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 */ 93