| // 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. |
| */ |
| phys_addr_t ibft_phys_addr; |
| EXPORT_SYMBOL_GPL(ibft_phys_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 */ |
| |
| /* |
| * Routine used to find and reserve the iSCSI Boot Format Table |
| */ |
| void __init reserve_ibft_region(void) |
| { |
| unsigned long pos; |
| unsigned int len = 0; |
| void *virt; |
| int i; |
| |
| ibft_phys_addr = 0; |
| |
| /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will |
| * only use ACPI for this |
| */ |
| if (efi_enabled(EFI_BOOT)) |
| return; |
| |
| 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_phys_addr = pos; |
| memblock_reserve(ibft_phys_addr, PAGE_ALIGN(len)); |
| pr_info("iBFT found at %pa.\n", &ibft_phys_addr); |
| return; |
| } |
| } |
| } |
| } |
| } |