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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2007-2010 Red Hat, Inc.
4 * by Peter Jones <pjones@redhat.com>
5 * Copyright 2007 IBM, Inc.
6 * by Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
7 * Copyright 2008
8 * by Konrad Rzeszutek <ketuzsezr@darnok.org>
9 *
10 * This code finds the iSCSI Boot Format Table.
11 */
12
13#include <linux/memblock.h>
14#include <linux/blkdev.h>
15#include <linux/ctype.h>
16#include <linux/device.h>
17#include <linux/efi.h>
18#include <linux/err.h>
19#include <linux/init.h>
20#include <linux/limits.h>
21#include <linux/module.h>
22#include <linux/pci.h>
23#include <linux/stat.h>
24#include <linux/string.h>
25#include <linux/types.h>
26#include <linux/acpi.h>
27#include <linux/iscsi_ibft.h>
28
29#include <asm/mmzone.h>
30
31/*
32 * Physical location of iSCSI Boot Format Table.
33 */
34struct acpi_table_ibft *ibft_addr;
35EXPORT_SYMBOL_GPL(ibft_addr);
36
37static const struct {
38 char *sign;
39} ibft_signs[] = {
40 { "iBFT" },
41 { "BIFT" }, /* Broadcom iSCSI Offload */
42};
43
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
50static int __init find_ibft_in_mem(void)
51{
52 unsigned long pos;
53 unsigned int len = 0;
54 void *virt;
55 int i;
56
57 for (pos = IBFT_START; pos < IBFT_END; pos += 16) {
58 /* The table can't be inside the VGA BIOS reserved space,
59 * so skip that area */
60 if (pos == VGA_MEM)
61 pos += VGA_SIZE;
62 virt = isa_bus_to_virt(pos);
63
64 for (i = 0; i < ARRAY_SIZE(ibft_signs); i++) {
65 if (memcmp(virt, ibft_signs[i].sign, IBFT_SIGN_LEN) ==
66 0) {
67 unsigned long *addr =
68 (unsigned long *)isa_bus_to_virt(pos + 4);
69 len = *addr;
70 /* if the length of the table extends past 1M,
71 * the table cannot be valid. */
72 if (pos + len <= (IBFT_END-1)) {
73 ibft_addr = (struct acpi_table_ibft *)virt;
74 pr_info("iBFT found at 0x%lx.\n", pos);
75 goto done;
76 }
77 }
78 }
79 }
80done:
81 return len;
82}
83/*
84 * Routine used to find the iSCSI Boot Format Table. The logical
85 * kernel address is set in the ibft_addr global variable.
86 */
87unsigned long __init find_ibft_region(unsigned long *sizep)
88{
89 ibft_addr = NULL;
90
91 /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
92 * only use ACPI for this */
93
94 if (!efi_enabled(EFI_BOOT))
95 find_ibft_in_mem();
96
97 if (ibft_addr) {
98 *sizep = PAGE_ALIGN(ibft_addr->header.length);
99 return (u64)virt_to_phys(ibft_addr);
100 }
101
102 *sizep = 0;
103 return 0;
104}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2007-2010 Red Hat, Inc.
4 * by Peter Jones <pjones@redhat.com>
5 * Copyright 2007 IBM, Inc.
6 * by Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
7 * Copyright 2008
8 * by Konrad Rzeszutek <ketuzsezr@darnok.org>
9 *
10 * This code finds the iSCSI Boot Format Table.
11 */
12
13#include <linux/memblock.h>
14#include <linux/blkdev.h>
15#include <linux/ctype.h>
16#include <linux/device.h>
17#include <linux/efi.h>
18#include <linux/err.h>
19#include <linux/init.h>
20#include <linux/limits.h>
21#include <linux/module.h>
22#include <linux/pci.h>
23#include <linux/stat.h>
24#include <linux/string.h>
25#include <linux/types.h>
26#include <linux/acpi.h>
27#include <linux/iscsi_ibft.h>
28
29#include <asm/mmzone.h>
30
31/*
32 * Physical location of iSCSI Boot Format Table.
33 */
34phys_addr_t ibft_phys_addr;
35EXPORT_SYMBOL_GPL(ibft_phys_addr);
36
37static const struct {
38 char *sign;
39} ibft_signs[] = {
40 { "iBFT" },
41 { "BIFT" }, /* Broadcom iSCSI Offload */
42};
43
44#define IBFT_SIGN_LEN 4
45#define VGA_MEM 0xA0000 /* VGA buffer */
46#define VGA_SIZE 0x20000 /* 128kB */
47
48/*
49 * Routine used to find and reserve the iSCSI Boot Format Table
50 */
51void __init reserve_ibft_region(void)
52{
53 unsigned long pos, virt_pos = 0;
54 unsigned int len = 0;
55 void *virt = NULL;
56 int i;
57
58 ibft_phys_addr = 0;
59
60 /* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
61 * only use ACPI for this
62 */
63 if (efi_enabled(EFI_BOOT))
64 return;
65
66 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;
71
72 /* Map page by page */
73 if (offset_in_page(pos) == 0) {
74 if (virt)
75 early_memunmap(virt, PAGE_SIZE);
76 virt = early_memremap_ro(pos, PAGE_SIZE);
77 virt_pos = pos;
78 }
79
80 for (i = 0; i < ARRAY_SIZE(ibft_signs); i++) {
81 if (memcmp(virt + (pos - virt_pos), ibft_signs[i].sign,
82 IBFT_SIGN_LEN) == 0) {
83 unsigned long *addr =
84 (unsigned long *)(virt + pos - virt_pos + 4);
85 len = *addr;
86 /* if the length of the table extends past 1M,
87 * the table cannot be valid. */
88 if (pos + len <= (IBFT_END-1)) {
89 ibft_phys_addr = pos;
90 memblock_reserve(ibft_phys_addr, PAGE_ALIGN(len));
91 pr_info("iBFT found at %pa.\n", &ibft_phys_addr);
92 goto out;
93 }
94 }
95 }
96 }
97
98out:
99 early_memunmap(virt, PAGE_SIZE);
100}