tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Copyright 2007-2010 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/efi.h>
26#include <linux/err.h>
27#include <linux/init.h>
28#include <linux/limits.h>
29#include <linux/module.h>
30#include <linux/pci.h>
31#include <linux/stat.h>
32#include <linux/string.h>
33#include <linux/types.h>
34#include <linux/acpi.h>
35#include <linux/iscsi_ibft.h>
36
37#include <asm/mmzone.h>
38
39/*
40 * Physical location of iSCSI Boot Format Table.
41 */
42struct acpi_table_ibft *ibft_addr;
43EXPORT_SYMBOL_GPL(ibft_addr);
44
45static const struct {
46 char *sign;
47} ibft_signs[] = {
48#ifdef CONFIG_ACPI
49 /*
50 * One spec says "IBFT", the other says "iBFT". We have to check
51 * for both.
52 */
53 { ACPI_SIG_IBFT },
54#endif
55 { "iBFT" },
56 { "BIFT" }, /* Broadcom iSCSI Offload */
57};
58
59#define IBFT_SIGN_LEN 4
60#define IBFT_START 0x80000 /* 512kB */
61#define IBFT_END 0x100000 /* 1MB */
62#define VGA_MEM 0xA0000 /* VGA buffer */
63#define VGA_SIZE 0x20000 /* 128kB */
64
65#ifdef CONFIG_ACPI
66static int __init acpi_find_ibft(struct acpi_table_header *header)
67{
68 ibft_addr = (struct acpi_table_ibft *)header;
69 return 0;
70}
71#endif /* CONFIG_ACPI */
72
73static int __init find_ibft_in_mem(void)
74{
75 unsigned long pos;
76 unsigned int len = 0;
77 void *virt;
78 int i;
79
80 for (pos = IBFT_START; pos < IBFT_END; pos += 16) {
81 /* The table can't be inside the VGA BIOS reserved space,
82 * so skip that area */
83 if (pos == VGA_MEM)
84 pos += VGA_SIZE;
85 virt = isa_bus_to_virt(pos);
86
87 for (i = 0; i < ARRAY_SIZE(ibft_signs); i++) {
88 if (memcmp(virt, ibft_signs[i].sign, IBFT_SIGN_LEN) ==
89 0) {
90 unsigned long *addr =
91 (unsigned long *)isa_bus_to_virt(pos + 4);
92 len = *addr;
93 /* if the length of the table extends past 1M,
94 * the table cannot be valid. */
95 if (pos + len <= (IBFT_END-1)) {
96 ibft_addr = (struct acpi_table_ibft *)virt;
97 goto done;
98 }
99 }
100 }
101 }
102done:
103 return len;
104}
105/*
106 * Routine used to find the iSCSI Boot Format Table. The logical
107 * kernel address is set in the ibft_addr global variable.
108 */
109unsigned long __init find_ibft_region(unsigned long *sizep)
110{
111#ifdef CONFIG_ACPI
112 int i;
113#endif
114 ibft_addr = NULL;
115
116#ifdef CONFIG_ACPI
117 for (i = 0; i < ARRAY_SIZE(ibft_signs) && !ibft_addr; i++)
118 acpi_table_parse(ibft_signs[i].sign, acpi_find_ibft);
119#endif /* CONFIG_ACPI */
120
121 /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
122 * only use ACPI for this */
123
124 if (!ibft_addr && !efi_enabled)
125 find_ibft_in_mem();
126
127 if (ibft_addr) {
128 *sizep = PAGE_ALIGN(ibft_addr->header.length);
129 return (u64)isa_virt_to_bus(ibft_addr);
130 }
131
132 *sizep = 0;
133 return 0;
134}