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/*
* 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.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License v2.0 as published by
* the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/bootmem.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);
#define IBFT_SIGN "iBFT"
#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 */
#ifdef CONFIG_ACPI
static int __init acpi_find_ibft(struct acpi_table_header *header)
{
ibft_addr = (struct acpi_table_ibft *)header;
return 0;
}
#endif /* CONFIG_ACPI */
static int __init find_ibft_in_mem(void)
{
unsigned long pos;
unsigned int len = 0;
void *virt;
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);
if (memcmp(virt, IBFT_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;
break;
}
}
}
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;
#ifdef CONFIG_ACPI
/*
* One spec says "IBFT", the other says "iBFT". We have to check
* for both.
*/
if (!ibft_addr)
acpi_table_parse(ACPI_SIG_IBFT, acpi_find_ibft);
if (!ibft_addr)
acpi_table_parse(IBFT_SIGN, acpi_find_ibft);
#endif /* CONFIG_ACPI */
/* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
* only use ACPI for this */
if (!ibft_addr && !efi_enabled)
find_ibft_in_mem();
if (ibft_addr) {
*sizep = PAGE_ALIGN(ibft_addr->header.length);
return (u64)isa_virt_to_bus(ibft_addr);
}
*sizep = 0;
return 0;
}
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