1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only 2*4882a593Smuzhiyun /* 3*4882a593Smuzhiyun * Copyright 2007-2010 Red Hat, Inc. 4*4882a593Smuzhiyun * by Peter Jones <pjones@redhat.com> 5*4882a593Smuzhiyun * Copyright 2007 IBM, Inc. 6*4882a593Smuzhiyun * by Konrad Rzeszutek <konradr@linux.vnet.ibm.com> 7*4882a593Smuzhiyun * Copyright 2008 8*4882a593Smuzhiyun * by Konrad Rzeszutek <ketuzsezr@darnok.org> 9*4882a593Smuzhiyun * 10*4882a593Smuzhiyun * This code finds the iSCSI Boot Format Table. 11*4882a593Smuzhiyun */ 12*4882a593Smuzhiyun 13*4882a593Smuzhiyun #include <linux/memblock.h> 14*4882a593Smuzhiyun #include <linux/blkdev.h> 15*4882a593Smuzhiyun #include <linux/ctype.h> 16*4882a593Smuzhiyun #include <linux/device.h> 17*4882a593Smuzhiyun #include <linux/efi.h> 18*4882a593Smuzhiyun #include <linux/err.h> 19*4882a593Smuzhiyun #include <linux/init.h> 20*4882a593Smuzhiyun #include <linux/limits.h> 21*4882a593Smuzhiyun #include <linux/module.h> 22*4882a593Smuzhiyun #include <linux/pci.h> 23*4882a593Smuzhiyun #include <linux/stat.h> 24*4882a593Smuzhiyun #include <linux/string.h> 25*4882a593Smuzhiyun #include <linux/types.h> 26*4882a593Smuzhiyun #include <linux/acpi.h> 27*4882a593Smuzhiyun #include <linux/iscsi_ibft.h> 28*4882a593Smuzhiyun 29*4882a593Smuzhiyun #include <asm/mmzone.h> 30*4882a593Smuzhiyun 31*4882a593Smuzhiyun /* 32*4882a593Smuzhiyun * Physical location of iSCSI Boot Format Table. 33*4882a593Smuzhiyun */ 34*4882a593Smuzhiyun struct acpi_table_ibft *ibft_addr; 35*4882a593Smuzhiyun EXPORT_SYMBOL_GPL(ibft_addr); 36*4882a593Smuzhiyun 37*4882a593Smuzhiyun static const struct { 38*4882a593Smuzhiyun char *sign; 39*4882a593Smuzhiyun } ibft_signs[] = { 40*4882a593Smuzhiyun { "iBFT" }, 41*4882a593Smuzhiyun { "BIFT" }, /* Broadcom iSCSI Offload */ 42*4882a593Smuzhiyun }; 43*4882a593Smuzhiyun 44*4882a593Smuzhiyun #define IBFT_SIGN_LEN 4 45*4882a593Smuzhiyun #define IBFT_START 0x80000 /* 512kB */ 46*4882a593Smuzhiyun #define IBFT_END 0x100000 /* 1MB */ 47*4882a593Smuzhiyun #define VGA_MEM 0xA0000 /* VGA buffer */ 48*4882a593Smuzhiyun #define VGA_SIZE 0x20000 /* 128kB */ 49*4882a593Smuzhiyun find_ibft_in_mem(void)50*4882a593Smuzhiyunstatic int __init find_ibft_in_mem(void) 51*4882a593Smuzhiyun { 52*4882a593Smuzhiyun unsigned long pos; 53*4882a593Smuzhiyun unsigned int len = 0; 54*4882a593Smuzhiyun void *virt; 55*4882a593Smuzhiyun int i; 56*4882a593Smuzhiyun 57*4882a593Smuzhiyun for (pos = IBFT_START; pos < IBFT_END; pos += 16) { 58*4882a593Smuzhiyun /* The table can't be inside the VGA BIOS reserved space, 59*4882a593Smuzhiyun * so skip that area */ 60*4882a593Smuzhiyun if (pos == VGA_MEM) 61*4882a593Smuzhiyun pos += VGA_SIZE; 62*4882a593Smuzhiyun virt = isa_bus_to_virt(pos); 63*4882a593Smuzhiyun 64*4882a593Smuzhiyun for (i = 0; i < ARRAY_SIZE(ibft_signs); i++) { 65*4882a593Smuzhiyun if (memcmp(virt, ibft_signs[i].sign, IBFT_SIGN_LEN) == 66*4882a593Smuzhiyun 0) { 67*4882a593Smuzhiyun unsigned long *addr = 68*4882a593Smuzhiyun (unsigned long *)isa_bus_to_virt(pos + 4); 69*4882a593Smuzhiyun len = *addr; 70*4882a593Smuzhiyun /* if the length of the table extends past 1M, 71*4882a593Smuzhiyun * the table cannot be valid. */ 72*4882a593Smuzhiyun if (pos + len <= (IBFT_END-1)) { 73*4882a593Smuzhiyun ibft_addr = (struct acpi_table_ibft *)virt; 74*4882a593Smuzhiyun pr_info("iBFT found at 0x%lx.\n", pos); 75*4882a593Smuzhiyun goto done; 76*4882a593Smuzhiyun } 77*4882a593Smuzhiyun } 78*4882a593Smuzhiyun } 79*4882a593Smuzhiyun } 80*4882a593Smuzhiyun done: 81*4882a593Smuzhiyun return len; 82*4882a593Smuzhiyun } 83*4882a593Smuzhiyun /* 84*4882a593Smuzhiyun * Routine used to find the iSCSI Boot Format Table. The logical 85*4882a593Smuzhiyun * kernel address is set in the ibft_addr global variable. 86*4882a593Smuzhiyun */ find_ibft_region(unsigned long * sizep)87*4882a593Smuzhiyununsigned long __init find_ibft_region(unsigned long *sizep) 88*4882a593Smuzhiyun { 89*4882a593Smuzhiyun ibft_addr = NULL; 90*4882a593Smuzhiyun 91*4882a593Smuzhiyun /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will 92*4882a593Smuzhiyun * only use ACPI for this */ 93*4882a593Smuzhiyun 94*4882a593Smuzhiyun if (!efi_enabled(EFI_BOOT)) 95*4882a593Smuzhiyun find_ibft_in_mem(); 96*4882a593Smuzhiyun 97*4882a593Smuzhiyun if (ibft_addr) { 98*4882a593Smuzhiyun *sizep = PAGE_ALIGN(ibft_addr->header.length); 99*4882a593Smuzhiyun return (u64)virt_to_phys(ibft_addr); 100*4882a593Smuzhiyun } 101*4882a593Smuzhiyun 102*4882a593Smuzhiyun *sizep = 0; 103*4882a593Smuzhiyun return 0; 104*4882a593Smuzhiyun } 105