linux/drivers/firmware/iscsi_ibft_find.c
Jan Beulich ed3c661448 iSCSI/iBFT: use proper address translation
In virtual environments (namely, Xen Dom0) virt <-> phys and
virt <-> isa-bus translations cannot be freely interchanged (and
even outside such environments it is not really correct to do so).
When looking at memory below 1M, the latter translations should
always be used.

iscsi_ibft_find.c part from: Martin Wilck <martin.wilck@ts.fujitsu.com>.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Konrad Rzeszutek Wilk <ketuzsezs@darnok.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-05 12:05:40 -07:00

84 lines
2.2 KiB
C

/*
* Copyright 2007 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/err.h>
#include <linux/init.h>
#include <linux/limits.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/string.h>
#include <linux/types.h>
#include <asm/mmzone.h>
/*
* Physical location of iSCSI Boot Format Table.
*/
struct ibft_table_header *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 */
/*
* Routine used to find the iSCSI Boot Format Table. The logical
* kernel address is set in the ibft_addr global variable.
*/
void __init reserve_ibft_region(void)
{
unsigned long pos;
unsigned int len = 0;
void *virt;
ibft_addr = NULL;
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 ibft_table_header *)virt;
break;
}
}
}
if (ibft_addr)
reserve_bootmem(pos, PAGE_ALIGN(len), BOOTMEM_DEFAULT);
}