| 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 */ |