// SPDX-License-Identifier: GPL-2.0-only /* * Copyright 2007-2010 Red Hat, Inc. * by Peter Jones <pjones@redhat.com> * Copyright 2007 IBM, Inc. * by Konrad Rzeszutek <konradr@linux.vnet.ibm.com> * Copyright 2008 * by Konrad Rzeszutek <ketuzsezr@darnok.org> * * This code finds the iSCSI Boot Format Table. */ #include <linux/memblock.h> #include <linux/blkdev.h> #include <linux/ctype.h> #include <linux/device.h> #include <linux/efi.h> #include <linux/err.h> #include <linux/init.h> #include <linux/limits.h> #include <linux/module.h> #include <linux/pci.h> #include <linux/stat.h> #include <linux/string.h> #include <linux/types.h> #include <linux/acpi.h> #include <linux/iscsi_ibft.h> #include <asm/mmzone.h> /* * Physical location of iSCSI Boot Format Table. */ struct acpi_table_ibft *ibft_addr; EXPORT_SYMBOL_GPL(ibft_addr); static const struct { char *sign; } ibft_signs[] = { { "iBFT" }, { "BIFT" }, /* Broadcom iSCSI Offload */ }; #define IBFT_SIGN_LEN 4 #define IBFT_START 0x80000 /* 512kB */ #define IBFT_END 0x100000 /* 1MB */ #define VGA_MEM 0xA0000 /* VGA buffer */ #define VGA_SIZE 0x20000 /* 128kB */ static int __init find_ibft_in_mem(void) { unsigned long pos; unsigned int len = 0; void *virt; int i; for (pos = IBFT_START; pos < IBFT_END; pos += 16) { /* The table can't be inside the VGA BIOS reserved space, * so skip that area */ if (pos == VGA_MEM) pos += VGA_SIZE; virt = isa_bus_to_virt(pos); for (i = 0; i < ARRAY_SIZE(ibft_signs); i++) { if (memcmp(virt, ibft_signs[i].sign, IBFT_SIGN_LEN) == 0) { unsigned long *addr = (unsigned long *)isa_bus_to_virt(pos + 4); len = *addr; /* if the length of the table extends past 1M, * the table cannot be valid. */ if (pos + len <= (IBFT_END-1)) { ibft_addr = (struct acpi_table_ibft *)virt; pr_info("iBFT found at 0x%lx.\n", pos); goto done; } } } } done: return len; } /* * Routine used to find the iSCSI Boot Format Table. The logical * kernel address is set in the ibft_addr global variable. */ unsigned long __init find_ibft_region(unsigned long *sizep) { ibft_addr = NULL; /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will * only use ACPI for this */ if (!efi_enabled(EFI_BOOT)) find_ibft_in_mem(); if (ibft_addr) { *sizep = PAGE_ALIGN(ibft_addr->header.length); return (u64)virt_to_phys(ibft_addr); } *sizep = 0; return 0; }