare@redhat.com>
  22  */
  23
  24 #ifndef OPTROM_FW_CFG_H
  25 #define OPTROM_FW_CFG_H
  26
  27 #include "../../include/standard-headers/linux/qemu_fw_cfg.h"
  28
  29 #define BIOS_CFG_IOPORT_CFG     0x510
  30 #define BIOS_CFG_IOPORT_DATA    0x511
  31 #define BIOS_CFG_DMA_ADDR_HIGH  0x514
  32 #define BIOS_CFG_DMA_ADDR_LOW   0x518
  33
  34 static __attribute__((unused))
  35 void bios_cfg_select(uint16_t key)
  36 {
  37     outw(key, BIOS_CFG_IOPORT_CFG);
  38 }
  39
  40 static __attribute__((unused))
  41 void bios_cfg_read_entry_io(void *buf, uint16_t entry, uint32_t len)
  42 {
  43     bios_cfg_select(entry);
  44     insb(BIOS_CFG_IOPORT_DATA, buf, len);
  45 }
  46
  47 /*
  48  * clang is happy to inline this function, and bloats the
  49  * ROM.
  50  */
  51 static __attribute__((__noinline__)) __attribute__((unused))
  52 void bios_cfg_read_entry_dma(void *buf, uint16_t entry, uint32_t len)
  53 {
  54     struct fw_cfg_dma_access access;
  55     uint32_t control = (entry << 16) | FW_CFG_DMA_CTL_SELECT
  56                         | FW_CFG_DMA_CTL_READ;
  57
  58     access.address = cpu_to_be64((uint64_t)(uint32_t)buf);
  59     access.length = cpu_to_be32(len);
  60     access.control = cpu_to_be32(control);
  61
  62     barrier();
  63
  64     outl(cpu_to_be32((uint32_t)&access), BIOS_CFG_DMA_ADDR_LOW);
  65
  66     while (be32_to_cpu(access.control) & ~FW_CFG_DMA_CTL_ERROR) {
  67         barrier();
  68     }
  69 }
  70
  71 static __attribute__((unused))
  72 void bios_cfg_read_entry(void *buf, uint16_t entry, uint32_t len,
  73                          uint32_t version)
  74 {
  75     if (version & FW_CFG_VERSION_DMA) {
  76         bios_cfg_read_entry_dma(buf, entry, len);
  77     } else {
  78         bios_cfg_read_entry_io(buf, entry, len);
  79     }
  80 }
  81
  82 static __attribute__((unused))
  83 uint32_t bios_cfg_version(void)
  84 {
  85     uint32_t version;
  86
  87     bios_cfg_read_entry_io(&version, FW_CFG_ID, sizeof(version));
  88
  89     return version;
  90 }
  91
  92 #endif /* OPTROM_FW_CFG_H */