Merge branch 'devel' of master.kernel.org:/home/rmk/linux-2.6-arm
[linux-2.6-block.git] / drivers / firmware / iscsi_ibft_find.c
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1/*
2 * Copyright 2007 Red Hat, Inc.
3 * by Peter Jones <pjones@redhat.com>
4 * Copyright 2007 IBM, Inc.
5 * by Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
6 * Copyright 2008
7 * by Konrad Rzeszutek <ketuzsezr@darnok.org>
8 *
9 * This code finds the iSCSI Boot Format Table.
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License v2.0 as published by
13 * the Free Software Foundation
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 */
20
21#include <linux/bootmem.h>
22#include <linux/blkdev.h>
23#include <linux/ctype.h>
24#include <linux/device.h>
25#include <linux/err.h>
26#include <linux/init.h>
27#include <linux/limits.h>
28#include <linux/module.h>
29#include <linux/pci.h>
30#include <linux/slab.h>
31#include <linux/stat.h>
32#include <linux/string.h>
33#include <linux/types.h>
34
35#include <asm/mmzone.h>
36
37/*
38 * Physical location of iSCSI Boot Format Table.
39 */
40struct ibft_table_header *ibft_addr;
41EXPORT_SYMBOL_GPL(ibft_addr);
42
43#define IBFT_SIGN "iBFT"
44#define IBFT_SIGN_LEN 4
45#define IBFT_START 0x80000 /* 512kB */
46#define IBFT_END 0x100000 /* 1MB */
47#define VGA_MEM 0xA0000 /* VGA buffer */
48#define VGA_SIZE 0x20000 /* 128kB */
49
50
51/*
52 * Routine used to find the iSCSI Boot Format Table. The logical
53 * kernel address is set in the ibft_addr global variable.
54 */
55void __init reserve_ibft_region(void)
56{
57 unsigned long pos;
58 unsigned int len = 0;
59 void *virt;
60
a01e035e 61 ibft_addr = NULL;
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62
63 for (pos = IBFT_START; pos < IBFT_END; pos += 16) {
64 /* The table can't be inside the VGA BIOS reserved space,
65 * so skip that area */
66 if (pos == VGA_MEM)
67 pos += VGA_SIZE;
68 virt = phys_to_virt(pos);
69 if (memcmp(virt, IBFT_SIGN, IBFT_SIGN_LEN) == 0) {
70 unsigned long *addr =
71 (unsigned long *)phys_to_virt(pos + 4);
72 len = *addr;
73 /* if the length of the table extends past 1M,
74 * the table cannot be valid. */
75 if (pos + len <= (IBFT_END-1)) {
76 ibft_addr = (struct ibft_table_header *)virt;
77 break;
78 }
79 }
80 }
81 if (ibft_addr)
82 reserve_bootmem(pos, PAGE_ALIGN(len), BOOTMEM_DEFAULT);
83}