blob: 64bb945232819b288e512c5f21ada5dd5773a390 [file] [log] [blame] [edit]
// 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;
}