linux/drivers/firmware/iscsi_ibft_find.c
Konrad Rzeszutek Wilk 1303a35bfe ibft: For UEFI machines actually do scan ACPI for iBFT.
For machines with IBFT 1.03 do scan the ACPI table for 'iBFT'
or for 'IBFT'. If the machine is in UEFI mode, only do the ACPI
table scan. For all other machines (pre IBFT 1.03) do
a memory scan if not found in the ACPI tables.

Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
Tested-by: Mike Christie <michaelc@cs.wisc.edu>
2010-05-11 13:02:37 -04:00

120 lines
3.0 KiB
C

/*
* 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", 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;
}