blob: 2192456dfd68329a97881c6103d4a4f2e66753eb [file] [log] [blame]
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -07001/*
Peter Jones4e639fd2010-02-25 15:37:17 -05002 * Copyright 2007-2010 Red Hat, Inc.
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -07003 * 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>
Peter Jones4e639fd2010-02-25 15:37:17 -050025#include <linux/efi.h>
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -070026#include <linux/err.h>
27#include <linux/init.h>
28#include <linux/limits.h>
29#include <linux/module.h>
30#include <linux/pci.h>
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -070031#include <linux/stat.h>
32#include <linux/string.h>
33#include <linux/types.h>
Peter Jones4e639fd2010-02-25 15:37:17 -050034#include <linux/acpi.h>
35#include <linux/iscsi_ibft.h>
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -070036
37#include <asm/mmzone.h>
38
39/*
40 * Physical location of iSCSI Boot Format Table.
41 */
Peter Jones4e639fd2010-02-25 15:37:17 -050042struct acpi_table_ibft *ibft_addr;
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -070043EXPORT_SYMBOL_GPL(ibft_addr);
44
45#define IBFT_SIGN "iBFT"
46#define IBFT_SIGN_LEN 4
47#define IBFT_START 0x80000 /* 512kB */
48#define IBFT_END 0x100000 /* 1MB */
49#define VGA_MEM 0xA0000 /* VGA buffer */
50#define VGA_SIZE 0x20000 /* 128kB */
51
Peter Jones4e639fd2010-02-25 15:37:17 -050052#ifdef CONFIG_ACPI
53static int __init acpi_find_ibft(struct acpi_table_header *header)
54{
55 ibft_addr = (struct acpi_table_ibft *)header;
56 return 0;
57}
58#endif /* CONFIG_ACPI */
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -070059
Konrad Rzeszutek Wilk1303a352010-04-08 12:35:55 -040060static int __init find_ibft_in_mem(void)
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -070061{
62 unsigned long pos;
63 unsigned int len = 0;
64 void *virt;
65
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -070066 for (pos = IBFT_START; pos < IBFT_END; pos += 16) {
67 /* The table can't be inside the VGA BIOS reserved space,
68 * so skip that area */
69 if (pos == VGA_MEM)
70 pos += VGA_SIZE;
Jan Beuliched3c6612009-10-02 16:12:39 +010071 virt = isa_bus_to_virt(pos);
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -070072 if (memcmp(virt, IBFT_SIGN, IBFT_SIGN_LEN) == 0) {
73 unsigned long *addr =
Jan Beuliched3c6612009-10-02 16:12:39 +010074 (unsigned long *)isa_bus_to_virt(pos + 4);
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -070075 len = *addr;
76 /* if the length of the table extends past 1M,
77 * the table cannot be valid. */
78 if (pos + len <= (IBFT_END-1)) {
Peter Jones4e639fd2010-02-25 15:37:17 -050079 ibft_addr = (struct acpi_table_ibft *)virt;
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -070080 break;
81 }
82 }
83 }
Konrad Rzeszutek Wilk1303a352010-04-08 12:35:55 -040084 return len;
85}
86/*
87 * Routine used to find the iSCSI Boot Format Table. The logical
88 * kernel address is set in the ibft_addr global variable.
89 */
90unsigned long __init find_ibft_region(unsigned long *sizep)
91{
92
93 ibft_addr = NULL;
94
Peter Jones4e639fd2010-02-25 15:37:17 -050095#ifdef CONFIG_ACPI
96 /*
97 * One spec says "IBFT", the other says "iBFT". We have to check
98 * for both.
99 */
100 if (!ibft_addr)
101 acpi_table_parse(ACPI_SIG_IBFT, acpi_find_ibft);
102 if (!ibft_addr)
Peter Jones57a5f3c2010-05-12 10:12:53 -0400103 acpi_table_parse(IBFT_SIGN, acpi_find_ibft);
Peter Jones4e639fd2010-02-25 15:37:17 -0500104#endif /* CONFIG_ACPI */
Konrad Rzeszutek Wilk1303a352010-04-08 12:35:55 -0400105
106 /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
107 * only use ACPI for this */
108
109 if (!ibft_addr && !efi_enabled)
110 find_ibft_in_mem();
111
Yinghai Lu042be382010-04-01 14:32:43 -0700112 if (ibft_addr) {
Peter Jones4e639fd2010-02-25 15:37:17 -0500113 *sizep = PAGE_ALIGN(ibft_addr->header.length);
114 return (u64)isa_virt_to_bus(ibft_addr);
Yinghai Lu042be382010-04-01 14:32:43 -0700115 }
116
117 *sizep = 0;
118 return 0;
Konrad Rzeszutek138fe4e2008-04-09 19:50:41 -0700119}